From popserver Wed Nov 1 17:00:42 GMT 1995 X-VM-Summary-Format: "%n %*%a %-17.17F %-3.3m %2d %4l/%-5c %I\"%s\"\n" X-VM-Labels: nil X-VM-VHeader: ("Resent-" "From:" "Sender:" "To:" "Apparently-To:" "Cc:" "Subject:" "Date:") nil X-VM-Bookmark: 146 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1198" "Wed" "1" "November" "1995" "15:50:49" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "28" "Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA17141; Wed, 1 Nov 95 06:50:42 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA01408 (5.67b/IDA-1.5 for ); Wed, 1 Nov 1995 15:50:19 +0100 Message-Id: <199511011450.AA01408@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815245202.002 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, hedmarc@cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Mini SD-newsletter Date: Wed, 01 Nov 1995 15:50:49 +0100 Subject: Pre-loading the decell track >From : Timothy To : Kelly and Others >>> The idea of pre-launcing fuel (brought up by Timothy >>> VanderLinden et. al.) is great for getting up to speed, but >>> I want to see how they intend to pre-load the decell track. >> >> Hey that was my idea! I agree with the problem with a decel track thou. If >> we could do that the ship systems would be a snap. > >I know it was your idea, but they brought it up most recently and also >said they had the math to back it up. "Sure would like to see it", thats what I told Nick. Nick and I discussed a lot about that, but REAL maths were not involved as far as I knew. This does not mean that we didn't agree. Pre-loading the decelleration track would not be troublesome if one could aim the "cannon"/"lineac" precise enough. But about this aiming problem we did not agree. If it is not clear to anyone how to pre-load the decell track, assuming there is no aiming problem, I wouldn't mind to explain, just ask me some specific questions. Greetings Timothy P.S. My name is Timothy van der Linden, I'm a real Dutchman so the contraction to "VanderLinden" does not apply. From popserver Thu Nov 2 00:41:33 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1343" "Wed" "1" "November" "1995" "19:35:37" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "30" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA23961; Wed, 1 Nov 95 16:35:18 PST Received: by mail06.mail.aol.com (8.6.12/8.6.12) id TAA09236; Wed, 1 Nov 1995 19:35:37 -0500 Message-Id: <951101193537_10158014@mail06.mail.aol.com> X-UIDL: 815272853.000 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, hedmarc@cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Mini SD-newsletter Date: Wed, 1 Nov 1995 19:35:37 -0500 >>> The idea of pre-launcing fuel (brought up by Timothy >>> VanderLinden et. al.) is great for getting up to speed, but >>> I want to see how they intend to pre-load the decell track. >> >> Hey that was my idea! I agree with the problem with a decel track thou. If >> we could do that the ship systems would be a snap. > >I know it was your idea, but they brought it up most recently and also >said they had the math to back it up. >> "Sure would like to see it", thats what I told Nick. Nick and >> I discussed a lot about that, but REAL maths were not >> involved as far as I knew. This does not mean that we >> didn't agree. Pre-loading the decelleration track would >> not be troublesome if one could aim the "cannon"/" >> lineac" precise enough. But about this aiming problem >> we did not agree. If it is not clear to anyone how to >> pre-load the decell track, assuming there is no aiming >> problem, I wouldn't mind to explain, just ask me some >> specific questions. Hi Tim, Ok, how do you get the decel fuel in the Target star systems decel track, and at an acceptable speed? To get their befor the ship it would have to be going at relativistic speeds. But if its going that fast, the ship couldn't catch its decel fuel. i.e. the ship would slow down, but the fuel wouldn't. Kelly From popserver Fri Nov 3 17:03:03 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1836" "Fri" "3" "November" "1995" "17:14:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "35" "Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA18472; Fri, 3 Nov 95 08:15:38 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA20356 (5.67b/IDA-1.5 for ); Fri, 3 Nov 1995 17:14:44 +0100 Message-Id: <199511031614.AA20356@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815418109.015 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, hedmarc@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca, T.L.G.vanderLinden@student.utwente.nl Subject: Mini SD-newsletter Date: Fri, 03 Nov 1995 17:14:59 +0100 Subject: Pre-loading the decell track Author : Timothy ReplyTo: Kelly >Ok, how do you get the decel fuel in the Target star systems decel track, and >at an acceptable speed? To get their befor the ship it would have to be >going at relativistic speeds. But if its going that fast, the ship couldn't >catch its decel fuel. i.e. the ship would slow down, but the fuel wouldn't. Another way to get it at the target before the Asimov is to send it there before the Asimov is started. What I mean is that the slowest fuel-packets will be send from Earth many years before the Asimov starts moving to TC. These early packets have low speeds and thus take a long time to get to TC. Faster packets which will be catched up by the Asimov first will be send last but still before the Asimov has started. So now there is a long track of packets all at decreasing speeds. All these packets are moving towards TC and so is the Asimov, but the Asimov moves a little bit faster than the fastest moving packet and "near" TC it catches up with that packet. After catching that packet the Asimov slows down a bit, but not too much, so that it can catch up with the next packet which moved slower than the packet just catched. This process repeates many times, untill the Asimov has an reasonable slow velocity. Because all packets are launched before the Asimov starts we call it a PRE-load track. Now the trick is to have all packets at the right place at the right time and at the right speed. This surely would be possible if we could aim our lineac at Sol precise enough. Of course there is a minimum limit speed for the slowest and first package: The slower it moves the earlier it has to be send to TC. If we would need real slow packets we would need sending them now already. OK, I hope this is clear, if not, ask me once more. Timothy From popserver Fri Nov 3 17:03:07 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1940" "Fri" "3" "November" "1995" "08:36:45" "-0800" "Ric Hedman" "HEDMARC@cellpro.cellpro.com" nil "45" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from cellpro.com (mail.cellpro.com) by efn.efn.org (4.1/smail2.5/05-07-92) id AA19924; Fri, 3 Nov 95 08:37:56 PST Received: by cryovial.cellpro.com id <44801>; Fri, 3 Nov 1995 08:38:04 -0800 X-Nvlenv-01Date-Posted: 3-Nov-1995 8:36:54 -0800; at Bothell.CellPro In-Reply-To: <11009A30015C2979@-SMF-> References: <11009A30025C2979@-SMF-> Message-Id: <95Nov3.083804pst.44801@cryovial.cellpro.com> X-UIDL: 815418109.018 From: HEDMARC@cellpro.cellpro.com (Hedman, Ric) To: T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com Subject: Re: Mini SD-newsletter Date: Fri, 3 Nov 1995 08:36:45 -0800 >Another way to get it at the target before the Asimov is to send it there >before the Asimov is started. What I mean is that the slowest fuel-packets >will be send from Earth many years before the Asimov starts moving to TC. >These early packets have low speeds and thus take a long time to get to TC. >Faster packets which will be catched up by the Asimov first will be send >last but still before the Asimov has started. So now there is a long track >of packets all at decreasing speeds. All these packets are moving towards TC >and so is the Asimov, but the Asimov moves a little bit faster than the >fastest moving packet and "near" TC it catches up with that packet. After >catching that packet the Asimov slows down a bit, but not too much, so that >it can catch up with the next packet which moved slower than the packet just >catched. This process repeates many times, untill the Asimov has an >reasonable slow velocity. >Because all packets are launched before the Asimov starts we call it a >PRE-load track. Now the trick is to have all packets at the right place at >the right time and at the right speed. This surely would be possible if we >could aim our lineac at Sol precise enough. Of course there is a minimum >limit speed for the slowest and first package: The slower it moves the >earlier it has to be send to TC. If we would need real slow packets we would >need sending them now already. OK, so we have this traffic jamb of fuel cells in a long string heading to TC. Are the faster ones going to overtake the slower ones? How are these faster fuel cells going to avoid colliding with the slower ones. If you aim all these off by just little bits to avoid running up the tailpipe of the slower ones by the time you get close to TC they are fanned out all over the place. By the way I will up and running up at home tomorrow so you can send these to: rddesign@wolfenet.com from now on. Thanks Ric From popserver Sat Nov 4 06:32:07 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4854" "Sat" "4" "November" "1995" "00:29:38" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "95" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA14448; Fri, 3 Nov 95 22:30:32 PST Received: by maroon.tc.umn.edu; Sat, 4 Nov 95 00:29:39 -0600 In-Reply-To: <199511031614.AA20356@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 815466718.000 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, hedmarc@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Mini SD-newsletter Date: Sat, 4 Nov 1995 00:29:38 -0600 (CST) Subject: pre-loading the decell track Author: Kevin Houston Replying to Timothy > Subject: Pre-loading the decell track > Author : Timothy > ReplyTo: Kelly > > >Ok, how do you get the decel fuel in the Target star systems decel track, and > >at an acceptable speed? To get their befor the ship it would have to be > >going at relativistic speeds. But if its going that fast, the ship couldn't > >catch its decel fuel. i.e. the ship would slow down, but the fuel wouldn't. > > Another way to get it at the target before the Asimov is to send it there > before the Asimov is started. What I mean is that the slowest fuel-packets > will be send from Earth many years before the Asimov starts moving to TC. > These early packets have low speeds and thus take a long time to get to TC. > Faster packets which will be catched up by the Asimov first will be send > last but still before the Asimov has started. So now there is a long track > of packets all at decreasing speeds. All these packets are moving towards TC > and so is the Asimov, but the Asimov moves a little bit faster than the > fastest moving packet and "near" TC it catches up with that packet. After > catching that packet the Asimov slows down a bit, but not too much, so that > it can catch up with the next packet which moved slower than the packet just > catched. This process repeates many times, untill the Asimov has an > reasonable slow velocity. > Yes, but at some point in the deceleration we will have to be moving at some arbitraily slow speed, let's say for the sake of argument that we want to see how the "Asimov" gets fuel while moving at .01 C (a speed of 3 million meters a second) in order to get fuel to T.C. with a speed of 3E+06, it will have to be launched 1200 years before the ship! Even if you cut off the fuel supply at a speed of .1 C (and how can you slow down from this insane speed without fuel?) you'd need to launch fuel 120 years ahead of ship launch. The U.S. (or others by the way) political scene would never stay focused for that length of time. It's preety dicey as to whether or not they'd leave the maser beam alone for two years (earth time) never mind 120! I'm going to go out on a limb here and say that there is _no_ way you could pre-load the decell track of a target like Tau Ceti. Maybe, Just Maybe, You could do it for Alpha Centauri, but not Tau ceti. and since the target is Tau Ceti, we need a better way. Either beam the power, or figure out how to use the Interstellar Medium (ISM) as a brake. I say that beaming the power is the quickest easiest solution. To: all From: Kevin H. Re: Results of Vote (un official) Having looked through the replies (before the newsletter melted), it seemed that the majority opinion was for a continued presence at T.C. While this may seem unrealistic to some (shush Kelly ;) ) I think it is a reasonable goal. I don't think our job is to do an economic justification for the colony (or base) I think we only need to show that it is possible. If someone in the future should decide to use our design, I'm sure there will be many changes, and this is one of the first no doubt. So here is the proposal. 1) Purpose of the mission is to set up a permanent base at T.C. in order to study the system in-depth and possibly set up a colony if conditions warrant. Otherwise, the base is slated to be abandoned after all the research is done. Expected service life of base should be 50 Solar years, any permanant colony must be self-sufficient. 2) Some means of sustainable (closed-cycle) life support must be found. spare parts and supplies can be ferried (see #3 below) to T.C., but the daily bread must be home-grown. 3) Individual crew members must have a reasonable chance to get rotated back to earth and/or quit the mission at various intervals. i.e. , there must be regular "shuttle bus" service, and this must be cost effective 4) "Shuttle busses" can assume loaded accel and decel tracks, or conversly they can assume functioning maser transmitters in both systems. 5) The "Asimov" need not be returned to Earth, it can stay at T.C. and become the core of the base, it can be junked, or it can be fitted for another trip to some other star in the local neighborhood. if you intend to convert the "Asimov" to a base, please be specific in dual-use details. if you intend to refit it for another journey, how will you build the spacedock? what target would you select, and who will crew it? Maybe you have some other use for the "Asimov" (we could put a big sign on it that says "Colony ship for sale - Cheap!" if you don't get the joke, that just means you haven't played enough Marathon.) I think the next vote shold be on engine type, but that should probably wait until we can get the Newsletter back up and running. Kevin H. From popserver Sat Nov 4 17:26:46 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["831" "Sat" "4" "November" "1995" "16:00:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "21" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA27052; Sat, 4 Nov 95 07:01:02 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12655 (5.67b/IDA-1.5 for ); Sat, 4 Nov 1995 16:00:54 +0100 Message-Id: <199511041500.AA12655@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815505969.014 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Mini SD-newsletter Date: Sat, 04 Nov 1995 16:00:58 +0100 Subject: Preloading the decel-track Author : Timothy ReplyTo: Ric >OK, so we have this traffic jamb of fuel cells in a long string heading >to TC. Are the faster ones going to overtake the slower ones? How are >these faster fuel cells going to avoid colliding with the slower ones. If >you aim all these off by just little bits to avoid running up the >tailpipe of the slower ones by the time you get close to TC they are >fanned out all over the place. No, the faster ones are NOT going to overtake the slower ones. But of course all packets get course the get nearer to each other all the time. In fact if they where not captured near TC they would indeed overtake each other. What we have to do is send them in the right intervals so they don't overtake before TC. So fanning out the packets is not necessary. Timothy From popserver Sat Nov 4 17:26:47 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5384" "Sat" "4" "November" "1995" "16:01:03" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "114" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA27056; Sat, 4 Nov 95 07:01:10 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12661 (5.67b/IDA-1.5 for ); Sat, 4 Nov 1995 16:00:59 +0100 Message-Id: <199511041500.AA12661@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815505969.015 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Mini SD-newsletter Date: Sat, 04 Nov 1995 16:01:03 +0100 Subject: Pre-loading the decell track Author : Timothy ReplyTo: Kevin Houston >Yes, but at some point in the deceleration we will have to be moving at >some arbitraily slow speed, let's say for the sake of argument that we >want to see how the "Asimov" gets fuel while moving at .01 C (a speed of >3 million meters a second) in order to get fuel to T.C. with a speed of >3E+06, it will have to be launched 1200 years before the ship! I was aware of that problem and wrote it but you didn't quote that part, so I write it once more: < Of course there is a minimum limit speed for the slowest and first package: < The slower it moves the earlier it has to be send to TC. If we would need real < slow packets we would need sending them now already. I hadn't done any calculations, but am glad you did. Any speed less than top-speed would be a gain. 0.3c would be more acceptable with respect to 0.8c, but of course not enough. >Even if >you cut off the fuel supply at a speed of .1 C (and how can you slow down >from this insane speed without fuel?) OK you wonder how to decelerate even further? Easy, don't burn all the fuel from the packets as soon as you get a hold of them. OK, the ship gets a bit heavier and would be a bit more difficult to decelerate, but every system has some advantages. That extra bit of weight/fuel should be just enough to decelerate from 0.1c to 0.0c. >you'd need to launch fuel 120 years >ahead of ship launch. The U.S. (or others by the way) political scene >would never stay focused for that length of time. It's preety dicey as >to whether or not they'd leave the maser beam alone for two years (earth >time) never mind 120! Yes, 120 years is too much, but that would also mean that the energy costs would be spread over more years than using direct beaming. >I'm going to go out on a limb here and say that there is _no_ way you >could pre-load the decell track of a target like Tau Ceti. Maybe, Just >Maybe, You could do it for Alpha Centauri, but not Tau ceti. and since >the target is Tau Ceti, we need a better way. Either beam the power, or >figure out how to use the Interstellar Medium (ISM) as a brake. I say >that beaming the power is the quickest easiest solution. Hey I never said it was such a good idea, I only tried to show that pre-loading would be possible. As I am sure you know, both theories you mentioned have many hooks and eyes too. We still haven't done good calculations of what the energy costs would be for these theories. Timothy ------------------------------------------------------------------------- Subject: Results of Vote (un official) ReplyTo: Kevin H. Author : Timothy >Having looked through the replies (before the newsletter melted), it >seemed that the majority opinion was for a continued presence at T.C. >While this may seem unrealistic to some (shush Kelly ;) ) I think it is >a reasonable goal. I don't think our job is to do an economic >justification for the colony (or base) I think we only need to show that >it is possible. If someone in the future should decide to use our >design, I'm sure there will be many changes, and this is one of the first >no doubt. We "know" that it is possible, but don't ask at what cost. Economic justification depends on many things two of them are cost and profit. Going to TC at low cost (ie. slow speeds) means little profit (the "trip" takes a long time so the financiers would not be alive anymore). And even higher costs are not sure to give real profits. What I meant to say is that we not should loose all economic perspective. And if we can find a reason to go there why not use it. >So here is the proposal. >3) Individual crew members must have a reasonable chance to get rotated >back to earth and/or quit the mission at various intervals. i.e. , there >must be regular "shuttle bus" service, and this must be cost effective How long would people work around TC? At least 10 years would be reasonable. This means that you would be about 30 years away from Earth. Would you like that? I certainly wouldn't. Also this would imply that each person would cost twice as much as staying at TC. (Note that staying there does not mean suicide). >4) "Shuttle busses" can assume loaded accel and decel tracks, or >conversly they can assume functioning maser transmitters in both systems. Is it feasable that such a system can be build on TC in a short (10 year) period? My guess is that the "few" people that went with the Asimov have a lot of other things to do. >I think the next vote shold be on engine type, but that should probably >wait until we can get the Newsletter back up and running. How can we possibly vote on such a matter if we don't even know what amounts of energy and power or involved per design. The only propulsion system 'I' know exact numbers of is just the take-all-fuel-with-you method. I have done relativistic calculations for this method involving all kinds of fuel (chemical to antimatter). These calculations have not yet been send to LIT, since its are rather long derivation. I will make it available if any one likes to see it. Another possibility is that I just show one the final formula's. But even these are not pleasant to look at. My results about fuel:ship ratio seem to agree with those of Steve VanDevender, only he had not numbers about energy and power. Timothy From popserver Mon Nov 6 01:43:51 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1137" "Sun" "5" "November" "1995" "20:40:54" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "26" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA10062; Sun, 5 Nov 95 17:41:44 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id UAA06041; Sun, 5 Nov 1995 20:40:54 -0500 Message-Id: <951105204049_13706207@emout05.mail.aol.com> X-UIDL: 815622186.019 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, hedmarc@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Mini SD-newsletter Date: Sun, 5 Nov 1995 20:40:54 -0500 To : Timothy ReplyTo: Kelly >Ok, how do you get the decel fuel in the Target star systems decel track, and >at an acceptable speed? To get their befor the ship it would have to be >going at relativistic speeds. But if its going that fast, the ship couldn't >catch its decel fuel. i.e. the ship would slow down, but the fuel wouldn't. >> Another way to get it at the target before the Asimov is >> to send it there before the Asimov is started. What I >> mean is that the slowest fuel-packets will be send >> from Earth many years before the Asimov starts moving >> to TC. ---- Of course there is a minimum >> limit speed for the slowest and first package: The slower >> it moves the earlier it has to be send to TC. If we would >> need real slow packets we would need sending them now >> already. Thats the problem. 1) if the ship needs fuel for .2 C or less, for a Tau Ceti flight it would have to be launched about 60 years before the ship gets there. 2) To do all this precise launch timing decades before the flight leaves would be perfect assurence that the fuel and ship will NOT get together at the proper time. From popserver Mon Nov 6 01:48:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1107" "Sun" "5" "November" "1995" "20:41:24" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "25" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA10116; Sun, 5 Nov 95 17:43:25 PST Received: by emout06.mail.aol.com (8.6.12/8.6.12) id UAA27127; Sun, 5 Nov 1995 20:41:24 -0500 Message-Id: <951105204120_13706644@emout06.mail.aol.com> X-UIDL: 815622526.000 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Mini SD-newsletter Date: Sun, 5 Nov 1995 20:41:24 -0500 >Even if >you cut off the fuel supply at a speed of .1 C (and how can you slow down >from this insane speed without fuel?) >> OK you wonder how to decelerate even further? Easy, >> don't burn all the fuel from the packets as soon as you get >> a hold of them. OK, the ship gets a bit heavier and would >> be a bit more difficult to decelerate, but every system >> has some advantages. That extra bit of weight/fuel >> should be just enough to decelerate from 0.1c to 0.0c. Thats a very good point! If the fuel stream can get the ship down to a speed that it can decelerate down from with stored fuel, it could be done. SCheduling the flight precisly enough to intercept the fuel is a problem (assuming you can launch the fuel the precisely!) but again that would only be a problem for a first flight if you bring along equip to build fuel launchers in system. However gven the target of Tau Ceti, and the practical time limits of 20 years were talking about fuel at over 1/2 light speed. Oh, I suppose we'ld get some decel force out of the drage we'ld get from picking up the slower fuel. Kelly From popserver Mon Nov 6 01:53:58 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["612" "Sun" "5" "November" "1995" "19:51:14" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "19" "Re: Mini SD-newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA10606; Sun, 5 Nov 95 17:52:20 PST Received: by maroon.tc.umn.edu; Sun, 5 Nov 95 19:51:14 -0600 In-Reply-To: <951105204049_13706207@emout05.mail.aol.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 815622829.001 From: Kevin C Houston To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, hedmarc@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Mini SD-newsletter Date: Sun, 5 Nov 1995 19:51:14 -0600 (CST) On Sun, 5 Nov 1995 KellySt@aol.com wrote: > To : Timothy > > > Thats the problem. 1) if the ship needs fuel for .2 C or less, for a Tau > Ceti flight it would have to be launched about 60 years before the ship gets > there. 2) To do all this precise launch timing decades before the flight > leaves would be perfect assurence that the fuel and ship will NOT get > together at the proper time. > Agreed, The timing difficulties alone would make this a problematic approach. Granted it may be physically possible, but that does not mean that it's practical. I say "nice try guys", but no cigar. Kevin From popserver Mon Nov 6 16:59:58 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6783" "Mon" "6" "November" "1995" "13:01:56" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "146" "Engineering Oldies letter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA02591; Mon, 6 Nov 95 04:02:26 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA01975 (5.67b/IDA-1.5 for ); Mon, 6 Nov 1995 13:01:34 +0100 Message-Id: <199511061201.AA01975@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815677179.004 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Engineering Oldies letter Date: Mon, 06 Nov 1995 13:01:56 +0100 Just after the last official newsletter was send, I mailed these message to LIT. Because of this some messages seem to be very old, but their content still applies, so I send them here: To : All >From : Timothy Subject : Overheating I have serious doubts if we can cool the engine of the Asimov or the beaming-apparatus in solar orbit. If only a small fraction of the needed power is transferred to heat, things will melt or be blown away very fast. Since the power needed will be very big (1E18 Watt) only small portions (1E12=0.001%) that are not efficiently used can give real trouble. I don't think efficiecies of more than 99 percent are feasable. So, does any of you have a solution to this overheating problem? My guess is that cooling water would not work. And if the engine is on the Asimov the trouble would even be bigger, since space isn't much of a cooling fluid. To : Kevin >From : Timothy Re : Flat floors, curved walls >Yes they do flex, or else I missed something major. consider the hab >train while the ship is under acceleration let us designate the floor/ceiling >familiar trip, you notice that it is the distance between cabs at the top >of the cars that is shorter, and the distance near the floor that is longer. So far OK. >unless you want people to suit up every time they pass between cars, you >are going to have to have a flexible conduit for them to walk through. Nope, the junctions would indeed be curved but would be stationary. The shorter part would always be at the inside of the ring. Now only the tubes would need to turn. The connection between the junction and the tube would just be some turnable connection like a wheel that can rotate around an axis. To : Kevin Houston >From : Timothy van der Linden Re : MARS Design. >I agree that the momentum is large, but there will be many transmitters, >so each individual one may not be affected so much. However, if this >turns out not to be the case, the effect can be totally negated by a >but no trqansmitter should have to do this very often. Of course you >would have to double the amount of transmitters, because half of them >would be occulted by the Sun at any one time. Let us take 100 "cubes" weighing approx. 10 ton each: Total weigh 1E6 kg. Since the total weight of the cubes is much less than the MARS-design (M=2.5E9) their end-velocity would be greater than that of the Asimov. So their total weight should be at least 10 to 100 times bigger than that of the MARS-design if we don't want the cubes to leave our solar system. According to my calculations each one of the 100 "cubes" would get an acceleration of about 8000 m/s^2 if they wanted to power the Asimov. Since this is quite much the "cube" would be blown out of orbit before it could make one orbit around the Sun, so you add and subtract method would not work. Another problem will be that the collectors on the cubes will be blown away by the Sun's photons. You may think that photons don't have that much momentum. But I assure you that the amount of photons that have to be collected is big enough to do that. In fact you can compare a cube-collectors with a large mirror reflecting Sun's photons to the Asimov. This means that the collectors get twice the momentum of the the Asimov. My idea would be to build mirrors or solar panels with a maser on the moon or Mars. The only disadvantage is that the mirrors or panels should be larger but the advantage is that they would not need to be launched. To get some feel about the size we are talking about: The mean power we need would be at least 4E17 Joule/second. That would mean a collector with the size of 4.4E13 square metres in the same orbit as Mercury or one that is 20 times bigger on Mars. The problem is that Mars is not big enough! Having done thes calculations make me realize that the collectors that are attached to the cubes may weigh much much more than 6 ton and that making the collectors would be more difficult than making the Asimov. I hope I've not confused you by the numbers, but I really think they are right. (The value of 4E17 is an approximation. I first calculated the total kinetic energy of the Asimov with speed 0.74c and then devided that by the time it took to accelerate the Asimov to that speed.) As far as I can see it, direct solar power would not be feasable. To : Kevin >From : Timothy Re : Electrons and shielding. >We can't carry a UV laser with us, because it would never be the right >wavelength (due to doppler shifting) so it would have to be a Sol based >system. but if we are going to use a UV laser (to clear our path) then we >might as well use that to power our spacecraft, radically altering our >design. anyone know how to convert uv photons to electicity with the >nearly 90% efficeincy of a microwave converter? (me niether :( Clearing the way for the Asimov with a Sol based system would mean that all that is in between would be ionized as well. That would mean a lot of extra energy. I'm sure that in 2040 we have variable lasers in the UV-range. We now already have them in the visible range. >The only other way i know to ionize an atom, is to hit it with a positron. >not go where we wanted. I suppose we could emit some particle that would >be nuetral, but would then decay into positrons, but such a particle >would violate charge conservation (any ideas?) Such a particle would be a free anti-neutron it has a decay time of 10.6 minutes and its reaction products are a positron, an anti-electron and a anti-neutrino. But unfortunately anti-neutrons would cost too much energy to make for this purpose. >given all this, I think a simple erosion plate on the front of the ship >might be the best answer. something about 2000 meters in rad, and about >20 meters (just a guess) thick. shaped into a blunt cone (we do want to >travel at c for part of this trip). the incoming H,He,etc would hit >this, gouging pits and becomming imbeded. the overall force of this >material striking us would be the same no matter if we push it out of the >way with magnetic fields or let it impact a physical barrier. I guess that is like what I was saying all along. >Oh man, this gets more expensive (energy wise) by the minute. >Please, Please, somebody flame me and tell me i forgot something that >will let us ionize everything ahead of us and go back to using mag fields >for shields. I can't think of a single thing. we might have to limit >our top speed to some high fraction of c, won't add that much more to the >trip. let's say for arguments sake, that we limit ourselves to .95 C. I really think a variable laser onboard the Asimov could do the trick. From popserver Mon Nov 6 17:00:01 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["884" "Mon" "6" "November" "1995" "13:02:10" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "23" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA02590; Mon, 6 Nov 95 04:02:24 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA02048 (5.67b/IDA-1.5 for ); Mon, 6 Nov 1995 13:02:04 +0100 Message-Id: <199511061202.AA02048@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815677179.005 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Engineering Newsletter Date: Mon, 06 Nov 1995 13:02:10 +0100 OK, my theory strands on practical difficulties, so we are back to zero. So I quote Kevin (Newsletter 00:29 11-04-95) >Either beam the power, or >figure out how to use the Interstellar Medium (ISM) as a brake. I say >that beaming the power is the quickest easiest solution. Beaming the power would still mean a timing problem of about 10 years? And another problem for this method would be that you get a large amount of momentum in the wrong direction (ie. in the direction of TC). Using ISM would be great, but it seems that only VERY BIG scoops could do the trick. I still haven't seen a formula about a scoop field. Kevin you seem to have one, is it possible that I could see that formula? Maybe we should find a nearby star in a nebula, that sure would increase the ISM-density. I'm not sure if there are any nearby nebulae. Does someone know more about that? Timothy From popserver Mon Nov 6 23:52:47 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1646" "Mon" "6" "November" "1995" "17:48:30" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "44" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA12615; Mon, 6 Nov 95 15:49:21 PST Received: by maroon.tc.umn.edu; Mon, 6 Nov 95 17:48:38 -0600 In-Reply-To: <199511061202.AA02048@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 815701951.002 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Mon, 6 Nov 1995 17:48:30 -0600 (CST) On Mon, 6 Nov 1995, Timothy van der Linden wrote: > > OK, my theory strands on practical difficulties, so we are back to zero. > > So I quote Kevin (Newsletter 00:29 11-04-95) > > >Either beam the power, or > >figure out how to use the Interstellar Medium (ISM) as a brake. I say > >that beaming the power is the quickest easiest solution. > > Beaming the power would still mean a timing problem of about 10 years? And > another problem for this method would be that you get a large amount of > momentum in the wrong direction (ie. in the direction of TC). 1) about the timing problem. Since "Asimov" and the beam are traveling in the same direction, the beam starts at the same time that the "Asimov" does. Also, the beam only needs to be on for about 1.5 years due to relativistic effects 2) this isn't a maser sail, the momentum imparted by the beam itself is negligible compared to the momentum generated by the engine exhaust. and since the engine exhaust can be directed either foreward or backward, this is not a problem > > Using ISM would be great, but it seems that only VERY BIG scoops could do > the trick. I still haven't seen a formula about a scoop field. Kevin you > seem to have one, is it possible that I could see that formula? > I have posted it several times, i will do so again soon. i can't seem to locate it right now, but it's not hard to derivate > Maybe we should find a nearby star in a nebula, that sure would increase the > ISM-density. I'm not sure if there are any nearby nebulae. Does someone know > more about that? > then how do we get from the nebula to the target system? Kevin From popserver Tue Nov 7 18:54:05 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2618" "Tue" "7" "November" "1995" "12:11:57" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "61" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA16096; Tue, 7 Nov 95 03:11:59 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA02078 (5.67b/IDA-1.5 for ); Tue, 7 Nov 1995 12:11:44 +0100 Message-Id: <199511071111.AA02078@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 815770421.002 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Tue, 07 Nov 1995 12:11:57 +0100 ReplyTo: Kevin >1) about the timing problem. Since "Asimov" and the beam are traveling >in the same direction, the beam starts at the same time that the "Asimov" >does. Also, the beam only needs to be on for about 1.5 years due to >relativistic effects The Asimov will take at least 1 year to accelerate.So the beam won't start at the same time but at least 1 year later. Also the beam of photons travels with the speed of light so it has be beamed another 5 years later, so that it does not catch up with the Asimov prematurely. Besides that problem, the beam then still has to be aimed exactly at the place where the Asimov will be after about 15 years, and it should be there at that time and not a month later. Maybe I haven't used the correct To me this still seems to be a timing problem. If I'm wrong, tell me where. >2) this isn't a maser sail, the momentum imparted by the beam itself is >negligible compared to the momentum generated by the engine exhaust. and >since the engine exhaust can be directed either foreward or backward, >this is not a problem What matters is the energy:momentum ratio of the beamed power. For the photons in the beam that ratio is: E:p = c:1 where c=3E8 For the Asimov moving at 0.7 c that ratio is: E:p = 0.4c:1 The beam needs to have about 1/0.4=2.5 times less momentum than the Asimov, but that is still a lot, so I can't agree with you that the momentum of the beam is neglectable. Using a particle beam would make the problem worse because you would get the same energy:momentum ratio as the ship. Also a particle beam would mean that the amount of received particles increases as the Asimov slows down. >> Using ISM would be great, but it seems that only VERY BIG scoops could do >> the trick. I still haven't seen a formula about a scoop field. Kevin you >> seem to have one, is it possible that I could see that formula? >> >I have posted it several times, i will do so again soon. i can't seem to >locate it right now, but it's not hard to derivate OK, I look forward to it. (I haven't seen it in any newsletter for at least the last 4 months and don't know how I should derive it.) >> Maybe we should find a nearby star in a nebula, that sure would increase the >> ISM-density. I'm not sure if there are any nearby nebulae. Does someone know >> more about that? >> >then how do we get from the nebula to the target system? My hopes were that the star was in or nearby the nebula, so once you are almost to a standstill you are near your destination. Maybe a nebula implies lifeless planets, but I don't know enough about that. Timothy From popserver Thu Nov 9 22:56:16 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["601" "Thu" "9" "November" "1995" "17:51:33" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "18" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail02.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA24270; Thu, 9 Nov 95 14:52:29 PST Received: by mail02.mail.aol.com (8.6.12/8.6.12) id RAA15091; Thu, 9 Nov 1995 17:51:33 -0500 Message-Id: <951109175132_17750050@mail02.mail.aol.com> X-UIDL: 815957739.001 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl Cc: stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Thu, 9 Nov 1995 17:51:33 -0500 > ISM-density. I'm not sure if there are any nearby nebulae. > Does someone know more about that? Sorry this area of the galaxy is unusually empty. No nebula, and the stars are unusually far apart. Cooling the engines? Good point! The fusion engines I was talking about are 99.9+% efficent, but at the power levels were talking about we'ld melt the ship. We seem to have talked oiurselves out of all the engine concepts? We can't launch fuel over interstellar distences. The MARS system seems to need impossibly large collector arrays, and eiather system would cook the ship. bummer. Kelly From popserver Fri Nov 10 19:52:04 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6753" "Fri" "10" "November" "1995" "10:15:17" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "138" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA13547; Fri, 10 Nov 95 08:15:35 PST Received: by maroon.tc.umn.edu; Fri, 10 Nov 95 10:15:19 -0600 In-Reply-To: <199511071111.AA02078@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 816033034.034 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Fri, 10 Nov 1995 10:15:17 -0600 (CST) On Tue, 7 Nov 1995, Timothy van der Linden wrote: > ReplyTo: Kevin > > >1) about the timing problem. Since "Asimov" and the beam are traveling > >in the same direction, the beam starts at the same time that the "Asimov" > >does. Also, the beam only needs to be on for about 1.5 years due to > >relativistic effects > > The Asimov will take at least 1 year to accelerate.So the beam won't start > at the same time but at least 1 year later. Also the beam of photons travels > with the speed of light so it has be beamed another 5 years later, so that > it does not catch up with the Asimov prematurely. > Besides that problem, the beam then still has to be aimed exactly at the > place where the Asimov will be after about 15 years, and it should be there > at that time and not a month later. > Maybe I haven't used the correct > To me this still seems to be a timing problem. If I'm wrong, tell me where. Be glad to. First, the "Asimov" will need power from day one, so the beam will be on from day 1. Toward the center of the trip, the "Asimov" will be moving close to C, and will travel with the beam. if you look at the last day of the trip, you see that according to earth's clocks about 13.25 years have elapsed, but since TC is only 12 LY away, that means that the beam of energy left earth only 1.25 years after we did. Also, about "aiming", the maser beam will be a straight line between the two stars, we will follow the beam. there isn't really any "aiming" problem, there _is_ a "jitter" problem ie. how to keep the beam from pointing slightly away from TC and causing the poser to "wink" on and off years later at the "Asimov" > > >2) this isn't a maser sail, the momentum imparted by the beam itself is > >negligible compared to the momentum generated by the engine exhaust. and > >since the engine exhaust can be directed either foreward or backward, > >this is not a problem > > What matters is the energy:momentum ratio of the beamed power. > For the photons in the beam that ratio is: > > E:p = c:1 where c=3E8 > > For the Asimov moving at 0.7 c that ratio is: > > E:p = 0.4c:1 > > The beam needs to have about 1/0.4=2.5 times less momentum than the Asimov, > but that is still a lot, so I can't agree with you that the momentum of the > beam is neglectable. > > Using a particle beam would make the problem worse because you would get the > same energy:momentum ratio as the ship. Also a particle beam would mean that > the amount of received particles increases as the Asimov slows down. no, I am talking about the momentum of the photons as opposed to the momentum of the ions the "Asimov" will eject as exhaust. Those will be Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how much energy you can invest) C at these speeds, a small mass flow is sufficient to slow us down (or speed us up depending on which phase of the mission we are in) at a constant 1 G. Now, about the energy of photons/area of collectors/mass of collectors problem. Any of these so called problems can be solved by the same solution. namely increasing the number of collectors. Timothy, you were talking about the problems associated with 100 collectors/transmitters beaming power to the "Asimov" I agree with you, 100 transmitters is way too small. I was initially planning on 720 (one every half degree) transmitters, but there is no reason (aside from cost) that we can't have 7200, or 7.2 E 18 transmitters (each one sending a few watts of energy and costing ten dollars) increasing the number of transmitters will: reduce the amount of photon thrust that each transmitter is subjected to. reduce the amount of solar array that each trnsmitter must have. reduce the amount of beam jitter (by averaging the errors, they are reduced) reduce the heat load of each transmitter. (the non-Sol side of the solar panels will make an excellent heat radiator) increase the total cost of the mission (hey, you don't get nothing for free) Heat load on the asimov: I do not understand why people think this is a problem, that must mean that I am not seeing something. so, I will tell you why I think this is a non-issue (or even a benefit) . Heat generation will come from two sources. 1) (and the largest) conversion of microwaves to electricity. This takes place with between 85 - 90 percent efficiency, and for our purposes, 15% heat load (from 1E18 Watts) is still a lot. _BUT_ the conversion would take place on the antenna itself. diodes wired directly onto the metal mesh would do the power converting and the mesh (of special radiator fins if need be) could radiate the heat. we have thousands and thousands of square meters of antenna, it would serve as an exceptional radiator. Also, if we used "memory metal" in the antenna, the heat of conversion could be directed to hold the antenna rigid. _also_ Heat (for living quarters etc) radiates as the square of the size of the "Asimov", there will be little or no radiation coming into the living quarters, but a lot will be leaving. We are going to have to do an energy balance on the heat so we can determine the equilibrium temp of the living quarters. but my guess is that it will be on the chilly side, and so we may want all the heat we can get. 2) heat will be generated in the coils for the linear accelerator core. This can be minimized by using superconducting electromagnets, but there will always be inefficiencies. Assuming that we can get 99% efficiency out of superconductors, (not unreasonable) that means we will have to deal with 1 E16 watts of thermal energy. _BUT_ This will be spread out over the length of the entire core. also, we are going to have to raise the temp of the reaction mass from near Zero (kelvin) in the case of Hydrogen, to something approaching room temp (depends on which superconductors you use, we could use the old ceramic style ones, and limit ourselves to ~ 200 K I know a lot of people who'ld like to scrap their old ceramic superconductors for the newer room-temp ones, maybe we can save a buck or two and buy those up ;p ) (the reaction mass would then also serve to cool the superconductors) This heat, rather than the anntenna heat would probably be best suited to heating the living quarters. Surprisingly enough, the exhaust itself will not be all that hot. There is no chemical or fusion reaction going on in the exhaust, so the only heat is the heat we allow to go in from the coils on the magnets. whatever heat is left over, can easily be pumped (using hot water) to the outside of the ship. radiator fins along the length of the ship would radiate the heat into space. Kevin From popserver Fri Nov 10 19:52:08 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["976" "Fri" "10" "November" "1995" "10:24:01" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "27" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA13995; Fri, 10 Nov 95 08:24:15 PST Received: by maroon.tc.umn.edu; Fri, 10 Nov 95 10:24:02 -0600 Reply-To: Kevin C Houston In-Reply-To: <951109175132_17750050@mail02.mail.aol.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII X-UIDL: 816033034.036 From: Kevin C Houston Sender: Kevin C Houston To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Fri, 10 Nov 1995 10:24:01 -0600 (CST) To: all Re: LIT I just got a meassage from David saying that he is working hard on restoring the newsletters. I don't know if he sent the same message to everyone else or not, so i thought I'd pass this on. BTW, has anyone kept all copies of the Mini-LIT newsletter to put in the archives? I must admit I have not. And, Brian has written me saying that he no longer wants to get seven messages a day. I wasn't sure how long the current situation would continue, so I wasn't sure how to respond to this message. So what about it brian? You want us to delete your name from the cc: field, or do you want to hang around until the newsletter gets restored? please reply to everyone, so that we all know your wishes. Thanks. Kevin PS anyone else who wants to get deleted needs to respond here also. I am not the "keeper" of the newsletter, I am only one person talking to my friends over the internet. like all internet activities, this is a true anarchy. From popserver Fri Nov 10 19:52:23 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["627" "Fri" "10" "November" "1995" "11:57:29" "-0500" "Brian Van Straalen" "bpvanstr@yoho.uwaterloo.ca" nil "15" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from yoho.uwaterloo.ca by efn.efn.org (4.1/smail2.5/05-07-92) id AA15955; Fri, 10 Nov 95 08:57:04 PST Received: (from bpvanstr@localhost) by yoho.uwaterloo.ca (8.6.12/8.6.12UW) id LAA20473; Fri, 10 Nov 1995 11:57:29 -0500 Message-Id: <199511101657.LAA20473@yoho.uwaterloo.ca> In-Reply-To: from "Kevin C Houston" at Nov 10, 95 10:24:01 am X-Mailer: ELM [version 2.4 PL24] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 627 X-UIDL: 816033034.044 From: Brian Van Straalen To: hous0042@maroon.tc.umn.edu Cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Fri, 10 Nov 1995 11:57:29 -0500 (EST) > > And, Brian has written me saying that he no longer wants to get seven > messages a day. I wasn't sure how long the current situation would > continue, so I wasn't sure how to respond to this message. > > So what about it brian? You want us to delete your name from the cc: > field, or do you want to hang around until the newsletter gets restored? Seeing as there doesn't seem to be a time frame for re-establishing a newsletter format, I opt to be removed from the cc. field. It would be nice to be re-established into the list when a newsletter does get generated that I can be re-established. thanks, Brian From popserver Fri Nov 10 23:03:19 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4410" "Fri" "10" "November" "1995" "23:57:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "110" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA09458; Fri, 10 Nov 95 14:57:42 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24464 (5.67b/IDA-1.5 for ); Fri, 10 Nov 1995 23:57:52 +0100 Message-Id: <199511102257.AA24464@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 816044553.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Fri, 10 Nov 1995 23:57:58 +0100 ReplyTo : Kelly ReplyFrom: Timothy >We seem to have talked oiurselves out of all the engine concepts? We can't >launch fuel over interstellar distences. The MARS system seems to need >impossibly large collector arrays, and eiather system would cook the ship. > >bummer. Cheer up Kelly, we will find a way, we can always make a multi-generation ship, I guess. Subject : Photon energy ReplyTo : Kevin ReplyFrom: Timothy OK, I agree with you about the aiming and timing 'problem' I wrote you about. But I think I found another problem, so read on. >> What matters is the energy:momentum ratio of the beamed power. >> For the photons in the beam that ratio is: >> >> E:p = c:1 where c=3E8 >> >> For the Asimov moving at 0.7 c that ratio is: >> >> E:p = 0.4c:1 >> >> The beam needs to have about 1/0.4=2.5 times less momentum than the Asimov, >> but that is still a lot, so I can't agree with you that the momentum of the >> beam is neglectable. WARNING! I made a mistake here, I forgot that the momentum of the Asimov increased while it was receiving photons. So the best thing to do is forget the above. >no, I am talking about the momentum of the photons as opposed to the >momentum of the ions the "Asimov" will eject as exhaust. Those will be >Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how >much energy you can invest) C at these speeds, a small mass flow is >sufficient to slow us down (or speed us up depending on which phase of >the mission we are in) at a constant 1 G. This was clear to me, but rethinking this made me realize that your method can't work. Because adding momentum to the Asimov will only make it move faster. Transforming it to reverse momentum would surely break one of the basic physic laws. In formulas: - You shoot some photons at the Asimov, that will give an energy Up=p*c where p is the momentum of the photon. - To accelerate a mass M to speed v to decelerate the Asimov, we need an amount of energy Uk=M*c^2*(gamma-1). - We use all the energy of the received photons for that acceleration, so Up=Uk --> p*c=M*c^2(gamma-1) --> p=M*c*(gamma-1) - Thus to accellerate a mass M to speed v we need to receive photons which will add us a momentum of p=M*c*(gamma-1). - But of course we can subtract some momentum that we created by shooting that mass M away. That momentum equals to p=gamma*M*v. - Now the problem arises because by receiving photons we gain more momentum that we loose by shooting that mass M away. In physics: gamma*M*v is always less than M*c*(gamma-1) Subject : Solar array ReplyTo : Kevin ReplyFrom: Timothy >increasing the number of transmitters will: >reduce the amount of photon thrust that each transmitter is subjected to. >reduce the amount of solar array that each trnsmitter must have. >reduce the amount of beam jitter (by averaging the errors, they are reduced) >reduce the heat load of each transmitter. (the non-Sol side of the solar > panels will make an excellent heat radiator) >increase the total cost of the mission (hey, you don't get nothing for free) But it won't reduce the total solar array, which is really big: Total Solar Power : 4E26 Watts Area of a globe with radius 1E9 metres : 7.9E17 square metres -> Solar power per square metre : 5E8 Watt Mean amount of power needed by the Asimov : 1E18 Watt -> Size of solar array : 1E18/5E8 = 2E9 square metres = disc with radius 2.5E4 metres. Remember 1E9 metres is quite near Sol. You wouldn't like to be there in your space suit, because 5E8 Joules would be added to your body temperature every second. Subject : Overheating ReplyTo : Kevin ReplyFrom: Timothy The main solution for the energy-leak in your letter was 'radiate it away'. You say the antenna mesh can radiate it away. You assume the leaking-energy can be radiated away before it can do any damage. Let us assume that the leaking-energy is ordinary Ohmic resistance and thus emerges as heat in the mesh. I think that before it can radiate away the mesh is molten or has disappeared altogether. So my problem is wheter one can radiate it away fast enough. And if you seem to be able to guide the energy so well, why not use it. The amount of energy leaving the crew quarters should not be that much, It will probably some kind of thermos flask. From popserver Sun Nov 12 06:55:16 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2320" "Sat" "11" "November" "1995" "22:12:05" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "51" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail02.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA13959; Sat, 11 Nov 95 19:12:46 PST Received: by mail02.mail.aol.com (8.6.12/8.6.12) id WAA18549; Sat, 11 Nov 1995 22:12:05 -0500 Message-Id: <951111221204_104196661@mail02.mail.aol.com> X-UIDL: 816159261.001 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl Cc: stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Sat, 11 Nov 1995 22:12:05 -0500 >> Heat load on the asimov: >> Heat generation will come from two sources. >> 1) (and the largest) conversion of microwaves to >> electricity. This takes place with between 85 - 90 >> percent efficiency, and for our purposes, 15% >> heat load (from 1E18 Watts) is still a lot. >> _BUT_ >> the conversion would take place on the antenna itself. >> diodes wired directly onto the metal mesh would do the >> power converting and the mesh (of special radiator fins >> if need be) could radiate the heat. we have thousands and >> thousands of square meters of antenna, it would serve as >> an exceptional radiator. ---- I'll buy this part. With the hundreds to thousands of square kilometers of mesh you've been taling about you have a lot of radiator space. Asuming you can radiate the energy away fast enough to keep everything down to operating temperature. If you want supper conductors this could be dicy. They like cold temps and radiators like it very hot. >> 2) heat will be generated in the coils for the linear >> accelerator core. This can be minimized by using >> superconducting electromagnets, but there will always be >> inefficiencies. Assuming that we can get 99% efficiency >> out of superconductors, (not unreasonable) that means we >> will have to deal with 1 E16 watts of thermal energy. >> _BUT_ >> This will be spread out over the length of the entire core. >> also, we are going to have to raise the temp of the >> reaction mass from near Zero (kelvin) in the case of >> Hydrogen, to something approaching room temp >> -- (the reaction mass would then also serve to cool the >> superconductors) >> This heat, rather than the anntenna heat would probably be >> best suited to heating the living quarters. Kevin, the heat your talking about is enough to provide for all the electricity for a few thousand cities the size of Chicago! Thats the kind of power that keeps all those cities outside air temp a few degrees above country temps. You can't just brush that off by saying the engine will be a few klicks long and were can pump a lot of heat into the reaction mass. (Frankly I doubt the reaction mass can absorb that kind of heat load.) This is a lot of power, and we need to know what were going to do with it or the ship will cook itself alive. Kelly From popserver Sun Nov 12 06:55:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2171" "Sat" "11" "November" "1995" "22:12:41" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "52" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA14016; Sat, 11 Nov 95 19:14:20 PST Received: by mail04.mail.aol.com (8.6.12/8.6.12) id WAA28603; Sat, 11 Nov 1995 22:12:41 -0500 Message-Id: <951111221240_104196975@mail04.mail.aol.com> X-UIDL: 816159261.003 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, bpvanstr@yoho.uwaterloo.ca Subject: Re: Engineering Newsletter Date: Sat, 11 Nov 1995 22:12:41 -0500 >> Subject : Photon energy >> ReplyTo : Kevin >> ReplyFrom: Timothy >no, I am talking about the momentum of the photons as opposed to the >momentum of the ions the "Asimov" will eject as exhaust. Those will be >Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how >much energy you can invest) C at these speeds, a small mass flow is >sufficient to slow us down (or speed us up depending on which phase of >the mission we are in) at a constant 1 G. >> This was clear to me, but rethinking this made me >> realize that your method can't work. Because adding >> momentum to the Asimov will only make it move >> faster. Transforming it to reverse momentum would >> surely break one of the basic physic laws. No Tim. The momentum of the microwave is simply added load on the antena support structure (which is an extreamly unlikely structure) assuming it can take the load the power (electric) them feeds the engines which use it to produce forward or backward thrust. No violation of conservation of momentum. As long as the engine is powerful enough (and antenna strong enough) to overcome the thrust load of the photon sail effect of the big antenna. Every thing is fine. >> Subject : Solar array >> ReplyTo : Kevin >> ReplyFrom: Timothy >> But it won't reduce the total solar array, which is really big: >> Total Solar Power : 4E26 Watts >> Area of a globe with radius 1E9 metres : 7.9E17 square >> metres >> -> Solar power per square metre : 5E8 Watt >> Mean amount of power needed by the Asimov : 1E18 Watt >> -> Size of solar array : 1E18/5E8 = 2E9 square metres >> = disc with radius 2.5E4 metres. >> Remember 1E9 metres is quite near Sol. You wouldn't like >> to be there in your space suit, because 5E8 Joules would >> be added to your body temperature every second. Are you talking about a 5 kilometer disk a million kilometers from the suns surface? Does this not strike you as a servicing problem? Solar Power Density out here by earth is 1.35 KW/m^2 not the 5E8 Watt/m^2, but the equipment will be a lot more likely to keep working. Kelly Starks From popserver Mon Nov 13 05:58:00 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6302" "Mon" "13" "November" "1995" "01:18:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "138" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA26965; Sun, 12 Nov 95 16:18:26 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA07137 (5.67b/IDA-1.5 for ); Mon, 13 Nov 1995 01:18:54 +0100 Message-Id: <199511130018.AA07137@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 816242187.022 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Mon, 13 Nov 1995 01:18:59 +0100 ReplyFrom: Timothy Subject : LIT >BTW, has anyone kept all copies of the Mini-LIT newsletter to put in the >archives? I must admit I have not. I did, if some one needs it, ask... ReplyTo : Kelly ReplyFrom: Timothy Subject : Drawings About the drawing: where did you plan the shielding. And does it ride along with the hab ring, thus at 1 g? I had in mind that we made a shielding tube in which the hab-sections rotated. So then the shielding would not move and would not create an extra outward stress-factor. >>> What program did you use. > >RayDream designer 3. They were selling it for $100 bucks in MacWarehouse and >such a while back. So I picked it up. Won't run on the old Macintosh Plus I >have at home, but it runs like a bat out of hell on the new power Mac I have >at the office. I figured it would encourage me to get a new computer faster. If any one else likes doing raytraces, you can get PovRay or Radiance for FREE on the internet. I use PovRay and can make the same kinds of drawings. These are well know raytracers and work great. These programs are available for different platforms. (Tip: jpeg images would be about 4 times smaller, so would mean a less bytes with almost the same image quality) >Far larger than that. A multi generation ship would be technically far >harder then a fast relatavistic ship. To have half a chance it would need to >be compleatly self contained and self sufficent. With enough fuel and >resources for decades to centuries. Say a couple times the size of Manhattan >and with a population of hundreds of thousands of people. All that assuming >a big jump in technology to support it all with a crew that small. Indeed the ship itself would probably bigger than a rel. ship but, I don't think that energy will be a problem. The amounts of energy needed for a rel. ship are far more. It's quite easy to calculate the amount of energy that is needed for a self sustaining system. On Earth the energy income is 1400 Watts per square metre. With that energy all plants and animals seems to do well. Now the question is how much space per person is needed. Say 10000 square metres? That makes 4.4E14 Watts per person per year. The rel. ship engine would use 1000 times more per second. So now the only problem is to build that large ship. Material from astroids would probably be the main source. At the outer part of our solar system there seem to be billions of them in all the sizes you want. Making a self sufficient system should not be that hard with enough energy available. ReplyFrom: Timothy ReplyTo : Kevin and Kelly >>> _BUT_ >>> the conversion would take place on the antenna itself. >>> diodes wired directly onto the metal mesh would do the >>> power converting and the mesh (of special radiator fins >>> if need be) could radiate the heat. we have thousands and >>> thousands of square meters of antenna, it would serve as >>> an exceptional radiator. ---- > >I'll buy this part. With the hundreds to thousands of square kilometers of >mesh you've been taling about you have a lot of radiator space. Asuming you >can radiate the energy away fast enough to keep everything down to operating >temperature. If you want supper conductors this could be dicy. They like >cold temps and radiators like it very hot. I don't buy that part: Take 1 square kilometre or 1E6 square metres, that means 1E18/1E6=1E12 Watt per square metre. Take 10% of that and you get 1E11 Watts of lost energy per square metre. That sure would melt anything away. Even with thousands of square kilometres it is still too much. >Kevin, the heat your talking about is enough to provide for all the >electricity for a few thousand cities the size of Chicago! Thats the kind of >power that keeps all those cities outside air temp a few degrees above >country temps. You can't just brush that off by saying the engine will be a >few klicks long and were can pump a lot of heat into the reaction mass. > (Frankly I doubt the reaction mass can absorb that kind of heat load.) This >is a lot of power, and we need to know what were going to do with it or the >ship will cook itself alive. I agree. Also super conducting wires don't like very heavy currents. Subject : Photon energy ReplyTo : Kelly ReplyFrom: Timothy >>no, I am talking about the momentum of the photons as opposed to the >>momentum of the ions the "Asimov" will eject as exhaust. Those will be >>Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how >>much energy you can invest) C at these speeds, a small mass flow is >>sufficient to slow us down (or speed us up depending on which phase of >>the mission we are in) at a constant 1 G. > >>> This was clear to me, but rethinking this made me >>> realize that your method can't work. Because adding >>> momentum to the Asimov will only make it move >>> faster. Transforming it to reverse momentum would >>> surely break one of the basic physic laws. > >No Tim. The momentum of the microwave is simply added load on the antena >support structure (which is an extreamly unlikely structure) assuming it can >take the load the power (electric) them feeds the engines which use it to >produce forward or backward thrust. No violation of conservation of >momentum. As long as the engine is powerful enough (and antenna strong >enough) to overcome the thrust load of the photon sail effect of the big >antenna. Every thing is fine. No, that's not what I meant. I think that the energy that is gained by receiving the photons is not enough to overcome the velocity gain that you get by receiving these photons. So a powerful engine doesn't work because there isn't enough fuel. Subject: Solar array ReplyTo : Kelly ReplyFrom: Timothy >Are you talking about a 5 kilometer disk a million kilometers from the suns >surface? Does this not strike you as a servicing problem? In fact I was talking about a 50 kilometre disc... >Solar Power Density out here by earth is 1.35 KW/m^2 not the 5E8 Watt/m^2, >but the equipment will be a lot more likely to keep working. I agree completely, but having it so near Earth means a much bigger array. 5E8/1.35E3=3.7E5 times bigger to be exact. That is about 1.5 times the surface of the Earth!!! That seems to be an even bigger problem :) From popserver Mon Nov 13 18:03:10 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7269" "Mon" "13" "November" "1995" "04:38:45" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "177" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA21414; Mon, 13 Nov 95 02:38:39 PST Received: by maroon.tc.umn.edu; Mon, 13 Nov 95 04:38:45 -0600 Reply-To: Kevin C Houston In-Reply-To: <199511102257.AA24464@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII X-UIDL: 816285714.005 From: Kevin C Houston Sender: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Mon, 13 Nov 1995 04:38:45 -0600 (CST) On Fri, 10 Nov 1995, Timothy van der Linden wrote: > ReplyTo : Kelly > ReplyFrom: Timothy > > >We seem to have talked oiurselves out of all the engine concepts? We can't > >launch fuel over interstellar distences. The MARS system seems to need > >impossibly large collector arrays, and eiather system would cook the ship. > > > >bummer. > > Cheer up Kelly, we will find a way, we can always make a multi-generation > ship, I guess. Subject : Photon energy ReplyTo : Timothy ReplyFrom: Kevin > > OK, I agree with you about the aiming and timing 'problem' I wrote you > about. But I think I found another problem, so read on. > > >> What matters is the energy:momentum ratio of the beamed power. > >> For the photons in the beam that ratio is: > >> > >> E:p = c:1 where c=3E8 > >> > >> For the Asimov moving at 0.7 c that ratio is: > >> > >> E:p = 0.4c:1 > >> > >> The beam needs to have about 1/0.4=2.5 times less momentum than the Asimov, > >> but that is still a lot, so I can't agree with you that the momentum of the > >> beam is neglectable. > > WARNING! > I made a mistake here, I forgot that the momentum of the Asimov increased > while it was receiving photons. So the best thing to do is forget the above. > That's good, because i didn't understand it anyway. > >no, I am talking about the momentum of the photons as opposed to the > >momentum of the ions the "Asimov" will eject as exhaust. Those will be > >Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how > >much energy you can invest) C at these speeds, a small mass flow is > >sufficient to slow us down (or speed us up depending on which phase of > >the mission we are in) at a constant 1 G. > > This was clear to me, but rethinking this made me realize that your method > can't work. Because adding momentum to the Asimov will only make it move > faster. Transforming it to reverse momentum would surely break one of the > basic physic laws. > Huh? We won't be "subtracting" momentum, We'll just be adding it in the direction opposite to our direction of travel... thus we slow down and no physical laws get broken in the process. That's why a linear accelerator is better than a sail, you can aim your exhaust out of either end. > In formulas: > > - You shoot some photons at the Asimov, that will give an energy Up=p*c > where p is the momentum of the photon. > - To accelerate a mass M to speed v to decelerate the Asimov, we need an > amount of energy Uk=M*c^2*(gamma-1). > - We use all the energy of the received photons for that acceleration, > so Up=Uk --> p*c=M*c^2(gamma-1) --> p=M*c*(gamma-1) > - Thus to accellerate a mass M to speed v we need to receive photons which > will add us a momentum of p=M*c*(gamma-1). > - But of course we can subtract some momentum that we created by shooting > that mass M away. That momentum equals to p=gamma*M*v. > - Now the problem arises because by receiving photons we gain more momentum > that we loose by shooting that mass M away. > In physics: gamma*M*v is always less than M*c*(gamma-1) > All these formulas have me confused, let me see if I can work this out using some real (made-up) numbers. assume E=1 E+19 Watts, mass of "Asimov" = 2.5 E+09 Kg, wavelength of beam = 21 cm. I think we both agree that during the accel phase, the momentum from the photons helps us accelerate. But you are saying that the momentum of the photons is more than the momentum of the exhaust stream during the decelleration phase. hmm. let's see... p=E/c therefore p=3.34 E+10 Kg m/s the "Asimov" masses at 2.5 E+09 so if p=m v then v=p/m and v, (the amount of velocity change) = 13.34 m/s so every second that the beam is on us, we get "pushed" toward T.C. at 13.34 m/s faster than we were before. now let's use that energy we absorbed (minus 20% for conversion losses, now E= 8 E+18) to accelerate some amount of material to allow us to slow down. to find out how much material (per second) we must eject, let's use the rocket equation first. the apparent mass Ma (as seen by the crew) of the exhaust is g * M /Ve * c where Ve is .9996 and g is 23.34 (10 m/s^2 for us, and 13.34 m/s^2 to counteract the photonic thrust) so Ma= 194.71 Kg/sec moving at .9996 of c. note that this is only 3.89 Kg out of the tanks so thus the rest mass of the exhaust is 3.89 Kg/sec. Now let's see how much energy it takes to accelerate 3.89 Kg to .9996 of c the energy will equal the kinetic energy of accelerating the mass to the required speed, plus the energy of the "mass increase" E=Ke + Re Ke=1/2 m v^2 = 1/2 *3.89* (.9996*c)^2 = 1.74 E+17 Re= m c^2 = (194.71 - 3.89) * c^2 = 1.71 E+19 total energy required = 1.73 E+19 But we only have 1 E+19 (8 E+18 after conversion losses) what if we slowed down at 5m/s^2 the rocket equation: g is 18.34 (10 m/s^2 for us, and 13.34 m/s^2 to counteract the photonic thrust) so Ma= 153.00 Kg/sec moving at .9996 of c. note that this is only 3.06 Kg out of the tanks so thus the rest mass of the exhaust is 3.06 Kg/sec. Now let's see how much energy it takes to accelerate 3.89 Kg to .9996 of c the energy will equal the kinetic energy of accelerating the mass to the required speed, plus the energy of the "mass increase" E=Ke + Re Ke=1/2 m v^2 = 1/2 *3.06* (.9996*c)^2 = 1.34 E+17 Re= m c^2 = (153.00 - 3.89) * c^2 = 1.34 E+19 Hardly any decrease at all. Okay, Okay, I see your point (finally). so we can speed up, but we can't slow down even using beamed power. unless we use a retro reflecting ring sail, and that seems like such a waste > > Subject : Solar array > ReplyTo : Kevin > ReplyFrom: Timothy > > >increasing the number of transmitters will: > >reduce the amount of photon thrust that each transmitter is subjected to. > >reduce the amount of solar array that each trnsmitter must have. > >reduce the amount of beam jitter (by averaging the errors, they are reduced) > >reduce the heat load of each transmitter. (the non-Sol side of the solar > > panels will make an excellent heat radiator) > >increase the total cost of the mission (hey, you don't get nothing for free) > > But it won't reduce the total solar array, which is really big: > > Total Solar Power : 4E26 Watts Not really all that much more than the power a 2.5 E+09 Kg ship needs to get up to lightspeed in a decent amount of time. I think the ship needs to go on a diet! > Area of a globe with radius 1E9 metres : 7.9E17 square metres > -> Solar power per square metre : 5E8 Watt > > Mean amount of power needed by the Asimov : 1E18 Watt > -> Size of solar array : 1E18/5E8 = 2E9 square metres > = disc with radius 2.5E4 metres. > or 1000 disks with radius of 25 metres (Okay, Okay, a little more than 25 meters, but you get the point.) > Remember 1E9 metres is quite near Sol. You wouldn't like to be there in your > space suit, because 5E8 Joules would be added to your body temperature every > second. No one would be there, the transmitters would be built near earth, and launched into close solar orbit. if one or another fails, you launch another one rather than try and fix it. Kevin From popserver Tue Nov 14 01:11:43 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["6004" "Mon" "13" "November" "1995" "19:14:11" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951113191409_21423872@mail06.mail.aol.com>" "147" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA04697; Mon, 13 Nov 95 16:16:39 PST Received: by mail06.mail.aol.com (8.6.12/8.6.12) id TAA17058; Mon, 13 Nov 1995 19:14:11 -0500 Message-Id: <951113191409_21423872@mail06.mail.aol.com> X-UIDL: 816311356.035 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Mon, 13 Nov 1995 19:14:11 -0500 to: rddesign@wolfenet.com To: KellySt@aol.com >>> Heat load on the asimov: > >> Kelly >> This is way outside of my knowledge but couldn't this heat >> be expelled like exhaust and added to the thrust? Heat is >> just hot particles, isn't it? No such luck. Heat is eiather the thermal vibration of the molecules in an object, or infared radiation (life in a radiative heater). Can't think of how we'ld pump all the heat out of the ship fast enough to keep it cool. ReplyTo : Kelly ReplyFrom: Timothy Subject : Drawings >> About the drawing: where did you plan the shielding. And >> does it ride along with the hab ring, thus at 1 g? >> I had in mind that we made a shielding tube in which the >> hab-sections rotated. So then the shielding would not >> move and would not create an extra outward stress-factor. I was thinking of having the shielding in a fixed U shaped shielding trough that runs around the inside of the outer hull (the open end of the U points inward). If the shielding is made of steel instead of lead, the hab centrafuge tracks can run around on the top edges of the U. (of course the steel would be at least 3 feet thick!) >> (Tip: jpeg images would be about 4 times smaller, so would >> mean a less bytes with almost the same image quality) Now if Rick would get a JPEG viewer. ;) >Far larger than that. A multi generation ship would be technically far >harder then a fast relatavistic ship. To have half a chance it would need to >be compleatly self contained and self sufficent. With enough fuel and >resources for decades to centuries. Say a couple times the size of Manhattan >and with a population of hundreds of thousands of people. All that assuming >a big jump in technology to support it all with a crew that small. >> Indeed the ship itself would probably bigger than a rel. ship but, I don't >> think that energy will be a problem. The amounts of energy needed for a rel. >> ship are far more. ---- 4.4E14 Watts per person per year. The rel. ship >> engine would use 1000 times more per second. Of course instead of a 5 year (ship time) trip, your talking about centuries to thousands of years, and a crew 10-1000 times larger, and a proportianatly larger ship, etc... You might make an energy savings, but it wouldn't be as dramatic as you might expect. >> So now the only problem is to build that large ship. Material >> from astroids --- Making a self sufficient system should >> not be that hard with enough energy available. Building things takes skills, tools, and materials, as well as power. Of course we didn't give the ship tremendous power reserves. ReplyFrom: Timothy ReplyTo : Kevin and Kelly >>> _BUT_ >>> the conversion would take place on the antenna itself. >>> diodes wired directly onto the metal mesh would do the >>> power converting and the mesh (of special radiator fins >>> if need be) could radiate the heat. we have thousands and >>> thousands of square meters of antenna, it would serve as >>> an exceptional radiator. ---- > >I'll buy this part. With the hundreds to thousands of square kilometers of >mesh you've been taling about you have a lot of radiator space. Asuming you >can radiate the energy away fast enough to keep everything down to operating >temperature. If you want supper conductors this could be dicy. They like >cold temps and radiators like it very hot. >> I don't buy that part: Take 1 square kilometre or 1E6 square metres, that >> means 1E18/1E6=1E12 Watt per square metre. Take 10% of that and you get 1E11 >> Watts of lost energy per square metre. That sure would melt anything away. >> Even with thousands of square kilometres it is still too much. Good point. Subject : Photon energy ReplyTo : Kelly ReplyFrom: Timothy >>no, I am talking about the momentum of the photons as opposed to the >>momentum of the ions the "Asimov" will eject as exhaust. Those will be >>Hydrogen ions or maybe Xenon moving at .9996 or (.99996, depending on how >>much energy you can invest) C at these speeds, a small mass flow is >>sufficient to slow us down (or speed us up depending on which phase of >>the mission we are in) at a constant 1 G. > >>> This was clear to me, but rethinking this made me >>> realize that your method can't work. Because adding >>> momentum to the Asimov will only make it move >>> faster. Transforming it to reverse momentum would >>> surely break one of the basic physic laws. > >No Tim. The momentum of the microwave is simply added load on the antena >support structure (which is an extreamly unlikely structure) assuming it can >take the load the power (electric) them feeds the engines which use it to >produce forward or backward thrust. No violation of conservation of >momentum. As long as the engine is powerful enough (and antenna strong >enough) to overcome the thrust load of the photon sail effect of the big >antenna. Every thing is fine. >> >> No, that's not what I meant. I think that the energy that is gained by >> >> receiving the photons is not enough to overcome the velocity gain that you >> >> get by receiving these photons. So a powerful engine doesn't work because >> >> there isn't enough fuel. This can't be right. If it was no solar electric drive could ever work. Besides it sounds like you have a conservation of energy contradiction here. Subject: Solar array ReplyTo : Kelly ReplyFrom: Timothy >Are you talking about a 5 kilometer disk a million kilometers from the suns >surface? Does this not strike you as a servicing problem? In fact I was talking about a 50 kilometre disc... >Solar Power Density out here by earth is 1.35 KW/m^2 not the 5E8 Watt/m^2, >but the equipment will be a lot more likely to keep working. >> I agree completely, but having it so near Earth means a much bigger array. >> 5E8/1.35E3=3.7E5 times bigger to be exact. That is about 1.5 times the >> surface of the Earth!!! That seems to be an even bigger problem :) Ok, eiather system is infeasable. Kelly From popserver Tue Nov 14 01:58:01 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1318" "Mon" "13" "November" "1995" "17:53:32" "-0800" "Steve VanDevender" "stevev@efn.org" nil "32" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA10462; Mon, 13 Nov 95 17:52:43 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id RAA11645; Mon, 13 Nov 1995 17:53:32 -0800 Message-Id: <199511140153.RAA11645@tzadkiel.efn.org> In-Reply-To: <951113191409_21423872@mail06.mail.aol.com> References: <951113191409_21423872@mail06.mail.aol.com> X-UIDL: 816314212.001 From: Steve VanDevender To: KellySt@aol.com Cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Mon, 13 Nov 1995 17:53:32 -0800 KellySt@aol.com writes: > to: rddesign@wolfenet.com > To: KellySt@aol.com > > >>> Heat load on the asimov: > > > >> Kelly > >> This is way outside of my knowledge but couldn't this heat > >> be expelled like exhaust and added to the thrust? Heat is > >> just hot particles, isn't it? > > No such luck. Heat is eiather the thermal vibration of the molecules in an > object, or infared radiation (life in a radiative heater). Can't think of > how we'ld pump all the heat out of the ship fast enough to keep it cool. Heat is purely statistically random molecular motion. Infrared radiation is just a form of radiation that is good at inducing heat in common materials. Regarding this whole momentum-transfer issue, in some far-distant posting to the newsletter I pointed out that a reflective sail is the most efficient option for accelerating a spacecraft with beamed power; it changes photons with momentum +p into photons with momentum -p, and thereby increases the spacecraft momentum by 2p. It is unlikely that you could absorb the photons and use them to power a mass driver with greater efficiency than the reflectivity of a mirror. Using beamed power to decelerate a ship that's going in the same direction as the photons is more problematic. At best the efficiency is going to be bad. From popserver Wed Nov 15 03:51:19 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4909" "Tue" "14" "November" "1995" "21:09:22" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "139" "EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA29318; Tue, 14 Nov 95 19:09:19 PST Received: by maroon.tc.umn.edu; Tue, 14 Nov 95 21:09:23 -0600 In-Reply-To: <199511140153.RAA11645@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 816407391.009 From: Kevin C Houston To: Steve VanDevender Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl Subject: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-) Date: Tue, 14 Nov 1995 21:09:22 -0600 (CST) On Mon, 13 Nov 1995, Steve VanDevender wrote: > Regarding this whole momentum-transfer issue, in some far-distant > posting to the newsletter I pointed out that a reflective sail is > the most efficient option for accelerating a spacecraft with > beamed power; it changes photons with momentum +p into photons > with momentum -p, and thereby increases the spacecraft momentum > by 2p. It is unlikely that you could absorb the photons and use > them to power a mass driver with greater efficiency than the > reflectivity of a mirror. > Agreed. > Using beamed power to decelerate a ship that's going in the same > direction as the photons is more problematic. At best the > efficiency is going to be bad. > It is, which is why I proposed a linear accelerator in the first place. _BUT_ (drum roll please) I HAVE SOLVED THE PROBLEM OF SLOWING DOWN!!!! (Okay, Okay, I'll calm down now. And promise not to be so smug for the rest of this message) To Review: The main problem is that the momentum of the recieved photons is greater than the emitted exhaust. This is as it should be, the exhaust can't travel at C, and besides there's always losses. Solar electric space craft work because the ejected ion stream is traveling at far less than the speed of light, so the energy needed is less. and besides, the light is almost never coming from straight behind. But I digress. First, there is _no_ way to reduce the momentum imparted by the photons. However, we _can_ change the _direction_ of the thrust. or to paraphrase an old Chinese proverb. You can't change the direction of the wind, but you can adjust the sail. Do you see it yet? the solution? Tilted sail. Physical Design. (highly stylized ascii art) ////////// \\\\\\\\\\ <---- Sail elements |~~| | | <- ship Note: support cables omitted | | | | y | | ^ | | Energy is beamed from below in this | | | diagram. |--> x | | |__| The Sail (and it is a sail for most of the flight) is made of concentric conic sections tilted at 76.6 degrees (more on this later) this changes the direction of the imparted velocity, and since the sail elements have a circular symetry, the x componets of the force cancel out. A Force Balance on one sail element: Velocity y / <-- Sail element Vector\ component / \ | / \ | / \ | / \ | / \ | / x component_________\|/ / angle T (for theta) / / ________________________ There is another element on the other side of the ship whose x component cancels this one. The y component is Fy=F*cos (T) where F equals E/c. Some constants: c - Speed of Light (of course) = 3.0 E+08 m/s Ms - Mass of ship (RM neglected for now) = 2.5 E+09 Kg G - Ship's Gravity = 10 m/s^2 Ve - Exhaust velocity = .9996 c Eb - Beamed energy = 3.24 E+19 Watts Pe - Engine Thrust = 2 G T - angle of sail elements = 76.6 degrees (this value was found by trial) (and error and is critical ) Some equations: Photon Thrust(Newtons) Pp = E / c * cos (T) / Ms Pp=3.24E+19 / 3.0 E+08 * cos (76.6) / 2.5 E+09 = 10 m/s^2 Exhaust Mass (Kg/sec) Me = Pe * Ms / (Ve * c) Me = 20 * 2.5 E+09 / (0.9996 * 3 E+08) = 166.73 Kg/sec Exhaust Rest Mass (Kg/sec)Mr = Me * SQRT(1- Ve^2) Mr = 166.73 * Sqrt (1-0.9996^2) = 4.72 Kg/sec Kinetic Energy in Exhaust Ke = 1/2 * Mr * (Ve *c)^2 Ke = 1/2 * 4.72 * (0.9996 * 3 E+08) = 2.12 E+17 Relativistic Energy Er = (Me-Mr)*c^2 Er = (166.73 - 4.72) * 3 E+08^2 = 1.46 E+19 Total energy needed Et = Er + Ke Et = 2.12 E+17 + 1.46 E+19 = 1.48 E+19 Energy Available Ea = Eb * .8 (conversion losses) Ea = 3.24 E+19 * .8 = 1.66 E+19 And as you can see, the energy Available exceeds the energy needed. No physical laws get broken. During the Accel phase, the engines are quiet. The "Asimov" accelerates by reflected maser power (the transmitters operate at 1/2 power because the "Asimov" is Reflecting the maser, not Absorbing it like the above equations assume. This solution is more expensive (in terms of energy and sail area) it has a few extra benefits: the radial force component (x in the above force diagram) allows us to use tensile forces to hold the sail together (yes, it's a lot of force, but I think it is possible to do from an engineering standpoint) Kevin From popserver Wed Nov 15 14:33:27 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11732" "Wed" "15" "November" "1995" "15:22:36" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "276" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA27839; Wed, 15 Nov 95 06:22:11 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA06167 (5.67b/IDA-1.5 for ); Wed, 15 Nov 1995 15:22:20 +0100 Message-Id: <199511151422.AA06167@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=====================_816470556==_" X-Attachments: C:\RAY.GIF; X-UIDL: 816445922.005 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Wed, 15 Nov 1995 15:22:36 +0100 --=====================_816470556==_ Content-Type: text/plain; charset="us-ascii" The first part of this letter has been retarded a few days because of a bad working mail-demon... I added the newer part after the first two older messages. Subject : Photon energy ReplyTo : Timothy ReplyFrom: Kevin >All these formulas have me confused, let me see if I can work this out >using some real (made-up) numbers. assume E=1 E+19 Watts, mass of "Asimov" >= 2.5 E+09 Kg, wavelength of beam = 21 cm. >I think we both agree that during the accel phase, the momentum from the >photons helps us accelerate. But you are saying that the momentum of the >photons is more than the momentum of the exhaust stream during the >decelleration phase. hmm. let's see... > >p=E/c therefore p=3.34 E+10 Kg m/s the "Asimov" masses at 2.5 E+09 so >if p=m v then v=p/m and v, (the amount of velocity change) = 13.34 m/s so >every second that the beam is on us, we get "pushed" toward T.C. at 13.34 >m/s faster than we were before. > >now let's use that energy we absorbed (minus 20% for conversion losses, >now E= 8 E+18) to accelerate some amount of material to allow us to slow >down. to find out how much material (per second) we must eject, let's use >the rocket equation first. the apparent mass Ma (as seen by the crew) of the >exhaust is g * M /Ve * c where Ve is .9996 and g is 23.34 (10 m/s^2 for >us, and 13.34 m/s^2 to counteract the photonic thrust) so Ma= 194.71 Kg/sec >moving at .9996 of c. note that this is only 3.89 Kg out of the tanks so >thus the rest mass of the exhaust is 3.89 Kg/sec. > >Now let's see how much energy it takes to accelerate 3.89 Kg to .9996 of c >the energy will equal the kinetic energy of accelerating the mass to the >required speed, plus the energy of the "mass increase" E=Ke + Re >Ke=1/2 m v^2 = 1/2 *3.89* (.9996*c)^2 = 1.74 E+17 >Re= m c^2 = (194.71 - 3.89) * c^2 = 1.71 E+19 > >total energy required = 1.73 E+19 < Some text left out> >Okay, Okay, I see your point (finally). so we can speed up, but we can't >slow down even using beamed power. unless we use a retro reflecting ring >sail, and that seems like such a waste I'm happy to hear this. Unfortunately your conclusion was based on wrong calculations. I will explain here: You used: g * M /Ve * c but that formula is non relativistic. The right formula would be: g * M /(Ve * c * gamma) This gives the mass exhaust per second. That mass does not need to be translated to 'out of the tanks'-mass. After that you use a strange and wrong method to calculate the needed energy. The right formula for kinetic energy would be: E=m c^2 (gamma-1) (You don't need to create the rest energy, that part is already onboard the ship in the form of mass) So re-doing your first calculation: Take a=13.34 m/s^2 (this is the minimum to get even with the received photons) gamma=35.36 for v=0.9996c (gamma=1/SQRT(1-v^2/c^2) m/t=M a/(gamma Vexh) = 2.5E9 13.34/(35.36 0.9996 c) = 3.15 Kg needed E=m c^2 (gamma-1)=3.15 c^2 (35.36-1)= 9.73E18 So 1E19-9.73E18=2.7E17 Watt left over, that will give an acceleration of about 0.38 m/s^2 (This all assumes 100% efficiency) So I was not completely right saying it was impossible, but very efficient is it certainly not. I'm very happy that you tried to do the calculations, it makes it easier to find the difficulties. From my physics background I'm used to do more in formulas and less in numbers. Next time I will try to remember and use some numbers also. Subject : Solar array ReplyTo : Kevin ReplyFrom: Timothy >> But it won't reduce the total solar array, which is really big: >> >> Total Solar Power : 4E26 Watts > >Not really all that much more than the power a 2.5 E+09 Kg ship needs to >get up to lightspeed in a decent amount of time. I think the ship needs >to go on a diet! There is still a factor 1E5 involved. That is still much more, so a diet is not necessary and not possible if we want a relativistic ship. Meaning our ship could be 1E5 times heavier. >> Mean amount of power needed by the Asimov : 1E18 Watt >> -> Size of solar array : 1E18/5E8 = 2E9 square metres >> = disc with radius 2.5E4 metres. >> >or 1000 disks with radius of 25 metres (Okay, Okay, a little more than 25 >meters, but you get the point.) You mean 1.000.000 disks with radius of 25 metres! 1000 disks or 1 million disks that makes quite a difference. >> Remember 1E9 metres is quite near Sol. You wouldn't like to be there in your >> space suit, because 5E8 Joules would be added to your body temperature every >> second. > >No one would be there, the transmitters would be built near earth, and >launched into close solar orbit. if one or another fails, you launch >another one rather than try and fix it. I agree. But launching 1 million disks? Two other problems I could think of: - Any black spot on the solar array will probably melt away. - Each disk would be about 6 kilometres apart if they are in the same orbit. ------------------------------------------------------------------------------ NEWER PART ------------------------------------------------------------------------------ ReplyTo : Keving ReplyFrom: Timothy Subject : The bathtub is flowing over (EUREKA) >I HAVE SOLVED THE PROBLEM OF SLOWING DOWN!!!! First convince me... then celebrate... >First, there is _no_ way to reduce the momentum imparted by the photons. >However, we _can_ change the _direction_ of the thrust. NO and yes, you cannot change the initial size and direction of the photon thrust, but you can (of course) choose the direction of the thrust when transmitting a photon. In better words: You should see the reflection of a photon as two steps, independant of each other. The first step is receiving the photon where momenum to your mirror is added in the same direction as the photon CAME FROM. The second step is transmitting(reflecting) the photon, hereby is the momentum of the photon added in the opposite direction the photon GOES TO. So if you shoot a photon from the negative x direction to a mirror which is has 45 degree angle(on the x=y line) it first gets the momentum p in the x direction and second the momentum p in the y direction. This makes a total momentum of Sqrt(p^2+p^2)=Sqrt(2)*p in the xy direction. ^ | y | / | ______|/ | / +--- x / >Total energy needed Et = Er + Ke >Et = 2.12 E+17 + 1.46 E+19 = 1.48 E+19 > >Energy Available Ea = Eb * .8 (conversion losses) >Ea = 3.24 E+19 * .8 = 1.66 E+19 I think I know what you mean: (better formulas, see the previous message) Pp=10 m/s^2 Mr = Pe*Ms/(gamma Ve *c) = 20*2.5E9/(35.4 0.9996 3E8) = 4.72 Kg/sec Et = Me c^2(gamma-1) = 4.72 9E16 (35.4-1)=1.46E19 So, indeed much less than 3.24E19 But now how do you capture the photons? You are talking about mirrors (sail) all the time but not about capture. (I included a GIF-image of how I think you would do that) I still don't know why you used an angle of 76.6, doing the calculation with an angle of 85 degrees you need even less energy. My guess is that you forgot the capturing of the photons and therefore forgot to add momentum somewhere. You tried to trick the photons and thereby violated the preservation of momentum: If you receive an amount of photons, all their momentum is transferred to you. Once more, whatever ingenious construction you can think of, to receive a certain amount of photons and use their energy, you ALWAYS get ALL their momentum in the same direction as they went to. ReplyTo : Kelly ReplyFrom: Timothy Subject : Drawings >I was thinking of having the shielding in a fixed U shaped shielding trough >that runs around the inside of the outer hull (the open end of the U points >inward). If the shielding is made of steel instead of lead, the hab >centrafuge tracks can run around on the top edges of the U. (of course the >steel would be at least 3 feet thick!) That seems to be almost the same as what I wrote. OK. >>> (Tip: jpeg images would be about 4 times smaller, so would >>> mean a less bytes with almost the same image quality) > >Now if Rick would get a JPEG viewer. ;) I can't help with that, I don't know much about Mac-computers and their software. ReplyTo : Kelly ReplyFrom: Timothy Subject : Multi generation ship >Of course instead of a 5 year (ship time) trip, your talking about centuries >to thousands of years, and a crew 10-1000 times larger, and a proportianatly >larger ship, etc... You might make an energy savings, but it wouldn't be as >dramatic as you might expect. Hmm, yes you're right when using these numbers. But remember, my approach was VERY rough. In fact each human needs about 1.3E7 joules per day (=4.7E9 Joules per year). In the previous calculation I assumed Earth's biosphere balance. Which seems to be quite inefficient if it was designed only to keep people alive. Assuming Earth's biosphere and 100 square metres per person (which may be less) I calculated that every person used 4.4E14 Joule per year. So this means an efficiency of 0.001 % (My guess is that we could do far better that that.) >Building things takes skills, tools, and materials, as well as power. Of >course we didn't give the ship tremendous power reserves. The power needed to build the ship can probably be neglected with respect to the energy needed for the 1000 year trip. Materials should be mined at those asteroids. After the ship is build these mining-plant could be sold for much money if necessary. Tools could be made there or on Earth where ever it is cheapest. About the skills, I'm not sure. I guess working in space has to be common before we can build any interstellar ship. --=====================_816470556==_ Content-Type: application/mac-binhex40; name="RAY.GIF" Content-Disposition: attachment; filename="RAY.GIF" (This file must be converted with BinHex 4.0) :"e*"@5j(58B!3NP13@eNEh-!!!!!",-!!!!!lXP(58Bi0f(L!+X!J!!!!!!!rrr r,!!!!!$L!+X!!!,rM)qTbqd2SjbdfSZchVcl$iEL5*EQLCi!N!#flJZ(DdcApSh RqSkaFr",V&L+f6!)p"f&4q,"Z14*TmdSBVLSBJhDB2IkRBTcA56A#8ClNErYfHP 1MZHf0Y%X,k,e$IbD$NKf0mKAb)$hY*Hh'0J)BhGQ#1D!'-Q8k*Mj!XPSHGQRQ+M fTeQU3XKBpANB+YSdD4Sl`XRf#X[kS(SVbp[Vq`XF,$`-A%QXBA`XNLc-$!V5UY` TlB`,,Cd9M9e46D'pDCYQ&ICQjBNC'9lH[4lARKfU*Hk1,+ME[PAQkZi(4di13Gm qH[55h*2Ri4X+IYSiLGS&F9%F1h[@(+a)-BdNG2p[)RC3D-*CQ(iHTj'#Kp"J1*) Q&5%b8f[@$@B#@Ck,H&*2bS!Z8H'-Kl%N"j!!**+aR"JcQb&Ml1"TE,RaCY*PG@$ k4#H3!#168Ij!%8@jXPC2TEZDFUYkFD35JZT8KU@d-pGDUrIH344EX"jDKJLVYA8 Vm9YGRMc0fGADkHp3@@DTI2AeH%FEaT&j9HCaZH-fbCBR$0j-CSjK,R,cJXBXCM" 3dkG61kilYh&VcTMlXTkY+A24Z+0aPp)Y)qY@i,jV%%mSh&Ta4mFr*PpHc&jFk,q DEbKMR6VY[CqepmVHilRhld*FB!FrIQEj&)08b8j2jFT#I`IK3jBIFVLjprC$Nrr H$9Bmr6ALdRp8H480I`1bTiD"ehbd)#!0!J%0H1K&@1&rf9di$BD5q8$K8"`qiD& S)&l(B)QT'5AA*LSkeNFZ00$dSRNahQLFM$A@m3`1$Hh)BaDei3LNM9(j9d54,LC TST!!5V,(T)412PP#8-a&5D9-*2j@8CCDGRMPPPjq!%GeCBkC%*LaR)PQ250@&@+ E'5JSjCX[dKN)RPRD1D5FCmh'ji*kCK,SJ)-b9bKm*lCfU)Thi,DSRiFi#0UMNNk CU!k@AVTHR+HabDQRQ5)j+U5GISSITed#HUUF"E+DUTq[-SSPQJ,#'ZZBVC5UAUe l6STVUdmQD1U8[`*,+l,$re*5V,'AmKUNXT*#Qf1S1LCV,C'9CXYXX0`+Z`fefSN E!lR3QE[NYlk'UkkcQk&E(,`Yb0XXUZf#L`fphVjl,ll+0,UM[L%*r#R"XaJF,X" M+0&[1YXUl#')#+G*iF6%R'JaLL&Q(*fRe'c*F620KY`aYJf6$'($P2+VXXFXUic bBLh(V$(-pIC,XeiflpYZcR1fl$+l-ppmVmmp!'hd"8PhaV1k5rqjXmNi%pdce8j ErHh6hJ$YQpCFI`eff'+26AECCTq0GYTUV`fCef[M#6(ERKdAYp`4`1ffUR6RA54 !8,bNcR4ZBD3BA)$0-e8UKCrl$fmT6HHhi!L'pIJS!j,9E3TGQKRd81FhHFlj1@j %ERQ2PL4Zk&L*GE8+Q$CCGARTNb-PHRI8(@8P9)MYRT1D4mC1H%q,abZ@9+bAYD[ UUmpY1Q+p#89mjDXJ*IY@6bd[!92+lrllFRqMMTGKUZd%HrB*2YH2lGihP2YKmqM %81XYcKjrJ2eK2Jcqrr)0S0hqr`r!!!T`J!3XS!%2Q,B#Y!!lVcd!!!: --=====================_816470556==_-- From popserver Thu Nov 16 03:44:50 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3614" "Wed" "15" "November" "1995" "22:25:06" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "96" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA16952; Wed, 15 Nov 95 19:25:12 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id WAA11785; Wed, 15 Nov 1995 22:25:06 -0500 Message-Id: <951115222503_23751735@emout05.mail.aol.com> X-UIDL: 816493287.054 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com Subject: Re: Engineering Newsletter Date: Wed, 15 Nov 1995 22:25:06 -0500 ReplyTo : Keving ReplyFrom: Timothy Subject : The bathtub is flowing over (EUREKA) >I HAVE SOLVED THE PROBLEM OF SLOWING DOWN!!!! >> First convince me... then celebrate... >First, there is _no_ way to reduce the momentum imparted by the photons. >However, we _can_ change the _direction_ of the thrust. >> NO and yes, you cannot change the initial size and direction of the photon >> thrust, but you can (of course) choose the direction of the thrust when transmitting a photon. >> In better words: >> You should see the reflection of a photon as two steps, independant of each >> other. The first step is receiving the photon where >> momenum to your mirror is added >> in the same direction as the photon CAME FROM. >> The second step is transmitting(reflecting) the photon, hereby is the >> momentum of the photon added in the opposite direction the photon GOES TO. >> ----- Can't follow your argument, and the deleated graph seemed countradictory. I thing the fundemental part of kevins argument is correct. That the thrust vector on a photon sail is tangential to the surface of reflection, and the amount is related to the angle of incidence of reflection. (thats one of the standard solar sailing tricks.) If of course you absorb the photons in a rectena array the result is a bit less clear, but presumably you could reflect the energy off the sail to converters, at an angle that would cut down the forward thrust. The price of this would be a lot of extra thrust, and stress, on the guy wires. >> You tried to trick the photons and thereby violated the preservation of >> momentum: If you receive an amount of photons, all their momentum is >> transferred to you. Yes, but if it is transfered at an angle; part the momentum will be disapated in the structure, rather than acting to accelerate the ship. >> Once more, whatever ingenious construction you can think of, to receive a >> certain amount of photons and use their energy, you ALWAYS get ALL their >> momentum in the same direction as they went to. Define went to? ReplyTo : Kelly ReplyFrom: Timothy Subject : Drawings >>> (Tip: jpeg images would be about 4 times smaller, so would >>> mean a less bytes with almost the same image quality) > >Now if Rick would get a JPEG viewer. ;) >> I can't help with that, I don't know much about >> Mac-computers and their software. Huh?? Well as a hint you generally need to have a copy before you can use it. ReplyTo : Kelly ReplyFrom: Timothy Subject : Multi generation ship ----- >Building things takes skills, tools, and materials, as well as power. Of >course we didn't give the ship tremendous power reserves. >> The power needed to build the ship can probably be >> neglected with respect to the energy needed for the >> 1000 year trip. Materials should be mined at those >> asteroids. I wasn't talking about the energy to build the ship. I was talking about the energy, resources, and equipment needed to continually rebuild it in flight. Equipment has a life span too, and none if it will function for a thousand years. The ship will have to not only be equiped with its own internal ship yard, but with all the manufacturing facilities needed to build every part, and every tool in the complete ship. Then you have to bring along all the raw materials and fuel they'll need for the trip. Then you have to staff it with all the people with all the specialties needed to do all of that. The ship would need a degree of selfsuficency that no country, much less industrial country, on Earth has had in generations. Kelly From popserver Thu Nov 16 03:44:53 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2105" "Wed" "15" "November" "1995" "22:25:20" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "48" "Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA17002; Wed, 15 Nov 95 19:26:13 PST Received: by mail04.mail.aol.com (8.6.12/8.6.12) id WAA28195; Wed, 15 Nov 1995 22:25:20 -0500 Message-Id: <951115222515_23751943@mail04.mail.aol.com> X-UIDL: 816493287.055 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org Cc: rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, david@interworld.com Subject: Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-) Date: Wed, 15 Nov 1995 22:25:20 -0500 VERY NICE KEVIN!!! You delt with the structural and thrust problems at once! I'll call you later, but wanted to send a couple of ideas right away. I still have questions about momentum transfer vs power absorbsion. This neat conversion of absorbed power and momentum bothers me. I would think that converting the power would use up the energy that would generate the thrust. Maybe I'm confused? If the back side of the sail/collector was mirrored, and the frount side of the inner sail elements had the rectennas. Then durring the accel phase all sail elements can be trimed to reflect almost all the power straight back at Sol for max thrust. (Note you'll need a slight outward thrust to hold the sails out to the sides.) Durring the decel phase. The outer sails are trimed to reflect their energy inward toward frount of the inner sails. The inner sails are trimed to reflect the energy hiting their back inward toward other sails or dumping it. But this foward and outward thrust, serves to support them against backward and inward thrurst from the energy pouring inward and back from the outer sails onto the frount of the inner sails. The frount of the inner sails have the rectenna arrays. Which absorb and convert the microwaves. Good news. The sails have max reflectivity durring accel phase. Only the inner sail array needs the more complecated rectenna and power conversion/transmition/cooling equipment. (The outer segments are just wire mesh.) So servicing and costs can be minimized. Bad news The expensive power converters are going to be face first into the inter stellar medium, and they are going to be operating at much higher power densities. Cooling is going to be much harder. Weird thought. Am I right that microwaves can impart thier momentum on ions directly? Could you channel the power via waveguides, and feed the reaction mass into the power stream and get it to accelerate the plasma directly? I can't remenber it clearly, but I think their is some such mechanism. If so, you could avoid the heating problems of the power conversion step. Kelly From popserver Fri Nov 17 00:17:49 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5329" "Thu" "16" "November" "1995" "22:37:32" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "116" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA22866; Thu, 16 Nov 95 13:37:29 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA23535 (5.67b/IDA-1.5 for ); Thu, 16 Nov 1995 22:37:11 +0100 Message-Id: <199511162137.AA23535@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 816567351.020 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Thu, 16 Nov 1995 22:37:32 +0100 ReplyTo : Kelly ReplyFrom: Timothy Subject : The bathtub is flowing over (EUREKA) >>I HAVE SOLVED THE PROBLEM OF SLOWING DOWN!!!! > >>> First convince me... then celebrate... > >>First, there is _no_ way to reduce the momentum imparted by the photons. >>However, we _can_ change the _direction_ of the thrust. > >>> NO and yes, you cannot change the initial size and direction of the photon >>> thrust, but you can (of course) choose the direction of the thrust when >transmitting a photon. > >>> In better words: >>> You should see the reflection of a photon as two steps, independant of >each >>> other. The first step is receiving the photon where >>> momenum to your mirror is added >>> in the same direction as the photon CAME FROM. >>> The second step is transmitting(reflecting) the photon, hereby is the >>> momentum of the photon added in the opposite direction the photon GOES TO. >>> ----- > >Can't follow your argument, and the deleated graph seemed countradictory. I >thing the fundemental part of kevins argument is correct. That the thrust >vector on a photon sail is tangential to the surface of reflection, and the >amount is related to the angle of incidence of reflection. (thats one of the >standard solar sailing tricks.) Agreed, completely. But if you want to use all the photon's energy you have to stop them. Stopping them makes the ship go forward. Kevin tried to change the direction of the photons in a way that stopping them would not add to forward but sideward momentum. Doing the same thing for the other sideward momentum cancelled out the movement to either side. But as soon as you change the direction of a photon a little you get a small forward thrust. But if you want to change the direction so much to use Kevin's trick, then you have the same forward thrust as you would have if you captured the photons immediately. I referred to Kevin's trick. I'm still not completely sure if I understand Kevin's idea correctly since I don't know how and where he want to tap the photons' energy. >If of course you absorb the photons in a rectena array the result is a bit >less clear, but presumably you could reflect the energy off the sail to >converters, at an angle that would cut down the forward thrust. The price of >this would be a lot of extra thrust, and stress, on the guy wires. Reflecting the photons to another direction adds some forward momentum to the ship. And as soon as you stop the photons in the converters, you transfer the rest of the forward momentum of the photons! >>> You tried to trick the photons and thereby violated the preservation of >>> momentum: If you receive an amount of photons, all their momentum is >>> transferred to you. > >Yes, but if it is transfered at an angle; part the momentum will be disapated >in the structure, rather than acting to accelerate the ship. In that preservation also the direction is mentioned. So if before the absorption you have a forward momentum, than that momentum should be there after the absorption still in forward direction only now transferred to the ship. >>> Once more, whatever ingenious construction you can think of, to receive a >>> certain amount of photons and use their energy, you ALWAYS get ALL their >>> momentum in the same direction as they went to. > >Define went to? Went to = The direction of the photons before they encountered the Asimov. ReplyTo : Kelly ReplyFrom: Timothy Subject : Drawings >Huh?? Well as a hint you generally need to have a copy before you can use >it. I use an IBM-compatible computer and have programs to convert many image-formats. I assumed that for Mac computers there would be similar programs. ReplyTo : Kelly ReplyFrom: Timothy Subject : Multi generation ship >The ship would need a degree of selfsuficency that no country, much less >industrial country, on Earth has had in generations. Ah now I see what you mean. The industry on the ship would be completely different than that on Earth. The different production lines should be very generalized and not specialized. This means that one line can do all kinds of synthetic material moldings. Probably this results in a less efficient line. Not less efficient with energy but with time. My guess is that time is not the most important factor here. Another important thing would be automation of the production process. A lot of equipment would be made many times again, so then automation would ease the job. About specialties, of course it would be easier if we had specialist for everything but one person in a certain field can do a lot if he/she has the right information available. Again that would mean less efficient with time. But don't forget, on Earth lots of energy and manpower is used to innovate. The thing that we are concerned most about, is to keep what we have. Rebuilding what one has is a lot easier than creating new things. To keep up with Earth's technology we could simply copy what they had created. Furthermore almost all equipment should be recycled, a lot of energy can be spared if the equipment is designed for easy recycling. So this will and should reduce the need for raw materials a lot. Maybe we can recycle some of the energy if we enclose the ship with a kind of thermos flask and use heat exchangers to re-use some of that energy. From popserver Sun Nov 19 22:21:24 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["2933" "Sun" "19" "November" "1995" "16:14:37" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "65" "Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA12227; Sun, 19 Nov 95 14:13:51 PST Received: by maroon.tc.umn.edu; Sun, 19 Nov 95 16:14:37 -0600 In-Reply-To: <951115222515_23751943@mail04.mail.aol.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 816819575.000 From: Kevin C Houston To: KellySt@aol.com Cc: stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, david@interworld.com Subject: Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-) Date: Sun, 19 Nov 1995 16:14:37 -0600 (CST) On Wed, 15 Nov 1995 KellySt@aol.com wrote: > I still have questions about momentum transfer vs power absorbsion. This > neat conversion of absorbed power and momentum bothers me. I would think > that converting the power would use up the energy that would generate the > thrust. Maybe I'm confused? > Not at all, if you reflect, you get twice the momentum that you'd get if you absorbed. so there is no violation of energy conservation. > > > If the back side of the sail/collector was mirrored, and the frount side of > the inner sail elements had the rectennas. Then durring the accel phase > all sail elements can be trimed to reflect almost all the power straight > back at Sol for max thrust. (Note you'll need a slight outward thrust to > hold the sails out to the sides.) > > Durring the decel phase. The outer sails are trimed to reflect their > energy inward toward frount of the inner sails. The inner sails are trimed > to reflect the energy hiting their back inward toward other sails or > dumping it. But this foward and outward thrust, serves to support them > against backward and inward thrurst from the energy pouring inward and > back from the outer sails onto the frount of the inner sails. The frount > of the inner sails have the rectenna arrays. Which absorb and convert the > microwaves. > > Good news. > The sails have max reflectivity durring accel phase. > > Only the inner sail array needs the more complecated rectenna and power > conversion/transmition/cooling equipment. (The outer segments are just > wire mesh.) So servicing and costs can be minimized. > > Bad news > The expensive power converters are going to be face first into the inter > stellar medium, and they are going to be operating at much higher power > densities. Cooling is going to be much harder. > 1) about power converters (schottsky diodes) being face first into the "wind" we are going to need a lot of tension wires to keep the antenna from blowing apart, so if they were on the front, they would effectivly shield the diodes. 2) about cooling, angling the antennas requires more surface area, allowing for _smaller_ power densities, and more surface to radiate the heat. > > Weird thought. Am I right that microwaves can impart thier momentum on > ions directly? Could you channel the power via waveguides, and feed the > reaction mass into the power stream and get it to accelerate the plasma > directly? I can't remenber it clearly, but I think their is some such > mechanism. If so, you could avoid the heating problems of the power > conversion step. Agreed, this should be looked into. Not sure if this is possible with microwaves, I'm having difficulty seeing how the microwaves could be reflected into the reaction chamber without the inner sail elements getting in the way of the outer ones. but if it could be made to work, it would solve the heat problem neatly. From popserver Mon Nov 20 10:11:18 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3499" "Mon" "20" "November" "1995" "02:08:27" "-0800" "Steve VanDevender" "stevev@efn.org" nil "73" "Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA11205; Mon, 20 Nov 95 02:06:45 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id CAA01303; Mon, 20 Nov 1995 02:08:27 -0800 Message-Id: <199511201008.CAA01303@tzadkiel.efn.org> In-Reply-To: References: <951115222515_23751943@mail04.mail.aol.com> X-UIDL: 816862166.000 From: Steve VanDevender To: Kevin C Houston Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, david@interworld.com Subject: Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-) Date: Mon, 20 Nov 1995 02:08:27 -0800 Kevin C. Houston writes: > On Wed, 15 Nov 1995 KellySt@aol.com wrote: > > > I still have questions about momentum transfer vs power absorbsion. This > > neat conversion of absorbed power and momentum bothers me. I would think > > that converting the power would use up the energy that would generate the > > thrust. Maybe I'm confused? > > > > Not at all, if you reflect, you get twice the momentum that you'd get if > you absorbed. so there is no violation of energy conservation. This is not strictly true. In fact, I've been quite dubious of Kevin's claim that his configuration of solar sails would really produce deceleration. In fact, I believe that you can't use a static sail (that is, one permanently attached to the spacecraft) to decelerate, as to produce deceleration the reflected photon must increase in momentum to compensate for the spacecraft decreasing in momentum; the static sail is tied to the spacecraft so it cannot change its momentum separately from the spacecraft. The previously-mentioned "Dragonfly" sail (from Robert L. Forward's _Flight of the Dragonfly_) accomplishes deceleration by splitting the sail into a retro-reflecting portion that focuses energy back to the remaining portion of the sail attached to the spacecraft; in this case the retro-reflecting sail increases in momentum to compensate for the spacecraft's decrease in momentum, and thereby ends up carrying all of the momentum from the beamed power by the time the spacecraft has come to "rest". Consider a photon with momenergy [ p, p, 0 ] (that is, energy p, momentum p in the x direction, no momentum in the y direction), incident on a mirror with initial momenergy [ m, 0, 0 ] tilted at an angle theta, such that when theta = 0 the mirror reflects the photon straight back along its original path, and positive theta means counterclockwise rotation of the mirror. After reflection, the photon has momenergy [ p, -p * cos(2 * theta), -p * sin(2 * theta) ], and to conserve momenergy the mirror must then have momenergy [ m, p * (1 + cos(2 * theta)), p * sin(2 * theta) ]. (the total system momenergy remains [ m + p, p, 0 ]). You'll note that the expression (1 + cos(2 * theta)) is always greater than or equal to 0. In other words, the x-component of the mirror's momentum after reflection is always forward, or at best nil. So you can steer by tilting the sail, but you can't slow down. If you use multiple reflections, then you can analyze the behavior simply by considering the final photon momentum after the reflections. In the case of a double reflection that leaves the photons travelling in the same direction they originally were (maybe parallel to their original course) then there is _no_ net change in spacecraft momentum. If you change the direction of the photons, then you must _always_ leave them with a smaller x-component of momentum than they originally had, and this results in increased x-momentum for the spacecraft. You may be able to decrease the efficiency of the sails as much as you want, but you will never produce deceleration with multiple-reflection schemes as long as the sails are attached to the spacecraft and therefore tied to the spacecraft's momenergy. A really thorough treatment of multiple reflections would have to consider both the finite speed of light and the finite speed of propagation of changes in velocity through the spacecraft structure; for very high rates of acceleration these would be significant effects. From popserver Mon Nov 20 10:38:53 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4659" "Mon" "20" "November" "1995" "04:35:36" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "93" "Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA11737; Mon, 20 Nov 95 02:34:39 PST Received: by maroon.tc.umn.edu; Mon, 20 Nov 95 04:35:36 -0600 In-Reply-To: <199511201008.CAA01303@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 816863821.000 From: Kevin C Houston To: Steve VanDevender Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, david@interworld.com Subject: Re: EUREKA!!!!!!!!!! (ha ha ha ha ha ha) >:-) Date: Mon, 20 Nov 1995 04:35:36 -0600 (CST) On Mon, 20 Nov 1995, Steve VanDevender wrote: > Kevin C. Houston writes: > > > On Wed, 15 Nov 1995 KellySt@aol.com wrote: > > > > > I still have questions about momentum transfer vs power absorbsion. This > > > neat conversion of absorbed power and momentum bothers me. I would think > > > that converting the power would use up the energy that would generate the > > > thrust. Maybe I'm confused? > > > > > > > Not at all, if you reflect, you get twice the momentum that you'd get if > > you absorbed. so there is no violation of energy conservation. > > This is not strictly true. In fact, I've been quite dubious of > Kevin's claim that his configuration of solar sails would really > produce deceleration. In fact, I believe that you can't use a > static sail (that is, one permanently attached to the spacecraft) > to decelerate, as to produce deceleration the reflected photon > must increase in momentum to compensate for the spacecraft > decreasing in momentum; the static sail is tied to the spacecraft > so it cannot change its momentum separately from the spacecraft. > The previously-mentioned "Dragonfly" sail (from Robert L. > Forward's _Flight of the Dragonfly_) accomplishes deceleration by > splitting the sail into a retro-reflecting portion that focuses > energy back to the remaining portion of the sail attached to the > spacecraft; in this case the retro-reflecting sail increases in > momentum to compensate for the spacecraft's decrease in momentum, > and thereby ends up carrying all of the momentum from the beamed > power by the time the spacecraft has come to "rest". > > Consider a photon with momenergy [ p, p, 0 ] (that is, energy p, > momentum p in the x direction, no momentum in the y direction), > incident on a mirror with initial momenergy [ m, 0, 0 ] tilted at > an angle theta, such that when theta = 0 the mirror reflects the > photon straight back along its original path, and positive theta > means counterclockwise rotation of the mirror. After reflection, > the photon has momenergy > > [ p, -p * cos(2 * theta), -p * sin(2 * theta) ], > > and to conserve momenergy the mirror must then have momenergy > > [ m, p * (1 + cos(2 * theta)), p * sin(2 * theta) ]. > > (the total system momenergy remains [ m + p, p, 0 ]). > > You'll note that the expression (1 + cos(2 * theta)) is always > greater than or equal to 0. In other words, the x-component of > the mirror's momentum after reflection is always forward, or at > best nil. So you can steer by tilting the sail, but you can't > slow down. > > If you use multiple reflections, then you can analyze the > behavior simply by considering the final photon momentum after > the reflections. > > In the case of a double reflection that leaves the photons > travelling in the same direction they originally were (maybe > parallel to their original course) then there is _no_ net change > in spacecraft momentum. If you change the direction of the > photons, then you must _always_ leave them with a smaller > x-component of momentum than they originally had, and this > results in increased x-momentum for the spacecraft. You may be > able to decrease the efficiency of the sails as much as you want, > but you will never produce deceleration with multiple-reflection > schemes as long as the sails are attached to the spacecraft and > therefore tied to the spacecraft's momenergy. > > A really thorough treatment of multiple reflections would have to > consider both the finite speed of light and the finite speed of > propagation of changes in velocity through the spacecraft > structure; for very high rates of acceleration these would be > significant effects. > I think you have not completely understood my proposal. I am _not_ saying that the ship would slow down by this arrangement of sails, I'm only saying that the foreward momentum of the photons would be dumped into sideways momentum (which would then cancel out due to symetry) the photons would be absorbed and converted to electricity, then used to power a linear accelerator. All this rigamarole is to get around Timothy's valid objection that the foreward momentum of the recieved photons would exceed the momentum of the lineac if the antenna were not tilted. I readily admit that i lack the mathmatical tools to properly analyze this, I was hoping that someone else could do that part. But, The main point of the idea is valid, namely that by breaking up the sail/antenna into many conic sections, the foreward momentum of the absorbed photons can be dumped into the antenna's structure, and not into foreward acceleration of the "Asimov" From popserver Tue Nov 21 22:07:53 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9782" "Tue" "21" "November" "1995" "06:40:07" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "242" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA24233; Tue, 21 Nov 95 04:39:06 PST Received: by maroon.tc.umn.edu; Tue, 21 Nov 95 06:40:08 -0600 Reply-To: Kevin C Houston In-Reply-To: <199511151422.AA06167@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii X-UIDL: 816991539.006 From: Kevin C Houston Sender: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 21 Nov 1995 06:40:07 -0600 (CST) To: Timothy From: Kevin H. Subject: Various On Wed, 15 Nov 1995, Timothy van der Linden wrote: > Subject : Photon energy > ReplyTo : Timothy > ReplyFrom: Kevin > > >now let's use that energy we absorbed (minus 20% for conversion losses, > >now E= 8 E+18) to accelerate some amount of material to allow us to slow > >down. to find out how much material (per second) we must eject, let's use > >the rocket equation first. the apparent mass Ma (as seen by the crew) of the > >exhaust is g * M /Ve * c where Ve is .9996 and g is 23.34 (10 m/s^2 for > >us, and 13.34 m/s^2 to counteract the photonic thrust) so Ma= 194.71 Kg/sec > >moving at .9996 of c. note that this is only 3.89 Kg out of the tanks so > >thus the rest mass of the exhaust is 3.89 Kg/sec. > > > >Now let's see how much energy it takes to accelerate 3.89 Kg to .9996 of c > >the energy will equal the kinetic energy of accelerating the mass to the > >required speed, plus the energy of the "mass increase" E=Ke + Re > >Ke=1/2 m v^2 = 1/2 *3.89* (.9996*c)^2 = 1.74 E+17 > >Re= m c^2 = (194.71 - 3.89) * c^2 = 1.71 E+19 > > > >total energy required = 1.73 E+19 > > < Some text left out> > > >Okay, Okay, I see your point (finally). so we can speed up, but we can't > >slow down even using beamed power. unless we use a retro reflecting ring > >sail, and that seems like such a waste > > I'm happy to hear this. Unfortunately your conclusion was based on wrong > calculations. I will explain here: > > You used: g * M /Ve * c but that formula is non relativistic. The right > formula would be: g * M /(Ve * c * gamma) > This gives the mass exhaust per second. That mass does not need to be > translated to 'out of the tanks'-mass. But thats what I used, granted I did it in two steps, but multipling the result of g * M / (Ve *C) by SQRT(1-Ve^2/C^2) is the same as your formula > > After that you use a strange and wrong method to calculate the needed energy. > The right formula for kinetic energy would be: E=m c^2 (gamma-1) > (You don't need to create the rest energy, that part is already onboard the > ship in the form of mass) > No, I'm not creating rest energy, I'm creating the relativistic energy. my energy formula (which may well be wrong) was broken into two parts: 1) a non-relativistic KE formula for getting the rest mass up to Ve KE=1/2 m (Ve*C)^2 2) a way to account for apparent mass increase (sorry steve, I know that grates on you, but it don't make sense to me any other way) by using E=mc^2 and may I point out that my answers were within 5% of the "correct" answers. not bad for a first guess. However, I will in the future use: KE=M * C^2 * (gamma - 1) where gamma=1/SQRT(1-Ve^2) Note, in my formulas Ve is expressed as a fraction of C anyway, so I don't have to divide by C^2 > Subject : The bathtub is flowing over (EUREKA) > > > >First, there is _no_ way to reduce the momentum imparted by the photons. > >However, we _can_ change the _direction_ of the thrust. > > NO and yes, you cannot change the initial size and direction of the photon > thrust, but you can (of course) choose the direction of the thrust when > transmitting a photon. > > In better words: > You should see the reflection of a photon as two steps, independant of each > other. > The first step is receiving the photon where momenum to your mirror is added > in the same direction as the photon CAME FROM. > The second step is transmitting(reflecting) the photon, hereby is the > momentum of the photon added in the opposite direction the photon GOES TO. > So if you shoot a photon from the negative x direction to a mirror which is > has 45 degree angle(on the x=y line) it first gets the momentum p in the x > direction and second the momentum p in the y direction. This makes a total > momentum of Sqrt(p^2+p^2)=Sqrt(2)*p in the xy direction. > > ^ > | y > | / | > ______|/ | > / +--- x > / > No, the momentum of absorbing the photon: cos (45) * p and the momentum of transmiting a photon: cos (45) * p adding them together would give you 2 cos(45)*p and since cos (45) = SQRT(2)/2, the total is: (drum roll please) Sqrt(2)*p Which of course is the same result as your formula, but for different reasons. and would not be the same for angles other than 45 Question: If a photon has a waveLENGTH of 21 cm, what's it's waveWIDTH? Hint: It ain't zero. > > > But now how do you capture the photons? You are talking about mirrors (sail) > all the time but not about capture. (I included a GIF-image of how I think > you would do that) No, _you_ keep talking mirrors all the time. I never once talked about reflecting the photons anywhere. BTW, I've never gotten one gif image to work. I can save 'em, and I can get them to my home machine, but when they get there, I get a "Not a vaild GIF file" when I try to display. And that includes a file that Kelly FTP'd me, so I know it's not my mail program. Maybe I'm just a lone IBM'er in a MAC group. any other IBM'ers here? Did you get the GIF's to work? let me know so's I can get working copies please. > I still don't know why you used an angle of 76.6, doing the calculation with > an angle of 85 degrees you need even less energy. Every time I worked out the formulas, (and I just did it with your equation for KE) I ended up with not enough energy if I used an angle of less than 76.6 degrees (photon thrust exceeds engine thrust) and too much left over energy if I used an angle much greater than 76.6 (engine thrust exceeds photon thrust) > You tried to trick the photons and thereby violated the preservation of > momentum: If you receive an amount of photons, all their momentum is > transferred to you. Yes, agreed. I received all of the photons Monmentum, but only cos(76.6) of it is in the direction of ships travel. > Once more, whatever ingenious construction you can think of, to receive a > certain amount of photons and use their energy, you ALWAYS get ALL their > momentum in the same direction as they went to. No, not true. Tilted surfaces receive all the momentum, but at an angle which is normal to backside of the surface. To : All From: Kevin Subject: Revised numbers using Timothy's Kinetic Energy formula: Velocity of exhaust: .99996 C (yes, this has changed also) gamma of exhaust 111.8045 Energy Beamed from Earth 2.08 E+19 Watts Energy after conversion 1.66 E+19 Watts (80% eff) angle of antenna: 76.6 cosine of angle : 0.360702 at this angle and energy, the photons impart a 10 m/s^2 foreward thrust so the ship's engine must impart a 20 m/s^2 backward's thrust. to accomplish this we need an exhaust rest mass of G*M/(Ve*C*gamma) which equals 1.49 Kg/sec out of the tanks getting this up to .99996 C will require M*C^2*(gamma-1) or 1.49E+19 Watts leaving 1.77 E+18 left over. more than enough energy to keep the crew alive. I'm still working on the heat balance, more when I finish To: All From: Kevin Re: Question on diodes (schottsky's) As you no doubt know, conversion from microwaves to elec power is achieved with diodes. I've been assuming that a diode on the antenna but not connected to a circuit is just sitting there, and the antenna will reflect. when the circuit is completed, the diode will convert the microwaves to elec with some heat left over, and the antenna wil absorb. is this correct? Kevin P.S. to Timothy: I can't speak for Steve, but yes, I do actually write these at 2:08 am or whatever time appears on the header. I often stay up late or get up early to write these. and of course, the time you see is the time I sent it, not the time I started, so you can subtract about two days for writing time ;) PPS to All: I heard a couple of good jokes: 1) How do a Mathamatician, a Physist, and an Engineer _prove_ all odd numbers are prime? The Mathamatician says: 3 is prime, 5 is prime, 7 is prime. That's three examples, the rest follows by induction. The Physicist says: 3 is prime, 5 is prime, 7 is prime, 9 is... experimental error, 11 is prime, 13 is prime .... The Engineer says: 3 is prime, 5 is prime, 7 is prime, 9 is close to being prime, and as we get into higher and higher numbers, the difference between the prime and non-prime portions is so small that it can be ignored. And the Technician says: 3 is prime, 5 is prime, 7 is prime, 9 is... Hey Joe, hand me hammer. second joke: The Mathamatician, Physicist, and Engineer were all at a conference (on prime numbers no less) and that night, a fire broke out in each room. The Engineer woke up, saw the fire, grabbed a bucket, and ran into the bathroom. he estimated the size of the fire, rate of spread and available oxygen, and drew that much water plus 10% to cover his errors. He ran back into the bedroom, poured 95% of the water onto the fire, checked that it was out, then poured the rest just to make sure, and went back to bed. The Physicist woke up, saw the fire, grabbed a bucket, and ran into the bathroom. he wrote down a few equations detailing the size of the fire, the rate of spread and the available oxygen, accounted for the ambient temperature and humidity of the air, as well as the heat of combustion of the materials that were burning, calculated the precise amount of water to put out the fire, drew that amount and ran back into the bedroom, poured the water on the fire, checked the results against the predicted results and went back to bed. The Mathamatician woke up, saw the fire, grabbed a bucket, and ran into the bathroom. he turned on the faucet, saw the water coming out. wrote down a few equations, proved a solution existed. and went back to bed. From popserver Tue Nov 21 22:08:52 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4889" "Tue" "21" "November" "1995" "21:31:53" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "131" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA19534; Tue, 21 Nov 95 12:31:28 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA00782 (5.67b/IDA-1.5 for ); Tue, 21 Nov 1995 21:31:46 +0100 Message-Id: <199511212031.AA00782@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 816991539.036 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 21 Nov 1995 21:31:53 +0100 ReplyFrom: Timothy ReplyTo : Kevin H. Subject : Sail >But thats what I used, granted I did it in two steps, but multipling the >result of g * M / (Ve *C) by SQRT(1-Ve^2/C^2) is the same as your formula Yes agreed, somehow I missed that. I derived the formula using relativistics from the start. It can be dangerous to use non-relativistic formulas and later subtitute relativistic ones! >However, I will in the future use: >KE=M * C^2 * (gamma - 1) >where >gamma=1/SQRT(1-Ve^2) Great, but I think Steve does not like them... :) >No, the momentum of absorbing the photon: cos (45) * p >and the momentum of transmiting a photon: cos (45) * p > >adding them together would give you 2 cos(45)*p >and since cos (45) = SQRT(2)/2, the total is: (drum roll please) > >Sqrt(2)*p > >Which of course is the same result as your formula, but for different >reasons. and would not be the same for angles other than 45 OK, let me rewrite this and tell me if you agree: incoming outgoing ray ray \ / \ / \ / a (\/ ------------------- mirror (sail?) || || \/ resulting momentum The ray reflects at an angle a, this gives the mirror a momentum of 2*p*SIN(a) where p the momentum of the incoming and outgoing photon (this assumes the mirror does not move). The (kinetic) energy gain of the mirror in this proces is 2*p*c*SIN(a) the other part of the energy of the photon is still in the outgoing ray. >Question: If a photon has a waveLENGTH of 21 cm, what's it's waveWIDTH? > >Hint: It ain't zero. waveWIDTH ? I've never heard of this, please explain this new phenomenon if relevant. >> But now how do you capture the photons? You are talking about mirrors (sail) >> all the time but not about capture. (I included a GIF-image of how I think >> you would do that) >No, _you_ keep talking mirrors all the time. I never once talked about >reflecting the photons anywhere. Then where is the conical section sail used for if it does not reflect? >BTW, I've never gotten one gif image to work. I can save 'em, and I can >get them to my home machine, but when they get there, I get a "Not a >vaild GIF file" when I try to display. And that includes a file that >Kelly FTP'd me, so I know it's not my mail program. Maybe I'm just a lone >IBM'er in a MAC group. any other IBM'ers here? Did you get the GIF's to >work? let me know so's I can get working copies please. It was a 2 color (1 bit) GIF image created with CorelDraw. Maybe that 1 bit thing is why it did not work. What image viewer do you use?. Anyway, I will put it on the web, use your web browser with the next URL: http://rugth10.th.rug.nl/~linden/ray.gif >> You tried to trick the photons and thereby violated the preservation of >> momentum: If you receive an amount of photons, all their momentum is >> transferred to you. > >Yes, agreed. I received all of the photons Monmentum, but only cos(76.6) >of it is in the direction of ships travel. I still think you forgot something, but also I still don't know how and where you receive the momentum. I think I don't understand the explaination in the first letter you wrote about this. >> Once more, whatever ingenious construction you can think of, to receive a >> certain amount of photons and use their energy, you ALWAYS get ALL their >> momentum in the same direction as they went to. > >No, not true. Tilted surfaces receive all the momentum, but at an angle >which is normal to backside of the surface. Ah, do I get it right if I think you mean that the sail absorbs the photons? And that you think that if the photons are absorbed at an angle the forward momentum is less than if the photons are absorbed perpendicular? If these last guesses are wrong please answer the lines above the last quotes. ReplyTo : Kevin ReplyFrom: Tim Subject : Question on diodes (schottsky's) >As you no doubt know, conversion from microwaves to elec power is >achieved with diodes. I only have a fague idea of how this works. A Skottky diode is just a fast diode, right? First of all do we really need direct current or can we make an alternating current work also? If you really create a direct current, how do you complete the current loop so that the antenna does not become positive or negative loaded. >I've been assuming that a diode on the antenna but >not connected to a circuit is just sitting there, and the antenna will >reflect. That's why I didn't get it the first time I guess. >When the circuit is completed, the diode will convert the >microwaves to elec with some heat left over, and the antenna wil absorb. >is this correct? When and why is the circuit completed? I know some things about electronics but how to use antennas to make a direct current from a wave. If someone is able to explain in an other way, I would be very happy. From popserver Wed Nov 22 01:11:49 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["4528" "Tue" "21" "November" "1995" "19:05:38" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "131" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA07314; Tue, 21 Nov 95 17:04:33 PST Received: by maroon.tc.umn.edu; Tue, 21 Nov 95 19:05:38 -0600 In-Reply-To: <199511212031.AA00782@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817002585.000 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 21 Nov 1995 19:05:38 -0600 (CST) To: Timothy From: Kevin > > >However, I will in the future use: > >KE=M * C^2 * (gamma - 1) > >where > >gamma=1/SQRT(1-Ve^2) > > Great, but I think Steve does not like them... :) arrgghh! will you two make up your mind! either figure it out, consult a prof. or a book or something. and when you do get it right, please tell me and I'll use that method. > > > >No, the momentum of absorbing the photon: cos (45) * p > >and the momentum of transmiting a photon: cos (45) * p > > > >adding them together would give you 2 cos(45)*p > >and since cos (45) = SQRT(2)/2, the total is: (drum roll please) > > > >Sqrt(2)*p > > > >Which of course is the same result as your formula, but for different > >reasons. and would not be the same for angles other than 45 > > OK, let me rewrite this and tell me if you agree: > > incoming outgoing > ray ray > \ / > \ / > \ / > a (\/ > ------------------- mirror (sail?) > || > || > \/ > resulting momentum > > The ray reflects at an angle a, this gives the mirror a momentum of > 2*p*SIN(a) where p the momentum of the incoming and outgoing photon (this > assumes the mirror does not move). > The (kinetic) energy gain of the mirror in this proces is 2*p*c*SIN(a) the > other part of the energy of the photon is still in the outgoing ray. > Okay, I see, it does give the same result for angles other than 45 degrees. but it's cos not sin. and now your drawing shows just what I'm saying... if the incoming ray (in your drawing) is from Sol, then the resulting momentum would not be in the direction of T.C. > >Question: If a photon has a waveLENGTH of 21 cm, what's it's waveWIDTH? > > > >Hint: It ain't zero. > > waveWIDTH ? I've never heard of this, please explain this new phenomenon if > relevant. > Not new at all, tbhe width of a EM wave is the same as it's length. That's why an absorbed photon gives a momentum normal to the absorbing surface. > >> But now how do you capture the photons? You are talking about mirrors (sail) > >> all the time but not about capture. (I included a GIF-image of how I think > >> you would do that) > > >No, _you_ keep talking mirrors all the time. I never once talked about > >reflecting the photons anywhere. > > Then where is the conical section sail used for if it does not reflect? > It reflects during the accel portion of the trip. During decell phase, the conical section is an antenna. and it absorbs. > >Yes, agreed. I received all of the photons Monmentum, but only cos(76.6) > >of it is in the direction of ships travel. > > I still think you forgot something, but also I still don't know how and > where you receive the momentum. I think I don't understand the explaination > in the first letter you wrote about this. > > Tilted surfaces receive all the momentum, but at an angle > >which is normal to backside of the surface. > > Ah, do I get it right if I think you mean that the sail absorbs the photons? > And that you think that if the photons are absorbed at an angle the forward > momentum is less than if the photons are absorbed perpendicular? Yes, That seems right. Let me try again. y (T.C.) ^ | | +---> x Note: the "real" thrust should be normal to the | surface, ascii graphics prevents this | (abs) means absorbed V -y (Sol) Exhaust /\ real +y-component || +y-component thrust | || | real \ | / / |~~| \ \ | /thrust \|/ / | | \ \|/ -x <-----/^(abs) / | C| \ (abs)^\------> +x component / | /a) | o| \ | \ component | | r| | | | e| | incoming incoming photon photon Also note, I've omitted cabling across the T.C. side and Soll side of the sail. This cabling mechanically transmitts the force from one side of the sail to the other. > > I only have a fague idea of how this works. A Skottky diode is just a fast ^^^^^ I'm not trying to flame you Tim, I think you meant "vague" and since you're not sure either, Let's wait to hear from someone who is. Kevin From popserver Wed Nov 22 01:32:02 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2706" "Tue" "21" "November" "1995" "17:28:52" "-0800" "Steve VanDevender" "stevev@efn.org" nil "73" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA08707; Tue, 21 Nov 95 17:26:54 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id RAA14622; Tue, 21 Nov 1995 17:28:52 -0800 Message-Id: <199511220128.RAA14622@tzadkiel.efn.org> In-Reply-To: References: <199511212031.AA00782@student.utwente.nl> X-UIDL: 817003798.000 From: Steve VanDevender To: Kevin C Houston Cc: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 21 Nov 1995 17:28:52 -0800 Kevin C. Houston writes: > To: Timothy > From: Kevin > > >However, I will in the future use: > > >KE=M * C^2 * (gamma - 1) > > >where > > >gamma=1/SQRT(1-Ve^2) > > > > Great, but I think Steve does not like them... :) > > arrgghh! will you two make up your mind! either figure it out, consult > a prof. or a book or something. and when you do get it right, please > tell me and I'll use that method. I say that "relativistic mass increase" is a misnomer and that you are better off treating mass as invariant. > > OK, let me rewrite this and tell me if you agree: > > > > incoming outgoing > > ray ray > > \ / > > \ / > > \ / > > a (\/ > > ------------------- mirror (sail?) > > || > > || > > \/ > > resulting momentum > > > > The ray reflects at an angle a, this gives the mirror a momentum of > > 2*p*SIN(a) where p the momentum of the incoming and outgoing photon (this > > assumes the mirror does not move). > > The (kinetic) energy gain of the mirror in this proces is 2*p*c*SIN(a) the > > other part of the energy of the photon is still in the outgoing ray. > > Okay, I see, it does give the same result for angles other than 45 degrees. > but it's cos not sin. Timothy uses a different convention for the angle than I did. His math is correct using his convention. I was measuring a relative to normal of the mirror plane rather than relative to the surface. > Not new at all, tbhe width of a EM wave is the same as it's length. Huh? Why is this even relevant? > That's why an absorbed photon gives a momentum normal to the absorbing > surface. BZZZT! Thank you for playing. A reflected photon transfers momentum to a reflector normal to the reflecting surface. An absorbed photon transfers momentum in the direction and magnitude of the the photon's original momentum. This is the only consistent way to preserve conservation of momentum in both cases. Fundamental principle of relativistic mechanics: The momenergy (vector quantity of energy and momentum of a system) is conserved within the system through all interactions of the system components. If an absorbed photon only transferred momentum normal to the surface of the absorber, then the final momentum total for the system (photon and absorber) would _decrease_. This can't be true. You can't even weasel out of it by saying the momentum goes into extra heat or energy or something; momentum and energy are tallied in separate components. The photon energy goes into raising the heat of the absorber. The momentum goes into changing the velocity of the absorber. From popserver Wed Nov 22 20:46:56 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["2976" "Wed" "22" "November" "1995" "18:18:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199511221718.AA11651@student.utwente.nl>" "81" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA19266; Wed, 22 Nov 95 09:17:30 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11651 (5.67b/IDA-1.5 for ); Wed, 22 Nov 1995 18:18:49 +0100 Message-Id: <199511221718.AA11651@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817073086.001 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Wed, 22 Nov 1995 18:18:59 +0100 ReplyTo : Steve and Kevin ReplyFrom: Timothy >I say that "relativistic mass increase" is a misnomer and that >you are better off treating mass as invariant. Both methods are valid to use. The difference is more a physical matter than a mathematical. I was used to working with the "wrong" formulas and Steve was used working with the "right" formulas. The so called "wrong" formulas look a bit more like the classic formulas so they may be easier to understand. Both methods are being taught at universities and both are valid. I've always looked at is as follows: When you move faster and faster, part of the energy is transformed into mass, the other part is used to get the extra momentum. Now I only wonder, does such a fast moving particle excert greater gravitation on a non-moving observer? Steve if the answer is yes, how do you explain that not using "relativistic mass increase"? >Timothy uses a different convention for the angle than I did. >His math is correct using his convention. I was measuring a >relative to normal of the mirror plane rather than relative to >the surface. Yeps, it seems I'm a bit odd, doing that. >A reflected photon transfers momentum to a reflector normal to >the reflecting surface. An absorbed photon transfers momentum in >the direction and magnitude of the the photon's original >momentum. This is the only consistent way to preserve >conservation of momentum in both cases. Yes, this is what I tried to explain from the start, but due to misunderstandings I was not able to get to the point earlier. >Fundamental principle of relativistic mechanics: The momenergy >(vector quantity of energy and momentum of a system) is conserved >within the system through all interactions of the system >components. Or as I wrote earlier: Once more, whatever ingenious construction you can think of, to receive a certain amount of photons and use their energy, you ALWAYS get ALL their momentum in the same direction as they went to. ReplyTo : Kevin ReplyFrom: Timothy Here are some answers to the remaining part of your letter: >> Ah, do I get it right if I think you mean that the sail absorbs the photons? >> And that you think that if the photons are absorbed at an angle the forward >> momentum is less than if the photons are absorbed perpendicular? > >Yes, That seems right. Let me try again. So I finally understand... (Now I wonder how you turn a perfectly reflecting sail in an perfect absorber) >> I only have a fague idea of how this works. A Skottky diode is just a fast > ^^^^^ >I'm not trying to flame you Tim, I think you meant "vague" >and since you're not sure either, Let's wait to hear from someone who is. I don't mind people telling me how to write better English. Since it is not my native language I'm almost certain to be doomed to make mistakes. To: Ric Hedman Writing long mails is OK, but to write 4 lines and quote the other 250 lines seems a bit too much. Timothy From popserver Sat Nov 25 06:44:05 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["5191" "Fri" "24" "November" "1995" "21:05:06" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951124210503_115665323@emout04.mail.aol.com>" "121" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA18135; Fri, 24 Nov 95 18:05:09 PST Received: by emout04.mail.aol.com (8.6.12/8.6.12) id VAA07186; Fri, 24 Nov 1995 21:05:06 -0500 Message-Id: <951124210503_115665323@emout04.mail.aol.com> X-UIDL: 817281638.011 From: KellySt@aol.com To: stevev@efn.org, hous0042@maroon.tc.umn.edu Cc: T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu Subject: Re: Engineering Newsletter Date: Fri, 24 Nov 1995 21:05:06 -0500 >> A reflected photon transfers momentum to a reflector normal to >> the reflecting surface. An absorbed photon transfers >> momentum in the direction and magnitude of the the >> photon's original momentum. This is the only consistent >> way to preserve conservation of momentum in both cases. --- >> If an absorbed photon only transferred momentum normal >> to the surface of the absorber, then the final momentum >> total for the system (photon and absorber) would >> _decrease_. This can't be true. You can't even weasel >> out of it by saying the momentum goes into extra heat >> or energy or something; momentum and energy >> are tallied in separate components. The photon energy >> goes into raising the heat of the absorber. The momentum >> goes into changing the velocity of the absorber. The papers I've seen on on solar sails seem to disagree with you. RThey propose angling the sial to alter the thrust vector. Which would be impossible if the momenum transfer was always in the direction of the photons origional vector. Come to think of it all solar sailing would be impossible, since the purpose is alway to add or subtract velocity perpendicular to the solar light vector. Also it would be rather strange given thatthe photon has changed its course and mometum vector to one crossing the ship and beam vectors. Since its new course has an added lateral vector, there must have been a coresponding lateral vector componenect in the reflection of the sail. I have a lot of problem bying the idea that the light bouncing off a sail doesn't lose energy proportional to the kinetic or heat energy gain of the ship. Th power has to be coming from somewhere. > > On Wed, 15 Nov 1995 KellySt@aol.com wrote: > > > > > I still have questions about momentum transfer vs power absorbsion. This > > > neat conversion of absorbed power and momentum bothers me. I would think > > > that converting the power would use up the energy that would generate the > > > thrust. Maybe I'm confused? > > > > > > > Not at all, if you reflect, you get twice the momentum that you'd get if > > you absorbed. so there is no violation of energy conservation. This implies that the power of the beam is half the momentum of the beam. But if the beam is reflected, and gives up twice the momenum, it would have exausted all its power. If its then reflected again, it would lose more. This doesn't work. So: What percentage of the beam energy is lost in a reflection? (If this % is small, the the remainder might be enough to power the ships drive.) KS >> Durring the decel phase. The outer sails are trimed to reflect their KS >> energy inward toward frount of the inner sails. The inner sails are trimed KS >> to reflect the energy hiting their back inward toward other sails or KS >> dumping it. But this foward and outward thrust, serves to support them KS >> against backward and inward thrurst from the energy pouring inward and KS >> back from the outer sails onto the frount of the inner sails. The frount KS >> of the inner sails have the rectenna arrays. Which absorb and convert the KS >> microwaves. > KS >> Good news. KS >> The sails have max reflectivity durring accel phase. > KS >> Only the inner sail array needs the more complecated rectenna and power KS >> conversion/transmition/cooling equipment. (The outer segments are just KS >> wire mesh.) So servicing and costs can be minimized. > KS >> Bad news KS >> The expensive power converters are going to be face first into the inter KS >> stellar medium, and they are going to be operating at much higher power KS >> densities. Cooling is going to be much harder. > >1) about power converters (schottsky diodes) being > face first into the "wind" we are going to need a lot of > tension wires to keep the antenna from blowing apart, so >if they were on the front, they would effectivly shield the diodes. Not unless the wires became a wall. > 2) about cooling, angling the antennas requires more surface > area, allowing for _smaller_ power densities, and more > surface to radiate the heat. But if you reflect the beam inward, it will be concentrated to far higher power levels. The angle and demensions of the antenna isn't important. only the power density on the converter array. > KS >> Weird thought. Am I right that microwaves can impart thier momentum on KS >> ions directly? Could you channel the power via waveguides, and feed the KS >> reaction mass into the power stream and get it to accelerate the plasma KS >> directly? I can't remenber it clearly, but I think their is some such KS >> mechanism. If so, you could avoid the heating problems of the power KS >> conversion step. > Agreed, this should be looked into. Not sure if this is possible with > microwaves, I'm having difficulty seeing how the microwaves could be > reflected into the reaction chamber without the inner sail elements > getting in the way of the outer ones. but if it could be made to work, > it would solve the heat problem neatly. The sails could be kept out of the way. Also the use of waveguides would be usefull for the inner systems. Kelly Starks From popserver Sat Nov 25 07:49:53 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5251" "Fri" "24" "November" "1995" "23:47:54" "-0800" "Steve VanDevender" "stevev@efn.org" nil "107" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA27800; Fri, 24 Nov 95 23:45:00 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id XAA05957; Fri, 24 Nov 1995 23:47:54 -0800 Message-Id: <199511250747.XAA05957@tzadkiel.efn.org> In-Reply-To: <951124210503_115665323@emout04.mail.aol.com> References: <951124210503_115665323@emout04.mail.aol.com> X-UIDL: 817285608.000 From: Steve VanDevender To: KellySt@aol.com Cc: stevev@efn.org, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu Subject: Re: Engineering Newsletter Date: Fri, 24 Nov 1995 23:47:54 -0800 KellySt@aol.com writes: > The papers I've seen on on solar sails seem to disagree with > you. RThey propose angling the sial to alter the thrust > vector. Which would be impossible if the momenum transfer was > always in the direction of the photons origional vector. You don't seem to have read what I wrote, so I'll repeat it below. > >> A reflected photon transfers momentum to a reflector normal to > >> the reflecting surface. This in no way contradicts your understanding. If you tilt a sail, you get a sideways thrust on the sail. The momentum transfer is in the direction against the normal (the perpendicular to the surface) of the sail. However, absorbing a photon is different. In this case conservation of momentum requires that all of the photon's momentum and energy be transferred into the absorbing object. What I was objecting to earlier was Kevin's bald assertion that an absorbed photon adds momentum only relative to the normal of the absorbing surface, apparently because he did not properly analyze the behavior of reflection. You can think of reflection as a two-step process: absorption and re-emission. Momentum is transferred equally (as required by conservation of momentum) in each step. Kevin's mistake seemed to be in his calculation of the quantity of momentum transferred in each step, based on the total momentum transferred between the time before absorption and after re-emission. When a photon is absorbed, all of its energy is transferred into the absorber, and all of its momentum (not just some, as Kevin thought). If the photon was absorbed by a reflector, then it is instantly re-emitted, and the emitted photon has the same magnitude of energy and momentum as the original, but the momentum is in a different direction, and the reflector gets a new momentum component to compensate. The vector sum of the photon momenta before and after the reflection is the negative of the momentum transferred to the reflector, but the momentum transfer in each stage is not just half of this resultant vector. For an instant, the reflector speeds up the same way it would if it was never planning to re-emit the photon; an instant later it is accelerated in the direction opposite the emitted photon. > Come to think of it all solar sailing would be impossible, > since the purpose is alway to add or subtract velocity > perpendicular to the solar light vector. Also it would be > rather strange given thatthe photon has changed its course and > mometum vector to one crossing the ship and beam vectors. > Since its new course has an added lateral vector, there must > have been a coresponding lateral vector componenect in the > reflection of the sail. Light sailing would be useless if you couldn't get velocity components in other directions, say to put yourself in an orbit. Fortunately light sails don't work the way you think they do. In fact, your statement here contradicts your statement above -- either tilted light sails produce sideways thrust or they don't. To get velocity away from the star in the direction of light emitted from the star, aim your light sail to reflect light directly back at the star. To get velocity towards the star, turn your light sail sideways or furl it completely, and let the star's gravity accelerate you. There isn't a way to use the sail to accelerate yourself towards the star any faster than the star's gravity would accelerate you, though. Tilt the sail, and you get an additional velocity component perpendicular to the light emitted from the star. You are right, even though you don't want to believe yourself. > I have a lot of problem bying the idea that the light bouncing > off a sail doesn't lose energy proportional to the kinetic or > heat energy gain of the ship. Th power has to be coming from > somewhere. If the sail is reflective to the incident photon, then the photon doesn't lose energy as a result of reflection. The ship changes velocity because the photon changes direction. That's where the "power" comes from. If you don't buy conservation of momentum and energy, you won't get very far in physics. Here's an interesting thought experiment that I don't remember posting to the Starship Design forum, but that some of you may have seen since I do remember mailing it to somebody. You have two optically flat perfectly reflective mirrors (purchased from the same physics supply store where you get frictionless surfaces and other gedankenexperiment supplies). You also have a very powerful laser capable of emitting a short but extremely bright laser pulse, with sufficient momentum that the pulse can accelerate these mirrors measurably. Set up the two mirrors parallel to each other and facing each other, such that light can reflect between the mirrors indefinitely. Place the laser between them, and have it emit a light pulse aimed to reflect between the two mirrors; remove the laser immediately so that the light does not strike it but instead reflects between the two mirrors. What happens to the mirrors? What happens to the light pulse? An answer describing the limit state of the mirrors and light pulse is acceptable; you don't have to perform a step-by-step analysis of each reflection. From popserver Sat Nov 25 09:05:26 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4055" "Sat" "25" "November" "1995" "01:02:48" "-0800" "Steve VanDevender" "stevev@efn.org" nil "83" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA00273; Sat, 25 Nov 95 00:59:52 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id BAA06131; Sat, 25 Nov 1995 01:02:48 -0800 Message-Id: <199511250902.BAA06131@tzadkiel.efn.org> In-Reply-To: <199511221718.AA11651@student.utwente.nl> References: <199511221718.AA11651@student.utwente.nl> X-UIDL: 817290141.000 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sat, 25 Nov 1995 01:02:48 -0800 Timothy van der Linden writes: > ReplyTo : Steve and Kevin > ReplyFrom: Timothy > > >I say that "relativistic mass increase" is a misnomer and that > >you are better off treating mass as invariant. > > Both methods are valid to use. The difference is more a physical matter than > a mathematical. I was used to working with the "wrong" formulas and Steve > was used working with the "right" formulas. > The so called "wrong" formulas look a bit more like the classic formulas so > they may be easier to understand. > > Both methods are being taught at universities and both are valid. I think we'd both agree that, for example, p(v) = m * v / sqrt(1 - v^2). What I have learned to be suspicious of is interpreting this as (m/sqrt(1 - v^2)) * v, as if the mass somehow increases with velocity. What I find to be a more intuitive and less misleading interpretation is that mass is invariant (m^2 = E^2 - p^2) but that energy and momentum can increase without limit as the moving object accelerates. When doing more elaborate kinematics problems it's also easier to just keep track of the conserved E and p components, then sort out the resultant masses of the reaction products. Often in math there is more than one way to the right answer. I happen to find that concentrating on conservation of energy and momentum and keeping track of invariant quantities makes it easier to get the right answer and to prove that it's right. If you can do it the "wrong" way, get the right answer, and prove that it's right, then fine. > I've always looked at is as follows: When you move faster and faster, part > of the energy is transformed into mass, the other part is used to get the > extra momentum. I used to look at it this way, but Taylor and Wheeler talked me out of it (see chapter 8 of _Spacetime Physics_ for a lengthy, careful discussion on "Use and Abuse of the Concept of Mass"). The problem here is that relative velocity or acceleration do not cause any fundamental changes in the structure of the moving object. Where is this extra mass? If it's really stashed on the ship somewhere then the people on the ship could measure it. But they don't feel the ship getting heavier or see any increase in the mass of the ship in their frame. You also seem to be falling into the same trap that Kelly did earlier, in not treating energy and momentum as separate components. Most of the counterintuitive results of relativistic kinematics problems come from failing to understand that the conserved quantity in a reaction is a _vector_ quantity, and that the magnitude of that vector is calculated using Lorentz rather than Euclidean geometry. Taylor and Wheeler's wisdom on the subject is that the definition of mass is sqrt(E^2 - p^2); then every observer sees the same mass for the same object, no matter what their relative motion. The quick treatment in many physics texts is that mass is sort of like E, but they do a lot of tapdancing to keep everything consistent. This appears to be motivated by trying explain the famous "E = m * c^2", which turns out to be a lot less profound an observation than some of the other implications of relativistic physics. Taylor and Wheeler look at "E = m * c^2" as a mere matter of unit conversion; it's only really true if you are at rest relative to the mass in question, and they consider the use of Lorentz geometry for spacetime and invariance of spacetime interval as more fundamental and revealing concepts. > Now I only wonder, does such a fast moving particle excert greater > gravitation on a non-moving observer? This I can't answer with certainty. Offhand, I'd say "no." If the particle's mass doesn't change, then how could its gravitation change? > Steve if the answer is yes, how do you explain that not using "relativistic > mass increase"? If, on the other hand, a moving object did exert greater gravitation than a stationary object of the same mass, I'd probably be looking for a relation to a quantity that did change, like the object's total energy. From popserver Sun Nov 26 00:47:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["471" "Sat" "25" "November" "1995" "16:30:23" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "19" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA19362; Sat, 25 Nov 95 14:28:51 PST Received: by maroon.tc.umn.edu; Sat, 25 Nov 95 16:30:23 -0600 In-Reply-To: <199511250902.BAA06131@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817346679.003 From: Kevin C Houston To: Steve VanDevender Cc: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 25 Nov 1995 16:30:23 -0600 (CST) To: all nitpickers From: A nit(wit) who is tired of getting picked on. ;) see my web page http://www.umn.edu/nlhome/m056/hous0042/asimov.html for an idea that is consistant with Steve and Timothy's objections. i.e. reflection transferrs momentum to the normal, and absorbtion transfers momentum in the direction of the photons original vector. Advance billing: it is _still_ possible to cancel the momentum within the structure of the antenna/sail . HA! Kevin From popserver Sun Nov 26 00:48:01 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["5281" "Sun" "26" "November" "1995" "00:51:51" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199511252351.AA19695@student.utwente.nl>" "125" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA21932; Sat, 25 Nov 95 15:49:42 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19695 (5.67b/IDA-1.5 for ); Sun, 26 Nov 1995 00:51:43 +0100 Message-Id: <199511252351.AA19695@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817346679.008 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sun, 26 Nov 1995 00:51:51 +0100 ReplyTo : Kevin and Kelly ReplyFrom : Timothy Subject : Infinite energy? > > I have a lot of problem bying the idea that the light bouncing > > off a sail doesn't lose energy proportional to the kinetic or > > heat energy gain of the ship. Th power has to be coming from > > somewhere. > >If the sail is reflective to the incident photon, then the photon >doesn't lose energy as a result of reflection. The ship changes >velocity because the photon changes direction. That's where the >"power" comes from. I think I can't agree with that Steve, when the photon enters the first stage of the reflection, i.e. absorption, it adds some momentum to the ship. So the velocity of the ship increases. Now we enter the second stage of reflection, re-transmission. Relative to the ship the outgoing wavelength of the photon is the same as the incoming photon (because of invariance). But the observer at rest sees that that transmitted photon has dopplershifted (nice verb) and thus lost some energy. This is the same principle the police uses to measure speeding cars with radar. >What happens to the mirrors? What happens to the light pulse? >An answer describing the limit state of the mirrors and light >pulse is acceptable; you don't have to perform a step-by-step >analysis of each reflection. Assuming these mirrors have mass, they indeed will get some velocity that correspondends to the same momentum as the photon. By each reflection the photon will loose some momentum and lower its wavelength. ReplyTo : Kelly ReplyFrom : Timothy >I agree that we are stuck without a new power source. Kevins microwave >system or my Externally fueled system are at best theoretical possibilities, >with no real credible way to build them. Externally fueled did that mean scooping? I'm not sure anymore, please tell me if my assumption is right. ReplyTo : Steve ReplyFrom: Timothy Subject : Relativistic mass increase >>>I say that "relativistic mass increase" is a misnomer and that >>>you are better off treating mass as invariant. >> I've always looked at is as follows: When you move faster and faster, part >> of the energy is transformed into mass, the other part is used to get the >> extra momentum. > >I used to look at it this way, but Taylor and Wheeler talked me >out of it (see chapter 8 of _Spacetime Physics_ for a lengthy, >careful discussion on "Use and Abuse of the Concept of Mass"). >The problem here is that relative velocity or acceleration do not >cause any fundamental changes in the structure of the moving >object. Where is this extra mass? If it's really stashed on the >ship somewhere then the people on the ship could measure it. But >they don't feel the ship getting heavier or see any increase in >the mass of the ship in their frame. I wrote it wrong the first time, indeed then the mass must be somewhere on the ship. But look at it this way: When an object starts moving it deforms space-time in such a way that the object looks heavier to the outside world and the other way around, i.e. the object "notices" the outside world to be heavier. This means that locally no mass increase is measured, for the same reason that locally no length contraction or time dilation is measured. >You also seem to be falling into the same trap that Kelly did >earlier, in not treating energy and momentum as separate >components. Most of the counterintuitive results of relativistic >kinematics problems come from failing to understand that the >conserved quantity in a reaction is a _vector_ quantity, and that >the magnitude of that vector is calculated using Lorentz rather >than Euclidean geometry. I still don't see the trap where I fell in. You say that I should treat momentum and energy as seperate components. But I don't see how/where I treated them as one quantity. >Taylor and Wheeler's wisdom on the subject is that the definition >of mass is sqrt(E^2 - p^2); then every observer sees the same >mass for the same object, no matter what their relative motion. How do you measure E and p? E seems to be relativistic mass and p relativistic momentum. (E=gamma*m_rest p=gamma*m_rest*v) I would measure the perceived relativistic mass and the relative velocity. As far as I can see, doing that all observers will also agree about the rest mass. >> Now I only wonder, does such a fast moving particle excert greater >> gravitation on a non-moving observer? > >This I can't answer with certainty. Offhand, I'd say "no." If >the particle's mass doesn't change, then how could its >gravitation change? I don't know the answer for certain either, but when making the link with length contraction and time dilation I would say that indeed a bigger mass is measured. >> Steve if the answer is yes, how do you explain that not using "relativistic >> mass increase"? > >If, on the other hand, a moving object did exert greater >gravitation than a stationary object of the same mass, I'd >probably be looking for a relation to a quantity that did change, >like the object's total energy. So that would mean that some of the change in energy is change of gravitational energy, from which I would conclude that it comes from extra mass (or bending of space time). Is it this translation of energy to mass that gives the trouble? From popserver Sun Nov 26 01:13:12 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1344" "Sat" "25" "November" "1995" "17:08:10" "-0800" "Steve VanDevender" "stevev@efn.org" nil "32" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA25004; Sat, 25 Nov 95 17:05:08 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id RAA08463; Sat, 25 Nov 1995 17:08:10 -0800 Message-Id: <199511260108.RAA08463@tzadkiel.efn.org> In-Reply-To: References: <199511250902.BAA06131@tzadkiel.efn.org> X-UIDL: 817348202.000 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , Timothy van der Linden , KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 25 Nov 1995 17:08:10 -0800 Kevin C. Houston writes: > To: all nitpickers > From: A nit(wit) who is tired of getting picked on. ;) Sorry, but conservation of energy and momentum are too fundamental to ignore. If you can't follow those rules then you may as well give up and design a warp drive, since you're throwing out the laws of physics anyway. > see my web page > http://www.umn.edu/nlhome/m056/hous0042/asimov.html > for an idea that is consistant with Steve and Timothy's objections. > > i.e. reflection transferrs momentum to the normal, and absorbtion > transfers momentum in the direction of the photons original vector. > > Advance billing: it is _still_ possible to cancel the momentum within the > structure of the antenna/sail . > > HA! We'll see. You must either absorb the photon and thereby absorb its momentum, or reflect the photon and get momentum to balance the change in direction of the photon. The only way to not get any momentum change is to either not interact with the photon or reflect it so as to leave it travelling in the same direction it came with the same energy. If the system consisting of the photon beam and the spaceship plus sail assembly doesn't have the same momentum after the interaction as before, then you'll have to go back to the drawing board. Perhaps after a brief refresher course in physics. From popserver Sun Nov 26 02:03:31 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2224" "Sun" "26" "November" "1995" "02:59:48" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "70" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA26658; Sat, 25 Nov 95 17:57:27 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA23853 (5.67b/IDA-1.5 for ); Sun, 26 Nov 1995 02:59:44 +0100 Message-Id: <199511260159.AA23853@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817351221.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sun, 26 Nov 1995 02:59:48 +0100 ReplyTo : The Nitwit ReplyFrom : Nitpicker Timothy Hi Steve, I'm sorry to have frustrated you. The reason I'm doing that is because you are always finding these wonderful solutions and I can't stand that. :) No, not really of course, but it is really difficult, as we all know by now, to find a method to harnas these amounts of energy. I guess, if there was a easy and cheap way we would have found it by now. We all are hoping to find some ingenious way to get around all the problems at once, so all solutions are welcome. But also there is a great possibility that these solutions will fail. The only thing I can write is, let the new ideas come and try to explain why you think they work. Before you read any further I have to warn you :) TAKE SOME VALIUM TABLETS AND TRY TO RELAX... >see my web page >http://www.umn.edu/nlhome/m056/hous0042/asimov.html >for an idea that is consistant with Steve and Timothy's objections. I almost dare not saying it but, how accurate is your calculator? Let me recalculate the values of the various components: a=55.47 m/s^2 (purple) b=27.73 m/s^2 (red) Purple x-comp = a sin( 21) = 19.88 (you got 51.62) Purple y-comp = a cos( 21) = 51.79 (you got 20.3023) Red x-comp = b cos(-48) = -18.55 (you got -18.9) Red y-comp = b sin(-48) = -20.61 (you got -20.3021) I checked all cos and sin formulas in the drawing and all seem to be OK, the only things that are wrong are the final decimal numbers. If you now sum the several components: x=19.88-18.55=1.33 y=51.79-20.61=31.18 (This value is too high to compensate) (You wrote the formulas where you calculated the accelerations wrong but the answers seemed right) If you think other angles would make your system work, I still am certain it won't work. If you want to give it a try here are more general formulas: t is the angle for which you took 21 a=2b (reflected momentum is twice the absorbed momentum) remember t is between 0 and 90 Px=2b sin(t) Py=2b cos(t) Rx=b cos(-2t) Ry=b sin(-2t) x=Px+Rx=2b sin(t) + b cos(-2t) y=Py+Ry=2b cos(t) + b sin(-2t) only t=90 will make y equal to zero, but t=90 means the light goes straight on, whithout touching the mirror or absorber. Good luck, Timothy From popserver Sun Nov 26 02:53:50 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1944" "Sat" "25" "November" "1995" "20:46:38" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "50" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA28253; Sat, 25 Nov 95 18:45:00 PST Received: by maroon.tc.umn.edu; Sat, 25 Nov 95 20:46:38 -0600 In-Reply-To: <199511260108.RAA08463@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817354240.000 From: Kevin C Houston To: Steve VanDevender Cc: Steve VanDevender , Timothy van der Linden , KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 25 Nov 1995 20:46:38 -0600 (CST) On Sat, 25 Nov 1995, Steve VanDevender wrote: > Kevin C. Houston writes: > > To: all nitpickers > > From: A nit(wit) who is tired of getting picked on. ;) > > Sorry, but conservation of energy and momentum are too > fundamental to ignore. If you can't follow those rules then you > may as well give up and design a warp drive, since you're > throwing out the laws of physics anyway. Would if I could, but I can't, so I won't. > > > see my web page > > http://www.umn.edu/nlhome/m056/hous0042/asimov.html > > for an idea that is consistant with Steve and Timothy's objections. > > > > i.e. reflection transferrs momentum to the normal, and absorbtion > > transfers momentum in the direction of the photons original vector. > > > > Advance billing: it is _still_ possible to cancel the momentum within the > > structure of the antenna/sail . > > > > HA! > > We'll see. You must either absorb the photon and thereby absorb > its momentum, or reflect the photon and get momentum to balance > the change in direction of the photon. The only way to not get > any momentum change is to either not interact with the photon or > reflect it so as to leave it travelling in the same direction it > came with the same energy. > no, first the photon is reflected at an angle, this dumps some of the momentum into the perpendicular directionthe photon leaves the first sail element (reflection) and is absorbed in the second, inner element. as far as that element is concerned, the photon came from the _front_ of the ship. > If the system consisting of the photon beam and the spaceship > plus sail assembly doesn't have the same momentum after the > interaction as before, then you'll have to go back to the drawing > board. Perhaps after a brief refresher course in physics. > it does have the same momentum, just that some of that momentum has been made to cancel out. equal but opposite momentums cancel out From popserver Sun Nov 26 02:53:52 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7812" "Sat" "25" "November" "1995" "18:48:43" "-0800" "Steve VanDevender" "stevev@efn.org" nil "162" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA28288; Sat, 25 Nov 95 18:45:40 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id SAA08671; Sat, 25 Nov 1995 18:48:43 -0800 Message-Id: <199511260248.SAA08671@tzadkiel.efn.org> In-Reply-To: <199511252351.AA19695@student.utwente.nl> References: <199511252351.AA19695@student.utwente.nl> X-UIDL: 817354240.001 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sat, 25 Nov 1995 18:48:43 -0800 Timothy van der Linden writes: > > > I have a lot of problem bying the idea that the light bouncing > > > off a sail doesn't lose energy proportional to the kinetic or > > > heat energy gain of the ship. Th power has to be coming from > > > somewhere. > > > >If the sail is reflective to the incident photon, then the photon > >doesn't lose energy as a result of reflection. The ship changes > >velocity because the photon changes direction. That's where the > >"power" comes from. > > I think I can't agree with that Steve, when the photon enters the first > stage of the reflection, i.e. absorption, it adds some momentum to the ship. > So the velocity of the ship increases. Now we enter the second stage of > reflection, re-transmission. Relative to the ship the outgoing wavelength of > the photon is the same as the incoming photon (because of invariance). But > the observer at rest sees that that transmitted photon has dopplershifted > (nice verb) and thus lost some energy. > > This is the same principle the police uses to measure speeding cars with radar. And I don't disagree with that analysis; it's correct in a frame where the ship is moving. In that frame, the photon has more energy and momentum, and while it changes momentum by the same amount as in the frame where the ship is "stationary", this necessarily results in a different-looking scenario. > >What happens to the mirrors? What happens to the light pulse? > >An answer describing the limit state of the mirrors and light > >pulse is acceptable; you don't have to perform a step-by-step > >analysis of each reflection. > > Assuming these mirrors have mass, they indeed will get some velocity that > correspondends to the same momentum as the photon. By each reflection the > photon will loose some momentum and lower its wavelength. This is exactly the analysis I came up with. In the limit the mirrors carry the momentum of the light pulse, and the light pulse fades to nothing. > >> I've always looked at is as follows: When you move faster and faster, part > >> of the energy is transformed into mass, the other part is used to get the > >> extra momentum. > > > >I used to look at it this way, but Taylor and Wheeler talked me > >out of it (see chapter 8 of _Spacetime Physics_ for a lengthy, > >careful discussion on "Use and Abuse of the Concept of Mass"). > >The problem here is that relative velocity or acceleration do not > >cause any fundamental changes in the structure of the moving > >object. Where is this extra mass? If it's really stashed on the > >ship somewhere then the people on the ship could measure it. But > >they don't feel the ship getting heavier or see any increase in > >the mass of the ship in their frame. > > I wrote it wrong the first time, indeed then the mass must be somewhere on > the ship. But look at it this way: When an object starts moving it deforms > space-time in such a way that the object looks heavier to the outside world > and the other way around, i.e. the object "notices" the outside world to be > heavier. > This means that locally no mass increase is measured, for the same reason > that locally no length contraction or time dilation is measured. Taylor and Wheeler say it better than I can. Their approach is based on years of teaching special relativity to new students, which is why I give it credence. So, to quote Taylor and Wheeler: Q: If the factor c^2 is not the central feature of the relationship between mass and energy, what _is_ central? A: The distinction between mass and energy is this: Mass is the magnitude of the momenergy 4-vector and energy is the time component of the same vector. Any feature of this discussion that emphasizes this contrast is an aid to understanding. Any slurring of terminology that obscures this distinction is a potential source of error or confusion. Q: Is the mass of a moving object greater than the mass of the same object at rest? A: No. It is the same whether the object is at rest or in motion; the same in all frames. To explain some of their terminology: Taylor and Wheeler teach relativistic kinematics using the notion of "momenergy". Since energy is conserved and the vector quantity of momentum is conserved in a system, they express the entire state of an object or system using a 4-vector that combines both quantities, which they call a "momenergy vector". An object's state of motion can be expressed as a vector of the form [ E px py pz ], where E is the object's energy and [ px py pz ] are the components of the object's momentum. Since vectors are normally added component by component, adding momenergy vectors preserves the conservation of the individual components. The other notion that they introduce at the very beginning of the book is that relativistic spacetime is non-Euclidean, even in special relativity. A vector of the form [ t x y z ] is defined to have magnitude sqrt(t^2 - x^2 - y^2 - z^2), which results in non-zero vectors that have magnitude zero (or even imaginary magnitude). The magnitude of a momenergy vector is exactly the mass of the system described by that vector. The only time that mass is equivalent to energy is when momentum is zero, or in a frame in which the object in question is at rest. > >Taylor and Wheeler's wisdom on the subject is that the definition > >of mass is sqrt(E^2 - p^2); then every observer sees the same > >mass for the same object, no matter what their relative motion. > > How do you measure E and p? E seems to be relativistic mass and p > relativistic momentum. (E=gamma*m_rest p=gamma*m_rest*v) > I would measure the perceived relativistic mass and the relative velocity. > As far as I can see, doing that all observers will also agree about the rest > mass. Another quote from Taylor and Wheeler: Q: In order to make this point clear, should we call invariant mass of a particle rest mass? A: That is what we called it in the first edition of this book. But a thoughtful student pointed out that the phrase "rest mass" is also subject to misunderstanding: What happens to the "rest mass" of a particle when the particle moves? In reality mass is mass is mass. Mass has the same value in all frames, is invariant, no matter how the particle moves. [Galileo: "In questions of science the authority of a thousand is not worth the humble reasoning of a single individual."] The way I was taught to measure mass is as sqrt(E^2 - p^2). So the mass of a particle with energy E = gamma * m_rest and momentum p = gamma * m_rest * v (where v is a vector) is m^2 = E^2 - p^2 = gamma^2 * m_rest^2 - gamma^2 * m_rest^2 * abs(v)^2 = gamma^2 * m_rest^2 * (1 - abs(v)^2) = m_rest^2 (gamma is 1/sqrt(1 - abs(v)^2)). So no matter how the particle moves it has the same mass. Mass is not energy. What you call "relativistic mass" I call energy; what I call "mass" you seem to want to call "rest mass", yet the quantity "mass" that I am using doesn't vary with motion. > >If, on the other hand, a moving object did exert greater > >gravitation than a stationary object of the same mass, I'd > >probably be looking for a relation to a quantity that did change, > >like the object's total energy. > > So that would mean that some of the change in energy is change of > gravitational energy, from which I would conclude that it comes from extra > mass (or bending of space time). First you have to convince me that a moving object really does exert more gravitational force. > Is it this translation of energy to mass that gives the trouble? It is that my studies of relativistic kinematics do not allow for the treatment of energy and mass as identical quantities. From popserver Sun Nov 26 03:19:04 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2340" "Sat" "25" "November" "1995" "21:16:30" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "61" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA29217; Sat, 25 Nov 95 19:14:58 PST Received: by maroon.tc.umn.edu; Sat, 25 Nov 95 21:16:31 -0600 In-Reply-To: <199511260159.AA23853@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817355753.000 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 25 Nov 1995 21:16:30 -0600 (CST) On Sun, 26 Nov 1995, Timothy van der Linden wrote: > ReplyTo : The Nitwit BTW, in english, a nitwit is a stupid person. (someone with the brains of a nit ) in so naming myself, I admit my previous errors > ReplyFrom : Nitpicker Timothy > > Hi Steve, I'm sorry to have frustrated you. actually, it's Kevin, I know it can be confusing when three or more people are engaged in debate, but try to keep us straight. It's not nice to insult Steve's intelligence like that. > The reason I'm doing that is because you are always finding these wonderful > solutions and I can't stand that. :) No, not really of course, but it is > really difficult, as we all know by now, to find a method to harnas these > amounts of energy. I guess, if there was a easy and cheap way we would have > found it by now. We all are hoping to find some ingenious way to get around > all the problems at once, so all solutions are welcome. But also there is a > great possibility that these solutions will fail. > > The only thing I can write is, let the new ideas come and try to explain why > you think they work. > > Before you read any further I have to warn you :) > > TAKE SOME VALIUM TABLETS AND TRY TO RELAX... > > >see my web page > >http://www.umn.edu/nlhome/m056/hous0042/asimov.html > >for an idea that is consistant with Steve and Timothy's objections. > > I almost dare not saying it but, how accurate is your calculator? > not very, considering i lost it (or it was stolen), I've been using EXCEL for my calculations, also, I rounded the actual angle of the sail elements from 21.47 to 21 > Let me recalculate the values of the various components: > > a=55.47 m/s^2 (purple) b=27.73 m/s^2 (red) > > Purple x-comp = a sin( 21) = 19.88 (you got 51.62) > Purple y-comp = a cos( 21) = 51.79 (you got 20.3023) it is possible i mixed these two up, and _wrote_ a sin, when i _meant_ a cos. I will have to check the spreadsheet and the web page. Other than that, I think the other errors are from rounding. > Red x-comp = b cos(-48) = -18.55 (you got -18.9) > Red y-comp = b sin(-48) = -20.61 (you got -20.3021) > > I checked all cos and sin formulas in the drawing and all seem to be OK, the > only things that are wrong are the final decimal numbers. I will check that and get back to you. From popserver Sun Nov 26 06:58:02 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5058" "Sat" "25" "November" "1995" "22:53:57" "-0800" "Steve VanDevender" "stevev@efn.org" nil "94" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA06408; Sat, 25 Nov 95 22:50:53 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id WAA09366; Sat, 25 Nov 1995 22:53:57 -0800 Message-Id: <199511260653.WAA09366@tzadkiel.efn.org> In-Reply-To: References: <199511260108.RAA08463@tzadkiel.efn.org> X-UIDL: 817368889.001 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , Timothy van der Linden , KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 25 Nov 1995 22:53:57 -0800 Kevin C. Houston writes: > > We'll see. You must either absorb the photon and thereby absorb > > its momentum, or reflect the photon and get momentum to balance > > the change in direction of the photon. The only way to not get > > any momentum change is to either not interact with the photon or > > reflect it so as to leave it travelling in the same direction it > > came with the same energy. > > no, first the photon is reflected at an angle, this dumps some of the > momentum into the perpendicular directionthe photon leaves the first sail > element (reflection) and is absorbed in the second, inner element. as > far as that element is concerned, the photon came from the _front_ of the > ship. Look, I'm not doing this to dump on your parade, but it's a very simple check that I'm doing on your proposed solution to verify that it satisfies the laws of physics. We are looking at a system consisting of some quantity of photons with total momenergy [ p p 0 0 ] and a spacecraft with momenergy [ m 0 0 0 ], as seen in the frame where the spacecraft is initially at rest. No matter what, whether or not these two components interact, then the final total momenergy of all the resulting components must sum to [ m+p p 0 0 ]; in other words, the system has net forward momentum p always and forever. This is fundamental and inescapable. If you start out with a big box containing the photons and the spacecraft, then that box always has the same forward momentum for as long as all the original components remain in the box and nothing new is put in the box. Even worse for your argument, you are specifying that the photons are entirely absorbed by the spacecraft, meaning that the only component that is left after the interaction is the spacecraft, which must then have all the forward momentum. I know that my argument barely even uses math and must seem too simple to refute all the work you've put into this, but your solution fails to conserve momentum and is therefore physically invalid. > > If the system consisting of the photon beam and the spaceship > > plus sail assembly doesn't have the same momentum after the > > interaction as before, then you'll have to go back to the drawing > > board. Perhaps after a brief refresher course in physics. > > it does have the same momentum, just that some of that momentum has been > made to cancel out. equal but opposite momentums cancel out I think what your analysis is failing to account for, at some level, is that momentum is a vector quantity. Your think you have found a way to turn around part of the momentum and pit it against itself. Unfortunately that can't satisfy conservation of momentum. Not just the magnitude of the total system momentum, but the direction, must be conserved. You can't "dump momentum in the perpendicular direction.". Any forward momentum that you take away from the beam _must_ be transferred to the ship, whether the beam is reflected or absorbed, no matter the angle of the reflecting or absorbing surface; it cannot be transferred to momentum in any other direction. The structural loading caused by the beam does not absorb momentum continuously, because momentum implies motion -- unless you unhook the reflector or cut it into pieces, the reflector cannot accept momentum separately from the ship because it cannot move relative to the ship; a tiny amount of momentum goes into stretching the ship's structure when the beam is first turned on, and accounts for no more absorption after that. The only way to cancel out a quantity of momentum is to accept it from another source; you cannot take a single source of momentum and use one part of it to cancel another part of it. Again, let's start with what you've got -- photons with momenergy [ p p 0 0 ], and a spacecraft with momenergy [ m 0 0 0 ], for a total system momenergy [ m+p p 0 0 ]. When the photons bounce off the conical reflector tilted at an angle a, it changes the total photon momenergy from [ p p 0 0 ] to [ p*cos(2*a) -p*cos(2*a) 0 0 ]. The spacecraft then changes momenergy to [ m+p*(1-cos(2*a)) p*(1+cos(2*a)) 0 0 ]. The total system momenergy is still [ m+p p 0 0 ]. You have pitted the photon beam against itself, because the beam has been decollimated and individual photons now have sideways momentum that sums to zero for the entire beam, but that doesn't mean that the spacecraft doesn't gain momentum and energy to conserve the system momenergy [ m+p p 0 0 ]. Now the photons with momenergy [ p*cos(2*a) -p*cos(2*a) 0 0 ] travel back and hit the absorber (which need not be tilted or conical itself; it could just be a long column down the axis of the conical reflector). They transfer their momenergy into the collector, so the spacecraft momenergy changes to [ m+p p 0 0 ]. The spacecraft has net forward momentum. Momenergy has been conserved at all times throughout. There is no way to absorb the photons without absorbing their momentum. "I canna change the laws of physics, Captain." -- Chief Engineer Scott From popserver Sun Nov 26 23:12:13 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["5755" "Sun" "26" "November" "1995" "17:39:02" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199511261638.AA18646@student.utwente.nl>" "141" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA23834; Sun, 26 Nov 95 08:36:51 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA18646 (5.67b/IDA-1.5 for ); Sun, 26 Nov 1995 17:38:56 +0100 Message-Id: <199511261638.AA18646@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817427321.009 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sun, 26 Nov 1995 17:39:02 +0100 Reply To : Steve Reply From : Timothy >> I think I can't agree with that Steve, when the photon enters the first >> stage of the reflection, i.e. absorption, it adds some momentum to the ship. >> So the velocity of the ship increases. Now we enter the second stage of >> reflection, re-transmission. Relative to the ship the outgoing wavelength of >> the photon is the same as the incoming photon (because of invariance). But >> the observer at rest sees that that transmitted photon has dopplershifted >> (nice verb) and thus lost some energy. > >And I don't disagree with that analysis; it's correct in a frame >where the ship is moving. In that frame, the photon has more >energy and momentum, and while it changes momentum by the same >amount as in the frame where the ship is "stationary", this >necessarily results in a different-looking scenario. I was wrong to compare it with the police radar, so forget that part. But I still don't see what was wrong with part preceding it. o you say the photon looses energy if it accelerates the ship or do you say that the energy of the photon stays the same? What does that different scenario look like? >> Assuming these mirrors have mass, they indeed will get some velocity that >> correspondends to the same momentum as the photon. By each reflection the >> photon will loose some momentum and lower its wavelength. > >This is exactly the analysis I came up with. In the limit the >mirrors carry the momentum of the light pulse, and the light >pulse fades to nothing. Somehow we seem to agree on this, but I'm not sure why. >The way I was taught to measure mass is as sqrt(E^2 - p^2). So >the mass of a particle with energy E = gamma * m_rest and >momentum p = gamma * m_rest * v (where v is a vector) is > >m^2 = E^2 - p^2 > = gamma^2 * m_rest^2 - gamma^2 * m_rest^2 * abs(v)^2 > = gamma^2 * m_rest^2 * (1 - abs(v)^2) > = m_rest^2 > >(gamma is 1/sqrt(1 - abs(v)^2)). So no matter how the particle >moves it has the same mass. Mass is not energy. What you call >"relativistic mass" I call energy; what I call "mass" you seem to >want to call "rest mass", yet the quantity "mass" that I am using >doesn't vary with motion. This is what I was feeling; We think the same but use different terminology. What you call mass doesn't vary. I call that quantity rest-mass and that doesn't vary either. Taylor and Wheeler tell us that rest-mass revokes a potential misunderstanding so they call it invariant mass. I don't see why rest-mass would change when a body starts moving, I guess I've grown above that misunderstanding. You say the energy changes while I say the relativistic-mass or the kinetic energy changes. This kinetic energy is not the classical 0.5mv^2 but m_rest*c^2(gamma-1) Or more clear the total energy minus the rest-energy. > > >If, on the other hand, a moving object did exert greater > > >gravitation than a stationary object of the same mass, I'd > > >probably be looking for a relation to a quantity that did change, > > >like the object's total energy. > > > > So that would mean that some of the change in energy is change of > > gravitational energy, from which I would conclude that it comes from extra > > mass (or bending of space time). > >First you have to convince me that a moving object really does >exert more gravitational force. Let me quote a few sentences of "Introducing Einstein's relativity" by Ray d'Inverno in the paragraph "The principle of equivalence": Next, we wish to make explicit the assumption that matter both responds to, and is a source of, a gravitational field. However, we have seen in special relativity that matter and energy are equivalent, so the statement about the gravitational field applies to energy as well. This means that even photons excert and react to gravity as well as all other kinds of energy. I would conclude from this that moving bodies excert greater gravitation either because of gain of mass or gain of energy. I feel both can be used, its a bit like the wave-particle duality. >> Is it this translation of energy to mass that gives the trouble? > >It is that my studies of relativistic kinematics do not allow for >the treatment of energy and mass as identical quantities. They are indeed not identical but equivalent, meaning they can be be interchanged. =============================================================================== ReplyTo : Kevin ReplyFrom : Tim >BTW, in english, a nitwit is a stupid person. (someone with the brains >of a nit ) in so naming myself, I admit my previous errors Yes, I knew, I looked it up in a dictionary, it was just a repeat of your own words. >actually, it's Kevin, I know it can be confusing when three or more >people are engaged in debate, but try to keep us straight. It's not nice >to insult Steve's intelligence like that. I guess, it was a bit late when I wrote that just after I finished the letter to Steve which occupied my mind. >not very, considering i lost it (or it was stolen), I've been using EXCEL >for my calculations, also, I rounded the actual angle of the sail >elements from 21.47 to 21 I figured you used tables or something like that. Anyway here are some extra corrections of my calculations: >> Red x-comp = b cos(-48) = -18.55 (you got -18.9) ^ should be positive And I made mistakes in the general formulas, so here are the right ones: Px=2b sin(t) Py=2b cos(t) Rx=b sin(2t-180)=- b sin(2t) Ry=b cos(2t-180)=- b cos(2t) x=Px+Rx=2b sin(t) - b sin(2t) y=Py+Ry=2b cos(t) - b cos(2t) t=90 gives y=b which is logical because that means that if there is no mirror the energy is captured right away. Every other angle makes the problem worse! From popserver Sun Nov 26 23:12:20 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["5258" "Sun" "26" "November" "1995" "12:40:51" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "122" "Okay, I give up ( well, not exactly ;)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA01070; Sun, 26 Nov 95 10:39:09 PST Received: by maroon.tc.umn.edu; Sun, 26 Nov 95 12:40:52 -0600 In-Reply-To: <199511260653.WAA09366@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817427321.014 From: Kevin C Houston To: Steve VanDevender Cc: Timothy van der Linden , KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David Levine Subject: Okay, I give up ( well, not exactly ;) Date: Sun, 26 Nov 1995 12:40:51 -0600 (CST) On Sat, 25 Nov 1995, Steve VanDevender wrote: > Look, I'm not doing this to dump on your parade, but it's a very > simple check that I'm doing on your proposed solution to verify > that it satisfies the laws of physics. i know you aren't doing this to be mean, I'm just frustrated by the situation. I checked my spreadsheet again, and found a cos where a sin should be, and vice versa. > > We are looking at a system consisting of some quantity of photons > with total momenergy [ p p 0 0 ] and a spacecraft with momenergy > [ m 0 0 0 ], as seen in the frame where the spacecraft is > initially at rest. No matter what, whether or not these two > components interact, then the final total momenergy of all the > resulting components must sum to [ m+p p 0 0 ]; in other words, > the system has net forward momentum p always and forever. This > is fundamental and inescapable. If you start out with a big box > containing the photons and the spacecraft, then that box always > has the same forward momentum for as long as all the original > components remain in the box and nothing new is put in the box. > Even worse for your argument, you are specifying that the photons > are entirely absorbed by the spacecraft, meaning that the only > component that is left after the interaction is the spacecraft, > which must then have all the forward momentum. > Yes, I should have known this. in Chem Eng, we use the concept of a control volume all the time. > I know that my argument barely even uses math and must seem too > simple to refute all the work you've put into this, but your > solution fails to conserve momentum and is therefore physically > invalid. > Simple arguments can convince simple minds (like mine) > > it does have the same momentum, just that some of that momentum has been > > made to cancel out. equal but opposite momentums cancel out > > I think what your analysis is failing to account for, at some > level, is that momentum is a vector quantity. Your think you > have found a way to turn around part of the momentum and pit it > against itself. Unfortunately that can't satisfy conservation of > momentum. Not just the magnitude of the total system momentum, > but the direction, must be conserved. You can't "dump momentum > in the perpendicular direction.". Any forward momentum that you > take away from the beam _must_ be transferred to the ship, > whether the beam is reflected or absorbed, no matter the angle of > the reflecting or absorbing surface; it cannot be transferred to > momentum in any other direction. The structural loading caused > by the beam does not absorb momentum continuously, because > momentum implies motion -- unless you unhook the reflector or cut > it into pieces, the reflector cannot accept momentum separately > from the ship because it cannot move relative to the ship; a tiny > amount of momentum goes into stretching the ship's structure when > the beam is first turned on, and accounts for no more absorption > after that. The only way to cancel out a quantity of momentum is > to accept it from another source; you cannot take a single source > of momentum and use one part of it to cancel another part of it. Agreed that the way i proposed won't work, why can't a single source be decomposed and used to cancel itself? It can be done with light, a single beam can be split, half the beam can have it's phase delayed by 1/2 wavelength, and then recombined with the other half of the beam, the net result is _nothing_ no beam. they destructively interfere. Since any particle or energy can be considered a wave, (debroglie wave for momentum) why can't this same trick be used? > > "I canna change the laws of physics, Captain." > -- Chief Engineer Scott "any science, sufficiently advanced, is indistinguishable from magic" -- Arthur C Clarke Okay, If I can't raise the bridge, perhaps I can lower the river. in studying the equations again, the big problem seem to be the exhaust velocity. (I think we knew all along that Ve= .99996 C was impossible) if i turn down the Exhaust velocity, then the exhaust invarient mass must increase. The original reason to increase the exhaust velocity was to conserve RM. but if we can use a maser sail for the first half of the trip, we might be able to accept a higher RM rate for the decell portion of the trip. so here's what I need: a simple easy to use, relativisticlly correct formula that tells me how much energy I need to accelerate a given exhaust mass to a given speed. I'll be using Me=G*(Ms+Mf) * gamma/(Ve *C) where Ve is exhaust Velocity expressed as a fraction of C. Me is Exhaust Mass. Ms is ship's Mass. Mf is Reaction Mass. G is ship's acceleration. gamma is SQRT(1 - Ve^2) I know Tim likes gamma= 1/sqrt(1-Ve^2), but then he divides by it instead of multipling. all mass is invarient or rest mass. Ve is with respect to the ship, and I'm thinking it'll be in the .80-.9? perecent of C range. every time I try to calculate this, I get flamed for using the wrong formula. Timothy gave me one, but then said that you (Steve) had problems with it. so I thought I'd head off any potential problems by asking for the right formula ahead of time. Kevin From popserver Sun Nov 26 23:12:40 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1671" "Sun" "26" "November" "1995" "23:19:37" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "47" "Re: Okay, I give up ( well, not exactly ;)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA12507; Sun, 26 Nov 95 14:17:14 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA01202 (5.67b/IDA-1.5 for ); Sun, 26 Nov 1995 23:19:34 +0100 Message-Id: <199511262219.AA01202@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817427321.029 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Okay, I give up ( well, not exactly ;) Date: Sun, 26 Nov 1995 23:19:37 +0100 >if i turn down the Exhaust velocity, then the exhaust invarient mass must >increase. The original reason to increase the exhaust velocity was to >conserve RM. but if we can use a maser sail for the first half of the >trip, we might be able to accept a higher RM rate for the decell portion >of the trip. Going from 0.99996c to 0.85c means about 60 times more reaction mass... Plus since we can't use a maser beam for energy we have to bring the energy ourselves. >so here's what I need: > >a simple easy to use, relativisticlly correct formula that tells me how much >energy I need to accelerate a given exhaust mass to a given speed. > >I'll be using Me=G*(Ms+Mf) * gamma/(Ve *C) > >where >Ve is exhaust Velocity expressed as a fraction of C. >Me is Exhaust Mass. >Ms is ship's Mass. >Mf is Reaction Mass. >G is ship's acceleration. >gamma is SQRT(1 - Ve^2) I know Tim likes gamma= 1/sqrt(1-Ve^2), but then > he divides by it instead of multipling. In most formulas I use, I have to multiply by gamma. Your formula is one of few where I have to devide by it. >all mass is invarient or rest mass. >Ve is with respect to the ship, and I'm thinking it'll be in the .80-.9? >perecent of C range. To calculate the kinetic energy of a mass M use: K=M C^2 (1/gamma - 1) where gamma is according to your (unusual?) definition. You can substitute Me for M and simplify: K=G C (Ms+Mf) (1-gamma)/Ve (gamma is still according to your definition) Timothy P.S. If you are planning to calculate how much energy is needed to accelerate the Asimov and it's fuel&reaction mass for specific G, I've to tell you that these calculations have been done already. From popserver Mon Nov 27 00:28:25 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3760" "Sun" "26" "November" "1995" "16:25:36" "-0800" "Steve VanDevender" "stevev@efn.org" nil "93" "Okay, I give up ( well, not exactly ;)" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA19292; Sun, 26 Nov 95 16:22:32 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id QAA11700; Sun, 26 Nov 1995 16:25:36 -0800 Message-Id: <199511270025.QAA11700@tzadkiel.efn.org> In-Reply-To: References: <199511260653.WAA09366@tzadkiel.efn.org> X-UIDL: 817431908.000 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , Timothy van der Linden , KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David Levine Subject: Okay, I give up ( well, not exactly ;) Date: Sun, 26 Nov 1995 16:25:36 -0800 Kevin C. Houston writes: > > The only way to cancel out a quantity of momentum is > > to accept it from another source; you cannot take a single source > > of momentum and use one part of it to cancel another part of it. > > Agreed that the way i proposed won't work, why can't a single source be > decomposed and used to cancel itself? It can be done with light, a > single beam can be split, half the beam can have it's phase delayed by > 1/2 wavelength, and then recombined with the other half of the beam, the > net result is _nothing_ no beam. they destructively interfere. Since > any particle or energy can be considered a wave, (debroglie wave for > momentum) why can't this same trick be used? No matter what, the momentum has to go somewhere. You can't split a momentum vector in half and turn one of the halves around without creating another momentum vector of magnitude and direction equal to the original to preserve conservation. If you use a mirror to reflect half of the light back on itself, then you get all the momentum of the original beam -- the mirror (and whatever it's attached to) acquires 2 * (1/2 * p) = p momentum for reflecting half of the beam backwards. If you take half the beam and delay it by half a wavelength before retransmitting it forward to combine with the other half of the beam, you don't get the momentum, but you also don't get any of the energy. Unfortunately I'm at a bit of a loss to say where the momentum goes in this case. I also don't think that out-of-phase photons annihilate when they meet. In the region that the out-of-phase photons overlap, they cancel, but they can't just disappear forever. > > "I canna change the laws of physics, Captain." > > -- Chief Engineer Scott > > "any science, sufficiently advanced, is indistinguishable from magic" > -- Arthur C Clarke Any science, sufficiently advanced, still cannot violate its own fundamental laws. > so here's what I need: > > a simple easy to use, relativisticlly correct formula that > tells me how much energy I need to accelerate a given exhaust > mass to a given speed. As far as I know, that can be done with the standard relativistic kinetic energy formula: KE = m * c^2 * ((1 / sqrt(1 - v^2 / c^2)) - 1) > I'll be using Me=G*(Ms+Mf) * gamma/(Ve *C) > > where > Ve is exhaust Velocity expressed as a fraction of C. > Me is Exhaust Mass. > Ms is ship's Mass. > Mf is Reaction Mass. > G is ship's acceleration. > gamma is SQRT(1 - Ve^2) I know Tim likes gamma= 1/sqrt(1-Ve^2), but then > he divides by it instead of multipling. > > all mass is invarient or rest mass. > Ve is with respect to the ship, and I'm thinking it'll be in the .80-.9? > perecent of C range. Whoa. Where did this come from? How is this related to your requirement above? You should know that _every_ text I've read says that gamma is 1 / sqrt(1 - v^2), so your use is unconventional and may confuse people. Could you at least give some information about how you derived this? I can say right off that it doesn't look right because it doesn't have consistent units; the right-hand side evaluates to units of kg/s. > every time I try to calculate this, I get flamed for using the > wrong formula. Timothy gave me one, but then said that you > (Steve) had problems with it. so I thought I'd head off any > potential problems by asking for the right formula ahead of > time. I don't remember when I might have said this or what formula it was about any more. I'll get back to you on the formula question. I can adapt some of the work I did before, but I think it would be more useful if I cast it in terms of reaction mass and payload mass rather than fractional quantities. From popserver Mon Nov 27 00:53:37 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4157" "Sun" "26" "November" "1995" "16:49:49" "-0800" "Steve VanDevender" "stevev@efn.org" nil "99" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA20876; Sun, 26 Nov 95 16:46:40 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id QAA11752; Sun, 26 Nov 1995 16:49:49 -0800 Message-Id: <199511270049.QAA11752@tzadkiel.efn.org> In-Reply-To: <199511261638.AA18646@student.utwente.nl> References: <199511261638.AA18646@student.utwente.nl> X-UIDL: 817433420.000 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sun, 26 Nov 1995 16:49:49 -0800 Timothy van der Linden writes: > >And I don't disagree with that analysis; it's correct in a frame > >where the ship is moving. In that frame, the photon has more > >energy and momentum, and while it changes momentum by the same > >amount as in the frame where the ship is "stationary", this > >necessarily results in a different-looking scenario. > > I was wrong to compare it with the police radar, so forget that part. But I > still don't see what was wrong with part preceding it. > o you say the photon looses energy if it accelerates the ship or do you say > that the energy of the photon stays the same? > What does that different scenario look like? In a frame where the ship is in motion, the photon changes energy when it bounces off the ship; its reflected energy is less than the incident energy if the ship receding, greater if the ship is approaching. You actually were right to compare this to doppler radar, because it's this effect that doppler radar measures to determine velocity. > >> Assuming these mirrors have mass, they indeed will get some velocity that > >> correspondends to the same momentum as the photon. By each reflection the > >> photon will loose some momentum and lower its wavelength. > > > >This is exactly the analysis I came up with. In the limit the > >mirrors carry the momentum of the light pulse, and the light > >pulse fades to nothing. > > Somehow we seem to agree on this, but I'm not sure why. Because we're both thinking about it the right way? :-) > >First you have to convince me that a moving object really does > >exert more gravitational force. > > Let me quote a few sentences of "Introducing Einstein's relativity" by Ray > d'Inverno in the paragraph "The principle of equivalence": > > Next, we wish to make explicit the assumption that matter > both responds to, and is a source of, a gravitational > field. However, we have seen in special relativity that > matter and energy are equivalent, so the statement about the > gravitational field applies to energy as well. > > This means that even photons excert and react to gravity as well as all > other kinds of energy. This is true, but it's more complicated than you make it out to be. Note that I will continue to use Taylor and Wheeler's terminology, so when I say "mass", I mean invariant mass. A photon is massless, because it has energy equal to its momentum, and the magnitude of its momenergy vector is 0. However, multiple photons considered as a system may not be massless! For example, two photons with energy/momentum p travelling in opposite directions have mass 2p: [ p p 0 0 ] + [ p -p 0 0 ] = [ 2*p 0 0 0 ] magnitude [ 2*p 0 0 0 ] = 2*p Two photons travelling at right angles to each other also have mass: [ p p 0 0 ] + [ p 0 p 0 ] = [ 2*p p p 0 ] magnitude [ 2*p p p 0 ] = sqrt(2) * p Two photons travelling in parallel have no mass: magnitude [ 2*p 2*p 0 0 ] = 0 An absorber gains mass as well as momentum from a massless photon: [ m 0 0 0 ] + [ p p 0 0 ] = [ m+p p 0 0 ] magnitude [ m+p p 0 0 ] = sqrt((m + p)^2 - p^2) = sqrt(m^2 + 2 * p * m) Mass is a more subtle concept than energy; while energies add linearly, masses as magnitudes of momenergy vectors do not. > I would conclude from this that moving bodies excert greater gravitation > either because of gain of mass or gain of energy. I feel both can be used, > its a bit like the wave-particle duality. What I really want to see is the general relativistic formula that says whether spacetime curvature is the result of an object's mass or its energy. > >> Is it this translation of energy to mass that gives the trouble? > > > >It is that my studies of relativistic kinematics do not allow for > >the treatment of energy and mass as identical quantities. > > They are indeed not identical but equivalent, meaning they can be be > interchanged. Not in Taylor and Wheeler's terminology. The only time they allow mass and energy to be spoken of as equivalent is when you are dealing with an object in its rest frame. In any other frame the object's energy is not equivalent to its mass. From popserver Mon Nov 27 06:12:58 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["991" "Sun" "26" "November" "1995" "22:46:11" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951126224608_34896815@emout05.mail.aol.com>" "21" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA29951; Sun, 26 Nov 95 19:46:00 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id WAA21545; Sun, 26 Nov 1995 22:46:11 -0500 Message-Id: <951126224608_34896815@emout05.mail.aol.com> X-UIDL: 817452572.003 From: KellySt@aol.com To: stevev@efn.org Cc: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu Subject: Re: Engineering Newsletter Date: Sun, 26 Nov 1995 22:46:11 -0500 KellySt@aol.com writes: > The papers I've seen on on solar sails seem to disagree with > you. RThey propose angling the sial to alter the thrust > vector. Which would be impossible if the momenum transfer was > always in the direction of the photons origional vector. >>You don't seem to have read what I wrote, so I'll repeat it below. > >> A reflected photon transfers momentum to a reflector normal to > >> the reflecting surface. We seem to have a com error here. From your previous statments it sounded like you beleaved all thrust would be in the direction of the origional light sources and that you couldn't divert some of the thrust into a lateral force. I.E. cut the forward thrust down. I never sugested you could reverse thrust on a light sail. Part of the problem on my end might have been my use of a light sail as an example. With a light sail you don't thrust away from the sun. You thrust laterally to slow down or speed up along your orbit vector. Kelly From popserver Mon Nov 27 06:13:06 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1130" "Sun" "26" "November" "1995" "22:46:36" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "24" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA29967; Sun, 26 Nov 95 19:46:30 PST Received: by emout06.mail.aol.com (8.6.12/8.6.12) id WAA04896; Sun, 26 Nov 1995 22:46:36 -0500 Message-Id: <951126224630_34897228@emout06.mail.aol.com> X-UIDL: 817452572.004 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sun, 26 Nov 1995 22:46:36 -0500 ReplyTo : Kelly ReplyFrom : Timothy >I agree that we are stuck without a new power source. Kevins microwave >system or my Externally fueled system are at best theoretical possibilities, >with no real credible way to build them. >> Externally fueled did that mean scooping? I'm not sure >> anymore, please tell me if my assumption is right. Not quite. In my Exporer ship design I assumed the fusion fuel was launched ahead of the ship with a linear accelerator. As the ship accelerates it contiually scoops up pre launched fuel going at nearly its speed. So the ship looses very little momentum scooping up the fuel packets. That would allow you to get up to light speed with "only" 200 times the ships mas in fusion fuel. However like Kevins system. We have a serious problem stoping. I though using a ramscope to produce a lot of drag might do it, but never found a good woorkup of the numbers. By the way. Did anyone calculate the drag on the sail structure from interstelar debre? If you can maintain enough of an electric charge to use the microwave sail as a parachute that might help with stoping. Kelly From popserver Mon Nov 27 06:13:09 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3115" "Sun" "26" "November" "1995" "22:46:54" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951126224644_34897493@emout05.mail.aol.com>" "60" "Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA00132; Sun, 26 Nov 95 19:47:33 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id WAA21838; Sun, 26 Nov 1995 22:46:54 -0500 Message-Id: <951126224644_34897493@emout05.mail.aol.com> X-UIDL: 817452572.005 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org Cc: T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Summarry of the momentum wars and idea. Date: Sun, 26 Nov 1995 22:46:54 -0500 Ok, I'm geting lost in all these cascading arguments and equations. So to try to make sure we have an agreement, I'll try to sumarize. A beam of microwave photons headed in the direction of the ship hits a conical set of mesh sails. Because of the shallow angle of the sails, the photons bounce off the sail moving inward. Because of the shallow angle most of the resulting thrust vector is pointing outward and is canceled out by the oposite side of the sail (I.E. most of the thrust on the sail, or momentum if you prefer is concerted to a thrust load on the sail. No velocity change to ship or sail.), the remaining foward part of the thrust vector does push the ship forward, but at reduced levels. At this point the photons are moving forward and inward toward the ships axis. (Some energy and/or momentum was lost in the first reflection.) This photon stream them hits a power converter, or waveguide feed into the engines or something. At the point of the interaction it still has most its velocity in a forward vector, and about all we've done is cut this amount down due to reflections and power loses as it attempted to rip apart the sail. Are we all agreed on this? Question. Diverted beams of photons converge on a forward pointing cone. This (not considering the beam cancelation due to interfearence, reflection loses, and other such nonsence) is the origional beam moving forward in a much more concentrated form than its pre sail moments. Net thrust to the ship near zip (give or take). In frount of this stream we put an ionized reaction mass. Beam slams into it and throws it forward. A) A lot of the beam (most?) would reflect back off the ionized reaction mass (micro-waves do that off ionized matter) Would this act as Forward's sacrificial outer-sail in "Dragons egg (?)"? I.E. could we use the forwardly reflected beam for drive power? Efectivly the reaction mass (now renamed plasma reflection mass) has gotten boosted forward at a hellish speed, but bounced the beam back down our throats. (Just like Forwards outer drop sail.) We would have to continuously replenish this "reflection mass", but on the bright side we could be very sure it will clean all the interstellar mass out from in frount of the ship. ;) B) Instead of just dumping this superheated reflect mass forward. How about using it as a rocket stream also. At the least we can ride the expanding shock wave from the stuff. Anyway, between A & B we have used part of the beam to create a high temp plasma thurst, and reflected the rest off said plasma onto a rearwardly reflective part of the ship. Momentum/kinetic energy interactions between the beam and the ship are pretty much canceled out until it hits the reaction/reflection mass. The ship needs NO POWER CONVERTERS! We never convert it to electricity to drive an accelerator. (Ok, ok, we convert a little to run the ship and power the magnetic feilds that keep the plasma off the back of the ship.) But other than that, we just reflect it around and feed it mass. Thoughts? (or are we still arguing about momentum and such?) Kelly From popserver Mon Nov 27 08:07:48 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3869" "Mon" "27" "November" "1995" "00:05:31" "-0800" "Steve VanDevender" "stevev@efn.org" nil "77" "Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA09753; Mon, 27 Nov 95 00:02:21 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id AAA12825; Mon, 27 Nov 1995 00:05:31 -0800 Message-Id: <199511270805.AAA12825@tzadkiel.efn.org> In-Reply-To: <951126224644_34897493@emout05.mail.aol.com> References: <951126224644_34897493@emout05.mail.aol.com> X-UIDL: 817459469.000 From: Steve VanDevender To: KellySt@aol.com Cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 00:05:31 -0800 KellySt@aol.com writes: > Ok, I'm geting lost in all these cascading arguments and > equations. So to try to make sure we have an agreement, I'll > try to sumarize. If you can't stand the math get out of the physics. > A beam of microwave photons headed in the direction of the > ship hits a conical set of mesh sails. Because of the shallow > angle of the sails, the photons bounce off the sail moving > inward. Because of the shallow angle most of the resulting > thrust vector is pointing outward and is canceled out by the > oposite side of the sail (I.E. most of the thrust on the sail, > or momentum if you prefer is concerted to a thrust load on the > sail. No velocity change to ship or sail.), the remaining > foward part of the thrust vector does push the ship forward, > but at reduced levels. > > At this point the photons are moving forward and inward toward > the ships axis. (Some energy and/or momentum was lost in the > first reflection.) This photon stream them hits a power > converter, or waveguide feed into the engines or something. > At the point of the interaction it still has most its velocity > in a forward vector, and about all we've done is cut this > amount down due to reflections and power loses as it attempted > to rip apart the sail. > > Are we all agreed on this? Something that I don't think everyone is grasping in these so-called "momentum wars" is that momentum is a vector quantity, not a scalar quantity. That means that two momentum vectors with identical magnitudes that point in different directions are different quantities of momentum, and one momentum vector cannot be converted to the other. You can redirect a photon beam laterally by reflection. By changing the beam's direction, the reflector must develop momentum to conserve the original quantity that the photon beam had before the reflection. I think even those of us who are doing the right things with momentum conservation are confusing others by erroneously saying that the reflected beam has the same momentum as the original beam. It does not, because the reflected beam is traveling in a different direction. You simply cannot change the total quantity of momentum in a system, ever. A piece of the system can change its momentum by exchanging momentum with other pieces, but no matter what it does it cannot change the sum of the momenta of all the pieces. So the simple physical constraint in the system consisting of the photon beam and the spaceship is that the total momentum of the beam and ship remains the same before, during, and after _any_ interaction between them. If the ship is to absorb the photon beam, it _must_ absorb the momentum too. Besides not treating momentum as a vector quantity, people are making the mistake of thinking that lateral loading of the sail assembly is a magical sink for momentum or energy. The error is in thinking that stress on a static structure absorbs energy or momentum continuously over time. If the sail does not move relative to the ship, then it cannot absorb or dissipate momentum separately from the ship. It cannot absorb momentum if it does not move, because momentum means motion. For just an instant, once, when the beam first touches the sail, the beam does work on the static structure to stretch the sail and support members, which absorb a small quantity of energy. From that point on, as long as the sail does not fall apart or the support members do not break, no more energy is dissipated into loading of the sail structure. The reality that static stress does not continue to dissipate energy over time is not intuitive, because our muscles aren't static structures like boards or rods or wires; they must dissipate energy even to hold a weight motionless above your head, while a table holding the same weight does not dissipate energy. From popserver Mon Nov 27 19:07:15 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["506" "Mon" "27" "November" "1995" "11:25:05" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "21" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA28268; Mon, 27 Nov 95 09:24:55 PST Received: by maroon.tc.umn.edu; Mon, 27 Nov 95 11:25:06 -0600 In-Reply-To: <199511270805.AAA12825@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817499001.017 From: Kevin C Houston To: Steve VanDevender Cc: KellySt@aol.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 11:25:05 -0600 (CST) to:all Re; Finals week. I don't think I'll be contribiting too much in the next week or so, but I'll be listening. quick notes. the "momentum" happens every second, so it's actually an acelleration. many structures (static tho they be) resist continuous acceleration all the time by providing opposing compressive or tensile forces rocket equation units should have units of Kg/sec, because that is a mass flow rate. parasail formulas a=.... are units of acelleration. that's all for now. Kevin From popserver Mon Nov 27 21:37:26 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1172" "Mon" "27" "November" "1995" "12:00:59" "-0800" "Steve VanDevender" "stevev@efn.org" nil "35" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA08629; Mon, 27 Nov 95 11:57:45 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id MAA17208; Mon, 27 Nov 1995 12:00:59 -0800 Message-Id: <199511272000.MAA17208@tzadkiel.efn.org> In-Reply-To: References: <199511270805.AAA12825@tzadkiel.efn.org> X-UIDL: 817508043.000 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 12:00:59 -0800 Kevin C. Houston writes: > the "momentum" happens every second, so it's actually an acelleration. That won't get you out of conservation of momentum. The system must change momentum per unit time to equal the amount of momentum added per unit time. > many structures (static tho they be) resist continuous acceleration all > the time by providing opposing compressive or tensile forces The opposing forces are some finite amount of energy that is loaded into the system once. Once the structure is loaded it does not absorb any more energy. If a static structure had to dissipate energy continuously to remain standing, where would such energy come from? Why doesn't your house fall down? Where are the batteries? > rocket equation units should have units of Kg/sec, because that is a mass > flow rate. The equation I was talking about: Me=G*(Ms+Mf) * gamma/(Ve *C) where Ve is exhaust Velocity expressed as a fraction of C. Me is Exhaust Mass. Ms is ship's Mass. Mf is Reaction Mass. G is ship's acceleration. gamma is SQRT(1 - Ve^2 It is inconsistent since it has units of mass on the left, units of mass/time on the right. From popserver Mon Nov 27 21:37:37 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["2454" "Mon" "27" "November" "1995" "14:22:24" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "69" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA10318; Mon, 27 Nov 95 12:24:36 PST Received: by maroon.tc.umn.edu; Mon, 27 Nov 95 14:22:28 -0600 In-Reply-To: <199511272000.MAA17208@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817508043.008 From: Kevin C Houston To: Steve VanDevender Cc: Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 14:22:24 -0600 (CST) On Mon, 27 Nov 1995, Steve VanDevender wrote: > Kevin C. Houston writes: > > the "momentum" happens every second, so it's actually an acelleration. > > That won't get you out of conservation of momentum. The system > must change momentum per unit time to equal the amount of > momentum added per unit time. > > > many structures (static tho they be) resist continuous acceleration all > > the time by providing opposing compressive or tensile forces > > The opposing forces are some finite amount of energy that is > loaded into the system once. Once the structure is loaded it > does not absorb any more energy. > > If a static structure had to dissipate energy continuously to > remain standing, where would such energy come from? Why doesn't > your house fall down? Where are the batteries? good question, it actually proves my point. consider the following experiment. (easy enough to do in reality, but a thought exp here.) take a flat plate. punch three holes equally spaced along the perimeter. attach a piece of wire to each hole and suspend it from the ceiling. shoot (or drop) a lot of ball bearings onto the plate. provided the wires don't break, the bb's encounter the plate from above, but leave it (in all directions) to the side. since bb's eneter the control volume every second, and leave only from the sides, the plate "feels" a net downward force. provided the force does not overcome the wires tensile strength, this situation is stable. where does the energy come from? nowhere, since there is no net loss of momentum, only a change in y for a given change in x. While this gedenkanexperiment proves your point on photon thrust, (i.e. the bb's changed course) it also proves my point on tensile forces. (the wires don't break) > > > rocket equation units should have units of Kg/sec, because that is a mass > > flow rate. > > The equation I was talking about: > > Me=G*(Ms+Mf) * gamma/(Ve *C) > > where > Ve is exhaust Velocity expressed as a fraction of C. > Me is Exhaust Mass. > Ms is ship's Mass. > Mf is Reaction Mass. > G is ship's acceleration. > gamma is SQRT(1 - Ve^2 > > It is inconsistent since it has units of mass on the left, units > of mass/time on the right. > Sorry, I was unclear. Me has units of mass/second since it is the mass flow per unit time. if my gamma is unconventional, I will gladly change. it makes no difference to me. Kevin From popserver Mon Nov 27 22:23:18 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3039" "Mon" "27" "November" "1995" "14:20:15" "-0800" "Steve VanDevender" "stevev@efn.org" nil "58" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA17485; Mon, 27 Nov 95 14:16:59 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id OAA17530; Mon, 27 Nov 1995 14:20:15 -0800 Message-Id: <199511272220.OAA17530@tzadkiel.efn.org> In-Reply-To: References: <199511272000.MAA17208@tzadkiel.efn.org> X-UIDL: 817510794.001 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 14:20:15 -0800 Kevin C. Houston writes: > > The opposing forces are some finite amount of energy that is > > loaded into the system once. Once the structure is loaded it > > does not absorb any more energy. > > > > If a static structure had to dissipate energy continuously to > > remain standing, where would such energy come from? Why doesn't > > your house fall down? Where are the batteries? > > good question, it actually proves my point. consider the following > experiment. (easy enough to do in reality, but a thought exp here.) > > take a flat plate. punch three holes equally spaced along the perimeter. > attach a piece of wire to each hole and suspend it from the ceiling. > shoot (or drop) a lot of ball bearings onto the plate. > provided the wires don't break, the bb's encounter the plate from above, > but leave it (in all directions) to the side. > since bb's eneter the control volume every second, and leave only from > the sides, the plate "feels" a net downward force. > provided the force does not overcome the wires tensile strength, this > situation is stable. where does the energy come from? nowhere, since > there is no net loss of momentum, only a change in y for a given change > in x. > > While this gedenkanexperiment proves your point on photon thrust, > (i.e. the bb's changed course) it also proves my point on tensile > forces. (the wires don't break) Your experiment works as it does only because the momentum from the ball bearings is transferred into the structure that supports the plate, and because you're not including that structure in your "control volume", you're not properly accounting for the momentum of the system. If you do this in space by shooting ball bearings at a plate attached by wires to another structure, the plate and the structure will acquire momentum and start moving as the ball bearings bounce off the plate. The principle of conservation of momentum that has stood since Newton (and that was not modified by Einstein) is tricky to apply in everyday life, because there are a lot of things that complicate it when you're living in an atmosphere on a planet with materials that have friction. When you jump off the ground, the ground also moves away from you under your feet, although by a factor of 10^-23 less (you mass maybe 60 kg; the Earth masses 6e24 kg). When you raise the ball bearings up to drop them on the plate, the center of mass of the Earth moves downward just a tiny amount to compensate. When you drop the bearings, the center of mass of the Earth moves back up, and counterbalances the momentum gained by the plate attached by wires to the structure that is sitting on the Earth. Because this movement is practically unmeasurable, it's easy to ignore it as you did. In a vacuum, in zero gravity, without huge masses that make small changes in momentum unmeasurable, we have conservation of momentum the way Newton imagined it, pure and clean and simple. For every action there is an equal and opposite reaction. From popserver Mon Nov 27 22:28:24 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1495" "Mon" "27" "November" "1995" "14:20:12" "-0800" "Steve VanDevender" "stevev@efn.org" nil "32" "Eureka! We've invented the reactionless drive!" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA17478; Mon, 27 Nov 95 14:16:57 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id OAA17529; Mon, 27 Nov 1995 14:20:12 -0800 Message-Id: <199511272220.OAA17529@tzadkiel.efn.org> In-Reply-To: <199511270805.AAA12825@tzadkiel.efn.org> References: <951126224644_34897493@emout05.mail.aol.com> <199511270805.AAA12825@tzadkiel.efn.org> X-UIDL: 817511101.000 From: Steve VanDevender To: Steve VanDevender Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Eureka! We've invented the reactionless drive! Date: Mon, 27 Nov 1995 14:20:12 -0800 Kevin's invention of a momentum-absorbing structure will be one of the great inventions of history, if it pans out. That's because it could be used to create a reactionless drive. Put Kevin's parasail and a powerful laser inside your ship, and just shine the laser at the parasail. You'll start moving in the direction opposite the direction the laser is pointing. The structure doesn't have to be exposed to space or anything; you could just have a box in the engine room containing the parasail-laser assembly. You can even use the parasail's absorber to power the laser (with some auxiliary generator to compensate for inefficiency losses). Here's what would happen: The laser turns on, and generates forward momentum in the ship in reaction to the backward momentum of the laser light. The laser light is absorbed by the parasail, producing some smaller amount of backward momentum than the forward momentum the ship got in reaction to the laser. There's more forward momentum than backward momentum, so the box produces net forward momentum without reaction mass. A lower-tech solution could involve a bunch of BB cannons shooting at a more sturdy version of the parasail assembly. The best part is that if the parasail recovers most of the energy directed at it, you can keep pumping that energy back in to the laser or BB cannons or whatever is providing the thrust; if you can make this efficient enough, you can get huge amounts of momentum for small quantities of energy. From popserver Tue Nov 28 02:05:36 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1187" "Mon" "27" "November" "1995" "17:28:48" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "27" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from wolfe.net (mail1.wolfe.net) by efn.efn.org (4.1/smail2.5/05-07-92) id AA29591; Mon, 27 Nov 95 17:21:13 PST Received: from sea-ts2-p50.wolfenet.com (sea-ts2-p50.wolfenet.com [204.157.98.168]) by wolfe.net (8.7/8.7) with SMTP id RAA01699; Mon, 27 Nov 1995 17:28:48 -0800 (PST) Message-Id: <199511280128.RAA01699@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817524126.003 From: rddesign@wolfenet.com To: Steve VanDevender Cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 27 Nov 1995 17:28:48 -0800 (PST) >KellySt@aol.com writes: > > > Ok, I'm geting lost in all these cascading arguments and > > equations. So to try to make sure we have an agreement, I'll > > try to sumarize. > >If you can't stand the math get out of the physics. > Ric writes: I have never even dreamed of ever understanding the physics of this but let me toss some stuff out from a dummy's view point. The impression I'm getting is that we can send the power to get us to TC but we can't stop. Correct? How about a hermaphrodite ship. We load it up with reaction mass and hold it in reserve. At mid point we turn the ship, (I know, I know, we've been over this before.) We furl the sail first. ( how we do this is the engineers problem) Turn the ship, begin tossing the reaction mass in the ram and begin the slowing process. As we get nearer to TC unfurl the sail and begin using TC as well as the reaction mass to help slow the ship. I just don't see how many times we can keep running around this topic until we see that with our present technology we don't have too many other choices. OK, guys tear it apart. :-) ( God how I love being canon fodder) The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Tue Nov 28 07:42:09 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["2783" "Mon" "27" "November" "1995" "22:10:43" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "59" "one question" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA10541; Mon, 27 Nov 95 20:39:56 PST Received: by maroon.tc.umn.edu; Mon, 27 Nov 95 22:10:45 -0600 In-Reply-To: <199511280128.RAA01699@wolfe.net> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817544315.006 From: Kevin C Houston To: rddesign@wolfenet.com Cc: Steve VanDevender , stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: one question Date: Mon, 27 Nov 1995 22:10:43 -0600 (CST) Steve, I have a question for you. (BTW, Your sarcasm on the reactionless drive was not lost on me. I am both overjoyed, and dismayed to have invented it overjoyed for obvious reasons. dismayed, because it cannot be --- although E E "Doc" Smith didn't think so ;) Out in intergalactic space (far far away from all outside gravitational influences) you have the following setup: black plate absorbs laser beam ^ p= E/C | _________ | : : | | : : | | :L: | | :A: | # - Laser source | :S: | : - Laser beam | :E: | | - wires to hold plates | :R: | | : : | | : : | | : : | | : : | | ### | | ### | | ### | --------- p= E/C | V The top plate (the absorber) is in thermal equilibrium with a large amount of solid Unobtainium m.p. 2.7 K, atomic mass = sqrt(-1) g/cm^3 so that there is no radiation from heat effects. power is provided by a small on-board power source What happens when you turn on the laser? I'd say that it would just sit there, although you can clearly see that without the wires to hold them together, the laser source and the top plate would to move away from each other. The wires are clearly dissipating a momentum equal to 2 E/C. that is what i was trying to say with my bb analogy. i do have an idea now for a reactionless drive. (inspired by your sarcastic post) It is late at night, and i must get some rest. i will have to post it on the web, as ascii art is not of sufficient resolution to describe it fully. I cannot see why it shouldn't work, Hopefully you will be able to explain. I'll let you all know when it's ready. Kevin H. From popserver Tue Nov 28 08:07:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["7164" "Tue" "28" "November" "1995" "09:05:22" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199511280805.AA25072@student.utwente.nl>" "160" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA19885; Tue, 28 Nov 95 00:04:11 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA25072 (5.67b/IDA-1.5 for ); Tue, 28 Nov 1995 09:05:15 +0100 Message-Id: <199511280805.AA25072@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817545868.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Tue, 28 Nov 1995 09:05:22 +0100 ReplyTo : Kelly ReplyFrom : Timothy >>> Externally fueled did that mean scooping? I'm not sure >>> anymore, please tell me if my assumption is right. > >Not quite. In my Exporer ship design I assumed the fusion fuel was launched >ahead of the ship with a linear accelerator. As the ship accelerates it >contiually scoops up pre launched fuel going at nearly its speed. So the >ship looses very little momentum scooping up the fuel packets. That would >allow you to get up to light speed with "only" 200 times the ships mas in >fusion fuel. However like Kevins system. We have a serious problem stoping. > I though using a ramscope to produce a lot of drag might do it, but never >found a good woorkup of the numbers. This method of prelaunching fuel packets will cost the same amount of energy that is needed if you take those same packets with you from the start. Why? Because all packets have the same speed as the Asimov after it has accelerated. Accelerating a lot of small packets or just one big packet does not save energy. >By the way. Did anyone calculate the drag on the sail structure from >interstelar debre? If you can maintain enough of an electric charge to use >the microwave sail as a parachute that might help with stoping. The problem is that there are no accurate numbers of the density of interstellar debris. So any number is almost a guess. =============================================================================== ReplyTo : Steve ReplyFrom : Timothy >In a frame where the ship is in motion, the photon changes energy >when it bounces off the ship; its reflected energy is less than >the incident energy if the ship receding, greater if the ship is >approaching. You actually were right to compare this to doppler >radar, because it's this effect that doppler radar measures to >determine velocity. Huh, are you saying I was right the first time? Am I right saying the following: Photons loose energy because they accelerate the car. Only because of that acceleration their frequency is lowered. Because it takes more energy to transfer the same amount of momentum to a faster moving car (E=v^2 versus p=v) the frequency is lowered even more. >Mass is a more subtle concept than energy; while energies add >linearly, masses as magnitudes of momenergy vectors do not. Agreed. > > I would conclude from this that moving bodies excert greater gravitation > > either because of gain of mass or gain of energy. I feel both can be used, > > its a bit like the wave-particle duality. > >What I really want to see is the general relativistic formula >that says whether spacetime curvature is the result of an >object's mass or its energy. It's hard to find such a formula, all books about general relativistics use tensor calculus. I have a hard time understanding them, so I don't know much about formulas in general relativistics. But don't think we need this formula any more: In Taylor & Wheelers terminology I think curvature would be the result of energy. In "more" general terms it would be either the result of its relativistic mass or the result of its rest mass AND its kinetic energy (ie. together the total energy). > > >> Is it this translation of energy to mass that gives the trouble? > > > > > >It is that my studies of relativistic kinematics do not allow for > > >the treatment of energy and mass as identical quantities. > > > > They are indeed not identical but equivalent, meaning they can be be > > interchanged. > >Not in Taylor and Wheeler's terminology. The only time they >allow mass and energy to be spoken of as equivalent is when you >are dealing with an object in its rest frame. In any other frame >the object's energy is not equivalent to its mass. No indeed not equivalent to its rest mass but equivalent to its relativistic mass. >>>> I say that "relativistic mass increase" is a misnomer and that >>>> you are better off treating mass as invariant. I guess that is what I always did, only I was not that much aware of the problems others might have with the duality in the terminology. After all this, can we conclude a charged battery is heavier than an uncharged battery? ================================================================================ ReplyTo : Kelly ReplyFrom : Timothy >Question. >Diverted beams of photons converge on a forward pointing cone. This (not >considering the beam cancelation due to interfearence, reflection loses, and >other such nonsence) is the origional beam moving forward in a much more >concentrated form than its pre sail moments. Net thrust to the ship near zip >(give or take). In frount of this stream we put an ionized reaction mass. > Beam slams into it and throws it forward. > >A) A lot of the beam (most?) would reflect back off the ionized reaction mass >(micro-waves do that off ionized matter) Would this act as Forward's >sacrificial outer-sail in "Dragons egg (?)"? I.E. could we use the forwardly >reflected beam for drive power? Efectivly the reaction mass (now renamed >plasma reflection mass) has gotten boosted forward at a hellish speed, but >bounced the beam back down our throats. (Just like Forwards outer drop >sail.) We would have to continuously replenish this "reflection mass", but >on the bright side we could be very sure it will clean all the interstellar >mass out from in frount of the ship. ;) Replenishing the "mirror" will probably take lots of ions or in other words mass that has to be taken with us. Also using such a light (non heavy) sail will mean that the "mirror" is accelerated a lot and lot of energy is lost due to the Doppler effect. Also I have doubts how well the "mirror" reflects, ionized particles attract or repell each other so, it won't take long befor the "mirror" has destroyed itself. >B) >Instead of just dumping this superheated reflect mass forward. How about >using it as a rocket stream also. At the least we can ride the expanding >shock wave from the stuff. Shock wave? I don't understand, please explain again. >Anyway, between A & B we have used part of the beam to create a high temp >plasma thurst, and reflected the rest off said plasma onto a rearwardly >reflective part of the ship. Momentum/kinetic energy interactions between >the beam and the ship are pretty much canceled out until it hits the >reaction/reflection mass. The ship needs NO POWER CONVERTERS! We never >convert it to electricity to drive an accelerator. (Ok, ok, we convert a >little to run the ship and power the magnetic feilds that keep the plasma off >the back of the ship.) But other than that, we just reflect it around and >feed it mass. ============================================================================== Steve writes: >The reality that static stress does not continue to dissipate >energy over time is not intuitive, because our muscles aren't >static structures like boards or rods or wires; they must >dissipate energy even to hold a weight motionless above your >head, while a table holding the same weight does not dissipate >energy. Yes, in fact is does not take any energy to keep floating a few metres above Earth's surface. Timothy From popserver Tue Nov 28 12:11:34 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2934" "Tue" "28" "November" "1995" "00:52:06" "-0800" "Steve VanDevender" "stevev@efn.org" nil "67" "one question" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA03323; Tue, 28 Nov 95 04:07:37 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id AAA19367; Tue, 28 Nov 1995 00:52:06 -0800 Message-Id: <199511280852.AAA19367@tzadkiel.efn.org> In-Reply-To: References: <199511280128.RAA01699@wolfe.net> X-UIDL: 817560468.008 From: Steve VanDevender To: Kevin C Houston Cc: rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: one question Date: Tue, 28 Nov 1995 00:52:06 -0800 Kevin C. Houston writes: > Steve, I have a question for you. (BTW, Your sarcasm on the > reactionless drive was not lost on me. I am both overjoyed, and dismayed > to have invented it overjoyed for obvious reasons. dismayed, because it > cannot be --- although E E "Doc" Smith didn't think so ;) I hope it did not seem harsh. My intent was to demonstrate a really nifty application for your, um, incredible invention. :-) > Out in intergalactic space (far far away from all outside gravitational > influences) you have the following setup: [ Figure turned sideways for brevity -- top -> ] |--------------------------------------| |######~~~~~~~~~~~~~~~~~~~~~~~~ | p = -E/c |######~~~~~L~A~S~E~R~~~~~~~~~~ | p = E/c |######~~~~~~~~~~~~~~~~~~~~~~~~ | |--------------------------------------| black plate absorbs laser beam # = laser ~ = laser beam - = support wires > The top plate (the absorber) is in thermal equilibrium with a large > amount of solid Unobtainium m.p. 2.7 K, atomic mass = sqrt(-1) g/cm^3 > so that there is no radiation from heat effects. power is provided by a > small on-board power source You must shop at the same physics experiment supply store that I do. That unobtainium sure is useful :-). > What happens when you turn on the laser? > > I'd say that it would just sit there, although you can clearly see that > without the wires to hold them together, the laser source and the top > plate would to move away from each other. You are correct. Although an actual device like this would actually move, but not with any permanent velocity. As the laser heats the absorption plate, mass is transferred from the laser to the plate. As the center of gravity shifts to the right (in my diagram) the assembly would slide to the left. When the laser is turned off, it would stop, then begin to slide slowly rightward as the plate reheats the laser by radiation. > The wires are clearly dissipating a momentum equal to 2 E/C. > that is what i was trying to say with my bb analogy. I'm not sure "dissipating momentum" is quite the term for it. After all, the laser with momentum -E/c is tugging through the wires against the plate with momentum E/c. The momenta cancel. Like I said before, momentum means motion. A non-moving object has no momentum. If the laser and the plate are held together with wires and don't move relative to each other or your observer, then you can't say that they have momentum. The wires are indeed under tension, because there is a force between the laser and the plate. This tension was created in the first instant the laser was turned on, and a small amount of its energy went into stretching the wires before it was all spent on heating the plate. From popserver Tue Nov 28 15:55:30 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["3150" "Tue" "28" "November" "1995" "09:04:41" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "86" "Re: one question" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA09333; Tue, 28 Nov 95 07:02:46 PST Received: by maroon.tc.umn.edu; Tue, 28 Nov 95 09:04:42 -0600 In-Reply-To: <199511280852.AAA19367@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817573904.011 From: Kevin C Houston To: Steve VanDevender Cc: rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: one question Date: Tue, 28 Nov 1995 09:04:41 -0600 (CST) On Tue, 28 Nov 1995, Steve VanDevender wrote: > Kevin C. Houston writes: > > > Out in intergalactic space (far far away from all outside gravitational > > influences) you have the following setup: > > [ Figure turned sideways for brevity -- top -> ] Fine with me. > > > |--------------------------------------| > |######~~~~~~~~~~~~~~~~~~~~~~~~ | > p = -E/c |######~~~~~L~A~S~E~R~~~~~~~~~~ | p = E/c > |######~~~~~~~~~~~~~~~~~~~~~~~~ | > |--------------------------------------| > black plate > absorbs laser beam > # = laser > ~ = laser beam > - = support wires > > > The top plate (the absorber) is in thermal equilibrium with a large > > amount of solid Unobtainium m.p. 2.7 K, atomic mass = sqrt(-1) g/cm^3 > > so that there is no radiation from heat effects. power is provided by a > > small on-board power source > > You must shop at the same physics experiment supply store that I > do. That unobtainium sure is useful :-). > > > What happens when you turn on the laser? > > > > I'd say that it would just sit there, although you can clearly see that > > without the wires to hold them together, the laser source and the top > > plate would to move away from each other. > > You are correct. > > Although an actual device like this would actually move, but not > with any permanent velocity. As the laser heats the absorption that's the reson for the unobtainium, the melting never shifts above cosmic backround radiation level > plate, mass is transferred from the laser to the plate. As the > center of gravity shifts to the right (in my diagram) the > assembly would slide to the left. When the laser is turned off, > it would stop, then begin to slide slowly rightward as the plate > reheats the laser by radiation. > > > The wires are clearly dissipating a momentum equal to 2 E/C. > > that is what i was trying to say with my bb analogy. > > I'm not sure "dissipating momentum" is quite the term for it. > After all, the laser with momentum -E/c is tugging through the > wires against the plate with momentum E/c. The momenta cancel. > YES! That's what I've been saying all along! that a physical structure can transmit (through tugging) opposite momenta that can then cancel! > Like I said before, momentum means motion. A non-moving object > has no momentum. If the laser and the plate are held together > with wires and don't move relative to each other or your > observer, then you can't say that they have momentum. The laser imparts momentum when it leaves, and when it strikes the black plate. > > The wires are indeed under tension, because there is a force > between the laser and the plate. This tension was created in the > first instant the laser was turned on, and a small amount of its > energy went into stretching the wires before it was all spent on > heating the plate. > so you're saying that the plate heats more if it is held in place than if it was free to move? Kevin From popserver Tue Nov 28 22:13:51 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["444" "Tue" "28" "November" "1995" "18:09:43" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199511281709.AA18223@student.utwente.nl>" "9" "Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA15729; Tue, 28 Nov 95 09:08:23 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA18223 (5.67b/IDA-1.5 for ); Tue, 28 Nov 1995 18:09:39 +0100 Message-Id: <199511281709.AA18223@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817596604.006 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Physics store Date: Tue, 28 Nov 1995 18:09:43 +0100 Hey, Steve and Kevin can one of you give me the address of that special physics supply store? I can't find one in the yellow pages. I'd like to shop there and try to find an anti-gravity/anti-inertia device. Such a device would be most useful. No bulky engines, only small amounts of energy needed. Even high acceleration would not be a problem because our muscles would have the same strength but our bodies would have less inertia. Timothy From popserver Tue Nov 28 22:13:55 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["868" "Tue" "28" "November" "1995" "12:01:53" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "22" "Re: Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA18479; Tue, 28 Nov 95 10:03:09 PST Received: by maroon.tc.umn.edu; Tue, 28 Nov 95 12:01:54 -0600 In-Reply-To: <199511281709.AA18223@student.utwente.nl> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817596604.010 From: Kevin C Houston To: Timothy van der Linden Cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Physics store Date: Tue, 28 Nov 1995 12:01:53 -0600 (CST) On Tue, 28 Nov 1995, Timothy van der Linden wrote: > Hey, Steve and Kevin can one of you give me the address of that special > physics supply store? I can't find one in the yellow pages. I'd like to shop > there and try to find an anti-gravity/anti-inertia device. > Such a device would be most useful. No bulky engines, only small amounts of > energy needed. Even high acceleration would not be a problem because our > muscles would have the same strength but our bodies would have less inertia. > > Timothy > > Sure, no problem. I can't remember the exact address, but the directions are easy enough. Go down to the nearest corner. Take any street to be direction 'x', take the perpendicular street to be 'y', take the vertical direction to be 'z', now go two blocks in any direction that is perpendicular to 'x','y' _and_ 'z'. you can't miss it. %^) From popserver Tue Nov 28 22:14:00 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["540" "" "28" "November" "1995" "13:56:20" "-0500" "jim@bogie2.bio.purdue.edu" "jim@bogie2.bio.purdue.edu" nil "17" "Re(2) Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from sage.cc.purdue.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA22151; Tue, 28 Nov 95 11:01:09 PST Received: from bogie2.bio.purdue.edu (bogie2.bio.purdue.edu [128.210.65.16]) by sage.cc.purdue.edu (8.6.10/8.6.12) with SMTP id NAA29371; Tue, 28 Nov 1995 13:53:48 -0500 Message-Id: X-UIDL: 817596604.013 From: "jim" To: "KellySt@aol.com" , "Kevin C Houston" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "Timothy van der Linden" , "zkulpa@zmit1.ippt.gov.pl" Subject: Re(2) Physics store Date: 28 Nov 1995 13:56:20 -0500 I believe you mean "Acme Physics Warehouse". There are several, but this has the personal endorsement of Mr. Wile E. Coyote (Super-Genius). In addition to anti-gravity generators, they also do good a business in massless ropes, frictionless pulleys, and infinate lines and planes of charge. Kevin's directions were a bit incomplete, however. The address is as follows: Acme Physics Warehouse Box 3.14 Squared Circle Phone Number : (278) 182-8182 ext. 8 - Jim Cavera (Super-Genius) Sent with CTM PowerMail 1.0 From popserver Tue Nov 28 23:04:48 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4801" "Tue" "28" "November" "1995" "15:00:18" "-0800" "Steve VanDevender" "stevev@efn.org" nil "102" "Re: one question" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA07848; Tue, 28 Nov 95 14:56:53 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id PAA21239; Tue, 28 Nov 1995 15:00:18 -0800 Message-Id: <199511282300.PAA21239@tzadkiel.efn.org> In-Reply-To: References: <199511280852.AAA19367@tzadkiel.efn.org> X-UIDL: 817599675.000 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: one question Date: Tue, 28 Nov 1995 15:00:18 -0800 Kevin C. Houston writes: > > > The wires are clearly dissipating a momentum equal to 2 E/C. > > > that is what i was trying to say with my bb analogy. > > > > I'm not sure "dissipating momentum" is quite the term for it. > > After all, the laser with momentum -E/c is tugging through the > > wires against the plate with momentum E/c. The momenta cancel. > > YES! That's what I've been saying all along! that a physical structure > can transmit (through tugging) opposite momenta that can then cancel! I thought about deleting that paragraph ("I'm not sure 'dissipating momentum' . . . ") because it's not really consistent with my position that you only have momentum if you have motion. If the things don't move, they don't have momentum, or absorb momentum, or dissipate momentum. What I was really objecting to in your parasail design was not the idea that you had cancelling momenta, but that you thought that creating sideways momentum meant a decrease in forward momentum. For example, a device like this: E/c --v :::: p = [ 0 E/(2*c) ] |----------------------------------:::/| |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::/ | |######~~~~~L~A~S~E~R~~~~~~~~~~~~~~:/ | beam splitter |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~:\ | |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::\ | |----------------------------------:::\| :::: p = [ 0 -E/(2*c) ] # = laser ~ = laser light -- = wires also won't move. The beam splitter "absorbs momentum" just like the black absorbing plate did, even though it splits the beam into two beams traveling in the +y and -y directions. This setup also has the advantage of not requiring an unobtainium heat sink, as long as you get a Perfect Mirror (tm) from Acme Physics Warehouse. Without wires to hold the beam splitter in a fixed position with respect to the laser, it too would move away from the laser. It's critical to understand that momentum is a vector quantity to understand how the beam splitter can move, even though it is emitting two beams whose momentum magnitudes are both p/2 while it is picking up momentum with magnitude p from the laser. Although it is intuitive to think in terms of the magnitudes of the momentum components and then try to add those to account for system momentum, it's unfortunately wrong. Although the laser light carries momentum [ p 0 ] to the unbound beam splitter and the splitter, as a result of reflecting halves of the beam, produces two smaller beams with momentum [ 0 p/2 ] and [ 0 -p/2 ], those two beams add to momentum [ 0 0 ] -- they carry no forward momentum whatsoever; as a pair, they carry no momentum at all. Yet conservation of momentum requires that the total momentum remain [ p 0 ], and the only place this can show up is in the beam splitter itself. Since the beam splitter stopped all forward motion of the beam, it's not even that unintuitive that it should get the forward momentum. The ultimate case of absolutely needing to think of momentum as a vector quantity is when you have an object with zero momentum that splits into two or more objects with nonzero momenta. The vector sum of momenta of all the objects will still be zero, but in a sense momentum did come from nowhere since an unmoving object gave rise to motion. > > Like I said before, momentum means motion. A non-moving object > > has no momentum. If the laser and the plate are held together > > with wires and don't move relative to each other or your > > observer, then you can't say that they have momentum. > > The laser imparts momentum when it leaves, and when it strikes the black > plate. Once, during the time that the beam is in progress to the absrber plate. For much the same reasons that I don't like "relativistic mass", I don't like the notion of imparting momentum to a non-moving object. Clearly it has lead to some incorrect physical thinking. If something can't be put into uniform linear motion relative to something else, then it can't "absorb momentum" relative to that thing. > > The wires are indeed under tension, because there is a force > > between the laser and the plate. This tension was created in the > > first instant the laser was turned on, and a small amount of its > > energy went into stretching the wires before it was all spent on > > heating the plate. > > so you're saying that the plate heats more if it is held in place than if > it was free to move? Yes. If it was free to move, it would acquire velocity; as it acquired velocity, the light it received would become weaker due to doppler-shifting, and so the plate would receive less energy. If it is held in place, then it never has velocity relative to the laser, which always transmits the same energy per unit time to the plate. From popserver Tue Nov 28 23:30:10 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1319" "Tue" "28" "November" "1995" "15:28:18" "-0800" "Steve VanDevender" "stevev@efn.org" nil "25" "Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA09692; Tue, 28 Nov 95 15:24:51 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id PAA21310; Tue, 28 Nov 1995 15:28:18 -0800 Message-Id: <199511282328.PAA21310@tzadkiel.efn.org> In-Reply-To: <199511281709.AA18223@student.utwente.nl> References: <199511281709.AA18223@student.utwente.nl> X-UIDL: 817601196.000 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Physics store Date: Tue, 28 Nov 1995 15:28:18 -0800 Timothy van der Linden writes: > Hey, Steve and Kevin can one of you give me the address of that special > physics supply store? I can't find one in the yellow pages. I'd like to shop > there and try to find an anti-gravity/anti-inertia device. > Such a device would be most useful. No bulky engines, only small amounts of > energy needed. Even high acceleration would not be a problem because our > muscles would have the same strength but our bodies would have less inertia. > > Timothy Others have given you the address of the Acme Physics Warehouse. The stuff you want is probably in the "Cartoon Physics" section; the "Real Physics" section just has stuff like point masses, frictionless surface coatings, and ideal gases. You can do antigravity in several ways. One is to keep a suspended creature permanently in ignorance of its altitude with special blinders; as you know, creatures won't fall until they know they are above a canyon. Another is to surprise a creature, causing it to levitate above the ground, then keep it in that state; you can get boxes of carefully bred mice that are easily surprised. Someone in love will float above the ground, and can be tugged around simply by the scent of the loved one, implying minimal inertia; tailored "love drugs" can be used to induce this state. From popserver Tue Nov 28 23:50:36 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1860" "Tue" "28" "November" "1995" "15:47:04" "-0800" "Steve VanDevender" "stevev@efn.org" nil "43" "Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA10985; Tue, 28 Nov 95 15:43:37 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id PAA21352; Tue, 28 Nov 1995 15:47:04 -0800 Message-Id: <199511282347.PAA21352@tzadkiel.efn.org> In-Reply-To: <199511280805.AA25072@student.utwente.nl> References: <199511280805.AA25072@student.utwente.nl> X-UIDL: 817602415.000 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Tue, 28 Nov 1995 15:47:04 -0800 Timothy van der Linden writes: > Am I right saying the following: > > Photons loose energy because they accelerate the car. Only because of that > acceleration their frequency is lowered. > Because it takes more energy to transfer the same amount of momentum to a > faster moving car (E=v^2 versus p=v) the frequency is lowered even more. There is one important constraint in this situation: photons _always_ have equal momentum and energy; hence a photon reflecting off a moving object must impart equal amounts of momentum and energy to it. A photon has less energy when seen from the frame of a fast-moving object moving in the same direction as the photon, so in the object frame the photon imparts less momentum to the object. Seen from the observer's frame, the photon loses more momentum to a receding fast-moving object than a slow-moving one. Remember that reflecting objects moving opposite to the direction of the incident photons actually impart energy and momentum to the photons; in the object frame the photon has more energy and momentum. > After all this, can we conclude a charged battery is heavier than an > uncharged battery? Yes, this is also true. Hot objects are heavier than cold ones (although not by an amount we have equipment to measure). A mirrored box full of photons is heavier than the empty box. > Steve writes: > >The reality that static stress does not continue to dissipate > >energy over time is not intuitive, because our muscles aren't > >static structures like boards or rods or wires; they must > >dissipate energy even to hold a weight motionless above your > >head, while a table holding the same weight does not dissipate > >energy. > > Yes, in fact is does not take any energy to keep floating a few metres above > Earth's surface. Well, it depends on how you make the object float. From popserver Wed Nov 29 00:00:51 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["512" "Wed" "29" "November" "1995" "00:56:57" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "12" "Re: Re(2) Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA11563; Tue, 28 Nov 95 15:54:14 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15487 (5.67b/IDA-1.5 for ); Wed, 29 Nov 1995 00:56:53 +0100 Message-Id: <199511282356.AA15487@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817603036.001 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Re(2) Physics store Date: Wed, 29 Nov 1995 00:56:57 +0100 Steve, I had a hard time figuring out where to go, fortunately Jim's message reached me before I got lost completely. I talked to Mr. Wile and asked him for the anti-grav. equipment. He told me somebody had been there before me, just one hour earlier and bought the last one. He already had ordered new ones but did not know yet when they would arrive. It was possible to reserve one, so I did. I almost can't wait untill I can use it. When I have got equipment, I will tell you guys more about it... Timothy From popserver Wed Nov 29 05:52:10 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1536" "Tue" "28" "November" "1995" "20:38:55" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951128203350_119181713@emout06.mail.aol.com>" "33" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA17882; Tue, 28 Nov 95 17:37:25 PST Received: by emout06.mail.aol.com (8.6.12/8.6.12) id UAA24591; Tue, 28 Nov 1995 20:38:55 -0500 Message-Id: <951128203350_119181713@emout06.mail.aol.com> X-UIDL: 817624104.001 From: KellySt@aol.com To: stevev@efn.org Cc: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Tue, 28 Nov 1995 20:38:55 -0500 >> Besides not treating momentum as a vector quantity, people are >> making the mistake of thinking that lateral loading of the sail >> assembly is a magical sink for momentum or energy. The error is >> in thinking that stress on a static structure absorbs energy or >> momentum continuously over time. If the sail does not move >> relative to the ship, then it cannot absorb or dissipate momentum >> separately from the ship. It cannot absorb momentum if it does >> not move, because momentum means motion. ---- (??!) Thats like the old argument that if a tractor is pushing against a wall its doing no work, since the wall isn't accelerated. The sail is getting a thrust that is perpendicular to the surface of reflection. If you want to describe the portion of the thrust that isn't accelerating the ship as invalid, enjoy. But when you start to mutter things like: >> ---as long as the sail does not fall apart or the support >> members do not break, no more energy is dissipated into >> loading of the sail structure. We have a problem. A considerable amount of energy will be continuously loaded and (hopefully) disapated by the sail cross webbing. If we don't consider it, and make sure the structure can disapate it, the cross cables will melt under the energy they have to disapate under this lateral thrust load. One very consistent problem in LIT over the last year has been a very limited interest in the engineering realities of a situation, and to much fondness for endless equation wars. Kelly From popserver Wed Nov 29 05:52:32 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["467" "Tue" "28" "November" "1995" "21:52:43" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "13" "Re: Re(2) Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA21876; Tue, 28 Nov 95 18:50:36 PST Received: by emout04.mail.aol.com (8.6.12/8.6.12) id VAA13914; Tue, 28 Nov 1995 21:52:43 -0500 Message-Id: <951128215241_37461372@emout04.mail.aol.com> X-UIDL: 817624104.012 From: KellySt@aol.com To: jim@bogie2.bio.purdue.edu, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: Re(2) Physics store Date: Tue, 28 Nov 1995 21:52:43 -0500 >> I believe you mean "Acme Physics Warehouse". There are >> several, but this has the personal endorsement of Mr. >> Wile E. Coyote (Super-Genius). In addition to >> anti-gravity generators, they also do good a business in >> massless ropes, frictionless pulleys, and infinate lines >> and planes of charge. >> - Jim Cavera (Super-Genius) Hum -- If they have used hydrive, or some of the Star Trek gobbdy gook physics we're in busness!! ;) Kelly Starks From popserver Wed Nov 29 05:52:33 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6330" "Tue" "28" "November" "1995" "21:52:07" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "140" "Re: Engineering Newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail02.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA21944; Tue, 28 Nov 95 18:51:41 PST Received: by mail02.mail.aol.com (8.6.12/8.6.12) id VAA02539; Tue, 28 Nov 1995 21:52:07 -0500 Message-Id: <951128215138_37459926@mail02.mail.aol.com> X-UIDL: 817624104.013 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 28 Nov 1995 21:52:07 -0500 Replyto : Timothy >>> Externally fueled did that mean scooping? I'm not sure >>> anymore, please tell me if my assumption is right. > >Not quite. In my Exporer ship design I assumed the fusion fuel was launched >ahead of the ship with a linear accelerator. As the ship accelerates it >contiually scoops up pre launched fuel going at nearly its speed. So the >ship looses very little momentum scooping up the fuel packets. That would >allow you to get up to light speed with "only" 200 times the ships mas in >fusion fuel. However like Kevins system. We have a serious problem stoping. > I though using a ramscope to produce a lot of drag might do it, but never >found a good woorkup of the numbers. >> This method of prelaunching fuel packets will cost the >> same amount of energy that is needed if you take those >> same packets with you from the start. True, but since the ship doesn't have to supply the energy, it saves an incredable amount of fuel. To put it bluntly no fusion powered ship could carry enough fuel, to accelerate itself and its fuel up to high reletivistic speeds. Estimates are that a ship would need a 1,000,000 to 1 fuel to ship mass ratio to get up to $10 of light speed. But if the ship doesn't have to carry its fuel, a 200 to 1 ratio could get you most of the way to light speed (or was that 1/3rd light speed. Been a while since GES ran the numbers off for me.) >By the way. Did anyone calculate the drag on the sail structure from >interstelar debre? If you can maintain enough of an electric charge to use >the microwave sail as a parachute that might help with stoping. >> The problem is that there are no accurate numbers of >> the density of interstellar debris. So any number is almost >> a guess. Thats been a constand problem for us. How do you design a ship to travel through something you know next to nothing about? ============================================================================== == >Question. >Diverted beams of photons converge on a forward pointing cone. This (not >considering the beam cancelation due to interfearence, reflection loses, and >other such nonsence) is the origional beam moving forward in a much more >concentrated form than its pre sail moments. Net thrust to the ship near zip >(give or take). In frount of this stream we put an ionized reaction mass. > Beam slams into it and throws it forward. > >A) A lot of the beam (most?) would reflect back off the ionized reaction mass >(micro-waves do that off ionized matter) Would this act as Forward's >sacrificial outer-sail in "Dragons egg (?)"? I.E. could we use the forwardly >reflected beam for drive power? Efectivly the reaction mass (now renamed >plasma reflection mass) has gotten boosted forward at a hellish speed, but >bounced the beam back down our throats. (Just like Forwards outer drop >sail.) We would have to continuously replenish this "reflection mass", but >on the bright side we could be very sure it will clean all the interstellar >mass out from in frount of the ship. ;) >> Replenishing the "mirror" will probably take lots of ions >> or in other words mass that has to be taken with us. Agreed, but it don't have a handel on the amount of mass. (Hey it sounds better than Forwards ring sail trick.) >> Also using such a light (non heavy) sail will mean that >> the "mirror" is accelerated a lot and lot of energy is lost >> due to the Doppler effect. Given that the mirror is the surface of a plasma, and said plasma is being continuously being replenished. I'm not sure the reflective "surface" is actually moving? Althou obviously the particals in the plasma are moving (and accelerating) rapidly. Are the micro waves reflecting off the particals? Or off the area where the plasma is ionized enough to reflect them? >> Also I have doubts how well the "mirror" reflects, ionized >> particles attract or repell each other so, it won't take long >> befor the "mirror" has destroyed itself. The ions in a plasma of the same material wil repell each other. You might be able to do some magnetic tricks to hold it, but it probably wouldn't be worth the trouble. [ Hum --- I wounder if you could wiggle the exausting plasma to for a laser to get back some of the energy? ] As to reflectivity. That would depend on the nature of the plasma and a lot of other variables. This is probably not a question we could easily figure out for ourselves. >B) >Instead of just dumping this superheated reflect mass forward. How about >using it as a rocket stream also. At the least we can ride the expanding >shock wave from the stuff. >> Shock wave? I don't understand, please explain again. You have a mass of plasma being hit with E18 of energy. It will be HOT, and highly ionized. It will be explosivly expanding. The light pressure of the beam (or the feed mass) will probably keep it from flowing straight up the beam. But it will be moving rapidly to the sides and forward or the ship. We should be able to tap this for thrust. >Anyway, between A & B we have used part of the beam to create a high temp >plasma thurst, and reflected the rest off said plasma onto a rearwardly >reflective part of the ship. Momentum/kinetic energy interactions between >the beam and the ship are pretty much canceled out until it hits the >reaction/reflection mass. The ship needs NO POWER CONVERTERS! We never >convert it to electricity to drive an accelerator. (Ok, ok, we convert a >little to run the ship and power the magnetic feilds that keep the plasma off >the back of the ship.) But other than that, we just reflect it around and >feed it mass. ============================================================================== Steve writes: >The reality that static stress does not continue to dissipate >energy over time is not intuitive, because our muscles aren't >static structures like boards or rods or wires; they must >dissipate energy even to hold a weight motionless above your >head, while a table holding the same weight does not dissipate >energy. >> Yes, in fact is does not take any energy to keep floating a >> few metres above Earth's surface. (???????!!!!!!) SAY WHAT!! Unless we're on differnt planets you have to generate or disapate as much energy as to generate 9.8 m/s^2 of acceleration. Kelly Starks From popserver Wed Nov 29 05:52:36 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["451" "Tue" "28" "November" "1995" "21:52:58" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "14" "Re: Physics store" "^From:" nil nil "11" nil nil nil nil] nil) Received: from emout04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA22018; Tue, 28 Nov 95 18:52:51 PST Received: by emout04.mail.aol.com (8.6.12/8.6.12) id VAA14173; Tue, 28 Nov 1995 21:52:58 -0500 Message-Id: <951128215251_37461691@emout04.mail.aol.com> X-UIDL: 817624104.014 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl Cc: stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Physics store Date: Tue, 28 Nov 1995 21:52:58 -0500 >> I can't remember the exact address, but the directions >> are easy enough. >> Go down to the nearest corner. Take any street to be >> direction 'x', take the perpendicular street to be 'y', take >> the vertical direction to be 'z', now go two blocks in any >> direction that is perpendicular to 'x','y' _and_ 'z'. you >> can't miss it. %^) {:}-( Kev, I think your finals are starting to get to you. You need to lie down for a while! From popserver Wed Nov 29 05:52:37 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1035" "Tue" "28" "November" "1995" "21:52:14" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951128215159_37460474@mail02.mail.aol.com>" "27" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from mail02.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA21916; Tue, 28 Nov 95 18:53:21 PST Received: by mail02.mail.aol.com (8.6.12/8.6.12) id VAA02638; Tue, 28 Nov 1995 21:52:14 -0500 Message-Id: <951128215159_37460474@mail02.mail.aol.com> X-UIDL: 817624104.015 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org Cc: T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Tue, 28 Nov 1995 21:52:14 -0500 On Mon, 27 Nov 1995, Steve VanDevender wrote: > Kevin C. Houston writes: > > the "momentum" happens every second, so it's actually an acelleration. > > That won't get you out of conservation of momentum. The system > must change momentum per unit time to equal the amount of > momentum added per unit time. > > > many structures (static tho they be) resist continuous acceleration all > > the time by providing opposing compressive or tensile forces > > The opposing forces are some finite amount of energy that is > loaded into the system once. Once the structure is loaded it > does not absorb any more energy. > > If a static structure had to dissipate energy continuously to > remain standing, where would such energy come from? Why doesn't > your house fall down? Where are the batteries? The energy is coming from the gravitational attraction of the earth. It is disapated as heat in the structure of the house. In a structure under heavy loads (too heavy) you can feel the heat in the structure. Kelly Starks From popserver Wed Nov 29 06:03:14 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["680" "Tue" "28" "November" "1995" "22:00:49" "-0800" "Steve VanDevender" "stevev@efn.org" nil "16" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA02264; Tue, 28 Nov 95 21:57:21 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id WAA00313; Tue, 28 Nov 1995 22:00:49 -0800 Message-Id: <199511290600.WAA00313@tzadkiel.efn.org> In-Reply-To: <951128215159_37460474@mail02.mail.aol.com> References: <951128215159_37460474@mail02.mail.aol.com> X-UIDL: 817624769.000 From: Steve VanDevender To: KellySt@aol.com Cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Tue, 28 Nov 1995 22:00:49 -0800 KellySt@aol.com writes: > > If a static structure had to dissipate energy continuously to > > remain standing, where would such energy come from? Why doesn't > > your house fall down? Where are the batteries? > > The energy is coming from the gravitational attraction of the earth. It is > disapated as heat in the structure of the house. In a structure under heavy > loads (too heavy) you can feel the heat in the structure. Really? So when does the earth run out of gravity? I think you've spent too much time in the Cartoon Physics section of Acme Physics Warehouse. Tell me about one of these structures that I can go visit, put my hand on, and feel the heat. From popserver Wed Nov 29 21:34:24 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3975" "Wed" "29" "November" "1995" "11:36:38" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "102" "Re: one question" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA14433; Wed, 29 Nov 95 02:33:53 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA17411 (5.67b/IDA-1.5 for ); Wed, 29 Nov 1995 11:36:33 +0100 Message-Id: <199511291036.AA17411@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817680631.001 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: one question Date: Wed, 29 Nov 1995 11:36:38 +0100 To: Steve and Kevin >For much the same reasons that I don't like "relativistic mass", >I don't like the notion of imparting momentum to a non-moving >object. Clearly it has lead to some incorrect physical >thinking. If something can't be put into uniform linear motion >relative to something else, then it can't "absorb momentum" >relative to that thing. While for relativistic mass there is just a different word for the same thing, there is in this case no other word. The word that here is invented is "imparted momentum" which should replaced by the word "energy". Timothy ------------------------------------------------------------------------------- Subject: Physics store >Others have given you the address of the Acme Physics Warehouse. >The stuff you want is probably in the "Cartoon Physics" section; >the "Real Physics" section just has stuff like point masses, >frictionless surface coatings, and ideal gases. I'm not sure, that unobtanium with its negative mass seemed to come from the same store. But if you are right, then that Wile guy has lied to me and probably is on the run with my down payment. :( >You can do antigravity in several ways. One is to keep a >suspended creature permanently in ignorance of its altitude with >special blinders; as you know, creatures won't fall until they >know they are above a canyon. Another is to surprise a creature, >causing it to levitate above the ground, then keep it in that >state; you can get boxes of carefully bred mice that are easily >surprised. Someone in love will float above the ground, and can >be tugged around simply by the scent of the loved one, implying >minimal inertia; tailored "love drugs" can be used to induce this >state. All these examples seem to have some mental control mechanism. That probably means that I have to do a lot of yoga lessons first. Timothy ------------------------------------------------------------------------------- To: Steve >There is one important constraint in this situation: photons >_always_ have equal momentum and energy; hence a photon >reflecting off a moving object must impart equal amounts of >momentum and energy to it. Yes, I was aware of that: U = p c >A photon has less energy when seen from the frame of a >fast-moving object moving in the same direction as the photon, so >in the object frame the photon imparts less momentum to the >object. Seen from the observer's frame, the photon loses more >momentum to a receding fast-moving object than a slow-moving one. Indeed, that would make it right in all frames. >Remember that reflecting objects moving opposite to the direction >of the incident photons actually impart energy and momentum to >the photons; in the object frame the photon has more energy and >momentum. Yes, because the moving observer would see a higher energy than an observer at rest. > > After all this, can we conclude a charged battery is heavier than an > > uncharged battery? > >Yes, this is also true. Hot objects are heavier than cold ones >(although not by an amount we have equipment to measure). A >mirrored box full of photons is heavier than the empty box. And it doesn't matter if they all move parallel and in the same direction all the time, right? Here is another one: If two particles feel the gravity of each other, then they are heavier together than if they are separate because of the extra gravitational energy. > > Yes, in fact is does not take any energy to keep floating a few metres above > > Earth's surface. > >Well, it depends on how you make the object float. No, if you for example use a helicopter, it does not take energy to stay at that height but it does take energy to move all the air. A true anti-gravity source would only have to build up a anti-gravity field once and does not use energy to stay at a certain heigh. If you use two magnets or two charged plates (both positive or negative) they also would not use any energy after you levitated. Timothy From popserver Thu Nov 30 08:27:17 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6897" "Thu" "30" "November" "1995" "09:21:50" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "172" "Engineering newsletter" "^From:" nil nil "11" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA25659; Thu, 30 Nov 95 00:19:01 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24811 (5.67b/IDA-1.5 for ); Thu, 30 Nov 1995 09:21:43 +0100 Message-Id: <199511300821.AA24811@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817719805.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering newsletter Date: Thu, 30 Nov 1995 09:21:50 +0100 Bb accident, I mailed this letter only to Kelly yesterday. So here is it for the rest of you. Subject : (Star)Wars > > One very consistent problem in LIT over the last year has been > > a very limited interest in the engineering realities of a > > situation, and to much fondness for endless equation wars. > >These are not equation wars; as this message shows, you don't >always have to use math to talk about physics. We are talking >about very real physics concepts, and I'm afraid you are the one >who has a few important ones wrong. > >Before we can do the detailed engineering for a starship, we need >to understand what physical constraints it will be under. Even >the best engineering cannot violate the laws of physics. If we >are engaged in "equation wars", it is because we are trying to >figure out the limits of what is possible before we do detailed >design work based on faulty assumptions. This is the most >fundamental interest in engineering realities you could want. Steve, I've nothing to add, you're completely right. Timothy =============================================================================== ReplyTo : Kelly >From : Timothy Subject : Prelaunching >>> This method of prelaunching fuel packets will cost the >>> same amount of energy that is needed if you take those >>> same packets with you from the start. > >True, but since the ship doesn't have to supply the energy, it saves an >incredable amount of fuel. The ship does not have to supply the energy! It will leave fully fueled. It is still accelerated by some kind of photon beam. >To put it bluntly no fusion powered ship could >carry enough fuel, to accelerate itself and its fuel up to high reletivistic >speeds. Estimates are that a ship would need a 1,000,000 to 1 fuel to ship >mass ratio to get up to $10 of light speed. But if the ship doesn't have to >carry its fuel, a 200 to 1 ratio could get you most of the way to light speed >(or was that 1/3rd light speed. Been a while since GES ran the numbers off >for me.) Huh, if it doesn't carry its fuel, how do you calculate a ratio? !! Please be specific if you mean FUEL or REACTION MASS !! >>> The problem is that there are no accurate numbers of >>> the density of interstellar debris. So any number is almost >>> a guess. > >Thats been a constand problem for us. How do you design a ship to travel >through something you know next to nothing about? It would be best if we could find a solution without using the interstellar particles, but at the same time we should keep in mind that we have to protect us against it. This may sound a bit contradictory but a general solution would be best. =========================================================================== ReplyTo : Kelly >From : Timothy Subject : Plasma mirror >>> Replenishing the "mirror" will probably take lots of ions >>> or in other words mass that has to be taken with us. > >Agreed, but it don't have a handel on the amount of mass. Why doesn't it have to do with the amount of mass? Ions are particles too. They may have small masses, but if you have enough of them you could build a complete dragon-fly sail. >>> Also using such a light (non heavy) sail will mean that >>> the "mirror" is accelerated a lot and lot of energy is lost >>> due to the Doppler effect. > >Given that the mirror is the surface of a plasma, and said plasma is being >continuously being replenished. I'm not sure the reflective "surface" is >actually moving? Althou obviously the particals in the plasma are moving >(and accelerating) rapidly. Are the micro waves reflecting off the >particals? Or off the area where the plasma is ionized enough to reflect >them? Probably all the way in between. But that is not important here, because a reflection means transfer of momentum, and with it energy. Since the plasma will be accelerated a lot, it will retrieve a lot of energy. >>> Also I have doubts how well the "mirror" reflects, ionized >>> particles attract or repell each other so, it won't take long >>> befor the "mirror" has destroyed itself. > >The ions in a plasma of the same material wil repell each other. You might >be able to do some magnetic tricks to hold it, but it probably wouldn't be >worth the trouble. > >[ Hum --- I wounder if you could wiggle the exausting plasma to for a laser >to get back some of the energy? ] Don't talk about plasma as if it where some easy to control stuff. The movement of the plasma itself would create magnetic fields. It's like boiling water but much worse. >As to reflectivity. That would depend on the nature of the plasma and a lot >of other variables. This is probably not a question we could easily figure >out for ourselves. >>> Shock wave? I don't understand, please explain again. > >You have a mass of plasma being hit with E18 of energy. It will be HOT, and >highly ionized. It will be explosivly expanding. The light pressure of the >beam (or the feed mass) will probably keep it from flowing straight up the >beam. But it will be moving rapidly to the sides and forward or the ship. > We should be able to tap this for thrust. My guess is that this shock wave will move mostly forward instead of backward. You seem to want to do the same thing Kevin did: Make a easy thing complicated and so loose complete control over what you are doing. Whatever method you can think of, it will take just as much energy that the dragon-fly-sail will use. ============================================================================== ReplyTo : Kelly >From : Timothy Subject : Floating <> flying >>> Yes, in fact is does not take any energy to keep floating a >>> few metres above Earth's surface. > >(???????!!!!!!) SAY WHAT!! Unless we're on differnt planets you have to >generate or disapate as much energy as to generate 9.8 m/s^2 of acceleration. No, I wasn't in the Acme physics store... I refer to the answer I wrote to Steve about this same thing and add some formulas: F = m a U = F s = m a s P = U / t Where F=force, U=energy, m=mass, a=acceleration, s=distance_moved, t=time_needed In 4.3 seconds I will evenly pull a mass of 1.3 kg 2.6 metres up in Earth's g=9.8 m/s^2 That will take a force F=1.3*9.8=12.74 Newton and an amount of energy U=12.74*2.6=33.124 Joule and will take a power of P=33.124/4.3=7.703 Watt So if we are talking about weightlifting, there are several phases. First the weightlifter has to get the weight from the ground to up his head. That is where the real energy is needed, since there is a distance of movement involved. After he/she has lifted the weight and keeps it above his/her head the real work is done. All that the weightlifter has to do is keep his muscles in place. But that energy is not added to the weights. Often it is more difficult to get the weight up than to keep it there, that is just because of this reason. From popserver Fri Dec 1 21:18:52 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["671" "Fri" "1" "December" "1995" "12:23:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "16" "Too bad" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA12288; Fri, 1 Dec 95 03:21:07 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA22517 (5.67b/IDA-1.5 for ); Fri, 1 Dec 1995 12:23:47 +0100 Message-Id: <199512011123.AA22517@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 817852487.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Too bad Date: Fri, 01 Dec 1995 12:23:58 +0100 Here some great idea, but not really... Space is "filled" with the so called background radiation, right? What would happen to an object that has a perfect mirror on one side? Right, the mirror would reflect the background radiation. So this extra momentum at that one side would make the object move in the opposite direction. Wow, this makes movement easy, but not really... Since the background radiation is so small you would need enormous mirrors of light weight. Probably solar radiation over 10 ly. would work even better. So, too bad, if only the background radiation was about 500 Kelvin, but probably that would cook us all... OK, next time better. Timothy From popserver Fri Dec 1 21:18:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1826" "Fri" "1" "December" "1995" "07:24:10" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "45" "Re: one question" "^From:" nil nil "12" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA14918; Fri, 1 Dec 95 05:21:56 PST Received: by maroon.tc.umn.edu; Fri, 1 Dec 95 07:24:11 -0600 In-Reply-To: <199511282300.PAA21239@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817852487.001 From: Kevin C Houston To: Steve VanDevender Cc: Steve VanDevender , rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: one question Date: Fri, 1 Dec 1995 07:24:10 -0600 (CST) On Tue, 28 Nov 1995, Steve VanDevender wrote: > What I was really objecting to in your parasail design was not > the idea that you had cancelling momenta, but that you thought > that creating sideways momentum meant a decrease in forward > momentum. For example, a device like this: > > > E/c --v :::: p = [ 0 E/(2*c) ] > |----------------------------------:::/| > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::/ | > |######~~~~~L~A~S~E~R~~~~~~~~~~~~~~:/ | beam splitter > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~:\ | > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::\ | > |----------------------------------:::\| > :::: p = [ 0 -E/(2*c) ] > > # = laser ~ = laser light -- = wires > > also won't move. The beam splitter "absorbs momentum" just like > the black absorbing plate did, even though it splits the beam > into two beams traveling in the +y and -y directions. This setup > also has the advantage of not requiring an unobtainium heat sink, > as long as you get a Perfect Mirror (tm) from Acme Physics > Warehouse. So you're saying that the beam splitter above would move at the same speed as a absorbtion plate of the same mass? > > > The wires are indeed under tension, because there is a force > > > between the laser and the plate. This tension was created in the > > > first instant the laser was turned on, and a small amount of its > > > energy went into stretching the wires before it was all spent on > > > heating the plate. > > I've always been taught to view atomic bonds as tiny springs which obey hookes law F=kx where k is some constant. this is the force that balances the force of the laser / absorber plate. Is this view correct? Doesn't a spring provide a constant force as long as it's stretched from it's initial position? From popserver Fri Dec 1 22:10:45 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2934" "Fri" "1" "December" "1995" "14:06:26" "-0800" "Steve VanDevender" "stevev@efn.org" nil "59" "Re: one question" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA14297; Fri, 1 Dec 95 14:02:40 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id OAA02463; Fri, 1 Dec 1995 14:06:26 -0800 Message-Id: <199512012206.OAA02463@tzadkiel.efn.org> In-Reply-To: References: <199511282300.PAA21239@tzadkiel.efn.org> X-UIDL: 817855596.001 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: one question Date: Fri, 1 Dec 1995 14:06:26 -0800 Kevin C. Houston writes: > > For example, a device like this: > > > > > > E/c --v :::: p = [ 0 E/(2*c) ] > > |----------------------------------:::/| > > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::/ | > > |######~~~~~L~A~S~E~R~~~~~~~~~~~~~~:/ | beam splitter > > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~:\ | > > |######~~~~~~~~~~~~~~~~~~~~~~~~~~~~::\ | > > |----------------------------------:::\| > > :::: p = [ 0 -E/(2*c) ] > > > > # = laser ~ = laser light -- = wires > > > > also won't move. The beam splitter "absorbs momentum" just like > > the black absorbing plate did, even though it splits the beam > > into two beams traveling in the +y and -y directions. This setup > > also has the advantage of not requiring an unobtainium heat sink, > > as long as you get a Perfect Mirror (tm) from Acme Physics > > Warehouse. > > So you're saying that the beam splitter above would move at the same > speed as a absorbtion plate of the same mass? It would get momentum p from a beam with momentum p just like the perfect absorber would. However, over time it would end up at a higher speed than the absorber because it does not increase in mass over time like the absorber does. The absorber develops momenergy [ m+p p 0 0 ] after absorbing photons with momenergy [ p p 0 0 ], so its mass increases to sqrt(m^2 + 2 * p * m) (if p << m, this approximates to m + p), while the beam splitter develops momenergy [ sqrt(m^2+p^2) p 0 0 ] from splitting the same beam because its mass remains a constant m. Hence the velocity of the absorber after absorbing light with momentum p is p / sqrt(m^2 + 2*p*m), while the velocity of the beam splitter is p / sqrt(m^2 + p^2). > > > > The wires are indeed under tension, because there is a force > > > > between the laser and the plate. This tension was created in the > > > > first instant the laser was turned on, and a small amount of its > > > > energy went into stretching the wires before it was all spent on > > > > heating the plate. > I've always been taught to view atomic bonds as tiny springs which obey > hookes law F=kx where k is some constant. this is the force that > balances the force of the laser / absorber plate. Is this view correct? > Doesn't a spring provide a constant force as long as it's stretched from > it's initial position? Note that F = k * x means that the force varies linearly with displacement, so increasing displacement means increasing force. A spring provides constant force as long as it remains stretched the same amount. This may be what you meant above, but you don't seem to make the distinction that the spring force varies with displacement. F = k * x is approximately correct for "ideal" springs and small displacements and may be valid for normal materials under small amounts of tension or compression; I don't know for sure. From popserver Sun Dec 3 01:21:14 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["4714" "Sat" "2" "December" "1995" "20:07:37" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951202200736_42256412@emout05.mail.aol.com>" "119" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "12" nil nil nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA15503; Sat, 2 Dec 95 17:05:09 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id UAA15378; Sat, 2 Dec 1995 20:07:37 -0500 Message-Id: <951202200736_42256412@emout05.mail.aol.com> X-UIDL: 817953394.014 From: KellySt@aol.com To: stevev@efn.org Cc: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Sat, 2 Dec 1995 20:07:37 -0500 to: stevev@efn.org > > If a static structure had to dissipate energy continuously to > > remain standing, where would such energy come from? Why doesn't > > your house fall down? Where are the batteries? > > The energy is coming from the gravitational attraction of the earth. It is > disapated as heat in the structure of the house. In a structure under heavy > loads (too heavy) you can feel the heat in the structure. Steve>> Really? So when does the earth run out of gravity? When space gets tired of curving? ;) Steve>> I think you've spent too much time in the Cartoon Steve>> Physics section of Acme Physics Warehouse. Steve>> Tell me about one of these structures that I can go Steve>> visit, put my hand on, and feel the heat. Over stressed cable stayed structures are about the only ones I've delt with that I could feel the differnce in. Others are too low to feel, but insterments can detect it. ======================================================== : stevev@efn.org KellySt@aol.com writes: > >> Besides not treating momentum as a vector quantity, people are > >> making the mistake of thinking that lateral loading of the sail > >> assembly is a magical sink for momentum or energy. The error is > >> in thinking that stress on a static structure absorbs energy or > >> momentum continuously over time. If the sail does not move > >> relative to the ship, then it cannot absorb or dissipate momentum > >> separately from the ship. It cannot absorb momentum if it does > >> not move, because momentum means motion. ---- > > (??!) > Thats like the old argument that if a tractor is pushing against a wall its > doing no work, since the wall isn't accelerated. The sail is getting a > thrust that is perpendicular to the surface of reflection. If you want to > describe the portion of the thrust that isn't accelerating the ship as > invalid, enjoy. S >> The tractor is dissipating energy because it contains S >> moving parts in its engine and drive train that keep S >> moving even though the tractor chassis and the wall S >> are not. Now whos trying to talk their way out of a corner. Try a direct drive electric tractor. Nothing turns unless the vehical moves. So where does the power go if nothing moves? -- S >> Lean a board against the wall. Does it dissipate energy S >> because it can't move the wall? Lean a heavy iron bar S >> against the wall. Does it dissipate more energy than S >> the board? They are under a constant 1 g thrust. They are under the load resisting that takes. Where do you think that power goes? S >> Are the bricks at the bottom of the wall permanently S >> warmer than the bricks at the top because they are under S >> compression? Yes. S >> --- You can't claim that gravity is continuously pumping S >> energy into the objects; you can't gain or lose energy if S >> you don't move up or down in a gravity field. If non-moving structures are not continuously being subjected to a force, what keeps them under continuous presure? Something is crushing their molecular structures enough to put them under a load. If that presure was removed, or droped, they would expand. In the same way the structure in the sail bracing is under continuous stress. S >> My intention was to prove that Kevin's parasail design S >> couldn't absorb photons without absorbing their S >> momentum. But you can divert the thrust vectors to a non-forward direction. in a reflection. Its not going to buy you anything is you later absorb the photons anyway, but it is a usefull trick to move the beam around without geting shoved by it. (Frankly with all the bouncing, have defined equations getting tossed around I'm not sure if that was Kevins point anymore.) s >> You seem to have a real misunderstanding of the s >> difference between work and potential. When you put a s >> structure under tension or compression, you do change s >> its energy, ONCE, when you slightly pull apart or scrunch s >> together Actually, I'm probably not being as clear as I might be. However, the differnce if fairly accademic as far as the ships concerned. > One very consistent problem in LIT over the last year has been > a very limited interest in the engineering realities of a > situation, and to much fondness for endless equation wars. s >> These are not equation wars; as this message shows, you s >> don't always have to use math to talk about physics. But in the Equation wars, no one was using anything but equations (usually not well explained or defined). This not only caused confusion to everyone else, it frequently tripped up the person making the statment Kelly From popserver Sun Dec 3 01:21:17 GMT 1995 X-VM-v5-Data: ([nil nil nil t t nil nil nil nil] ["412" "Sat" "2" "December" "1995" "20:07:48" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951202200747_42256550@emout04.mail.aol.com>" "17" "Re: one question" "^From:" nil nil "12" nil nil nil nil] nil) Received: from emout04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA15518; Sat, 2 Dec 95 17:05:38 PST Received: by emout04.mail.aol.com (8.6.12/8.6.12) id UAA13841; Sat, 2 Dec 1995 20:07:48 -0500 Message-Id: <951202200747_42256550@emout04.mail.aol.com> X-UIDL: 817953394.015 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: one question Date: Sat, 2 Dec 1995 20:07:48 -0500 >> > > Yes, in fact is does not take any energy to keep floating a few metres above >> > > Earth's surface. > >> >Well, it depends on how you make the object float. >> No, if you for example use a helicopter, it does not take energy to stay at >> that height but it does take energy to move all the air. >> Timothy Hold your arm out to you side. Tell me it takes no effort (energy) to hold it there. Kelly From popserver Sun Dec 3 01:21:18 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7156" "Sat" "2" "December" "1995" "20:08:04" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "171" "Re: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from emout04.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA15541; Sat, 2 Dec 95 17:06:18 PST Received: by emout04.mail.aol.com (8.6.12/8.6.12) id UAA13942; Sat, 2 Dec 1995 20:08:04 -0500 Message-Id: <951202200804_42256799@emout04.mail.aol.com> X-UIDL: 817953394.016 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Sat, 2 Dec 1995 20:08:04 -0500 >From : Timothy Subject : Prelaunching >>> This method of prelaunching fuel packets will cost the >>> same amount of energy that is needed if you take those >>> same packets with you from the start. > >True, but since the ship doesn't have to supply the energy, it saves an >incredable amount of fuel. TV > The ship does not have to supply the energy! It will leave TV > fully fueled. It is still accelerated by some kind of TV > photon beam. No, Kevins starship design is propelled by a photon (maser) beam. My origional Explorer design is propelled by fusion powered mass drivers. I call it an externally feed system since the fuel is thrown out ahead of the ship by a launcher in Sol. (See my Explorer starship design page on the LIT site.) Thats probably the central thing confusing you. Unless your confusing the Explorer ship with the plasma mirror design I came up with more recently. >To put it bluntly no fusion powered ship could >carry enough fuel, to accelerate itself and its fuel up to high reletivistic >speeds. Estimates are that a ship would need a 1,000,000 to 1 fuel to ship >mass ratio to get up to 10% of light speed. But if the ship doesn't have to >carry its fuel, a 200 to 1 ratio could get you most of the way to light speed >(or was that 1/3rd light speed. Been a while since GES ran the numbers off >for me.) TV > Huh, if it doesn't carry its fuel, how do you calculate a ratio? Figure out how much fuel it would take to run the reactors & engines enough to accelerate the ship (but not its fuel) up to speed. TV > !! Please be specific if you mean FUEL or REACTION MASS !! I was being specific. I ment fuel. (Thou I suppose you could save some bucks by adding in extra reaction mass to the launched shipments.) >>> The problem is that there are no accurate numbers of >>> the density of interstellar debris. So any number is almost >>> a guess. > >Thats been a constand problem for us. How do you design a ship to travel >through something you know next to nothing about? TV > It would be best if we could find a solution without using the interstellar TV > particles, but at the same time we should keep in mind TV > that we have to protect us against it. This may sound a TV > bit contradictory but a general solution would be best. How about working out a high and low range based on the most and least mass expected out there? =========================================================================== ReplyTo : Kelly >From : Timothy Subject : Plasma mirror >>> Replenishing the "mirror" will probably take lots of ions >>> or in other words mass that has to be taken with us. > >Agreed, but I don't have a handel on the amount of mass. TV > Why doesn't it have to do with the amount of mass? Don't understand you question. I was assuming it would depend on the mass, but I didn't know how much mass that would be. TV > Ions are particles too. They may have small masses, TV > but if you have enough of them you could build a TV > complete dragon-fly sail. I don't know which system would be lighter, but of course we couldn't build the dragon-fly system, so thats kind of a mute point. >>> Also using such a light (non heavy) sail will mean that >>> the "mirror" is accelerated a lot and lot of energy is lost >>> due to the Doppler effect. > >Given that the mirror is the surface of a plasma, and said plasma is being >continuously being replenished. I'm not sure the reflective "surface" is >actually moving? Althou obviously the particals in the plasma are moving >(and accelerating) rapidly. Are the micro waves reflecting off the >particals? Or off the area where the plasma is ionized enough to reflect >them? TV > Probably all the way in between. But that is not important TV > here, because a reflection means transfer of momentum, TV > and with it energy. Since the plasma will be accelerated TV > a lot, it will retrieve a lot of energy. Do you mean absorb a lot of energy? That is a problem with a drop mirrow or plasma mirror idea. But as long as you can do it and get thrust to decelerate the ship (the big problem in al this), it might work well enough to get us somewhere. (Assuming the whole thing doesn't melt the ship!) >>> Also I have doubts how well the "mirror" reflects, ionized >>> particles attract or repell each other so, it won't take long >>> befor the "mirror" has destroyed itself. > >The ions in a plasma of the same material wil repell each other. You might >be able to do some magnetic tricks to hold it, but it probably wouldn't be >worth the trouble. > >[ Hum --- I wounder if you could wiggle the exausting plasma to for a laser >to get back some of the energy? ] TV > Don't talk about plasma as if it where some easy to TV > control stuff. The movement of the plasma itself would TV > create magnetic fields. It's like boiling water but much TV > worse. I didn't say it was going to be easy. (Thou compared with the sail, the power generator, and transmitters; It will be a snap!) I just said it might be worth doing. I mean the plasma will have a LOT of energy in it. It might be worth tapping some off. >As to reflectivity. That would depend on the nature of the plasma and a lot >of other variables. This is probably not a question we could easily figure >out for ourselves. >>> Shock wave? I don't understand, please explain again. > >You have a mass of plasma being hit with E18 of energy. It will be HOT, and >highly ionized. It will be explosivly expanding. The light pressure of the >beam (or the feed mass) will probably keep it from flowing straight up the >beam. But it will be moving rapidly to the sides and forward or the ship. > We should be able to tap this for thrust. TV > My guess is that this shock wave will move mostly TV > forward instead of backward. If by forward, you mean toward Tau C. I agree. But like you said, plasmas get messy. One this hot will be blasting outward violently! We might be able to use the lateral plasma stream to push the ship beamwards. (Every little bit helps.) TV > You seem to want to do the same thing Kevin did: Make a TV > easy thing complicated and so loose complete control TV > over what you are doing. Whatever method you can think TV > of, it will take just as much energy that the TV > dragon-fly-sail will use. On the contrary. I'm trying to take a very complicated system and make it simpler. Notice I don't have the massive microwave to electric power converters of Kevin's origional drive system. Nor do I have the ultra exotic A.I. controled active structure of Forwards drop reflector sail. Forwards design would have had to steer itself, while steering the reflected beam back to the main ship, while tracking the main ship over interstellar distences. This is not easy, and it is REALLY pushing the envelope of probable 2050 technologies! On the other hand my plasma mirror idea would all take place in the area of the ship, and be directly controlable by the ship. Assuming it wasn't mass or energy prohibative, it would clearly be the prefered system. (Assuming it would work of course.) Kelly From popserver Sun Dec 3 02:57:05 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9996" "Sat" "2" "December" "1995" "18:56:38" "-0800" "Steve VanDevender" "stevev@efn.org" nil "211" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA19543; Sat, 2 Dec 95 18:52:32 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id SAA02132; Sat, 2 Dec 1995 18:56:38 -0800 Message-Id: <199512030256.SAA02132@tzadkiel.efn.org> In-Reply-To: <951202200736_42256412@emout05.mail.aol.com> References: <951202200736_42256412@emout05.mail.aol.com> X-UIDL: 817959168.000 From: Steve VanDevender To: KellySt@aol.com Cc: stevev@efn.org, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Sat, 2 Dec 1995 18:56:38 -0800 KellySt@aol.com writes: > to: stevev@efn.org > > > If a static structure had to dissipate energy continuously to > > > remain standing, where would such energy come from? Why doesn't > > > your house fall down? Where are the batteries? > > > > The energy is coming from the gravitational attraction of > > the earth. It is disapated as heat in the structure of the > > house. In a structure under heavy loads (too heavy) you > > can feel the heat in the structure. > > Steve>> Really? So when does the earth run out of gravity? > > When space gets tired of curving? ;) So what you are saying is that any gravitational source is a supply of infinite energy. All one need do is hang a weight from a wire or stack up a bunch of bricks, attach a thermocouple to the now warmer structure, and get free electricity, forever. This is such an amazingly simple principle that I am surprised such a method pf power generation has not been tapped already. Who needs sunlight to evaporate water to fall as rain to flow through rivers to run hydroelectric generators, when one could use a farm of gravitationally stretched or compressed objects and a heat exchanger to run a boiler to make steam to run the generators instead? The curvature of space also carries energy, but a finite amount. Objects in a gravitational field can't dissipate heat forever; the energy has to come from somewhere, and there is no such thing as an infinite inexhaustible supply of energy in the universe. > Steve>> I think you've spent too much time in the Cartoon > Steve>> Physics section of Acme Physics Warehouse. > > Steve>> Tell me about one of these structures that I can go > Steve>> visit, put my hand on, and feel the heat. > > Over stressed cable stayed structures are about the only ones I've delt with > that I could feel the differnce in. Others are too low to feel, but > insterments can detect it. Are these structures under true static stress? Is the heat coming from an overstressed, gradually elongating cable (in which case work is being done on the cable material), or can you set up such a structure and get heat from it forever without degeneration of the structure? If so, how do you explain getting more heat from the structure than you put energy into it when you built it? If such a structure could persist indefinitely, how do you explain where the energy came from when the structure has been around long enough that the total dissipated energy exceeds the energy equivalent of the mass of the structure and the gravitational source? > KellySt@aol.com writes: > > >> Besides not treating momentum as a vector quantity, people are > > >> making the mistake of thinking that lateral loading of the sail > > >> assembly is a magical sink for momentum or energy. The error is > > >> in thinking that stress on a static structure absorbs energy or > > >> momentum continuously over time. If the sail does not move > > >> relative to the ship, then it cannot absorb or dissipate momentum > > >> separately from the ship. It cannot absorb momentum if it does > > >> not move, because momentum means motion. ---- > > > > (??!) > > Thats like the old argument that if a tractor is pushing against a wall > its > > doing no work, since the wall isn't accelerated. The sail is getting a > > thrust that is perpendicular to the surface of reflection. If you want to > > describe the portion of the thrust that isn't accelerating the ship as > > invalid, enjoy. > > S >> The tractor is dissipating energy because it contains > S >> moving parts in its engine and drive train that keep > S >> moving even though the tractor chassis and the wall > S >> are not. > > Now whos trying to talk their way out of a corner. Try a > direct drive electric tractor. Nothing turns unless the > vehical moves. So where does the power go if nothing moves? If an electric motor is prevented from turning then the energy that is not producing motion heats the motor windings; if the motor does not turn then the windings are an electrical short circuit. An ideal electric motor draws no power if it does no work. As you should know as a student of engineering, ideal motors are as common as unbending beams. Any real motor has resistive and mechanical losses that will cause it to draw power even if it does no work. I can keep this up for a long time, because I know what I'm talking about. You are making claims that would get you a lot of stern looks from your physics professor, if not outright laughter. > S >> Lean a board against the wall. Does it dissipate energy > S >> because it can't move the wall? Lean a heavy iron bar > S >> against the wall. Does it dissipate more energy than > S >> the board? > > They are under a constant 1 g thrust. They are under the load > resisting that takes. Where do you think that power goes? There is no power dissipation, because there is no motion. Power isn't going anywhere. Power is work over time. Work is force times distance. A force that is prevented from producing motion produces no work; no work over any amount of time is no power. You have equated work (or energy) with force, a mistake that should have been corrected in your first class that covered Newtonian physics. > S >> Are the bricks at the bottom of the wall permanently > S >> warmer than the bricks at the top because they are under > S >> compression? > > Yes. You need to have a long, long talk with a physics professor. > S >> --- You can't claim that gravity is continuously pumping > S >> energy into the objects; you can't gain or lose energy if > S >> you don't move up or down in a gravity field. > > If non-moving structures are not continuously being subjected to a force, > what keeps them under continuous presure? Something is crushing their > molecular structures enough to put them under a load. If that presure was > removed, or droped, they would expand. In the same way the structure in the > sail bracing is under continuous stress. That stress requires extension in space. It is true that moving up and down in a gravity field changes the energy of the object. But if no motion occurs, there is no change in energy. The compression of the structure occurred once and added a finite amount of energy to it. There is no continuous dissipation of energy as you seem to think; the bricks at the bottom of the wall got warmer just after the other bricks were stacked on top of them, but do not stay warmer forever, because no more work is done on them. No motion through the gravity field means no work; no work is no energy. > S >> My intention was to prove that Kevin's parasail design > S >> couldn't absorb photons without absorbing their > S >> momentum. > > But you can divert the thrust vectors to a non-forward direction. in a > reflection. Its not going to buy you anything is you later absorb the > photons anyway, but it is a usefull trick to move the beam around without > geting shoved by it. (Frankly with all the bouncing, have defined equations > getting tossed around I'm not sure if that was Kevins point anymore.) You can reflect different parts of the beam in different directions to produce sideways components of momentum that cancel over the entire structure. You cannot take forward momentum and turn it into sideways momentum without giving the forward momentum completely to something else. When I say that momentum is a vector quantity and is conserved as a vector quantity, what I mean is that if you have a quantity of momentum, its direction is as important as its magnitude, and although you can divide the momentum up however you like, even split zero components into complementary non-zero components aimed in opposite directions, the sum of all the momenta of all the things you divide it up among sums to momentum in the same direction with the same magnitude. The ship gets all of the forward momentum of each photon it absorbs, no matter how the photon was reflected or redirected before the ship finally absorbed it. There is no other way to satisfy conservation of momentum. > s >> You seem to have a real misunderstanding of the > s >> difference between work and potential. When you put a > s >> structure under tension or compression, you do change > s >> its energy, ONCE, when you slightly pull apart or scrunch > s >> together > > Actually, I'm probably not being as clear as I might be. However, the > differnce if fairly accademic as far as the ships concerned. Frankly, your understanding of physics would get you marked as a raving loon. > > One very consistent problem in LIT over the last year has been > > a very limited interest in the engineering realities of a > > situation, and to much fondness for endless equation wars. > > s >> These are not equation wars; as this message shows, you > s >> don't always have to use math to talk about physics. > > But in the Equation wars, no one was using anything but equations (usually > not well explained or defined). This not only caused confusion to everyone > else, it frequently tripped up the person making the statment How much math have I used to explain conservation of energy and momentum here? I think I have a clear and accurate understanding of those concepts, which does not lead me to the contradictory conclusions you are coming up with. Your claims quite clearly imply that you can get indefinite amounts of heat energy from an unmoving structure in a gravitational field, because you say a structure in a gravitational field is warmer and stays warmer than an equivalent structure not in a gravitational field. You cannot claim to be playing by the same rules of physics that the rest of us are trying to play by. Your knowledge of physics has flaws and gaps that I have already spent too much time trying to correct and fill. From popserver Sun Dec 3 04:16:42 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1686" "Sat" "2" "December" "1995" "19:19:08" "-0800" "Steve VanDevender" "stevev@efn.org" nil "41" "Re: one question" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA20322; Sat, 2 Dec 95 19:14:58 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id TAA02187; Sat, 2 Dec 1995 19:19:08 -0800 Message-Id: <199512030319.TAA02187@tzadkiel.efn.org> In-Reply-To: <951202200747_42256550@emout04.mail.aol.com> References: <951202200747_42256550@emout04.mail.aol.com> X-UIDL: 817963945.000 From: Steve VanDevender To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: one question Date: Sat, 2 Dec 1995 19:19:08 -0800 KellySt@aol.com writes: > >> > > Yes, in fact is does not take any energy to keep > >> > > floating a few metres above Earth's surface. > > > >> >Well, it depends on how you make the object float. > > >> No, if you for example use a helicopter, it does not take > >> energy to stay at that height but it does take energy to > >> move all the air. > > >> Timothy > > Hold your arm out to you side. Tell me it takes no effort (energy) to hold > it there. Your muscles are not static structures, as I have pointed out before. They produce force with protein fibers that must continually dissipate energy by moving molecules around to maintain constant tension. This constant chemical activity is what you feel as effort when you hold out your arm. Now nail a board at a right angle to a vertical post. How much energy does it take to hold it there? None. How much energy did it take to put it there? Some to lift the board and pound the nails. The motions required to do those actions performed work; they involved application of force over a distance. Some of this work heated the nails and the board; once you are done pounding no more energy is put into the nails or the board, and they cool. Once they cool to ambient temperature no more energy goes into or out of the board and the nails. Gravity cannot change the energy of the board because the board does not move through the gravitational field. That it takes effort for your body to produce a constant force does not mean that all forces result from constant effort (dissipation of energy). It means that your body is not an ideal machine. A force that produces no motion dissipates no energy. From popserver Sun Dec 3 10:37:08 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4895" "Sun" "3" "December" "1995" "00:22:14" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "114" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "12" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA26674; Sat, 2 Dec 95 22:19:47 PST Received: by maroon.tc.umn.edu; Sun, 3 Dec 95 00:22:15 -0600 In-Reply-To: <199512030256.SAA02132@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 817986764.003 From: Kevin C Houston To: Steve VanDevender Cc: KellySt@aol.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Sun, 3 Dec 1995 00:22:14 -0600 (CST) On Sat, 2 Dec 1995, Steve VanDevender wrote: > > S >> My intention was to prove that Kevin's parasail design > > S >> couldn't absorb photons without absorbing their > > S >> momentum. i now accept this point as proven. > You can reflect different parts of the beam in different > directions to produce sideways components of momentum that cancel > over the entire structure. You cannot take forward momentum and > turn it into sideways momentum without giving the forward > momentum completely to something else. When I say that momentum Okay, let's think about that for a moment. Is it possible to absorb the photons into the Reaction Mass (RM), giving all of the energy _and_ momentum to the exhaust stream. since the exhaust stream consists of (ideally) the recieved photons and extra mass, would this slow the system. Half formed idea follows: (modifications/analysis welcomed) __________ |RM inlet ship's core /"/ Power from Sol ______________/"/________ ~~~~~~~~~~~~~~~~~~~~~~============"="="="="="="="="="" exhaust and power ~~~~~~~~~~~~~~~~~~~~~~============="="="="="="="="="=" ~~~~~~~~~~~~~~~~~~~~~~============"="="="="="="="="="" ______________ _________ \"\ \"\ |RM inlet ~ Photons going one way = photons going both directions (canceling? hope not) " Reaction Mass Of course this assumes we can aim a maser straight up the butt of the ship over light years, which of course we cant. But, numerous reflections could collect the energy over square kilometers, and focus it in the required manner, producing the same net result. If your objection is to this paragraph, then hold your horses, because I'm dubious about this part myself. remember, I just thought this up about 20 miuntes ago (as I'm writing this) so there may be a few bugs my question is this: does the ship slow down? I think it should. (but I've been wrong before) before the interaction, the ship and the RM were traveling to the right with some speed V. after the interaction, the RM is traveling at a greatly increased speed to the right, and the photon beam is traveling to the left. (complete reflection -- don't ask me how, just assume it for the moment.) Now absorb the photon beam and convert it to electricity. (the ship should act as though the photons came from Tau Ceti, slowing even more.) -- again, we either need a magical one-way absorber at the ~/= interface (~ photons enter from the left, = photons are absorbed from the right), or a complicated series of reflectors. or we have to abandon the photons capture and just let all that lovely energy zing back to earth. the electricity (if we can capture it) can then be used to power a lineac, acellerating the plasma stream even more. which definitly would slow the ship I think this is what Kelly was trying to get at with his plasma mirror, but this puts the mirror inside the ship. I realize that I'm talking about some very very complicated twists and turns, but just answer the following question. is this system physically possible? does it preserve momenergy, and does the ship slow down. we can worry about the merely difficult engineering tasks later. > is a vector quantity and is conserved as a vector quantity, what > I mean is that if you have a quantity of momentum, its direction > is as important as its magnitude, and although you can divide the > momentum up however you like, even split zero components into > complementary non-zero components aimed in opposite directions, > the sum of all the momenta of all the things you divide it up > among sums to momentum in the same direction with the same > magnitude. > here's how I see it breaking down, 1 photons reflecting off RM: Momenergy (very dangerous of me to toss a word around that I don't fully understand.) conserved by acceleration of RM. Ship slows down a little or not at all (photons momentum equals RM momentum and ship stays the same??? but ship now has less mass ) 2 reflected photons absorbed: Momenergy conserved by ship slowing down. 3 electricity used to further accelerate RM. ship slows down even more. I cannot begin to solve the math showing how much the ship slows down, or how much energy is required, or how much RM is required. I'm not even sure the physical model is correct. help. Kevin PS, I do appreciate your kind tutuledge Steve, I know it must be frustrating trying to pound knowledge into a head as thick as mine, especially through such a small bandwidth channel like this. From popserver Sun Dec 3 23:14:51 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5158" "Sun" "3" "December" "1995" "22:24:12" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "120" "Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA21840; Sun, 3 Dec 95 13:21:05 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA26247 (5.67b/IDA-1.5 for ); Sun, 3 Dec 1995 22:24:03 +0100 Message-Id: <199512032124.AA26247@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818032205.019 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sun, 03 Dec 1995 22:24:12 +0100 ReplyFrom : Timothy ReplyTo : Kelly Subject : Humans and stairs >Hold your arm out to you side. Tell me it takes no effort (energy) to hold >it there. Even if I could convince you that it took no energy to keep it there, you would probably say that the only possibility was that my feet got colder. But serious, it is not that easy to explain this easy in an other way than Steve and I did earlier. So let me ask you a question: Does it TAKE energy to walk down the stairs or does it GIVE energy? If it takes energy, would that not mean that walking up the stairs would give energy? And if it gives energy, why use people elevators or lifts? I'm not trying to make fun out of you, but I'm trying to point you at the errors in your theory. Since you probably are better at looking in yourself than I am, my hopes are that with these questions you solve the difficulties yourself. problems. Timothy =========================================================================== ReplyFrom : Timothy ReplyTo : Kelly Subject : Prelaunching >No, Kevins starship design is propelled by a photon (maser) beam. My >origional Explorer design is propelled by fusion powered mass drivers. I >call it an externally feed system since the fuel is thrown out ahead of the >ship by a launcher in Sol. (See my Explorer starship design page on the LIT >site.) Thats probably the central thing confusing you. Unless your >confusing the Explorer ship with the plasma mirror design I came up with more >recently. Ah, now I see. But you agreed that both prelaunching and taking-all-with-us takes the same amount of energy/fuel. But after understanding it, I think that that prelaunching is more economic with energy. >Figure out how much fuel it would take to run the reactors & engines enough >to accelerate the ship (but not its fuel) up to speed. I've started a calculation, but as far as I can see it now, this method is not much more efficient than the take-it-all-with-us method. Furthermore, prelaunching only works for acceleration, not for decelleration. >> It would be best if we could find a solution without using the interstellar >> particles, but at the same time we should keep in mind >> that we have to protect us against it. This may sound a >> bit contradictory but a general solution would be best. > >How about working out a high and low range based on the most and least mass >expected out there? That would be fine with me, but I have a feeling that using the ISM to break will not work. But OK, does anyone have the number of particles per cubic metre? =========================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >Don't understand you question. I was assuming it would depend on the mass, >but I didn't know how much mass that would be. I guess, I was having difficulties with the expression "I don't have a handle". >> Ions are particles too. They may have small masses, >> but if you have enough of them you could build a >> complete dragon-fly sail. > >I don't know which system would be lighter, but of course we couldn't build >the dragon-fly system, so thats kind of a mute point. We can't build a dragon-fly system? I don't agree with that. Just make a big (heavy) mirror and detach just before the Asimov is going to decelerate and the mirror is going to accelerate. >> Probably all the way in between. But that is not important >> here, because a reflection means transfer of momentum, >> and with it energy. Since the plasma will be accelerated >> a lot, it will retrieve a lot of energy. > >Do you mean absorb a lot of energy? That is a problem with a drop mirrow or >plasma mirror idea. But as long as you can do it and get thrust to >decelerate the ship (the big problem in al this), it might work well enough >to get us somewhere. (Assuming the whole thing doesn't melt the ship!) No, I meant retrieving energy in the form of kinetic energy: The plasma is accelerated much as the photons are reflected on it. >On the contrary. I'm trying to take a very complicated system and make it >simpler. Notice I don't have the massive microwave to electric power >converters of Kevin's origional drive system. Nor do I have the ultra exotic >A.I. controled active structure of Forwards drop reflector sail. Forwards >design would have had to steer itself, while steering the reflected beam back >to the main ship, while tracking the main ship over interstellar distences. > This is not easy, and it is REALLY pushing the envelope of probable 2050 >technologies! Are you sure that you know how the Dragon-fly or retro-reflection method works? Because I don't see why a plasma mirror is easier than a solid mirror. >On the other hand my plasma mirror idea would all take place in the area of >the ship, and be directly controlable by the ship. Assuming it wasn't mass >or energy prohibative, it would clearly be the prefered system. (Assuming it >would work of course.) Indeed, if it wasn't for the mass or energy it would certainly have a pre. But I'm quite certain that especially the mass would be the problem. From popserver Sun Dec 3 23:15:05 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1224" "Sun" "3" "December" "1995" "23:48:23" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "31" "Engineering newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA25328; Sun, 3 Dec 95 14:45:03 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA00758 (5.67b/IDA-1.5 for ); Sun, 3 Dec 1995 23:48:16 +0100 Message-Id: <199512032248.AA00758@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818032205.027 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering newsletter Date: Sun, 03 Dec 1995 23:48:23 +0100 ReplyTo : Kevin ReplyFrom : Timothy Subject : Dragonfly? >I think this is what Kelly was trying to get at with his plasma mirror, >but this puts the mirror inside the ship. I realize that I'm talking >about some very very complicated twists and turns, but just answer the >following question. is this system physically possible? does it >preserve momenergy, and does the ship slow down. we can worry about the >merely difficult engineering tasks later. Yes, it looks much like it, and I have the same comment, why not use a simple massive mirror that works according to the dragon-fly principle. >here's how I see it breaking down, > >1 photons reflecting off RM: > >Momenergy (very dangerous of me to toss a word around that I don't fully >understand.) conserved by acceleration of RM. Ship slows down a little or >not at all (photons momentum equals RM momentum and ship stays the >same??? but ship now has less mass ) > >2 reflected photons absorbed: >Momenergy conserved by ship slowing down. > >3 electricity used to further accelerate RM. ship slows down even more. It would be better not to absorb the photons, but reflect them right away. Steve showed that a long time ago. From popserver Sun Dec 3 23:14:59 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["688" "Sun" "3" "December" "1995" "14:30:47" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "14" "Re: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from wolfe.net (mail1.wolfe.net) by efn.efn.org (4.1/smail2.5/05-07-92) id AA24281; Sun, 3 Dec 95 14:22:26 PST Received: from sea-ts2-p48.wolfenet.com (sea-ts2-p48.wolfenet.com [204.157.98.166]) by wolfe.net (8.7/8.7) with SMTP id OAA20330; Sun, 3 Dec 1995 14:30:47 -0800 (PST) Message-Id: <199512032230.OAA20330@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818032205.023 From: rddesign@wolfenet.com To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sun, 3 Dec 1995 14:30:47 -0800 (PST) >We can't build a dragon-fly system? I don't agree with that. Just make a big >(heavy) mirror and detach just before the Asimov is going to decelerate and >the mirror is going to accelerate. Lookout, here comes the novice again. :-) If yoyu are thinking about dicarding the mirror or anything else, think about dumping it as Reaction Mass into the drive and use it to help slow this puppy down. Along with mass brought along just for this purpose a dent could be made in slowing the ship. Deploy a second "sail/mirror" behind the ship to feed solar energy from TC into the drive to assist also. think about simpler soultions. The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Mon Dec 4 06:55:54 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["4219" "Mon" "4" "December" "1995" "00:29:18" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<951204002917_124214983@mail02.mail.aol.com>" "112" "Re: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from mail02.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA11586; Sun, 3 Dec 95 21:26:54 PST Received: by mail02.mail.aol.com (8.6.12/8.6.12) id AAA20779; Mon, 4 Dec 1995 00:29:18 -0500 Message-Id: <951204002917_124214983@mail02.mail.aol.com> X-UIDL: 818059876.006 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Mon, 4 Dec 1995 00:29:18 -0500 Subj: Engineering Newsletter Date: Sun, Dec 3, 1995 4:24 PM EST From: T.L.G.vanderLinden@student.utwente.nl X-From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl ReplyFrom : Timothy ReplyTo : Kelly Subject : Humans and stairs >Hold your arm out to you side. Tell me it takes no effort (energy) to hold >it there. >> Even if I could convince you that it took no energy to keep >> it there, you would probably say that the only possibility >> was that my feet got colder. Don't bother. I refused to get into an argument over levitating arms. >> Does it TAKE energy to walk down the stairs or does it GIVE energy? Actually both take energy since your accelerating and decelerating masses of your body. Though obviously going down you don't need to bost yourself up a gravity/potential energy well. =========================================================================== ReplyFrom : Timothy ReplyTo : Kelly Subject : Prelaunching >No, Kevins starship design is propelled by a photon (maser) beam. My >origional Explorer design is propelled by fusion powered mass drivers. I >call it an externally feed system since the fuel is thrown out ahead of the >ship by a launcher in Sol. (See my Explorer starship design page on the LIT >site.) Thats probably the central thing confusing you. Unless your >confusing the Explorer ship with the plasma mirror design I came up with more >recently. >> Ah, now I see. But you agreed that both prelaunching and taking-all-with-us >> takes the same amount of energy/fuel. But after understanding it, I think >> that that prelaunching is more economic with energy. Energy total yes. Energy on the ship, no. Since the ship power requierments are the show stoper of the system.. >> Furthermore, prelaunching only works for acceleration, not for decelleration. Agreed, but then you can say the same thing about photon sailers. >> It would be best if we could find a solution without using the interstellar >> particles, but at the same time we should keep in mind >> that we have to protect us against it. This may sound a >> bit contradictory but a general solution would be best. > >How about working out a high and low range based on the most and least mass >expected out there? >> >That would be fine with me, but I have a feeling that using the ISM to break >> >will not work. But OK, does anyone have the number of particles per cubic metre? I listed some assumptions on my Explorer Web page in LIT. I think bottom assumption was a hydrogen atom every cubic centameter or 4. =========================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >Don't understand you question. I was assuming it would depend on the mass, >but I didn't know how much mass that would be. >> I guess, I was having difficulties with the expression "I don't have a handle". Sorry for the slang. English to englist translation. I don't know what the answer is. >> Ions are particles too. They may have small masses, >> but if you have enough of them you could build a >> complete dragon-fly sail. > >I don't know which system would be lighter, but of course we couldn't build >the dragon-fly system, so thats kind of a mute point. >> >>We can't build a dragon-fly system? I don't agree with that. Just make a big >> >>(heavy) mirror and detach just before the Asimov is going to decelerate and >> >>the mirror is going to accelerate. Sorry that won't work. As the outer mirror moves away from the ship it has to continuosly reshape itself to refocus on the smaller catcher mirror/sail on the ship. Also without the anchor on the ship it will tend to flutter and shift off course due to slight variations in beam, ISM, mirror reflectvity, seperation torque, etc.. This of course ignores the fact the sail isn't rigid, and will tend to crumple once its free of the ship. Forward realized this, thats why he had an army of autonomus robots go with the outer sail to keep it working. Kelly From popserver Mon Dec 4 07:16:09 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2828" "Sun" "3" "December" "1995" "23:14:09" "-0800" "Steve VanDevender" "stevev@efn.org" nil "60" "Re: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA15476; Sun, 3 Dec 95 23:09:53 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id XAA11724; Sun, 3 Dec 1995 23:14:09 -0800 Message-Id: <199512040714.XAA11724@tzadkiel.efn.org> In-Reply-To: <199512032230.OAA20330@wolfe.net> References: <199512032230.OAA20330@wolfe.net> X-UIDL: 818061104.000 From: Steve VanDevender To: rddesign@wolfenet.com Cc: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden), KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sun, 3 Dec 1995 23:14:09 -0800 rddesign@wolfenet.com writes: > >We can't build a dragon-fly system? I don't agree with that. Just make a big > >(heavy) mirror and detach just before the Asimov is going to decelerate and > >the mirror is going to accelerate. > > Lookout, here comes the novice again. :-) > If yoyu are thinking about dicarding the mirror or anything else, think > about dumping it as Reaction Mass into the drive and use it to help slow > this puppy down. Along with mass brought along just for this purpose a dent > could be made in slowing the ship. Deploy a second "sail/mirror" behind the > ship to feed solar energy from TC into the drive to assist also. > think about simpler soultions. > The best Beads come from RD Designs. > Ric & Denisse Hedman To quickly summarize an earlier discussion: The novel _Flight of the Dragonfly_ by physicist Robert L. Forward describes a starship, called the Dragonfly, which uses a unique lightsail design. During the boost phase of the trip, the ship uses a single large lightsail to accelerate, powered by lasers from the Solar system. At the end of the boost phase, the large sail is detached but left intact. A smaller forward-facing sail is deployed on the ship. During the deceleration phase, the lasers remain aimed towards the large sail (with ship ship and small sail shadowing part of it), which is designed to carefully focus the incident light back towards the small sail. With this design, an ship can be accelerated and decelerated with lightsails powered from the system of origin. It's also pretty clean in terms of its physical behavior, although the task of focusing light from the forward sail to the retro sail is not trivial as the distances involved are very large. It is likely to be more efficient than using the sail material as reaction mass since it uses photons (already demonstrated to be a better form of "reaction mass" than any other material) exclusively for transferring momentum. The design still has some difficulties, the biggest of which is the focusing problem. Heavy use of such spacecraft would leave drifting relativistic-speed light sails zooming around the universe. These would gradually disintegrate from interactions with interstellar gas, if of course they didn't disintegrate while in use. The power coming from the forward sail gets pretty red-shifted near the end of the trip when the ship is nearly stopped; like most relativistic light-sail designs you have to turn up the power over the course of the trip. In some ways I think the Dragonfly sail (if I was sure that Forward invented it, I would call it the Forward sail both in his honor and for the mnemonic appropriateness) is a much cleaner and possibly more effective design than any of the other externally-powered ship designs that have been considered so far. From popserver Mon Dec 4 09:37:15 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2224" "Mon" "4" "December" "1995" "01:35:33" "-0800" "Steve VanDevender" "stevev@efn.org" nil "49" "Re: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA20152; Mon, 4 Dec 95 01:31:15 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id BAA12035; Mon, 4 Dec 1995 01:35:33 -0800 Message-Id: <199512040935.BAA12035@tzadkiel.efn.org> In-Reply-To: <951204002917_124214983@mail02.mail.aol.com> References: <951204002917_124214983@mail02.mail.aol.com> X-UIDL: 818069569.000 From: Steve VanDevender To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Mon, 4 Dec 1995 01:35:33 -0800 KellySt@aol.com writes: > ReplyFrom : Timothy > ReplyTo : Kelly > Subject : Humans and stairs > > >Hold your arm out to you side. Tell me it takes no effort (energy) to hold > >it there. > > >> Even if I could convince you that it took no energy to keep > >> it there, you would probably say that the only possibility > >> was that my feet got colder. > > Don't bother. I refused to get into an argument over levitating arms. > > >> Does it TAKE energy to walk down the stairs or does it GIVE energy? > > Actually both take energy since your accelerating and decelerating masses of > your body. Though obviously going down you don't need to bost yourself up a > gravity/potential energy well. Tell me this, Kelly. Given a rod of mass m and height h, standing vertically in a uniform gravitational field that produces acceleration g, what is the power in watts of heat energy dissipated by the rod? I'll also accept a formula that gives the dissipation of an infinitesimal element at the bottom of the rod; it would be sufficient for determining the power dissipated by any section of the rod by integrating the formula over that section. Pointers to experiments that have been done to demonstrate this effect would also be helpful in convincing me that it's real. I'm also curious about whether you'd draw a distinction between that rod standing in a gravity field and the same rod clamped horizontally in a vise -- in either case the rod is under compression forces, but the rod clamped in a vise is not getting its compression from the gravity field. Does the rod in the vise also dissipate heat for as long as it's under compression? Why or why not? If it does, where does the energy come from, and what is the relationship between the tension or compression and the heat dissipated by the rod? Like Timothy, I'm not doing this to make fun of you. You are stating an opinion that is at odds with accepted laws of physics, at least as we understand them. If your belief that standing structures dissipate heat because of tension or compression forces has any truth, then it should be possible to demonstrate the effect experimentally and produce a theory that explains the effect. From popserver Mon Dec 4 09:42:19 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8602" "Mon" "4" "December" "1995" "01:40:36" "-0800" "Steve VanDevender" "stevev@efn.org" nil "202" "Re: Summarry of the momentum wars and idea." "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA20238; Mon, 4 Dec 95 01:36:20 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id BAA12049; Mon, 4 Dec 1995 01:40:36 -0800 Message-Id: <199512040940.BAA12049@tzadkiel.efn.org> In-Reply-To: References: <199512030256.SAA02132@tzadkiel.efn.org> X-UIDL: 818069874.000 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Mon, 4 Dec 1995 01:40:36 -0800 Kevin C. Houston writes: > Half formed idea follows: (modifications/analysis welcomed) > > > __________ > |RM inlet > ship's core /"/ > Power from Sol ______________/"/________ > ~~~~~~~~~~~~~~~~~~~~~~============"="="="="="="="="="" exhaust and power > ~~~~~~~~~~~~~~~~~~~~~~============="="="="="="="="="=" > ~~~~~~~~~~~~~~~~~~~~~~============"="="="="="="="="="" > ______________ _________ > \"\ > \"\ > |RM inlet > > > ~ Photons going one way > = photons going both directions (canceling? hope not) > " Reaction Mass > > my question is this: > does the ship slow down? As drawn, I don't think so. The reason a rocket accelerates is that it reacts some material to produce pressurized gas in a vessel that is open on one end. The gas escapes from the opening, and the rocket moves in reaction because the pressure on the vessel (which is attached to the rocket) is asymmetric -- constant everywhere except at the opening. In microscopic terms all of the molecules that get forward momentum from the reaction bounce off the forward side of the vessel and transfer momentum to it. What you've built is sort of like a rocket that's a big open tube. Once the reaction mass is dumped into the tube, it's accelerated by the maser, but there's no way for it to transfer momentum with the ship. A chemical rocket built that way would just spew flame out each end of the pipe and not move. Here, whether the reaction mass absorbs or reflects the laser energy, it does so independently of the ship. A simple analogy might be to consider the difference between you throwing a baseball in zero-g and drifting backwards from the reaction, or placing a baseball in front of you and having someone shoot it with a rifle. The baseball goes flying away but you don't move from where you started. > I think it should. (but I've been wrong before) before the interaction, > the ship and the RM were traveling to the right with some speed V. after > the interaction, the RM is traveling at a greatly increased speed to the > right, and the photon beam is traveling to the left. (complete reflection > -- don't ask me how, just assume it for the moment.) I'll allow the hypothetical complete reflection, and your analysis of this part looks correct. The reaction mass accelerates but the ship doesn't slow down. > Now absorb the photon beam and convert it to electricity. > (the ship should act as though the photons came from Tau Ceti, slowing > even more.) -- again, we either need a magical one-way absorber at the > ~/= interface (~ photons enter from the left, = photons are absorbed from > the right), or a complicated series of reflectors. or we have to abandon > the photons capture and just let all that lovely energy zing back to earth. > > the electricity (if we can capture it) can then be used to power a lineac, > acellerating the plasma stream even more. which definitly would slow the ship > > I think this is what Kelly was trying to get at with his plasma mirror, > but this puts the mirror inside the ship. I realize that I'm talking > about some very very complicated twists and turns, but just answer the > following question. is this system physically possible? does it > preserve momenergy, and does the ship slow down. we can worry about the > merely difficult engineering tasks later. In principle this is really much like the Dragonfly two-piece lightsail. It's OK to reflect the photons backwards and use them to decelerate as long as you give the forward momentum from the original forward-moving photons to something, whether it's the Dragonfly forward sail or the reaction mass you're throwing into the pipe. > here's how I see it breaking down, > > 1 photons reflecting off RM: > > Momenergy (very dangerous of me to toss a word around that I don't fully > understand.) conserved by acceleration of RM. Ship slows down a little or > not at all (photons momentum equals RM momentum and ship stays the > same??? but ship now has less mass ) My thinking is that you are right that the ship won't slow down. Momenergy is Taylor and Wheeler's invented term. Their rationale for creating the concept seemed to be: 1. Conservation of energy is a major principle of physics. 2. Conservation of momentum is a major principle of physics. 3. Momentum and energy are conserved independently of each other, so energy can be added as a fourth component to a momentum vector, and normal vector operations will preserve conservation of the components. 4. When using total (rather than kinetic) energy for an object, there is a geometrically compelling interpretation for the resulting "momenergy" vector -- it points in the same direction as the velocity vector of the object, and its Lorentz magnitude is equal to the mass (in Timothy's terms, "rest mass") of the object. They then use momenergy vectors as fundamental items in relativistic kinematics problems. Conservation is handled automatically by requiring that the sum of momenergy vectors of all the components of an interaction remains the same before and after any interaction. In simple problems where you use one spatial dimension and momenergy vectors are two-dimensional, you can even draw nice diagrams on paper to show relationships, which is handy for solving problems. I write full four-dimensional momenergy vectors as: [ energy x-momentum y-momentum z-momentum ] The Lorentz magnitude of this vector is: sqrt(energy^2 - x-momentum^2 - y-momentum^2 - z-momentum^2) A more leisurely-paced explanation of momenergy vectors is in Chapter 7 of Taylor and Wheeler's _Spacetime Physics_. Have you bought your copy yet? > 2 reflected photons absorbed: > Momenergy conserved by ship slowing down. This is OK too, given your previous assumptions. > 3 electricity used to further accelerate RM. ship slows down even more. This is actually a very interesting idea. A small problem is that accelerating the reaction mass forward means that any light reflected back from it will be lower in energy because of doppler-shifting, so you get less energy back to accelerate further reaction mass. > I cannot begin to solve the math showing how much the ship slows down, or > how much energy is required, or how much RM is required. I'm not even > sure the physical model is correct. > > help. Well, I can at least show you how I'd start laying out the solution using the methods I'm familar with. First, let's pick a frame for doing the analysis. I tend to like using a frame where the spacecraft is initially at rest. So in this frame, the ship has momenergy [ s 0 ] (since motion in only one dimension is necessary for this analysis, I'll use 2-d vectors), and photons with momenergy [ p p ] are being beamed to the ship. This gives us the first major constraint on the solution -- no matter what happens, the total momenergy after any interaction will be [ s+p p ]. The intended reaction is to eject some quantity of reaction mass r into the photon beam, diminishing the ship's mass to s-r. This reaction mass also reflects the photons backward (in your ideal case), and the ship absorbs them. So now we have a system with these momenergies: ship: [ se sp ] reaction mass: [ re rp ] We also have the relationships: The invariant mass of the ship after ejecting the reaction mass is the magnitude of its momenergy vector: (s - r)^2 = magnitude [ se sp ] = se^2 - sp^2 Similarly, the invariant mass of the ejected reaction mass is the magnitude of its momenergy vector: r^2 = magnitude [ re rp ] = re^2 - rp^2 The momenergy vectors of the system components after the reaction is the same as the sum of the components before the reaction: [ se sp ] + [ re rp ] = [ s 0 ] + [ p p ] = [ s+p p ] It's too late for me to want to work on solving this now, but hopefully with appropriate juggling several of these variables can be eliminated and the final result can be expressed in terms of the quantities we consider known: s, r, p. > Kevin > > PS, I do appreciate your kind tutuledge Steve, I know it must be > frustrating trying to pound knowledge into a head as thick as mine, > especially through such a small bandwidth channel like this. If I keep this up I'd better get tenure in the LIT Physics department :-). From popserver Mon Dec 4 10:07:40 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["3641" "Mon" "4" "December" "1995" "03:59:52" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "80" "Retro sailing difficulties" "^From:" nil nil "12" nil nil nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA21089; Mon, 4 Dec 95 01:57:18 PST Received: by maroon.tc.umn.edu; Mon, 4 Dec 95 03:59:53 -0600 Reply-To: Kevin C Houston In-Reply-To: <199512040714.XAA11724@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII X-UIDL: 818071394.000 From: Kevin C Houston Sender: Kevin C Houston To: Steve VanDevender Cc: rddesign@wolfenet.com, Timothy van der Linden , KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Retro sailing difficulties Date: Mon, 4 Dec 1995 03:59:52 -0600 (CST) To: all I think another problem with a retro reflective sail is that it puts an effective upper limit on acceleration and speed of the ship. I'm not sure what that limit is, but it must be substantially below 1 G accel, and far below C at turnaround. The whole idea with an externally fueled (either mass or photonic) ship was to keep gravity constant and get close to C. But observe what happens near turnaround if you do this with a retro reflective mirror. At turnaround, the ship and mirror are moving at .99 of C. Ship and mirror are detached. outer sail begins to accelerate even more. the outer ring sail begins to get inefficient _twice_. Once, when it sees the maser from earth redshifted, and twice, when the ship sees the reflected beam redshifted _again_. At the limit, it begins to look like Steve's two mirror puzzle. We'd get almost nothing out of the mirror as it asymtotically approached the speed of light. The plasma mirror avoids these difficulties. Since the mirror is constantly being renewed at the ship's speed, the primary reflection gets more and more efficient as the ship slows down. Also, this allows us to use the plasma mirror as reaction mass at the same time we're using it for retro reflection. plasma exhaust may not be the most efficient in the universe, but it's the best I can find if you want to get near C. How to aim a maser up the butt of the ship from twelve light years away: Simple really, just reflect the maser off the main sail with the focus at one end of the core. a second mirror there re-reflects the maser up the central core. (Foreward shows in his design a way to make diseparate beams enter into a colimator, and emerge as one coherent beam.) How to support a large sail structure hanging off the ship. it supports itself, because it is a parabolic shape, the reflection off of the innermost part of the main sail imparts almost no perpendicular force component. the beam that reflects off the outermost part of the main sail imparts a larger perpendicular (to the ships direction of flight) component and thus keeps the sail "inflated". How to make the plasma go out one end only: a transparent (to whatever energy beam we use) plate on the back end would allow the energy in, but prevent the the plasma from escaping no furling or unfurling of the main sail is required, the whole thing can be controlled by the secondary mirror. if it is retracted, then the maser bounces off the main sail, imparting thrust to the ship. Without a second mirror to bounce off of, the ship accelerates away from Sol. To begin slow-down, (can't even call it turnaround anymore, things sure have changed.) the secondary mirror is extended to intercept the reflected beam and send it into the core. The beam hits a wall of plasma, bounces off, and hits an absorber. (it can't be bounced back, because then it would just hit the plasma again, and be going in the wrong direction -- back toward Sol) The absorbed energy is then used to power ship's systems and further accelerate the plasma. if anyone can figure out how to bounce the maser beam back toward TC after it hits the plasma, I'll gladly scrap the accelerating-the-plasma with-the-converted-energy idea. which would save us from having to use microwaves, and help out with our heat load. Kevin P.S. to Steve. I just got your analysis of the design as i was about to send this. seems reasonably well laid out. BTW, what is the ISBN of Taylor and Wheeler's book? that will help me to order it. It will be a week or so before i can do any detailed work on it. From popserver Mon Dec 4 21:29:05 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4216" "Mon" "4" "December" "1995" "12:27:43" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "90" "Re: Retro sailing difficulties" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA23250; Mon, 4 Dec 95 03:24:32 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA09586 (5.67b/IDA-1.5 for ); Mon, 4 Dec 1995 12:27:38 +0100 Message-Id: <199512041127.AA09586@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818112256.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Retro sailing difficulties Date: Mon, 04 Dec 1995 12:27:43 +0100 To: Kevin >I think another problem with a retro reflective sail is that it puts an >effective upper limit on acceleration and speed of the ship. I'm not >sure what that limit is, but it must be substantially below 1 G accel, >and far below C at turnaround. The whole idea with an externally fueled >(either mass or photonic) ship was to keep gravity constant and get close >to C. > >But observe what happens near turnaround if you do this with a retro >reflective mirror. > >At turnaround, the ship and mirror are moving at .99 of C. Ship and >mirror are detached. outer sail begins to accelerate even more. >the outer ring sail begins to get inefficient _twice_. Once, when it sees >the maser from earth redshifted, and twice, when the ship sees the >reflected beam redshifted _again_. I hadn't thought of that second shift... >At the limit, it begins to look like Steve's two mirror puzzle. We'd get >almost nothing out of the mirror as it asymtotically approached the speed >of light. But in the end it is also easier to decelerate: E=0.5 m v^2 The difference between v=1001 and v=1000 is dE=2001 while the difference between v=101 and v=100 is dE=201. Of course this same thing happens during acceleration: Only then more energy is needed. And that is not only because of the relativistic effects! >The plasma mirror avoids these difficulties. Since the mirror is >constantly being renewed at the ship's speed, the primary reflection gets >more and more efficient as the ship slows down. Yes but don't forget that the plasma gives also a serious redshift during the reflection. Also there is a finite time between replenishing the plasma and the reflection of light on that same plasma. This means the Asimov has decelerated a bit and that means the second redshift. It may be small, but it happens many many many times! Besides that, a lot of extra mass is needed to replenish the plasma. This extra mass has to be decelerated too! (Of course it get less during replenishing). Although I haven't done any calculations, I'm sure that a lot of mass is needed and my physics intuition tells me that the whole thing ends up needing the same energies as the dragon-fly. >Also, this allows us to use the plasma mirror as reaction mass at the >same time we're using it for retro reflection. plasma exhaust may not be >the most efficient in the universe, but it's the best I can find if you >want to get near C. If you use it as reaction-mass, that means that you need energy that comes from the Asimov, which it doesn't have! Also making the plasma move faster gives an even worse redshift. (If you think you can use the power of the maserbeam to accelerate the reaction-mass, then you are wrong) >How to aim a maser up the butt of the ship from twelve light years away: > >Simple really, just reflect the maser off the main sail with the focus at >one end of the core. a second mirror there re-reflects the maser up the >central core. (Foreward shows in his design a way to make diseparate >beams enter into a colimator, and emerge as one coherent beam.) I don't get this, could you make an ASCII drawing? >no furling or unfurling of the main sail is required, the whole thing can >be controlled by the secondary mirror. if it is retracted, then the >maser bounces off the main sail, imparting thrust to the ship. Without a >second mirror to bounce off of, the ship accelerates away from Sol. >To begin slow-down, (can't even call it turnaround anymore, things sure >have changed.) the secondary mirror is extended to intercept the >reflected beam and send it into the core. The beam hits a wall of >plasma, bounces off, and hits an absorber. (it can't be bounced back, >because then it would just hit the plasma again, and be going in the >wrong direction -- back toward Sol) That won't be bad, because we can use it again! (Of course more redshifted) >P.S. to Steve. I just got your analysis of the design as i was about to >send this. seems reasonably well laid out. BTW, what is the ISBN of >Taylor and Wheeler's book? that will help me to order it. It will be a >week or so before i can do any detailed work on it. ISBN 0-7167-2327-1 Timothy From popserver Mon Dec 4 21:29:56 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2177" "Mon" "4" "December" "1995" "17:35:00" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "60" "" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA04375; Mon, 4 Dec 95 08:31:27 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13158 (5.67b/IDA-1.5 for ); Mon, 4 Dec 1995 17:34:58 +0100 Message-Id: <199512041634.AA13158@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818112256.017 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: stevev@efn.org Subject: Date: Mon, 04 Dec 1995 17:35:00 +0100 Hi Steve, Imagine two electrically charged plates, both the positively charged. These two plates are on top of each other in a gravitational field: +++++++++++++++++++ Plate 1 gravity force || +++++++++++++++++++ Plate 2 \/ -------------------------------- //////////////////////////////// Solid floor Q:Why do the plates stay apart? A:Because of the electrical field. Q:But what is an electrical field and how does it propagate? A:Photons are the cariers of the electrical field. Q:So there are photons going up and down the plates? A:Yes and no, there are virtual photons going up and down. Q:What are virtual photons? A:These are photons that have a momentum that does not correspond to its energy. They can exist due to the uncertainty principle: dp*dx=h/(4 pi) What am I trying to say? Although this situation is static (the amount of virtual photons going up equals the amount going down) there is an exchange of something. One could also say that there is just a electric field, but even then there should be something that keeps the field the way it is. It may be that this is one of the things why Kelly has a hard time understanding that it no energy is released when an object is standing on the floor. >>> If a static structure had to dissipate energy continuously to >>> remain standing, where would such energy come from? Why doesn't >>> your house fall down? Where are the batteries? >> >>The energy is coming from the gravitational attraction of the earth. It is >>disapated as heat in the structure of the house. In a structure under heavy >>loads (too heavy) you can feel the heat in the structure. > >Really? So when does the earth run out of gravity? Of course Kelly is wrong, but one could say that there is an exchange (of energy?) between the house and the Earth. The total exchange is of course zero, but in the mean time a lot of interactions are going on. Saying that there would happen nothing would not make much sense, because then Kelly is right asking what keep space-time curved. Timothy P.S. This letter is only send to you. From popserver Mon Dec 4 21:29:58 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["5186" "Mon" "4" "December" "1995" "17:34:56" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" "<199512041634.AA13144@student.utwente.nl>" "128" "Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA04398; Mon, 4 Dec 95 08:31:48 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13144 (5.67b/IDA-1.5 for ); Mon, 4 Dec 1995 17:34:51 +0100 Message-Id: <199512041634.AA13144@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818112256.018 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Mon, 04 Dec 1995 17:34:56 +0100 ReplyFrom : Timothy ReplyTo : Kelly Subject : Humans and stairs >> Does it TAKE energy to walk down the stairs or does it GIVE energy? > >Actually both take energy since your accelerating and decelerating masses of >your body. Though obviously going down you don't need to bost yourself up a >gravity/potential energy well. When walking downstairs most of the accelerating is done by gravity, so that doesn't make you tired. Decelerating is done by the steps, so that does not take energy either. How do you respond to this? =========================================================================== ReplyFrom : Timothy ReplyTo : Kelly Subject : Using the SIM >I listed some assumptions on my Explorer Web page in LIT. I think bottom >assumption was a hydrogen atom every cubic centameter or 4. Now the question what are we going to do with the hydrogen? First catch it and decelerate a bit. Then use it both as fuel and reaction mass to decelerate even more. 4 per cubic centimetre --> 4E6 per cubic metre How much would we scoop? Total deceleration length: 2 ly = roughly 2E16 metres. 2E16*4E6*surface_of_the_scoop=8E22 hydrogen atoms per square metre of scooping area during the total deceleration. Thats a little more than one tenth MOL! and has a mass equivalent of: 0.0001 kilogram. This value seems to be too small to be useful! Unless we are planning a scoop of more than 1000 kilometres in radius. (Earth has a radius of 6500 kilometres) =========================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >Sorry that won't work. As the outer mirror moves away from the ship it has >to continuosly reshape itself to refocus on the smaller catcher mirror/sail >on the ship. I don't think refocussing is necessary, the mirror itself can be just a flat mirror so the reflected beam is nothing different than the beam from Earth. >Also without the anchor on the ship it will tend to flutter and >shift off course due to slight variations in beam, ISM, mirror reflectvity, >seperation torque, etc.. This of course ignores the fact the sail isn't >rigid, and will tend to crumple once its free of the ship. Of course the mirror has it's own "gyro-system" it can compensate slight movements by using a small side reflectors. The same principle would be used when the Asimov is accelerated by a beam. >Forward realized this, thats why he had an army of autonomus robots go with >the outer sail to keep it working. The mirror will be quite heavy so that it doesn't start moving too fast. (what is fast...) Most of that mass can be used as shielding for the mirror. Of course this whole thing would make the Asimov about twice as heavy. But that seems to be the price of any solution for deceleration. =============================================================================== ReplyTo : All ReplyFrom : Timothy Subject : nanoAI About AI and nanotech. If AI and nanotech would be sufficiently advanced in about 40 years. One or more small vessels could be send to TC all with their own fuel to decelerate. These small vessels would contain AI and nanotech or even a combination of both. This nanoAI could build the same facilities on TC that would "create" the energy for the Asimov on Earth. The advantage is that the small vessels would use much less energy to make the trip. After nanoAI has build the facilities, accelerating and decelerating the Asimov would be the same and make the whole design a lot easier. =============================================================================== ReplyTo : Steve ReplyFrom : Timothy Subject : Why use the Dragonfly >In some ways I think the Dragonfly sail (if I was sure that >Forward invented it, I would call it the Forward sail both in his >honor and for the mnemonic appropriateness) is a much cleaner and >possibly more effective design than any of the other >externally-powered ship designs that have been considered so >far. Indeed it doesn't need massive engines or difficult energy transformations. The only problem may be pointing the mirrors and beams acurately enough. What I don't see is why the mirror can't be flat. Why does it need a focusing action? As far as I can see problems about redshifts always arise if one tries to use the energy coming from Earth to decelerate the Asimov. =============================================================================== ReplyTo : Steve ReplyFrom : Timothy Subject : Lost letter? Steve, I haven't heard it from you, yet: Do we agree that at least between us the word relativistic mass is merely an other word for relativistic energy? Also in my letter of november 29th, I replied to you: >Yes, this is also true. Hot objects are heavier than cold ones >(although not by an amount we have equipment to measure). A >mirrored box full of photons is heavier than the empty box. And it doesn't matter if they all move parallel and in the same direction all the time, right? Here is another one: If two particles feel the gravity of each other, then they are heavier together than if they are separate because of the extra gravitational energy. From popserver Tue Dec 5 00:51:57 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1198" "Mon" "4" "December" "1995" "16:49:04" "-0800" "Steve VanDevender" "stevev@efn.org" nil "31" "Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA03002; Mon, 4 Dec 95 16:44:43 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id QAA13996; Mon, 4 Dec 1995 16:49:04 -0800 Message-Id: <199512050049.QAA13996@tzadkiel.efn.org> In-Reply-To: <199512041634.AA13144@student.utwente.nl> References: <199512041634.AA13144@student.utwente.nl> X-UIDL: 818124447.000 From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Mon, 4 Dec 1995 16:49:04 -0800 Timothy van der Linden writes: > ReplyTo : Steve > ReplyFrom : Timothy > Subject : Lost letter? > > Steve, I haven't heard it from you, yet: Do we agree that at > least between us the word relativistic mass is merely an other > word for relativistic energy? What you call "relativistic energy" or "relativistic mass" I call energy. I reserve the term mass for invariant mass. I believe this avoids confusion. > Also in my letter of november 29th, I replied to you: > > >Yes, this is also true. Hot objects are heavier than cold ones > >(although not by an amount we have equipment to measure). A > >mirrored box full of photons is heavier than the empty box. > > And it doesn't matter if they all move parallel and in the same direction > all the time, right? Even if the photons all move parallel in the same direction, the combination of the photons and the box is more massive than the box alone, even though the photons alone have no mass. > Here is another one: If two particles feel the gravity of each other, then > they are heavier together than if they are separate because of the extra > gravitational energy. I do not have the knowledge to answer this. From popserver Tue Dec 5 01:02:27 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["914" "Mon" "4" "December" "1995" "17:01:13" "-0800" "Steve VanDevender" "stevev@efn.org" nil "19" "Retro sailing difficulties" "^From:" nil nil "12" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA03689; Mon, 4 Dec 95 16:56:51 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.2/8.7.2) id RAA14024; Mon, 4 Dec 1995 17:01:13 -0800 Message-Id: <199512050101.RAA14024@tzadkiel.efn.org> In-Reply-To: References: <199512040714.XAA11724@tzadkiel.efn.org> X-UIDL: 818125070.002 From: Steve VanDevender To: Kevin C Houston Cc: Steve VanDevender , rddesign@wolfenet.com, Timothy van der Linden , KellySt@aol.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Retro sailing difficulties Date: Mon, 4 Dec 1995 17:01:13 -0800 Kevin C. Houston writes: > The plasma mirror avoids these difficulties. Since the mirror is > constantly being renewed at the ship's speed, the primary reflection gets > more and more efficient as the ship slows down. > > Also, this allows us to use the plasma mirror as reaction mass at the > same time we're using it for retro reflection. plasma exhaust may not be > the most efficient in the universe, but it's the best I can find if you > want to get near C. I don't think you could think of this as reaction mass as much as simply throwing out new mirrors continually so you have a backwards-reflecting mirror that stays near the speed of the ship. There is also advantage to decelerating a ship that is gradually decreasing in mass. You could just as easily talk about hucking out new mirrors periodically, rather than trying to make a plasma that has these magical reflective properties. From popserver Wed Dec 6 08:04:32 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1651" "Tue" "5" "December" "1995" "23:54:25" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "31" "Re: Retro sailing difficulties" "^From:" nil nil "12" nil "Retro sailing difficulties" nil nil] nil) Received: from mail06.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA29168; Tue, 5 Dec 95 20:55:59 PST Received: by mail06.mail.aol.com (8.6.12/8.6.12) id XAA10544; Tue, 5 Dec 1995 23:54:25 -0500 Message-Id: <951205235424_45961101@mail06.mail.aol.com> X-UIDL: 818237001.008 From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org Cc: rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Retro sailing difficulties Date: Tue, 5 Dec 1995 23:54:25 -0500 >> if anyone can figure out how to bounce the maser beam back >> toward TC after it hits the plasma, I'll gladly scrap the >> accelerating-the-plasma with-the-converted-energy idea. >> which would save us from having to use microwaves, and >> help out with our heat load. Arange the catcher mirror so that it focuses the reflected maser beam (from the ring sail) on the plasma, but does not inact with the maser reflected back from the plasma. If that reflected maser beam hits a flat mirror (or a curved or conical mirror) that doesn't reflect it onto the ring sail. The reflection from the plasma will push backwards toward Sol. I thought of a problem with the ring sail thou. It would focus the maser ahead of the ship. To realize this think of the thrust vectors on the sail from the reflections, vs the vectors from the cables from the ship. If the thrust vector angles are angled more forward than the cables, they would pull the sail forward. Which would colapse the sail. Since the reflected maser beams would be angled ahead of the normal vector at the point of reflection (equal angles of incidence and reflection) They would focus even farther ahead of the ship. I had thought of a was of using another sail to reflect the masers back outward for collection behind the ship, but that would probably not work due to beam reflections off the plasma stream. I suppose you could have the beam interact with the injected plasma in front of the ship. This would blow the high energy plasma stream backwards toward the ship. For later reflection off a magnetically or electrostatically charged forward shield/pusher plate. Kelly From popserver Wed Dec 6 08:04:33 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4359" "Tue" "5" "December" "1995" "23:54:56" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "97" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Received: from emout05.mail.aol.com by efn.efn.org (4.1/smail2.5/05-07-92) id AA29177; Tue, 5 Dec 95 20:56:02 PST Received: by emout05.mail.aol.com (8.6.12/8.6.12) id XAA14724; Tue, 5 Dec 1995 23:54:56 -0500 Message-Id: <951205235454_45961665@emout05.mail.aol.com> X-UIDL: 818237001.009 From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 5 Dec 1995 23:54:56 -0500 ReplyFrom : Timothy ReplyTo : Kelly Subject : Using the SIM >I listed some assumptions on my Explorer Web page in LIT. I think bottom >assumption was a hydrogen atom every cubic centameter or 4. Now the question what are we going to do with the hydrogen? First catch it and decelerate a bit. Then use it both as fuel and reaction mass to decelerate even more. 4 per cubic centimetre --> 4E6 per cubic metre How much would we scoop? Total deceleration length: 2 ly = roughly 2E16 metres. 2E16*4E6*surface_of_the_scoop=8E22 hydrogen atoms per square metre of scooping area during the total deceleration. Thats a little more than one tenth MOL! and has a mass equivalent of: 0.0001 kilogram. This value seems to be too small to be useful! Unless we are planning a scoop of more than 1000 kilometres in radius. (Earth has a radius of 6500 kilometres) =========================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >Sorry that won't work. As the outer mirror moves away from the ship it has >to continuosly reshape itself to refocus on the smaller catcher mirror/sail >on the ship. >> I don't think refocussing is necessary, the mirror itself can >> be just a flat mirror so the reflected beam is nothing >> different than the beam from Earth. That would mean the catcher sail on the ship would be the same size as the reflector mirror. That would mean it would get more push forward from the dirrect beam from earth, than push back from the reflected beam from the mirror. Assuming of course the mirror flies sideway slightly so it isn't in the ships shaddow all the way to Tau. Of course if its off to one side you have to turn it so its reflections tracks the ship, so your back to the tracking problem. >Also without the anchor on the ship it will tend to flutter and >shift off course due to slight variations in beam, ISM, mirror reflectvity, >seperation torque, etc.. This of course ignores the fact the sail isn't >rigid, and will tend to crumple once its free of the ship. >> Of course the mirror has it's own "gyro-system" it can >> compensate slight movements by using a small side >> reflectors. The same principle would be used when the >> Asimov is accelerated by a beam. With enough accuracy to hit the retro sail at a distence of light years? ============================================================================== = ReplyTo : All ReplyFrom : Timothy Subject : nanoAI >> About AI and nanotech. If AI and nanotech would be >> sufficiently advanced in about 40 years. One or more >> small vessels could be send to TC all with their >> own fuel to decelerate. These small vessels would >> contain AI and nanotech or even a combination of both. >> This nanoAI could build the same facilities on TC that >> would "create" the energy for the Asimov on Earth. The >> advantage is that the small vessels would use much less >> energy to make the trip. After nanoAI has build the >> facilities, accelerating and decelerating the Asimov >> would be the same and make the whole design a lot easier. We still have no drive idea that could get a bit or small ship to Tau C. We've added the relyability problems of the AI and Nano systems to the project. After all, programs can crash, and nano's are made of complex molecules that might break down in the high radiation in transite. Assuming they get there in tact, what do we tel them to use for resources in a system we don't know anything about? How does a ship fly in two apposing beams? You can't turn eiather off. Since: you can't contact the ship to know what its doing in time, and don't want to fly to a system in the hopes the A.I's will turn the beam on when you expect. We also have extended the time of the project to us sustainable levels. Figure a quarter century after launch before a returning beam from Tau C. announces the decel system is compleated. Then a quarter century after that (50 years from the launch of the first nano ship), a beam from your starship announces you've started exploration. If the projects going to take that long you might as well wait untill you have a better drive system. For that matter. If the A.I's are good enough to build the decel gear. You might as well have them do the exploration and skip the human ship. From popserver Wed Dec 6 21:11:32 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5589" "Wed" "6" "December" "1995" "22:02:09" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "131" "Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Received: from student.utwente.nl (driene.student.utwente.nl) by efn.efn.org (4.1/smail2.5/05-07-92) id AA16443; Wed, 6 Dec 95 13:02:37 PST Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28198 (5.67b/IDA-1.5 for ); Wed, 6 Dec 1995 22:01:53 +0100 Message-Id: <199512062101.AA28198@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 818284229.000 From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Wed, 06 Dec 1995 22:02:09 +0100 Who anyone who likes a physics comic, try: http://www.cpedu.rug.nl/~N0642983/velcro.gif It's about 14 Kbyte ============================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >>> I don't think refocussing is necessary, the mirror itself can >>> be just a flat mirror so the reflected beam is nothing >>> different than the beam from Earth. > >That would mean the catcher sail on the ship would be the same size as the >reflector mirror. That would mean it would get more push forward from the >dirrect beam from earth, than push back from the reflected beam from the >mirror. Hmm, yes, but there seems to have a similar problem with the plasma mirror. But I've found a solution: /\ A / \ B Two mirrors A and B at a perpendicular angle /________\ /|__________|\ / || || \ || || || || || /\ \/ Beam from Earth Beam to Earth This design makes the total mirror about 3 times bigger. The beam from Earth should be directed mainly on mirror B so that the beam to the Earth (or from TC) is reflected mainly from A. The final result is that there are two beams next to each other, one is going up the other is going down. >Assuming of course the mirror flies sideway slightly so it isn't in >the ships shaddow all the way to Tau. Of course if its off to one side you >have to turn it so its reflections tracks the ship, so your back to the >tracking problem. With this new design the biggest tracking problem is removed. Furthermore the Asimov always has to follow the beam just as in the acceleration fase. >>Also without the anchor on the ship it will tend to flutter and >>shift off course due to slight variations in beam, ISM, mirror reflectvity, >>seperation torque, etc.. This of course ignores the fact the sail isn't >>rigid, and will tend to crumple once its free of the ship. > >>> Of course the mirror has it's own "gyro-system" it can >>> compensate slight movements by using a small side >>> reflectors. The same principle would be used when the >>> Asimov is accelerated by a beam. > >With enough accuracy to hit the retro sail at a distence of light years? 10 ly, 30 ly does it really matter? The minimum is 10 ly for any kind of beam-propulsion system. I wonder if an extra 20 ly makes that much difference. ============================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : nanoAI >We still have no drive idea that could get a bit or small ship to Tau C. We have ideas, the biggest problem is the enormous amounts of fuel that are needed. Lets say we use a take-all-fuel-with-you system. For matter&anti-matter fuel the ratio fuel:ship would be about 20:1 for small ships 1E4 1E5 kg this may be acceptable but for ships 1E8 or 1E9 kg its a completly different story. >We've added the relyability problems of the AI and Nano systems to the >project. After all, programs can crash, and nano's are made of complex >molecules that might break down in the high radiation in transite. Assuming >they get there in tact, what do we tel them to use for resources in a system >we don't know anything about? Indeed things can go wrong and will go wrong. So will things happen on a ship like the Asimov, only then people are endangered. High radiation as a cause of error can easely be prevented by sufficient shielding. We know that there will be asteroids and planets there. This means that all the basic materials should be present, so our mini factories have to find them an use them. >How does a ship fly in two apposing beams? You can't turn eiather off. > Since: you can't contact the ship to know what its doing in time, and don't >want to fly to a system in the hopes the A.I's will turn the beam on when you >expect. The beams should be slightly from parallel. Halfway the should cross, and the vessel using it has to change beams there. This means that it has to move "side-way" some 100-1000 km or so. It should be like changing rail-tracks by using a switch. >We also have extended the time of the project to us sustainable levels. > Figure a quarter century after launch before a returning beam from Tau C. >announces the decel system is compleated. Then a quarter century after that >(50 years from the launch of the first nano ship), a beam from your starship >announces you've started exploration. If the projects going to take that >long you might as well wait untill you have a better drive system. Supposing a significant better system is possible within 50 extra years, I think its worth the waiting. >For that matter. If the A.I's are good enough to build the decel gear. You >might as well have them do the exploration and skip the human ship. That is something completly different discussion: Why do we want to go there anyway. I was having a discussion with Nick Tosh about that, until his connection broke down. I can tell you, that I don't know why we want to go there so soon anyway. If you have an answer I'd like to know... For the AI and nano, if they will be as unreliable and unadvanced as you think, my guess is that the time isn't right for flying to TC anyway: If anything, and I mean anything goes wrong in a system that uses 1E17 Watts you are lost! It's not like you can cut the power any time you like. What I wrote about overheating is just a small example of the problems that go with these power streams. (And as far as I'm concerned that problem isn't solved yet) Timothy From popserver Sat Dec 9 05:41:15 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7364" "Fri" "8" "December" "1995" "21:34:28" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "197" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id VAA04907 for ; Fri, 8 Dec 1995 21:38:07 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id VAA06888; Fri, 8 Dec 1995 21:34:28 -0500 Message-ID: <951208213427_67925326@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu Subject: Re: Engineering Newsletter Date: Fri, 8 Dec 1995 21:34:28 -0500 Hi guys, a few web pages you might be interested in. Zenon suggested nanotech and A.I. might be a pre req for star travel. He also suggested for more info about significance of nanotech for space exploration. See the Molecular Manufacturing Shortcut Group page at: http://www.music.qub.ac.uk:80/~amon/IslandOne/MMSG/ --------------- For serious info on planing space flights, check out: > >http://oel-www.jpl.nasa.gov/basics/bsf.htm > Originally created as an internal JPL training document, the Basics of Spaceflight is comprehensive, medium level overview of a wide range of topics related to construction and operation of planetary spacecraft. The material is supposed to be extremely well written and unlike many NASA outreach and educational materials, has not been digested down to the 5th grade level. ----------------------- Larry Klaes Editor of SETIQuest Magazine recomends http://www.setiquest.com It is still under construction, but its trying to let you explore how a starship will interact while approaching light speed. It can be found at URL http://www.fourmilab.ch under the link cship. ---------------------------------------------------------------------- ============================================================================== ReplyTo: Timothy Subject : Plasma mirror >>> I don't think refocussing is necessary, the mirror itself can >>> be just a flat mirror so the reflected beam is nothing >>> different than the beam from Earth. > >>That would mean the catcher sail on the ship would be the same size as the >>reflector mirror. That would mean it would get more push forward from the >>dirrect beam from earth, than push back from the reflected beam from the >>mirror. >Hmm, yes, but there seems to have a similar problem with >the plasma mirror. Not really, Since the ring sail & catcher mirror are in the same place (attached to the ship) the ring sial would be geting the same energy (no energy drop due to r^2 losses.) >But I've found a solution: /\ A / \ B Two mirrors A and B at a perpendicular angle /________\ /|__________|\ / || || \ || || || || || /\ \/ Beam from Earth Beam to Earth > This design makes the total mirror about 3 times bigger. >The beam from Earth should be directed mainly on mirror B > so that the beam to the Earth (or from TC) is reflected >mainly from A. The final result is that there are two beams > next to each other, one is going up the other is >going down. Whats the advantage? Also you seem to asume the that the power beam will be as small as the miror? It sould be thousands of miles across. >>Assuming of course the mirror flies sideway slightly so it isn't in >>the ships shaddow all the way to Tau. Of course if its off to one side you >>have to turn it so its reflections tracks the ship, so your back to the >>tracking problem. >With this new design the biggest tracking problem is removed. Furthermore >the Asimov always has to follow the beam just as in the acceleration phase. I don't understand what your going for. >>Also without the anchor on the ship it will tend to flutter and >>shift off course due to slight variations in beam, ISM, mirror reflectvity, >>seperation torque, etc.. This of course ignores the fact the sail isn't >>rigid, and will tend to crumple once its free of the ship. > >>> Of course the mirror has it's own "gyro-system" it can >>> compensate slight movements by using a small side >>> reflectors. The same principle would be used when the >>> Asimov is accelerated by a beam. > >With enough accuracy to hit the retro sail at a distence of light years? >>10 ly, 30 ly does it really matter? The minimum is 10 ly for >> any kind of >> beam-propulsion system. I wonder if an extra 20 ly makes that much difference. ============================================================================== ReplyTo : Timothy Subject : nanoAI >>We still have no drive idea that could get a bit or small ship to Tau C. >We have ideas, the biggest problem is the enormous amounts >of fuel that are needed. Lets say we use a >take-all-fuel-with-you system. For matter&anti-matter fuel > the ratio fuel:ship would be about 20:1 for small ships 1E4 >1E5 kg this may be acceptable but for ships 1E8 or 1E9 kg >its a completly different story. Your taking hundreds of tons of antimatter! That is a stagering amount to manufacture, or even hold on to! >>We've added the relyability problems of the AI and Nano systems to the >>project. After all, programs can crash, and nano's are made of complex >>molecules that might break down in the high radiation in transite. Assuming >>they get there in tact, what do we tel them to use for resources in a system >>we don't know anything about? >Indeed things can go wrong and will go wrong. So will things happen on a >ship like the Asimov, only then people are endangered. >High radiation as a cause of error can easely be prevented by >sufficient shielding. People are mentally much more adaptable and relyable than any current Nano/A.I. systems. >We know that there will be asteroids and planets there. This >means that all the basic materials should be present, so our >mini factories have to find them an use them. Thats a big job if your the size of a virus. -------- >>We also have extended the time of the project to un sustainable levels. >> Figure a quarter century after launch before a returning beam from Tau C. >>announces the decel system is compleated. Then a quarter century after that >>(50 years from the launch of the first nano ship), a beam from your starship >>announces you've started exploration. If the projects going to take that >>long you might as well wait untill you have a better drive system. >Supposing a significant better system is possible within 50 > extra years, I think its worth the waiting. So will the backers. So the nano idea won't be launched, and the idea isn't feasable. >>For that matter. If the A.I's are good enough to build the decel gear. You >>might as well have them do the exploration and skip the human ship. >That is something completly different discussion: Why do we >want to go there anyway. I was having a discussion with Nick > Tosh about that, until his connection broke down. I can tell > you, that I don't know why we want to go there so soon >anyway. >If you have an answer I'd like to know... As I remember the idea of LIT was to see if we could think of some way we could build a starship in 2050 with probable technology of the day. Tau C was selected as a target to focus the groups attention on. >For the AI and nano, if they will be as unreliable and > unadvanced as you think, my guess is that the time isn't right >for flying to TC anyway: If anything, and I mean anything goes >wrong in a system that uses 1E17 Watts you are lost! It's not >like you can cut the power any time you like. What I wrote >about overheating is just a small example of the problems >that go with these power streams. (And as far as I'm >concerned that problem isn't solved yet) Agreed. I remember a demo where a steelwool pad was throw in a radar beam. It burned away in secounds. Very impresive! Especially to someone who might be thinking of riding such a beam for a couple decades. Kelly From popserver Sat Dec 9 17:40:31 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6788" "Sat" "9" "December" "1995" "17:38:50" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "173" "Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id IAA29840 for ; Sat, 9 Dec 1995 08:38:06 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11787 (5.67b/IDA-1.5 for ); Sat, 9 Dec 1995 17:38:48 +0100 Message-Id: <199512091638.AA11787@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Engineering Newsletter Date: Sat, 09 Dec 1995 17:38:50 +0100 ReplyTo : Kelly ReplyFrom : Timothy Subject : Plasma mirror >>>> I don't think refocussing is necessary, the mirror itself can >>>> be just a flat mirror so the reflected beam is nothing >>>> different than the beam from Earth. >> >>>That would mean the catcher sail on the ship would be the same size as the >>>reflector mirror. That would mean it would get more push forward from the >>>dirrect beam from earth, than push back from the reflected beam from the >>>mirror. > >>Hmm, yes, but there seems to have a similar problem with >>the plasma mirror. > >Not really, Since the ring sail & catcher mirror are in the same place >(attached to the ship) the ring sial would be geting the same energy (no >energy drop due to r^2 losses.) But would the beam from Earth not strike the ring sail? If not, please could you make an (ASCII)drawing, because then I don't understand how where the ring-sail and catcher mirror and the plasma are located. I don't use a ring-sail AND a catcher mirror, during deceleration, I have only one flat mirror directed to TC on the ship and a retro-mirror that is not coupled to the ship. A|----\ O-----------/ O Earth ----------- Beam from Earth \ / Retro-mirror ---- Beam from TC (Beam from Earth reflected by the retro-mirror) A| Asimov with a flat mirror >> This design makes the total mirror about 3 times bigger. >>The beam from Earth should be directed mainly on mirror B >> so that the beam to the Earth (or from TC) is reflected >>mainly from A. The final result is that there are two beams >> next to each other, one is going up the other is >>going down. >Whats the advantage? It overcomes the problem you mentioned: tracking. The only thing the Asimov has to do is move about 1000 kilometres to the left after it has uncoupled the retro-mirror. The result is that the mirror and the Asimov will move in the same direction during deceleration. >Also you seem to asume the that the power beam will be as small as the miror? >It sould be thousands of miles across. I indeed did, if the beam is much bigger than the mirror, that would really be a waste. If the radius of the beam is twice as big as the radius of the mirror that would mean a loss of 75% of the beam! But to overcome this if the beam is misplaced or bigger than the mirror, my design could be modified a bit: Beam that missed the mirror || || / || \ A / || \ B Two mirrors A and B at a perpendicular angle /__________________\ but at some distance from each other /|____________________|\ / || || || \ || || || || || || || /\ /\ \/ Beams from Earth Beam to Earth Although the mirrors are further apart, they still would be connected to each other, only the connections will not reflect much. >>>Assuming of course the mirror flies sideway slightly so it isn't in >>>the ships shaddow all the way to Tau. Of course if its off to one side you >>>have to turn it so its reflections tracks the ship, so your back to the >>>tracking problem. > >>With this new design the biggest tracking problem is removed. Furthermore >>the Asimov always has to follow the beam just as in the acceleration phase. > >I don't understand what your going for. See above. You said that a retro-mirror had tracking problems because it always had to be at an angle with the Asimov. My new design overcomes this problem ============================================================================== ReplyTo : Kelly ReplyFrom : Timothy Subject : nanoAI >>We have ideas, the biggest problem is the enormous amounts >>of fuel that are needed. Lets say we use a >>take-all-fuel-with-you system. For matter&anti-matter fuel >> the ratio fuel:ship would be about 20:1 for small ships 1E4 >1E5 kg this >may be acceptable but for ships 1E8 or 1E9 kg >>its a completly different story. > >Your taking hundreds of tons of antimatter! That is a stagering amount to >manufacture, or even hold on to! My assumptions are that making anti-matter in 50 years will be about 50% efficient. Of course I can't be sure of this, but why wouldn't it? (Rethorical question) Besides this efficiency, I wonder why you are so blaffed by these numbers. These numbers are just the sum of the energy needed during 1 or 2 years of acceleration. If we build a maser beaming station, a similar amount of energy is needed. The only thing you do when transferring energy to anti-matter is making it a bit more permanent. It probably is the easiest way to store such amounts of energy. So the moral is, anti-matter is merely an amount of energy that is easier to keep in storage. >People are mentally much more adaptable and relyable than any current >Nano/A.I. systems. You can't compare adaptability and reliable to CURRENT systems. That would be the same as to say that current engines would not work for our project and thus that it was not possible. >>We know that there will be asteroids and planets there. This >>means that all the basic materials should be present, so our >>mini factories have to find them an use them. > >Thats a big job if your the size of a virus. >From this I can conclude that I have a more optimistic view about nanotech and AI, then you do. Of course nanotech and AI are now in an early stage, but if 50 years ago, you had said what computers of today would be like, then they had laughed at you also. >>That is something completly different discussion: Why do we >>want to go there anyway. I was having a discussion with Nick >>Tosh about that, until his connection broke down. I can tell >>you, that I don't know why we want to go there so soon >>anyway. >>If you have an answer I'd like to know... > >As I remember the idea of LIT was to see if we could think of some way we >could build a starship in 2050 with probable technology of the day. Tau C >was selected as a target to focus the groups attention on. I know that, but I thought it was interesting to figure out why we want to go there. Is it just to have pissed on the ground there? Or is it because we want to colonize it? Or is it for scientific reasons? Or maybe all of them? All these things me be reasonable at first but, if you think a bit further, they make not much sense anymore... >Agreed. I remember a demo where a steelwool pad was throw in a radar beam. > It burned away in secounds. Very impresive! Especially to someone who >might be thinking of riding such a beam for a couple decades. I wish I could have seen it. Bear in mind that what you saw there was probably as very small example of what may be the case for the Asimov. Timothy From popserver Tue Dec 12 18:04:49 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10319" "Tue" "12" "December" "1995" "00:03:44" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "239" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id VAA28152 for ; Mon, 11 Dec 1995 21:04:34 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id AAA05472; Tue, 12 Dec 1995 00:03:44 -0500 Message-ID: <951211233058_51562464@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu, kgstar@most.fw.hac.com Subject: Re: Engineering Newsletter Date: Tue, 12 Dec 1995 00:03:44 -0500 Kelly re: Timothy Subject : Plasma mirror >> >>>> I don't think refocussing is necessary, the mirror itself can >> >>>> be just a flat mirror so the reflected beam is nothing >> >>>> different than the beam from Earth. >> >> >> >>>That would mean the catcher sail on the ship would be the same size as the >> >>>reflector mirror. That would mean it would get more push forward from the >> >>>direct beam from earth, than push back from the reflected beam from the >> >>>mirror. >> > >> >>Hmm, yes, but there seems to have a similar problem with >> >>the plasma mirror. >> > >> >Not really, Since the ring sail & catcher mirror are in the same place >> >(attached to the ship) the ring sail would be getting the same energy (no >> >energy drop due to r^2 losses.) >> >> But would the beam from Earth not strike the ring sail? >> If not, please could you make an (ASCII)drawing, because then I don't >> understand how where the ring-sail and catcher mirror and the plasma are >> located. Yes, the beam strikes the ring sail, and is reflected backward (Sol ward) and inward toward a small catcher mirror. The beam is then reflected forward from the catcher mirror to the plasma mirror. Net fore-aft thrust is nil until after it reflects off the plasma mirror. >> >> I don't use a ring-sail AND a catcher mirror, during deceleration, I have >> only one flat mirror directed to TC on the ship and a retro-mirror that is >> not coupled to the ship. A|----\ O-----------/ O Earth ----------- Beam from Earth \ / Retro-mirror ---- Beam from TC (Beam from Earth reflected by the retro-mirror) A| Asimov with a flat mirror >> >> This design makes the total mirror about 3 times bigger. >> >>The beam from Earth should be directed mainly on mirror B >> >> so that the beam to the Earth (or from TC) is reflected >> >>mainly from A. The final result is that there are two beams >> >> next to each other, one is going up the other is >> >>going down. >> >> >Whats the advantage? >> >> It overcomes the problem you mentioned: tracking. >> The only thing the Asimov has to do is move about 1000 kilometers to the >> left after it has uncoupled the retro-mirror. The result is that the mirror >> and the Asimov will move in the same direction during deceleration. You still haven't dealt with the problems of a drop mirror. - Given that the point of the exercise is that the mirror and ship will accelerate apart until they are moving apart at nearly light speed. They will be getting very far apart, and the "Retro-mirror" will need to aim to track the decelerating ship. By having the ships flat reflector mirror the size of the full power mirrors you eliminate the retro-mirror needs to focus, but not to keep aiming at the retreating ship. In trade you've added increased need for structural material, and added extra forward thrust from the earth beam on the back of the ship. (I don't by the ship running on a tiny beam that just fits in the sail. The ship will need to maneuver, and the transmitters couldn't hope to generate that much accuracy.) - The energy retuning to ship will drop off like a rock as the distance between ship and retro or drop mirror increases. Given that the mirror will not be that smooth (it will probably be rippling) the beam will be diverging badly after it reflects. - Need for active control systems on drop mirror. - Need for structural stiffening on drop mirror. ============================================================================== Kelly re: Timothy Subject : nanoAI >> >>We have ideas, the biggest problem is the enormous amounts >> >>of fuel that are needed. Lets say we use a >> >>take-all-fuel-with-you system. For matter&anti-matter fuel >> >> the ratio fuel:ship would be about 20:1 for small ships 1E4 >1E5 kg this >> >may be acceptable but for ships 1E8 or 1E9 kg >> >>its a completely different story. >> > >> >Your taking hundreds of tons of antimatter! That is a staggering amount to >> >manufacture, or even hold on to! >> >> My assumptions are that making anti-matter in 50 years will be about 50% >> efficient. Of course I can't be sure of this, but why wouldn't it? >> (Rethorical question) >> Besides this efficiency, I wonder why you are so blaffed by these numbers. >> These numbers are just the sum of the energy needed during 1 or 2 years of >> acceleration. >> If we build a maser beaming station, a similar amount of energy is needed. >> The only thing you do when transferring energy to anti-matter is making it a >> bit more permanent. It probably is the easiest way to store such amounts of >> energy. >> >> So the moral is, anti-matter is merely an amount of energy that is easier to >> keep in storage. Easier? The ship would still need to carry something like its own weight in matter anti-mater. A mass of thousands to millions of tons. Forward was hoping optimistically we'd be able to routinely generate and store milligrams to grams of antimatter. >> >> >People are mentally much more adaptable and reliable than any current >> >Nano/A.I. systems. >> >> You can't compare adaptability and reliable to CURRENT systems. That would >> be the same as to say that current engines would not work for our project >> and thus that it was not possible. True, but since no current A.I. system works very well, and no nano-tech systems work at all, I'd have a very hard time expecting them to be developed to that degree of reliability in 50 years. Its out there with the "we discover warp drive possibilities". Sooner or later we'll do them, or something like them; but they don't fit within LITs "no radical new tech" parameters >> From this I can conclude that I have a more optimistic view about nanotech >> and AI, then you do. >> Of course nanotech and AI are now in an early stage, but if 50 years ago, >> you had said what computers of today would be like, then they had laughed at >> you also. 50 years ago we had production computers. Only a handful, and their capacities were trivial be current standards; but thats farther than Nano/A.I. systems, and no current computer or automation system could attempt anything on the scale of what you are suggesting >> >>That is something completely different discussion: Why do we >> >>want to go there anyway. I was having a discussion with Nick >> >>Tosh about that, until his connection broke down. I can tell >> >>you, that I don't know why we want to go there so soon >> >>anyway. >> >>If you have an answer I'd like to know... >> > >> >As I remember the idea of LIT was to see if we could think of some way we >> >could build a starship in 2050 with probable technology of the day. Tau C >> >was selected as a target to focus the groups attention on. >> >> I know that, but I thought it was interesting to figure out why we want to >> go there. Is it just to have pissed on the ground there? Or is it because we >> want to colonize it? Or is it for scientific reasons? Or maybe all of them? >> All these things me be reasonable at first but, if you think a bit further, >> they make not much sense anymore... True. The LIT project assumed a big (blank check) push to go to Tau, but no reason or goal was given, and the group has never been able to agree on one. Thats a pretty big hole in the discussion, but since we also can't figure out how to get there in the first place its kind of a mute point. One thing I was considering was what we can do. My Explorer design could certainly be able to carry enough fusion fuel to decelerate from 1/10th C. Marshal Savage mention something like a 20 to 1 fuel to ship mass ration to do that. I'd like to check that, but for the moment will assume its true. Obviously trying to do that at 2/10ths C would take 20 squared (400) ship masses of fuel. So thats out, but at even those speeds drag is a serious factor. Savages book mentions that at near light speed the (one atom per cubic centimeter) inter-stellar Medium could cause up to 37 milligrams of drag pressure per square centimeter of frontal area. I'd like to work up the numbers for various interstellar densities and ship speeds; but it seems likely that some kind of magnetic or electrostatic, scoop or parachute could give us a big amount of breaking force. If we stay with a .1 to .2 C top speed ship we might be able to get a practical mission to some of the nearer stars. Not Tau C, but Alpha Centuri, Barnard's, Rigil Kent (Rigel kent A is a G2 yellow Main star at 4.4 LY, B is a K6 orange-main at 4.4). A .2 C ship could get there in a usable period of time. A version of my Explorer Fusion design could get there and back. If you have some reason of wanting to go there regularly. The first ship could assemble automated fuel launchers in the target systems. That would allow lighter ships to make the same run at higher speeds without carrying heavy fuel loads. (Assuming they trusted the fuel launcher at the receiving system to answer their launch command.) I suppose launching construction/survey flights might be practical (i.e someone might be willing to pay for them.) if they could be kept down to that length of time, and the public had an interests in the stars similar to the Apollo days. But what do we do there that would interest people that much? Science seems a pretty thin reason. Colonies can be built in this solar system just as well as another. Apollo was run for the international prestige (specifically vs the Soviets). I can't see anyone coming up to threaten a specific group that much by 2050; but even without that the project might attract enough enthusiasm among a major country to fund it. (My experience on International space projects makes me discount them out of hand.) So I guess what we want to do there is a question that we'd need to resolve. More specifically why we'ld feel we needed to do it then? If you willing to wait another half century. You could expect to have relyable equipment based on physics unknown to us now. (Matter conversion? Time space distortion? Such things have been seriously proposed.) Kelly From popserver Tue Dec 12 18:11:19 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1935" "Tue" "12" "December" "1995" "09:19:36" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "45" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id GAA16681 for ; Tue, 12 Dec 1995 06:25:27 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA16294; Tue, 12 Dec 95 09:22:04 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016212; Tue Dec 12 09:20:33 1995 Received: by most (4.1/SMI-4.1) id AA02033; Tue, 12 Dec 95 09:20:30 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002022; Tue Dec 12 09:19:39 1995 Received: from [151.168.158.72] by ss4.uiv (4.1/SMI-4.1) id AA01252; Tue, 12 Dec 95 09:19:35 EST X-Sender: kgstar@pophost.magec.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu, kgstar@most.magec.com Subject: Re: Engineering Newsletter Date: Tue, 12 Dec 1995 09:19:36 -0500 Ram mass? Ram Scoop collector 1000 km diameter scoop 200 tons. The speed of light is 300,000 kilometers per second Assuming your moving at 1/3rd the speed of light (100,000 kilometer per second, or 1E10 cm/sec) with a scoop area of 1000 km (pi*R^2=pi(50,000,000cm)^2 = 7.854E15 cm^2). You'd be scooping up the mass in 7.854 E25 cubic centimeters of space. A big question is the composition of interstellar space. A classic assumption is that there is nothing but about 1 atom of hydrogen in a cubic centimeter of space. More recently, people guess it might be less than .054 atoms per cubic centimeter or as many as 10. Even more recently than that (say the last few months) it has been proposed that there may be a lot of long-chain carbon molecules in space. Perhaps 60-200 atoms / molecules. These small, dark, heavy molecules might be the missing 90-99% of the mass of the galaxy (euphemistically called "dark matter"). So far, no one really knows. This is unfortunate, because the composition of the interstellar medium makes a hell of a difference in the design of a RAIR-based starship. Since we don't know one way or the other, let's assume one atom per cubic centimeter at a proton mass of 1.673 E-27 Kg. At 0.333c, using the above design figures, our 1000 km in diameter scoop, scoops up a ram flow of 131.4 grams per second. thats 473 kilos per hour 4.14 million kilos per year. Given a ship weighing hundreds of times that. This isn't going to slow us down much. Of course the mass of inter stellar medium is hotly debated. Some give numbers 100 times heavyer, but others think its much less. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.magec.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.magec.com/external.html) ---------------------------------------------------------------------- From popserver Thu Dec 14 18:07:49 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2216" "Wed" "13" "December" "1995" "19:18:32" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "44" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id QAA07839 for ; Wed, 13 Dec 1995 16:20:01 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id TAA24227; Wed, 13 Dec 1995 19:18:32 -0500 Message-ID: <951213191826_72201277@mail06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, david@interworld.com, MLEN3097@mercury.gc.peachnet.edu Subject: Re: Engineering Newsletter Date: Wed, 13 Dec 1995 19:18:32 -0500 We were talking about how much drag we might be able to get out of the interstellar medium. I dug some old numbers out of my LIT web page and tinkered with them. Note that my numbers were for 1.3rd light speed, so I didn't bother with relativity corrections. Kelly Starks ================================================== Ram Scoop collector 1000 km diameter scoop 200 tons. The speed of light is 300,000 kilometers per second Assuming your moving at 1/3rd the speed of light (100,000 kilometer per second, or 1E10 cm/sec) with a scoop area of 1000 km (pi*R^2=pi(50,000,000cm)^2 = 7.854E15 cm^2). You'd be scooping up the mass in 7.854 E25 cubic centimeters of space. A big question is the composition of interstellar space. A classic assumption is that there is nothing but about 1 atom of hydrogen in a cubic centimeter of space. More recently, people guess it might be less than .054 atoms per cubic centimeter or as many as 10. Even more recently than that (say the last few months) it has been proposed that there may be a lot of long-chain carbon molecules in space. Perhaps 60-200 atoms / molecules. These small, dark, heavy molecules might be the missing 90-99% of the mass of the galaxy (euphemistically called "dark matter"). So far, no one really knows. This is unfortunate, because the composition of the interstellar medium makes a hell of a difference in the design of a RAIR-based starship. Since we don't know one way or the other, let's assume one atom per cubic centimeter at a proton mass of 1.673 E-27 Kg. At 0.333c, using the above design figures, our 1000 km in diameter scoop, scoops up a ram flow of 131.4 grams per second. thats 473 kilos per hour 4.14 million kilos per year. (4,140 metric tons per year.) Given a ship weighing hundreds of times that. This isn't going to slow us down much. But if we want to assume lots of carbon molecules, the mass could jump up to the mass of the ship per year. But thats probably a bad assumption here near Sol. Seems this area of the galaxy is in a big bubble of space blasted nearly clean of debries by a recent supernova. So we may be living in one of the worst areas of the galaxy for a ramscoop, or ram breaked, starship. Kelly From popserver Thu Dec 14 19:13:04 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7390" "Thu" "14" "December" "1995" "20:09:36" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "142" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id LAA12543 for ; Thu, 14 Dec 1995 11:08:54 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA03098 (5.67b/IDA-1.5 for ); Thu, 14 Dec 1995 20:09:29 +0100 Message-Id: <199512141909.AA03098@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Thu, 14 Dec 1995 20:09:36 +0100 Timothy re: Kelly Subject : Plasma mirror >You still haven't dealt with the problems of a drop mirror. > - Given that the point of the exercise is that the mirror and ship will >accelerate apart until they are moving apart at nearly light speed. They >will be getting very far apart, and the "Retro-mirror" will need to aim to >track the decelerating ship. By having the ships flat reflector mirror the >size of the full power mirrors you eliminate the retro-mirror needs to focus, >but not to keep aiming at the retreating ship. "Very far" would be something like 2 ly: The mirror and the ship will be furthest apart when the Asimov has decelerated and is near TC. It takes approximately 8 years to decelerate the Asimov. The mirror never exceeds the speed of light and thus travels about 8 ly. It is released from the Asimov when 6 ly from TC. So after 8 years the Asimov has decelerated and is near TC. The mirror is then thus 2 ly further than TC and the Asimov. So the extra distance is not so much as you would think. But of course still the problem of aiming is there. I've no solution other than some gyro-system. But what I don't understand is what is the difference between aiming the beam that comes from Earth and the beam that comes from the retro-mirror? The only thing the retro-mirror has to do is not turn, so it does not have to aim but just not have to turn. Do you know what the difference is between aiming the beam from Earth and aiming from the retro-mirror? > In trade you've added increased need for structural material, and added >extra forward thrust from the earth beam on the back of the ship. (I don't >by the ship running on a tiny beam that just fits in the sail. The ship will >need to maneuver, and the transmitters couldn't hope to generate that much >accuracy.) Increased structural material, indeed, but that does not matter, because the heavier the retro-mirror the less the doppler shifts. I don't buy you saying that the beam may be much bigger than the mirror. If you throw away most of the energy anyway, just by using a mirror that is too small, than you could also use an engine that has a worthless effeciency. Furthermore, I don't see why the ship wants to maneuver so much. It always has to stay in the beam for most of the time. If indeed the accuracy of the transmitters is that worse, my advice is to no use the beaming idea. >- The energy retuning to ship will drop off like a rock as the distance >between ship and retro or drop mirror increases. Given that the mirror will >not be that smooth (it will probably be rippling) the beam will be diverging >badly after it reflects. How well do you think that a plasma will reflect? Probably my almost flat mirror would do a much better job. I really don't agree using a beam for about 10% or less. It should be at least 50% otherwise, other systems may be more effecient. ============================================================================== Timothy re: Kelly Subject : nanoAI >Easier? The ship would still need to carry something like its own weight in >matter anti-mater. A mass of thousands to millions of tons. Forward was >hoping optimistically we'd be able to routinely generate and store milligrams >to grams of antimatter. Once again, anti-matter is just energy. The only thing that is important is the efficiency. How well can we transfer energy to matter? My assumtion is that this efficiency should be about 50% in 2040. If this isn't reasonable, than indeed it is a bad choice. My guess is that Forward also has no idea of generating 10E18 Watts of power or a total amount of 1E26 Joules of energy! And this is approx. the energy and power needed for most designs. >True, but since no current A.I. system works very well, and no nano-tech >systems work at all, I'd have a very hard time expecting them to be developed >to that degree of reliability in 50 years. Its out there with the "we >discover warp drive possibilities". Sooner or later we'll do them, or >something like them; but they don't fit within LITs "no radical new tech" >parameters Have you seen any (well) working plasma-mirrors yet? I really think that nanoAI is not that exotic as you think. The AI systems of today are capable of learning to read out loud (but not to understand). One of the things that keeps them from doing more difficult tasks is the amount of "neurons" (currently about 1E8 or so). This amount depends both on fast and vast memories. There has just been designed a chip with a build in neural-network for all kinds of purposes. About nano-tech I know a bit less, but certainly there are significant breaktroughs. And nano-tech has the same potential as computers had. Once there is a beginning, growth will be exponentially. >One thing I was considering was what we can do. My Explorer design could >certainly be able to carry enough fusion fuel to decelerate from 1/10th C. > Marshal Savage mention something like a 20 to 1 fuel to ship mass ration to >do that. I'd like to check that, but for the moment will assume its true. I checked it and its even better. For acceleration and deceleration a ratio of 1:10 when the exhaust speed is about 0.088 c (Quite critical value) For 0.2c the ratio becomes 1:100 and for 0.3c it is about 1:1100 > Obviously trying to do that at 2/10ths C would take 20 squared (400) ship >masses of fuel. So thats out, but at even those speeds drag is a serious >factor. Savages book mentions that at near light speed the (one atom per >cubic centimeter) inter-stellar Medium could cause up to 37 milligrams of >drag pressure per square centimeter of frontal area. I'd like to work up the >numbers for various interstellar densities and ship speeds; but it seems >likely that some kind of magnetic or electrostatic, scoop or parachute could >give us a big amount of breaking force. 3E10 cm/s * 1 atom/cm^3 = 3E10 atoms/cm^2 3E10 atoms/cm^2 * 1.67E-27 kg/atom = 5E-17 kg/cm^2 As you can see that number of Savage is completely wrong. (I did this calculation a week ago also!) >If we stay with a .1 to .2 C top speed ship we might be able to get a >practical mission to some of the nearer stars. Not Tau C, but Alpha Centuri, >Barnard's, Rigil Kent (Rigel kent A is a G2 yellow Main star at 4.4 LY, B is >a K6 orange-main at 4.4). A .2 C ship could get there in a usable period of >time. A version of my Explorer Fusion design could get there and back. If >you have some reason of wanting to go there regularly. The first ship could >assemble automated fuel launchers in the target systems. That would allow >lighter ships to make the same run at higher speeds without carrying heavy >fuel loads. (Assuming they trusted the fuel launcher at the receiving system >to answer their launch command.) 4.4/0.2=22 years for a complete one way trip. Not better than we are currently planning for TC. >So I guess what we want to do there is a question that we'd need to resolve. > More specifically why we'ld feel we needed to do it then? If you willing to >wait another half century. You could expect to have relyable equipment based >on physics unknown to us now. (Matter conversion? Time space distortion? > Such things have been seriously proposed.) This was what I meant, and I haven't got a clue what the answer could be. But as you said this has nothing to do with the initial goal of SD. Timothy From popserver Sat Dec 16 18:03:12 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["16120" "Fri" "15" "December" "1995" "23:08:09" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "347" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id UAA21343 for ; Fri, 15 Dec 1995 20:09:19 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id XAA24326; Fri, 15 Dec 1995 23:08:09 -0500 Message-ID: <951215230809_91593264@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl cc: Bogart1594@aol.com, David@interworld.com, lunar@sunsite.unc.edu Subject: Re: Engineering Newsletter Date: Fri, 15 Dec 1995 23:08:09 -0500 >> Timothy re: Kelly >> Subject : Plasma mirror >> >> >You still haven't dealt with the problems of a drop mirror. >> > - Given that the point of the exercise is that the mirror and ship will >> >accelerate apart until they are moving apart at nearly light speed. They >> >will be getting very far apart, and the "Retro-mirror" will need to aim to >> >track the decelerating ship. By having the ships flat reflector mirror the >> >size of the full power mirrors you eliminate the retro-mirror needs to focus, >> >but not to keep aiming at the retreating ship. >> >> "Very far" would be something like 2 ly: >> The mirror and the ship will be furthest apart when the Asimov has >> decelerated and is near TC. >> It takes approximately 8 years to decelerate the Asimov. The mirror never >> exceeds the speed of light and thus travels about 8 ly. It is released from >> the Asimov when 6 ly from TC. So after 8 years the Asimov has decelerated >> and is near TC. The mirror is then thus 2 ly further than TC and the Asimov. >> >> So the extra distance is not so much as you would think. But of course still >> the problem of aiming is there. I've no solution other than some >> gyro-system. But what I don't understand is what is the difference between >> aiming the beam that comes from Earth and the beam that comes from the >> retro-mirror? The only thing the retro-mirror has to do is not turn, so it >> does not have to aim but just not have to turn. >> Do you know what the difference is between aiming the beam from Earth and >> aiming from the retro-mirror? Yes, the beam from earth can be maintained by a massive infrastructure of people carefully tuning it to keep it in the track to T.C. They also can make up for accuracy problems by making a bigger beam. Transmitting a hundred or a thousand times as much power as needed to compensate for all the waste that misses the ship. Thats not very efficient (but thats not a problem), and will cost a lot more (which might be a problem); but it could still work. (Actually you would need to do that anyway in order to give the ship some room to maneuver around in the beam.) The retro-sail on the other hand is a weak flimsy structure of huge dimensions, which has to keep a pinpoint aim of nearly all its reflected energy at a distance of light years. A neat trick given its basically a huge unsupported sheet of foil being blown along by the beam. Oh, and it would have to keep a pinpoint aim on a moving object up to two light years away. So it would be 2 years out of date in its understanding of where the ship was, and was going. And no you can't just not turn. First, given the load on it from the beam, its certain it will being twisted by beam asysmetries. Secound the ship can't be in direct line between the mirror and the beam, so their will be a changing angular offset. >> > In trade you've added increased need for structural material, and added >> >extra forward thrust from the earth beam on the back of the ship. (I don't >> >by the ship running on a tiny beam that just fits in the sail. The ship will >> >need to maneuver, and the transmitters couldn't hope to generate that much >> >accuracy.) >> >> Increased structural material, indeed, but that does not matter, because the >> heavier the retro-mirror the less the Doppler shifts. Also the more power you need to drive it and the ship up to speed, and more power needs for its maneuvering systems to turn it to keep aimed at the ship. Besides you couldn't possibly add enough mass to a structure hundreds to thousands of kilometers across to keep it optically flat! >> I don't buy you saying that the beam may be much bigger than the mirror. If >> you throw away most of the energy anyway, just by using a mirror that is too >> small, than you could also use an engine that has a worthless efficiency. The beam must be much bigger then the sail, and wasting energy isn't a critical problem. The purpose of the beam is to drive the ship. As long as enough of the beam gets to the ship to do that, the system can work. (I.E. the it can get the ship where it wants to go.) Efficiency is a cost concern, but would not effect the success of the project. After all you don't have to move the transmitters. The ships engines however have to be pretty efficient in order to get the job done (and not melt the ship in the process). We're nowhere near being able to design a starship that can "affordably" get back and forth to Tau Ceti. >> Furthermore, I don't see why the ship wants to maneuver so much. It always >> has to stay in the beam for most of the time. >> If indeed the accuracy of the transmitters is that worse, my advice is to no >> use the beaming idea. I expect it will need to maneuver around any interstellar rocks or other such junk. (Hitting a 4 kilometer comet at relativistic speeds is hard on the hull!!) One advantage of the beamed concept is that the unreflected energy acts as a radar searchlight to show whats ahead of the ship. >> >- The energy returning to the ship will drop off like a rock as the distance >> >between ship and retro or drop mirror increases. Given that the mirror will >> >not be that smooth (it will probably be rippling) the beam will be diverging >> >badly after it reflects. >> >> How well do you think that a plasma will reflect? Probably my almost flat >> mirror would do a much better job. The plasma reflector will be right next to the ship (surrounded by it actually). So couldn't possibly miss the ship, and doesn't need to keep a tightly aimed beam. The retro-mirror on the other hand will be up to 2 light years from the ship, and need to reflect a perfectly beam that converges inward toward a smaller drive mirror on the ship. The later is a much harder problem. >> I really don't agree using a beam for about 10% or less. It should be at >> least 50% otherwise, other systems may be more efficient. Do you mean you don't want to use a beam system thats that inefficient? Efficiency in catching the beam is a luxury we can worry about later. Right now we're just trying to devise a system that could possibly get us there at all! The choice isn't going wastefully vs going efficiency, but going wastefully or not going at all! ============================================================================== >> >> Timothy re: Kelly >> Subject : nanoAI >> >> >Easier? The ship would still need to carry something like its own weight in >> >matter anti-mater. A mass of thousands to millions of tons. Forward was >> >hoping optimistically we'd be able to routinely generate and store milligrams >> >to grams of antimatter. >> >> Once again, anti-matter is just energy. The only thing that is important is >> the efficiency. How well can we transfer energy to matter? My assumption is >> that this efficiency should be about 50% in 2040. If this isn't reasonable, >> than indeed it is a bad choice. >> My guess is that Forward also has no idea of generating 10E18 Watts of power >> or a total amount of 1E26 Joules of energy! >> And this is approx. the energy and power needed for most designs. I have no idea how you plan to convert energy directly to anti-matter. Certainly thats not how we make it now. Even if we could generate the anti matter, how would you store and move amounts on that scale safely? And of course how do you refuel for the return trip? Your probably right about the E18+ power being a 'show stopper' thou. I can't think of any reasonable scenario that would have us able to put that kind of power on line, in space, in about 50 years. >> >True, but since no current A.I. system works very well, and no nano-tech >> >systems work at all, I'd have a very hard time expecting them to be developed >> >to that degree of reliability in 50 years. Its out there with the "we >> >discover warp drive possibilities". Sooner or later we'll do them, or >> >something like them; but they don't fit within LITs "no radical new tech" >> >parameters >> >> Have you seen any (well) working plasma-mirrors yet? I really think >> that nanoAI is not that exotic as you think. >> The AI systems of today are capable of learning to read out loud (but not to >> understand). One of the things that keeps them from doing more difficult >> tasks is the amount of "neurons" (currently about 1E8 or so). This amount >> depends both on fast and vast memories. There has just been designed a chip >> with a build in neural-network for all kinds of purposes. >> About nano-tech I know a bit less, but certainly there are significant >> breakthroughs. And nano-tech has the same potential as computers had. Once >> there is a beginning, growth will be exponentially. Your definitely more optimistic about nano and A.I. than I. We after all can and do reflect radio and microwave off ionized gas all the time. We have no Nano systems, and are making painfully slow progress in A.I. (A.I. first learned to read aloud over ten years ago.) So I do think they are unlikely to be mature enough in 50 years to help us much. Actually, even if they did work, they wouldn't solve any critical problems for us. Just improve effecency and affordability. >> >One thing I was considering was what we can do. My Explorer design could >> >certainly be able to carry enough fusion fuel to decelerate from 1/10th C. >> > Marshal Savage mention something like a 20 to 1 fuel to ship mass ration to >> >do that. I'd like to check that, but for the moment will assume its true. >> >> I checked it and its even better. For acceleration and deceleration a ratio >> of 1:10 when the exhaust speed is about 0.088 c (Quite critical value) >> >> For 0.2c the ratio becomes 1:100 and for 0.3c it is about 1:1100 Hum... I just ran some numbers through the LIT Delta V program using the specific impulse of Bussards Fusion engines. I got about the same numbers at ..3c but I though I got slightly better numbers at .2c. But I don't have the numbers with me. Then again, I'm not even sure the LIT program nows to add the need to accelerate the fuel mass with the ship (I certainly hope it does, I'll have to test it.) >> > Obviously trying to do that at 2/10ths C would take 20 squared (400) ship >> >masses of fuel. So thats out, but at even those speeds drag is a serious >> >factor. Savages book mentions that at near light speed the (one atom per >> >cubic centimeter) inter-stellar Medium could cause up to 37 milligrams of >> >drag pressure per square centimeter of frontal area. I'd like to work up the >> >numbers for various interstellar densities and ship speeds; but it seems >> >likely that some kind of magnetic or electrostatic, scoop or parachute could >> >give us a big amount of breaking force. >> >> 3E10 cm/s * 1 atom/cm^3 = 3E10 atoms/cm^2 >> 3E10 atoms/cm^2 * 1.67E-27 kg/atom = 5E-17 kg/cm^2 >> >> As you can see that number of Savage is completely wrong. (I did this >> calculation a week ago also!) Yeah, I dug up some numbers from my old web page (see above) that showed he was off the wall too. (Well at relativistic speeds time dilation might help his numbers) Looks like no magnetic drag chutes. >> >If we stay with a .1 to .2 C top speed ship we might be able to get a >> >practical mission to some of the nearer stars. Not Tau C, but Alpha Centauri, >> >Barnard's, Rigil Kent (Rigel kent A is a G2 yellow Main star at 4.4 LY, B is >> >a K6 orange-main at 4.4). A .2 C ship could get there in a usable period of >> >time. A version of my Explorer Fusion design could get there and back. If >> >you have some reason of wanting to go there regularly. The first ship could >> >assemble automated fuel launchers in the target systems. That would allow >> >lighter ships to make the same run at higher speeds without carrying heavy >> >fuel loads. (Assuming they trusted the fuel launcher at the receiving system >> >to answer their launch command.) >> >> 4.4/0.2=22 years for a complete one way trip. Not better than we are >> currently planning for TC. But, it would require far simpler systems, and a fraction of the power. A comparatively simple fusion powered ship with fuel launchers in sol could make a round trip. If it builds a big fuel launcher in the target system it could even cut the return trip time down. Like I said above, I ran some numbers off using the delta-v program on the LIT site, and got a 60 to 1 fuel to ship mass ration for a .2c Delta v, using the Bussard fusion drive motors. Thats not an impossible number (bad, but not impossible). So I think such a ship could be built by 2050. So we could get to the nearer stars. At .2c we could get to the 4.5 to 5ish ly stars in 22-25 years. Which should be quick enough to be do able (thou its pushing it!), thou the crew will probably die durring the 25 year return flight. On the return flight the ship would load up with enough fuel to boost it back up to speed. It couldn't possibly carry enough fuel to accelerate, and decelerate! So it will have to use fuel launched by the Sol fuel launchers to power its deceleration boost. (Better home the folks back home still like you! ;) ) But then again, if we bring enough gear to build a fuel launcher at the target star system. The ship could boost for home with little or no fuel on board. Its speed wouldn't be limited to the maximum speed it can get out of the stored fuel its carring, or that it can carry the deceleration fuel to stop from. Accelerating with near empty fuel tanks the ship will weight a tiny fraction of the max weight its engines and structure were designed for. The crew could keep the extra for redundancy (the ship will be getting old by then), or they could strip some or all of the systems off to lighten the ship even further. Allowing the crew to boost at higher G's in the acceleration track, order to get to higher speeds. Remember, the limitation on accelerating in a pre-launched fuel stream. Is how far out you can get before the fuel gets so spread out that you can't scoop up enough fuel to run the engines. I.E. how accuratly can you launcher put the fuel? A striped down ship could not only accelerate faster, getting to higher speeds within a given distence from the fuel launcher. It could also get by on less fuel, allowing it to still keep up thrust farther out from the fuel launcher then its heavyer brother. If the folks back home really like you. They will have upgraded their fuel launcher in your absence. Allowing you to get a usable fuel density at far farther out from Sol. >> >So I guess what we want to do there is a question that we'd need to resolve. >> > More specifically why we'd feel we needed to do it then? If you willing to >> >wait another half century. You could expect to have reliable equipment based >> >on physics unknown to us now. (Matter conversion? Time space distortion? >> > Such things have been seriously proposed.) >> >> This was what I meant, and I haven't got a clue what the answer could be. >> But as you said this has nothing to do with the initial goal of SD. Yeah, but it seems to be an issue we need to resolve. As is, a .2 C ship with the ability to go faster with fuel launchers at both ends, seems reasonable by 2050. A near light speed ship seems out of the question. The microwave sail idea requires completely absurd amounts of power, and we can't seem to find a practical way to stop the ship. So until we change the physics we have to work with (or learn a much better way to manufacture and store anti-matter) we are limited to slower, shorter range fights. But flights that would be technically (and financially) far less chalenging. Does anyone disagree? Kelly P.S. Where is David? I keep geting undeliverable mail mesages when I ship to his office. Has anyone heard from him lately? P.P.S. Opps, I forgot to look up the thrust to weight ratio of the Bussard plasma engines. If their too low, the ship wouldn't be able to carry enough fuel. From popserver Sat Dec 16 20:38:55 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["12175" "Sat" "16" "December" "1995" "21:36:56" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "243" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id MAA16981 for ; Sat, 16 Dec 1995 12:36:03 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA21246 (5.67b/IDA-1.5 for ); Sat, 16 Dec 1995 21:36:50 +0100 Message-Id: <199512162036.AA21246@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 16 Dec 1995 21:36:56 +0100 Timothy re: Kelly Subject : Plasma mirror >Yes, the beam from earth can be maintained by a massive infrastructure of >people carefully tuning it to keep it in the track to T.C. They also can >make up for accuracy problems by making a bigger beam. Transmitting a >hundred or a thousand times as much power as needed to compensate for all the >waste that misses the ship. Thats not very efficient (but thats not a >problem), and will cost a lot more (which might be a problem); but it could >still work. (Actually you would need to do that anyway in order to give the >ship some room to maneuver around in the beam.) > >The retro-sail on the other hand is a weak flimsy structure of huge >dimensions, which has to keep a pinpoint aim of nearly all its reflected >energy at a distance of light years. A neat trick given its basically a huge >unsupported sheet of foil being blown along by the beam. Oh, and it would >have to keep a pinpoint aim on a moving object up to two light years away. > So it would be 2 years out of date in its understanding of where the ship >was, and was going. OK, I see the difference. But what I want to make clear is that it does not have to know where the ship is. (see next comment) >And no you can't just not turn. First, given the load on it from the beam, >its certain it will being twisted by beam asysmetries. Secound the ship >can't be in direct line between the mirror and the beam, so their will be a >changing angular offset. What I meant with no turning, was that it just had to reflect the beam STRAIGHT back. To do that is has a very precise orientation: the incoming beam. The mirror does not have to track a moving object, that is the task of the Earth beaming station. If Earth beams it to the Asimov, then it also aims to the mirror. because the Asimov and the retro-mirror are always lined up. >Also the more power you need to drive it and the ship up to speed, and more >power needs for its maneuvering systems to turn it to keep aimed at the ship. > Besides you couldn't possibly add enough mass to a structure hundreds to >thousands of kilometers across to keep it optically flat! Both are true, but since you are talking about losses of 99% or 99.9% (due to beam that is bigger than the mirror) I guess that energy to maneuver is just a minor extra. Also the heavier the mirror, the less it is turned by the beam, so it takes less to turn it back. (So the total energy stays about the same) >The beam must be much bigger then the sail, and wasting energy isn't a >critical problem. The purpose of the beam is to drive the ship. As long as >enough of the beam gets to the ship to do that, the system can work. (I.E. >the it can get the ship where it wants to go.) Efficiency is a cost concern, >but would not effect the success of the project. After all you don't have to >move the transmitters. The ships engines however have to be pretty efficient >in order to get the job done (and not melt the ship in the process). We're >nowhere near being able to design a starship that can "affordably" get back >and forth to Tau Ceti. Efficiency is not only a cost concern, if we had 100 to 1000 times more energy available, then certain things would be a lot easier. >I expect it will need to maneuver around any interstellar rocks or other such >junk. (Hitting a 4 kilometer comet at relativistic speeds is hard on the >hull!!) One advantage of the beamed concept is that the unreflected energy >acts as a radar searchlight to show whats ahead of the ship. I think that the beam from Earth has completely ionized and blown away these rocks before the Asimov gets into sight. Also there won't be that many big rocks in interstellar space. (If they were, they would certainly make a good braking force) >The plasma reflector will be right next to the ship (surrounded by it >actually). So couldn't possibly miss the ship, and doesn't need to keep a >tightly aimed beam. The retro-mirror on the other hand will be up to 2 light >years from the ship, and need to reflect a perfectly beam that converges >inward toward a smaller drive mirror on the ship. The later is a much harder >problem. Both the retro-mirror and the mirror on the Asimov are about the same size! You say the plasma surrounds the ship, I thought they were at the TC side of the ship. Does design looks like this: ) ------------) /) (--------| Plasma (--------| Plasma \) ------------) ) ( are the small mirror at the Earth side of the Asimov ) are the big mirror at TC side of the Asimov -- / \ Light rays As soon as the photons hit the plasma how are they reflected? >Do you mean you don't want to use a beam system thats that inefficient? >Efficiency in catching the beam is a luxury we can worry about later. Indeed, that's what I'm saying. If a system is only 10% or even 0.1% efficient, then for example a fusion system that uses a 1:1000 ship:fuel ratio as well. >Right >now we're just trying to devise a system that could possibly get us there at >all! The choice isn't going wastefully vs going efficiency, but going >wastefully or not going at all! I do not agree, as I said before, the anti-matter engine WILL work. Only you do think that it is very difficult to make anti-matter if you have the energy available. I, on the other hand don't see a reason why this should be so extremely difficult in 50 years. (And if efficiency isn't that important this will certainly be an option) My calculations tell me that to reach 0.9c one needs approximately: 1 spoon of spacevessel 1 spoon of anti-matter 4 spoons of normal matter ============================================================================== Timothy re: Kelly Subject : nanoAI >I have no idea how you plan to convert energy directly to anti-matter. > Certainly thats not how we make it now. Even if we could generate the anti >matter, how would you store and move amounts on that scale safely? And of >course how do you refuel for the return trip? Today we use the brute force method of collision. The particles that are created during that collision are not used and the energy of them is thrown away after detecting them. (nothing gets much overheated since we are talking about only a few particles) The biggest losses are due to the cooling of the (super-conducting) magnets. If such a collider is build in space or if room-temp. supercoliders are discovered these big losses may come down. Also the collision should be made more efficient in the way that some particles like neutrons and protons are created more often than other particles. I think this could be done by using the exact right collision energies. Another possibility could be to create an energy field (eg. a box with a lot of photons) Then more (virtual) particles will form that may be extracted. This method is never used because it is not so easy to create such high energy fields, but I think it should work. How to store the anti-matter? Just like normal matter, create anti-atoms and anti-solids. Finally charge it and suspend it in electro/magnetic bottles. OK, it sounds easy, but it seems to be possible. How to refuel? First of all, I'm not so certain that it will return. You would be 65 when you're back on Earth while all you worked and lived for is on TC. Just to come back and play the hero doesn't seem that much fun. But if you really want, than you have to build a refueling station at TC. Too difficult? All methods need to build some kind of beaming or fuel station at TC and all are probably difficult to realize. >Your probably right about the E18+ power being a 'show stopper' thou. I can't >think of any reasonable scenario that would have us able to put that kind of >power on line, in space, in about 50 years. I think that we have to assume that this minimum is possible, otherwise no system is possible unless we "invent" anti-gravity, or if we use a ship that has much less mass (which is almost impossible). So it would be better if one the rules of the SD "discussion" was that a minimum (unknown?) power source of 1E18 watt is available in 2040. >Your definitely more optimistic about nano and A.I. than I. We after all can >and do reflect radio and microwave off ionized gas all the time. We have no >Nano systems, and are making painfully slow progress in A.I. (A.I. first >learned to read aloud over ten years ago.) So I do think they are unlikely >to be mature enough in 50 years to help us much. We indeed do reflect radio-waves, but we do that always at a non-perpendicular angle. I'm not sure but, I think it works worse for right angles. >Actually, even if they did work, they wouldn't solve any critical problems >for us. Just improve effecency and affordability. Increasing efficiency or affordability make any design more probable and feasable. If for example the space shuttle had AI and nanotech. it would probably much more saver, reliable and cheaper. If one makes such a big ship, a lot of things may go wrong and endanger the trip. The more complex the ship, the more probable that the trip isn't completed. NanoAI will decrease that probability significantly. >Hum... I just ran some numbers through the LIT Delta V program using the >specific impulse of Bussards Fusion engines. I got about the same numbers at >.3c but I though I got slightly better numbers at .2c. But I don't have the >numbers with me. Then again, I'm not even sure the LIT program nows to add >the need to accelerate the fuel mass with the ship (I certainly hope it does, >I'll have to test it.) I've made a derivation and a Pascal program that can do such calculations. It's on the WWW at URL: http://www.cpedu.rug.nl/~N0642983/calc.txt >Like I said above, I ran some numbers off using the delta-v program on the >LIT site, and got a 60 to 1 fuel to ship mass ration for a .2c Delta v, >using the Bussard fusion drive motors. Thats not an impossible number (bad, >but not impossible). So I think such a ship could be built by 2050. So we >could get to the nearer stars. At .2c we could get to the 4.5 to 5ish ly >stars in 22-25 years. Which should be quick enough to be do able (thou its >pushing it!), thou the crew will probably die durring the 25 year return >flight. My ratios where for acceleration AND deceleration together. Nearer goals would indeed make a better chance of succeeding, also it would be a cheaper way to "test" interstellar space-trips. The disadvantage is of course that the number of stars is much smaller and so are the chances of finding lifeforms or habitable planets. >Remember, the limitation on accelerating in a pre-launched fuel stream. Is >how far out you can get before the fuel gets so spread out that you can't >scoop up enough fuel to run the engines. I.E. how accuratly can you launcher >put the fuel? A striped down ship could not only accelerate faster, getting >to higher speeds within a given distence from the fuel launcher. It could >also get by on less fuel, allowing it to still keep up thrust farther out >from the fuel launcher then its heavyer brother. If the folks back home >really like you. They will have upgraded their fuel launcher in your >absence. Allowing you to get a usable fuel density at far farther out from >Sol. I've done some calculations, these show there is not that much profit (in energy) when one compares prelaunching with take-all-with-you (from now on TAWY). >So until we change the physics we have to work with (or learn a much better >way to manufacture and store anti-matter) we are limited to slower, shorter >range fights. But flights that would be technically (and financially) far >less chalenging. Does anyone disagree? Indeed, even with anti-matter there will be a limit, it will be something like 100 ly. But what a world would we create: It isn't possible to ask something and receive an answer within a lifetime. Even 4 ly is a big barrier. What happens if one creates a world that far away from Earth. It is in fact a isolated world. There won't be interactive communication. All information streams will be one way (from boths sides). Timothy From popserver Sun Dec 17 18:07:23 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2417" "Sun" "17" "December" "1995" "10:07:58" "-0500" "David Levine" "David@interworld.com" nil "48" "RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id HAA07789 for ; Sun, 17 Dec 1995 07:05:03 -0800 (PST) Received: by www with Microsoft Mail id <01BACC67.8D248AB0@www>; Sun, 17 Dec 1995 10:08:02 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BACC67.8D3CF4B0" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: Engineering Newsletter Date: Sun, 17 Dec 1995 10:07:58 -0500 ------ =_NextPart_000_01BACC67.8D3CF4B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Um, gang, sorry about the confusion. Our T1 has been down for over a week. Ugh. Anyway, I'm back on the air. It's going to take me a while to get back to speed, but at least mail to me won't bounce anymore. Thanks for understanding. David -- David Levine - Senior Applications Programmer - InterWorld http://www.interworld.com/staff/david/ "He tried to kill me with a forklift..." -------------------------------------------------------------------------- ------ =_NextPart_000_01BACC67.8D3CF4B0 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IgMPAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAARAAoA BwA6AAAAOgEBCYABACEAAABERDk1REQxQUY3MzdDRjExQUMwNzAwODA1RjE0QTJGMAA+BwEggAMA DgAAAMsHDAARAAoACAACAAAAAwEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAGwAAAFJFOiBFbmdpbmVlcmluZyBOZXdzbGV0dGVyAKkJAQ2ABAACAAAAAgACAAEDkAYA9AMA ABIAAAALACMAAAAAAAsAKQAAAAAAAwAmAAAAAAADADYAAAAAAB4AcAABAAAAFwAAAEVuZ2luZWVy aW5nIE5ld3NsZXR0ZXIAAAIBcQABAAAAGwAAAAG6y/KFp1DRaQY34RHPrAYAgF8UovAAJ47j8gAD AAYQw5K5cgMABxB4AQAAHgAIEAEAAABlAAAAVU0sR0FORyxTT1JSWUFCT1VUVEhFQ09ORlVTSU9O T1VSVDFIQVNCRUVORE9XTkZPUk9WRVJBV0VFS1VHSEFOWVdBWSxJTUJBQ0tPTlRIRUFJUklUU0dP SU5HVE9UQUtFTUVBVwAAAAADABAQAAAAAAMAERAAAAAAAgEJEAEAAABQAgAATAIAAMgDAABMWkZ1 tjzfav8ACgEPAhUCqAXrAoMAUALyCQIAY2gKwHNldDI3BgAGwwKDMgPFAgBwckJxEeJzdGVtAoMz twLkBxMCgzQSzBTINREMtjEPzwIANgPGFMV9CoCLCM8J2Tsa+TEyOAojxxzRHBoKFDI1NQKACoGD DbELYG5nMTAzFFAXCwoUUQvyYxKgIFVtWCwgZx9hIXBzBbByHHkgAaAIYAVAdGhlYiAFoG5mdQCQ AiAuyCAgTwhwIFQX4BGAhQQgYgnhIGRvdwOgZQIQcgqFb3YEkCJAIIp3CeBrI4FVZ2gjgUBBbnl3 YXkhcEnsJ20kUADQayWQA6AiskULcHIjgUl0JwQgZypvC4BnIqBvIqBha+5lCoUHgCXiaAMQItAp cU5nEcAnlClxc3AJ4GT1IXBiIoFhBUAq0CQwBUCvAMADESlxKlF3AiAnK1F5CGBuYynWAHAGwAWw ZZYuCoUKhVQRgG5rBCC9JQEgLmAEgRPAAHBkKTFBL41EYXZpZAqLbLhpMzYN8CA8E1BvE9DeYwVA Co8LkRViMRkgIRAnAFAAoDVGLS0yeiBM6mUzAG4i0C0GUQMABbHkQXALUGljLKAjUQQg5lADYAnA YW0HgAXAObBWSQIwBJBXBbBsMyZoQQJAcDovL3c9YC4vC4A8AS3gPFEuBaBtL1MxcQ3QL2Qy8i81 xSLeSCrhCIE5IClxawMQAyDdLbJpIrAl4SUBazQAAYD6LkIAIjXFOFBCz0PfRO/fRf9GQgtGFvE3 MDc1PhohAgBJcEAAOQCw82Rzkcy6AQIBRwABAAAANAAAAGM9VVM7YT0gO3A9SW50ZXJXb3JsZDts PVByaXZhdGUgTURCLTk1MTIxNzE1MDc1OVotMQBAAAcwEHVjc5HMugFAAAgwoJ4UdpHMugEeAD0A AQAAAAUAAABSRTogAAAAAAIBFDQBAAAAEAAAAFSUocApfxAbpYcIACsqJRcXFg== ------ =_NextPart_000_01BACC67.8D3CF4B0-- From popserver Mon Dec 18 18:02:37 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11190" "Sun" "17" "December" "1995" "22:45:54" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "267" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id TAA05766 for ; Sun, 17 Dec 1995 19:46:32 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id WAA09592; Sun, 17 Dec 1995 22:45:54 -0500 Message-ID: <951217224552_57060897@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sun, 17 Dec 1995 22:45:54 -0500 > > Timothy re: Kelly > Subject : Plasma mirror > What I meant with no turning, was that it just had to reflect the beam > STRAIGHT back. To do that is has a very precise orientation: the incoming > beam. The mirror does not have to track a moving object, that is the task of > the Earth beaming station. If Earth beams it to the Asimov, then it also > aims to the mirror. because the Asimov and the retro-mirror are always lined up. That wouldn't work, but eiather way. Straight back is still a direction to aim at, and it couldn't do it. --- snip --- > >The beam must be much bigger then the sail, and wasting energy isn't a > >critical problem. The purpose of the beam is to drive the ship. As long as > >enough of the beam gets to the ship to do that, the system can work. (I.E. > >the it can get the ship where it wants to go.) Efficiency is a cost concern, > >but would not effect the success of the project. After all you don't have to > >move the transmitters. The ships engines however have to be pretty efficient > >in order to get the job done (and not melt the ship in the process). We're > >nowhere near being able to design a starship that can "affordably" get back > >and forth to Tau Ceti. > > Efficiency is not only a cost concern, if we had 100 to 1000 times more > energy available, then certain things would be a lot easier. > > >I expect it will need to maneuver around any interstellar rocks or other such > >junk. (Hitting a 4 kilometer comet at relativistic speeds is hard on the > >hull!!) One advantage of the beamed concept is that the unreflected energy > >acts as a radar searchlight to show whats ahead of the ship. > > I think that the beam from Earth has completely ionized and blown away these > rocks before the Asimov gets into sight. Also there won't be that many big > rocks in interstellar space. (If they were, they would certainly make a good > braking force) We have no real idea whats in interstellar space, but is fair to expect a few comets, asteroids ect; and I don't think we can plan on everything in our way getting neatly blown out of the way. > >The plasma reflector will be right next to the ship (surrounded by it > >actually). So couldn't possibly miss the ship, and doesn't need to keep a > >tightly aimed beam. The retro-mirror on the other hand will be up to 2 light > >years from the ship, and need to reflect a perfectly beam that converges > >inward toward a smaller drive mirror on the ship. The later is a much harder > >problem. > > Both the retro-mirror and the mirror on the Asimov are about the same size! NO! A retro reflecter mirror wil not work unless the retro-mirror is much bigger. -If its the same size and the retro mirror is straight in frount of the ship. It will be in the shaddow of the ships drag mirror. So it won't 'see' any of the beam to reflect. - Even if its not in the line of sight. Being the same size as the drag mirror on the ship. It can't reflect anymore energy back to the drag mirror, than the mirror gets directly from earth. So It wouldn't be able to decelerate the ship. So it will have to be larger and focus the beam backward to a smaller beam. > > You say the plasma surrounds the ship, I thought they were at the TC side of > the ship. Does design looks like this: > > ) > -------------) > //) > (--------| Plasma > (--------| Plasma > \\) > ------------) > ) > > ( are the small mirror at the Earth side of the Asimov > ) are the big mirror at TC side of the Asimov > -- / \ Light rays Pretty much it. Imagine the ship as a hollow pipe with a plasma in the inside of the pipe and in frount of it. (The ship surrounds the plasma, not the other way round.) The microwaves are reflected back and inward by the forward main ring sial, toward the rear ring sail (drag sail) which reflects it forward inside the open area of the ship toward the plasma. It heats and is reflected off the plasma backward. > As soon as the photons hit the plasma how are they reflected? > > >Do you mean you don't want to use a beam system thats that inefficient? > >Efficiency in catching the beam is a luxury we can worry about later. > > Indeed, that's what I'm saying. If a system is only 10% or even 0.1% > efficient, then for example a fusion system that uses a 1:1000 ship:fuel > ratio as well. As well what? Efficency is not nessisary for a system to be usable, but a ship that needs to carry a thousand times its weight in fuel simply can't be built. > >Right > >now we're just trying to devise a system that could possibly get us there at > >all! The choice isn't going wastefully vs going efficiency, but going > >wastefully or not going at all! > > I do not agree, as I said before, the anti-matter engine WILL work. Only you > do think that it is very difficult to make anti-matter if you have the > energy available. I, on the other hand don't see a reason why this should be > so extremely difficult in 50 years. > (And if efficiency isn't that important this will certainly be an option) You've never suggested how you think such amounts of anti-matter could be made. Or how we could build such engines. Or store such amounts of antimater. 2050 is to close for us to overcome all those problems on that scale. > Another possibility could be to create an energy field (eg. a box with a lot > of photons) Then more (virtual) particles will form that may be extracted. > This method is never used because it is not so easy to create such high > energy fields, but I think it should work. Why? We've never tried any of it. > How to store the anti-matter? Just like normal matter, create anti-atoms and > anti-solids. Finally charge it and suspend it in electro/magnetic bottles. > OK, it sounds easy, but it seems to be possible. In theory, but its a big jump from theoretically possible to usable. > How to refuel? First of all, I'm not so certain that it will return. You > would be 65 when you're back on Earth while all you worked and lived for is > on TC. Just to come back and play the hero doesn't seem that much fun. > But if you really want, than you have to build a refueling station at TC. > Too difficult? All methods need to build some kind of beaming or fuel > station at TC and all are probably difficult to realize. We went around on that question a lot a few months ago. Yes you have to bring the crews back. No one would fund a suicide run without a desparte need, and we don't have one. > >Your probably right about the E18+ power being a 'show stopper' thou. I can't > >think of any reasonable scenario that would have us able to put that kind of > >power on line, in space, in about 50 years. > > I think that we have to assume that this minimum is possible, otherwise no > system is possible unless we "invent" anti-gravity, or if we use a ship that > has much less mass (which is almost impossible). > So it would be better if one the rules of the SD "discussion" was that a > minimum (unknown?) power source of 1E18 watt is available in 2040. Or limit the discussion to systems and power levels that seem likely. > >Your definitely more optimistic about nano and A.I. than I. We after all can > >and do reflect radio and microwave off ionized gas all the time. We have no > >Nano systems, and are making painfully slow progress in A.I. (A.I. first > >learned to read aloud over ten years ago.) So I do think they are unlikely > >to be mature enough in 50 years to help us much. > > We indeed do reflect radio-waves, but we do that always at a > non-perpendicular angle. I'm not sure but, I think it works worse for right > angles. > > >Actually, even if they did work, they wouldn't solve any critical problems > >for us. Just improve effecency and affordability. > > Increasing efficiency or affordability make any design more probable and > feasable. If for example the space shuttle had AI and nanotech. it would > probably much more saver, reliable and cheaper. True, but since we havn't figured out a near lightspeed ship thats more than marginaly plausible, trying to cut costs on it doesn't mater. All that would do would be to make a nonfunctional system cheaper. > If one makes such a big ship, a lot of things may go wrong and endanger the > trip. The more complex the ship, the more probable that the trip isn't > completed. NanoAI will decrease that probability significantly. But of course, Nano are about the most complex and unrepairable systems we've even theorized making. > >Like I said above, I ran some numbers off using the delta-v program on the > >LIT site, and got a 60 to 1 fuel to ship mass ration for a .2c Delta v, > >using the Bussard fusion drive motors. Thats not an impossible number (bad, > >but not impossible). So I think such a ship could be built by 2050. So we > >could get to the nearer stars. At .2c we could get to the 4.5 to 5ish ly > >stars in 22-25 years. Which should be quick enough to be do able (thou its > >pushing it!), thou the crew will probably die durring the 25 year return > >flight. > > My ratios where for acceleration AND deceleration together. > > Nearer goals would indeed make a better chance of succeeding, also it would > be a cheaper way to "test" interstellar space-trips. > The disadvantage is of course that the number of stars is much smaller and > so are the chances of finding lifeforms or habitable planets. I'm suspicious of your fuel numbers. They seem too favorable. The odds of finding lifeforms and planets are how to judge. Certainly we're only taking about a handful of stars within search range. But it seems likely all of them could have planets, and we have no idea how picky life is about where it can form. In Sol, earths a yes, Mars is a maybe (please send unbroken lab gear) Venus I'd bet strongly against. As for the rest and their moons... ?? One thing we can be sure of, none of the planets out there will be habitable. Earth wouldn't be habitable to us if we hadn't evolved here. In any event a handfull of starsystems should keep us busy for a couple decades. Obviously past 2100 all the systems were discussing will seem archaic, and our physics quite naive. > >Remember, the limitation on accelerating in a pre-launched fuel stream. Is > >how far out you can get before the fuel gets so spread out that you can't > >scoop up enough fuel to run the engines. I.E. how accuratly can you launcher > >put the fuel? A striped down ship could not only accelerate faster, getting > >to higher speeds within a given distence from the fuel launcher. It could > >also get by on less fuel, allowing it to still keep up thrust farther out > >from the fuel launcher then its heavyer brother. If the folks back home > >really like you. They will have upgraded their fuel launcher in your > >absence. Allowing you to get a usable fuel density at far farther out from > >Sol. > > I've done some calculations, these show there is not that much profit (in > energy) when one compares prelaunching with take-all-with-you (from now on > TAWY). So? It would make a critical difference in the fuel mass ratio of the ship. Kelly From popserver Tue Dec 19 23:13:17 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8619" "Tue" "19" "December" "1995" "23:51:31" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "192" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id OAA07773 for ; Tue, 19 Dec 1995 14:51:11 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05561 (5.67b/IDA-1.5 for ); Tue, 19 Dec 1995 23:51:11 +0100 Message-Id: <199512192251.AA05561@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 19 Dec 1995 23:51:31 +0100 Timothy re: Kelly Subject : Plasma mirror >>What I meant with no turning, was that it just had to reflect the beam >>STRAIGHT back. To do that is has a very precise orientation: the >>incoming beam. The mirror does not have to track a moving object, that >>is the task of the Earth beaming station. If Earth beams it to the >>Asimov, then it also aims to the mirror. because the Asimov and the >>retro-mirror are always lined up. > >That wouldn't work, but eiather way. Straight back is still a direction >to aim at, and it couldn't do it. Is it really that hard to keep the mirror straight? And still, if the beam deviates, the Asimov can still follow it (too a certain amount) by redirecting its own mirror. Doesn't this problem arise also on the Asimov itself, it too uses a big mirror to accelerate, if its mirror is a bit offside, it is out of the beam in seconds. If you move 1E8 metres in one second, only minute angles are needed to be off the "road" 1E4 metres or so. >We have no real idea whats in interstellar space, but is fair to expect a >few comets, asteroids ect; and I don't think we can plan on everything in >our way getting neatly blown out of the way. If there are indeed so many rocks that we have to worry, then we certainly should make use of them. How big do you think the chances are that any of these lumps comes even near the Asimov? >NO! A retro reflecter mirror wil not work unless the retro-mirror is much >bigger. >-If its the same size and the retro mirror is straight in frount of the > ship. > It will be in the shaddow of the ships drag mirror. So it won't 'see' > any of the beam to reflect. >-Even if its not in the line of sight. Being the same size as the drag > mirror on the ship. It can't reflect anymore energy back to the drag > mirror, > than the mirror gets directly from earth. So It wouldn't be able to > decelerate the ship. These two remarks mean that you haven't understood how I planned to make that retro-mirror! It was constructed of two mirrors at a right angle to each other... (See previous letters) A|----\ O-----------/ >> ) >> -------------) >> //) >> (--------| Plasma >> (--------| Plasma >> \\) >> ------------) >> ) >> >> ( are the small mirror at the Earth side of the Asimov >> ) are the big mirror at TC side of the Asimov >> -- / \ Light rays > >Pretty much it. Imagine the ship as a hollow pipe with a plasma in the >inside of the pipe and in frount of it. (The ship surrounds the plasma, >not the other way round.) The microwaves are reflected back and inward by >the forward main ring sial, toward the rear ring sail (drag sail) which >reflects it forward inside the open area of the ship toward the plasma. >It heats and is reflected off the plasma backward. And then after it has reflected backward? The ship needs to absorb or better to reflect the photons in the direction of TC. If it reflects straight back, then it enters the plasma pipe, that must mean trouble. Please tell me what happens after the (first) reflection on the plasma. >> Indeed, that's what I'm saying. If a system is only 10% or even 0.1% >> efficient, then for example a fusion system that uses a 1:1000 ship:fuel >> ratio as well. > >As well what? Efficency is not nessisary for a system to be usable, but a >ship that needs to carry a thousand times its weight in fuel simply can't >be built. I really don't see why, please explain. (See also the last paragraph of this letter.) >You've never suggested how you think such amounts of anti-matter could be >made. Or how we could build such engines. Or store such amounts of >antimater. 2050 is to close for us to overcome all those problems on that >scale. That means fusion is also out of the question! I've heard that the first commercial fusion power plant would be there at 2050. From there it is still a big step to scaling up such a power plant about 1E8 times. And if fusion isn't our source for the beaming station what is? A mirror-array to collect the energy of the Sun would be too large or too difficult to construct. The current electricity capacity of the world is about 3E12 Watt. So all what we have now should be scaled up 1E6 times! Finally we come to the conclusion that doing this in 2050 is completly out of the question. Even going to Alpha Centauri isn't possible, simply because we there isn't a power-source by then that can do the trick. >>How to store the anti-matter? Just like normal matter, create anti-atoms >>and anti-solids. Finally charge it and suspend it in electro/magnetic >>bottles. OK, it sounds easy, but it seems to be possible. > >In theory, but its a big jump from theoretically possible to usable. You are right. But the only experiment done with moving an object by laser light involved a mass of about a milligram. So that would mean that any lightsailing technique is not much more than theory too. What I mean is that probably none of the existing and almost-ready-to-use techniques could bring us to TC. >We went around on that question a lot a few months ago. Yes you have to >bring the crews back. No one would fund a suicide run without a desparte >need, and we don't have one. Staying there isn't necessary suicide! Going back may be a bigger risk. (On that question I didn't vote for a 2-way trip) >> I think that we have to assume that this minimum is possible, otherwise >> no system is possible unless we "invent" anti-gravity, or if we use a >> ship that has much less mass (which is almost impossible). >> So it would be better if one the rules of the SD "discussion" was that a >> minimum (unknown?) power source of 1E18 watt is available in 2040. > >Or limit the discussion to systems and power levels that seem likely. Lower power levels mean not going to TC! Lower levels mean a much longer trip, and we agreed that wasn't our goal. >> Increasing efficiency or affordability make any design more probable and >> feasable. If for example the space shuttle had AI and nanotech. it would >> probably much more saver, reliable and cheaper. > >True, but since we havn't figured out a near lightspeed ship thats more >than marginaly plausible, trying to cut costs on it doesn't mater. All >that would do would be to make a nonfunctional system cheaper. It makes a lot of difference if one needs 1000 Watt or 1000*1000 Watt. For the first a simple petrol-generator will do, but for de latter you need almost a complete power-plant. >> If one makes such a big ship, a lot of things may go wrong and endanger >> the trip. The more complex the ship, the more probable that the trip >> isn't completed. NanoAI will decrease that probability significantly. > >But of course, Nano are about the most complex and unrepairable systems >we've even theorized making. Maybe unrepairable, but there will be many of them, so one or two less doesn't matter. The strength of nano is not only their tinyness, but also their vastness (for small price? and weight). The goal will be that they become selfreproducive in a (hopefully) controlled way. >The odds of finding lifeforms and planets are how to judge. Certainly >we're only taking about a handful of stars within search range. But it >seems likely all of them could have planets, and we have no idea how picky >life is about where it can form. In Sol, earths a yes, Mars is a maybe >(please send unbroken lab gear) Venus I'd bet strongly against. As for >the rest and their moons... ?? > >One thing we can be sure of, none of the planets out there will be >habitable. Earth wouldn't be habitable to us if we hadn't evolved here. Why wouldn't they be habitable? It would be possible that there are already other forms of life there. (Not necessary intelligent) In any event a handfull of starsystems should keep us busy for a couple decades. Obviously past 2100 all the systems were discussing will seem archaic, and our physics quite naive. Probably the next century would keep us busy only by "colonizing" moon and mars. And maybe some nice asteroids for their low gravity. >> I've done some calculations, these show there is not that much profit >> (in energy) when one compares prelaunching with take-all-with-you (from >> now on TAWY). > >So? It would make a critical difference in the fuel mass ratio of the >ship. So, energy stays about the same, or even better it doesn't have to be produced it (the hydrogen) only has to be collected. Why would making a big lump of Hydrogen be so difficult? It doesn't all have to be launched from Earth (asteroids or moons?) Timothy From popserver Sat Dec 23 03:51:28 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["13039" "Fri" "22" "December" "1995" "22:43:22" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "287" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id TAA20804 for ; Fri, 22 Dec 1995 19:44:51 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id WAA23676; Fri, 22 Dec 1995 22:43:22 -0500 Message-ID: <951222224321_22042979@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Fri, 22 Dec 1995 22:43:22 -0500 Oh, any idea why the LIT site droped off the SUNSITE server again? >> Timothy re: Kelly >> Subject : Plasma mirror >> >> >>What I meant with no turning, was that it just had to reflect the beam >> >>STRAIGHT back. To do that is has a very precise orientation: the >> >>incoming beam. The mirror does not have to track a moving object, that >> >>is the task of the Earth beaming station. If Earth beams it to the >> >>Asimov, then it also aims to the mirror. because the Asimov and the >> >>retro-mirror are always lined up. >> > >> >That wouldn't work, but eiather way. Straight back is still a direction >> >to aim at, and it couldn't do it. >> >> Is it really that hard to keep the mirror straight? And still, if the beam >> deviates, the Asimov can still follow it (too a certain amount) by >> redirecting its own mirror. Its kind of like balencing a meter square sheet of aluminum foil on the blast from a fire extiquisher, and expect it to never wrinkle or twist. >> Doesn't this problem arise also on the Asimov itself, it too uses a big >> mirror to accelerate, if its mirror is a bit offside, it is out of the beam >> in seconds. If you move 1E8 metres in one second, only minute angles are >> needed to be off the "road" 1E4 metres or so. The ring sail is anchored to the ship. Sort of like a parachute. I.E. a parachute attached to a weight forms a nice shape. Cut the corts and it turns into a lose sheet flutering and twisting down. Unevenness in the beam will tend to cause the ship to difft back and forth, but aslong as the beam is far larger than the sail, and the transmitions failly even (also helped by an oversized beam). It should be managable. >> >We have no real idea whats in interstellar space, but is fair to expect a >> >few comets, asteroids ect; and I don't think we can plan on everything in >> >our way getting neatly blown out of the way. >> >> If there are indeed so many rocks that we have to worry, then we certainly >> should make use of them. How big do you think the chances are that any of >> these lumps comes even near the Asimov? How could you make use of them? Your runing past them at a relativistic speed. Hopefully the odds are low, but prudent designers assume they will have the worst possible luck. >> >NO! A retro reflecter mirror wil not work unless the retro-mirror is much >> >bigger. >> >-If its the same size and the retro mirror is straight in frount of the >> > ship. >> > It will be in the shaddow of the ships drag mirror. So it won't 'see' >> > any of the beam to reflect. >> >-Even if its not in the line of sight. Being the same size as the drag >> > mirror on the ship. It can't reflect anymore energy back to the drag >> > mirror, >> > than the mirror gets directly from earth. So It wouldn't be able to >> > decelerate the ship. >> >> These two remarks mean that you haven't understood how I planned to make >> that retro-mirror! >> It was constructed of two mirrors at a right angle to each other... (See >> previous letters) >> >> A|----\ >> O-----------/ Sorry thought that idea was droped. With this you have two mirrors flaping in the breze trying to aim at something. Your odds of aiming accuratly have droped accordingly. Also you still have to focus back toward a smaller sail on the ship. >> >> ) >> >> -------------) >> >> //) >> >> (--------| Plasma >> >> (--------| Plasma >> >> \\) >> >> ------------) >> >> ) >> >> >> >> ( are the small mirror at the Earth side of the Asimov >> >> ) are the big mirror at TC side of the Asimov >> >> -- / \ Light rays >> > >> >Pretty much it. Imagine the ship as a hollow pipe with a plasma in the >> >inside of the pipe and in frount of it. (The ship surrounds the plasma, >> >not the other way round.) The microwaves are reflected back and inward by >> >the forward main ring sial, toward the rear ring sail (drag sail) which >> >reflects it forward inside the open area of the ship toward the plasma. >> >It heats and is reflected off the plasma backward. >> >> And then after it has reflected backward? The ship needs to absorb or better >> to reflect the photons in the direction of TC. Yes. If you could work out the angles and put a flat drag sail straight behind the ship (inside the rear ring sail that reflected the energy to the plasma) that would be ideal. Assuming the plasma isn't perfectly flat (highly likely) some energy will be reflected outward and it should be accounted for in the design of the ship. >> If it reflects straight back, then it enters the plasma pipe, that must mean trouble. >> Please tell me what happens after the (first) reflection on the plasma. Ideally, the beam reflects straight back toward a flat drag sail behind the ship (and straglers bounce of the inside of the ship tpward the drag sail). The beam is then directed forward toward the plasma again, and bounces back again. The plasma gets an extra boost forward. Then the ship gets an extra push backward. (repeat until beam is lost, absorbed, or canceled out by out of phase other parts of beam.) >> >> Indeed, that's what I'm saying. If a system is only 10% or even 0.1% >> >> efficient, then for example a fusion system that uses a 1:1000 ship:fuel >> >> ratio as well. >> > >> >As well what? Efficency is not nessisary for a system to be usable, but a >> >ship that needs to carry a thousand times its weight in fuel simply can't >> >be built. >> >> I really don't see why, please explain. (See also the last paragraph of this >> letter.) Because you can't build a craft thats engines and structure are so light, strong, and powerfull; that they could carry a weight a thousand times greater than their own and accelerate it at about 1 G. As a mater of fact I'm concerned that a fusion driven ship capable of carrying 40 or 60 times its weight is overly optimistic. (But I haven't gotten aroiund to looking up the numbers in the Bussard papers.) Also of course if the energy to accelerate the fuel doesn't need to be carried in the ship, the ship can get by on less fuel. >> >You've never suggested how you think such amounts of anti-matter could be >> >made. Or how we could build such engines. Or store such amounts of >> >antimater. 2050 is to close for us to overcome all those problems on that >> >scale. >> >> That means fusion is also out of the question! I've heard that the first >> commercial fusion power plant would be there at 2050. From there it is still >> a big step to scaling up such a power plant about 1E8 times. >> And if fusion isn't our source for the beaming station what is? Fusion could be developed in a decade or so if their was any push for it. Possibly power for intersystem space craft might entice someone to invest in the R&D money for it. Though your right. Their are no current plans to do so. Nor for that matter to build enough of a space infastructure to support a project like this. But, if we had usable space launchers. There is a big pent up demand for public and comercial access to space. When that demand starts, building up to the space infastructure we'ld need. Think of how fast aviation and its infastructure developed between 1915 and 1965. >> >>How to store the anti-matter? Just like normal matter, create anti-atoms >> >>and anti-solids. Finally charge it and suspend it in electro/magnetic >> >>bottles. OK, it sounds easy, but it seems to be possible. >> > >> >In theory, but its a big jump from theoretically possible to usable. >> >> You are right. But the only experiment done with moving an object by laser >> light involved a mass of about a milligram. So that would mean that any >> lightsailing technique is not much more than theory too. Actually NASA played around with the idea on a satelight. A couple public groups were trying tyo build and launch a solar sailer in the '80's, but they never finished them. >> What I mean is that probably none of the existing and almost-ready-to-use >> techniques could bring us to TC. To T.C.? Definatly. Thats why we spent so much time on the maser mirrors and such. >> >We went around on that question a lot a few months ago. Yes you have to >> >bring the crews back. No one would fund a suicide run without a desparte >> >need, and we don't have one. >> >> Staying there isn't necessary suicide! Going back may be a bigger risk. If your planing to send yourself to somewhere you can't really live at, and can't come back from, its suicide. If you propose sending others there its murder; and no western government or major group would be allowed to launch such a mission. >> (On that question I didn't vote for a 2-way trip) >> >> >> I think that we have to assume that this minimum is possible, otherwise >> >> no system is possible unless we "invent" anti-gravity, or if we use a >> >> ship that has much less mass (which is almost impossible). >> >> So it would be better if one the rules of the SD "discussion" was that a >> >> minimum (unknown?) power source of 1E18 watt is available in 2040. >> > >> >Or limit the discussion to systems and power levels that seem likely. >> >> Lower power levels mean not going to TC! Lower levels mean a much longer >> trip, and we agreed that wasn't our goal. Agreed. >> >> Increasing efficiency or affordability make any design more probable and >> >> feasable. If for example the space shuttle had AI and nanotech. it would >> >> probably much more saver, reliable and cheaper. >> > >> >True, but since we havn't figured out a near lightspeed ship thats more >> >than marginaly plausible, trying to cut costs on it doesn't mater. All >> >that would do would be to make a nonfunctional system cheaper. >> >> It makes a lot of difference if one needs 1000 Watt or 1000*1000 Watt. For >> the first a simple petrol-generator will do, but for de latter you need >> almost a complete power-plant. If you can build one petrol (gasoline) generator, at worst you can build a thousand others and string them together for a special project. Maybe well start mass producing O'Neil type solar power sattelites. >> >> If one makes such a big ship, a lot of things may go wrong and endanger >> >> the trip. The more complex the ship, the more probable that the trip >> >> isn't completed. NanoAI will decrease that probability significantly. >> > >> >But of course, Nano are about the most complex and unrepairable systems >> >we've even theorized making. >> >> Maybe unrepairable, but there will be many of them, so one or two less >> doesn't matter. The strength of nano is not only their tinyness, but also >> their vastness (for small price? and weight). The goal will be that they >> become selfreproducive in a (hopefully) controlled way. Hopefully. Otherwise we launched a gray goo plague to T.C. ;-) Eiather way its pretty iffy tech, and doesn't solve the fundemental problems. >> >The odds of finding lifeforms and planets are hard to judge. Certainly >> >we're only taking about a handful of stars within search range. But it >> >seems likely all of them could have planets, and we have no idea how picky >> >life is about where it can form. In Sol, earths a yes, Mars is a maybe >> >(please send unbroken lab gear) Venus I'd bet strongly against. As for >> >the rest and their moons... ?? >> > >> >One thing we can be sure of, none of the planets out there will be >> >habitable. Earth wouldn't be habitable to us if we hadn't evolved here. >> >> Why wouldn't they be habitable? It would be possible that there are already >> other forms of life there. (Not necessary intelligent) Agreed. Their is a reasonable chance of finding worlds with ecologies as complex as Earth and with life forms similar to ours in size, complexity, etc... And if you could survive a couple secounds on them outside of a biosuit I'ld be stunned! The history of explorers here on this world, and our present problems with plagues like Ebola, AIDs, Etc, don't speak well for the odds of a carless interstellar explorer. Your microbes, and the planets microbes would rapibly try to digest the alien life forms it sees. >> >> In any event a handfull of starsystems should keep us busy for a >> >> couple decades. Obviously past 2100 all the systems were >> >> discussing will seem archaic, and our physics quite naive. >> >> Probably the next century would keep us busy only by "colonizing" moon and >> mars. And maybe some nice asteroids for their low gravity. True, though I think big platforms harvesting near earth asteroids and comet cores would go first. Moon and Mars lack a human healty gravity, and its much easier to ship the mined cargo from near earth objects around and much richer pickings!! (One estimate places the value of the oil on one average near earth comet core at several hundred billion dollars US!) Which is one of the reasons I expect space development to progress much faster than expected. Free-for-the-taker valuble materials tend to encourage that. ;-) Kelly From popserver Sun Dec 24 00:17:21 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11133" "Sat" "23" "December" "1995" "23:06:55" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "224" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id OAA18740 for ; Sat, 23 Dec 1995 14:06:03 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA20832 (5.67b/IDA-1.5 for ); Sat, 23 Dec 1995 23:06:45 +0100 Message-Id: <199512232206.AA20832@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 23 Dec 1995 23:06:55 +0100 >Oh, any idea why the LIT site droped off the SUNSITE server again? Yes, they had a major harddisk failure. Timothy re: Kelly Subject : Plasma mirror >> Is it really that hard to keep the mirror straight? And still, if the beam >> deviates, the Asimov can still follow it (too a certain amount) by >> redirecting its own mirror. > >Its kind of like balencing a meter square sheet of aluminum foil on the blast >from a fire extiquisher, and expect it to never wrinkle or twist. You should compare each of the 2 parts of the retro-mirror with a bridge over a valley. The mirror itself would be the road, behind the mirror there would be strenghtening structure, that would be curved just like the bridge. The mirror would stay reasonable flat just like the road that connects both sides of the valley. >The ring sail is anchored to the ship. Sort of like a parachute. I.E. a >parachute attached to a weight forms a nice shape. Cut the corts and it >turns into a lose sheet flutering and twisting down. This assumes the wind is constant and comes always from the same side without small deviations. As soon as the wind comes a bit from aside, the parachute will turn a bit so that its movement is parallel with the incoming wind. >>If there are indeed so many rocks that we have to worry, then we certainly >>should make use of them. How big do you think the chances are that any of >>these lumps comes even near the Asimov? > >How could you make use of them? Your runing past them at a relativistic >speed. Lower an anchor... :) But seriously, we have a minimum of 1E19 Watt available, with that power you could move a mountain (literal). Then why do we need so much power, we are only 2E9 kg? We move at 1E8 m/s relative to that energy, that's why. >Sorry thought that idea was droped. With this you have two mirrors flaping >in the breze trying to aim at something. Your odds of aiming accuratly have >droped accordingly. Also you still have to focus back toward a smaller sail >on the ship. I don't see why these mirrors are flapping, see also the above. >>If it reflects straight back, then it enters the plasma pipe, that must mean >>trouble. Please tell me what happens after the (first) reflection on the >>plasma. > >Ideally, the beam reflects straight back toward a flat drag sail behind the >ship (and straglers bounce of the inside of the ship tpward the drag sail). > The beam is then directed forward toward the plasma again, and bounces back >again. The plasma gets an extra boost forward. Then the ship gets an extra >push backward. (repeat until beam is lost, absorbed, or canceled out by out >of phase other parts of beam.) I assume that the plasma is replenished all the time. So at the same time that the plasma is replenished inside the plasma-pipe, there are also coming reflected photons from the TC side. Doesn't that create a problem? >Because you can't build a craft thats engines and structure are so light, >strong, and powerfull; that they could carry a weight a thousand times >greater than their own and accelerate it at about 1 G. As a mater of fact >I'm concerned that a fusion driven ship capable of carrying 40 or 60 times >its weight is overly optimistic. (But I haven't gotten aroiund to looking up >the numbers in the Bussard papers.) I don't see why you can build a craft of 1E8 kg that can propell itself but not a craft of 1E11 kg. Just scale up the engines. If that isn't possible, the initial acceleration should be less, after a while the ship gets lighter and the acceleration can be increased. >Also of course if the energy to accelerate the fuel doesn't need to be >carried in the ship, the ship can get by on less fuel. Yes, but that would involve a beaming technique. >Fusion could be developed in a decade or so if their was any push for it. > Possibly power for intersystem space craft might entice someone to invest in >the R&D money for it. Though your right. Their are no current plans to do >so. Nor for that matter to build enough of a space infastructure to support >a project like this. How much push did you have in mind? There is already much research going on. Already a few seconds of "controlled" fusion are possible. Development isn't possible yet, because not enough is known about the plasma flows that are used. >But, if we had usable space launchers. There is a big >pent up demand for public and comercial access to space. When that demand >starts, building up to the space infastructure we'ld need. Think of how fast >aviation and its infastructure developed between 1915 and 1965. You yourself told me that you can't compare past developments so easely with future developments. But I don't want to hold this against you, I also see that space will become a bigger and bigger part of the economy. I know that certain commercial firms (General Motors) are developing small easy to produce and relative cheap launchers. >Actually NASA played around with the idea on a satellite. A couple public >groups were trying tyo build and launch a solar sailer in the '80's, but they >never finished them. Wasn't there an experiment with a solarsail last month? >>What I mean is that probably none of the existing and almost-ready-to-use >>techniques could bring us to TC. > >To T.C.? Definatly. Thats why we spent so much time on the maser mirrors >and such. The mirrors might be feasable but how about the maser itself? Making a beam of 1 or 1000 kilometres in radius... that would mean a massive area filled with maser cannons. So actually the beam would consist of many small beams evenly distributed. Say we take a 100x100 km area, that is 1E10 square metres. We need a power of about 1E18 Watt per square kilometre, so if we install one maser per square metre, each maser (there would be 1E10 of them) should need a power of 1E12 Watt. So that means every maser needs its own fusion power plant, meaning 1E10 power plants. These power plants would need a total of about 5000 kg of fuel per second. This story is almost the same for Alpha Centauri as for Tau Ceti the biggest difference is the total time these masers have to be turned on. Or if you lower the acceleration you may devide all numbers by 10 or 100. I hope this makes clear why existing or almost-ready-to-use techniques are not usable. >If your planing to send yourself to somewhere you can't really live at, and >can't come back from, its suicide. If you propose sending others there its >murder; and no western government or major group would be allowed to launch >such a mission. It's just how you want to see it. Confing the crew to 15 years living in a spaceship is bad enough. Giving them another 15 years may be even worse. Probably most people would fail the psychological test only for this reason. Imagine 15 years in the same environment, always busy with the same kind of job, then finally you find a 10 whole planets to build new things. Would they really like to go back? Would it really be such a crime to let those people stay there and try to make a living? Even if it are all rotten planets (which is doubtful) it probably would be better to be there than to be in that stinking old spaceship for another 15 years If we aren't planning on staying there, why go there? If it's just to investigate it may be better to send unmanned probes. (That would be a task for AI) >>Lower power levels mean not going to TC! Lower levels mean a much longer >>trip, and we agreed that wasn't our goal. > >Agreed. So TC is out? >>It makes a lot of difference if one needs 1000 Watt or 1000*1000 Watt. For >>the first a simple petrol-generator will do, but for de latter you need >>almost a complete power-plant. > >If you can build one petrol (gasoline) generator, at worst you can build a >thousand others and string them together for a special project. Maybe well >start mass producing O'Neil type solar power sattelites. String them together, there you said it. Doing that is not as easy as you make it sound. You have to fuel them all, a mayor cloud of smoke would hang around them, no to mention the noise they would make. Other power supplies may not smoke or make noise but tying them together tends to make problems expand non-linear. For example, wires get thicker but their surface does increase at a slower rate, so the heat that is created by resistance has more difficulties to escape. >>Maybe unrepairable, but there will be many of them, so one or two less >>doesn't matter. The strength of nano is not only their tinyness, but also >>their vastness (for small price? and weight). The goal will be that they >>become selfreproducive in a (hopefully) controlled way. > >Hopefully. Otherwise we launched a gray goo plague to T.C. ;-) > >Eiather way its pretty iffy tech, and doesn't solve the fundemental problems. Safety is a fundamental problem. >Agreed. Their is a reasonable chance of finding worlds with ecologies as >complex as Earth and with life forms similar to ours in size, complexity, >etc... And if you could survive a couple secounds on them outside of a >biosuit I'ld be stunned! The history of explorers here on this world, and >our present problems with plagues like Ebola, AIDs, Etc, don't speak well for >the odds of a carless interstellar explorer. Your microbes, and the planets >microbes would rapibly try to digest the alien life forms it sees. I heard that our genes would probably be so different from independant developped species that they would mean no harm at all. But if they weren't we certainly would be able to immunize ourselves. The humane genome project would be completed by then and we would be able to detect and probably cure every virus-disease (including AIDS). The reason for the history of Earth-based explorers is that their genes are so identical to those of the species in the newly dicovered areas. >True, though I think big platforms harvesting near earth asteroids and comet >cores would go first. Moon and Mars lack a human healty gravity, and its >much easier to ship the mined cargo from near earth objects around and much >richer pickings!! (One estimate places the value of the oil on one average >near earth comet core at several hundred billion dollars US!) Which is one >of the reasons I expect space development to progress much faster than >expected. Free-for-the-taker valuble materials tend to encourage that. ;-) Comets are probably not very handy, there are few of them and they have a peculiar orbit. Asteroids would be easier but probably less rich of organic material. Do you know why comets have that much oil? Oil means organic leftovers. And if there is that much of it, that means there is a big chance of life out in the galaxy. As indeed many suggested once you start living on Mars or Moon, you can't go back to Earth easely. Maybe we should look for a low gravity object (a moon), work on the ground and sleep in orbiting space stations with artificial Earth-gravity. Or we should build massive spinning buildings that create 1g. Timothy P.S. Why does your mailer add 2 >'s and a space for replied pieces of text? It looks a bit messy... From popserver Sun Dec 24 22:51:14 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2053" "Sun" "24" "December" "1995" "13:38:30" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "47" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.2/8.7.2) with ESMTP id NAA20762 for ; Sun, 24 Dec 1995 13:32:13 -0800 (PST) Received: from sea-ts1-p16.wolfenet.com (sea-ts1-p16.wolfenet.com [204.157.98.70]) by wolfe.net (8.7.3/8.7) with SMTP id NAA14438; Sun, 24 Dec 1995 13:38:30 -0800 (PST) Message-Id: <199512242138.NAA14438@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sun, 24 Dec 1995 13:38:30 -0800 (PST) >>If your planing to send yourself to somewhere you can't really live at, and >>can't come back from, its suicide. If you propose sending others there its >>murder; and no western government or major group would be allowed to launch >>such a mission. > >It's just how you want to see it. Confing the crew to 15 years living in a >spaceship is bad enough. Giving them another 15 years may be even worse. >Probably most people would fail the psychological test only for this reason. >Imagine 15 years in the same environment, always busy with the same kind of >job, then finally you find a 10 whole planets to build new things. Would >they really like to go back? Would it really be such a crime to let those >people stay there and try to make a living? Even if it are all rotten >planets (which is doubtful) it probably would be better to be there than to >be in that stinking old spaceship for another 15 years In system travel should give us a good idea of how well people adapt to space travel. A few missions of longer and longer duration to near and then farther planets would help to see the adaptiveness of humans to prolonged space flight. By the time we sent some folks to Titan and back we could refine the problem and work on means to sidestep these. > >If we aren't planning on staying there, why go there? If it's just to >investigate it may be better to send unmanned probes. (That would be a task >for AI) I agree to this. > >So TC is out? So it would seem. >>As indeed many suggested once you start living on Mars or Moon, you can't go >back to Earth easely. Maybe we should look for a low gravity object (a >moon), work on the ground and sleep in orbiting space stations with >artificial Earth-gravity. Or we should build massive spinning buildings that >create 1g. We are going to have to establish a solarsystem based society before we would be able to convince anyone of the need to go anywhere else. Ric PS: A Happy Holiday and a Happy New Years to you all. :-) The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Tue Dec 26 05:05:20 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9161" "Mon" "25" "December" "1995" "18:48:41" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "183" "Fwd: Space Access Update #60 12/24/95 (fwd)" "^From:" nil nil "12" nil "Fwd: Space Access Update #60 12/24/95" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA21573 for ; Mon, 25 Dec 1995 15:48:51 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id SAA24789; Mon, 25 Dec 1995 18:48:41 -0500 Message-ID: <951225184840_99012300@mail06.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl Subject: Fwd: Space Access Update #60 12/24/95 (fwd) Date: Mon, 25 Dec 1995 18:48:41 -0500 --------------------- Forwarded message: From: doughtd@pr.erau.edu (Donald Doughty) Sender: delta-clipper-approval@world.std.com Reply-to: delta-clipper@europe.std.com To: delta-clipper@world.std.com (DC-X) Date: 95-12-24 23:37:37 EST ---------- Forwarded message ---------- Date: Sun, 24 Dec 1995 10:46:50 -0500 (EST) From: hvanderbilt@BIX.com To: hvanderbilt@bix.com Subject: Space Access Update #60 12/24/95 Space Access Update #60 12/24/95 Copyright 1995 by Space Access Society _______________________________________________________________________ Stories this issue: - Where Have We Been? Where's My Tape? When Is Space Access '96? (Why *has* it been ten weeks since the last SAS Update?) - What The Heck Is Going On Anyway? (Reusable Launch News Summary) -----------------------(SAS Policy Boilerplate)------------------------ Space Access Update is Space Access Society's when-there's-news publication. Space Access Society's goal is to promote affordable access to space for all, period. We believe in concentrating our resources at whatever point looks like yielding maximum progress toward this goal. Right now, we think this means working our tails off trying to get the government to build and fly a high-speed reusable rocket demonstrator, one or more "X-rockets", in the next three years, in order to quickly build up both experience with and confidence in reusable Single-Stage To Orbit (SSTO) technology. The idea is to reduce SSTO technical uncertainty (and thus development risk and cost) while at the same time increasing investor confidence, to the point where SSTO will make sense as a private commercial investment. We have reason to believe we're not far from that point now. Our major current focus is on supporting the government's fully reusable single-stage rocket technology programs, the low-speed DC-XA, and its high-speed followon, the X-33 NASA/DOD/industry cooperative project. With luck and hard work, we should see fully-reusable rocket testbeds flying into space well before the end of this decade, with practical orbital transport projects getting underway. Join us, and help us make it happen. Henry Vanderbilt, Executive Director, Space Access Society To join Space Access Society or buy the SSTO/DC-X V 3.0 video we have for sale (Two hours, includes all eight DC-X flights, X-33, DC-X and SSTO backgrounders, aerospike engine test-stand footage, plus White Sands Missile Range DC-X pre and post flight footage) mail a check to: SAS, 4855 E Warner Rd #24-150, Phoenix AZ 85044. SAS membership with direct email of Space Access Updates is $30 US per year; the SSTO V 3.0 video is $25, $5 off for SAS members, $8 extra for shipping outside the US and Canada, VHS NTSC only. For more info on our upcoming Space Access '96 conference, email: space.access@space-access.org __________________________________________________________________________ Winding Up The Year We've been hearing questions lately, wondering if we'd left the planet ahead of everyone else. We've been busy as hell with some long-term payoff work, and there's been no one earthshaking development in the affordable access field, so we let the next Update slide for a week or two... And now it's over ten weeks, and the little things happening a bit at a time have begun to add up to some interesting trends. It's Update time again - but for now, the condensed holiday version. All the full-length news and informed opinion you can stand Real Soon Now... Those of you waiting for video tapes, all the backordered version 2.0 DC-X/SSTO tapes went into the mail December 22nd. It seems unlikely they'll arrive before Christmas; our apologies for the massive delay. You will find in them a discount certificate for the 3.0 video by way of amends. The long overdue (please, no letter bombs - we bruise easily!) version 3.0 X-33/DC-X/SSTO video now looks like being ready to go to the duplicators the first week of January; backorders will be in the mail immediately thereafter. Yes, we most likely got your order; we've been holding off cashing the checks out of the remnants of a sense of decency and fair play. We hope you'll think the footage we've found is worth the wait. We hope you won't march on SAS HQ with tar and feathers in the meantime... And it's getting toward that time of year again. Our next annual conference, Space Access '96, will be happening April 26-28 1996, Friday evening through Sunday afternoon, once again in Phoenix Arizona. We're going to go bigtime aerospace one of these years, do it during the working week at a posh resort at a thousand bucks a head, but not yet - SA'96 registration is still only $80 if postmarked before January 15th, when it goes up to $90, higher at the door. SA'96 will again be at a hotel within easy shuttle-bus distance of the Phoenix airport; we're currently negotiating with several and should have one nailed down shortly. Previous attendees, tell 'em - this really is worth the trouble to attend. Phoenix is a hub for Southwest and America West, and also served by Western Pacific, Continental, United, Delta, American, etc. There's no lack of cheap airfares if you plan ahead - so be here! Meanwhile, we wish you all a warm and peaceful holiday season, and we'll sign off on that note... What? Tar and feathers? Reusable Launch News Summary Oh, all right. The capsule version of the news... DC-XA is coming along OK, albeit the minor delays are piling up to the point where we'd guess it'll be a few weeks late flying, late spring rather than early. NASA tried to cancel X-34 at the start of November, but there was no wooden stake handy (actually the White House intervened), so it lives still, more or less - development cost is climbing, performance dropping, schedule slipping, and we hear that projected ops costs are rising to more or less the same as Pegasus. Which makes sense, since X- 34 now has as many stages as a Pegasus - carrier aircraft, winged booster, two upper stages - and will likely be at least as complex to integrate and operate. X-33 is doing OK; the picture is beginning to firm up as to what might actually fly and how much it'll cost. Much more on this next Update. The X-33 draft Phase 2 CAN (phase 2 is the actual construction and flight test of one or more X-33's, starting this summer) can be found at, among other places, http://www.space-access.org, our new under- construction web page. (Please, no critiques until we've actually had time to *do* something with the site!) Comments on the draft CAN are due January 22nd; email any comments you have to us at space.access@space-access.org at least one week before that, and we'll run the interesting ones past our advisory board before finalizing SAS's formal comments. After a once-over, we think it looks pretty good; the only "gotcha" we've spotted so far is the clause linking an X-33 go-ahead next summer to continued existance of X-34. Tsk, tsk, naughty naughty, we say - that's a pretty raw attempt to hold X-33 hostage to the highly dubious X-34 project on someone's part. X-33 funding for FY'96 looks fairly assured over on the NASA side, if the HUD/VA/Independent Agencies appropriation ever gets clear of the "train wreck". In theory, there's $25m for reusable rocket work actually appropriated now over in DOD, but the DOD bill was signed only because the White House has to pay for the Bosnia expedition somehow. Look for a major, multi-billion DOD rescissions list in the coming months, and look for an attempt to put our $25m on it. And once we beat that, look for months of delay in releasing the money. This is getting to be a familiar fight, but it's one we've won every time so far. And both McDonnell-Douglas and Lockheed-Martin are investing around $300 million each of private money in upgraded expendable commercial launch vehicles (Delta 3 and Atlas 2AR respectively), and both Kistler Aerospace and Kelly Space & Technology have money and are going ahead with their private reusable space launch ventures. We just might get to the point where government funding is irrelevant to a thriving cheap launch industry sooner than anyone expects. Merry Christmas, y'all. And an interesting New Year... ____________________________________________________________________________ Space Access Society "Reach low orbit and you're halfway to anywhere 4855 E Warner Rd #24-150 in the Solar System." Phoenix AZ 85044 - Robert A. Heinlein 602 431-9283 voice/fax email: "You can't get there from here." space.access@space-access.org - Anonymous - Permission granted to redistribute the full and unaltered text of this - - piece, including the copyright and this notice. All other rights - - reserved. In other words, intact crossposting is strongly encouraged. - From popserver Tue Dec 26 05:05:26 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11387" "Mon" "25" "December" "1995" "18:48:59" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "288" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA21601 for ; Mon, 25 Dec 1995 15:49:29 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id SAA14396; Mon, 25 Dec 1995 18:48:59 -0500 Message-ID: <951225184858_23629365@emout05.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Mon, 25 Dec 1995 18:48:59 -0500 > Timothy re: Kelly > Subject : Plasma mirror > > >> Is it really that hard to keep the mirror straight? And still, if the beam > >> deviates, the Asimov can still follow it (too a certain amount) by > >> redirecting its own mirror. > > > >Its kind of like balencing a meter square sheet of aluminum foil on the blast > >from a fire extiquisher, and expect it to never wrinkle or twist. > > You should compare each of the 2 parts of the retro-mirror with a bridge > over a valley. The mirror itself would be the road, behind the mirror there > would be strenghtening structure, that would be curved just like the bridge. > The mirror would stay reasonable flat just like the road that connects both > sides of the valley. Reasonably flat, and optically flat are very different! Optically focused over light-years is even more different. Again, you can't use a 2 part retro mirror since the drag mirror on the ship has to be much smaller. > >The ring sail is anchored to the ship. Sort of like a parachute. I.E. a > >parachute attached to a weight forms a nice shape. Cut the corts and it > >turns into a lose sheet flutering and twisting down. > > This assumes the wind is constant and comes always from the same side > without small deviations. As soon as the wind comes a bit from aside, the > parachute will turn a bit so that its movement is parallel with the incoming > wind. Not a big problem with a point source beam (effectivly point source). Even given unevenness in the beam it should be handelable. > > >>If it reflects straight back, then it enters the plasma pipe, that must mean > >>trouble. Please tell me what happens after the (first) reflection on the > >>plasma. > > > >Ideally, the beam reflects straight back toward a flat drag sail behind the > >ship (and straglers bounce of the inside of the ship tpward the drag sail). > > The beam is then directed forward toward the plasma again, and bounces back > >again. The plasma gets an extra boost forward. Then the ship gets an extra > >push backward. (repeat until beam is lost, absorbed, or canceled out by out > >of phase other parts of beam.) > > I assume that the plasma is replenished all the time. So at the same time > that the plasma is replenished inside the plasma-pipe, there are also coming > reflected photons from the TC side. Doesn't that create a problem? Can't think of any. It actually should help. > >Because you can't build a craft thats engines and structure are so light, > >strong, and powerfull; that they could carry a weight a thousand times > >greater than their own and accelerate it at about 1 G. As a mater of fact > >I'm concerned that a fusion driven ship capable of carrying 40 or 60 times > >its weight is overly optimistic. (But I haven't gotten aroiund to looking up > >the numbers in the Bussard papers.) > > I don't see why you can build a craft of 1E8 kg that can propell itself but > not a craft of 1E11 kg. Just scale up the engines. If that isn't possible, > the initial acceleration should be less, after a while the ship gets lighter > and the acceleration can be increased. Its not the weight, its the mass fraction. You could scale up the craft, but not increase the fraction of its total that is fuel or cargo (well not by much). Given the speeds and time we're talking about, you can't go with a ship with lower accell. > >Also of course if the energy to accelerate the fuel doesn't need to be > >carried in the ship, the ship can get by on less fuel. > > Yes, but that would involve a beaming technique. No, I was talking about my fuel launcher idea, not a beamed power system. > >Fusion could be developed in a decade or so if their was any push for it. > > Possibly power for intersystem space craft might entice someone to invest in > >the R&D money for it. Though your right. Their are no current plans to do > >so. Nor for that matter to build enough of a space infastructure to support > >a project like this. > > How much push did you have in mind? There is already much research going on. > Already a few seconds of "controlled" fusion are possible. Development isn't > possible yet, because not enough is known about the plasma flows that are used. Actually there is very little research going on. Several areas considered more promising than magnetic confinment have no funding due to competition with established programs. In the U.S. each new model car turned out receaves more R&D funding than all of fusion. Given the abundant conventional fuel sources, alternate energy suplies get little interest. > >But, if we had usable space launchers. There is a big > >pent up demand for public and comercial access to space. When that demand > >starts, building up to the space infastructure we'ld need. Think of how fast > >aviation and its infastructure developed between 1915 and 1965. > > You yourself told me that you can't compare past developments so easely with > future developments. --- I beleave I said you should consider dissimilar past developments. > --- But I don't want to hold this against you, I also see > that space will become a bigger and bigger part of the economy. I know that > certain commercial firms (General Motors) are developing small easy to > produce and relative cheap launchers. I don't beleave G.M. has any launcher program? > >Actually NASA played around with the idea on a satellite. A couple public > >groups were trying tyo build and launch a solar sailer in the '80's, but they > >never finished them. > > Wasn't there an experiment with a solarsail last month? Not that I know of. > >If your planing to send yourself to somewhere you can't really live at, and > >can't come back from, its suicide. If you propose sending others there its > >murder; and no western government or major group would be allowed to launch > >such a mission. > > It's just how you want to see it. Confing the crew to 15 years living in a > spaceship is bad enough. Giving them another 15 years may be even worse. > Probably most people would fail the psychological test only for this reason. > Imagine 15 years in the same environment, always busy with the same kind of > job, then finally you find a 10 whole planets to build new things. Would > they really like to go back? Would it really be such a crime to let those > people stay there and try to make a living? Even if it are all rotten > planets (which is doubtful) it probably would be better to be there than to > be in that stinking old spaceship for another 15 years 10 whole planets to build what in? They would have no place to live in other than their ship. No resources to suvive in the ship for more than a few decades (and we have no ability to do better than that). How are they going to survive? What do you mean by having them "stay there and try to make a living"? What is there for them to do that would pay for their keep and supply flights? > If we aren't planning on staying there, why go there? If it's just to > investigate it may be better to send unmanned probes. (That would be > a task for AI) Your expecting a lot out of A.I.s. Humans will probably be more adaptable for some time. Also no one would fund a A.I. exploration flight. Tax payers want to see humans explorer, and lose all interest in programs without human involvement. > >>Lower power levels mean not going to TC! Lower levels mean a much longer > >>trip, and we agreed that wasn't our goal. > > > >Agreed. > > So TC is out? Seems like. > >>Maybe unrepairable, but there will be many of them, so one or two less > >>doesn't matter. The strength of nano is not only their tinyness, but also > >>their vastness (for small price? and weight). The goal will be that they > >>become selfreproducive in a (hopefully) controlled way. > > > >Hopefully. Otherwise we launched a gray goo plague to T.C. ;-) > > > >Eiather way its pretty iffy tech, and doesn't solve the fundemental problems. > > Safety is a fundamental problem. Which they don't help particularly. Thou in our case, unless you can get there at all, mission safty is a moot point. > > Their is a reasonable chance of finding worlds with ecologies as > >complex as Earth and with life forms similar to ours in size, complexity, > >etc... And if you could survive a couple secounds on them outside of a > >biosuit I'ld be stunned! The history of explorers here on this world, and > >our present problems with plagues like Ebola, AIDs, Etc, don't speak well for > >the odds of a carless interstellar explorer. Your microbes, and the planets > >microbes would rapibly try to digest the alien life forms it sees. > > I heard that our genes would probably be so different from independant > developped species that they would mean no harm at all. But if they weren't > we certainly would be able to immunize ourselves. The humane genome project > would be completed by then and we would be able to detect and probably cure > every virus-disease (including AIDS). > The reason for the history of Earth-based explorers is that their genes are > so identical to those of the species in the newly dicovered areas. No, most deseases don't interact with our genetic structure (only viruses do) the rest (molds, bacteria, fungus, etc..) just use us as chemical food or fertalizer. Here we evelved defenses against those deseases, but on an alien ecosphere the counterparts could be radically invulnerable to our defence techneques, and we'ld have no time to evolve new ones. Then again alergies, even to things we've been exposed to for centuries, can kill sometimes us in minuttes. > >True, though I think big platforms harvesting near earth asteroids and comet > >cores would go first. Moon and Mars lack a human healty gravity, and its > >much easier to ship the mined cargo from near earth objects around and much > >richer pickings!! (One estimate places the value of the oil on one average > >near earth comet core at several hundred billion dollars US!) Which is one > >of the reasons I expect space development to progress much faster than > >expected. Free-for-the-taker valuble materials tend to encourage that. ;-) > > Comets are probably not very handy, there are few of them and they have a > peculiar orbit. Asteroids would be easier but probably less rich of organic > material. Do you know why comets have that much oil? Oil means organic > leftovers. And if there is that much of it, that means there is a big chance > of life out in the galaxy. I ment near earth comet cores. Their are a few thousand of them charted, and are easyier to get to than Mars. Technically they don't hold oil, so much as a hydrocarbon sludge. But an oil refinery would process it just the same. > As indeed many suggested once you start living on Mars or Moon, you can't go > back to Earth easely. More precisely the low G would deteriorate your system. Short term you couldn't handel 1 G. Long term you die from cardiovascular, bone, and immune system deterioration. > P.S. Why does your mailer add 2 >'s and a space for replied pieces of text? > It looks a bit messy... Sorry, I thought it was clearer. Is this preferable? Kelly P.S. A, I the only one who remembers to CC Dave Levin on the address list? From popserver Tue Dec 26 18:00:57 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1931" "Tue" "26" "December" "1995" "12:28:20" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "39" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id DAA08324 for ; Tue, 26 Dec 1995 03:27:18 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15771 (5.67b/IDA-1.5 for ); Tue, 26 Dec 1995 12:28:10 +0100 Message-Id: <199512261128.AA15771@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 26 Dec 1995 12:28:20 +0100 ReplyTo : Ric >In system travel should give us a good idea of how well people adapt to >space travel. A few missions of longer and longer duration to near and then >farther planets would help to see the adaptiveness of humans to prolonged >space flight. By the time we sent some folks to Titan and back we could >refine the problem and work on means to sidestep these. Yes, that will give us a preview. But I think you don't have to wait for that: Imagine living and working in your own house, never allowed to open the door and go outside. When looking outside nothing happens, the stars almost don't change. How would you feel? How many people are there that can survive happely and healty in such an environment? Probably an important feature of the spacevessel would be that it feeled much like Earth's environment. This doesn't mean it should look the same, but several things like a leisure room, a bar, a garden of some sort (and maybe a swimming pool) also crew quarters should not be too small. In fact all kinds of things that would make the spaceship bigger and heavier would make living better. So the dilemmas are size and weight versus crew happyness and healthyness. The point is to make a spacevessel that feels like YOUR environment (home, work, shops). >>As indeed many suggested once you start living on Mars or Moon, you can't go >>back to Earth easely. Maybe we should look for a low gravity object (a >>moon), work on the ground and sleep in orbiting space stations with >>artificial Earth-gravity. Or we should build massive spinning buildings that >>create 1g. > >We are going to have to establish a solarsystem based society before we >would be able to convince anyone of the need to go anywhere else. So if we want to continue the SD project we should make it 2140 instead of 2040. Timothy P.S. Who knows the latest guess for the completion of THE spacestation (Freedom or whatever is leftover). From popserver Tue Dec 26 18:01:15 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4051" "Tue" "26" "December" "1995" "11:01:10" "-0500" "David Levine" "David@interworld.com" nil "72" "RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id HAA12024 for ; Tue, 26 Dec 1995 07:56:56 -0800 (PST) Received: by www with Microsoft Mail id <01BAD381.7A7D1690@www>; Tue, 26 Dec 1995 11:01:16 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD381.7A87EC00" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 11:01:10 -0500 ------ =_NextPart_000_01BAD381.7A87EC00 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Um, gang, you may have noticed that the LIT site has disappeared. In fact, EVERYTHING at SunSITE is --gone--. They had several major failures and are still trying to figure out what went wrong. So far it seems even the backups are unrecoverable. When they restore what they can, I was thinking about moving it all anyway. I don't know yet what's going to happen. Eventually, what I want to do (if possible... I don't know yet), is bring my Linux machine (a 100mhz pentium) into work, plug it in to the network, and give all you guys some disk space and an account. This way LIT can be a much more collaborative thing. Anyway, if that doesn't happen, I'll still find out a way to get as much back on-line as I can. And I don't know if I've gotten all the "issues" of this version of the newsletter - - but when we're back up, if anyone's been archiving the stuff (I've been keeping what I've been getting), please send it to me. One of my big projects at work has been a very powerful search engine... and guess what huge archive is going to benefit from this search engine.... -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD381.7A87EC00 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IhEQAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaAAsA AQAKAAIAEAEBCYABACEAAABBNTM2NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMAA3BwEggAMA DgAAAMsHDAAaAAsAAQAQAAIAFgEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAGwAAAFJFOiBFbmdpbmVlcmluZyBOZXdzbGV0dGVyAKkJAQ2ABAACAAAAAgACAAEDkAYAgAYA ABIAAAALACMAAAAAAAsAKQAAAAAAAwAmAAAAAAADADYAAAAAAB4AcAABAAAAFwAAAEVuZ2luZWVy aW5nIE5ld3NsZXR0ZXIAAAIBcQABAAAAGwAAAAG60yQDyPZuNmk6vBHPrAgAgF8UovAAIYJysQAD AAYQYM1+KgMABxC3AwAAHgAIEAEAAABlAAAAVU0sR0FORyxZT1VNQVlIQVZFTk9USUNFRFRIQVRU SEVMSVRTSVRFSEFTRElTQVBQRUFSRURJTkZBQ1QsRVZFUllUSElOR0FUU1VOU0lURUlTLS1HT05F LS1USEVZSEFEU0VWRQAAAAADABAQAAAAAAMAERADAAAAAgEJEAEAAADYBAAA1AQAAM0HAABMWkZ1 1ElmjP8ACgEPAhUCqAXrAoMAUALyCQIAY2gKwHNldDI3BgAGwwKDMgPFAgBwckJxEeJzdGVtAoMz 9wLkBxMCgzQDRRM1B20CgzY1A8YUyDYSzA/fZjerEswUyDgRDDEZrn0KgMsIzwnZOx85MTIcYAoy xyERIFoKFDI1NQKACoGDDbELYG5nMTAzFFAXCwoUUQvyYxKgIFVtWCwgZyOhJbB5CGAgCQDAeSAR gHZlIG6Qb3RpYwmAIHQRgIcFQCeAJuBMSVQgAJAXE9AmoQQgZAQAYXBwVmUKwAmALgqFSQOgZgUA 0HQlsEVWRVJZQFRISU5HICehU0h1blMoIEUgBAAgKC0tZwIgZSwwLiC/FkAn4CaSJ2ARsCbQcgdA +wqFAMBqBbEqQAMQCHAHkV8AcCdgKVEoQCcgbAMgdFRyeQuAZydwbyowaVpnLvEgCGAFQHcnknef CfAxUQNgI7AssVNvCoX/KkAFwChgLWET4AQgLYEDoMUn0mIA0Gt1cC8hL5FfK5AfQAWgLZICYGUs sVf/J+A0IyaQLwEwkB9ACoUxc+02k2MAcCWwSTFgKLEngL0LgGswUgGgMTIEYHYwUq8zYQdAAyAA cHk40HkssVU4sGQCICcFQGsnAHftCoV5EcAxYycEICxQMFUrEYApIW4ssUU0AXR1/TqheSWwMXM4 sjHhMJE7kEQgKAaQIHBvBBBp3zXiQRAppjuJPJIpJbAsAVZiBRAwYW0mkEwLgHUeeCZhEXALgCbg KGEgYSPQMG1oekCAMdFpuHVtKSvwAjAypncFsPZrJbALUHU6UwuAMIIn0s0scHRGZC9CZ2km0Tqi fyYyMOATsChAA3Am4Cjha/8oQAqwJ0AKhS9DA6AA0AWg/SuQdCyzLAE7ESgDOGE0cPtI4SZgdRFw OfEvkR6xC2B/BuAtsCcgJtE5EjJQCoVB/zrzQsFAcCeDO5AHkDuyPeT9OJEnL/EvxDDAL1ExMkSQ +0ySMJFnPLEosU2iCoU0gvExIG4tbERCKLE4sDhh/ymWT4cnYEG7QGFR8CbRLFBvAkA0ETqiJ9Ii BAEKUHP+IjEgUIIsAS2RAJACIFokczdGLHB3czXwWNEFwC3dXKFiMUM0ETHAJy+RVON/NMBQUzrh LGE9IU1QWPJy30QhOiIKhSfSE8B1DdBAQOtYY18zawngcDBSPzRhR/9TwScgI7BCsQtQKUARsC1h Py9RKGBgFjCgB4AssSBPd0RRWjFDcWIw0ECAA2Bq/QWQdC8hMVFGcSiTXzRaoscmkECQMcByZnUt 1hGw/1+CM+AjsERBQRFIZFnhTHH9J5JoRuBI4V+TJuAsAT1X/01QLHAwwGS2A1JaVGmuVj3zCvRV YDM2DfAkf3AsC1X9GMIxGMAlUHFBA2AT0Cpg/ywhC0Ya0nQDAFAAoHR2cod/C2QVYQvwErB0Mgww dHZE9SbAaSdgTC2AREFPhikg71VgOGAnIFsBRWojXIMqEOVccVcFsGxkdu9393R2gmgCQHA6Ly93 fvBeLkWxBJBGYXxALgWgbUovE8BhDdAvZHkyL9983wBQdm98/3ZISE8BCIH/J2EwoDlQL/FJ8QPw J4BNcf8CEEaAVWABgEEYC0YcYXPwFxrQgh0eYQCJwEAAOQDQjwRgq9O6AQIBRwABAAAANQAAAGM9 VVM7YT0gO3A9SW50ZXJXb3JsZDtsPVByaXZhdGUgTURCLTk1MTIyNjE2MDExMVotNDAAAAAAQAAH MHAtA2Cr07oBQAAIMGCKYmOr07oBHgA9AAEAAAAFAAAAUkU6IAAAAAACARQ0AQAAABAAAABUlKHA KX8QG6WHCAArKiUXTAc= ------ =_NextPart_000_01BAD381.7A87EC00-- From popserver Tue Dec 26 18:01:25 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8463" "Tue" "26" "December" "1995" "17:55:01" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "192" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id IAA13361 for ; Tue, 26 Dec 1995 08:54:06 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA20859 (5.67b/IDA-1.5 for ); Tue, 26 Dec 1995 17:54:55 +0100 Message-Id: <199512261654.AA20859@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Tue, 26 Dec 1995 17:55:01 +0100 Timothy re : Kelly Subject : Plasma mirror >Reasonably flat, and optically flat are very different! Optically focused >over light-years is even more different. OK, I give up... I hoped that this this unflatness would not be too big. But If you can't make a mirror that is flat enough than you can't make a curved mirror that is curved enough. So a curved mirror would spread the light just as much as a flat mirror. So this means that ANY mirror that works over a larger distance is out of the question! >Again, you can't use a 2 part retro mirror since the drag mirror on the ship >has to be much smaller. No, because the two parts of the retro-mirror could have been place further apart (but makes the construction not easier). Beam that missed the mirror || || / || \ A / || \ B Two mirrors A and B at a perpendicular angle /__________________\ but at some distance from each other /|____________________|\ / || || || \ || || || || || || || /\ /\ \/ Beams from Earth Beam to Earth _______ XX XX XX The Asimov The mirrors are connected in some rigid way! >>I assume that the plasma is replenished all the time. So at the same time >>that the plasma is replenished inside the plasma-pipe, there are also coming >>reflected photons from the TC side. Doesn't that create a problem? > >Can't think of any. It actually should help. After rethinking it, I see what you mean. The only thing I'm not sure about is what the physics of plasma reflection are. We may reflect radio-waves to the ionosphere everyday but how does it work? And does it work in the Asimov also? I don't know how big the plasma-tube is going to be but at certain radiation-densities materials get blown up, so you don't even need to ionize the molecules yourself to create a plasma. >Its not the weight, its the mass fraction. You could scale up the craft, but >not increase the fraction of its total that is fuel or cargo (well not by >much). Given the speeds and time we're talking about, you can't go with a >ship with lower accell. Yes, I understood that. But do the engines take the most of the weight? Or in other words, what percentage of the ship (without fuel) is reserved for the engine? If that percentage is small it may be possible to scale up the engines a bit. But indeed there is a limit, only where is that limit? Ideally the weight of the engine grows slower than its power: Make an engine twice as big doubles the power, but the weight increases with the squareroot of 2. > > >Also of course if the energy to accelerate the fuel doesn't need to be > > >carried in the ship, the ship can get by on less fuel. > > > > Yes, but that would involve a beaming technique. > >No, I was talking about my fuel launcher idea, not a beamed power system. Probably launching is even more difficult than beaming. >>How much push did you have in mind? There is already much research going on. >>Already a few seconds of "controlled" fusion are possible. Development isn't >>possible yet, because not enough is known about the plasma flows that are >>used. > >Actually there is very little research going on. Several areas considered >more promising than magnetic confinment have no funding due to competition >with established programs. In the U.S. each new model car turned out >receaves more R&D funding than all of fusion. Given the abundant conventional >fuel sources, alternate energy suplies get little interest. Here in the Europe (also in the Netherlands) there are several institutes busy. Most of the research is in a very early stage. Spending more money may help a bit but not that much as you would hope. Some things just can't go any faster. Besides that, it is not fair to assume that money alone can change research that fast, otherwise antimatter may become a possibility too. >I don't beleave G.M. has any launcher program? You're right, after some research and your forwarded letter, I figured it was the X-33 that I had in mind, and GM should be Lockheed Martin Skunk Works, McDonnell Douglas Aerospace and Rockwell International Corp. >>Wasn't there an experiment with a solarsail last month? > >Not that I know of. I will try finding some info, if I know more I'll let you know. >10 whole planets to build what in? They would have no place to live in other >than their ship. No resources to suvive in the ship for more than a few >decades (and we have no ability to do better than that). How are they going >to survive? What do you mean by having them "stay there and try to make a >living"? What is there for them to do that would pay for their keep and >supply flights? My guess was that they would construct a pre-fab habitat and from there they would expand. Being on a planet gives you much more resources and savety than a spaceship. Not all planets will be equal favourable, but a solid planet the size of Earth will be better than a spaceship after the main habitats are equipped. > > If we aren't planning on staying there, why go there? If it's just to > > investigate it may be better to send unmanned probes. (That would be > > a task for AI) > >Your expecting a lot out of A.I.s. Humans will probably be more adaptable >for some time. Also no one would fund a A.I. exploration flight. Tax payers >want to see humans explorer, and lose all interest in programs without human >involvement. To see? There won't be a live television show with interactive conversations. By the time Earth gets the first message of landing, the crew is already on their way back. Also would you pay money now to see a spectacular show that happens in 30 years? And indeed I am expecting a lot of AI, humans may be more adaptable for a while, but have lots of limitations that "machines" don't have. >> So TC is out? > >Seems like. So where to and when is our new goal? Until now only fusion may bring us out of the solar system within reasonable time. Even if you use a beam, the fusion is necessary to maintain the beam. >No, most deseases don't interact with our genetic structure (only viruses do) >the rest (molds, bacteria, fungus, etc..) just use us as chemical food or >fertalizer. Here we evelved defenses against those deseases, but on an alien >ecosphere the counterparts could be radically invulnerable to our defence >techneques, and we'ld have no time to evolve new ones. > >Then again alergies, even to things we've been exposed to for centuries, can >kill sometimes us in minuttes. Is there any hope for us? Our best hope was to find a living planet, full of life and oxigen. Now it seems that it is better to find a barren planet with no life at all. Do we indeed have not enough time to develop a anti-bodies against these diseases? We indeed should be very careful, but that doesn't mean that after we have found most anti-bodies we can live there. >I ment near earth comet cores. Their are a few thousand of them charted, and >are easyier to get to than Mars. Comet cores? I'm not sure anymore what you mean, what kind of orbit do they have? Elliptical or (near) circular? And do they turn around the Sun or the Earth? How big are they? >More precisely the low G would deteriorate your system. Short term you >couldn't handel 1 G. Long term you die from cardiovascular, bone, and immune >system deterioration. Oh, I didn't know that it was that serious. But I assume we can adapt to a thirth of Earth's gravity or is that still to little? >Sorry, I thought it was clearer. Is this preferable? Unfortunately not, the problem was not the double > but the three (>> ) characters added, that makes that all lines are broken off and one word is shown on the next line. If the you add only one > (no spaces) this word-wrap happens less often. Probably Steve has "trouble" with everyone because he use lines of 60 characters or so. >P.S. >A, I the only one who remembers to CC Dave Levin on the address list? I've never received a (personal) notice from Dave, he just left me (us?) in the dark and I always had to hear from some others that they had made contact with him. The least he could have done was send a (general) note telling he had no time for the SD-project anymore. In fact the only message I got from him was the one of December 17th. So in short, I'm a disappointed by Dave's performance. Timothy From popserver Tue Dec 26 18:01:31 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1785" "Tue" "26" "December" "1995" "11:09:19" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "26" "possible LIT site." "^From:" nil nil "12" nil "possible LIT site." nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id JAA13724 for ; Tue, 26 Dec 1995 09:09:04 -0800 (PST) Received: by maroon.tc.umn.edu; Tue, 26 Dec 95 11:09:20 -0600 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: David Levine cc: "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: possible LIT site. Date: Tue, 26 Dec 1995 11:09:19 -0600 (CST) Ok, I have 10 Meg of Web space, I don't have a forms capability yet, but I imagine that if I had a legitamate reason for needing it, then it would be granted (and maybe some more disk space to boot.) let me know if This would work, so I can get started on the begging asa soon as possible. If you want, you can get everything but the forms stuff right now, my only limit is 10 megs. Perhaps now would be the time to talk about paying our way. I would be willing to part with $20.00 (US) per year to see this continue. (of course getting the web space for free is better, but if we are paying our own way, then we'd have the right to expect it to be up, or complain if it was not) I am just throwing the $20 figure out as my personal resistance point. beyond that, i don't think i could afford it. I'm just a poor college student! ideally, the webspace cost should be split as many ways as we can, and those who contribute get nothing more than name recognition (and maybe the right to put a link on the LIT web page -- Hmm.... Kinda like advertising. no, scratch that. A lot like advertising) maybe we could approach various aerospace companies and get them to help defray the cost, they could then put links to their web pages. A few tens of megabytes of webspace shoud not be that expensive, I've seen quotes in various magazines from $30 (US) for 10 MB on up. I would think that for as little as $100 a year, we could have a very nice website with lots and lots of room. Counting heads that i see here often, (no pressure, I'm just thinking out loud) me, Dave, Kelly, Ric, Timothy, Steve. That's 6 people who contribute regularly, would bring the price down to $16.67 each. the more people who help, the less each of us would have to pay. From popserver Tue Dec 26 18:01:33 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2139" "Tue" "26" "December" "1995" "12:18:04" "-0500" "David Levine" "David@interworld.com" nil "43" "RE: possible LIT site." "^From:" nil nil "12" nil "possible LIT site." nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id JAA13822 for ; Tue, 26 Dec 1995 09:13:41 -0800 (PST) Received: by www with Microsoft Mail id <01BAD38C.376EA430@www>; Tue, 26 Dec 1995 12:18:08 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD38C.3774BEB0" From: David Levine To: "'Kevin C Houston'" Cc: "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "T.L.G.vanderLinden@student.utwente.nl" Cc: "zkulpa@zmit1.ippt.gov.pl" Subject: RE: possible LIT site. Date: Tue, 26 Dec 1995 12:18:04 -0500 ------ =_NextPart_000_01BAD38C.3774BEB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable It definitely sounds like an interesting possibility, but let me see if I= can get something set up at work first. Free is always better. -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD38C.3774BEB0 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IgkRAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaAAwA EgAEAAIAHAEBCYABACEAAABCRTM2NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMABIBwEggAMA DgAAAMsHDAAaAAwAEgAIAAIAIAEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAFwAAAFJFOiBwb3NzaWJsZSBMSVQgc2l0ZS4AXgcBDYAEAAIAAAACAAIAAQOQBgCwAwAAEgAA AAsAIwAAAAAACwApAAAAAAADACYAAAAAAAMANgAAAAAAHgBwAAEAAAATAAAAcG9zc2libGUgTElU IHNpdGUuAAACAXEAAQAAABsAAAAButO1g1n2bja9OrwRz6wIAIBfFKLwAAAN/PIAAwAGELCrzsYD AAcQ2QAAAB4ACBABAAAAZQAAAElUREVGSU5JVEVMWVNPVU5EU0xJS0VBTklOVEVSRVNUSU5HUE9T U0lCSUxJVFksQlVUTEVUTUVTRUVJRklDQU5HRVRTT01FVEhJTkdTRVRVUEFUV09SS0ZJUlNURlJF RUlTQUwAAAAAAwAQEAAAAAADABEQAwAAAAIBCRABAAAACwIAAAcCAACyAwAATFpGdSZ+SeD/AAoB DwIVAqgF6wKDAFAC8gkCAGNoCsBzZXQyNwYABsMCgzIDxQIAcHJCcRHic3RlbQKDM/cC5AcTAoM0 A0UTNQdtAoM2NQPGFMg2EswP32Y3qxLMFMg4EQwxGa59CoDLCM8J2TsfOTEyHGAKMschESBaChQy NTUCgAqBgw2xC2BuZzEwMxRQlwsKFFEL8mMSoCBJBUALDbELgGkT0Gx5IHMJCGBuZAQgbGlrZX4g A5ELgBPQH0ATwAuAZ8ggcG8EEGliAxAmEKB5LCBidQVAbBHAXiAHgCZgCeAnUGYlgCB6YwORZxHA CoUmcAeAdMZoJ+IRsSB1cCcgBUAydwWwayAl4BGgdC54ICBGCdEnUAQgB0B33mETsCjgEcAngS4K iybg7DM2DfAkfyAKjwuRGMK+MRjAJVAvkQNgE9BjBUD8LS0LRhrSMlMAUACgMsb/MNcLZBVhC/AS sDKCDDAyxgBEYXZpZCBMZUk3kG5lMNVBcAtQaecqMCfQAiAgRSOwOAEEkJczMCWAJ3JXBbBsZDU/ CzZHMsZoAkBwOi8vunc9QC4nYyxROpAuBaCUbS8TwGEN0C9kN4K+LzsvAFA0vztPNJhIJxCGdAiB N7B0byBrAxD/AyApcQPwK1AnICyQLGEm4P0BgC5FUEDtHGEyQBrQQG0FHmEASBAAQAA5AHAj7x22 07oBAgFHAAEAAAA1AAAAYz1VUzthPSA7cD1JbnRlcldvcmxkO2w9UHJpdmF0ZSBNREItOTUxMjI2 MTcxODA0Wi00MQAAAABAAAcw8MHtHbbTugFAAAgwMOBKILbTugEeAD0AAQAAAAUAAABSRTogAAAA AAIBFDQBAAAAEAAAAFSUocApfxAbpYcIACsqJRcXAA== ------ =_NextPart_000_01BAD38C.3774BEB0-- From popserver Tue Dec 26 19:12:25 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5384" "Tue" "26" "December" "1995" "13:06:58" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "99" "RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id LAA17932 for ; Tue, 26 Dec 1995 11:06:43 -0800 (PST) Received: by maroon.tc.umn.edu; Tue, 26 Dec 95 13:06:59 -0600 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: David Levine cc: "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 13:06:58 -0600 (CST) To: All Re: various. Bio interaction between earth and E.T. organisms. first, I believe that any viral infection is not possible, due to the totally arbitrary rna to protien coding system that earth biology uses. Of course all this assumes that the ET biology uses DNA/RNA Glucose ATP systems, but i do have sound Therodynamic/chemical reasons for thinking this is the case. bacteria/fungi on the other hand may pose a serious threat suposing that our systems are even remotely similar, I think it will come down to how long that particular ecosystem has been evolving. if it has been a hort while, then i think that or immune responeses will likely have seen a particular attack statagy before, and will know what to do. if the ET biology has been around longer than us, then I suspect that we will be more vulnerable. however, many earthly bacteria exploit specific weaknesses in our defenses in order to enter our systems. Alien bacteria would not be designed for this. Also, our immune system would probably go into hyperdrive if it was presented with a truely alien protein. I believe that Kelly is right when he identifies allergic reactions as one of the main health problems to be faced. This doesn't even consider what a nasty little fungus like yeast (deposited on the ground the first time you tried to spit out the foul smelling pollen that was making your throat squeeze shut) would do to an alien ecosytem. you might think it's kinda cute the way they take sugar and make alcohol, but I'll bet that just about every other biosystem we ever encounter will think that it's a vile poison. and won't have any idea that making penicillin would get rid of it. this is not to say that a alien ecosystem would be totally useless to us. who know what wonders we may find. how bout an organism that can "grow" silicon chips? of solar cells? perhaps some organism lives in a metal rich environment and can really concentrate metal ores. Perhaps, perhaps, perhaps. I could go on all day, how bout a critter that _likes_ 70 % ethanol (I'll bet that many companies would love to make brandy without having to distill) bacteria that excrete oil, or plastic, or ones that prefer it as a food source. the list goes on and on, and I'm very willing to bet that none of these creatures will be the first exploitable alien lifeform. and I'd further bet that the universe is not only stranger than I imagined, it's stranger than i _can_ imagine. In short, A totally barren 1 G planent would be ideal for colonization, but totally boring for study. To: all Re: mission Ok, I think we all have come slam up against a brick wall. Sending 1 E+09 Kg _any_ distance and coming back to rest WRT the target system is turning into a Herculean task. The charter says that we have remote sensing clues of a biosphere. we also have a public mandate for sending some people there to study it. I think perhaps it's time to either put the "Asimov" on a diet, or approach the problem from the other end. To put the "Asimov" on a diet, I'd suggest at least a thousand fold reduction in payload down to 1E+05 Kg I think this rules out self sustained mission, and requires a return. I still think we can go at 1 G, and use a MARS for the engine, but in order to over come the photon thrust, we're going to have to bring more reaction mass ( and use a slower exhaust velocity). for the return trip, I'd suggest scrapping the lineac entirely, and relying on photonic thrust for both portions of the trip. this means that some payload capacity will have to be devoted to maser transmitter control packages, but i don't see this as a real problem. the crew should be pared down to no more than 100 people, and the return module can totaly scrap the hab ring which can then be left in the target system as a stepping stone for a follow up crew if one is deemed desirable I'll follow this up with some hard numbers later,But, one thing that strikes me off hand is this, for reflection, p= 2E/C this is great for acelerating. for absorbtion, p=E/C this is a smaller amount of photonic thrust to overcome. so for example, a energy beam that provides 10 m/s^2 acceleration via light pressure only needs a 15 m/s^s deceleration from the engines to equal 10 m/s^2 total. and if it takes a 1000 to 1 RM to payload ratio, then that is the cost. and we just have to live with it. but once you get 100 people and a number of maser arrays in orbit around another star system, then sending a follow up mission is relatively easy the second option is to design this mission as if we had _no_ long range information on nearby systems, and design a small ~ 5000 Kg robot. to explore nearby systems, and return pictures and other information about every system in a 20 ly. radius. we might not have to slow down entirely, a .5 C flyby might work here. and perhaps a magnetic turning might work for some long range steering. The robots should be small and low-cost, so that is we lose a few, it's no biggie. then to luanch, we could use a particle luancher, (just like a solar sail, but you use charged particles and a heavier acceleration factor) and once the probes are up to speed, we don't bother with them again. well, my connection is getting slow, so I'll send this and wait til I get home to send the rest. Kevin From popserver Tue Dec 26 23:17:42 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["290" "Tue" "26" "December" "1995" "18:13:43" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "6" "Re: RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA28137 for ; Tue, 26 Dec 1995 15:13:13 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id SAA05198; Tue, 26 Dec 1995 18:13:43 -0500 Message-ID: <951226181342_79266998@emout04.mail.aol.com> From: KellySt@aol.com To: David@interworld.com, hous0042@maroon.tc.umn.edu, jim@bogie2.bio.purdue.edu, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 18:13:43 -0500 Sunsite lost the archives TOO!!? You've got to be kidding? I was woundering what happend. One day I signed on to use some of the software, and the next day it said it could find LIT. I hope you have a lot of back ups? I think I have about all of the newsletters, if that helps. Kelly From popserver Tue Dec 26 23:17:43 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["15625" "Tue" "26" "December" "1995" "18:13:34" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "313" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA28198 for ; Tue, 26 Dec 1995 15:14:11 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id SAA07175; Tue, 26 Dec 1995 18:13:34 -0500 Message-ID: <951226181334_79266919@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Tue, 26 Dec 1995 18:13:34 -0500 Kelly Re Timothy >> Timothy re : Kelly >>Subject : Plasma mirror >> >>>Reasonably flat, and optically flat are very different! Optically focused >>>over light-years is even more different. >> >>OK, I give up... I hoped that this this unflatness would not be too big. >>But If you can't make a mirror that is flat enough than you can't make a >>curved mirror that is curved enough. So a curved mirror would spread >>the light just as much as a flat mirror. So this means that ANY mirror >>that works over a larger distance is out of the question! Seems unavoidable. >>>>I assume that the plasma is replenished all the time. So at the same time >>>>that the plasma is replenished inside the plasma-pipe, there are also coming >>>>reflected photons from the TC side. Doesn't that create a problem? >>> >>>Can't think of any. It actually should help. >> >>After rethinking it, I see what you mean. >>The only thing I'm not sure about is what the physics of plasma reflection >>are. We may reflect radio-waves to the ionosphere everyday but how does it >>work? And does it work in the Asimov also? It would certainly involve a much larger scale, and I don't know what the reflection efficency is. Or how much mass would need to be ionized to keep up the reflection. One thing for certain, the stuff will be HOT! >>>Its not the weight, its the mass fraction. You could scale up the craft, but >>>not increase the fraction of its total that is fuel or cargo (well not by >>>much). Given the speeds and time we're talking about, you can't go with a >>>ship with lower accell. >> >>Yes, I understood that. But do the engines take the most of the weight? Or >>in other words, what percentage of the ship (without fuel) is reserved for >>the engine? If that percentage is small it may be possible to scale up the >>engines a bit. But indeed there is a limit, only where is that limit? >>Ideally the weight of the engine grows slower than its power: Make an engine >>twice as big doubles the power, but the weight increases with the squareroot >>of 2. Hard to say. The best engines Iever heard of were liquid fueld rocket engines. The engines can produce thrust over a hundred times their own weight. The Bussard fusion/electrics produce about 6 times their weight. But scaled up and eliminatring the weight of the vacume chamber might make it up to the 10's to 1 ration? (I hope.) >>>>How much push did you have in mind? There is already much research >>>>going on. Already a few seconds of "controlled" fusion are possible. >>>>Development isn't possible yet, because not enough is known about the >>>>plasma flows that are used. >>> >>>Actually there is very little research going on. Several areas >>>considered more promising than magnetic confinment have no funding >>>due to competitionwith established programs. In the U.S. each new >>>model car turned out receaves more R&D funding than all of fusion. >>>Given the abundant conventional fuel sources, alternate energy suplies >>>get little interest. >> >>Here in the Europe (also in the Netherlands) there are several institutes >>busy. Most of the research is in a very early stage. Spending more money >>may help a bit but not that much as you would hope. Some things just >>can't go any faster. Besides that, it is not fair to assume that money >>alone can change research that fast, otherwise antimatter may become >>a possibility too. That would be true if all major areas of research were being investigated and resonably well funded. But most areas of fusion research that I know of have no funding. Magnetic plasma fusion is geting funded, but at least in the US the systems are dead ends. Even if they worked they'ld be useless (to large to be intergrated into the power grid.). Where as more inovative designs that are considered more promising (like Bussards among others) are geting no funding. >>>I don't beleave G.M. has any launcher program? >> >>You're right, after some research and your forwarded letter, I figured it >>was the X-33 that I had in mind, and GM should be Lockheed Martin Skunk >>Works, McDonnell Douglas Aerospace and Rockwell International Corp. Oh yeah, the single stage to orbit program (SSTO). My excorperation, and the NASA department I used to work at in NASA headquarters were working on that program. Increadable potential. It could cut costs to orbit by a factor of 100! Fed Ex is even rumored to be seriously interested in using them for suborbital intercontenental mail carriers. >>>10 whole planets to build what in? They would have no place to live in >>>other than their ship. No resources to suvive in the ship for more than >>>a few decades (and we have no ability to do better than that). How are >>>they going to survive? What do you mean by having them "stay there >>>and try to make a living"? What is there for them to do that would pay >>>for their keep and supply flights? >> >>My guess was that they would construct a pre-fab habitat and from >>there they would expand. Being on a planet gives you much more >>resources and savety than a spaceship. Not all planets will be equal >>favourable, but a solid planet the size of Earth will be better than a >>spaceship after the main habitats are equipped. I'ld debate that. Since your stuck in an artificial habitat anyway, one in space has easy access to all the floating ores and raw materials in the solar system. Much of which would be hard to get at on a planet (ever see a strip mine) and much harder to transport. I'm a firm beleaver that heavy industry will largely move off earth in a century or two. If your already off planet and in a starship, trying to set up on a planet would be hellish. >>> > If we aren't planning on staying there, why go there? If it's just to >>> > investigate it may be better to send unmanned probes. (That would >>> > be a task for AI) >>> >>>Your expecting a lot out of A.I.s. Humans will probably be more >>>adaptable for some time. Also no one would fund a A.I. exploration >>>flight. Tax payers want to see humans explorer, and lose all interest >>>in programs without human involvement. >> >>To see? There won't be a live television show with interactive >>conversations. By the time Earth gets the first message of landing, the >>crew is already on their way back. Also would you pay money now to see >>a spectacular show that happens in 30 years? People won't see it right away, but they will know people are out there. I think that would be enough to get public interest. I know public interest in robot probes is near nill. As NASA constantly found. Robots were thought of as scout craft for maned expiditions. If no manned folowups were planed (and frequently mentioned) public interest in funding the robots droped way off. Generally a so what atitude. Drove the Robot probe teams CRAZY! >>>> So TC is out? >>> >>>Seems like. >> >>So where to and when is our new goal? Until now only fusion may bring >>us out of the solar system within reasonable time. Even if you use a >>beam, the fusion is necessary to maintain the beam. Well you could power the beam with big solar electric power platforms in space. (The kind of stuff the L-5 socyety kept proposing to power earth.) >>>No, most deseases don't interact with our genetic structure (only viruses do) >>>the rest (molds, bacteria, fungus, etc..) just use us as chemical food or >>>fertalizer. Here we evelved defenses against those deseases, but on an >>>alien ecosphere the counterparts could be radically invulnerable to our >>>defence techneques, and we'ld have no time to evolve new ones. >>> >>>Then again alergies, even to things we've been exposed to for >>>centuries, can kill sometimes us in minuttes. >> >>Is there any hope for us? Our best hope was to find a living planet, full >>of life and oxigen. Now it seems that it is better to find a barren planet >>with no life at all. I would definatly prefer a dead world as a possible colony site over a lush one like earth. Wouldn't be as interesting to study, but much more survivable. The problem is any world that could support us, probably has life. >>Do we indeed have not enough time to develop a anti-bodies against >> these diseases? We indeed should be very careful, but that doesn't >> mean that after we have found most anti-bodies we can live there. Hell, we're still trying to find cures for all the plagues on earth. So far our best luck seem to be in destroying the worst sections of the ecology (draining wetlands, fogging everything with pestasides, etc..) and building urban semi-ecologies. Most of the habited areas of the developed world (europe, North America, etc..) do this so routinely we don't even notice anymore. But then living in a coutry thats largly under sea level I hardly have to tell you. ;) >>>I ment near earth comet cores. Their are a few thousand of them >>>charted, and are easyier to get to than Mars. >> >>Comet cores? I'm not sure anymore what you mean, what kind of orbit >>do they have? Elliptical or (near) circular? And do they turn around the >>Sun or the Earth? How big are they? Near earth in that the inner part of their orbit come in near to earths orbit, or farther in than it. The outer orbits are generally farther in then jupiter. Somethimes closer in than Mars. After bein in that close for a while. Most of the light volitals melt away, and the outer surface gets covered over by rock. That crust helps shield the reset from sunlight. Compasition is estimated (by weight) at 1/3rd water ice, 1/3rd rock and metalic ores, 1/3rd hydrocarbon sludge (thick cride oil). Size varies. 5 kilometer across ones are fairly common. (Weight 50 billion metric tons.) Estimates are about that there are a few thousand about that size in near earth space. Possibly more asteroids. (It surprising we don't get more impacts!) >>>More precisely the low G would deteriorate your system. Short term >>>you couldn't handel 1 G. Long term you die from cardiovascular, bone, >>>and immune system deterioration. >> >>Oh, I didn't know that it was that serious. But I assume we can adapt to >>a thirth of Earth's gravity or is that still to little? No one really knows. Its assumed you'ld have the same problems, just slower acting. >>>P.S. >>>A, I the only one who remembers to CC Dave Levin on the address list? >> >>I've never received a (personal) notice from Dave, he just left me (us?) >>in the dark and I always had to hear from some others that they had >>made contact with him. The least he could have done was send a >>(general) note telling he had no time for the SD-project anymore. >>In fact the only message I got from him was the one of December 17th. >>So in short, I'm a disappointed by Dave's performance. You have a point. Certainly droping the Newsletter functions off line for .. what is it 2-3 months now? Doesn't speak well for his enthusiasm. Then again the participation has been kind of slight in general lately. Kelly RE Kevin >>To: All >>Re: various. >> >>Bio interaction between earth and E.T. organisms. >> >>first, I believe that any viral infection is not possible, due to the >>totally arbitrary rna to protien coding system that earth biology uses. >> >>Of course all this assumes that the ET biology uses DNA/RNA Glucose >>ATP systems, but i do have sound Therodynamic/chemical reasons for >>thinking this is the -=--- Big snip ----- >> >>In short, A totally barren 1 G planent would be ideal for colonization, >>but totally boring for study. I agree. Its a topic that doesn't get talked about much, but the idea of steping out of a ship on an alien world taking a breath is really shallow. I guess we're all just used to decontaminated parks, or advanced medicines, or something. On the other hand a real alien ecology could be fantastically interesting! >>To: all >>Re: mission >> >>Ok, I think we all have come slam up against a brick wall. Sending >>1 E+09 Kg _any_ distance and coming back to rest WRT the target >>system is turning into a Herculean task. >> >>The charter says that we have remote sensing clues of a biosphere. we >>also have a public mandate for sending some people there to study it. >> >>I think perhaps it's time to either put the "Asimov" on a diet, or >>approach the problem from the other end. To put the "Asimov" on a diet, >>I'd suggest at least a thousand fold reduction in payload down to >> 1E+05 Kg I think we're more stuck than that. We haven't figured out any idea for slowing down a sail or MARS driven ship from relativistic speeds. NOt just not doing it on that scale. We haven't a handel on how to do it at all! >>I think this rules out self sustained mission, and requires a return. I >>still think we can go at 1 G, and use a MARS for the engine, but in order >>to over come the photon thrust, we're going to have to bring more >>reaction mass ( and use a slower exhaust velocity). for the return trip, >>I'd suggest scrapping the lineac entirely, and relying on photonic thrust >>for both portions of the trip. this means that some payload capacity >>will have to be devoted to maser transmitter control packages, but i >>don't see this as a real problem. the crew should be pared down to no >>more than 100 people, and the return module can totaly scrap the hab ring >>which can then be left in the target system as a stepping stone for a >>follow up crew if one is deemed desirable >>I'll follow this up with some hard numbers later,But, one thing that >>strikes me off hand is this, for reflection, p= 2E/C this is great for >>acelerating. for absorbtion, p=E/C this is a smaller amount of photonic >>thrust to overcome. so for example, a energy beam that provides 10 m/s^2 >>acceleration via light pressure only needs a 15 m/s^s deceleration from >>the engines to equal 10 m/s^2 total. and if it takes a 1000 to 1 RM to >>payload ratio, then that is the cost. and we just have to live with it. >>but once you get 100 people and a number of maser arrays in orbit around >>another star system, then sending a follow up mission is relatively easy How do you get a 1000 - 1 mass ration ship to move? Can we scale down the ship that much? We need the hab centrafuge to keep the crew alive and healthy, and that dictates about a 200 meter diameter ring. Fiting that and the systems and sypplies all in 1E+5 kg seems unlikely. (Thats the weight of the shutle orbiter. Or did you mean 1E+5 tons?) Adding in the construction equipment fort big maser arrays makes it even harder. >>the second option is to design this mission as if we had _no_ long range >>information on nearby systems, and design a small ~ 5000 Kg robot. to >>explore nearby systems, and return pictures and other information about >>every system in a 20 ly. radius. we might not have to slow down entirely, >>a .5 C flyby might work here. and perhaps a magnetic turning might >>work for some long range steering. The robots should be small and >>low-cost, so that is we lose a few, it's no biggie. then to luanch, we >>could use a particle luancher, (just like a solar sail, but you use >>charged particles and a heavier acceleration factor) and once the probes >>are up to speed, we don't bother with them again. It would seem you could get about as much info from a large teklescope array in Sol orbit, and get results now! From popserver Tue Dec 26 23:33:08 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8492" "Tue" "26" "December" "1995" "18:34:02" "-0500" "David Levine" "David@interworld.com" nil "157" "RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA28979 for ; Tue, 26 Dec 1995 15:29:43 -0800 (PST) Received: by www with Microsoft Mail id <01BAD3C0.BFD26C10@www>; Tue, 26 Dec 1995 18:34:11 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD3C0.BFE334F0" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 18:34:02 -0500 ------ =_NextPart_000_01BAD3C0.BFE334F0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable > >>>P.S. > >>>A, I the only one who remembers to CC Dave Levin on the address=20 >list? > >> > >>I've never received a (personal) notice from Dave, he just left me (u= s?)=20 > >>in the dark and I always had to hear from some others that they had=20 > >>made contact with him. The least he could have done was send a=20 > >>(general) note telling he had no time for the SD-project anymore. > >>In fact the only message I got from him was the one of December=20 >17th. > >>So in short, I'm a disappointed by Dave's performance. > > >You have a point. Certainly droping the Newsletter functions off line fo= r .. >what is it 2-3 months now? Doesn't speak well for his enthusiasm. Then= >again the participation has been kind of slight in general lately. Hmmm... Well, this is interesting, considering I thought I --have-- been keeping everyone up to date by occassionally sending out messages CCed to everyone on this private list. Of course, I only occassionally get these messages, and then only from Kelly (and sometimes Kevin). In fact, as I said earlier today, SunSITE is having some major malfunctio= ns. In the meantime, for the last month or two, I've been working at home on getting together a system whereby LIT would have it's own computer, and people here would get disk space, email accounts, etc. at LIT. If you are reading this message, please check my CC's and TO line - - if there's someone I've left out, it's because I haven't been included on any of their CC's... can someone forward my messages to them? It's interesting to note that I've been administrating four other web sites... one of them, ArchaeoSETI, has also recently been "disappointed" in my "performance". I would like everyone to remember that we are ALL volunteers in this endeavor... this includes me. LIT was meant from the first to be an entirely web-based campus. To be honest, I've never liked the idea of an email newsletter, and would have preferred some kind of web-based discussion system (and one a little more stable than the one I had originally written). However, since everyone seemed to think that email newsletters were the way to go, I've tried to keep up as best I could. All of the newsletters you have EVER received from LIT have been processed ONE AT A TIME by me with a simple filter... I couldn't even get ".forward" to work on SunSITE, so I had to feed each email into the filter program myself. Let me tell you, this is a bunch of work. Anyway, I have never ever intended to drop LIT, and I promise you I am working in almost all of my free time to rebuild LIT into what I've always wanted it to be. One of the ideas of LIT was that it would grow. I wanted it to be big. In this case, it was to have several people helping me run such things as classes and discussions. I can't do everything. When LIT returns, I will still need help. One of the things I'd like to do ASAP is find a charitable listserv that could perhaps support the discussion list. I have no idea where to start doing this. Does anyone have any ideas? RE: the last message from me being on Dec. 17th. Does anyone realize that it's the 26th today? In my book, nine days since my last message (and actually I sent something this very morning) is not exactly a very long time. Hell, the newsletters from LIT used to come out once a week, and were usually late at that. Is 9 days really an eternity all of the sudden? There is lots more I'd like to say, but I'll let it lie for now. -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD3C0.BFE334F0 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IgwXAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaABIA IgACAAIAMAEBCYABACEAAABGRDM2NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMABLBwEggAMA DgAAAMsHDAAaABIAIgALAAIAOQEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAGwAAAFJFOiBFbmdpbmVlcmluZyBOZXdzbGV0dGVyAKkJAQ2ABAACAAAAAgACAAEDkAYAYAwA ABIAAAALACMAAAAAAAsAKQAAAAAAAwAmAAAAAAADADYAAAAAAB4AcAABAAAAFwAAAEVuZ2luZWVy aW5nIE5ld3NsZXR0ZXIAAAIBcQABAAAAGwAAAAG60+hLRfZuNvc6vBHPrAgAgF8UovAAAAqeIQAD AAYQU5odMgMABxDmCgAAHgAIEAEAAABlAAAAUFNBLElUSEVPTkxZT05FV0hPUkVNRU1CRVJTVE9D Q0RBVkVMRVZJTk9OVEhFQUREUkVTU0xJU1Q/SVZFTkVWRVJSRUNFSVZFREEoUEVSU09OQUwpTk9U SUNFRlJPTURBVkUsSAAAAAADABAQBAAAAAMAERADAAAAAgEJEAEAAAC4CgAAtAoAADoVAABMWkZ1 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([nil nil nil nil nil nil nil nil nil] ["4261" "Tue" "26" "December" "1995" "18:38:52" "-0500" "David Levine" "David@interworld.com" nil "77" "RE: RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA29240 for ; Tue, 26 Dec 1995 15:34:22 -0800 (PST) Received: by www with Microsoft Mail id <01BAD3C1.687ECFC0@www>; Tue, 26 Dec 1995 18:38:54 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD3C1.6884EA40" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 18:38:52 -0500 ------ =_NextPart_000_01BAD3C1.6884EA40 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Yes, SunSITE lost EVERYTHING. They're still trying to figure out with Sun what happened. Apparently, the last backup didn't even turn out to be a complete backup. And when they try restoring from an older backup, the machine keeps freezing up. They promise to have stuff back soon, but it might be a month old (which is not too bad for the Asimov, but really stinks for things like ArchaeoSETI, and a huge amount of stuff that others have on SunSITE). However, every few days they've been promising to have stuff back in a few days... so, I don't really know whether to believe things will be all right or not. Anyway, I have backups of various items, but not the entire site. The problem is that the site was very poorly organized, directory-wise, and several of my sites shared the same directory. The resulting mess was more megabytes than I cared to personally back up, trusting SunSITE's backup devices. You'd be surprised how big LIT alone was. Anyway, this is another reason I've been reorganizing stuff at home (this stuff I've saved) - - to give some sort of logical order to the structure, and make it easier to backup, etc. Never fear, LIT will return (and better than ever)... the question is whe= n. -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD3C1.6884EA40 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IjcXAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaABIA JgA0AAIAZgEBCYABACEAAAAwMTM3NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMAAjBwEggAMA DgAAAMsHDAAaABIAJgA2AAIAaAEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAHwAAAFJFOiBSRTogRW5naW5lZXJpbmcgTmV3c2xldHRlcgCaCgENgAQAAgAAAAIAAgABA5AG AKgGAAASAAAACwAjAAAAAAALACkAAAAAAAMAJgAAAAAAAwA2AAAAAAAeAHAAAQAAABsAAABSRTog RW5naW5lZXJpbmcgTmV3c2xldHRlcgAAAgFxAAEAAAAbAAAAAbrT6H6a9m42/Dq8Ec+sCACAXxSi 8AAAZ/myAAMABhC2td63AwAHEDUEAAAeAAgQAQAAAGUAAABZRVMsU1VOU0lURUxPU1RFVkVSWVRI SU5HVEhFWVJFU1RJTExUUllJTkdUT0ZJR1VSRU9VVFdJVEhTVU5XSEFUSEFQUEVORURBUFBBUkVO VExZLFRIRUxBU1RCQUNLVVBESUROAAAAAAMAEBAAAAAAAwAREAMAAAACAQkQAQAAAPwEAAD4BAAA DAgAAExaRnWXVusU/wAKAQ8CFQKoBesCgwBQAvIJAgBjaArAc2V0MjcGAAbDAoMyA8UCAHByQnER 4nN0ZW0CgzP3AuQHEwKDNANFEzUHbQKDtjUSzBTINgPGFMg3EsypD99mOBEMMRs+fQqAywjPCdk7 HzkxMhxgCjLHIREgWgoUMjU1AoAKgYMNsQtgbmcxMDMUUKcLChRRC/EgWQeQLAYAgHVuU0lURSAe 0AETwCBFVkVSWVRASElORy4gFkBo6GV5Jx9AIBPAAxADICh0cnkLgGcoEG8g6GZpZwhwZQqFCGAF QPkD8HRoJZIpwBGABUARgNxwcAnwCYAnEUEq0ArA8QnwdGx5JYAp8CegC2AFJkFiANBrdXAgZCBp ZG4ndAqFZXa/CfAoEAhwA6ApkiiRYieg9GEgBaBtC1ARwCegLLT5KzJuZCpRLhInUSgSCoV/H0AT wAWwKFIDUi8gLnFsbwSBLKUsBADBaAuAJ6Br3QngcAQgA1AJ4HooUjAh+wqFJ0IgE1ADcAQAJ6Ao kXcRgC4AJ7F1DdAsoyewb3sCICWAYimhKeA0ICjQaG8skS8SBGACMGgpJjMgIDooKmBpEXA40AQg bm97LrIu4WEwkAIQBcAsIkH7AJAEYHY4hB9AB0Ar4Cey/G5rNPEFsAqFKfAoUQQgHGxpNLAUsRFx ZW9TeEVUSSWAAHAwkC8waLx1Zy8RBGAlsAVAbzfQ/zeUKfAqgTtwJ1ARoAqFN0MbAiAllik1xgqF SG93XS3xciWARWIxMGYH0WT2YROwMPMnN2EvAC4RNpS/KFU3TQqFC4AvIUYmLkqAezgxJYBJLRAC IC1gPVZr/ztgB+AwsUKCLsQ/UC3xPtX/CoUD8CfxLwIn8QUQOTIFsfM7YTBDeXdGcEriN0MstOsE IEGRdgrAaQhgBCAp4H8T4CVwCoU4ojtjLDErsWn/J5JSEScUNoICYBPgOyJCI38sIlQSKcAscFGA ReEKhXAtOFByPaEFsGcAcGl6LwmAJYAtIB9AYzIheS19A/FlQFQRsEVxB0BBgm33PbFSEQQgcxGB CYA+dyehn0EgJ6BYZ1RVMfF1bD3h/yhwB4EEIFZSBGAnkQeAV9BsYnlaokIhbgqFSwBj/1sCKIIq 4BGgAiA9gzfzM7PuclHgXZMlpScEICy0CoVdDbB2OvAHkCcRWQhgJ3cwkC8BXWByE1A20TCQaOVM EWIo0CBMJeBOsQIg/1YzT8k+4VHxQsYAcEJzPVL/YPFK8Eb3H0BXtShSN5QqgvsDcCegKGfTN5Rp ogqFW/BhLgBkKSAtbcEogmf+aTdia7I4QAAgQYIe0G5Q/2AwWgELIEyUVcNiAVigKPH/QFMKhQDA P3E44WlBCJEuw/szhRHAY0RNB8BFcUYRCsDfJYBmUk5DH0AuQyhAci8AfwJATJJfcUWzRDBKkSwi cf8KUCfBQ5E7MTCyRE0K+xpS2jEZIGMN4G3ALQtGF5L7e3MAUGl56AtkFWEL8BKw83uhCiAgRDdQ LTBmQGQRvysAefUrYT9QYDB4s0UjsLc0cTNBbdBJAjAEkFdXYQ9bNn3PJTA5QHRwOi+0L3eEYC4L gHcRd4ISqi4vUS8TwGEN0C9GYH1/MS+Czx1Qgl9+Z30wSPc28QiBYHNrJ+JcESnTSeH9BbBrP1AB gEqBh40cYXtgFjdEth5hAI2wQAA5ANDhSlDr07oBAgFHAAEAAAA1AAAAYz1VUzthPSA7cD1JbnRl cldvcmxkO2w9UHJpdmF0ZSBNREItOTUxMjI2MjMzODUyWi00NAAAAABAAAcwcG5JUOvTugFAAAgw UKdlUevTugEeAD0AAQAAAAUAAABSRTogAAAAAAIBFDQBAAAAEAAAAFSUocApfxAbpYcIACsqJRdL Fw== ------ =_NextPart_000_01BAD3C1.6884EA40-- From popserver Tue Dec 26 23:38:21 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2177" "Tue" "26" "December" "1995" "18:40:42" "-0500" "David Levine" "David@interworld.com" nil "44" "RE: RE: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id PAA29339 for ; Tue, 26 Dec 1995 15:36:12 -0800 (PST) Received: by www with Microsoft Mail id <01BAD3C1.AA1E6EE0@www>; Tue, 26 Dec 1995 18:40:44 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD3C1.AA248960" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 18:40:42 -0500 ------ =_NextPart_000_01BAD3C1.AA248960 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Oh, as for my previous post - I do apologize - I've checked my archives and have also received some CCs from Steve and a few from Ric (plus one from Zenon). -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD3C1.AA248960 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+Ii0XAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaABIA KAAqAAIAXgEBCYABACEAAAAwNTM3NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMAAnBwEggAMA DgAAAMsHDAAaABIAKAAsAAIAYAEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAHwAAAFJFOiBSRTogRW5naW5lZXJpbmcgTmV3c2xldHRlcgCaCgENgAQAAgAAAAIAAgABA5AG AMADAAASAAAACwAjAAAAAAALACkAAAAAAAMAJgAAAAAAAwA2AAAAAAAeAHAAAQAAABsAAABSRTog RW5naW5lZXJpbmcgTmV3c2xldHRlcgAAAgFxAAEAAAAbAAAAAbrT6H6a9m42/Dq8Ec+sCACAXxSi 8AAAkwKzAAMABhAjM1BFAwAHEOYAAAAeAAgQAQAAAGUAAABPSCxBU0ZPUk1ZUFJFVklPVVNQT1NU LUlET0FQT0xPR0laRS1JVkVDSEVDS0VETVlBUkNISVZFU0FOREhBVkVBTFNPUkVDRUlWRURTT01F Q0NTRlJPTVNURVZFQU5EQUZFV0ZSAAAAAAMAEBAAAAAAAwAREAMAAAACAQkQAQAAABMCAAAPAgAA 1gMAAExaRnU1jbiQ/wAKAQ8CFQKoBesCgwBQAvIJAgBjaArAc2V0MjcGAAbDAoMyA8UCAHByQnER 4nN0ZW0CgzP3AuQHEwKDNANFEzUHbQKDtjUSzBTINgPGFMg3EsypD99mOBEMMRs+fQqAywjPCdk7 HzkxMhxgCjLHIREgWgoUMjU1AoAKgYMNsQtgbmcxMDMUUBcLChRRC/JjEqAgT2g4LCBhBCACEAXA bXliIBNQZXZpCGAEIHACbxPAIC0gSSBkDm8lwCcAHtBnaXpluSdCJ3YoQBFwBZBrCYDXJjIKwBFw aSigcwqFAHBvKTARgCihB0BzJ6AfQGMeZSnBKTArIAeAIENDvyXhA2EGABPQKtIqgWEl8KMH0Sxz UmljCoUoC1BvJtECIChALHNaCfACICmGLgqFCotsaTM2DfDrJHwTUG8T0GMFQAqPC5GdGlIxGSAl UDJ4LS0LRv8XkjSTAFAAoDKfC2QVYQvwrxKwNMIMMDb2RCrAaSkwzkwmkS8gMxVBcAtQLiDsYXQm sAOgRSOwOkEEkJcnQgIwBJBXBbBsZDd/CziHNvZoAkBwOi8vWnc/gC4LgDxxdzyyLikFoG0vE8Bh DdAvZH05wi89bwBQNv89jzbYSK0oQHQIgSkwdCegawMQZwMgLAED8HRoLVIFsGv7MVABgC5HkEMt HGE0gBpQC0KtHmEASlAAQAA5AAASA5Lr07oBAgFHAAEAAAA1AAAAYz1VUzthPSA7cD1JbnRlcldv cmxkO2w9UHJpdmF0ZSBNREItOTUxMjI2MjM0MDQyWi00NQAAAABAAAcwgPYkbOvTugFAAAgwsFIF k+vTugEeAD0AAQAAAAUAAABSRTogAAAAAAIBFDQBAAAAEAAAAFSUocApfxAbpYcIACsqJRcI/w== ------ =_NextPart_000_01BAD3C1.AA248960-- From popserver Wed Dec 27 01:05:49 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2448" "Tue" "26" "December" "1995" "20:06:54" "-0500" "David Levine" "David@interworld.com" nil "48" "RE: RE: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id RAA03521 for ; Tue, 26 Dec 1995 17:02:40 -0800 (PST) Received: by www with Microsoft Mail id <01BAD3CD.B831AE50@www>; Tue, 26 Dec 1995 20:07:01 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD3CD.B8394F70" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 20:06:54 -0500 ------ =_NextPart_000_01BAD3CD.B8394F70 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Okay, I've heard from SunSITE - it turns out the latest full backups they have are October 25, and they are just now starting to restore them. Bleah. They promise it won't happen again (and that we'll never lose more than a day's work in the future)... but, still.... Bleah. -- David Levine Application Engineer - InterWorld http://www.interworld.com/staff/david/ He tried to kill me with a forklift... ------ =_NextPart_000_01BAD3CD.B8394F70 Content-Type: application/ms-tnef Content-Transfer-Encoding: base64 eJ8+IgIBAQaQCAAEAAAAAAABAAEAAQeQBgAIAAAA5AQAAAAAAADoAAEFgAMADgAAAMsHDAAaABQA BgA2AAIASgEBCYABACEAAAAwRTM3NkVGNkJDM0FDRjExQUMwODAwODA1RjE0QTJGMAA3BwEggAMA DgAAAMsHDAAaABQABwABAAIAFgEBCIAHABgAAABJUE0uTWljcm9zb2Z0IE1haWwuTm90ZQAxCAEE gAEAHwAAAFJFOiBSRTogRW5naW5lZXJpbmcgTmV3c2xldHRlcgCaCgENgAQAAgAAAAIAAgABA5AG ADAEAAASAAAACwAjAAAAAAALACkAAAAAAAMAJgAAAAAAAwA2AAAAAAAeAHAAAQAAABsAAABSRTog RW5naW5lZXJpbmcgTmV3c2xldHRlcgAAAgFxAAEAAAAbAAAAAbrT6H6a9m42/Dq8Ec+sCACAXxSi 8AADlyPUAAMABhBIaKiIAwAHED4BAAAeAAgQAQAAAGUAAABPS0FZLElWRUhFQVJERlJPTVNVTlNJ VEUtSVRUVVJOU09VVFRIRUxBVEVTVEZVTExCQUNLVVBTVEhFWUhBVkVBUkVPQ1RPQkVSMjUsQU5E VEhFWUFSRUpVU1ROT1dTVEFSVElOAAAAAAMAEBAAAAAAAwAREAMAAAACAQkQAQAAAIECAAB9AgAA WwQAAExaRnVfwcud/wAKAQ8CFQKoBesCgwBQAvIJAgBjaArAc2V0MjcGAAbDAoMyA8UCAHByQnER 4nN0ZW0CgzP3AuQHEwKDNANFEzUHbQKDtjUSzBTINgPGFMg3EsypD99mOBEMMRs+fQqAywjPCdk7 HzkxMhxgCjLHIREgWgoUMjU1AoAKgYMNsQtgbmcxMDMUUBcLChRRC/JjEqAgT2sAYXksIEkndmVo IGhlCxEgA1IGAHUAblNJVEUgLSD6aQVAdAhwBjEIYCehJkAeIAtgE9ATwCaQdWxsxQqFYgDQa3Vw BCAoYTp5JjBhJhEKwCYgT2PodG9iBJAgIuAl0ABwJyaAKkMq4mp1KOFub653CoUTwArAdAuAZyew fG8gH0ATwAWwJiAoYW2gLiAgQmwmUGgvIX5UKlITUANwBAAmICeRd5kCICd0CoURgHBwCfDlKtBn C3EgKCvkKLAwwOxlJykwLPBlJhAFwB7QjzBxBGAuswORYSBkJbDMJ3MKhTDQcmsngAOgxyhiKRAn wWUpLjbAKbDvKDAl0BPAAxBsNsEvJwqF4QqLbGkzNg3wJHwwId8T0CswOMwLVRpSMRkgJVD5Osgt LQtGF5I84wBQAKD/Ou8LZBVhC/ASsD0SDDA/RmpEKqBpJoBMM3ALgGWtO2VBMbA5oGMosGkCILwg RSOwQpErcSdwSQIw5QSQVwWwbGQ/z0DXP0aCaAJAcDovL3dH0F4uC4BEwTWRRSAuBaBtti8toQ3Q LzTQQiEvRb/vAFA/T0XfPyhILsEIgSwB/S5AazdxNAAmIAPwKGA0of8CEDWwOaABgDbBS30cYTzQ FxpQSv0eYQBSoAAAAEAAOQBwtcSc99O6AQIBRwABAAAANQAAAGM9VVM7YT0gO3A9SW50ZXJXb3Js ZDtsPVByaXZhdGUgTURCLTk1MTIyNzAxMDY1NVotNDYAAAAAQAAHMMASvZz307oBQAAIMHAKF6H3 07oBHgA9AAEAAAAFAAAAUkU6IAAAAAACARQ0AQAAABAAAABUlKHAKX8QG6WHCAArKiUXgC8= ------ =_NextPart_000_01BAD3CD.B8394F70-- From popserver Wed Dec 27 18:01:26 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2712" "Wed" "27" "December" "1995" "15:39:05" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "62" "Re: David" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id GAA27111 for ; Wed, 27 Dec 1995 06:37:57 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10767 (5.67b/IDA-1.5 for ); Wed, 27 Dec 1995 15:38:57 +0100 Message-Id: <199512271438.AA10767@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: David Date: Wed, 27 Dec 1995 15:39:05 +0100 Hello David, >It's interesting to note that I've been administrating four other web >sites... one of them, ArchaeoSETI, has also recently been >"disappointed" in my "performance". I would like everyone to remember >that we are ALL volunteers in this endeavor... this includes me. True, but I still don't know why your support for SD stopped the way it did. >LIT was meant from the first to be an entirely web-based campus. >To be honest, I've never liked the idea of an email newsletter, and >would have preferred some kind of web-based discussion system >(and one a little more stable than the one I had originally written). I like the idea of a discussion system, in fact that is what we are doing for the last 2 months. At the time I didn't vote on this because I did not participate that much. A "subscribe" list would probably be very handy. >One of the ideas of LIT was that it would grow. I wanted it to be big. >In this case, it was to have several people helping me run such things >as classes and discussions. I can't do everything. When LIT >returns, I will still need help. On of my reasons for disappointment was that some long time ago I offered you some help by writing some documents and a program. You replied to me that at that time you had no time and would write back. After waiting a few weeks I send a similar letter once more. Again you replied the same. But I'm still waiting for an answer. My offer still stands... >One of the things I'd like to do ASAP is find a charitable listserv >that could perhaps support the discussion list. I have no idea where >to start doing this. Does anyone have any ideas? As far as I know this can be done at any server with form-capabilities, the thing you need to install is a auto-mailer. (I tried to do it once but got not very far.) >RE: the last message from me being on Dec. 17th. Does anyone realize >that it's the 26th today? In my book, nine days since my last message >(and actually I sent something this very morning) is not exactly >a very long time. Hell, the newsletters from LIT used to come out >once a week, and were usually late at that. Is 9 days really an >eternity all of the sudden? That message of Dec. 17th was the last and the ONLY letter I received from you, the only other trace I have found was at Nov. 10th where Kevin told that you had written him. As I wrote before I can understand that you are busy, but I can't understand that you have not 15 minutes to write a letter to people that try to build something together with you. > >Attachment Converted: D:\REEngin1 > What is this attachment? All letters from you seem to include it, but when I take a look at it, it is garbled completely. Timothy From popserver Wed Dec 27 18:01:28 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5100" "Wed" "27" "December" "1995" "15:39:12" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "95" "Re: Kelly" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id GAA27117 for ; Wed, 27 Dec 1995 06:38:06 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10773 (5.67b/IDA-1.5 for ); Wed, 27 Dec 1995 15:39:06 +0100 Message-Id: <199512271439.AA10773@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Kelly Date: Wed, 27 Dec 1995 15:39:12 +0100 Timothy replies to Kelly > >>After rethinking it, I see what you mean. > >>The only thing I'm not sure about is what the physics of plasma reflection > >>are. We may reflect radio-waves to the ionosphere everyday but how does it > >>work? And does it work in the Asimov also? > >It would certainly involve a much larger scale, and I don't know what the >reflection efficency is. Or how much mass would need to be ionized to keep >up the reflection. One thing for certain, the stuff will be HOT! I think it is that HOT thing that worries me, it may well be that that will screw up your whole nice reflection. >That would be true if all major areas of research were being investigated and >resonably well funded. But most areas of fusion research that I know of have >no funding. Magnetic plasma fusion is geting funded, but at least in the US >the systems are dead ends. Even if they worked they'ld be useless (to large >to be intergrated into the power grid.). Where as more inovative designs >that are considered more promising (like Bussards among others) are geting no >funding. You can't assume that more money is used for this, because I could assume that more money is used for research for anti-matter containment and creation. Both fusion and anti-matter are areas where little is known about. >Oh yeah, the single stage to orbit program (SSTO). My excorperation, and the >NASA department I used to work at in NASA headquarters were working on that >program. Increadable potential. It could cut costs to orbit by a factor of >100! Fed Ex is even rumored to be seriously interested in using them for >suborbital intercontenental mail carriers. E-mail is cheaper and faster :) >I'ld debate that. Since your stuck in an artificial habitat anyway, one in >space has easy access to all the floating ores and raw materials in the solar >system. Much of which would be hard to get at on a planet (ever see a strip >mine) and much harder to transport. I'm a firm beleaver that heavy industry >will largely move off earth in a century or two. If your already off planet >and in a starship, trying to set up on a planet would be hellish. Hmm, yeps, you may well be right. But the place where people want to live will be on a nice planet. Doing research on a planet or building industries is still much more interesting than flying back to Earth. And if it isn't more intersting, then research will gives more fruits for the money than flying back would do. >People won't see it right away, but they will know people are out there. I >think that would be enough to get public interest. I know public interest in >robot probes is near nill. As NASA constantly found. Robots were thought of >as scout craft for maned expiditions. If no manned folowups were planed (and >frequently mentioned) public interest in funding the robots droped way off. > Generally a so what atitude. Drove the Robot probe teams CRAZY! I think that the mission will not be funded by governments but by commercial firms. They would use it as advertisement and gain of new technology. Such a project will not be done by one country, but by all developped countries. So the competition between countries would not be the same as they were in past times. So public interest should have a completely other background: love for the unknown. Ordinary people probably are more concerned about other things. > >>So where to and when is our new goal? Until now only fusion may bring > >>us out of the solar system within reasonable time. Even if you use a > >>beam, the fusion is necessary to maintain the beam. > >Well you could power the beam with big solar electric power platforms in >space. (The kind of stuff the L-5 socyety kept proposing to power earth.) No, Earth's consumption of electricity is much much less than that of the Asimov. As I showed before you would need an array bigger than the moon! And than you only have the energy but not the beam. For that you need again an enormous array of high power masers. >I would definatly prefer a dead world as a possible colony site over a lush >one like earth. Wouldn't be as interesting to study, but much more >survivable. The problem is any world that could support us, probably has >life. So how do we solve that? Walking in spacesuits all day isn't that much fun. >Hell, we're still trying to find cures for all the plagues on earth. So far >our best luck seem to be in destroying the worst sections of the ecology >(draining wetlands, fogging everything with pestasides, etc..) and building >urban semi-ecologies. Most of the habited areas of the developed world >(europe, North America, etc..) do this so routinely we don't even notice >anymore. But then living in a coutry thats largly under sea level I hardly >have to tell you. ;) The place I live is save, even if all the polar ice melts away. :) (33 metres above sealevel) What you write may be true, but is not complete, we have found cures for many diseases and our understanding gets better all the time. In 50 years this will only be better and more advanced. Timothy From popserver Wed Dec 27 18:01:31 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2790" "Wed" "27" "December" "1995" "15:39:21" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "53" "Re: Kevin" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id GAA27122 for ; Wed, 27 Dec 1995 06:38:14 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10782 (5.67b/IDA-1.5 for ); Wed, 27 Dec 1995 15:39:15 +0100 Message-Id: <199512271439.AA10782@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Kevin Date: Wed, 27 Dec 1995 15:39:21 +0100 ReplyTo: Kevin Subject: Bio interaction between earth and E.T. organisms. >this is not to say that a alien ecosystem would be totally useless to >us. who know what wonders we may find. how bout an organism that can >"grow" silicon chips? of solar cells? perhaps some organism lives in a >metal rich environment and can really concentrate metal ores. Perhaps, >perhaps, perhaps. I could go on all day, how bout a critter that _likes_ >70 % ethanol (I'll bet that many companies would love to make brandy >without having to distill) bacteria that excrete oil, or plastic, or ones >that prefer it as a food source. the list goes on and on, and I'm very >willing to bet that none of these creatures will be the first exploitable >alien lifeform. and I'd further bet that the universe is not only >stranger than I imagined, it's stranger than i _can_ imagine. It seems that some of that kind of bacteria also live on earth, every week new ones are discovered. Solar cells are a bit to complex to be produced by bacteria and I think they won't produce pure silicium bars either. So maybe you imagined a bit too much. What bacteria are best at is converting molecules (not atoms). But you shouldn't forget that we are getting better and better in doing the same thing with technology. >In short, A totally barren 1 G planent would be ideal for colonization, >but totally boring for study. That means we need two planets :) Subject: mission >I think perhaps it's time to either put the "Asimov" on a diet, or >approach the problem from the other end. To put the "Asimov" on a diet, >I'd suggest at least a thousand fold reduction in payload down to 1E+05 Kg >I think this rules out self sustained mission, and requires a return. I >still think we can go at 1 G, and use a MARS for the engine, but in order >to over come the photon thrust, we're going to have to bring more >reaction mass ( and use a slower exhaust velocity). for the return trip, >I'd suggest scrapping the lineac entirely, and relying on photonic thrust >for both portions of the trip. this means that some payload capacity >will have to be devoted to maser transmitter control packages, but i >don't see this as a real problem. the crew should be pared down to no >more than 100 people, and the return module can totaly scrap the hab ring >which can then be left in the target system as a stepping stone for a >follow up crew if one is deemed desirable As Kelly said, 1E5 is too small, probably the engines alone would weigh that much. Also such "maser transmitter control packages" as you call them so neatly won't be thato small, you are talking about an array of several square kilometres filled with masers and powerstations. (See also my letter to Kelly at Dec. 23th) Timothy From popserver Wed Dec 27 18:01:46 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11958" "Wed" "27" "December" "1995" "10:30:27" "-0500" "David Levine" "David@interworld.com" nil "214" "RE: David" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: David@InterWorld.com Received: from www (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id HAA28461 for ; Wed, 27 Dec 1995 07:25:59 -0800 (PST) Received: by www with Microsoft Mail id <01BAD446.5C2BE610@www>; Wed, 27 Dec 1995 10:30:36 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BAD446.5C45D6B0" From: David Levine To: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "KellySt@aol.com" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" To: "'Timothy van der Linden'" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: David Date: Wed, 27 Dec 1995 10:30:27 -0500 ------ =_NextPart_000_01BAD446.5C45D6B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit >True, but I still don't know why your support for SD stopped the way it >did. As I've said, I don't really think my support has ever stopped. The newsletters fell apart at my end, mainly because the file containing the email addresses got corrupted. Yes, it could have been rebuilt, but there were absolutely hundreds of people involved... Anyway, I certainly had never intended (and still don't intend) that the official newsletters are dead. It WILL return. >>LIT was meant from the first to be an entirely web-based campus. >>To be honest, I've never liked the idea of an email newsletter, and >>would have preferred some kind of web-based discussion system >>(and one a little more stable than the one I had originally written). > >I like the idea of a discussion system, in fact that is what we are doing >for the last 2 months. At the time I didn't vote on this because I did not >participate that much. A "subscribe" list would probably be very handy. Actually, perhaps I didn't explain myself well... when I say a "web-based discussion system" I mean one that works entirely though the WWW, and does not include email in any way. You would post using forms, and read the discussion on a series of pages. However, I think the majority of the most active people seem to prefer an email discussion list. >On of my reasons for disappointment was that some long time ago I >offered >you some help by writing some documents and a program. You replied >to me >that at that time you had no time and would write back. After waiting a >few >weeks I send a similar letter once more. Again you replied the same. But >I'm >still waiting for an answer. >My offer still stands... Just so you know, my response right now to such an offer would be "please, go ahead, write something and let me know when you have finished". This is how I responded to several people who wished to write articles for LIT (i.e. Ges Seger, Jack Sarfatti come to mind... there are a few others who have contributed that I can't remember off-hand at the moment) in the past... If you made an offer to which I said "I don't have the time at the moment" in response, I can only assume that your offer was not of the "I have an idea for an article I'd like to write" variety, but rather a "what can I do to help?" offer.... my response to the latter would STILL be "I'll have to get back to you, I don't have the time right now", mainly because I don't have the time to figure out who should be writing what, when, and how. I always accept anything you'd want to put on the pages. When SunSITE gets its act together again, I'll do a quick survey for you, and I think you'll find that at least a third of the starship school pages are not by me... and ALL of them were pages people just sent me, saying "here, can you use this?" So, please, if you want to do something (and this is to everyone), please do it. When LIT is back, it can continue to grow in the way it has in the past. >>One of the things I'd like to do ASAP is find a charitable listserv >>that could perhaps support the discussion list. I have no idea where >>to start doing this. Does anyone have any ideas? > >As far as I know this can be done at any server with form-capabilities, the >thing you need to install is a auto-mailer. (I tried to do it once but got >not very far.) I think we're talking at cross-purposes again. I'm looking for a listserv at some site somewhere that is charitable enough to start a new discussion list (I have heard that many listservs will do this - I just don't know how to go about doing it) for us... it would make things very simple, and very automatic. >That message of Dec. 17th was the last and the ONLY letter I received >from >you, the only other trace I have found was at Nov. 10th where Kevin told >that you had written him. > >As I wrote before I can understand that you are busy, but I can't >understand >that you have not 15 minutes to write a letter to people that try to build >something together with you. Um, I've looked through my archive of the current batch of "newsletters", extending back to November 5th (again, a majority of these come from Kelly), and find... um... let's see... zero from Tim, out of fifty nine messages since then. When I respond to this list (and granted it's not often... but to be honest, most of this discussion is out of my technical depth, and I've rarely participated in the project since it's beginnings over a year ago anyway, even when it was five newsletters once a week) it's reply-to-all.... if you're not getting them, I can only assume you're not getting the letters I'm responding to anyway. Actually, I have a bad feeling now that apparently with my 59 messages, I'm still missing quite a number. Sigh. >> >>Attachment Converted: D:\REEngin1 >> > >What is this attachment? All letters from you seem to include it, but >when I >take a look at it, it is garbled completely. > >Timothy On this front, I'm sorry, I don't know. Certainly I'm not attaching anything to my documents. We're using Microsoft Exchange at work, which every time it starts reminds me its a Beta, sooooo.... Also, some people tell me that some of my letters include odd characters (=20, or something) at the end of each line... Also something I don't see when I'm typing messages. 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NAA21077 for ; Wed, 27 Dec 1995 13:41:42 -0800 (PST) Received: from sea-ts3-p47.wolfenet.com (sea-ts3-p47.wolfenet.com [204.157.98.229]) by wolfe.net (8.7.3/8.7) with SMTP id NAA08002; Wed, 27 Dec 1995 13:43:13 -0800 (PST) Message-Id: <199512272143.NAA08002@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Wed, 27 Dec 1995 13:43:13 -0800 (PST) >ReplyTo : Ric > >>In system travel should give us a good idea of how well people adapt to >>space travel. A few missions of longer and longer duration to near and then >>farther planets would help to see the adaptiveness of humans to prolonged >>space flight. By the time we sent some folks to Titan and back we could >>refine the problem and work on means to sidestep these. > >Yes, that will give us a preview. But I think you don't have to wait for >that: Imagine living and working in your own house, never allowed to open >the door and go outside. When looking outside nothing happens, the stars >almost don't change. How would you feel? >How many people are there that can survive happely and healty in such an >environment? >Probably an important feature of the spacevessel would be that it feeled >much like Earth's environment. This doesn't mean it should look the same, >but several things like a leisure room, a bar, a garden of some sort (and >maybe a swimming pool) also crew quarters should not be too small. In fact >all kinds of things that would make the spaceship bigger and heavier would >make living better. >So the dilemmas are size and weight versus crew happyness and healthyness. >The point is to make a spacevessel that feels like YOUR environment (home, >work, shops). Ric replies: This is about like what I was saying many, many months ago. It wouldn't be much different than life in a submarine. The spaces would be larger. The number of people would be many more. There would be windows where as a submarine doesn't. The only limiting factor for subs is the food issue. ( Take it with us or grow it along the way, eother one ) Humans are a pretty addaptable animal. Look at how many different localities they inhabit on this earth. The room to move about and jobs to do and time and places to relax are importent to the mission. The Mir and Space Shuttle are OK for short periods of time. For years and years you can't have enough space and room. Hab modules with different "landscapes" and " cultures" would help relieve boredom. >>We are going to have to establish a solarsystem based society before we >>would be able to convince anyone of the need to go anywhere else. > >So if we want to continue the SD project we should make it 2140 instead of 2040. Very possibly The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Wed Dec 27 21:52:50 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["671" "Wed" "27" "December" "1995" "13:54:05" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "19" "Re: possible LIT site." "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.2/8.7.2) with ESMTP id NAA21435 for ; Wed, 27 Dec 1995 13:47:40 -0800 (PST) Received: from sea-ts3-p47.wolfenet.com (sea-ts3-p47.wolfenet.com [204.157.98.229]) by wolfe.net (8.7.3/8.7) with SMTP id NAA08533; Wed, 27 Dec 1995 13:54:05 -0800 (PST) Message-Id: <199512272154.NAA08533@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: Kevin C Houston Cc: "David Levine \"jim@bogie2.bio.purdue.edu\"" , "'KellySt@aol.com'" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: Re: possible LIT site. Date: Wed, 27 Dec 1995 13:54:05 -0800 (PST) I would be willing to part with $20.00 (US) per year to see this >continue. >I've seen quotes in various magazines from $30 (US) for 10 MB on up. I >would think that for as little as $100 a year, we could have a very nice >website with lots and lots of room. Counting heads that i see here >often, (no pressure, I'm just thinking out loud) me, Dave, Kelly, Ric, >Timothy, Steve. That's 6 people who contribute regularly, would bring >the price down to $16.67 each. the more people who help, the less each >of us would have to pay. Count me in for a $20.00 bill. The rest of you all in?? Ric The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Wed Dec 27 22:03:11 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3987" "Wed" "27" "December" "1995" "23:02:01" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "71" "RE: David" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.2/8.7.2) with SMTP id OAA22119 for ; Wed, 27 Dec 1995 14:01:07 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA21112 (5.67b/IDA-1.5 for ); Wed, 27 Dec 1995 23:01:56 +0100 Message-Id: <199512272201.AA21112@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: RE: David Date: Wed, 27 Dec 1995 23:02:01 +0100 ReplyTo: David >>I like the idea of a discussion system, in fact that is what we are doing >>for the last 2 months. At the time I didn't vote on this because I did not >>participate that much. A "subscribe" list would probably be very handy. > >Actually, perhaps I didn't explain myself well... when I say a "web-based >discussion system" I mean one that works entirely though the WWW, and >does not include email in any way. You would post using forms, and >read the discussion on a series of pages. However, I think the majority >of the most active people seem to prefer an email discussion list. What is the real difference? If you have a mail-adress, you can forward all mail to a single file. (maybe change the filename every week) That file could be made visible in a web page. This of course is the most crude method, but it will work. (this way all mail-headers are included of course) Having to fill out forms takes a while, even if you copy it directly from a pre-written text into the form. For people with limited (dialup) access it is much more handy to send a single mail. Also downloading several pages is less convenient than just getting your mail. >Just so you know, my response right now to such an offer would be >"please, go ahead, write something and let me know when you have >finished". This is how I responded to several people who wished to >write articles for LIT (i.e. Ges Seger, Jack Sarfatti come to mind... >there are a few others who have contributed that I can't remember >off-hand at the moment) in the past... If you made an offer to which >I said "I don't have the time at the moment" in response, I can >only assume that your offer was not of the "I have an idea for an >article I'd like to write" variety, but rather a "what can I do to help?" >offer.... my response to the latter would STILL be "I'll have to get >back to you, I don't have the time right now", mainly because I >don't have the time to figure out who should be writing what, when, >and how. I always accept anything you'd want to put on the pages. >When SunSITE gets its act together again, I'll do a quick survey >for you, and I think you'll find that at least a third of the starship >school pages are not by me... and ALL of them were pages people >just sent me, saying "here, can you use this?" So, please, if >you want to do something (and this is to everyone), please do it. >When LIT is back, it can continue to grow in the way it has in the >past. In fact you had already some subjects (shown on some webpage), I asked you if you could tell me what the exact purpose was, because some of the subjects were quite broad. It would have been better if you had responded: "Just write, and I will put it on the web" instead you indeed wrote "I'll have to get back to you, I don't have the time right now". Also I said I had a Pascal-program that could do some calculations, I don't know what your answer was, but it wasn't "send it to me". >>As I wrote before I can understand that you are busy, but I can't >>understand >>that you have not 15 minutes to write a letter to people that try to build >>something together with you. > >Um, I've looked through my archive of the current batch of "newsletters", >extending back to November 5th (again, a majority of these come from >Kelly), and find... um... let's see... zero from Tim, out of fifty nine >messages since then. When I respond to this list (and granted it's >not often... but to be honest, most of this discussion is out of my >technical depth, and I've rarely participated in the project since it's >beginnings over a year ago anyway, even when it was five newsletters >once a week) it's reply-to-all.... if you're not getting them, I can only >assume you're not getting the letters I'm responding to anyway. >Actually, I have a bad feeling now that apparently with my 59 messages, >I'm still missing quite a number. Sigh. There are about 140 of them, I have all letters since contact was "lost". Timothy From popserver Sat Dec 30 04:58:29 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8226" "Fri" "29" "December" "1995" "21:53:43" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "201" "Re: RE: Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA05669 for ; Fri, 29 Dec 1995 18:53:45 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id VAA29778; Fri, 29 Dec 1995 21:53:43 -0500 Message-ID: <951229215342_80862787@mail06.mail.aol.com> From: KellySt@aol.com To: David@interworld.com, hous0042@maroon.tc.umn.edu, jim@bogie2.bio.purdue.edu, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: RE: Engineering Newsletter Date: Fri, 29 Dec 1995 21:53:43 -0500 Sunsite didn't have a good backup since OCTOBER!! I'm glad were not paying them, at least were getting our moneys worth out of them. Dave, whats ArchaeoSETI? RE: Timothy replies to Kelly > > > >>After rethinking it, I see what you mean. > > >>The only thing I'm not sure about is what the physics of plasma reflection > > >>are. We may reflect radio-waves to the ionosphere everyday but how does it > > >>work? And does it work in the Asimov also? > > > >It would certainly involve a much larger scale, and I don't know what the > >reflection efficency is. Or how much mass would need to be ionized to keep > >up the reflection. One thing for certain, the stuff will be HOT! > > I think it is that HOT thing that worries me, it may well be that that > will screw up your whole nice reflection. Hot would be good for the reflection. It would meen it was more ionized. Also it would be more presure for drive purposes. Might be a little hard on the hull thou. ;) > >That would be true if all major areas of research were being investigated and > >resonably well funded. But most areas of fusion research that I know of have > >no funding. Magnetic plasma fusion is geting funded, but at least in the US > >the systems are dead ends. Even if they worked they'ld be useless (to large > >to be intergrated into the power grid.). Where as more inovative designs > >that are considered more promising (like Bussards among others) are geting no > >funding. > > You can't assume that more money is used for this, because I could assume > that more money is used for research for anti-matter containment and > creation. Both fusion and anti-matter are areas where little is known about. I wasn't refering to LIT assumptions, only real world. But, if we are to assume a large scale space infastructure. I guess we can assume it was worth there while to develope fusion systems. > >Oh yeah, the single stage to orbit program (SSTO). My excorperation, and the > >NASA department I used to work at in NASA headquarters were working on that > >program. Increadable potential. It could cut costs to orbit by a factor of > >100! Fed Ex is even rumored to be seriously interested in using them for > >suborbital intercontenental mail carriers. > > E-mail is cheaper and faster :) A but its so hard to E-mail a xmas present! ;) > >I'ld debate that. Since your stuck in an artificial habitat anyway, one in > >space has easy access to all the floating ores and raw materials in the solar > >system. Much of which would be hard to get at on a planet (ever see a strip > >mine) and much harder to transport. I'm a firm beleaver that heavy industry > >will largely move off earth in a century or two. If your already off planet > >and in a starship, trying to set up on a planet would be hellish. > > Hmm, yeps, you may well be right. But the place where people want to live > will be on a nice planet. Hey, if they want a nice planet their going to be out of luck on out flight. We'll only be ofering dead, or plague worlds. > Doing research on a planet or building industries is still much more > interesting than flying back to Earth. And if it isn't more intersting, then > research will gives more fruits for the money than flying back would do. Building industries? I don't follow. Research I can understand, but obviously they can't do that forever. Nor do I expect to settle for living out the rest of their lives in the hab deck. > >People won't see it right away, but they will know people are out there. > > I think that would be enough to get public interest. I know public interest in > >robot probes is near nill. As NASA constantly found. Robots were thought of > >as scout craft for maned expiditions. If no manned folowups were planed (and > >frequently mentioned) public interest in funding the robots droped way off. > > Generally a so what atitude. Drove the Robot probe teams CRAZY! > > I think that the mission will not be funded by governments but by commercial > firms. They would use it as advertisement and gain of new technology. Such a > project will not be done by one country, but by all developped countries. So > the competition between countries would not be the same as they were in past > times. So public interest should have a completely other background: love > for the unknown. Ordinary people probably are more concerned about other things. I can't see corporations droping probably hundreds of billions of dollars on a project like this. It absolutly would have no short term benifit (decades at least) and advertizing would supply this kind of money. International projects ARE A DISSASTER!! I was in the International Space Station Freedom Program, and can assure you it convinced about everybody that international cost everyone far more, slowed the program WAY down, and generally made it impossible. If a project like this requirers international particip[ation, it will be a write off. > > > >>So where to and when is our new goal? Until now only fusion may bring > > >>us out of the solar system within reasonable time. Even if you use a > > >>beam, the fusion is necessary to maintain the beam. > > > >Well you could power the beam with big solar electric power platforms in > >space. (The kind of stuff the L-5 socyety kept proposing to power earth.) > > No, Earth's consumption of electricity is much much less than that of the > Asimov. As I showed before you would need an array bigger than the moon! And > than you only have the energy but not the beam. For that you need again an > enormous array of high power masers. I don't remember you mentioning that. In any event its the cost not the size that would make a difference. > > >I would definatly prefer a dead world as a possible colony site over a lush > >one like earth. Wouldn't be as interesting to study, but much more > >survivable. The problem is any world that could support us, probably has > >life. > > So how do we solve that? Walking in spacesuits all day isn't that much fun. Exploration is seldom a lot of fun. I can't think of anyway to solve the biohazard problem other than space suits, or staying in the ship and using tele-operated robots. > >Hell, we're still trying to find cures for all the plagues on earth. So far > >our best luck seem to be in destroying the worst sections of the ecology > >(draining wetlands, fogging everything with pestasides, etc..) and building > >urban semi-ecologies. Most of the habited areas of the developed world > >(europe, North America, etc..) do this so routinely we don't even notice > >anymore. But then living in a coutry thats largly under sea level I hardly > >have to tell you. ;) > > The place I live is save, even if all the polar ice melts away. :) (33 > metres above sealevel) > What you write may be true, but is not complete, we have found cures for > many diseases and our understanding gets better all the time. In 50 years > this will only be better and more advanced. True, but its taken us centuries to get this far in our medical skills. We won't have centuries, or even decades, to learn how to fight the alien bio-hazards. > >ReplyTo : Ric > >>We are going to have to establish a solarsystem based society before > >>we would be able to convince anyone of the need to go anywhere else. > > > >So if we want to continue the SD project we should make it 2140 instead of > 2040. > > Very possibly > If we shove the calendar to 2140 from 2050, we'ld have nothing to base it on. We would have to debate what type of physics, much less engineering we could assume. Oh, what did.. whoever said it (I never got the origional message) mean by: > >>We are going to have to establish a solarsystem based society before > >>we would be able to convince anyone of the need to go anywhere else. We obviously arn't going to NEED to go to another star system, and certainly we've never come up with a reason anyone would want to stay in this other starsystem. (Trade obviously isn't practical with the technology we're discusing.) But that doesn't meen people wouldn't be interested in finding out what is there. Kelly P.S. I suppose I'ld kick in $20 for the cause if it would help. From popserver Sun Dec 31 01:59:18 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6198" "Sat" "30" "December" "1995" "22:07:00" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "130" "Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA07583 for ; Sat, 30 Dec 1995 13:05:55 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA16549 (5.67b/IDA-1.5 for ); Sat, 30 Dec 1995 22:06:56 +0100 Message-Id: <199512302106.AA16549@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Engineering Newsletter Date: Sat, 30 Dec 1995 22:07:00 +0100 Timothy replies to Kelly: >>You can't assume that more money is used for this, because I could assume >>that more money is used for research for anti-matter containment and >>creation. Both fusion and anti-matter are areas where little is known >>about. > >I wasn't refering to LIT assumptions, only real world. But, if we are to >assume a large scale space infastructure. I guess we can assume it was worth >there while to develope fusion systems. Indeed, but so would anti-matter systems after a while. >>Doing research on a planet or building industries is still much more >>interesting than flying back to Earth. And if it isn't more intersting, then >>research will gives more fruits for the money than flying back would do. > >Building industries? I don't follow. For some kind of colonization. Even if it is used as "refresh" point for futere missions to other solarsystems, it needs some form of selfsufficiency. Therefor it needs "farms" and buildings, you can't make them all by hand, so you need some form of small industry. >Research I can understand, but obviously they can't do that forever. Why not, there will be plenty to figure out. >Nor do I expect to settle for living out the rest of their lives in the hab >deck. Why don't you expect them to do that? I still don't see that as suicide, they can live perfectly healthy lives. >I can't see corporations droping probably hundreds of billions of dollars on >a project like this. It absolutly would have no short term benifit (decades >at least) and advertizing would supply this kind of money. One Japanese building company is seriously thinking about how it could build on the moon. Now it may be a sign of advancement(=adverticement) but in 20 years they may be the first(=money) to build there. Indeed one company would not have enough money, but one company alone could not build a city, so several companies will take their share. And after all, the government's money is in fact the money of the companies. >International projects ARE A DISSASTER!! I was in the International Space >Station Freedom Program, and can assure you it convinced about everybody that >international cost everyone far more, slowed the program WAY down, and >generally made it impossible. If a project like this requirers international >particip[ation, it will be a write off. May be, but a single country couldn't do it either. I don't know all about problems about Freedom, but wasn't NASA the main "sponsor"? Such a project would be a challenge for mankind, it would not ALLOW us to work together, it would INSIST us working together. Maybe today such a project will not work, but countries are aligning. I know this sound biblical: "When all sheep listen to one herdsman...", but I think it's better than that: "The sum of the parts is much more than the parts themselves". >>No, Earth's consumption of electricity is much much less than that of the >>Asimov. As I showed before you would need an array bigger than the moon! >>And than you only have the energy but not the beam. For that you need again >>an enormous array of high power masers. > >I don't remember you mentioning that. In any event its the cost not the size >that would make a difference. Size is a problem of feasability. If things get too big, it takes also more time to build them. An array of thousands or even a million square kilometres is not possible to build in a reasonable time. >> So how do we solve that? Walking in spacesuits all day isn't that much fun. > >Exploration is seldom a lot of fun. I can't think of anyway to solve the >biohazard problem other than space suits, or staying in the ship and using >tele-operated robots. Exploration isn't much fun? What else drives people to such far places... >> The place I live is save, even if all the polar ice melts away. :) (33 >> metres above sealevel) >> What you write may be true, but is not complete, we have found cures for >> many diseases and our understanding gets better all the time. In 50 years >> this will only be better and more advanced. > >True, but its taken us centuries to get this far in our medical skills. We >won't have centuries, or even decades, to learn how to fight the alien >bio-hazards. In all these centuries we accumulated these skills, a lot of these skills can be used as general solutions and not as specific solutions. Often if a cure for one disease is found, a lot of similar diseases are cured too. It is not the specific case that takes decades to develop but the general solution. So since we want to know what is out there, we will study those creatures that have the potential to make us ill. Probably that is enough to find a specific cure. >>>So if we want to continue the SD project we should make it 2140 instead of >>>2040. >> >> Very possibly > >If we shove the calendar to 2140 from 2050, we'ld have nothing to base it on. > We would have to debate what type of physics, much less engineering we could >assume. So, what should we do? The main problem is the source of power that we are allowed to use. So before we start discussing how the engine looks, we should know what techniques we can use and in what AMOUNT. Just saying that money doesn't matter isn't enough, money means manpower. Whatever the futere will bring, the amount of capable manpower will be limited. >We obviously arn't going to NEED to go to another star system, and certainly >we've never come up with a reason anyone would want to stay in this other >starsystem. (Trade obviously isn't practical with the technology we're >discusing.) But that doesn't meen people wouldn't be interested in finding >out what is there. It could be a goal for better survival of the human species. Two so separate worlds are unlikely to become extinct at the same time. The reason for people to stay in such a desolated area is quite obvious, to start a new or other life. Think of the people that went to Australia the last 50 years (not the prisoners), a lot of them wanted new chances. Chances they could not realize at their previous home. My guess is that there are millions of people that want to get away from their present life and start somewhere else. Timothy From popserver Sun Dec 31 11:43:39 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["906" "Sun" "31" "December" "1995" "03:38:27" "-0800" "Steve VanDevender" "stevev@efn.org" nil "19" "Engineering Newsletter" "^From:" nil nil "12" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id DAA03559; Sun, 31 Dec 1995 03:37:23 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id DAA19347; Sun, 31 Dec 1995 03:38:27 -0800 Message-Id: <199512311138.DAA19347@tzadkiel.efn.org> In-Reply-To: <199512302106.AA16549@student.utwente.nl> References: <199512302106.AA16549@student.utwente.nl> From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Engineering Newsletter Date: Sun, 31 Dec 1995 03:38:27 -0800 This page is _so cool_ that I've stayed up until 3:30 am looking at it: http://www.fourmilab.ch/cship/cship.html Although his starship design is simplistic and intended more for expository purposes than as a completely realistic design, it does have some interesting features I haven't seen us discuss before. In particular he discusses the need for streamlining (!) for a ship that travels at high relativistic speeds. In essence it's a self-powered ship fueled by antimatter. The coolest part, though, is a couple of MPEGs that show trips through his imaginary "lattice galaxy" at relativistic speeds. This is exactly the kind of thing I want to do with my starship simulation program (still completely embryonic at this point), but with a database of real stars in the Solar neighborhood. View the MPEGs, and then we can talk about why it looks like you're flying backwards at the start of a trip. From popserver Wed Nov 29 07:08:42 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5582" "Tue" "28" "November" "1995" "23:07:53" "-0800" "Steve VanDevender" "stevev@efn.org" nil "109" "Re: Summarry of the momentum wars and idea." "^From:" "KellySt@aol.com, stevev@efn.org, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "KellySt@aol.com, stevev@efn.org, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "11" nil nil nil nil] nil) Received: from tzadkiel.efn.org by efn.efn.org (4.1/smail2.5/05-07-92) id AA05662; Tue, 28 Nov 95 23:04:17 PST Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.1/8.7.1) id XAA00455; Tue, 28 Nov 1995 23:07:53 -0800 Message-Id: <199511290707.XAA00455@tzadkiel.efn.org> In-Reply-To: <951128203350_119181713@emout06.mail.aol.com> References: <951128203350_119181713@emout06.mail.aol.com> X-UIDL: 817628697.000 From: Steve VanDevender To: KellySt@aol.com Cc: stevev@efn.org, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Summarry of the momentum wars and idea. Date: Tue, 28 Nov 1995 23:07:53 -0800 KellySt@aol.com writes: > >> Besides not treating momentum as a vector quantity, people are > >> making the mistake of thinking that lateral loading of the sail > >> assembly is a magical sink for momentum or energy. The error is > >> in thinking that stress on a static structure absorbs energy or > >> momentum continuously over time. If the sail does not move > >> relative to the ship, then it cannot absorb or dissipate momentum > >> separately from the ship. It cannot absorb momentum if it does > >> not move, because momentum means motion. ---- > > (??!) > Thats like the old argument that if a tractor is pushing against a wall its > doing no work, since the wall isn't accelerated. The sail is getting a > thrust that is perpendicular to the surface of reflection. If you want to > describe the portion of the thrust that isn't accelerating the ship as > invalid, enjoy. The tractor is dissipating energy because it contains moving parts in its engine and drive train that keep moving even though the tractor chassis and the wall are not. And it did do some amount of work compressing itself against the wall; when the engine is turned off, the tractor will roll away from the wall. Lean a board against the wall. Does it dissipate energy because it can't move the wall? Lean a heavy iron bar against the wall. Does it dissipate more energy than the board? Are the bricks at the bottom of the wall permanently warmer than the bricks at the top because they are under compression? These are all what I mean by static stress. Static stress does not dissipate energy. Varying stress dissipates energy; the tractor engine powered by intermittent gasoline explosions produces vibration and heat as it pushes the tractor against the wall; the tractor vibrating against the wall even heats the wall. On the other hand, the board or the iron bar, or the bricks at the bottom of the wall, do not dissipate energy. If you think they do, tell me where it comes from. You can't claim that gravity is continuously pumping energy into the objects; you can't gain or lose energy if you don't move up or down in a gravity field. > But when you start to mutter things like: > >> ---as long as the sail does not fall apart or the support > >> members do not break, no more energy is dissipated into > >> loading of the sail structure. > > We have a problem. > > A considerable amount of energy will be continuously loaded and (hopefully) > disapated by the sail cross webbing. If we don't consider it, and make sure > the structure can disapate it, the cross cables will melt under the energy > they have to disapate under this lateral thrust load. The structure will dissipate energy if the photon beam varies periodically with time, as the up-and-down variations will induce vibration in the structure. This is certainly a real engineering problem that would have to be considered in a real ship. My intention was to prove that Kevin's parasail design couldn't absorb photons without absorbing their momentum. This principle is still true even if the parasail isn't exposed to a completely steady, unvarying photon flux. The members of the support structure don't "dissipate" or "absorb" forward momentum because they are under sideways load. You seem to have a real misunderstanding of the difference between work and potential. When you put a structure under tension or compression, you do change its energy, ONCE, when you slightly pull apart or scrunch together all of the atomic bonds in the object; you have put potential energy into the object. As long as the forces on the structure do not change, no further energy flows in or out of it; it does not continue to dissipate energy with time. Your house does not radiate heat because it is in a gravity field. The cornerstone of the Empire State Building is not hot because it is holding up the weight of the building. The Earth is not losing energy to everything that its gravity holds to the ground. Just as I could build a reactionless drive from Kevin's parasail, if I play by your rules I can build a perpetual motion machine from a piece of metal in a vise; all I have to do is extract the energy that you claim it will continually radiate for as long as it is in the vise. The reason that real engineering structures dissipate energy is that there is rarely such a thing as pure static stress. Structures endure varying loads -- cars drive over bridges, the Empire State Building sways in the wind and absorbs millions of footsteps. The cornerstone of the Empire State Building isn't warmer because it's under compression; it's warmer because it dissipates energy from swaying and vibration. > One very consistent problem in LIT over the last year has been > a very limited interest in the engineering realities of a > situation, and to much fondness for endless equation wars. These are not equation wars; as this message shows, you don't always have to use math to talk about physics. We are talking about very real physics concepts, and I'm afraid you are the one who has a few important ones wrong. Before we can do the detailed engineering for a starship, we need to understand what physical constraints it will be under. Even the best engineering cannot violate the laws of physics. If we are engaged in "equation wars", it is because we are trying to figure out the limits of what is possible before we do detailed design work based on faulty assumptions. This is the most fundamental interest in engineering realities you could want. From popserver Wed Dec 27 06:39:47 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["631" "Tue" "26" "December" "1995" "21:45:58" "-0800" "Steve VanDevender" "stevev@efn.org" nil "15" "RE: RE: Engineering Newsletter" "^From:" "David@InterWorld.com, hous0042@maroon.tc.umn.edu, jim@bogie2.bio.purdue.edu, KellySt@aol.com, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl" "David Levine, hous0042@maroon.tc.umn.edu, jim@bogie2.bio.purdue.edu, 'KellySt@aol.com', rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl" "12" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.2/8.7.2) with ESMTP id WAA15692; Tue, 26 Dec 1995 22:32:54 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id VAA04686; Tue, 26 Dec 1995 21:45:58 -0800 Message-Id: <199512270545.VAA04686@tzadkiel.efn.org> In-Reply-To: References: From: Steve VanDevender To: David Levine Cc: "hous0042@maroon.tc.umn.edu" , "jim@bogie2.bio.purdue.edu" , "'KellySt@aol.com'" , "rddesign@wolfenet.com" , "RUSSESS@cellpro.cellpro.com" , "stevev@efn.org" , "T.L.G.vanderLinden@student.utwente.nl" , "zkulpa@zmit1.ippt.gov.pl" Subject: RE: RE: Engineering Newsletter Date: Tue, 26 Dec 1995 21:45:58 -0800 David Levine writes: > Oh, as for my previous post - I do apologize - I've checked my archives > and have also received some CCs from Steve and a few from Ric > (plus one from Zenon). I have pretty much been following up to whatever recipient list is attached to whatever post I'm commenting on. I noticed your name was on some of the messages we've been passing around. I've saved copies of most of the messages sent to me since I started receiving them. If you are interested I could arrange to get that mail folder to you. It's a bummer to hear about SunSITE; I had been depending on it as a Linux software archive too. From popserver Mon Jan 1 18:58:15 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1070" "Mon" "1" "January" "1996" "11:02:36" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "28" "Happy New Year" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id KAA25449 for ; Mon, 1 Jan 1996 10:56:44 -0800 (PST) Received: from sea-ts2-p17.wolfenet.com (sea-ts2-p17.wolfenet.com [204.157.98.135]) by wolfe.net (8.7.3/8.7) with SMTP id LAA16684; Mon, 1 Jan 1996 11:02:36 -0800 (PST) Message-Id: <199601011902.LAA16684@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Happy New Year Date: Mon, 1 Jan 1996 11:02:36 -0800 (PST) Happy New Year everyone!! Well, I have done the first of my new years projects. I created a mailing group for this group. No more cutting and pasting for this guy in the new year. Well, what do we want to get completed this year? Mission Plans were few. the mission still needs to be defined. Engins!! Boy, is that a topic. I don't know the physics of all of this but it seems that we just don't have the technology yet to get what we need for this project. I hope I'm wrong, soon. Without knowing the mission or propulsion, the size of the ship isn't known. Hab spaces are seem to be dependent on the first two. Crew size is determined by ship and habitat sizes. The means of getting to TC or where ever it is we decide to go does seem to revolve around a power plant though. The question, to me, is, if we can't do it yet, why not pick a more realistic and closer goal that we could expect to acchive by 2040 or 2050. The above opinions are my own and do not reflect those of the management. :-) Ric The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Tue Jan 2 03:16:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1692" "Tue" "2" "January" "1996" "00:36:50" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "39" "Re: Happy New Year" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA05399 for ; Mon, 1 Jan 1996 15:35:41 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12594 (5.67b/IDA-1.5 for ); Tue, 2 Jan 1996 00:36:45 +0100 Message-Id: <199601012336.AA12594@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Happy New Year Date: Tue, 02 Jan 1996 00:36:50 +0100 >Well, I have done the first of my new years projects. I created a mailing >group for this group. No more cutting and pasting for this guy in the new year. Didn't you do that before? How for heaven sake have you been archieving 140 letters? >Engins!! Boy, is that a topic. I don't know the physics of all of this but >it seems that we just don't have the technology yet to get what we need for >this project. I hope I'm wrong, soon. The problem is the amount of power needed, no technology of today except for H-boms can give us that power easely. >Without knowing the mission or propulsion, the size of the ship isn't known. >Hab spaces are seem to be dependent on the first two. If we want to go to TC, habsize doesn't depend on the kind of propulsion, we just NEEDS space to live and work in. Every extra kilogram that is not needed should be eliminated regardless of the type of engine. >The means of getting to TC or where ever it is we decide to go does seem to >revolve around a power plant though. The question, to me, is, if we can't do >it yet, why not pick a more realistic and closer goal that we could expect >to acchive by 2040 or 2050. What about a mission to Venus? The high temperatures would make it a nice challenge. Or the outer regions of our solar system, doing it as fast as possible, ie. using 1g all the time. The trip would take about 3 weeks. We could of course stay on Earth and look for a way to easely go to the bottom of the oceans. A submarine that isn't limited by 300 or 1000 metres of depth. >The best Beads come from RD Designs. Ric, are these Beads the beads on a cord? (I wondered about this since the first time I read your signature) Timothy From popserver Tue Jan 2 07:07:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1323" "Mon" "1" "January" "1996" "23:04:45" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "36" "Re: Happy New Year" "^From:" "T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "Timothy van der Linden, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id XAA21897 for ; Mon, 1 Jan 1996 23:05:26 -0800 (PST) Received: from sea-ts2-p41.wolfenet.com (sea-ts2-p41.wolfenet.com [204.157.98.159]) by wolfe.net (8.7.3/8.7) with SMTP id XAA14744; Mon, 1 Jan 1996 23:04:45 -0800 (PST) Message-Id: <199601020704.XAA14744@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Happy New Year Date: Mon, 1 Jan 1996 23:04:45 -0800 (PST) >>Well, I have done the first of my new years projects. I created a mailing >>group for this group. No more cutting and pasting for this guy in the new year. > >Didn't you do that before? How for heaven sake have you been archieving 140 >letters? What I ment was I created a "mailing list" under one heading. (LIT). It contains everyone's names who has been active in this e-mail newsletter. >What about a mission to Venus? The high temperatures would make it a nice >challenge. >Or the outer regions of our solar system, doing it as fast as possible, ie. >using 1g all the time. The trip would take about 3 weeks. >We could of course stay on Earth and look for a way to easely go to the >bottom of the oceans. A submarine that isn't limited by 300 or 1000 metres >of depth. 3 weeks? what speed would you be traveling at? I don't have the real figure but aren't our present space craft traveling at 10's of thousands of miles a minute? > >>The best Beads come from RD Designs. > >Ric, are these Beads the beads on a cord? (I wondered about this since the >first time I read your signature) I keep forgetting to turn off that darn thing. We seel strings of beads as well as bags of beads. Do you have an interest? I could get you some prices if you like. Ric The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Tue Jan 2 09:34:23 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["10557" "Tue" "2" "January" "1996" "01:30:13" "-0800" "Steve VanDevender" "stevev@efn.org" "<199601020930.BAA25497@tzadkiel.efn.org>" "231" "Re: C-ship" "^From:" "T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org" "Timothy van der Linden, stevev@efn.org" "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id BAA25840; Tue, 2 Jan 1996 01:29:04 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id BAA25497; Tue, 2 Jan 1996 01:30:13 -0800 Message-Id: <199601020930.BAA25497@tzadkiel.efn.org> In-Reply-To: <199601012207.AA10231@student.utwente.nl> References: <199601012207.AA10231@student.utwente.nl> From: Steve VanDevender To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: stevev@efn.org Subject: Re: C-ship Date: Tue, 2 Jan 1996 01:30:13 -0800 Timothy van der Linden writes: > >I am still trying to get enough understanding of special > >relativity theory to make sure I get things right. I also want > >to work out more of the mathematical techniques I will use. > > Once that is ready, writing the simulator is easy ;) Yes, and that's why I've spent all my time on that so far, with a relatively brief digression into astrophysics to develop a simple but adequate model of starlight and a 3-d star database from catalogs. > >The basic structure of the simulation will be to model worldlines > >for all objects, and compute visibility for display by tracing > >light-like worldlines from a observer point to the other > >worldlines in the simulation in some common frame, then transform > >apparent positions of these objects in the common frame into the > >frame of the observer. > > Indeed, but for this you need to have a history of all the objects positions. > As long as they move linear or linear accelerated that's not so difficult > because you can use a function. But as soon as the behaviour gets less > simple you may need large arrays and with it come less precise calculations. > Also it would be nice to see the time at every point of the several objects > (for example by halting the simulation and clicking with the mouse). I realize that a motion history is necessary. In fact, the fundamental information associated with a typical object will be a worldline, consisting of straight and accelerated segments. The worldline represents the full motion history of an object, so in theory you could go to any point in spacetime in any frame and get a view of the universe by tracing intersections to the worldlines of all the other objects, then transforming those displacements into the view frame. I recognize the problem of dealing with more complicated types of motion. I at least want to work out a reasonable method of handling orbital motion so you can see what it looks like to boost into or out of a solar system. > >I think most of the relativistic effects, particularly things > >like aberration and rotation induced by moving at relativistic > >speed, can come out of fundamental behavior of the simulation > >rather than having to be explicitly calculated in each case. > >Aberration is simply a result of the way worldlines of light rays > >Lorentz-transform. > > Rotation will indeed follow from the finite speed of light. But I don't see > how abberation does not show up after the LT of the worldlines. Lightrays > coming form the backside of the observer won't come from the front after the LT. Check out the exercises in Chapter L (that's what they call it) of _Spacetime Physics_. Aberration and the "headlight effect" both follow directly from the geometry of the Lorentz transformation applied to light rays. Remember that a displacement along a worldline of a light ray is different than a plain spacial displacement, so applying a Lorentz transform to it produces a different result. Try out the numbers and I think you'll be surprised. I just ran an example for myself with a Lorentz transform matrix for a boost of 0.9 c in the x direction, and light rays coming from a perpendicular direction (say from along the y or z axes). They really do end up looking like they're in front of you when transformed into the "moving" frame. > >Rather than seeing Lorentz contraction, you > >see object rotation, because you see light from farther parts of > >an object that came from it earlier than light from nearer > >parts. I am trying to prove to myself that all these effects > >will fall out of the simulation model I want to use; so far I am > >pretty confident that I'm on the right track. > > This rotation is only seen if the object moves along you, thus not towards you. Correct. If your optics all take into account the finite speed of light, though, you will not necessarily see the amount of Lorentz contraction you'd think. Farther portions of the object are seen farther back in time when they were farther away. > >>What I asked John Walker was that I would expect curved lines in the SHUTTLE > >>and FLYTHRU movies. I think this curvature would be result of the finite > >>travel speed of light, ie. light from further objects reach the observer > >>later than the light from nearer object. > > > >That effect should happen. > > I've been rethinking this bending of the lines today. And now I think that > the lines should be straight. The lines are only curved if the objects are > moving. If the observer is moving and the objects don't move this bending > will not occur. What do you think after reading this? > > This would mean that you could "easely" recognize moving objects because of > the curvature they have and that still objects don't have. Which is why you should be suspicious. In the case of a constant-velocity observer, it is not possible to decide whether the observer or its surroundings are moving. (An accelerated observer experiences something that the rest of the universe does not; an accelerated observer knows that he is accelerating.) The appearance of curvature for large fast-moving objects will happen. Your arbitrary decision of whether the object is still or moving does not affect the geometry of the light; you can simply apply a Lorentz transform to the situation where the ship is moving and the object is still and get the situation where the ship is still and the object is moving, with the same view from the ship. The appearance of curvature is an effect of the finite speed of light. A snapshot of a scene captures light that arrived at the camera all at the same time. So light from farther portions of an object must have been emitted earlier, when the farther portions were farther back in their motion history, in order to be seen at the same time as light from nearer portions. This effect only becomes pronounced if the object subtends a large part of the field of view and is moving at a large fraction of c. > Yes, you need to know the functions of motion several points of an object. > Let's call one point of the object P[t]. > Call the point of the observer O[t]. > What does the observer see at time T1? The observer sees an object if a > photon that left the object at time T0 reached the position O[T1]. > > So in formula's: > > c*(T1-T0)=Sqrt((O[T1]-P[T0])^2) c is the speed of light > > With this equation one can calculate T0. When knowing that, you can > determine the position of the object at T0, so then you know from what > direction and from how far the photon came. > > Do this for all object-points and you have a created the "see-able" world, > after that you could use the c-ship program. That's the basic approach, although I use 4-vectors to represent time and position in the same object. First, for a U = [ u0 u1 u2 u3 ] and V = [ v0 v1 v2 v3 ], U|V = u0*v0 - u1*v1 - u2*v2 - u3*v3 (Lorentz inner product), and U^2 = U|U. U^2 is the square of the spacetime interval of a displacement represented by U. Velocities are neatly represented by vectors V where V^2 = 1; the components of the vector can be interpreted as displacements in frame coordinates per unit object time. Convert a frame velocity V = [ 1 v1 v2 v3 ] into a unit vector by dividing all components by sqrt(V^2). If you are at a point S = [ t x y z ], and you want to view an object whose worldline is described by P(t') = P0 + V * t' = [ t0 x0 y0 z0 ] + [ v0 v1 v2 v3 ] * t', then the path of a light ray between S and P satisfies the equation (S - P(t'))^2 = 0, The solution is: t' = ((S - P0)|V - sqrt(((S - P0)|V)^2 - (S - P0)^2 * V^2)) / V^2 This is pretty much simple application of the quadratic formula, choosing the smallest solution to get the t' that corresponds to light leaving the object at an earlier time than the observer's. Things are substantially more complicated when dealing with accelerated worldlines. I've got a preliminary solution stated in similar terms as the above discussion; perhaps you'd like to check my math :-). You are at the point S = [ t x y z ] attempting to view an object whose coordinates are P(t') = 1/a^2 * [ a * sinh(a * t') ax * (cosh(a * t') - 1) ay * (cosh(a * t') - 1) az * (cosh(a * t') - 1) ] where the acceleration is represented by A = [ 0 ax ay az ] (in the object local frame) and a = sqrt(ax^2 + ay^2 + az^2) (the magnitude of the acceleration). So again, we want to solve the equation (S - P(t'))^2 = 0. Of course, the components of P(t') are much more complicated. I won't bore you with the full derivation, other than to note that it becomes easier to isolate t' by writing the sinh and cosh terms in terms of their definitions using exp (e^x). Eventually, you get: exp(a * t')^2 * (1 - A|S - a * t') + exp(a * t') * (a^2 * S^2 - 2 * (1 - A|S)) + (1 - A|S + a * t') = 0 It's convenient to make some substitutions for common subexpressions: k = 1 - A|S p = k - a * t' q = a^2 * S^2 - 2 * k r = k + a * t' So then applying the quadratic formula and isolating t' gives: t' = 1/a * ln((-q - sqrt(q^2 - 4 * p * r)) / (2 * p)) I have yet to program this expression into my calculator and play with some solutions to see if they have the predicted results. In particular, there should be regions of spacetime where you cannot see the accelerated object (see Chapter 6 of _Gravitation_). You will also note that this is a somewhat less general statement of the problem; it uses a frame in which the accelerated object was at rest at the origin of the frame. For a general solution you would need to transform the view point into the appropriate frame, apply this solution, and transform it back out afterwards. > >Now that I think about it, simple extensions to POVray for > >modeling relativistic effects probably wouldn't work well, > >because you really have to raytrace in four dimensions to > >properly model them. > > Indeed, although it is easy to calculate the length of the lightray, it is > much more difficult to know where all object where in the past. For the purposes of the guy's C-ship simulation he would have to model acceleration, at least, which would substantially complicate things. My plan for my simulation will be to develop some heuristics to find the right worldline segment to which to apply the analytic solutions above, and possibly some other heuristics to discard old pieces of worldlines that are no longer visible to other important simulation objects. From popserver Tue Jan 2 10:16:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1770" "Tue" "2" "January" "1996" "02:14:26" "-0800" "Steve VanDevender" "stevev@efn.org" nil "60" "Re: C-ship" "^From:" "stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl" "Steve VanDevender, Timothy van der Linden" "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id CAA26814; Tue, 2 Jan 1996 02:13:24 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id CAA25641; Tue, 2 Jan 1996 02:14:26 -0800 Message-Id: <199601021014.CAA25641@tzadkiel.efn.org> In-Reply-To: <199601020930.BAA25497@tzadkiel.efn.org> References: <199601012207.AA10231@student.utwente.nl> <199601020930.BAA25497@tzadkiel.efn.org> From: Steve VanDevender To: Steve VanDevender Cc: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Subject: Re: C-ship Date: Tue, 2 Jan 1996 02:14:26 -0800 Steve VanDevender writes: > Things are substantially more complicated when dealing with > accelerated worldlines. I've got a preliminary solution stated > in similar terms as the above discussion; perhaps you'd like to > check my math :-). > > You are at the point S = [ t x y z ] attempting to view an object > whose coordinates are P(t') = > > 1/a^2 * [ a * sinh(a * t') > ax * (cosh(a * t') - 1) > ay * (cosh(a * t') - 1) > az * (cosh(a * t') - 1) ] > > where the acceleration is represented by A = [ 0 ax ay az ] (in > the object local frame) and a = sqrt(ax^2 + ay^2 + az^2) (the > magnitude of the acceleration). > > So again, we want to solve the equation (S - P(t'))^2 = 0. Of > course, the components of P(t') are much more complicated. I > won't bore you with the full derivation, other than to note that > it becomes easier to isolate t' by writing the sinh and cosh > terms in terms of their definitions using exp (e^x). > > Eventually, you get: > > exp(a * t')^2 * (1 - A|S - a * t') + > exp(a * t') * (a^2 * S^2 - 2 * (1 - A|S)) + > (1 - A|S + a * t') > = 0 Sigh. That should actually be: exp(a * t')^2 * (1 - A|S - a * t) + exp(a * t') * (a^2 * S^2 - 2 * (1 - A|S)) + (1 - A|S + a * t) = 0 I wrote t' rather than the t component of S in a couple wrong places. > It's convenient to make some substitutions for common > subexpressions: > > k = 1 - A|S > p = k - a * t' > q = a^2 * S^2 - 2 * k > r = k + a * t' And these should be p = k - a * t q = a^2 * S^2 - 2 * k r = k + a * t > So then applying the quadratic formula and isolating t' gives: > > t' = 1/a * ln((-q - sqrt(q^2 - 4 * p * r)) / (2 * p)) Fortunately I still copied that correctly. From popserver Tue Jan 2 18:01:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["498" "Tue" "2" "January" "1996" "06:41:54" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "16" "New Year Resolutions" "^From:" "rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "rddesign@wolfenet.com, Timothy van der Linden, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id EAA29533 for ; Tue, 2 Jan 1996 04:41:36 -0800 (PST) Received: by maroon.tc.umn.edu; Tue, 2 Jan 96 06:41:55 -0600 In-Reply-To: <199601020704.XAA14744@wolfe.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: rddesign@wolfenet.com cc: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: New Year Resolutions Date: Tue, 2 Jan 1996 06:41:54 -0600 (CST) This year (1996) I resolve to: 1) to find a physically consistent means to slow down the Asimov from lightspeed, assuming that all the energy we want can be beamed from Sol. 2) to find a physically consistent means to beam that energy. 3) to buy and read "spacetime physics" note, "physically consistent" means that it satisfies all know physical laws, esp. conservation of momentum and energy Kevin PS Happy New Year Guys! May it be a healthy and productive one in all your pursuits. From popserver Tue Jan 2 18:28:20 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1544" "Tue" "2" "January" "1996" "19:27:10" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "41" "Re: Happy New Year" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA14593 for ; Tue, 2 Jan 1996 10:26:10 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA00685 (5.67b/IDA-1.5 for ); Tue, 2 Jan 1996 19:27:05 +0100 Message-Id: <199601021827.AA00685@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Happy New Year Date: Tue, 02 Jan 1996 19:27:10 +0100 ReplyTo: Ric >>What about a mission to Venus? The high temperatures would make it a nice >>challenge. >>Or the outer regions of our solar system, doing it as fast as possible, ie. >>using 1g all the time. The trip would take about 3 weeks. >>We could of course stay on Earth and look for a way to easely go to the >>bottom of the oceans. A submarine that isn't limited by 300 or 1000 metres >>of depth. > >3 weeks? what speed would you be traveling at? I don't have the real figure >but aren't our present space craft traveling at 10's of thousands of miles a >minute? The distance to Pluto is about 6E12 metres, you need half that distance to accelerate and the other half to decelerate. x = 0.5 g t^2 --> t = Sqrt(2x/g) = Sqrt(6E12/9.8) = 7.8E5 seconds = 9 days So it takes 9 days to accelerate and 9 to decelerate. Ok, how fast are we going after accelerating: 7.8E5 * 9.8 = 7.7E6 m/s = 2.1E6 km/h = 1.3E6 mph That is 0.026c and it will give us a gamma of 1.0033 The total trip will take about 5.5 minutes less due to the relativistic effects. >>>The best Beads come from RD Designs. >> >>Ric, are these Beads the beads on a cord? (I wondered about this since the >>first time I read your signature) > >I keep forgetting to turn off that darn thing. We seel strings of beads as >well as bags of beads. Do you have an interest? I could get you some prices >if you like. No, that won't be necessary, I wouldn't have a purpose for them. >Ric >The best Beads come from RD Designs. >Ric & Denisse Hedman There you did it again :) Timothy From popserver Thu Jan 4 03:09:44 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["960" "Wed" "3" "January" "1996" "21:00:38" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<960103205747_105827744@emout06.mail.aol.com>" "26" "Re: Happy New Year" "^From:" "rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA27165 for ; Wed, 3 Jan 1996 18:00:08 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id VAA18508; Wed, 3 Jan 1996 21:00:38 -0500 Message-ID: <960103205747_105827744@emout06.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Happy New Year Date: Wed, 3 Jan 1996 21:00:38 -0500 >What about a mission to Venus? The high temperatures would make it a nice >challenge. >Or the outer regions of our solar system, doing it as fast as possible, ie. >using 1g all the time. The trip would take about 3 weeks. >We could of course stay on Earth and look for a way to easely go to the >bottom of the oceans. A submarine that isn't limited by 300 or 1000 metres >of depth. >> 3 weeks? what speed would you be traveling at? I don't >> have the real figure but aren't our present space craft >> traveling at 10's of thousands of miles a minute? More like 20 - 30 thousand MPH. Far too slow to cover solar systems distences quickly. But we do know of much better systems. We could work on a Alpha Centuri flight. Thats closer to our capacity. Oh, as far as cabin space. Its going to need to be big because of the need for a large diameter centrafuge, and because the crew will need a lot of room to keep from going stire crazy! Kelly Kelly From popserver Thu Jan 4 03:09:45 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["10053" "Wed" "3" "January" "1996" "21:00:18" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<960103205728_105827437@emout06.mail.aol.com>" "224" "Re: Engineering Newsletter" "^From:" "T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA27273 for ; Wed, 3 Jan 1996 18:01:43 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id VAA18072; Wed, 3 Jan 1996 21:00:18 -0500 Message-ID: <960103205728_105827437@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Wed, 3 Jan 1996 21:00:18 -0500 Tim thanks for forwarding the missing letter. Re: Timothy replies to Kelly: > > >>You can't assume that more money is used for this, because I could assume > >>that more money is used for research for anti-matter containment and > >>creation. Both fusion and anti-matter are areas where little is known > >>about. > > > >I wasn't refering to LIT assumptions, only real world. But, if we are to > >assume a large scale space infastructure. I guess we can assume it was worth > >there while to develope fusion systems. > > Indeed, but so would anti-matter systems after a while. Fusion is an extreamly usefull general purpose technology. Anti-matter is far less so, and far more dangerous on the scale we would need. I wouldn't expect a lot of anti-mater ships in 50 years. > >>Doing research on a planet or building industries is still much more > >>interesting than flying back to Earth. And if it isn't more intersting, then > >>research will gives more fruits for the money than flying back would do. > > > >Building industries? I don't follow. > > For some kind of colonization. Even if it is used as "refresh" point for > future missions to other solarsystems, it needs some form of > selfsufficiency. Therefor it needs "farms" and buildings, you can't make > them all by hand, so you need some form of small industry. Oh, that would be beyond the resources and tech of the project. Also it seem a waste of time. Sort of novelty project for the record books. With no practical reason to stay perminently there the bases would be prefab ghost towns. Future missions to other solar systems would have to be based out of dynamic, growing, large scale, civilizations. Not out of a staging camp in the middle of nowhere. > >Research I can understand, but obviously they can't do that forever. > > Why not, there will be plenty to figure out. Forever? Do you expect earth to keep funding these people in this base forever? With continuous supply flights from sol to keep them going? We couldn't even keep the moon program going for more than a few months after it planted its flag. > >Nor do I expect to settle for living out the rest of their lives in the hab > >deck. > > Why don't you expect them to do that? I still don't see that as suicide, > they can live perfectly healthy lives. Thats like condeming somone to spend the rest of their lives in an apartment/shoping mall! Good researchers will want to retire or go on to other projects. Not sit around in a worn out ship, in the middle of nowhere, with nothing to do. > >I can't see corporations droping probably hundreds of billions of dollars on > >a project like this. It absolutly would have no short term benifit (decades > >at least) and advertizing would supply this kind of money. > > One Japanese building company is seriously thinking about how it could build > on the moon. Now it may be a sign of advancement(=adverticement) but in 20 > years they may be the first(=money) to build there. > Indeed one company would not have enough money, but one company alone could > not build a city, so several companies will take their share. > And after all, the government's money is in fact the money of the companies. Japanise think big (and talk big), but seldom can carry out those big plans. Companise are in busness to make money for people. If they don't do that, they are taking their investors money under false pretenses. Which can get their executives fired or jailed. Droping money on a scale like this for no reasone other than as a charity project for prospace people would be criminal mis-appropriation, and comercial suicide. Assuming they weren't thrown in jail, the company would be so weak another pragmatic company could easily take it over. > >International projects ARE A DISSASTER!! I was in the International Space > >Station Freedom Program, and can assure you it convinced about everybody that > >international cost everyone far more, slowed the program WAY down, and > >generally made it impossible. If a project like this requirers international > >particip[ation, it will be a write off. > > May be, but a single country couldn't do it either. I don't know all about > problems about Freedom, but wasn't NASA the main "sponsor"? A single country could have done it far cheaper and quicker then all combined. > Such a project would be a challenge for mankind, it would not ALLOW us to > work together, it would INSIST us working together. Maybe today such a > project will not work, but countries are aligning. I know this sound > biblical: "When all sheep listen to one herdsman...", but I think it's > better than that: "The sum of the parts is much more than the parts themselves". Sorry, no. In large projects like this the sum of the parts is the lowest common denominator of everyone. It becoming a big issue in the U.S. The more people you get on a project, the less energy and inovation is avalible. Things get bogged down, lost in committe misunderstanding, ecetera. Costs can go up to hundreds of times what a small tight group could do it for. Thats one of the reasons that over the last decade or two, NASA has been incapable of trying, or developing, cutting edge technologies or programs. > >> So how do we solve that? Walking in spacesuits all day isn't that much fun. > > > >Exploration is seldom a lot of fun. I can't think of anyway to solve the > >biohazard problem other than space suits, or staying in the ship and using > >tele-operated robots. > > Exploration isn't much fun? What else drives people to such far places... Curiosity, greed, a chalenge, desire for fame or acomplishment. Exploration is generally horiobly uncomfortable and life threatening. But its very chalenging, and its atractive to know your one of the few to ever do something, know something, etc... Even if you know its killing you. Like an anthro professor my wife had. He loved studying aborigional tribes in the backwaters of the Amazon, but he frely admitted everyone who does it expect that they've paid with decades off their life expectancy. A ground team to a worl with a eath like bioshpere could expect to losemost of the team over a couple of months even inside the biosuits. > >> The place I live is save, even if all the polar ice melts away. :) (33 > >> metres above sealevel) > >> What you write may be true, but is not complete, we have found cures for > >> many diseases and our understanding gets better all the time. In 50 years > >> this will only be better and more advanced. > > > >True, but its taken us centuries to get this far in our medical skills. We > >won't have centuries, or even decades, to learn how to fight the alien > >bio-hazards. > > In all these centuries we accumulated these skills, a lot of these skills > can be used as general solutions and not as specific solutions. Often if a > cure for one disease is found, a lot of similar diseases are cured too. > It is not the specific case that takes decades to develop but the general > solution. So since we want to know what is out there, we will study those > creatures that have the potential to make us ill. Probably that is enough to > find a specific cure. Since your dealing with radically differnt life forms. Its unlikely the old rules, or solutions, would hold. We mostly will be starting from scratch. After all, we have no experience with alien biospheres. > >>>So if we want to continue the SD project we should make it 2140 instead of > >>>2040. > >> > >> Very possibly > > > >If we shove the calendar to 2140 from 2050, we'ld have nothing to base it on. > > We would have to debate what type of physics, much less engineering we could > >assume. > > So, what should we do? The main problem is the source of power that we are > allowed to use. So before we start discussing how the engine looks, we > should know what techniques we can use and in what AMOUNT. -- We're in a serous bind. The tech we can expect in 50 years isn't enough for a T.C. flight. Or all but the most modest interstellar flights. NOr would they be that likely to be interested in footing a huge program. Yet if we back up the date by a hundred years we could be much more confident that they could do it, and do it affordably, but we wouldn't have any credible idea how! > >We obviously arn't going to NEED to go to another star system, and certainly > >we've never come up with a reason anyone would want to stay in this other > >starsystem. (Trade obviously isn't practical with the technology we're > >discusing.) But that doesn't meen people wouldn't be interested in finding > >out what is there. > > It could be a goal for better survival of the human species. Two > so separate worlds are unlikely to become extinct at the same time. Your not talking about two planets. Your talking about earth, a fleet of colony platforms in sol and an outpost in another star. And the outpost is totally dependand on sol. Put another way. Are we that likely to be so afraid of human extinction, that we'll rush to do such a project in 50 years? > The reason for people to stay in such a desolated area is quite obvious, to > start a new or other life. Think of the people that went to Australia the > last 50 years (not the prisoners), a lot of them wanted new chances. Chances > they could not realize at their previous home. My guess is that there are > millions of people that want to get away from their present life and start > somewhere else. Oh certainly. The united states gets several million of them a year! But, another star doesn't offer much opportunity. It isolated, expensive, no markets to go to, few resorces that you can get at. No home world to go to on vacation to. Your very dependand on the supply line from Sol, and their for far less independant than you would be in a colony in Sol. Also, the kind of people we would send on such a ship. Would be the ellete that would have a lot of opportunity back home. The people who want a new start, wouldn't be sent on the ship. Kelly From popserver Thu Jan 4 03:20:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["343" "Wed" "3" "January" "1996" "19:17:15" "-0800" "Steve VanDevender" "stevev@efn.org" nil "7" "Re: Happy New Year" "^From:" "KellySt@aol.com, rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "KellySt@aol.com, rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id TAA01802; Wed, 3 Jan 1996 19:16:07 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id TAA31203; Wed, 3 Jan 1996 19:17:15 -0800 Message-Id: <199601040317.TAA31203@tzadkiel.efn.org> In-Reply-To: <960103205747_105827744@emout06.mail.aol.com> References: <960103205747_105827744@emout06.mail.aol.com> From: Steve VanDevender To: KellySt@aol.com Cc: rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Happy New Year Date: Wed, 3 Jan 1996 19:17:15 -0800 KellySt@aol.com writes: > We could work on a Alpha Centuri flight. Thats closer to our capacity. Alpha Centauri is 4.3 lyr away. Tau Ceti is 10 lyr away. This is barely any difference as far as interstellar travel goes. If you can get to Alpha Centauri effectively, you can get to Tau Ceti with no more than about twice the travel time. From popserver Thu Jan 4 03:20:13 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["512" "Wed" "3" "January" "1996" "19:19:22" "-0800" "Steve VanDevender" "stevev@efn.org" nil "10" "Re: Engineering Newsletter" "^From:" "KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id TAA01934; Wed, 3 Jan 1996 19:18:12 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id TAA31210; Wed, 3 Jan 1996 19:19:22 -0800 Message-Id: <199601040319.TAA31210@tzadkiel.efn.org> In-Reply-To: <960103205728_105827437@emout06.mail.aol.com> References: <960103205728_105827437@emout06.mail.aol.com> From: Steve VanDevender To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Wed, 3 Jan 1996 19:19:22 -0800 KellySt@aol.com writes: > Fusion is an extreamly usefull general purpose technology. Anti-matter is > far less so, and far more dangerous on the scale we would need. I wouldn't > expect a lot of anti-mater ships in 50 years. Perhaps not, but the only fuel that you can use to reach high relativistic speeds with a ship that carries its own fuel is antimatter. A fusion-powered ship carrying its own fuel can't reach high relativistic speeds without fuel-to-payload ratios of 10^6 or higher (much higher). From popserver Fri Jan 5 01:46:10 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["710" "Thu" "4" "January" "1996" "17:50:35" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "21" "Engineering Newsletter" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA18283 for ; Thu, 4 Jan 1996 17:43:55 -0800 (PST) Received: from sea-ts1-p61.wolfenet.com (sea-ts1-p61.wolfenet.com [204.157.98.115]) by wolfe.net (8.7.3/8.7) with SMTP id RAA18479; Thu, 4 Jan 1996 17:50:35 -0800 (PST) Message-Id: <199601050150.RAA18479@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Engineering Newsletter Date: Thu, 4 Jan 1996 17:50:35 -0800 (PST) So what are we going to do? Our technology isn't quite there yet for the propulsion plant. I'm sure we could build the rest of the ship no problem. The people we would like to crew the ship and maybe colonize the new system probably won't want to go. We have funding problems. To small and not enought money. To large and you couldn't get folks to decide on when to have dinner much less pay for it. Where do we go? What do we do? Do we start in-system with projects on the moon and Mars and build to the larger prospect of inter-steller flight? Alpha Centauri is half the distance. Can we make it at half the speed? Ric the trouble maker :-) The best Beads come from RD Designs. Ric & Denisse Hedman From popserver Fri Jan 5 18:02:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["555" "Thu" "5" "January" "1995" "10:55:20" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "14" "Re: Happy New Year" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA14323 for ; Fri, 5 Jan 1996 01:54:15 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15120 (5.67b/IDA-1.5 for ); Fri, 5 Jan 1996 10:55:13 +0100 Message-Id: <199601050955.AA15120@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Happy New Year Date: Thu, 05 Jan 1995 10:55:20 +0100 Steve writes: >KellySt@aol.com writes: > > We could work on a Alpha Centuri flight. Thats closer to our capacity. > >Alpha Centauri is 4.3 lyr away. Tau Ceti is 10 lyr away. This >is barely any difference as far as interstellar travel goes. If >you can get to Alpha Centauri effectively, you can get to Tau >Ceti with no more than about twice the travel time. It depends, if you can just reach AC with a fusion engine in 15 years, then a round trip to TC would take at least 60 years. Not many would survive that trip simply because of age. Timothy From popserver Fri Jan 5 18:02:57 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7975" "Thu" "5" "January" "1995" "10:55:25" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "153" "Engineering Newsletter" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA14330 for ; Fri, 5 Jan 1996 01:54:24 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15130 (5.67b/IDA-1.5 for ); Fri, 5 Jan 1996 10:55:19 +0100 Message-Id: <199601050955.AA15130@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Engineering Newsletter Date: Thu, 05 Jan 1995 10:55:25 +0100 Timoty replies to Kelly: >Fusion is an extreamly usefull general purpose technology. Anti-matter is >far less so, and far more dangerous on the scale we would need. I wouldn't >expect a lot of anti-mater ships in 50 years. You shouldn't see anti-matter as a fuel, but more as efficient energy storage. Why is anti-matter not a fuel? Because we have to make it. Coparing these two is like comparing a petrol car with an electric car. The energy for an electric car has to come from other fuels. Although the weight advantage with electric cars may not be evident yet there are other advantages. One of the advantages is the independancy of the origin of the fuel source. If it is fusion, fission or solar energy all are easely converted to electric energy which is relative easy to handle. So what car-batteries are for us now, anti-matter will be for fast spacevessels. >Oh, that would be beyond the resources and tech of the project. Also it seem >a waste of time. Sort of novelty project for the record books. With no >practical reason to stay perminently there the bases would be prefab ghost >towns. Future missions to other solar systems would have to be based out of >dynamic, growing, large scale, civilizations. Not out of a staging camp in >the middle of nowhere. If it really is to get a entry in the record books and not much more that would really be a shame of all resources. If people really want to do that, I see the end of humanity near. About growing civilizations, I don't think that western cultures will expand that much. In the US the birthrate is 2.05 per female, in Europe it's about 1.8. So that would mean that population will decrease. The mean reason that Earth's population is still increasing are the less developed countries which have birthrates of 4 to 7. I think that families in developed countries have less children because of the care these children need (financial but also social/tutorial). So this means that we probably never need to go to other places. But if we want to explore and discover new places we may want outposts at many places. So building small colonies would not be that crazy then. These colonies would have two purposes, the outpost and a research function. There would probably many researchers that like to check a foreign planet. >Forever? Do you expect earth to keep funding these people in this base >forever? With continuous supply flights from sol to keep them going? We >couldn't even keep the moon program going for more than a few months after it >planted its flag. After some time they could have build a small colony with all facilities needed to live and work. The energy they need comes from TC itself. So Earth would need funding them, but since they have build a "nice" place in the middle of an interesting place they may be interested to hear something of them. You may argue that building a colony is difficult in an alien environment, but by that time we will have some experience in building things on the Moon or Mars. >> Why don't you expect them to do that? I still don't see that as suicide, >> they can live perfectly healthy lives. > >Thats like condeming somone to spend the rest of their lives in an >apartment/shoping mall! Good researchers will want to retire or go on to >other projects. Not sit around in a worn out ship, in the middle of nowhere, >with nothing to do. Other projects, they have all the choice they could have. Who's going to tell them that they cannot do what they want. The only limits are the ones of themselves. The people going there aren't the people who really want to retire, these are people that are born for exploration and research. (They really exist) My guess is that they wouldn't sit all the time in some ship or compartment, but that they would allow themselves to go to the planets surface (in spacesuits). >Sorry, no. In large projects like this the sum of the parts is the lowest >common denominator of everyone. It becoming a big issue in the U.S. The >more people you get on a project, the less energy and inovation is avalible. > Things get bogged down, lost in committe misunderstanding, ecetera. Costs >can go up to hundreds of times what a small tight group could do it for. And do you know why this happens, because everyone wants his own share and no one is prepared to accept an idea of an other because that will mean a loss of personal profit. >Thats one of the reasons that over the last decade or two, NASA has been >incapable of trying, or developing, cutting edge technologies or programs. Maybe even one country is too big? >> Exploration isn't much fun? What else drives people to such far places... > >Curiosity, greed, a chalenge, desire for fame or acomplishment. Exploration >is generally horiobly uncomfortable and life threatening. But its very >chalenging, and its atractive to know your one of the few to ever do >something, know something, etc... Even if you know its killing you. Sorry, I had a more lossy idea about the word exploration than you did, I meant approximately what you wrote. >Like an anthro professor my wife had. He loved studying aborigional tribes >in the backwaters of the Amazon, but he frely admitted everyone who does it >expect that they've paid with decades off their life expectancy. So that means a return trip won't be necessary. >Since your dealing with radically differnt life forms. Its unlikely the old >rules, or solutions, would hold. We mostly will be starting from scratch. > After all, we have no experience with alien biospheres. I doubt if they are so radically different, all lifeforms have to abide the laws of nature. Maybe some of them have found tricks that have not been found on Earth but that is why we are going there. And still if we know what doesn't work the chances of finding something that does work are enlarged. >We're in a serous bind. The tech we can expect in 50 years isn't enough for >a T.C. flight. Or all but the most modest interstellar flights. NOr would >they be that likely to be interested in footing a huge program. Yet if we >back up the date by a hundred years we could be much more confident that they >could do it, and do it affordably, but we wouldn't have any credible idea >how! So maybe we should say "a priori" that certain techniques are available. And discuss how and why these could be used. >Put another way. Are we that likely to be so afraid of human extinction, >that we'll rush to do such a project in 50 years? You can never tell :) people are worring about many things (like asteroids colliding with Earth or the Asimov :)) If humanity ever becomes extinct, it will be likely that it is not because of natural disasters. >Oh certainly. The united states gets several million of them a year! But, >another star doesn't offer much opportunity. It isolated, expensive, no >markets to go to, few resorces that you can get at. No home world to go to >on vacation to. Your very dependand on the supply line from Sol, and their >for far less independant than you would be in a colony in Sol. You indeed can't go on vacation, and it probably never will have more than 1000 inhabitants for the first 100 years. But as every place where people live, they will adapt themselves and the environment. Not all people want to become rich by selling stuff, a lot of them just want a place to life as they like with the "sky" as the only limit. As I said before dependancy is only a short time (if at all), once there is TC-light and gravity they can grow food just as on Earth. So the first necessaries of life should not be that difficult. >Also, the kind of people we would send on such a ship. Would be the ellete >that would have a lot of opportunity back home. The people who want a new >start, wouldn't be sent on the ship. If you are 25 to 30 how sure can you be that you are a member of that elite. Also it doesn't have to be a new start but a first very defiant start. Timothy From popserver Fri Jan 5 18:03:08 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["891" "Thu" "5" "January" "1995" "11:37:39" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "38" "" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id CAA15053 for ; Fri, 5 Jan 1996 02:36:26 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA17547 (5.67b/IDA-1.5 for ); Fri, 5 Jan 1996 11:37:32 +0100 Message-Id: <199601051037.AA17547@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Date: Thu, 05 Jan 1995 11:37:39 +0100 Available power sources: Fission Solar power Fusion Chemical Other? Available techniques: Beaming Energy storage in anti-matter Other? Places to go to: Tau Ceti (TC) Alpha Centaury (AC) Pluto Objectives: One way trip Two way trip Let's assume that all the above are possibilities. What we should do is calculate the size and feasability and discuss the (dis)advantages for all cases. We should NOT try to discard a method, but only give its advantages and disadvantages. Of course we have done a lot already, only we haven't ordered it very much. Maybe it is time to recapitulate our discussions. I think that we need a complete survey, of course every one knows a lot of it, but I think that we don't agree about everything yet, but we also don't know exactly what these differences are. So we should try to come up with a kind of report. (Of course easier said than done) Timothy From popserver Fri Jan 5 18:03:35 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3448" "Fri" "5" "January" "1996" "15:47:57" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "115" "Asimov DESIGN SPACE" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl, zkulpa@sunet.se" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl, zkulpa@sunet.se" "1" nil nil nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA22205 for ; Fri, 5 Jan 1996 06:46:08 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id PAA27365; Fri, 5 Jan 1996 15:47:20 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA18161; Fri, 5 Jan 96 15:47:57 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601051447.AA18161@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Cc: zkulpa@sunet.se Subject: Asimov DESIGN SPACE Date: Fri, 5 Jan 96 15:47:57 +0100 > From T.L.G.vanderLinden@student.utwente.nl Fri Jan 5 11:40:02 1996 > > Available power sources: > > Fission > Solar power > Fusion > Chemical > Other? > > Available techniques: > > Beaming > Energy storage in anti-matter > Other? > > Places to go to: > > Tau Ceti (TC) > Alpha Centaury (AC) > Pluto > > Objectives: > > One way trip > Two way trip > > Let's assume that all the above are possibilities. What we should do is > calculate the size and feasability and discuss the (dis)advantages for all > cases. We should NOT try to discard a method, but only give its advantages > and disadvantages. > Of course we have done a lot already, only we haven't ordered it very much. > Maybe it is time to recapitulate our discussions. I think that we need a > complete survey, of course every one knows a lot of it, but I think that we > don't agree about everything yet, but we also don't know exactly what these > differences are. > So we should try to come up with a kind of report. (Of course easier said > than done) > Here I would like to remind about my attempt (a year ago) to start recapitulation effort of all discussed options. Below follows the sketch of the beginning ;-)) of the DESIGN SPACE summary I have started then. There should be, of course, many more aspects listed, like target(s), life supply (e.g., stored food/hydroponics/farming; all crew awake/all crew hibernates(or something)/mixed, etc.), command structure, project financing.... &c &c. I think listing all the discussed possibilities, shortly and systematically, should help greatly in clearing the matter and see the whole forest instead of only trees (as Polish saying goes). *************************** * * * LIT "ASIMOV" * * Starship Design * * * *************************** Progress Report The DESIGN SPACE discussed: 1. Type of Mission: * Robotic * Fly-by (no braking nor stop at target) * Exploratory (stop at target & explore) * Pathfinder (ahead of manned one: scouting/early warning) * Supply (after the manned: catching on the way or at target) * Manned: * Without crew procreation * Suicide (explore and die before your time when supplies end) * One-way (outpost construction and stay till natural death) * Round-trip (return to Earth, possibly with some crew left at the outpost) * Multi-step (start to new target from the previous one) * Multigenerational * Short-range, but long (slowship) * Long-range, thus long even though fast (fastship) * Colonization 2. Type of Propulsion * Main source * All fuel on-board * Use the interstellar medium * Power from installations at Solar system * Main type * Fission * Fusion * Antimatter * Sails * Other? 3. Gravity on board * Zero or small gravity * Near-g gravity * Centrifugal (rotational) * Whole ship * Habitat ring only * Tethered sections * Acceleration * Mixed 4. Mission composition * Single ship * Multiple ships * Manned plus robotic: * Pathfinder probes * Supply ships ---------------------------------------------------------- Hoping it may help, -- Zenon From popserver Fri Jan 5 18:03:47 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["173" "Fri" "5" "January" "1996" "07:57:15" "-0800" "Ric Hedman" "HEDMARC@cellpro.cellpro.com" nil "7" "Newsletters" "^From:" "KellySt%aol.com@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com" "KellySt%aol.com@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com" "1" nil nil nil nil] nil) Return-Path: HEDMARC@cellpro.cellpro.com Received: from cellpro.com (mail.cellpro.com [198.202.28.254]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id HAA25848 for ; Fri, 5 Jan 1996 07:52:58 -0800 (PST) Received: by cryovial.cellpro.com id <44804>; Fri, 5 Jan 1996 07:56:30 -0800 X-Nvlenv-01Date-Posted: 5-Jan-1996 7:57:20 -0800; at Bothell.CellPro Priority: Urgent References: <5041ED30025C2979@-SMF-> Message-Id: <96Jan5.075630pst.44804@cryovial.cellpro.com> From: HEDMARC@cellpro.cellpro.com (Hedman, Ric) To: KellySt%aol.com@cellpro.cellpro.com Cc: hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com Subject: Newsletters Date: Fri, 5 Jan 1996 07:57:15 -0800 Well. my system has crashed once more. Please send the newsletters to this address until furture notice:: hedmarc@cellpro.cellpro.com Sorry for all the trouble. :-) Ric From popserver Fri Jan 5 18:04:11 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["140" "Fri" "5" "January" "1996" "09:29:24" "-0800" "Ric Hedman" "HEDMARC@cellpro.cellpro.com" nil "6" "e-mails" "^From:" "T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com" "Timothy van der Linden, bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com" "1" nil nil nil nil] nil) Return-Path: HEDMARC@cellpro.cellpro.com Received: from cellpro.com (mail.cellpro.com [198.202.28.254]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id JAA01557 for ; Fri, 5 Jan 1996 09:17:24 -0800 (PST) Received: by cryovial.cellpro.com id <44805>; Fri, 5 Jan 1996 09:20:50 -0800 X-Nvlenv-01Date-Posted: 5-Jan-1996 9:21:26 -0800; at Bothell.CellPro In-Reply-To: <11009A30015C2979@-SMF-> References: <11009A30025C2979@-SMF-> Message-Id: <96Jan5.092050pst.44805@cryovial.cellpro.com> From: HEDMARC@cellpro.cellpro.com (Hedman, Ric) To: T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com (Timothy van der Linden) Cc: bpvanstr%yoho.uwaterloo.ca@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com Subject: e-mails Date: Fri, 5 Jan 1996 09:29:24 -0800 Well. my system crashed again. Please forward all Newsletters to me at work until I get my home system up and running again. Thanks, Ric From popserver Fri Jan 5 23:06:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["567" "Fri" "6" "January" "1995" "00:04:55" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "15" "Asimov DESIGN SPACE" "^From:" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA28495 for ; Fri, 5 Jan 1996 15:03:51 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28071 (5.67b/IDA-1.5 for ); Sat, 6 Jan 1996 00:04:49 +0100 Message-Id: <199601052304.AA28071@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Asimov DESIGN SPACE Date: Fri, 06 Jan 1995 00:04:55 +0100 Timothy replies to Zenon: Yes, Zenon I can remember that message very well. To be honest, when you wrote it, I thought, nice idea, but who's gonna do it. And in fact I'm still asking myself who's going to do it? I think I will try to make a start myself, but think it won't be much fun. But I think that now we have a much better idea about the several possibilities then a year ago, so a summary may be a bit more complete. >clearing the matter and see the whole forest instead of only trees >(as Polish saying goes). We have the same saying in Dutch... Timothy From popserver Sat Jan 6 05:05:28 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["3217" "Fri" "5" "January" "1996" "22:27:55" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "82" "Re: Asimov DESIGN SPACE" "^From:" "T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "Timothy van der Linden, KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA18170 for ; Fri, 5 Jan 1996 20:26:42 -0800 (PST) Received: by maroon.tc.umn.edu; Fri, 5 Jan 96 22:27:56 -0600 In-Reply-To: <199601052304.AA28071@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Asimov DESIGN SPACE Date: Fri, 5 Jan 1996 22:27:55 -0600 (CST) On Fri, 6 Jan 1995, Timothy van der Linden wrote: > Timothy replies to Zenon: > >clearing the matter and see the whole forest instead of only trees > >(as Polish saying goes). > > We have the same saying in Dutch... > Interesting, in english we say it the other way around: for example, "He can't see the forest for the trees" Now, for another drive proposal (you didn't possibly think I'd give up did you?) Consider the following Gedenken experiment: (inspired by actual events) you are standing on ice skates on very smooth ice (not completely frictionless, but then the ISM is not completely empty either) several hundred of your (friends?) throw snowballs at you, you catch them in a device that compresses a spring as each one is caught. Of course, as Steve teaches us, you begin to move across the ice. your friends continue to pelt you with snow balls, until you are moving with the speed of a thrown snowball (let's call it B). Halfway across the ice, you realize what will happen when you get all the way across the ice (and run out of ice) so you begin to throw your snowballs (using the energy stored in the spring) until you come to a nice stop on the far side of the ice. looking in your snowball holder, you notice that you still have some left, since the friction from the ice slowed you down a little. Of course, some of the snowballs may have melted, or small bits of snow could have rubbed off on the device, but I think you get the idea. Now, consider the the following engine design: Sol sends out a maser beam, and the "Asimov" absorbs it, turning it into electricity (let's say 80% eff) This gives the Asimov a nice 1 G accel. The energy is stored (if I knew how, I wouldn't need you guys ;) ) and later, at the halfway point, the beam from Sol stops. The "Asimov" gains some deceleration out of friction with the ISM (until you get down to about .90 C) and then releases the stored energy in the form of a maser beam generated by the "Asimov" and directed toward TC. Various transfer losses would probably leave you with some velocity even after you expended all of the stored energy. But I think that the velocity you would have left would be within the stopping range of a fusion engine. Once the antenna array was done absorbing the maser beam, it could be used for ISM drag chute, and we don't really care that it erodes away because by the time it's gone, we're below the speed where we get any useful drag. much better if a way can be found to hold the maser in a "mirrored box" and let it out with out needing conversion to electricity. I wonder, can Quantum mechanics help us here? can the wave be put in a box that allows only one harmonic to exist? Return trip is done the same way. Very simple timeline. all times relative to ship. 0 years -- leave earth 5 years -- arrive at TC, Send message informing earth. Begin assembling maser array for return trip. 5-15 yrs-- exploration / refuel / rebuild / 15 years-- maser array at TC finished. Send radio message informing earth 20 years-- arrive Sol eagerly awaiting responses. (esp. Steve and Tim -- renowned throwers of ice water) :) Kevin From popserver Sat Jan 6 05:05:32 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1866" "Fri" "5" "January" "1996" "23:37:29" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "43" "Re: Engineering Newsletter" "^From:" "rddesign@wolfenet.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl" "rddesign@wolfenet.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA18725 for ; Fri, 5 Jan 1996 20:38:37 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id XAA21403; Fri, 5 Jan 1996 23:37:29 -0500 Message-ID: <960105233728_33202780@emout06.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Fri, 5 Jan 1996 23:37:29 -0500 RE: rddesign@wolfenet.com > >So what are we going to do? > >Our technology isn't quite there yet for the propulsion plant. I'm sure we >could build the rest of the ship no problem. > >The people we would like to crew the ship and maybe colonize the >new system probably won't want to go. > >We have funding problems. To small and not enought money. To large and > you couldn't get folks to decide on when to have dinner much less pay > for it. > >Where do we go? What do we do? > >Do we start in-system with projects on the moon and Mars and build > to the larger prospect of inter-steller flight? > >Alpha Centauri is half the distance. Can we make it at half the speed? Well I made my cut at it a long time ago. A fusion ship could get to Alpha C. in about 20 years, maybe 12, and a bit quicker on the flight back with fuel launchers at each end. That might be short enough to interest the public and capable people. Moneys a problem. This is going to take some heavy coin to pay for, and its not very clear why we'd do it. Colonization doesn't make any sense (why spend decades getting somewhere to do something you could do better at home), and I've never heard of people putting up this kind of money for science. That leaves exploration. A fierce public desire to send someone out there with a camera and a flag. Some reason that people will want to feel really challenged and fund a national adventure. (International isn't feasible. The costs would explode, and you'd never be able to get anything done with that many people working on it.) Early 21st century we should be making a big push into space. By mid century we should have major industrial and tourist projects, and access to effectively unlimited raw materials. Maybe we will be pumped up and full of ourselves and be in the mood for a big adventure. Kelly From popserver Sat Jan 6 17:31:46 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2403" "Fri" "6" "January" "1995" "16:20:48" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "63" "Re: Asimov DESIGN SPACE" "^From:" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA05920 for ; Sat, 6 Jan 1996 07:19:38 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19553 (5.67b/IDA-1.5 for ); Sat, 6 Jan 1996 16:20:37 +0100 Message-Id: <199601061520.AA19553@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com Subject: Re: Asimov DESIGN SPACE Date: Fri, 06 Jan 1995 16:20:48 +0100 Timothy replies to Kevin: >> >clearing the matter and see the whole forest instead of only trees >> >(as Polish saying goes). >> >> We have the same saying in Dutch... > >Interesting, in english we say it the other way around: > >for example, > >"He can't see the forest for the trees" I guess that in both cases we can't see the forest because of the trees. In fact the Dutch saying is like you wrote it. Zenon uses a negated sentence and so changed the construction of the sentence and says the same... >Consider the following Gedenken experiment: (inspired by actual events) It should be "Gedanken Experiment" (it's German) >Now, consider the the following engine design: > >Sol sends out a maser beam, and the "Asimov" absorbs it, turning it into >electricity (let's say 80% eff) This gives the Asimov a nice 1 G accel. >The energy is stored (if I knew how, I wouldn't need you guys ;) ) The only way to store so much energy would be a matter & anti-matter mixture. Talk to Kelly if you want to hear why this wouldn't work :) >much better if a way can be found to hold the maser in a "mirrored box" >and let it out with out needing conversion to electricity. I wonder, can >Quantum mechanics help us here? can the wave be put in a box that allows >only one harmonic to exist? - What would be the advantage of one harmonic? - No two particles (photons) can be in the same state, so a single harmonic isn't possible. - There is a perfect one-way mirror: a blackhole - An unperfect mirror isn't usefull at all, even the slightest unperfection will give an almost 100% loss in a small time. (The box should at best be a sphere to avoid losses in the edges and joints. So in short your method could work but we don't know a way to store the energy. Besides that, if we could store that energy, it would be better to take it with us from the start, since than there would be no efficiency losses during capturing and beaming. So if we could create anti-matter efficiently and store it, it would always be cheaper then beaming. >5-15 yrs-- exploration / refuel / rebuild / > >15 years-- maser array at TC finished. Send radio message informing earth I wonder if about 100 (wo)men can build a 10 by 10 kilometre maser array (including a power source?) in 10 years. >(esp. Steve and Tim -- renowned throwers of ice water) :) I hope I've cooled you down enough :) Timothy From popserver Sat Jan 6 20:17:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1096" "Sat" "6" "January" "1996" "11:06:25" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "27" "Engineering Newsletter" "^From:" "T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "Timothy van der Linden, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id KAA15051 for ; Sat, 6 Jan 1996 10:59:38 -0800 (PST) Received: from sea-ts1-p50.wolfenet.com (sea-ts1-p50.wolfenet.com [204.157.98.104]) by wolfe.net (8.7.3/8.7) with SMTP id LAA13934; Sat, 6 Jan 1996 11:06:25 -0800 (PST) Message-Id: <199601061906.LAA13934@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Engineering Newsletter Date: Sat, 6 Jan 1996 11:06:25 -0800 (PST) >Steve writes: >>KellySt@aol.com writes: >> > We could work on a Alpha Centuri flight. Thats closer to our capacity. So, let's do something about this. If the fligh time is 15 years we should be able to trim that to 8 to 10 years some how. >> >>Alpha Centauri is 4.3 lyr away. Tau Ceti is 10 lyr away. This >>is barely any difference as far as interstellar travel goes. If >>you can get to Alpha Centauri effectively, you can get to Tau >>Ceti with no more than about twice the travel time. AC is 40% of the distance of TC. I'd say that there is more than "barely any difference". On a galaxtic scale, it's nothing. To humans it makes a big difference.. Kind of like walking to Denver from Seattle instead of walking to New York. I know I could probably do it if i had to. I don't even try and fool myself that I'd want to do that. Now, is there any thing at AC worth going there for? > >It depends, if you can just reach AC with a fusion engine in 15 years, then >a round trip to TC would take at least 60 years. Not many would survive that >trip simply because of age. > >Timothy > Ric From popserver Sat Jan 6 20:17:59 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9454" "Sat" "6" "January" "1996" "14:37:56" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "242" "Re: Asimov DESIGN SPACE" "^From:" "zkulpa@lksu.ippt.gov.pl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl, zkulpa@emin08.mail.aol.com, kgstar@most.fw.hac.com" "zkulpa@lksu.ippt.gov.pl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl, zkulpa@emin08.mail.aol.com, kgstar@most.fw.hac.com" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA16785 for ; Sat, 6 Jan 1996 11:39:25 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id OAA02840; Sat, 6 Jan 1996 14:37:56 -0500 Message-ID: <960106143755_33625202@emout05.mail.aol.com> From: KellySt@aol.com To: zkulpa@lksu.ippt.gov.pl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl cc: zkulpa@emin08.mail.aol.com, kgstar@most.fw.hac.com Subject: Re: Asimov DESIGN SPACE Date: Sat, 6 Jan 1996 14:37:56 -0500 >>>> I have an idea <<<< I mensioned to Tim that you couldn't build a ship that could carry a thousand times its own weight in fuel. True, but I forgot about staging! You start with a 1 billion ton fueled ship cluster driven by a 10 million ton engine and support structure (yeah right.). That engine is powerfull enough to push the whole mess at speed. When you burn off 95% of your weight in fuel. The ship cluster weighs 50 million tons, 20% of which is a first stage engine/structure thats WAY too powerful. You throw the first stage away and start a smaller secound stage. It weighs about 400,000 tons (about as much as 4 aircraft carriers) and can push the 40,000,000 ton ship cluster. When you burn that down to 2,000,000 tons of cluster you throw that away that stage for a 70,000 ton ship with 5-10,000 tons of drive systems. Which can use the remaining 390,000 tons of fuel to get itself into the system. stage total weight (tons) thruster pack and stage structure 1 1,000,000,000 10,000,000 2 40,000,000 400,000 3 2,000,000 70,000 ton ship with 5-10,000 tons of drive systems. This assumes a 100 to 1 thrust to weight ration for a fussion drive systems (which is questionable), and once you get where your going, coming back is out. But it would give us huge fuel ratios for relativistic flight. Possibly a multi stage fusion craft to get to the star and build a fuel launcher systems for two way flight? I'll have to think on this. > From T.L.G.vanderLinden@student.utwente.nl Fri Jan 5 11:40:02 1996 > > > > Available power sources: > > > > Fission > > Solar power > > Fusion > > Chemical > > Other? > > > > Available techniques: > > > > Beaming > > Energy storage in anti-matter > > Other? > > > > Places to go to: > > > > Tau Ceti (TC) > > Alpha Centaury (AC) > > Pluto > > > > Objectives: > > > > One way trip > > Two way trip > > > > Let's assume that all the above are possibilities. What we should do is > > calculate the size and feasability and discuss the (dis)advantages for all > > cases. We should NOT try to discard a method, but only give its advantages > > and disadvantages. > > Of course we have done a lot already, only we haven't ordered it very much. > > Maybe it is time to recapitulate our discussions. I think that we need a > > complete survey, of course every one knows a lot of it, but I think that we > > don't agree about everything yet, but we also don't know exactly what these > > differences are. > > > So we should try to come up with a kind of report. (Of course easier said > > than done) Good idea, we have pretty well argued threw everything, and a summary would be a good idea. Assuming we'ld dfo it. Several of us have suggested it. A fw said they were starting. Oh well. Using Zenons framework > Here I would like to remind about my attempt (a year ago) > to start recapitulation effort of all discussed options. > Below follows the sketch of the beginning ;-)) > of the DESIGN SPACE summary I have started then. > There should be, of course, many more aspects > listed, like target(s), life supply > (e.g., stored food/hydroponics/farming; > all crew awake/all crew hibernates(or something)/mixed, etc.), > command structure, project financing.... &c &c. > * LIT "ASIMOV" * > * Starship Design * You might have noticed I hate the name Asimov for the ship. It gives the whole project a grade school feel. I mean lets be real. This is a name that would never be acceptable to a real starship project. > The DESIGN SPACE discussed: > > 1. Type of Mission: > * Robotic > * Fly-by (no braking nor stop at target) > * Exploratory (stop at target & explore) > * Pathfinder (ahead of manned one: scouting/early warning) > * Supply (after the manned: catching on the way or at target) Fly by doesn't make much sence. If you just want to observe, you could do that just as well from here with big telescopes. Exploratory and Pathfinder have the same drive problems as the main ship, but greater funding problms and less capabilities. Pathfinder would be good as a warning scout ahead of the main ship though. > * Manned: > * Without crew procreation > * Suicide (explore and die before your time when supplies end) > * One-way (outpost construction and stay till natural death) Suicide and one way are the same. We couldn't biuld a self sustaining outpost, and wouldn't fund resupply flights forever unless there was something in it for us (or a fantastic improvement in star drives back home). NO ONE would fund a one-way flight. > * Round-trip (return to Earth, > possibly with some crew left at the outpost) About the only practical option. If we can't get them back, we woun't be allowed to send them. > * Multi-step (start to new target from the previous one) We are having a big problem even thinking how to get to one star and back. Multiples!? > * Multigenerational > * Short-range, but long (slowship) > * Long-range, thus long even though fast (fastship) > * Colonization We beat this one to death. - If its going to take you that long to get somewhere, wait for faster ships to be built. Since those ships will get there before you do anyway. - People who might want to go explore a star, certainly wouldn't settle for spending the rest of their days stuck in a ship with nothing to do. - The people who get there will have no allegence to the origional mission. In the United States about a century or two back, a lot of religious or other groups decided to go off into the wilderness and found a utopia. They eiather didn't plan and died out quick. Or they lasted about 2 generations. The grand children, didn't have their zeal, so they left, or rebuilt the city/culture along more conventional lines. Why would the grand kids bother to do our exploration for us. They never asked for this, and were never asked. I'ld bet they'ld eiather sit in the ship and wait for a followup mission to rescue them, or turn around and go home. - The people who get to the star wont be the ones you sent. They wont have the same skill mix as the first generation. They wont have any familiarity with planets, exploration, the shutles and rovers they'll need to use, etc.. - The ship would need to be much larger and better equiped to handel multiple generations (only one of which is working). Better medical, people will take more risks with their own lives then with their kids, and old people need MAJOR medical. Assuming we don't do the Canadian health care trick and just tell them their lives are no longer cost effective? - Equipment has a life expectency too folks! Usually less than 40 years. We wont be able rebuild everything in flight. So the ship will grow old and die around the crew. Even if it makes it, by the time it gets their its exploration gear will be in prety tired shape in the bay, and noone will remember how to fix it. (Sorry you can't just look it up in a VR sim.) Multi-gen is interesting in that its both technically more risky, expensive, etc.. and because of its long time lines, its certain to be a waste of time. Again, it will be certian to not get there first. Also there is a moral issue about throwing generations down a dangerous mission for no good reason. > 2. Type of Propulsion > * Main source > * All fuel on-board Not possible unless you have a very slow ship, or anti matter. Niether is very practical. Of course that assumes conventional physics. > * Use the interstellar medium We have no real idea how to, or for that matter know whats out there to use. > * Power from installations at Solar system Beamed power or fuel launchers have the advantage of offloading the need to carry the heavy fuel (and power systems) with the ship. That improves the ships power to weight ration significantly. But the systems are difficult to do, limit range, and don't seem to help us to slow down. > * Main type > * Fission > * Fusion > * Antimatter > * Sails > * Other? Fusion and anti-matter could power a ship. Microwave or laser sails could drive it. > 3. Gravity on board > * Zero or small gravity > * Near-g gravity > * Centrifugal (rotational) > * Whole ship > * Habitat ring only > * Tethered sections > * Acceleration > * Mixed I think the idea I came up with for a multi segmeny hab ring is the best. We need gravity for the crew, and the rotating hab segments will allow it to adapt to changing thrust directions. Unless the ship can operate under continuous thrust for the full flight. This seem best. > 4. Mission composition > * Single ship > * Multiple ships > * Manned plus robotic: > * Pathfinder probes > * Supply ships Given the size the main ship must be, I don't think we could afford 2. Which is a pity from a safty standpoint. A robotic pathfinder would be a good idea if it would work, but I'm dubious. A suply ship sounds a little risky. How would you like to be waiting in the target system for the next 5 years groceries. Kelly p.s. Zenon, did you CC yourself at an AmericaOnline account? (@emin08.mail.aol.com) From popserver Sat Jan 6 20:18:05 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2003" "Sat" "6" "January" "1996" "14:38:09" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "43" "Re: Asimov DESIGN SPACE" "^From:" "hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA16860 for ; Sat, 6 Jan 1996 11:41:29 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id OAA02915; Sat, 6 Jan 1996 14:38:09 -0500 Message-ID: <960106143806_33625334@emout05.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Asimov DESIGN SPACE Date: Sat, 6 Jan 1996 14:38:09 -0500 > >>>>>>>>>>>>>>>>>>>>>> Now, for another drive proposal <<<<<<<<<<< > > > you are standing on ice skates on very smooth ice (not > completely frictionless, but then the ISM is not completely empty > either) several hundred of your (friends?) throw snowballs at > you, you catch them in a device that compresses a spring as each > one is caught. Of course, as Steve teaches us, you begin to move > across the ice. your friends continue to pelt you with snow balls, > until you are moving with the speed of a thrown snowball (let's > call it B). Halfway across the ice, you realize what will happen > when you get all the way across the ice (and run out of ice) so you > begin to throw your snowballs (using the energy stored in the > spring) until you come to a nice stop on the far side of the ice. -- > -- > > > Now, consider the the following engine design: > > > Sol sends out a maser beam, and the "Asimov" absorbs it, turning > it into electricity (let's say 80% eff) This gives the Asimov a > nice 1 G accel. The energy is stored (if I knew how, I wouldn't > need you guys ;) ) and later, at the halfway point, the beam from > Sol stops. The "Asimov" gains some deceleration out of friction > with the ISM (until you get down to about .90 C) and then releases > the stored energy in the form of a maser beam generated by the > "Asimov" and directed toward TC. Various transfer losses would > probably leave you with some velocity even after you expended all > of the stored energy. But I think that the velocity you would have > left would be within the stopping range of a fusion engine.--- > One alternate that was discussed prevbiously would be to throw fusion fuel snowbals to same effect as first section. But of course thats probably impractical over large distences. Your stored microwave idea is interesting, but given the huge watage flows I can't think how to store it. Unless Tim's power to antimatter conversion systems would work. Kelly From popserver Sat Jan 6 20:18:11 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["164" "Sat" "6" "January" "1996" "14:52:06" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "9" "Re: Engineering Newsletter" "^From:" "rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA17378 for ; Sat, 6 Jan 1996 11:52:54 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id OAA03346; Sat, 6 Jan 1996 14:52:06 -0500 Message-ID: <960106145205_84893438@mail02.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl cc: hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Sat, 6 Jan 1996 14:52:06 -0500 to: Rick >> Now, is there any thing at AC worth going there for? Is there anything in Tau C? You got a problem with multiple star systems or something? Kelly From popserver Sat Jan 6 21:24:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1250" "Sat" "6" "January" "1996" "15:21:48" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "32" "Re: Engineering Newsletter" "^From:" "KellySt@aol.com, rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "KellySt@aol.com, rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com" "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA21657 for ; Sat, 6 Jan 1996 13:20:37 -0800 (PST) Received: by maroon.tc.umn.edu; Sat, 6 Jan 96 15:21:49 -0600 In-Reply-To: <960106145205_84893438@mail02.mail.aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: KellySt@aol.com cc: rddesign@wolfenet.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com Subject: Re: Engineering Newsletter Date: Sat, 6 Jan 1996 15:21:48 -0600 (CST) On Sat, 6 Jan 1996 KellySt@aol.com wrote: > to: Rick > > > >> Now, is there any thing at AC worth going there for? > > Is there anything in Tau C? You got a problem with multiple star systems or > something? > One reason to go to AC, would be to see if there are any planets, how far out they are, and so forth. The dynamicists tell us that we can expect them to be close in to one of the stars, or way out from both (all three?) but I've not seen anything that says just how far out or how close in. The opportunities for advancing our knowledge about multi-stared systems might just make the trip worthwhile. we could also see just how much comprhensible noise our star system makes. are we letting out a big Neon sign that blinks and says "Eat at Sol's", or are we such tiny whos that only Horton can hear us? (from a Dr. Suess book called "Horton hears a Who" for our non-native english members) As for the name "Asimov", I was under the impression that it was decided by vote, (although it now seems that we do it by rote) Anyway, you'll all be delighted to know that I now have a descent calculator again, a TI-92 $231.00 at the Univ. Bookstore. a thousand curses on the miscreant who stole my TI-85 >:-( Kevin From popserver Sat Jan 6 22:42:06 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4350" "Sat" "6" "January" "1996" "14:01:06" "-0800" "Steve VanDevender" "stevev@efn.org" nil "84" "Re: Asimov DESIGN SPACE" "^From:" "hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "Kevin C Houston, Timothy van der Linden, KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com" "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id OAA23388; Sat, 6 Jan 1996 14:00:57 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id OAA10967; Sat, 6 Jan 1996 14:01:06 -0800 Message-Id: <199601062201.OAA10967@tzadkiel.efn.org> In-Reply-To: References: <199601052304.AA28071@student.utwente.nl> From: Steve VanDevender To: Kevin C Houston Cc: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Asimov DESIGN SPACE Date: Sat, 6 Jan 1996 14:01:06 -0800 Kevin C. Houston writes: > [ . . . ] > > Now, consider the the following engine design: > > Sol sends out a maser beam, and the "Asimov" absorbs it, turning it into > electricity (let's say 80% eff) This gives the Asimov a nice 1 G accel. > The energy is stored (if I knew how, I wouldn't need you guys ;) ) and > later, at the halfway point, the beam from Sol stops. The "Asimov" gains > some deceleration out of friction with the ISM (until you get down to > about .90 C) and then releases the stored energy in the form of a maser > beam generated by the "Asimov" and directed toward TC. Various transfer > losses would probably leave you with some velocity even after you > expended all of the stored energy. But I think that the velocity you > would have left would be within the stopping range of a fusion engine. > Once the antenna array was done absorbing the maser beam, it could be > used for ISM drag chute, and we don't really care that it erodes away > because by the time it's gone, we're below the speed where we get any > useful drag. > > [ . . . ] > > eagerly awaiting responses. > > (esp. Steve and Tim -- renowned throwers of ice water) :) > > Kevin You'll probably die of shock, Kevin, but this idea, at least in concept, could actually work. Collecting and storing the immense energy required is likely to be almost impossible, but assuming that a method existed, this doesn't seem to violate the laws of physics. I'd like to present a similar idea framed in terms ofw a laser and a sheet of "slow glass" -- a material that was the main gimmick in a few science fiction stories by an author whose name I can't remember right now (darn it). Slow glass transmits light, but with a long time delay between when it comes in one side and goes out the other. In the stories, it was used for things like scenery windows -- a sheet of slow glass was set in a field for a few years, then put on the wall of a house, where it would release the years of scenery. Let's pick a sheet of slow glass that has a year-long delay between when it absorbs light on one side and re-emits it on the other. If we shine a laser at a sheet of slow glass, it will effectively appear to absorb the laser light, and the light's momentum, for the first year of its proper time. At the end of that year of proper time for the glass, the laser is turned off, and the absorbed laser light is emitted from the other side of the glass. Light continues to be emitted for another year of proper time for the glass, until all of the laser light absorbed has been emitted. At least to the first analysis, the glass must pick up momentum from the laser beam while it is absorbing the photons, and accelerates for as long as the laser is beamed at it. Then, when the light begins coming out the other side, the glass loses that momentum and decelerates. The end result seems like it ought to be that the glass ends up with some amount of spatial displacement from its original position, and the laser light passes through effectively unchanged, so that energy and momentum are conserved throughout. However, assuming a laser that emits constant power in its rest frame, the light intensity from the laser seen by the slow glass won't be constant. As the slow glass accelerates, the incident power from the laser will decrease from doppler shifting. Getting the glass to accelerate to high relativistic speeds will also cause the system of the glass and the photons absorbed to that point to increase significantly in mass (this isn't the same as what Timothy calls "relativistic mass increase" -- why?). So I'm a little troubled about the overall physics -- if the glass emits exactly the light it saw, then at the end of the first year of its proper time, if it emits the same light it saw at the beginning of the year, an observer in front of it would see that light tremendously blue-shifted if the glass was accelerated to high relativistic speeds. On the other hand, by the end of the second year of proper time of the glass, the light it emits is the very red-shifted light it was absorbing just before the laser turned off. I'm not sure, without doing the math, whether this comes out such that the energy emitted during the second year is the same as the energy absorbed during the first year. From popserver Sat Jan 6 23:17:38 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["591" "Sat" "6" "January" "1996" "15:17:58" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "22" "Re: Engineering Newsletter" "^From:" "KellySt@aol.com, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "KellySt@aol.com, KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl" "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id PAA26461 for ; Sat, 6 Jan 1996 15:11:31 -0800 (PST) Received: from sea-ts1-p50.wolfenet.com (sea-ts1-p50.wolfenet.com [204.157.98.104]) by wolfe.net (8.7.3/8.7) with SMTP id PAA26114; Sat, 6 Jan 1996 15:17:58 -0800 (PST) Message-Id: <199601062317.PAA26114@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: KellySt@aol.com Cc: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Sat, 6 Jan 1996 15:17:58 -0800 (PST) >to: Rick > > >>> Now, is there any thing at AC worth going there for? > >Is there anything in Tau C? You got a problem with multiple star systems or >something? > >Kelly > I have no problem with multi-star systems but will they support planets that would be stable for life? And you are right, Is there anything at TC worth going to either. The problems is were we live, and probably true for space as a whole, with few stars "close" to us. The problem of living in a spur of a sprial arm, kind of out of the mainstream. Like being in a town that the Intestate jogged around. :-) Ric From popserver Sun Jan 7 03:17:03 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4078" "Sat" "7" "January" "1995" "01:51:26" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "91" "Re: Asimov DESIGN SPACE" "^From:" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA01997 for ; Sat, 6 Jan 1996 16:50:18 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10800 (5.67b/IDA-1.5 for ); Sun, 7 Jan 1996 01:51:20 +0100 Message-Id: <199601070051.AA10800@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu Subject: Re: Asimov DESIGN SPACE Date: Sat, 07 Jan 1995 01:51:26 +0100 Timothy replies to Kelly: >stage total weight (tons) thruster pack and stage structure >1 1,000,000,000 10,000,000 >2 40,000,000 400,000 >3 2,000,000 70,000 ton ship > with 5-10,000 tons of > drive systems. > >This assumes a 100 to 1 thrust to weight ration for a fussion drive systems >(which is questionable), and once you get where your going, coming back is >out. But it would give us huge fuel ratios for relativistic flight. > Possibly a multi stage fusion craft to get to the star and build a fuel >launcher systems for two way flight? I'll have to think on this. I assumed that we could build a variable thrust engine, but for weight-savings staging may be better. I think that staging would not solve a more fundamental problem: Pressure One can see the engine as a force pressing on the back of the ship. We want a certain acceleration a. The heavier the ship gets, the bigger the force that is needed to get that acceleration (F=m*a). But assuming the backside of the ship stays about the same, the pressure (p=F/Area) gets bigger and bigger. So for a certain weight of the ship the pressure may become to big for any material to hold. (The backside of the ship is a loose expression, in fact it would be the support beams that connect the ship and the engine) >> * LIT "ASIMOV" * >> * Starship Design * > >You might have noticed I hate the name Asimov for the ship. It gives the >whole project a grade school feel. I mean lets be real. This is a name that >would never be acceptable to a real starship project. I never liked it much either, I guess the vote was done by passer-by-ers on the Web. I can recal that I added the optimistic name 'New Eden' :) What did you vote Kelly? >> * Manned: >> * Without crew procreation >> * Suicide (explore and die before your time when supplies end) >> * One-way (outpost construction and stay till natural death) > >Suicide and one way are the same. We couldn't biuld a self sustaining >outpost, and wouldn't fund resupply flights forever unless there was >something in it for us (or a fantastic improvement in star drives back home). > NO ONE would fund a one-way flight. I don't agree with you on that (yet?), I will expect an answer on my letter of 01-05 10:55. >> * Use the interstellar medium > >We have no real idea how to, or for that matter know whats out there to use. There is just too little, unless we can scoop an area with a 1000 km radius. >> * Power from installations at Solar system > >Beamed power or fuel launchers have the advantage of offloading the need to >carry the heavy fuel (and power systems) with the ship. That improves the >ships power to weight ration significantly. But the systems are difficult to >do, limit range, and don't seem to help us to slow down. Also they have a not so good efficiency. (A big part of the beam just flies along the ship without being used.) >> 3. Gravity on board > >I think the idea I came up with for a multi segmeny hab ring is the best. We >need gravity for the crew, and the rotating hab segments will allow it to >adapt to changing thrust directions. Unless the ship can operate under >continuous thrust for the full flight. This seem best. You would always need the rotating rings, because in the time that you spend at TC you don't have acceleration because of engine-thrust. >> 4. Mission composition > >Given the size the main ship must be, I don't think we could afford 2. Which >is a pity from a safty standpoint. A robotic pathfinder would be a good idea >if it would work, but I'm dubious. > >A suply ship sounds a little risky. How would you like to be waiting in the >target system for the next 5 years groceries. The idea of supply ships is to send them first and wait for them to arrive savely, unfortunately that would take 20 years from their launch. No a good way for food. Timothy From popserver Sun Jan 7 03:17:06 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1118" "Sat" "7" "January" "1995" "01:51:37" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "25" "Re: Engineering Newsletter" "^From:" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA02001 for ; Sat, 6 Jan 1996 16:50:21 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10812 (5.67b/IDA-1.5 for ); Sun, 7 Jan 1996 01:51:31 +0100 Message-Id: <199601070051.AA10812@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu Subject: Re: Engineering Newsletter Date: Sat, 07 Jan 1995 01:51:37 +0100 !Warning this letter contains no important info! Timothy replies to Kevin: >One reason to go to AC, would be to see if there are any planets, how far >out they are, and so forth. The dynamicists tell us that we can expect >them to be close in to one of the stars, or way out from both (all three?) >but I've not seen anything that says just how far out or how close in. >The opportunities for advancing our knowledge about multi-stared systems >might just make the trip worthwhile. we could also see just how much >comprhensible noise our star system makes. are we letting out a big Neon >sign that blinks and says "Eat at Sol's", or are we such tiny whos that >only Horton can hear us? (from a Dr. Suess book called "Horton hears a >Who" for our non-native english members) And what is "a Who"? >Anyway, you'll all be delighted to know that I now have a descent >calculator again, a TI-92 $231.00 at the Univ. Bookstore. a thousand >curses on the miscreant who stole my TI-85 >:-( So now all you have to do is learn where what function can be found under these "10-function" buttons? Timothy From popserver Sun Jan 7 03:17:07 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3401" "Sat" "7" "January" "1995" "01:51:42" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "66" "Re: Asimov DESIGN SPACE" "^From:" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu" "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA02017 for ; Sat, 6 Jan 1996 16:50:30 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10820 (5.67b/IDA-1.5 for ); Sun, 7 Jan 1996 01:51:37 +0100 Message-Id: <199601070051.AA10820@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu Subject: Re: Asimov DESIGN SPACE Date: Sat, 07 Jan 1995 01:51:42 +0100 Timothy replies to Steve: >I'd like to present a similar idea framed in terms ofw a laser and >a sheet of "slow glass" -- a material that was the main gimmick >in a few science fiction stories by an author whose name I can't >remember right now (darn it). Slow glass transmits light, but >with a long time delay between when it comes in one side and goes >out the other. In the stories, it was used for things like >scenery windows -- a sheet of slow glass was set in a field for a >few years, then put on the wall of a house, where it would >release the years of scenery. The slowest glass would be diamond with a speed of light 2.4 times slower than vacuum. But maybe there are other material with a higher refractive index for other wavelengths. >At least to the first analysis, the glass must pick up momentum >from the laser beam while it is absorbing the photons, and >accelerates for as long as the laser is beamed at it. Then, when >the light begins coming out the other side, the glass loses that >momentum and decelerates. The end result seems like it ought to >be that the glass ends up with some amount of spatial >displacement from its original position, and the laser light >passes through effectively unchanged, so that energy and momentum >are conserved throughout. This is a really fascinating idea, I wish I had thought of it. >However, assuming a laser that emits constant power in its rest >frame, the light intensity from the laser seen by the slow glass >won't be constant. As the slow glass accelerates, the incident >power from the laser will decrease from doppler shifting. >Getting the glass to accelerate to high relativistic speeds will >also cause the system of the glass and the photons absorbed to >that point to increase significantly in mass (this isn't the same >as what Timothy calls "relativistic mass increase" -- why?). Yes why, I don't understand, the glass is just a fast moving mass, so it will increase in mass due to a higher velocity. Of course the photons add some extra weight (m=Ephoton/c^2) >So I'm a little troubled about the overall physics -- if the glass >emits exactly the light it saw, then at the end of the first year >of its proper time, if it emits the same light it saw at the >beginning of the year, an observer in front of it would see that >light tremendously blue-shifted if the glass was accelerated to >high relativistic speeds. On the other hand, by the end of the >second year of proper time of the glass, the light it emits is >the very red-shifted light it was absorbing just before the laser >turned off. I'm not sure, without doing the math, whether this >comes out such that the energy emitted during the second year is >the same as the energy absorbed during the first year. As far as I can tell this is indeed what happens the first light that comes out is blue shifted. But the last light that comes out isn't more red-shifted than when it entered, because when the last light comes out the glass isn't moving anymore. Of course this slow glass should be very "clear" otherwise most of the light would be really absorbed before it could leave. Now that we are talking about slow-glass, did you know that you could make a photon stand still relative to you. Just shoot it in a bar of glass, then move the glass with about 0.7c in the opposite direction. The photon will then not move relative to you. Timothy From popserver Sun Jan 7 18:02:49 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["728" "Sun" "7" "January" "1996" "08:23:28" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "24" "Re: Engineering Newsletter" "^From:" "T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com" "Timothy van der Linden, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com" "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA00900 for ; Sun, 7 Jan 1996 06:22:18 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 7 Jan 96 08:23:28 -0600 In-Reply-To: <199601070051.AA10812@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hedmarc@cellpro.cellpro.com Subject: Re: Engineering Newsletter Date: Sun, 7 Jan 1996 08:23:28 -0600 (CST) On Sat, 7 Jan 1995, Timothy van der Linden wrote: > >only Horton can hear us? (from a Dr. Suess book called "Horton hears a > >Who" for our non-native english members) > > And what is "a Who"? read the book ;) I wouldn't want to spoil the end for you. :) > > >Anyway, you'll all be delighted to know that I now have a descent > >calculator again, a TI-92 $231.00 at the Univ. Bookstore. a thousand > >curses on the miscreant who stole my TI-85 >:-( > > So now all you have to do is learn where what function can be found under > these "10-function" buttons? > yeah, and I'm really upset that the physical constants and the metric conversions aren't on the TI-92, that was half the value of the TI-85 Kevin From popserver Mon Jan 8 19:58:44 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5900" "Mon" "8" "January" "1996" "20:55:12" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "145" "Re: Asimov DESIGN SPACE" "^From:" "hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, kgstar@most.fw.hac.com, zkulpa@sunet.se" "hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, kgstar@most.fw.hac.com, zkulpa@sunet.se" "1" nil nil nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA23486 for ; Mon, 8 Jan 1996 11:52:45 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id UAA02886; Mon, 8 Jan 1996 20:53:55 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA26153; Mon, 8 Jan 96 20:55:12 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601081955.AA26153@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, kgstar@most.fw.hac.com Cc: zkulpa@sunet.se Subject: Re: Asimov DESIGN SPACE Date: Mon, 8 Jan 96 20:55:12 +0100 > From KellySt@aol.com Sat Jan 6 20:43:10 1996 > [...] > Good idea, we have pretty well argued threw everything, and a summary would > be a good idea. Assuming we'ld dfo it. Several of us have suggested it. A > fw said they were starting. Oh well. Using Zenons framework > > > Here I would like to remind about my attempt (a year ago) > > to start recapitulation effort of all discussed options. > > Below follows the sketch of the beginning ;-)) > > of the DESIGN SPACE summary I have started then. > > There should be, of course, many more aspects > > listed, like target(s), life supply > > (e.g., stored food/hydroponics/farming; > > all crew awake/all crew hibernates(or something)/mixed, etc.), > > command structure, project financing.... &c &c. > > > * LIT "ASIMOV" * > > * Starship Design * > > You might have noticed I hate the name Asimov for the ship. It gives the > whole project a grade school feel. I mean lets be real. This is a name that > would never be acceptable to a real starship project. > The name arised from the vote by LIT members. I did not vote - I missed the deadline... My proposal would be different, though Asimov-like: "FarStar". However, on second thoughts, it should possibly be changed to "NearStar", to be more real...;-)). Acceptable for the real thing or not, it seems good enough as our "working name" in discussions. When starting to build the real thing :-) we can announce the name competition again... Concerning my "preliminary sketch of the beginning of the Design Space topics listing" :-)), I think we should first finish the (well ordered & structured) listing of the topics in the Design Space instead of arguing again over these few topics I have listed which were over-argued back and forth already... And the rationale for the listing is NOT to list options which we (who are we, anyway?) AGREED upon (I am afraid there are a few, if any, of them - even the name semms to be still disputable...), but to list ALL the options proposed, in a structured way, to give us insight about the full range of possibilities and their interdependence (something like the list obtained after the first stage of a brainstorming session). Such a listing may be then used as a structuring device for collecting the results of/positions taken during the discussion, showing, e.g., the holes in the arguments or (im)possibilities that were missed somehow, etc. In this way we may come at the only(!? - any other ideas?) useful and READABLE (in the finite time left us... ;-)) summary of the discussion and progress made so far. Without this, I am afraid further discussion would be a waste of time: as many of you complain, we are already either going around in circles, endlessly repeating the arguments and ideas that just happen old enough to be forgotten by most of the remaining participants, or are trying to devise more and more outlandish SF ideas without knowing whether they are really necessary (or whether they were not discussed a year ago...). I know it may be boring, such compilation and structuring of topics, but it is inevitable if the whole LIT affair is to have any further sense. I have made a beginning - let someone else adds a few more topics to the list (from his favourite domain) - we will then shortly discuss and refine the composition of this additional fragment of the list (NOT discussing the pro/contra of the topics on it - THAT was discussed upon already!), then go to the next few... Thus, Kellys discussion of the options on my list is rather off (current) topic - there are many arguments pro/contra the options listed (as for me, I have the opposite opinion to at least some arguments given by Kelly in his letter), but this is no time to repeat them - first, we should list all options discussed, then recapitulate shortly the previous arguments (the even MORE BORING part of the job... ;-)) using the list as a Table of Contents, and then start arguing again for the topics we find not (over-)discussed yet satisfactorily. Thus, despite the (AAAFFFULLL!) itching, I try to refrain from arguing with Kelly's opinions on the topics I listed. Ohhh my, except that one: ;-O ------------------------ > > * Manned: > > * Without crew procreation > > * Suicide (explore and die before your time when supplies end) > > * One-way (outpost construction and stay till natural death) > > Suicide and one way are the same. > Kelly, try to be logical. They are NOT the same (for short explanation - see inside brackets above). > We couldn't biuld a self sustaining > outpost, > If so, we couldn't build the (tens-of-years)-self sustaining space ship, either... > and wouldn't fund resupply flights forever > You assume the outpost crew will live forever? [see above]. And with the presently foreseable technology, the return flight will last just around the life expectancy of the outpost crew (oh, let add some 10 yers or so); thus the return will have almost only one sense - to bury the crew bones in the Earth grave (rather than in Space...). Or either we should assume "a fantastic improvement in star drives" (your words, Kelly...). No question in this case - we should plan a round-trip mission (but, I am sure, quite a number of the crew will want to stay back at the outpost anyway - I would, for that matter). [...] > NO ONE would fund a one-way flight. > Did you ask EVERYone, so you are so cock-sure about that "NO ONE" thing? ------------------------------------------ Enough, Zenon, do not indulge yourself in the pleasure of arguing with Kelly, against your own advice... > p.s. > Zenon, did you CC yourself at an AmericaOnline account? > (@emin08.mail.aol.com) > I do not think so. At least I am not aware of having any contacts with AOL. Why do you ask? -- Zenon From popserver Mon Jan 8 21:55:47 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2399" "Mon" "8" "January" "1996" "16:51:58" "-0500" "David Levine" "David@interworld.com" nil "85" "Re: Asimov DESIGN SPACE" "^From:" "T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu, david@interworld.com" "Timothy van der Linden, KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu, david@interworld.com" "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id NAA02271 for ; Mon, 8 Jan 1996 13:51:30 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.1 ID# 0-11464) with SMTP id AAA259; Mon, 8 Jan 1996 16:55:40 -0500 Message-ID: <30F191FE.4573@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b3 (WinNT; I) MIME-Version: 1.0 References: <199601070051.AA10800@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hedmarc@cellpro.cellpro.com, hous0042@maroon.tc.umn.edu, david@interworld.com Subject: Re: Asimov DESIGN SPACE Date: Mon, 08 Jan 1996 16:51:58 -0500 Timothy van der Linden wrote: > >> * LIT "ASIMOV" * > >> * Starship Design * > > > >You might have noticed I hate the name Asimov for the ship. It gives the > >whole project a grade school feel. I mean lets be real. This is a name that > >would never be acceptable to a real starship project. > > I never liked it much either, I guess the vote was done by passer-by-ers on > the Web. I can recal that I added the optimistic name 'New Eden' :) > What did you vote Kelly? > Obviously, the ship can be called anything - that's the least of the worries. In the interest of accuracy, though, here's how the name was decided: (and again, remember, you guys are doing the work now, if you wish to rename it, please, by all means...) There was a two month period in which names were accepted for submission, and a one month voting period. Only 15 people voted. Internet apathy at its best. First choice got 3 points, second 2 points, and third 1 point. While many of the names on the list are no longer familiar, some of these people were pretty active at the time, and at least three were "faculty", whatever that meant. I can't remember what I voted for, except I think "Albert Einstein" was one of my favorites. People Who Voted: ----------------- Jason Patten Calvin Li Chris Dolan Robin Chapman Scott Dawson Elisa Derickson Timothy van der Linden Eric Moore Doug Lampert Jeff Balcerski Ges Seger Chad Barb David Levine Don Flint Kellie Miller Top Four Names: --------------- Asimov - 13 points Albert Einstein - 9 points Intrepid - 8 points Enterprise - 5 points Last Place: ----------- Bradbury - 1 point Raw Data: --------- Albert Einstein ********* Ambassador ** Ancient Mariner *** Asimov ************* Bradbury * Brain of Pooh ** Brave Endeavour *** Brave New World ** Cassandra's Redemption *** Challenger **** Copernicus **** Eagle ** Emissary *** Enterprise ***** Far Reach ** Intrepid ******** Galileo **** Kepler *** Lady Galadril **** New Eden *** Star Hack ** Star Tramp ** Thunder Road *** Yamato *** From popserver Mon Jan 8 22:56:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["226" "Mon" "8" "January" "1996" "14:27:12" "-0800" "Ric Hedman" "HEDMARC@cellpro.cellpro.com" nil "7" "My e-mails" "^From:" "david%InterWorld.com@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com, T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com" "david%InterWorld.com@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com, Timothy van der Linden" "1" nil nil nil nil] nil) Return-Path: HEDMARC@cellpro.cellpro.com Received: from cellpro.com (mail.cellpro.com [198.202.28.254]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id OAA03834 for ; Mon, 8 Jan 1996 14:15:00 -0800 (PST) Received: by cryovial.cellpro.com id <44801>; Mon, 8 Jan 1996 14:18:58 -0800 X-Nvlenv-01Date-Posted: 8-Jan-1996 14:19:42 -0800; at Bothell.CellPro Priority: Urgent References: <2449F130025C2979@-SMF-> Message-Id: <96Jan8.141858pst.44801@cryovial.cellpro.com> From: HEDMARC@cellpro.cellpro.com (Hedman, Ric) To: david%InterWorld.com@cellpro.cellpro.com, hous0042%maroon.tc.umn.edu@cellpro.cellpro.com, zkulpa%zmit1.ippt.gov.pl@cellpro.cellpro.com, jim%bogie2.bio.purdue.edu@cellpro.cellpro.com, RUSSESS@cellpro.cellpro.com, stevev%efn.org@cellpro.cellpro.com, KellySt%aol.com@cellpro.cellpro.com, T.L.G.vanderLinden%student.utwente.nl@cellpro.cellpro.com (Timothy van der Linden) Subject: My e-mails Date: Mon, 8 Jan 1996 14:27:12 -0800 Thank you one and all for assiting me during the inconvenence with the LIT newsletter mailings. I can now access e-mail from home again. Please send future newsletters to the: rddesign@wolfenet.com address. Thank you, Ric From popserver Mon May 1 19:28:35 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["10192" "Mon" "1" "May" "1995" "13:02:38" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "197" "Re: relativistic acceleration stuff" "^From:" nil nil "5" nil "relativistic acceleration stuff" nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA10241; Mon, 1 May 95 11:02:39 PDT Received: by maroon.tc.umn.edu; Mon, 1 May 95 13:02:41 -0500 Reply-To: Kevin C Houston In-Reply-To: <199504300023.RAA23296@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII X-UIDL: 799356346.067 From: Kevin C Houston Sender: Kevin C Houston To: Steve VanDevender Subject: Re: relativistic acceleration stuff Date: Mon, 1 May 1995 13:02:38 -0500 (CDT) On Sat, 29 Apr 1995, Steve VanDevender wrote: > Here I'm keeping things simple by measuring both mass and energy > in units of mass. What this means, though, is that to accelerate > 1 kg of mass to 0.9996 c, you need to convert a additional 35 kg > of mass completely to energy to apply to the original unit of > reaction mass. That's some power requirement! In the most ideal > case, you have to carry 35 times as much fuel as reaction mass to > get an exhaust velocity of 0.9996 c, _or_ receive that quantity > of energy from an outside source. For your example of wanting to > have 0.011645 kg accelerated to that velocity, the total power > required is 3.701E16 joules; therefore you have to receive beamed > power of 3.701E16 W in order to maintain a rate of 0.011645 kg of > reaction mass accelerated to 0.9996 c every second. This number (3.7 E+16 W) agrees quite well with my results. > > This is complicated further by redshifting; as you reach higher > and higher velocities the effective power from the beam > decreases. In order for the ship to maintain a consistent 10 > m/s^2 acceleration in its frame, the beamer has to continually > increase its power. > I looked at the redshifting problem, and decided that the sensible thing to do is decrease your acceleration as you approach light speed. in the ship's frame, the amount of time spent accelerating less than 10 m/s^2 is only about a week, and if the power starts out slightly higher than needed, then there is no shortfall at midpoint. > If you really could maintain 1 g acceleration in the ship frame, > you run into an even worse problem with getting beamed power -- > during the first year of acceleration, you watch the beam > decrease in power to effectively 0! If you continue the > acceleration using stored fuel on the ship, the beamer is > completely inaccessible to you -- your velocity approaches an > asymptote with slope c that intersects the origin at about t = 1 > yr. You are completely unable to receive anything from the other > side of that asymptote, or in other words power transmitted after > about the first year of beamer (Earth) time; it's very much like > a black hole event horizon opens up 1 lyr behind you. Of course, > in reality maintaining continuous acceleration indefinitely is > pretty much impossible, but you are going to have to expect that > you won't get much beamed power once you get very close to c. > Again, by decreasing your acceleration near the midpoint, you can avoid some of this problem by not getting too close to c. The rest of the problem dissappears (for me) upon noting that the beamer only has to beam about 1.5 years anyway, after that, any light that is beamed to T.C. will get there _after_ we've come to rest. also, the time dialation effect would keep _power_ (not energy) essentially constant wouldn't it? by that I mean that while red-shifted light would be falling on the dipoles, the amount that would fall per second would increase (beacuse our seconds would get longer). Also, because we have to decelerate at some point, power sent from earth after 1 year would still reach us and do us some good, when we are approaching T.C. > Here's a relativity puzzler that you might find enlightening (I > came up with it while I was thinking about these problems, and > while I haven't made a detailed analytical solution, I'm pretty > sure that I know what the answer is): You have two perfect > mirrors facing each other, exactly parallel. You create a > coherent beam of photons that will bounce continually back and > forth between the mirrors. The photons have momentum (and > therefore energy) p; the two identical mirrors each have mass m. > By reflecting off the mirrors, the photons will gradually > accelerate the mirrors, causing them to move apart; what are the > final velocities of the mirrors, and what happens to the beam of > photons? Without going into a detailed analysis, I would say that as the mirrors begin to accelerate, the reflected light would begin falling in energy (wavelength) and that the final speed would depend on the amount of energy in the beam of light and the mass of the mirrors; the final speed should be less than c, unless you have infinite time in which to accelerate. > There are several reasons why I think that a mass-based thruster > may be more advantageous than a photon-based one: > > 1) slowing down. You need a sail three times larger than otherwise > needed, in order to have the incident photons be in the right > direction. > > I don't know that I have the _Flight of the Dragonfly_ book, but > I do have the _Rocheworld_ serial that appeared in Analog, which > I think was the original publication of the book. I just looked > over it for a bit, and it appears to use an idea I hadn't > originally been thinking about, which is to use a sail initially > to accelerate, then to split the sail and use part of it to > reflect and focus energy backwards to the remaining part to > decelerate. I didn't see any hard figures leap out at me other > than the sail sizes, though; those agree with the figures you > imply. > This is one of the monsters in the light sail senario, "Dragonfly" weighs 10,000 tons (inner sail and 3000 tons payload) with a 300 Km dia inner sail, and a 1000 Km outer sail (outer sail alone weighs 72,000 tons) it acelerates at .01g for twenty years, and decelerates at .1 g for 2 years. I meant to say that it'd need three times the _energy_ for deceleration. I now see, that these sail sizes are smaller than the MARS (10000 Km) but the payload size of the MARS is much bigger (2,000,000) tons and we are going to accelerate at 1 Sg, so we wont have any medical problems (and we get that wonderful time dialation) > 2) drag and radiation at relativistic velocity. the best acceleration > is going to be one grav or slightly above, near turnaround point, we > get up to .999999....... of C (you pays your money and you takes your > decimal points) however, this is just where drag starts to play havoc > with your sail. the on coming protons (stripped hydrogens) _appear_ > much more massive than normal (of course). but because of > time-dialation effects, you encounter many more of them in a ship's > "day" than you would otherwise find in interstellar space. near > turnaround, we are going to pass through a volume of space of a > light-year length in around three days. if you have a huge sail, then > the force of the interstellar gale will slow you down fast! > > It's not that the incoming protons are more massive. It's that > they have more energy and momentum. This is kind of a picky > distinction, but at my current level of understanding it is > important. What I mean by saying that their mass has increased, is to say that the momentum and velocity dont add up with the rest mass. p=M*V but the momentum of the oncoming hydrogen coming at near light speed is not consistent with an atomic weight of one AMU it is consistent with a particle of mass of 1 AMU/sqrt(1-v^2/c^2) > > You could also blame the increased incidence of incoming protons > on Lorentz contraction; you get the same result. > Yes I know. > As far as I know, if the beamed power is coming in at radio > frequencies (weren't we talking about a microwave beamer?), the > reflector doesn't have to be one continuous sheet, like it would > be if you were using a visible-light laser. well, even the visible light sail that Foreward uesed, had tiny holes in it that were smaller than the wavelength of laser light ( but when the hero tripled the wavelength of light, (to get around a fensel zone lens that had not gotten enough federal funding), he forgot to mention whether the one-third sized wave lengths would passs through the sail Hee Hee Hee. > > 3)sail size. The sail size needed to accelerate at 1 grav is > horrendous, even for a "small" ship. See Robert L. Foreward's "Flight > of the Dragonfly" (if you haven't already.) > > Again, I don't see why a reflective sail is going to be any > larger than the antenna/collector needed to absorb the energy > rather than reflect it. retro reflection > > What I'm arguing is that if you are relying on beamed power to > reduce your mass load, then you are better off reflecting the > power to get thrust rather than using it to accelerate reaction > mass, at least for the acceleration phase of your trip. Here's > why: > > You don't discard all the reaction mass at once, as in the ideal > equation I derived earlier. In the early phases of the trip, you > are using your reaction mass to accelerate your remaining > reaction mass in addition to the payload mass. So you have to > throw more reaction mass during the early phases of the trip to > maintain constant acceleration. okay, I agree with the esthetics of yur argument, that is it makes sense that the same amount of energy will produce the same amount of acceleration regardless of it's use, but I would like to see a few calculations just to be sure. you've already calculated the amount of energy needed to accelerate the exhaust stream, now convert that energy to photons and calculate the amount of thrust gained by reflecting them. BTW, what kind of acceleration do you gain just by absorbing the photons, and not reflecting them? > > I do realize, however, that one way or another you're going to > have to carry reaction mass to _decelerate_, whether you throw it > out the back with the help of beamed power or not. It turns out > that even if you have the fabled photon rocket, getting to any > high fraction of c requires substantially more fuel than payload; > this fuel/payload ratio _squares_ if you intend to both > accelerate and decelerate under your own power. So a practical > design could very well involve using beamed power to accelerate > and stored reaction mass to declerate. > Actually, we can slow down and scoop up reaction mass needed for the final slow down. I posted a formula by which scoop size needed to get a 10m/s^2 deceleration can be figured. From popserver Tue May 16 19:46:03 GMT 1995 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["2715" "Tue" "16" "May" "1995" "08:20:07" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" "" "55" "Re: relativistic acceleration stuff" "^From:" nil nil "5" nil "relativistic acceleration stuff" nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA12176; Tue, 16 May 95 06:20:29 PDT Received: by maroon.tc.umn.edu; Tue, 16 May 95 08:20:08 -0500 In-Reply-To: <199504300023.RAA23296@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 800653470.026 From: Kevin C Houston To: Steve VanDevender Subject: Re: relativistic acceleration stuff Date: Tue, 16 May 1995 08:20:07 -0500 (CDT) Steve, I was going through my old E-mail, when I re-read this one from you and I think I have some newer (to me anyway) thoughts on them. On Sat, 29 Apr 1995, Steve VanDevender wrote: > required is 3.701E16 joules; therefore you have to receive beamed > power of 3.701E16 W in order to maintain a rate of 0.011645 kg of > reaction mass accelerated to 0.9996 c every second. > > This is complicated further by redshifting; as you reach higher > and higher velocities the effective power from the beam > decreases. In order for the ship to maintain a consistent 10 > m/s^2 acceleration in its frame, the beamer has to continually > increase its power. > This can be kept to an order of two magnitude. Beamer stays constant. > If you really could maintain 1 g acceleration in the ship frame, > you run into an even worse problem with getting beamed power -- > during the first year of acceleration, you watch the beam > decrease in power to effectively 0! But at the same (well I was gonna say time but that would lead to confusion) in the same way, the rate of change of everything on the ship decreases. It's just like going into a kind of hibernation. Thus the beamer sends out an energy pulse of about 2 L.Y. long. The crew then use the first L.Y.'s worth of energy to approach c to four or five decimals. The ship then nearly "keeps pace" with it's energy supply, and uses hardly any at all. This is possible because with very long time parameters, very little energy is needed to effect change, so that the crew "feels" awake, the clocks and other (mechanical/electrical/ chemical/bio-chemical) systems behave normally within the frame of the ship itself. > If you continue the > acceleration using stored fuel on the ship, the beamer is > completely inaccessible to you -- your velocity approaches an > asymptote with slope c that intersects the origin at about t = 1 > yr. You are completely unable to receive anything from the other > side of that asymptote, or in other words power transmitted after > about the first year of beamer (Earth) time; it's very much like > a black hole event horizon opens up 1 lyr behind you. Of course, > in reality maintaining continuous acceleration indefinitely is > pretty much impossible, but you are going to have to expect that > you won't get much beamed power once you get very close to c. No, I won't get much beamed _energy_ , I'll have plenty of power tho' because each of my seconds becomes worth hundreds of beamer seconds. So when I absorb one seconds worth of energy, it suffices me for nearly two minutes beamer time because my demand for energy (in any form) has decreased. Kevin From popserver Wed May 17 19:29:24 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8094" "Wed" "17" "May" "1995" "08:39:28" "-0500" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "165" "Re: relativistic acceleration stuff" "^From:" nil nil "5" nil "relativistic acceleration stuff" nil nil] nil) Received: from maroon.tc.umn.edu by efn.efn.org (4.1/smail2.5/05-07-92) id AA01662; Wed, 17 May 95 06:39:41 PDT Received: by maroon.tc.umn.edu; Wed, 17 May 95 08:39:28 -0500 In-Reply-To: <199505162301.QAA13293@tzadkiel.efn.org> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-UIDL: 800738860.023 From: Kevin C Houston To: Steve VanDevender Subject: Re: relativistic acceleration stuff Date: Wed, 17 May 1995 08:39:28 -0500 (CDT) > Kevin C. Houston writes: > > > > > > This can be kept to an order of two magnitude. Beamer stays constant. > > What are you saying here? That the beam only has to vary in > magnitude by an "order of two", or that it stays constant? Both. The Beamer sends a constant wavelength. The ship only sees the wavelength vary by a factor of ~130 near midpoint. (velocity is limited to .99997 c due to the ship reducing acceleration before midpoint) > > To maintain constant acceleration _in the ship's rest frame_, the > ship must receive a constant amount of energy _in its frame_. As > the ship accelerates away from the beamer and reaches higher > velocities, _it will see the beamer output go down in energy_. > If you claim anything else, you haven't been studying your > relativity theory. You keep making the mistake (or the mis-type) of equating energy and power (power = energy/time) so that as time slows down, power goes up for an equal amount of energy or stays constant for a decreasing amount of energy. In order to maintain a constant acceleration, the ship must recieve a constant amount of _power_ in it's frame, and that can be affected by time dialation parameters. > > > If you really could maintain 1 g acceleration in the ship frame, > > > you run into an even worse problem with getting beamed power -- > > > during the first year of acceleration, you watch the beam > > > decrease in power to effectively 0! > > > > But at the same (well I was gonna say time but that would lead to > > confusion) in the same way, the rate of change of everything on the ship > > decreases. It's just like going into a kind of hibernation. Thus the > > beamer sends out an energy pulse of about 2 L.Y. long. > > The crew then use the first L.Y.'s worth of energy to approach c to four > > or five decimals. The ship then nearly "keeps pace" with it's energy > > supply, and uses hardly any at all. This is possible because with very > > long time parameters, very little energy is needed to effect change, so > > that the crew "feels" awake, the clocks and other (mechanical/electrical/ > > chemical/bio-chemical) systems behave normally within the frame of the > > ship itself. > > I don't think you understand what goes on. If the ship maintains > constant acceleration at 1G, it can only see about 1 year's worth > of power. IT NEVER SEES LIGHT EMITTED FROM THE BEAMER AFTER > THAT, UNTIL ITS ACCELERATION DECREASES. please don't shout. I understand full well what is going on here, I'm just having a little difficulting explaining what I mean to you. first point, I'n not talking about open-ended acceleration, I'm talking about the trip we are planning to T.C. the ship will be under acceleration for about 3/4 of a year. that is, they will only accelerate with power from the first 9 months of the beam. then they will turn around and begin decelerating. > > Draw a spacetime diagram with a hyperbola opening to the right > whose asymptotes are the lines t = x/c and t = -x/c. The > worldline of the uniformly accelerated ship corresponds to the > hyperbola. In this diagram, the ship starts at a nonzero x = 1/a > (a is the acceleration) at t = 0. Light is constrained to move > along worldlines of the form t = x/c + k and t = -x/c + k, for > any arbitrary constant k. What light lines can intersect the > hyperbola? At what times and locations can those light beams be > emitted in the global frame? Using the four regions bounded by > the asymptotes, you'll see that only light from the region below > t = x/c can ever reach the ship. Light from above that region > never reaches the ship. Similarly, the ship can only send light > to the region above t = -x/c. > Imagine yourself to be floating in space watching the trip from a long ways off. what would you see as a stationary observer. 1) Time=0 days Sol system begins beaming and "Asimov" begins accelerating. 2) Time~365 days. Ship reaches near light speed (time=c/a) dist ~.5 L.Y. 3) Time~547 days. Dist ~1 L.Y. Earth stops sending Beam. Ship and beam travel nearly as one, that is to say that the tail end of the beam does not move apreciably nearer to the ship. Time is very slow on ship by factor of ~130:1 4) dist=5.98 L.Y. ship begins decelerating. Tail end of beam begins to move toward ship again. 5) midpoint+547 days dist=11.9 L.Y. ship arrives at T.C. tail end of beam arrives at T.C. also > > No, I won't get much beamed _energy_ , I'll have plenty of power tho' > > because each of my seconds becomes worth hundreds of beamer seconds. So > > when I absorb one seconds worth of energy, it suffices me for > > nearly two minutes beamer time because my demand for energy (in any form) > > has decreased. > > No, you are mixing frames, and thereby ruining your argument. > Draw everything out in a frame that is inertial (the ship's frame > is accelerating, so it is invalid as an ongoing reference for > analysis in special relativity). When the beamer emits one > second of energy in your global frame, it takes much more time > than that along the ship's worldline for that second of energy to > be received when the ship is at high velocity. In the case of > sustained acceleration, only a finite amount of energy from the > beamer is ever visible to the ship; energy emitted after a time > 1/a (a is the acceleration in 1/m units) can never reach the > ship. I agree that we can't accelerate forever, and for the reason you state. However, by the time you had accelerated to that point, you're time rate would be so slow, that for all practical purposes you'd be standing still. (i.e. you could cover light-years of distance in a single "hour" of your awareness) the small amount of additional acceleration you might accomplish over these multi-light-years of space would feel like 10m/s^2 to you on the ship, but it wouldn't increase your energy or momentum very much (as measured by the outside observer) Ok, I'm traveling at .99997 c (no accel), and getting my power from a beam coming from behind. Power in the beam is 1000 KJ/s. The beam is at a wavelength of 130 cm as measured by the stationary beamer. So that the wavelength I "see" is 1 cm. (of course, I cooked the numbers). So the energy in the beam that I can use is 130 times less than if I were stationary or energy in one second of beam = 7.69 KJ. But my time rate is 130 times slower than the beamer's. so that I will recieve 130 seconds of beam (as measured by the beamer) in only 1 second (as measured by me) this is 7.69 *130 =1000 KJ. Time dialation conspires with lorentz contraction to provide me with the same amount of _power_. > > You really should sit down and read _Spacetime Physics_. You're > making elementary errors in reasoning about relativistic physics. > I have taken a modern physics course in college, although much of it was wave equations, we did have some relativity training. I will be reading "Spacetime Physics" and the gravitation book you mentioned over the summer. Since you have read these books recently, here's a project for you: come up with equations for the ship that: 1) show ships velocity as a function of ship time (St) assuming constant accel. ex. v=f(St,a) 2) show ship's distance from earth in earth-sized meters D as a function of ship time assuming constant accel. ex D (in meters)=f(St,a) 3) the amount of exhaust mass Em moving at .9996 c required to accelerate a ship at 10 m/s^2 (as felt by the crew) as a function of ship's total mass Mt. ex. Em=f(Mt,a) 4) the rest mass (as measured by the crew) of that exhaust. ex. Rm=f(Em,.9996c) 5) The power (in units of energy) needed on board to accelerate that mass flow to .9996c (assume stored energy on board to make it easier) ex. P=f(Rm,.9996c) This will enable us to track time and energy requirements of the "Asimov" much better than in the past. Hopefully I'll be able to dump these formulas into the spreadsheet, and model the trip much better. Kevin From popserver Sun Dec 31 18:13:11 GMT 1995 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1812" "Sun" "31" "December" "1995" "15:23:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "40" "Re: Engineering Newsletter" "^From:" nil nil "12" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA05466 for ; Sun, 31 Dec 1995 06:22:50 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA03264 (5.67b/IDA-1.5 for ); Sun, 31 Dec 1995 15:23:54 +0100 Message-Id: <199512311423.AA03264@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Sun, 31 Dec 1995 15:23:59 +0100 >This page is _so cool_ that I've stayed up until 3:30 am looking >at it: > >http://www.fourmilab.ch/cship/cship.html Yes, I had found it a month ago or so, and downloaded it all, (took some time though) now I've a copy at my own HDD. I had in mind telling you about it, but when 2 weeks ago I walked around in your netpage, I saw that you already had a link to C-ship. I tried contacting the author, but have a hard time getting answers. He only replied my first email very shortly. The next letter involved some questions but I haven't heard from him since. >Although his starship design is simplistic and intended more for >expository purposes than as a completely realistic design, it >does have some interesting features I haven't seen us discuss >before. In particular he discusses the need for streamlining (!) >for a ship that travels at high relativistic speeds. In essence >it's a self-powered ship fueled by antimatter. He assumes that the interstellar medium and the background radiation give much drag, I think that is neglectable for speeds under .99c (and probably even higher) >The coolest part, though, is a couple of MPEGs that show trips >through his imaginary "lattice galaxy" at relativistic speeds. >This is exactly the kind of thing I want to do with my starship >simulation program (still completely embryonic at this point), >but with a database of real stars in the Solar neighborhood. >View the MPEGs, and then we can talk about why it looks like >you're flying backwards at the start of a trip. These 6 mpeg have a total size of 5 Mb, so for the other who are interested, be warned. The rest of the pages is about 1 Mb including the images. I myself have some doubts about some points in the simulation, but as I said before, the author doesn't answer my questions. Timothy From popserver Tue Jan 9 05:53:05 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6344" "Mon" "8" "January" "1996" "21:40:15" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "165" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA23753 for ; Mon, 8 Jan 1996 18:40:14 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id VAA22883; Mon, 8 Jan 1996 21:40:15 -0500 Message-ID: <960108213807_86279596@emout06.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, hedmarc@cellpro.cellpro.com Subject: Re: Engineering Newsletter Date: Mon, 8 Jan 1996 21:40:15 -0500 > > to: Rick > > > > > >>> Now, is there any thing at AC worth going there for? > > > >Is there anything in Tau C? You got a problem with multiple star systems or > >something? > > > >Kelly > > I have no problem with multi-star systems but will they support > planets that would be stable for life? And you are right, Is there > anything at TC worth going to either. Who knows? We have no idea what areas life can handel. If nothing else a very different starsystem could answer a lot of questions, especiall with three stars of different types. Of course we'ld know where the planets were before we sent of the mission. > The problems is were we live, and probably true for space as a whole, with > few stars "close" to us. The problem of living in a spur of a sprial arm, > kind of out of the mainstream. Like being in a town that the Intestate > jogged around. :-) Unfortunatly, this is an unusually empty area of space. Both in starsystems and in interstellar matter. > > To Timothy: > > >stage total weight (tons) thruster pack and stage structure > >1 1,000,000,000 10,000,000 > >2 40,000,000 400,000 > >3 2,000,000 70,000 ton ship > > with 5-10,000 tons of > > drive systems. > > > >This assumes a 100 to 1 thrust to weight ration for a fussion drive systems > >(which is questionable), and once you get where your going, coming back is > >out. But it would give us huge fuel ratios for relativistic flight. > > Possibly a multi stage fusion craft to get to the star and build a fuel > >launcher systems for two way flight? I'll have to think on this. > > I assumed that we could build a variable thrust engine, but for > weight-savings staging may be better. Yes, the weight of the huge engines we'ld need at the start would dominate the ship after a little while. > I think that staging would not solve a more fundamental problem: Pressure > One can see the engine as a force pressing on the back of the ship. We want > a certain acceleration a. The heavier the ship gets, the bigger the force > that is needed to get that acceleration (F=m*a). But assuming the backside > of the ship stays about the same, the pressure (p=F/Area) gets bigger and > bigger. --- Do you mean the thrust loads? If so we will need to take that into consideration. But we can use some of the fuel or reaction mass as structure (ice perhaps?) and the structure needed to carry the load shouldn't be a major fraction of the fuel mass. > > >> * LIT "ASIMOV" * > >> * Starship Design * > > > >You might have noticed I hate the name Asimov for the ship. It gives the > >whole project a grade school feel. I mean lets be real. This is a name that > >would never be acceptable to a real starship project. > > I never liked it much either, I guess the vote was done by passer-by-ers on > the Web. I can recal that I added the optimistic name 'New Eden' :) > What did you vote Kelly? I never even heard their was a vote until the 'winner' was announced. Thou I guess since I picked Explorer for my design, that would count as a vote. > >> * Manned: > >> * Without crew procreation > >> * Suicide (explore and die before your time when supplies end) > >> * One-way (outpost construction and stay till natural death) > > > >Suicide and one way are the same. We couldn't biuld a self sustaining > >outpost, and wouldn't fund resupply flights forever unless there was > >something in it for us (or a fantastic improvement in star drives back home). > > NO ONE would fund a one-way flight. > > I don't agree with you on that (yet?), I will expect an answer on > my letter of 01-05 10:55. What letter? The ones in my inbox don't have that time? Given that fantastic trouble NASA has always had justifing risking people in space. The idea of deliberatly sending them to their deaths is ludacrus! Every politician who ever came near you would rush to lead the witch hunt to fire you and anyone who ever asked you a question. Any public interest in the project would immediatly turn to revulsion at such a suggestion. The whole concept of interstallar flight would be off limits for years, even if someone else came up with a two way idea. > >> * Use the interstellar medium > > > >We have no real idea how to, or for that matter know whats out there to use. > > There is just too little, unless we can scoop an area with a 1000 km radius. Again we don't even know whats out their, but it does seem unlikly that it will be able to help us any. > >> * Power from installations at Solar system > > > >Beamed power or fuel launchers have the advantage of offloading the need to > >carry the heavy fuel (and power systems) with the ship. That improves the > >ships power to weight ration significantly. But the systems are difficult to > >do, limit range, and don't seem to help us to slow down. > > Also they have a not so good efficiency. (A big part of the beam just flies > along the ship without being used.) Thats true of beamed power, not launched fuel. > >> 3. Gravity on board > > > >I think the idea I came up with for a multi segmeny hab ring is the best. We > >need gravity for the crew, and the rotating hab segments will allow it to > >adapt to changing thrust directions. Unless the ship can operate under > >continuous thrust for the full flight. This seem best. > > You would always need the rotating rings, because in the time that you spend > at TC you don't have acceleration because of engine-thrust. True. I guess my had ring idea covers all requirement well enough to be assumed in a ship. > >> 4. Mission composition > > > >Given the size the main ship must be, I don't think we could afford 2. Which > >is a pity from a safty standpoint. A robotic pathfinder would be a good idea > >if it would work, but I'm dubious. > > > >A suply ship sounds a little risky. How would you like to be waiting in the > >target system for the next 5 years groceries. > > The idea of supply ships is to send them first and wait for them to arrive > savely, unfortunately that would take 20 years from their launch. No a good > way for food. 20 year old rations? Kelly From popserver Wed Jan 10 05:04:25 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2930" "Wed" "10" "January" "1996" "00:17:02" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "64" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA03985 for ; Tue, 9 Jan 1996 15:16:04 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA03942 (5.67b/IDA-1.5 for ); Wed, 10 Jan 1996 00:16:55 +0100 Message-Id: <199601092316.AA03942@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Wed, 10 Jan 1996 00:17:02 +0100 Timothy replies to Kelly: >> I think that staging would not solve a more fundamental problem: Pressure >> One can see the engine as a force pressing on the back of the ship. We want >> a certain acceleration a. The heavier the ship gets, the bigger the force >> that is needed to get that acceleration (F=m*a). But assuming the backside >> of the ship stays about the same, the pressure (p=F/Area) gets bigger and >> bigger. --- > >Do you mean the thrust loads? If so we will need to take that into >consideration. But we can use some of the fuel or reaction mass as structure >(ice perhaps?) and the structure needed to carry the load shouldn't be a >major fraction of the fuel mass. I'm not sure of what you mean with thrust loads. What I meant was that the beams that connect the engine with the ship may not be able to stand the load. It's like you were pulling a very heavy cart with a sewing thread. For most metals the pull- or press-strength is about the same and in the magnitude of 4E8 N/m^2 You have a solid beam of iron (7.8E3 kg/m^3) with sizes 10x10x5000 metres. It would weigh 10*10*5000*7.8E3=3.9E9 kg Now you want to accelerate is with 9.8 m/s^2 you do that by equally excerting pressure at the 10x10 area. That would mean a pressure of (3.9E9*9.8)/(10*10)=3.8E8 N/m^2 As you can see the pressure is almost to is maximum and any unperfection will probably have caused it to snap earlier. I thought of a way to overcome this problem though, just add some (probably more than 10) extra engines. Then the load per engine could be less and so could the stresses. These extra engines should NOT be placed at the back (that would not change the problem) but along the side of it. >>I don't agree with you on that (yet?), I will expect an answer on >>my letter of 01-05 10:55. > >What letter? The ones in my inbox don't have that time? Maybe you have one of 6 hours earlier due to timezones, but I will send it to you again. >> >> * Power from installations at Solar system >> > >> >Beamed power or fuel launchers have the advantage of offloading the need >to >> >carry the heavy fuel (and power systems) with the ship. That improves the >> >ships power to weight ration significantly. But the systems are difficult >to >> >do, limit range, and don't seem to help us to slow down. >> >> Also they have a not so good efficiency. (A big part of the beam just flies >> along the ship without being used.) > >Thats true of beamed power, not launched fuel. The advantage of a lower ship:fuel ratio is that it needs less energy. If one decides to launch that fuel instead of adding it to the ship from the start, there is not much gain: Although the weight of launched fuel is less, there is a large extra amount of energy needed to launch that fuel. It follows from calculations that the total gain is not so big as you would have thought. But what you have added is a complicated launch method. Timothy From popserver Fri Jan 12 03:57:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["17239" "Thu" "11" "January" "1996" "21:30:51" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "382" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA14790 for ; Thu, 11 Jan 1996 18:32:33 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id VAA08095; Thu, 11 Jan 1996 21:30:51 -0500 Message-ID: <960111212801_88210828@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Thu, 11 Jan 1996 21:30:51 -0500 Zenon! I did get you letter but was going to try to shuffle the catagories around and see if I could come up with something. I will respond! Oh, I still say there is no significant difference between a suicide flight, and a flight where the crew are abandoned with enough supplies to last them their life. I am frankly shocked that you and Tim could seriously suggest such a horrific and ruthless option. Thats like sending a team to antartica, on a one way trip to the pole with no resuply and recovery runs! "Hey guys, go there, explore, radio back what you find, and here's 50 years supplies and parts for you to live out you life with." Timothy replies to Kelly: > > >> I think that staging would not solve a more fundamental problem: Pressure > >> One can see the engine as a force pressing on the back of the ship. We want > >> a certain acceleration a. The heavier the ship gets, the bigger the force > >> that is needed to get that acceleration (F=m*a). But assuming the backside > >> of the ship stays about the same, the pressure (p=F/Area) gets bigger and > >> bigger. --- > > > >Do you mean the thrust loads? If so we will need to take that into > >consideration. But we can use some of the fuel or reaction mass as structure > >(ice perhaps?) and the structure needed to carry the load shouldn't be a > >major fraction of the fuel mass. > > I'm not sure of what you mean with thrust loads. Thrust is the presure on the ship from the engines that shoves the craft along. > What I meant was that the beams that connect the engine with the ship may > not be able to stand the load. It's like you were pulling a very heavy cart > with a sewing thread. For most metals the pull- or press-strength is about > the same and in the magnitude of 4E8 N/m^2 > > You have a solid beam of iron (7.8E3 kg/m^3) with sizes 10x10x5000 metres. > It would weigh 10*10*5000*7.8E3=3.9E9 kg > Now you want to accelerate is with 9.8 m/s^2 you do that by equally > excerting pressure at the 10x10 area. > That would mean a pressure of (3.9E9*9.8)/(10*10)=3.8E8 N/m^2 > As you can see the pressure is almost to is maximum and any unperfection --- This really isnt a problem Tim. All large systems have to distribute their strructural loads amoung enough structure to get the job done. The shuttle tanks for example weight 30 tons, yet can carry about 750 tons of fuel at multiple G accelerations, and provide expensive structural bracing for the fources of the attached solid boosters and orbiter. Our starship design would be comparativly trivial. >-----These extra engines should NOT be placed at the back > (that would not change the problem) but along the side of it. Sorry they have to be at the back. Otherwise they would be blasting the sides of the ship. > >>I don't agree with you on that (yet?), I will expect an answer on > >>my letter of 01-05 10:55. > > > >What letter? The ones in my inbox don't have that time? I just got it, never saw it before thou. Responce below. > >> >> * Power from installations at Solar system > >> > > >> >Beamed power or fuel launchers have the advantage of offloading the need > >to > >> >carry the heavy fuel (and power systems) with the ship. That improves the > >> >ships power to weight ration significantly. But the systems are difficult > >to > >> >do, limit range, and don't seem to help us to slow down. > >> > >> Also they have a not so good efficiency. (A big part of the beam just flies > >> along the ship without being used.) > > > >Thats true of beamed power, not launched fuel. > > The advantage of a lower ship:fuel ratio is that it needs less energy. If > one decides to launch that fuel instead of adding it to the ship from the > start, there is not much gain: Although the weight of launched fuel is less, > there is a large extra amount of energy needed to launch that fuel. > It follows from calculations that the total gain is not so big as you would > have thought. But what you have added is a complicated launch method. You keep missing the point that the ship doesn't need to be generating the power to accellerate the fuel. Tus it would need as much fuel for power. The over all energy expenditure of the systems is irrelavant. ============================= the lost letter =========== > Timoty replies to Kelly: > > >Fusion is an extreamly usefull general purpose technology. Anti-matter is > >far less so, and far more dangerous on the scale we would need. I wouldn't > >expect a lot of anti-mater ships in 50 years. > > You shouldn't see anti-matter as a fuel, but more as efficient energy > storage. Why is anti-matter not a fuel? Because we have to make it. > Coparing these two is like comparing a petrol car with an electric car. The > energy for an electric car has to come from other fuels. Although the weight > advantage with electric cars may not be evident yet there are other > advantages. One of the advantages is the independancy of the origin of the > fuel source. If it is fusion, fission or solar energy all are easely > converted to electric energy which is relative easy to handle. > So what car-batteries are for us now, anti-matter will be for fast spacevessels. What electric cars are now, is exotic impractical and dangerous (and oddly not particularly clean). Fusion fuel can be mined and stored fairly easily. Anti-mater is a nightmare to hold in quantity, and in our case difficult to use efficently. Again certainly beyond the tech of 2050. > >Oh, that would be beyond the resources and tech of the project. Also it seem > >a waste of time. Sort of novelty project for the record books. With no > >practical reason to stay perminently there the bases would be prefab ghost > >towns. Future missions to other solar systems would have to be based out of > >dynamic, growing, large scale, civilizations. Not out of a staging camp in > >the middle of nowhere. > > If it really is to get a entry in the record books and not much more that > would really be a shame of all resources. If people really want to do that, > I see the end of humanity near. Would you say the same about missions to the Earths poles? Fairly common and trivially cheap compared to this. A far, far more habitable environment than any alien planet is likly to offer. Yet no one has attempted to colonize Antartica. What would be the point? > About growing civilizations, I don't think that western cultures will expand > that much. In the US the birthrate is 2.05 per female, in Europe it's about > 1.8. So that would mean that population will decrease. > The mean reason that Earth's population is still increasing are the less > developed countries which have birthrates of 4 to 7. > I think that families in developed countries have less children because of > the care these children need (financial but also social/tutorial). > So this means that we probably never need to go to other places. Well I wasn't refering to growing in population (and actually you have all thouse birth rates to high), but growing technically, economically, etc... Obviously games like these are only for the very rich. > But if we want to explore and discover new places we may want outposts at > many places. So building small colonies would not be that crazy then. > These colonies would have two purposes, the outpost and a research function. > There would probably many researchers that like to check a foreign planet. A base I could agree to, but not a colony. They are too isolated and to dependant on that long supply line from earth. Thou they are rich in resorces (ore and fuel). Without the infastructure and personel to exploit it, thats irrelavant. Without something big to attract major numbers of people here (which you seem to agree) they would stay to smal to be an independant population. At best they'ld be people rotated back to earth with the next supply run. I keep coming back to the isolation. It takes to long to get a ship out there and back, and costs too much to send it for this to be a colony or even a sustainable outpost. > >Forever? Do you expect earth to keep funding these people in this base > >forever? With continuous supply flights from sol to keep them going? We > >couldn't even keep the moon program going for more than a few months after it > >planted its flag. > > After some time they could have build a small colony with all facilities > needed to live and work. The energy they need comes from TC itself. So Earth > would need funding them, but since they have build a "nice" place in the > middle of an interesting place they may be interested to hear something of them. > You may argue that building a colony is difficult in an alien environment, > but by that time we will have some experience in building things on the Moon > or Mars. Moon and mars are also unsuitable (low gravity). More important you keep expecting them to live off the land. Thats like droping a hundred people in kansas with a small truck load of gear each, allow no trade with the out side, and expect them to build a ultra-modern city. Not likely. > >> Why don't you expect them to do that? I still don't see that as suicide, > >> they can live perfectly healthy lives. > > > >Thats like condeming somone to spend the rest of their lives in an > >apartment/shoping mall! Good researchers will want to retire or go on to > >other projects. Not sit around in a worn out ship, in the middle of nowhere, > >with nothing to do. > > Other projects, they have all the choice they could have. Who's going to > tell them that they cannot do what they want. The only limits are the ones > of themselves. Again you seem to be assuming they have tremendous resources of equipment and time. They would be extreamly limited, and given the dangerous nature of their mission. They are probably going to be losing stuff (people and equipment) fairly quickly. Without Earth benificent supply runs. They are going to be in bad shape fairly soon. > The people going there aren't the people who really want to retire, these > are people that are born for exploration and research. (They really exist) > My guess is that they wouldn't sit all the time in some ship or compartment, > but that they would allow themselves to go to the planets surface (in > spacesuits). Most of them will never be able to go to the planets. After a while none of them will be able to as the equipment runs out. If they have to plan on a long stay, they'll have to curtail exploration fairly quickly in order to save the equip for more practical uses. > >Sorry, no. In large projects like this the sum of the parts is the lowest > >common denominator of everyone. It becoming a big issue in the U.S. The > >more people you get on a project, the less energy and inovation is avalible. > > Things get bogged down, lost in committe misunderstanding, ecetera. Costs > >can go up to hundreds of times what a small tight group could do it for. > > And do you know why this happens, because everyone wants his own share and > no one is prepared to accept an idea of an other because that will mean a > loss of personal profit. No its more fundamental than that. Theirs just too many people. The more people the more corrdination efforts. For example I worked in the Space Station Freedom headquarters along with a few thousand other people. NONE of us actually worked on the space station. We worked to coordinate information between all the groups. The more people, the harder it is to keep everyone informed. On a big goverment project, everyone has to know what everyone else is doing. The more agencies, the more paths of interaction. Since governments tend to demand everything is monitored to the finest detail. The vast bulk (maybe 80%-90%) of the group effort is in meeting and reports to keep everyone else informed. > >Thats one of the reasons that over the last decade or two, NASA has been > >incapable of trying, or developing, cutting edge technologies or programs. > > Maybe even one country is too big? Certainly one buracracy is! > >> Exploration isn't much fun? What else drives people to such far places... > > > >Curiosity, greed, a chalenge, desire for fame or acomplishment. Exploration > >is generally horiobly uncomfortable and life threatening. But its very > >chalenging, and its atractive to know your one of the few to ever do > >something, know something, etc... Even if you know its killing you. > > Sorry, I had a more lossy idea about the word exploration than you did, I > meant approximately what you wrote. > > >Like an anthro professor my wife had. He loved studying aborigional tribes > >in the backwaters of the Amazon, but he frely admitted everyone who does it > >expect that they've paid with decades off their life expectancy. > > So that means a return trip won't be necessary. These people all wanted to come back. They wanted to go back out to the bush again, but not forever, and not to die. > >Since your dealing with radically differnt life forms. Its unlikely the old > >rules, or solutions, would hold. We mostly will be starting from scratch. > > After all, we have no experience with alien biospheres. > > I doubt if they are so radically different, all lifeforms have to abide the > laws of nature. Maybe some of them have found tricks that have not been > found on Earth but that is why we are going there. > And still if we know what doesn't work the chances of finding > something that does work are enlarged. Why not radically differnt? Life on earth is all based on a couple of basic chemical and anitomical tricks. There isn't anything special about those tricks. MANY others would work as well. I imagine most life out their will be radically different from that here, and may have a few times as long as Earth had to develop. > >We're in a serous bind. The tech we can expect in 50 years isn't enough for > >a T.C. flight. Or all but the most modest interstellar flights. NOr would > >they be that likely to be interested in footing a huge program. Yet if we > >back up the date by a hundred years we could be much more confident that they > >could do it, and do it affordably, but we wouldn't have any credible idea > >how! > > So maybe we should say "a priori" that certain techniques are > available. And discuss how and why these could be used. I suggested that a few months ago and got no interest. I suppose it moves this project from a serious attempt to figure out if we could do it in 2050. To a science fiction club. > >Put another way. Are we that likely to be so afraid of human extinction, > >that we'll rush to do such a project in 50 years? > > You can never tell :) people are worring about many things (like asteroids > colliding with Earth or the Asimov :)) > If humanity ever becomes extinct, it will be likely that it is not because > of natural disasters. Well nature is our worst enemy, but then we are very hard to kill. More to the point we could built fleets of O'Niel sized space colonies here for far less than this project. And they wouldn't have the resorce, access, and communication limits of a star colony. > >Oh certainly. The united states gets several million of them a year! But, > >another star doesn't offer much opportunity. It isolated, expensive, no > >markets to go to, few resorces that you can get at. No home world to go to > >on vacation to. Your very dependand on the supply line from Sol, and their > >for far less independant than you would be in a colony in Sol. > > You indeed can't go on vacation, and it probably never will have more than > 1000 inhabitants for the first 100 years. But as every place where people > live, they will adapt themselves and the environment. Not all people want to > become rich by selling stuff, a lot of them just want a place to life as > they like with the "sky" as the only limit. As I said before dependancy is > only a short time (if at all), once there is TC-light and gravity they can > grow food just as on Earth. So the first necessaries of life should not be > that difficult. I would say just the oposite. Life on a T.C. colony will be hard and very limited. The planets would be ignored, and the platform colony would need a lot of work to equip and maintain. They would be far more dependant and under the control of whoever runs the supply flights, then a similar colony in Sol space. > >Also, the kind of people we would send on such a ship. Would be the ellete > >that would have a lot of opportunity back home. The people who want a new > >start, wouldn't be sent on the ship. > > If you are 25 to 30 how sure can you be that you are a member of that elite. If you didn't already have the credientials,you wouldn't be offered a ride. (You would be stunned at the credentials NASA can require for astrounauts that only get to fly every yeear or three. On the other hand the turn over rate among the astronuate is pretty high. They are highly competative people. After they do this, they want new chalenges and get bored. > Also it doesn't have to be a new start but a first very defiant start. ?? Defiant of what? Defiannce doesn't work very well when you are dependant on others. From popserver Sat Jan 13 04:23:33 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["15236" "Sat" "13" "January" "1996" "01:42:17" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "293" "Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA07547 for ; Fri, 12 Jan 1996 16:41:15 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA08539 (5.67b/IDA-1.5 for ); Sat, 13 Jan 1996 01:42:11 +0100 Message-Id: <199601130042.AA08539@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Engineering Newsletter Date: Sat, 13 Jan 1996 01:42:17 +0100 Timothy replies to Kelly: >Oh, I still say there is no significant difference between a suicide flight, >and a flight where the crew are abandoned with enough supplies to last them >their life. I am frankly shocked that you and Tim could seriously suggest >such a horrific and ruthless option. Thats like sending a team to antartica, >on a one way trip to the pole with no resuply and recovery runs! "Hey guys, >go there, explore, radio back what you find, and here's 50 years supplies and >parts for you to live out you life with." Summarizing what I write in this letter: - We have to discuss what is necessary for a small colony. - You can't compare Antarctica with a new planet full of life. - We (or I) don't see it as dropping people without any regard, but as a well organized lifetime adventure. - Do things break down or get lost faster than one can repair or replace them? >This really isnt a problem Tim. All large systems have to distribute their >strructural loads amoung enough structure to get the job done. The shuttle >tanks for example weight 30 tons, yet can carry about 750 tons of fuel at >multiple G accelerations, and provide expensive structural bracing for the >fources of the attached solid boosters and orbiter. Our starship design >would be comparativly trivial. For these shuttle tanks the bottoms have the highest pressure while the top has a low pressure. (It could be left open, at least for the matter of pressure). So the weight of the tanks isn't the main clue but the size of the bottom is (assuming that every part of the bottom gets the same pressure). So a tank with a large bottom and the same weight has much less pressure at that bottom. (The total force stays the same, the surface gets bigger). So it would be wise to build the walls of the tanks thick at the bottom and thinner at the top. Also the welds are more likely to break at the bottom than at the top. What I'm trying to say is thus that the bottom part is most vulnerable, For the pressure at the bottom of the shuttle tanks, I can estimate: (assuming a 3.5 metre diametre of the bottom) (750+30 tons)*3g/(10 m^2)=830*3000=2.34E6 Pascal That means it is still 170 times less than the maximum pressure (about 4E8 Pa) So a large and heavy spaceship could be build but the load-surface should be large enough. The load surface is in fact equal to the surface of the ends of the beams that are connected to the engine. So taking long beams makes no difference, only taking thick beams does. Now where I was going to, if the ship becomes very large and the engine surface too small there isn't enough support-surface and the thing can't work. I realize of course that it takes a big ship to make these problems real. But how big will the support-surface of the engine for the Asimov be? 300 square metres (and engine with a radius of 10 metres) would mean that the Asimov could weigh about 3E10 kg. >>-----These extra engines should NOT be placed at the back >> (that would not change the problem) but along the side of it. > >Sorry they have to be at the back. Otherwise they would be blasting the >sides of the ship. Maybe a cone shaped vessel with the largest radius in front (anti-streamlined) would work. How had you planned to connect the torus-shaped hab-rail to the ship? The loads of a 100 metre arm should be multiplied by 100! >You keep missing the point that the ship doesn't need to be generating the >power to accellerate the fuel. Tus it would need as much fuel for power. > The over all energy expenditure of the systems is irrelavant. It is indeed clear to me that the ship does need less power, because it doesn't need to accelerate its own fuel. But if the over all expenditure of the system is irrelevant, why is it such a problem to accelerate a 1:1000000 ship:fuel combination? Such a ship would accelerate, it just needs a lot of engines (or one very powerful one). By the way I still don't see how you possibly can say that the amount of energy needed doesn't matter. (Yes, I know as long as we have no working method...) ============================================================================ >What electric cars are now, is exotic impractical and dangerous (and oddly >not particularly clean). Fusion fuel can be mined and stored fairly easily. > Anti-mater is a nightmare to hold in quantity, and in our case difficult to >use efficently. Again certainly beyond the tech of 2050. Yes, but so is 1E18 Watt during a few years. (You would create the same energy in a day as the Sun would in a second) OK, enough about anti-matter, I hope I've made clear what the advantages are if we can use this techniques savely. I accept that 2050 will not be ready for anti-matter but I also have strong doubts if any technique can handle the high power we need. What I expect to happen in the futere is that anti-matter will find its way at the same time that such enormous power finds it way. >Would you say the same about missions to the Earths poles? Fairly common and >trivially cheap compared to this. A far, far more habitable environment than >any alien planet is likly to offer. Yet no one has attempted to colonize >Antartica. What would be the point? On the poles you won't find a whole new planet full of life. If we indeed knew there were only a few boring planets with nothing more than dust, we would probably go somewhere else or not go at all. >A base I could agree to, but not a colony. They are too isolated and to >dependant on that long supply line from earth. Thou they are rich in >resorces (ore and fuel). Without the infastructure and personel to exploit >it, thats irrelavant. Without something big to attract major numbers of >people here (which you seem to agree) they would stay to smal to be an >independant population. At best they'ld be people rotated back to earth with >the next supply run. How many people should there be for an independant colony? I think 100 people should make a living possible. You indeed cannot expect large factories, but these aren't necessary since there are not many people. >> You may argue that building a colony is difficult in an alien environment, >> but by that time we will have some experience in building things on the >> Moon or Mars. > >Moon and mars are also unsuitable (low gravity). Yes, but they will have build structures for people working there for a few months. >More important you keep >expecting them to live off the land. Thats like droping a hundred people in >kansas with a small truck load of gear each, allow no trade with the out >side, and expect them to build a ultra-modern city. I'm not sure I know what Kansas is like, but surely if they had some habitation-modules from the year 2050 they could prosper. The modules have a self sustained climate, their only input is energy (from a small anti-matter-tank :) or just plain old solar-panels). Not only its climate is self-sustained but also vegetables and other food would would be grown. So now that you have your first-aid life support for one or two persons in say 300 cubic metres, you want something to do. OK in Kansas you probably could do nothing at all, but on TC you might want to get out. So what you need more is a bunch of basic construction machines and ore-extracters. These indeed are the things that use the most room and weigh the most. But they also could be used by more than one person. Now I'm interested to know what would be the minimal amount of machines to start at a reasonable level. (say the level of our current technology, meaning pentium-computers, Scanning microscopes etc.) I've not a good idea of what to take, do you? (Has this subject been discussed before?) - Life sustaining habitats. - Nano tech would be a great help for ore extracters - Machines to make simple metal, plastic forms. A lot of these machines we probably need on the Asimov during its 25 year mission, most computer won't last for 25 years continuous work. Taking with us a lot of reserve chips seems a bit too simplistic to me. (Even the food growing-machines are nessecary, eating 10 year old food all the time is yuck) >Again you seem to be assuming they have tremendous resources of equipment and >time. They would be extreamly limited, and given the dangerous nature of >their mission. They are probably going to be losing stuff (people and >equipment) fairly quickly. Without Earth benificent supply runs. They are >going to be in bad shape fairly soon. How fast are they loosing too much supply in a two-way mission? Even such a mission should stay there for about 10 years researching planets. They will be loosing stuff but if it goes in the rate you are predicting, then every mission is suicide. >> The people going there aren't the people who really want to retire, these >> are people that are born for exploration and research. (They really exist) >> My guess is that they wouldn't sit all the time in some ship or >> compartment, >> but that they would allow themselves to go to the planets surface (in >> spacesuits). > >Most of them will never be able to go to the planets. After a while none of >them will be able to as the equipment runs out. If they have to plan on a >long stay, they'll have to curtail exploration fairly quickly in order to >save the equip for more practical uses. That may indeed be the case, but a 10 year exploration with 100 people is hardly enough to do any real research of a complete solarsystem. Not to mention refueling or building complete beaming-arrays (only advanced nano-tech or anti-matter might overcome that problem). >No its more fundamental than that. Theirs just too many people. The more >people the more corrdination efforts. For example I worked in the Space >Station Freedom headquarters along with a few thousand other people. NONE of >us actually worked on the space station. We worked to coordinate information >between all the groups. The more people, the harder it is to keep everyone >informed. On a big goverment project, everyone has to know what everyone >else is doing. The more agencies, the more paths of interaction. Since >governments tend to demand everything is monitored to the finest detail. The >vast bulk (maybe 80%-90%) of the group effort is in meeting and reports to >keep everyone else informed. What if everyone informed themselves? It's like the internet, people make information available, othera read it and if they don't agree, they discuss it with the author, after discussing they come to a common conclusion (if not, that's because of stubbornness) which is made public again. Also not all people need to know about everything in such a big project, there are many specialized groups, but they should not loose the survey of the project. >> Maybe even one country is too big? > >Certainly one buracracy is! Then there may be a big problem, because such a big project would need a lot of people. >These people all wanted to come back. They wanted to go back out to the bush >again, but not forever, and not to die. Going to the bush doesn't take 5 to 7 years plus 5+ years of preparation. I only wonder those people come back, do you know that? I can lively imagine that there are also people who want to stay simply because the find that special lifestyle so fascinating. >Why not radically differnt? Life on earth is all based on a couple of basic >chemical and anitomical tricks. There isn't anything special about those >tricks. MANY others would work as well. I imagine most life out their will >be radically different from that here, and may have a few times as long as >Earth had to develop. The main tricks are based on storing and retreiving energy in and from molecules, that energy comes from the sun or from planet-heat (vulcanos). Are there many easy reactions that can do that back and forth. (a cycle reaction is probably to unlikely) On Earth that reaction is H2O+CO2 <--> O2+CnHm by the use of sunlight. Then there are aerobic creatures, that rely on (I hope I'm right) Sulphur or phosphor oxides for energy, but that is a single way reaction, once the sulphuroxide is used it is not reused. Also this substance is not likely to be available in large quantities for several billion years. I'm not sure how many basic trick theres are, but I think it would be very likely that the alien creatures use oxigen and CnHm as main food. Assuming this basic trick, a lot of conditions are already set. And if the basic conditions are set, so are the creatures that spring from it. >I suggested that a few months ago and got no interest. I suppose it moves >this project from a serious attempt to figure out if we could do it in 2050. > To a science fiction club. Then we should end the discussion about engines with the conclusion that only exotic fuels and/or enormous powerstations could make the trip possible. The techniques needed are only in a early theoretical stage and the size of what is necessary is (almost) beyond imagination and reasonabless. >> You can never tell :) people are worring about many things (like asteroids >> colliding with Earth or the Asimov :)) >> If humanity ever becomes extinct, it will be likely that it is not because >> of natural disasters. > >Well nature is our worst enemy, but then we are very hard to kill. Even on a planet 10 ly away? >More to the point we could built fleets of O'Niel sized space colonies here >for far less than this project. And they wouldn't have the resorce, access, >and communication limits of a star colony. You say these colonies are dependant on Earth, what if such a disaster happens, then they won't have much resources any more. >I would say just the oposite. Life on a T.C. colony will be hard and very >limited. The planets would be ignored, and the platform colony would need a >lot of work to equip and maintain. They would be far more dependant and >under the control of whoever runs the supply flights, then a similar colony >in Sol space. At sol there can't be planet based colonies because of the wrong gravity. (only Venus has a comparable g but it's a bit hot out there) You keep saying that it takes a lot of effort to keep the colony working, I wonder if that is true: Do you need to repair a lot in your house? (not a personal question) OK, a house on a barren planet would be different, but I cannot believe that everyone is constantly busy repairing things. >If you didn't already have the credientials,you wouldn't be offered a ride. > (You would be stunned at the credentials NASA can require for astrounauts >that only get to fly every yeear or three. On the other hand the turn over >rate among the astronuate is pretty high. They are highly competative >people. After they do this, they want new chalenges and get bored. Probably the normal astronauts are suited for such a trip. If they indeed want new challanges every few years, they are probably on the wrong trip. This trip is a carreer for life, even if you make it a two-way trip. >> Also it doesn't have to be a new start but a first very defiant start. > >?? Defiant of what? Defiannce doesn't work very well when you are dependant >on others. I think I meant challenging, those damn dictionaries.. Timothy From popserver Sat Jan 13 04:23:43 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1324" "Fri" "12" "January" "1996" "19:57:30" "-0500" "David Levine" "David@interworld.com" nil "34" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id QAA08679 for ; Fri, 12 Jan 1996 16:57:06 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.1 ID# 0-11464) with SMTP id AAA47; Fri, 12 Jan 1996 20:01:27 -0500 Message-ID: <30F7037A.DFD@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <199601130042.AA08539@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Fri, 12 Jan 1996 19:57:30 -0500 Just a quick note: Many people seem to be saying "What's the point of going there? We don't know for sure that there's anything interesting, and this is going to be hellishly expensive, if it's even possible." If this is going through anybody's mind, please remember that this is a thought experiment. We're trying to decide how we could go to the stars, if we wanted to. Yes, right now we probably don't want to. But assume we did. Assume that several planets have been detected at our target star, and spectral analysis even reveals the presence of chlorophyll, or some other definite indicator of the existance of life of some kind. Of course, if such a situation arose, we probably WOULD try to get something out there ASAP... but it would most likely be an unmanned probe. And while I think everyone agrees this would be a more sensible course of action, it's not as inherently interesting as a manned mission. And unmanned missions have been designed many times before. Manned missions have only been looked at sporadically. So let's assume that there is some reason to send people as well. I'll turn this "excuse" over to someone else... Anyway, remember: this is a thought experiment. Why we are going is not as important as HOW we are going - is it possible, and if so, how could it be done? -David From popserver Sat Jan 13 18:04:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1273" "Sat" "13" "January" "1996" "15:49:08" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "29" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA08852 for ; Sat, 13 Jan 1996 06:47:58 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA14525 (5.67b/IDA-1.5 for ); Sat, 13 Jan 1996 15:49:00 +0100 Message-Id: <199601131449.AA14525@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Sat, 13 Jan 1996 15:49:08 +0100 Timothy replies to David: >And while I think everyone agrees this would be a more >sensible course of action, it's not as inherently >interesting as a manned mission. And unmanned >missions have been designed many times before. Manned >missions have only been looked at sporadically. An unmanned mission has two possibilities, a not very extended survey of TC using technology of today. Or a more extended survey using the benefits of complicated AI. But since we don't know how fast AI will develop, we cannot say a lot of senseful things about it. >Anyway, remember: this is a thought experiment. Why >we are going is not as important as HOW we are going - is >it possible, and if so, how could it be done? Yes I know that the how aspect is most important but the reasons for discussing the WHY-aspect were: - A one-way trip would be much easier than a two-way trip. - The purpose of the trip has influence on the kind of crew and the load, which in turn may have influence on the design of the ship. - At the moment we are a bit in an impasse as for propulsion methods. - We wanted to know where possible fundings could come from. - Personally I thought it was an interesting question. Certainly while some of us don't agree with each other at all. Timothy From popserver Sun Jan 14 03:17:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7815" "Sat" "13" "January" "1996" "19:51:11" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "149" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA12586 for ; Sat, 13 Jan 1996 17:49:52 -0800 (PST) Received: by maroon.tc.umn.edu; Sat, 13 Jan 96 19:51:12 -0600 In-Reply-To: <199601130042.AA08539@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Sat, 13 Jan 1996 19:51:11 -0600 (CST) Kevin wishes to interrupt: > Timothy replies to Kelly: > > >Oh, I still say there is no significant difference between a suicide flight, > >and a flight where the crew are abandoned with enough supplies to last them > >their life. I am frankly shocked that you and Tim could seriously suggest > >such a horrific and ruthless option. Thats like sending a team to antartica, > >on a one way trip to the pole with no resuply and recovery runs! "Hey guys, > >go there, explore, radio back what you find, and here's 50 years supplies and > >parts for you to live out you life with." > > Summarizing what I write in this letter: > - We have to discuss what is necessary for a small colony. > - You can't compare Antarctica with a new planet full of life. > - We (or I) don't see it as dropping people without any regard, but as a well > organized lifetime adventure. > - Do things break down or get lost faster than one can repair or replace them? Okay, Okay, I think we've all heard enough of this argument. Neither of you is going to change the other's mind. If all we can do is figure out how to send a one-way mission, then I think we can assume that it will never be used until someone comes up with a valid reason to send so many people off on a no-return mission. What's a good reason? Why, one that would attract enough qualified (intelectually and psychologically) volunteers of course. I think we all agree that it would be a good _idea_ to have a return flight, The question, is whether it is possible or not. i think it is, A one-way mission would only be sent in the direst of planetary emergencies (sun going nova, hostile aliens etc.) > >What electric cars are now, is exotic impractical and dangerous (and oddly > >not particularly clean). Fusion fuel can be mined and stored fairly easily. > > Anti-mater is a nightmare to hold in quantity, and in our case difficult to > >use efficently. Again certainly beyond the tech of 2050. > > Yes, but so is 1E18 Watt during a few years. (You would create the same > energy in a day as the Sun would in a second) Impractical and expensive, yes, but there are no tech dificulties. you would not be "creating" the energy, but only re-directing a tiny fraction of the sun's output. I would say it thusly "you would be using 1/3600 of the suns total output for a period of 2 years" After that, the energy could be used right here in Sol System for any other project that was desired. > OK, enough about anti-matter, I hope I've made clear what the advantages are > if we can use this techniques savely. I accept that 2050 will not be ready > for anti-matter but I also have strong doubts if any technique can handle > the high power we need. What I expect to happen in the futere is that > anti-matter will find its way at the same time that such enormous power > finds it way. > As to anti-matter and large energy requirements -- I think it would be far more useful to figure out how we can send the most mass for the least energy. Tim, if you want to postulate anti-matter, go ahead. give some rough idea of how you intend to make it and store it, and then let us argue about when we might expect it. I for one, will postulate beamed energy, and once I have a workable system, I will go about estimating the size and manufacturing time of the requesite array. same with Kelly's design, come up with a viable method of stopping and tell us how long it would take to come up with the tech. (or lhow long it will take to pre-load the decell track) Then when we have several methods, we can rank them according to speed of travel, tech level, and other factors, to come up with a viable method. Tim, i have a question for you regarding anti-matter, how do you intend to direct the "exhaust"? as I see it, anti-hydrogen would combine with normal hydrogen (scooped?) and this would result in a burst of Gamma rays in _all_ directions. how will you harness the momentum of these photons? assuming you can make and store the anti-hydrogen, how many Kg of anti-matter would you need to get to the target star? do we carry the return trip fuel with us? or try to make it from the target? if we are going to make it, what percentage of energy can be turned into anti-matter? (and you can't assum 100% eff. either, or then I can assume 100% eff. solar arrays and microwave converters ;) ) and where does the energy come from if you intend to make it? (one idea for storage of anti-matter, start with anti-hydrogen,made from slamming high-speed protons into a stationary target, and use fusion to work your way up to anti-iron does anti-matter give energy when it fuses with anti matter? i think it must. when you have a quantity of anti-iron, magnetize it and your storage problems are solved. many of these technologies probably won't be avail until 2250 AD :( ) > > I'm not sure I know what Kansas is like, but surely if they had some > habitation-modules from the year 2050 they could prosper. > The modules have a self sustained climate, their only input is energy (from > a small anti-matter-tank :) or just plain old solar-panels). Not only its > climate is self-sustained but also vegetables and other food would would be > grown. So now that you have your first-aid life support for one or two > persons in say 300 cubic metres, you want something to do. OK in Kansas you > probably could do nothing at all, but on TC you might want to get out. So ^^^^^^^^^^^^^^^^^ I thought you said you didn't know what Kansas was like. ;) (for information, it is totally flat, totally farming, and totally boring) > That may indeed be the case, but a 10 year exploration with 100 people is > hardly enough to do any real research of a complete solarsystem. Not to > mention refueling or building complete beaming-arrays (only advanced > nano-tech or anti-matter might overcome that problem). > One of the implicit assumptions I'm going to use is that some form of self-replicating machinery is possible. not nano-tech, and not self-directed either. I'm assuming that a robot can be made that can make a copy of itself given: premade circuit board (pentium level motherboard with cameras and wireless modems) and ready made ores. that is, some other machine refines the ores and gives our robot "ingots" of aluminum or silicon or whatever else it needs. The robot needs to do the following autonomuos tasks: 1) shape metal into any shape (most NC millers can do this today) 2) make a 1 meter by 1 meter solar cell from a solid ingot of silicon and proper doping materials (they work in vacumn, so much bulky equipment won't be needed 3) scoop or mine ore and bring it to a central location 4) wind motors, connect wires and other tasks required to make a copy of itself (note, while theoretically, one robot could make a copy of itself, in pactice, many would be assigned the task of turning out more robots A Semi-autonomous computer would direct all the robots, while humans would be available for debugging, and initial set-up. an ore processing machine will be required as well as constant oversight by one or more crew. these would then be able to first, turn out many copies of themselves, and then secondly, they could begin turning out the hectares of solar panels needed for the maser transmitters. the same system would work in Sol, as would work in TC This would solve the problem of super-large collecting arrays, by allowing geometric growth of the machinery needed to manufacture it. Kevin who _makes_ glass beads, but doesn't brag about it in off topic groups ;) just kidding Ric. From popserver Sun Jan 14 18:57:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7606" "Sun" "14" "January" "1996" "19:53:55" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "151" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA28129 for ; Sun, 14 Jan 1996 10:53:52 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA00771 (5.67b/IDA-1.5 for ); Sun, 14 Jan 1996 19:53:37 +0100 Message-Id: <199601141853.AA00771@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 19:53:55 +0100 Timothy replies to Kevin: >Okay, Okay, I think we've all heard enough of this argument. Neither of >you is going to change the other's mind. If all we can do is figure out >how to send a one-way mission, then I think we can assume that it will >never be used until someone comes up with a valid reason to send so many >people off on a no-return mission. What's a good reason? Why, one that >would attract enough qualified (intelectually and psychologically) >volunteers of course. I think we all agree that it would be a good >_idea_ to have a return flight, The question, is whether it is possible >or not. i think it is, A one-way mission would only be sent in the >direst of planetary emergencies (sun going nova, hostile aliens etc.) You shouldn't say that neither one is changing their mind. I'm certainly not argueing to enforce my ideas on those of Kelly, I'm trying to figure out why we do so fundamentally disagree. Now after a few letters, I think it is getting clearer were our differences are. If you don't like to read these discussions that's fine, but I sometimes have the idea that discussions are too easely stopped, so that in the end both (or more) members still disagree and that means that the whole discussion was done for nothing. >boost colony (ship/worlds) to other systems?> Probably not, the Sun would have grown too large before you could use its nova. I think the increase of the Sun's radiation will not be that significant. >Impractical and expensive, yes, but there are no tech dificulties. you >would not be "creating" the energy, but only re-directing a tiny fraction >of the sun's output. I would say it thusly "you would be using 1/3600 of >the suns total output for a period of 2 years" After that, the energy >could be used right here in Sol System for any other project that was >desired. I'm sorry, I'm not sure how I got to the numbers but what I wrote between braces is totally wrong, you would need about 1/(1E8) part of the Sun's total output. Meaning a solar panel with a 1000 kilometre radius near Earth. >As to anti-matter and large energy requirements -- I think it would be >far more useful to figure out how we can send the most mass for the least >energy. That would always be anti-matter or a beam that is very tight. >Tim, i have a question for you regarding anti-matter, how do you intend >to direct the "exhaust"? as I see it, anti-hydrogen would combine with >normal hydrogen (scooped?) and this would result in a burst of Gamma rays >in _all_ directions. how will you harness the momentum of these photons? >assuming you can make and store the anti-hydrogen, how many Kg of >anti-matter would you need to get to the target star? do we carry the >return trip fuel with us? or try to make it from the target? if we are >going to make it, what percentage of energy can be turned into >anti-matter? (and you can't assum 100% eff. either, or then I can assume >100% eff. solar arrays and microwave converters ;) ) and where does the >energy come from if you intend to make it? I haven't a complete oversight, but can tell you what I have in mind: 1. Matter is injected by matter, so that the photons collide with normal matter. This matter is heated and will escape at the place of the lowest pressure, the backside. This anti-matter engine needs more matter than antimatter. (I think in this case the comparison is big with chemical or fusion engines) 2. When an electron and anti-electron collide from almost rest, then 2 photons of 511 KeV (2400 nm) are formed, so this means that photons of resonable equally wavelength are created. So that would allow some kind of mirror to reflect them to the back. To be honest sometimes there are 3 or more photons formed with a total energy of 1022 KeV but all have different wavelengths. Now the problem is how to get only (anti)electrons and no protons or other bigger particles. I haven't an aswer to that, so for now this method will not work. You also ask how efficient it will be, that is hard for me to estimate, but like most engines it has to be efficient otherwise it will melt away. This seems like an easy way out, but I think it is true. So what it is important that the products of the antimatter reaction are all discarded and not absorbed in the engine. If the end-products are controlable this may not be too hard. >(one idea for storage of anti-matter, start with anti-hydrogen,made from >slamming high-speed protons into a stationary target, and use fusion to work >your way up to anti-iron does anti-matter give energy when it fuses >with anti matter? i think it must. when you have a quantity of anti-iron, >magnetize it and your storage problems are solved. many of these >technologies probably won't be avail until 2250 AD :( ) You could see anti-matter just as ordinary matter. All physic laws that are valid for matter do hold for anti-matter. Thus fusion would work. In fact Hydrogen is also a metal, it just has a very low melting point, I don't know however what its magnetic properties are. Also all materials have magnetic properties, though most don't have such a strong and autonomic fields as iron. So all materials will be attracted to or repelled from a magnetic field only some much more than others. >I thought you said you didn't know what Kansas was like. ;) >(for information, it is totally flat, totally farming, and totally boring) I had some feeling about what it should be like... >One of the implicit assumptions I'm going to use is that some form of >self-replicating machinery is possible. not nano-tech, and not >self-directed either. I'm assuming that a robot can be made that can >make a copy of itself given: premade circuit board (pentium level >motherboard with cameras and wireless modems) and ready made ores. that is, >some other machine refines the ores and gives our robot "ingots" of >aluminum or silicon or whatever else it needs. >The robot needs to do the following autonomuos tasks: I like the idea about such robots, especially because you could design them to build habitat units, or is that too difficult? >1) shape metal into any shape (most NC millers can do this today) What does NC mean? >2) make a 1 meter by 1 meter solar cell from a solid ingot of silicon and >proper doping materials (they work in vacumn, so much bulky equipment >won't be needed Even if needed (because of dust attracted and distributed by the ore-extracters) these vacuum pumps should not be that bulky. >these would then be able to first, turn out many copies of themselves, >and then secondly, they could begin turning out the hectares of solar >panels needed for the maser transmitters. the same system would work in >Sol, as would work in TC That would mean roughly 1E8 hectares, or about 3 hectares per second if you want to do it in 10 years :| The 1E7 masers would need to be build by robots too! This may need more complicate fabricating processes than solarcels. How much work can one robot unit do? Say 1m^2/second. So that means about 3E4 robots are needed. How long would one robot need to replicate itself? Say 3 days. Using exponetial growth: 2^T=3E4 --> T=173 --> 3*T=519 days needed to make 3E4 robots. If I use these numbers your plan could succeed. But are they realistic? 3 hectares per second seem so much. (You could really see it grow) Just a note: Would super conductors be any use to us? In free-space (not near a Sun) the temperatures are ideal for super conductors. Timothy From popserver Sun Jan 14 19:07:17 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1095" "Sun" "14" "January" "1996" "20:04:51" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "24" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA28617 for ; Sun, 14 Jan 1996 11:03:27 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA01538 (5.67b/IDA-1.5 for ); Sun, 14 Jan 1996 20:04:42 +0100 Message-Id: <199601141904.AA01538@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 20:04:51 +0100 Timothy replies to David: >I'm sorry, Timothy - I didn't make myself clear enough. >All I meant was that it seemed like every now and then >people were thinking "Why, really, are we doing this >when we're not even sure of the reason for the trip... >We haven't even explored our own solar system yet..." >or any number of other lines of thought. I just didn't >want people too discouraged. Of COURSE it's an interesting >question, and I certainly realize the impact a one- or >two-way trip would have on the mission. I guess all I'm >really saying is that we should pick some reason for >going (even if it means deciding between several possibilities >at random), stick with it and say "How would we do the >trip assuming THIS is the reason we're going?" and not >worry too much about why that particular reason is the one >chosen. OK, I was never assuming we would not go, I see it more as a reality that we would go, I only have doubts about the date. (2050 seems to near) I haven't really noticed others thinking different from me. I'm wondering who gave you that idea... Greetings Tim From popserver Sun Jan 14 21:56:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9126" "Sun" "14" "January" "1996" "15:23:13" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "200" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA05387 for ; Sun, 14 Jan 1996 13:21:53 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 14 Jan 96 15:23:13 -0600 In-Reply-To: <199601141853.AA00771@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 15:23:13 -0600 (CST) On Sun, 14 Jan 1996, Timothy van der Linden wrote: > Timothy replies to Kevin: > > >Okay, Okay, I think we've all heard enough of this argument. Neither of > >you is going to change the other's mind. If all we can do is figure out > > You shouldn't say that neither one is changing their mind. I'm certainly not > argueing to enforce my ideas on those of Kelly, I'm trying to figure out why > we do so fundamentally disagree. Now after a few letters, I think it is > getting clearer were our differences are. > If you don't like to read these discussions that's fine, but I sometimes > have the idea that discussions are too easely stopped, so that in the end > both (or more) members still disagree and that means that the whole > discussion was done for nothing. Oh, you two can go on argueing if you want to, don't let me stop you. I just thought that the ground had been covered many times before in finest detail. I did not realize that you were still confused as to what Kelly meant. i suppose that's my own fault for thinking that all members of this group speak english with perfect understanding (typical american attitude i know, but at least I can admit my mistake) I'm just glad this dicussion isn't taking place in Dutch or Polish > >Impractical and expensive, yes, but there are no tech dificulties. you > >would not be "creating" the energy, but only re-directing a tiny fraction > >of the sun's output. I would say it thusly "you would be using 1/3600 of > >the suns total output for a period of 2 years" After that, the energy > >could be used right here in Sol System for any other project that was > >desired. > > I'm sorry, I'm not sure how I got to the numbers but what I wrote between > braces is totally wrong, you would need about 1/(1E8) part of the Sun's > total output. > Meaning a solar panel with a 1000 kilometre radius near Earth. and a lot smaller if you could put in orbit at mercury's distance. > > >As to anti-matter and large energy requirements -- I think it would be > >far more useful to figure out how we can send the most mass for the least > >energy. > > That would always be anti-matter or a beam that is very tight. i don't agree, that's true only if you want to do it in a man's lifetime. if you are willing to accept a lower speed, then you can do the trip with a _lot_ less energy. > > >anti-matter would you need to get to the target star? do we carry the > >return trip fuel with us? or try to make it from the target? if we are > >going to make it, what percentage of energy can be turned into > >anti-matter? (and you can't assum 100% eff. either, or then I can assume > >100% eff. solar arrays and microwave converters ;) ) and where does the > >energy come from if you intend to make it? > > I haven't a complete oversight, but can tell you what I have in mind: > > 1. Matter is injected by matter, so that the photons collide with normal > matter. This matter is heated and will escape at the place of the lowest > pressure, the backside. This anti-matter engine needs more matter than > antimatter. > (I think in this case the comparison is big with chemical or fusion engines) > > 2. When an electron and anti-electron collide from almost rest, then 2 > photons of 511 KeV (2400 nm) are formed, so this means that photons of > resonable equally wavelength are created. So that would allow some kind of > mirror to reflect them to the back. To be honest sometimes there are 3 or > more photons formed with a total energy of 1022 KeV but all have different > wavelengths. > Now the problem is how to get only (anti)electrons and no protons or other > bigger particles. I haven't an aswer to that, so for now this method will > not work. > > You also ask how efficient it will be, that is hard for me to estimate, but > like most engines it has to be efficient otherwise it will melt away. This > seems like an easy way out, but I think it is true. So what it is important > that the products of the antimatter reaction are all discarded and not > absorbed in the engine. If the end-products are controlable this may not be > too hard. I meant by eff. Question, "what will the eff. of energy to antimatter conversion be?" or How many kilowatts does it take to make a gram of anti-matter? > > >(one idea for storage of anti-matter, start with anti-hydrogen,made from > >slamming high-speed protons into a stationary target, and use fusion to work > >your way up to anti-iron does anti-matter give energy when it fuses > >with anti matter? i think it must. when you have a quantity of anti-iron, > >magnetize it and your storage problems are solved. many of these > >technologies probably won't be avail until 2250 AD :( ) > > You could see anti-matter just as ordinary matter. All physic laws that are > valid for matter do hold for anti-matter. Thus fusion would work. > In fact Hydrogen is also a metal, it just has a very low melting point, I only if you put it under a hellish pressure. > don't know however what its magnetic properties are. > Also all materials have magnetic properties, though most don't have such a > strong and autonomic fields as iron. So all materials will be attracted to > or repelled from a magnetic field only some much more than others. > Actually, if we could get any respectable solid at all, like Li maybe, then we could give it an electricall charge and keep it suspended that way > >One of the implicit assumptions I'm going to use is that some form of > >self-replicating machinery is possible. not nano-tech, and not > >self-directed either. I'm assuming that a robot can be made that can > >make a copy of itself given: premade circuit board (pentium level > >motherboard with cameras and wireless modems) and ready made ores. that is, > >some other machine refines the ores and gives our robot "ingots" of > >aluminum or silicon or whatever else it needs. > >The robot needs to do the following autonomuos tasks: > > I like the idea about such robots, especially because you could design them > to build habitat units, or is that too difficult? no, I think that would be possible. > > >1) shape metal into any shape (most NC millers can do this today) > > What does NC mean? > Numerically Controlled, old fashioned term for computer controlled > >2) make a 1 meter by 1 meter solar cell from a solid ingot of silicon and > >proper doping materials (they work in vacumn, so much bulky equipment > >won't be needed > > Even if needed (because of dust attracted and distributed by the > ore-extracters) these vacuum pumps should not be that bulky. > > >these would then be able to first, turn out many copies of themselves, > >and then secondly, they could begin turning out the hectares of solar > >panels needed for the maser transmitters. the same system would work in > >Sol, as would work in TC > > That would mean roughly 1E8 hectares, or about 3 hectares per second if you > want to do it in 10 years :| > The 1E7 masers would need to be build by robots too! This may need more > complicate fabricating processes than solarcels. > > How much work can one robot unit do? Say 1m^2/second. > So that means about 3E4 robots are needed. > How long would one robot need to replicate itself? Say 3 days. > Using exponetial growth: 2^T=3E4 --> T=173 --> 3*T=519 days needed to make > 3E4 robots. Tim, i think you have a little problem here. 2^173= 1.19 E+52 robots =8^O In fact, I'm having trouble following where some of your numbers come from. assuming that your 1000 Km radius solar array is correct, I get (1000 * 1000)^2 *PI() = 3.14 E+12 m^2 of solar cells i think your estimate of solar cell production is way too liberal, I say 1 m^2/day is more likely. so now we need 8.6 E08 robots to do the job in ten years I think your three day replication estimate is good. using exponential growth, I get 2^T=8.6 E08 T=29 days 3 * T =89 days thats if we start with one robot. I think we would probably start with a 1000. if we let reproduction continue for 100 days ( nice round number) we'd have 8.59 E09 robots, and at the lesuirely rate of 1 m^2/day, we could build the entire solar array in 365 days. 100 robots could work on each maser transmitter, and all of them could be built in a month. we'd still have plenty of robots left over to build habitats, mine fusion fuel, or whatever other job we needed done. with that many pentium level processers, the resultant computer power would be staggering! Now, as Kelly says, when you get this many "Grunts", the job of the top boss becomes more and more difficult. but with several layers of "middle managment" computers, I think it would be doable ( although, maybe not at the speed I was reffering to > Just a note: Would super conductors be any use to us? In free-space (not > near a Sun) the temperatures are ideal for super conductors. yeah, I think we are going to need that technology in many areas. Computer circuitry, accelerator coils, fusion containment coils anywhere you have a lot of energy, and no way to remove the heat. Kevin From popserver Mon Jan 15 03:24:18 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2731" "Sun" "14" "January" "1996" "22:07:33" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "60" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA21351 for ; Sun, 14 Jan 1996 19:09:49 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id WAA29530; Sun, 14 Jan 1996 22:07:33 -0500 Message-ID: <960114220732_116630037@mail04.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 22:07:33 -0500 > Kevin wishes to interrupt: > > > Timothy replies to Kelly: ---- > --- same with Kelly's > design, come up with a viable method of stopping and tell us how long it > would take to come up with the tech. (or lhow long it will take to > pre-load the decell track) Then when we have several methods, > we can rank them according to speed of travel, tech level, and other > factors, to come up with a viable method. Of the two ideas I came up with (launched fuel and stages fusion rocket) they both are stuck with using stored on-board fuel for deceleration. No solid numbers yet but it looks like 20% to MAYBE 30% is doable. In more detail: For a fuel laucher based systems the ship takes off with a ful load of decel fuel and accelerates up the accelleration track wich is pre loaded with fuel. Its maximum speed is limited by how far they launcher can accuratly launch the fuel. I.E. how far from the launcher does the fuel become so dispersed that the ship can't scoop up enough for its needs. Anyway. The ship leaves sol with its decel fuel. Coasts to a star thats close enough (T.C. would not be close enough, so I'm assuming Alpha C or something else in the 4-6 ly range), then Decelerates with the onboard fuel. For the return flight, it can eiather accelerate with stored fuel and decel into sol using a Sol fuel launcher provided decel track. Or they could, maybe, biuld a fuel launcher atthe target system. This would allow that ship, and subsequent ships, to make the flight at speeds not limited by on-board fuel limitations. Possibly at much higher speeds. A multi stage ship is theoretically limited by how many stages you can get. But I think the specific impulse of the system will give an upper practical limit. Returning could be harder since you won't have all the stages. Tim I think the central difference between us is your expectation of being able to colonise a world and self sustain a colony or base with only a couple hundred people. Currently a self sustained society needs millions of people to keep going and cities full of hardware. I might be willing to accept that we might be able to do it with tens or hundreds of thousands of people in 50 years; but not hundreds, and certainly not with what a ship could carry. So given my expectation that planets with a bio-sphere would be unsurvivable for any period of time, and the crews will be strongly limited by the spare parts the ship can carry. The mision couldn't sustain the open ended operations you seem to be assuming. So going there doesn't give the crew the option of living on their own, or starting a sustainable society. This probably accounts for our different reaction toward one-way missions. Kelly From popserver Mon Jan 15 03:24:20 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["338" "Sun" "14" "January" "1996" "22:07:38" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "10" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA21390 for ; Sun, 14 Jan 1996 19:11:10 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id WAA20818; Sun, 14 Jan 1996 22:07:38 -0500 Message-ID: <960114220720_116629868@mail06.mail.aol.com> From: KellySt@aol.com To: David@interworld.com, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 22:07:38 -0500 >> ---- Anyway, remember: this is a thought experiment. Why >> we are going is not as important as HOW we are going - is >> it possible, and if so, how could it be done? Well thats a good point. Of course the why effects the how. But since we don't seem to be geting very far in the how departments its probably a mute point. Kelly From popserver Mon Jan 15 05:05:53 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["13626" "Sun" "14" "January" "1996" "23:57:34" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "307" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA26569 for ; Sun, 14 Jan 1996 20:58:30 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id XAA17237; Sun, 14 Jan 1996 23:57:34 -0500 Message-ID: <960114235734_42026576@emout05.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com Subject: Re: Engineering Newsletter Date: Sun, 14 Jan 1996 23:57:34 -0500 Kely Re:Timothy replies to Kelly: > > >Oh, I still say there is no significant difference between a suicide flight, > >and a flight where the crew are abandoned with enough supplies to last them > >their life. I am frankly shocked that you and Tim could seriously suggest > >such a horrific and ruthless option. Thats like sending a team to antartica, > >on a one way trip to the pole with no resuply and recovery runs! "Hey guys, > >go there, explore, radio back what you find, and here's 50 years supplies and > >parts for you to live out you life with." > > Summarizing what I write in this letter: > - We have to discuss what is necessary for a small colony. If it is to be self sufficent. It would need the resources of a small country now. (Thou no current country is self suficent, the current estimate is about 7 million people to maintain current society.) > - You can't compare Antarctica with a new planet full of life. True, Antartica would be far more habtable and survivable, but its the best quick example I could come up with. Then again, since antartic is so much easyier to settle, and we don't. Why would we settle in another star system. > - We (or I) don't see it as dropping people without any regard, but as a well > organized lifetime adventure. When the gear runs out. It will be far less adventurous, and much more tedious. > - Do things break down or get lost faster than one can repair or replace them? In aircraft, one lists how many man-hours of work per hour of flight. For exploration gear it could get that bad. I'ld expect the hab deck could keep going for a couple decades with minimal repairs. Probably the same for the heavy power and water systems. The mini ships and shuttles, or ground rovers would probably be geting tired after a few years of hard use. > How had you planned to connect the torus-shaped hab-rail to the ship? The > loads of a 100 metre arm should be multiplied by 100! See my Web page. In general the hab-deck track is attached to the outer hull. > >You keep missing the point that the ship doesn't need to be generating the > >power to accellerate the fuel. Tus it would need as much fuel for power. > > The over all energy expenditure of the systems is irrelavant. > > It is indeed clear to me that the ship does need less power, because it > doesn't need to accelerate its own fuel. But if the over all expenditure of > the system is irrelevant, why is it such a problem to accelerate a 1:1000000 > ship:fuel combination? Such a ship would accelerate, it just needs a lot of > engines (or one very powerful one). That asumes the engines can provide the thrust equivelent to 1,000,000 times their own weight. No engines now made can do that. The best fusion engines I've heard specilated about can do 6 times there weight. We could probably expect that to go up to 20, but not a million. > By the way I still don't see how you possibly can say that the amount of > energy needed doesn't matter. (Yes, I know as long as we have no working > method...) If it doesn't need to be carried by the ship, it doesn't effect the ability of the ship to function. That gear can stay at home and be serviced by facilities and people thatthe ship doesn't need to carry. ============================================================================ > >Would you say the same about missions to the Earths poles? Fairly common and > >trivially cheap compared to this. A far, far more habitable environment than > >any alien planet is likly to offer. Yet no one has attempted to colonize > >Antartica. What would be the point? > > On the poles you won't find a whole new planet full of life. If we indeed > knew there were only a few boring planets with nothing more than dust, we > would probably go somewhere else or not go at all. Doesn't matter for survival. Planets with Bio-spheres would be uninhabitable. Actualy its unlikely any planet would be habitable to us. > ------ Now I'm > interested to know what would be the minimal amount of machines to start at > a reasonable level. (say the level of our current technology, meaning > pentium-computers, Scanning microscopes etc.) > I've not a good idea of what to take, do you? (Has this subject been > discussed before?) Several times. > - Life sustaining habitats. > - Nano tech would be a great help for ore extracters > - Machines to make simple metal, plastic forms. > > A lot of these machines we probably need on the Asimov during its 25 year > mission, most computer won't last for 25 years continuous work. Taking with > us a lot of reserve chips seems a bit too simplistic to me. > (Even the food growing-machines are nessecary, eating 10 year old food all > the time is yuck) The heavy equip probably can give a 40 year service life. Computers can do a couple decades if well made, and are light enough so several sets of spares can be carried. To keep down the weight I was figuring no food rasiing on the ship. Instead 20 years of standard frozen foods in cryo, and 20 years of concentrated rations. The rations are only for use for the ship to hold on for rescue if they can't make it back. (I was assuming a standard mission of 20 years round trip. Thou we may need to streach it a bit more.) > >Again you seem to be assuming they have tremendous resources of equipment and > >time. They would be extreamly limited, and given the dangerous nature of > >their mission. They are probably going to be losing stuff (people and > >equipment) fairly quickly. Without Earth benificent supply runs. They are > >going to be in bad shape fairly soon. > > How fast are they loosing too much supply in a two-way mission? Even such a > mission should stay there for about 10 years researching planets. > They will be loosing stuff but if it goes in the rate you are predicting, > then every mission is suicide. Again I was expecting shorter missions, with a 2 maybe 3 year layover in system. > >> The people going there aren't the people who really want to retire, these > >> are people that are born for exploration and research. (They really exist) > >> My guess is that they wouldn't sit all the time in some ship or > >> compartment, > >> but that they would allow themselves to go to the planets surface (in > >> spacesuits). > > > >Most of them will never be able to go to the planets. After a while none of > >them will be able to as the equipment runs out. If they have to plan on a > >long stay, they'll have to curtail exploration fairly quickly in order to > >save the equip for more practical uses. > > That may indeed be the case, but a 10 year exploration with 100 people is > hardly enough to do any real research of a complete solarsystem. Not to > mention refueling or building complete beaming-arrays (only advanced > nano-tech or anti-matter might overcome that problem). Which was one of the reasons why I was arguing against such things. > >No its more fundamental than that. Theirs just too many people. The more > >people the more corrdination efforts. For example I worked in the Space > >Station Freedom headquarters along with a few thousand other people. NONE of > >us actually worked on the space station. We worked to coordinate information > >between all the groups. The more people, the harder it is to keep everyone > >informed. On a big goverment project, everyone has to know what everyone > >else is doing. The more agencies, the more paths of interaction. Since > >governments tend to demand everything is monitored to the finest detail. The > >vast bulk (maybe 80%-90%) of the group effort is in meeting and reports to > >keep everyone else informed. > > What if everyone informed themselves? It's like the internet, people make > information available, othera read it and if they don't agree, they discuss > it with the author, after discussing they come to a common conclusion (if > not, that's because of stubbornness) which is made public again. > Also not all people need to know about everything in such a big project, > there are many specialized groups, but they should not loose the survey of > the project. Doesn't really help. Instead of everyone getting to gether in a meeting where everyone presents their material and discuses it. You have people doing the same thing one at a time over the net. > >> Maybe even one country is too big? > > > >Certainly one buracracy is! > > Then there may be a big problem, because such a big project would need a lot > of people. If the project is organized by a small central group running autonomous projects. Its possible. Add in multiple governments and you have a big problem. > >Why not radically differnt? Life on earth is all based on a couple of basic > >chemical and anitomical tricks. There isn't anything special about those > >tricks. MANY others would work as well. I imagine most life out their will > >be radically different from that here, and may have a few times as long as > >Earth had to develop. > > The main tricks are based on storing and retreiving energy in and from > molecules, that energy comes from the sun or from planet-heat (vulcanos). > Are there many easy reactions that can do that back and forth. (a cycle > reaction is probably to unlikely)----- Lifes a lot more complicated then that. But if it all has the same chemistry it can counter attack. But the subtel chemistry and biostructures that immune defenses use could be completely wrong to deal with the threat. > >I suggested that a few months ago and got no interest. I suppose it moves > >this project from a serious attempt to figure out if we could do it in 2050. > > To a science fiction club. > > Then we should end the discussion about engines with the conclusion that > only exotic fuels and/or enormous powerstations could make the trip > possible. The techniques needed are only in a early theoretical stage and > the size of what is necessary is (almost) beyond imagination and reasonabless. Then what else is there left to talk about? > >> You can never tell :) people are worring about many things (like asteroids > >> colliding with Earth or the Asimov :)) > >> If humanity ever becomes extinct, it will be likely that it is not because > >> of natural disasters. > > > >Well nature is our worst enemy, but then we are very hard to kill. > > Even on a planet 10 ly away? I'm assuming we're not stupid enough to go on the planets. > > >More to the point we could built fleets of O'Niel sized space colonies here > >for far less than this project. And they wouldn't have the resorce, access, > >and communication limits of a star colony. > > You say these colonies are dependant on Earth, what if such a disaster > happens, then they won't have much resources any more. The colonies in Sol space can develop rapidly and become very large. Because they could pay for their own way they could afford that, and pay for all the supplies and equipment they'ld need. Should Earth be trashed somehow. They would at least have all their resources and the resources of the other colonies to draw on. What they need they could trade the recovering Earth civilization for. (Or salvage from the remains.) Unlike a couple hundred people in another star system. Who just have to hope the folks back home stay rich enough to pay for the supply flights. > >I would say just the oposite. Life on a T.C. colony will be hard and very > >limited. The planets would be ignored, and the platform colony would need a > >lot of work to equip and maintain. They would be far more dependant and > >under the control of whoever runs the supply flights, then a similar colony > >in Sol space. > > At sol there can't be planet based colonies because of the wrong gravity. > (only Venus has a comparable g but it's a bit hot out there) > You keep saying that it takes a lot of effort to keep the colony working, I > wonder if that is true: Do you need to repair a lot in your house? (not a > personal question) OK, a house on a barren planet would be different, but I > cannot believe that everyone is constantly busy repairing things. Again you can't use the planets. Of course people are constantly busy repairing or replacing everything! What do you think most of the efforts of civilization go toward here? We're constantly working to maintain and replace everything from homes and cars, to worn out cloths and paper clips. Except here we have a trmendous industrial advantage due to the scale of those operations. On a colony world it would be harder, and take longer. We'ld be forced to try to keep old equipment runing that really should be replaced. > >If you didn't already have the credientials,you wouldn't be offered a ride. > > (You would be stunned at the credentials NASA can require for astrounauts > >that only get to fly every yeear or three. On the other hand the turn over > >rate among the astronuate is pretty high. They are highly competative > >people. After they do this, they want new chalenges and get bored. > > Probably the normal astronauts are suited for such a trip. If they indeed > want new challanges every few years, they are probably on the wrong trip. > This trip is a carreer for life, even if you make it a two-way trip. > Who would volenteer for a trip that could take deacdes but only give them a couple years work in the star system? Or even worse if after that you are abandoned in the starsystems with nothing to do but last out as long as the ship holds out? Or worse yet, expected to slave away maintaing the thing, like being traped in a decades long Apollo 13 mission. Kelly From popserver Mon Jan 15 18:00:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1571" "Mon" "15" "January" "1996" "13:51:04" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "34" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id EAA12394 for ; Mon, 15 Jan 1996 04:48:16 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id NAA16954; Mon, 15 Jan 1996 13:49:38 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA17876; Mon, 15 Jan 96 13:51:04 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601151251.AA17876@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, KellySt@aol.com Cc: zkulpa@sunet.se Subject: Re: Engineering Newsletter Date: Mon, 15 Jan 96 13:51:04 +0100 > From KellySt@aol.com Fri Jan 12 03:34:37 1996 > > Oh, I still say there is no significant difference between a suicide flight, > and a flight where the crew are abandoned with enough supplies to last them > their life. I am frankly shocked that you and Tim could seriously suggest > such a horrific and ruthless option. Thats like sending a team to antartica, > on a one way trip to the pole with no resuply and recovery runs! "Hey guys, > go there, explore, radio back what you find, and here's 50 years supplies and > parts for you to live out you life with." > Horrific and ruthless? If you send them for such a trip against their will - then you are possibly right. But if they are willing? There is a good ol' rule of Roman law: "Who is willing, does not suffer" [sorry if I do not used the correct English version of the text]. Besides, everybody must die some time - what is that real & shocking difference between dying in Antarctica and in Sometown, Montana? With the starflight, another important factor is added: the return flight is long (of the order of at least 10 years, say), thus those returning will have only few years to enjoy their medals on Earth, not to say of the boring years on the ship with nothing exciting to do (except betting if the next ship gear failure will be fatal...) and rather risky - the probability of irreparable failure of the ship during the flight is much larger than the failure of the outpost base. I, frankly, would prefer to stay at the outpost. It might significantly increase my life expectance... -- Zenon From popserver Mon Jan 15 18:01:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1359" "Mon" "15" "January" "1996" "14:02:24" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "29" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id EAA12670 for ; Mon, 15 Jan 1996 04:59:42 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id OAA18694; Mon, 15 Jan 1996 14:00:58 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA17950; Mon, 15 Jan 96 14:02:24 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601151302.AA17950@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, KellySt@aol.com Cc: zkulpa@sunet.se Subject: Re: Engineering Newsletter Date: Mon, 15 Jan 96 14:02:24 +0100 > From KellySt@aol.com Fri Jan 12 03:34:37 1996 > > [...] > No its more fundamental than that. Theirs just too many people. The more > people the more corrdination efforts. For example I worked in the Space > Station Freedom headquarters along with a few thousand other people. NONE of > us actually worked on the space station. We worked to coordinate information > between all the groups. The more people, the harder it is to keep everyone > informed. On a big goverment project, everyone has to know what everyone > else is doing. The more agencies, the more paths of interaction. Since > governments tend to demand everything is monitored to the finest detail. The > vast bulk (maybe 80%-90%) of the group effort is in meeting and reports to > keep everyone else informed. > The key phrase is: "Since governments tend to demand everything [, everything] is monitored to the finest detail", not the "just too many people". 80%-90% of this "coordination" is not necessary. Did all people involved really READ (with attention) ALL that "coordination" stuff? Put the task as a question of survival (of the humanity, of the company, of the people involved...) instead of as a government project that must be reported back in all, important or not, details - and the effectiveness rises several times (if not orders of magnitude...). -- Zenon From popserver Tue Jan 16 18:04:57 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8996" "Tue" "16" "January" "1996" "17:59:09" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "179" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA19862 for ; Tue, 16 Jan 1996 08:58:25 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11176 (5.67b/IDA-1.5 for ); Tue, 16 Jan 1996 17:59:03 +0100 Message-Id: <199601161659.AA11176@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Tue, 16 Jan 1996 17:59:09 +0100 Timothy replies to Kelly: >I think the central difference between us is your expectation of being able >to colonise a world and self sustain a colony or base with only a couple >hundred people. Indeed, that seems to be the difference between us, Zenon has a bit other attitude, saying that people should decide for themselves what they want (to which I do not agree completely but also do not disagree completely, it's like smoking, it's bad but not bad enough (No... I don't smoke)). Where Zenon and I do agree is that staying at TC may be less dangerous than flying all the way back home. >Currently a self sustained society needs millions of people to keep going and >cities full of hardware. I might be willing to accept that we might be able >to do it with tens or hundreds of thousands of people in 50 years; but not >hundreds, and certainly not with what a ship could carry. I've doubts about that, a lot of things are unnessary renewed also a lot of effort is used to develop new things, if we would maintain the current level of technology and not innovate, we probably had a lot more spare time. ============================================================================ >> - You can't compare Antarctica with a new planet full of life. > >True, Antartica would be far more habtable and survivable, but its the best >quick example I could come up with. Then again, since antartic is so much >easyier to settle, and we don't. Why would we settle in another star system. What I meant is that a new planet would give us more than Antarctica could, I don't mean that it could be a place to live, but a place to get much new scientific information. >That asumes the engines can provide the thrust equivelent to 1,000,000 times >their own weight. No engines now made can do that. The best fusion engines >I've heard specilated about can do 6 times there weight. We could probably >expect that to go up to 20, but not a million. OK, take 1 engine that could acclerate itself and 19 other engines, than the other 19 engines didn't need to accelerate themselves anymore so they could use all their power to accelerate the ship. >If it doesn't need to be carried by the ship, it doesn't effect the ability >of the ship to function. That gear can stay at home and be serviced by >facilities and people thatthe ship doesn't need to carry. Storing fuel doesn't need much that much facilities. >Doesn't matter for survival. Planets with Bio-spheres would be >uninhabitable. Actualy its unlikely any planet would be habitable to us. We would not live on those planets, we would do research in spacesuits or with remote controlled robots. Maybe after we had figured out an anti-dote against most diseases we might want to live there. I don't see why good planets without live could not be used. Slowly I'm thinking of not going to a planet to live there: The main advantage of a planet are its ore resources, (assuming you can't live there without spacesuits. So why would we want live on a planet at all, space-stations could live near asteroids for their ores, the could fly away whenever they had enough materials. This does not mean that going to a planet to research it isn't useful! >To keep down the weight I was figuring no food rasiing on the ship. Instead >20 years of standard frozen foods in cryo, and 20 years of concentrated >rations. The rations are only for use for the ship to hold on for rescue if >they can't make it back. (I was assuming a standard mission of 20 years >round trip. Thou we may need to streach it a bit more.) Aaagh 20 years of drinking porrige, OK I'm out, I won't go anymore. Although we could bake some bread or won't flour hold for that long? Nah, bread and porrige that still isn't eatable. >Again I was expecting shorter missions, with a 2 maybe 3 year layover in >system. That makes Kevin's array-building even more difficult. Also doing any real research would not be possible. Besides that 3 years research for 15 years of travel is not acceptable, it would really be a waste of man power. So I think your idea of the goal of the mission isn't right. >>>Most of them will never be able to go to the planets. After a while none of >>>them will be able to as the equipment runs out. If they have to plan on a >>>long stay, they'll have to curtail exploration fairly quickly in order to >>>save the equip for more practical uses. >> >> That may indeed be the case, but a 10 year exploration with 100 people is >> hardly enough to do any real research of a complete solarsystem. Not to >> mention refueling or building complete beaming-arrays (only advanced >> nano-tech or anti-matter might overcome that problem). > >Which was one of the reasons why I was arguing against such things. Huh, I can't follow you, am I right that you are against refueling or building beaming arrays? If so, than the trip may indeed become very difficult. >> The main tricks are based on storing and retreiving energy in and from >> molecules, that energy comes from the sun or from planet-heat (vulcanos). >> Are there many easy reactions that can do that back and forth. (a cycle >> reaction is probably to unlikely)----- > >Lifes a lot more complicated then that. Yes, but once you have the same base things are a lot less different. >But if it all has the same chemistry >it can counter attack. But the subtel chemistry and biostructures that >immune defenses use could be completely wrong to deal with the threat. Yes, we have also very powerful medcines, take penicillin, it has a very broad range, and can kill many diseases at once, probably a lot of extraterrestial ones too. >> Then we should end the discussion about engines with the conclusion that >> only exotic fuels and/or enormous powerstations could make the trip >> possible. The techniques needed are only in a early theoretical stage and >> the size of what is necessary is (almost) beyond imagination and >reasonabless. > >Then what else is there left to talk about? I don't know, maybe there are other interesting subjects where everyone like to discuss about. Or we should summarize and break up but that sounds so hard after 1.5 years of writing. >> Even on a planet 10 ly away? > >I'm assuming we're not stupid enough to go on the planets. Oh yes, I forgot that :)) >> At sol there can't be planet based colonies because of the wrong gravity. >> (only Venus has a comparable g but it's a bit hot out there) >> You keep saying that it takes a lot of effort to keep the colony working, I >> wonder if that is true: Do you need to repair a lot in your house? (not a >> personal question) OK, a house on a barren planet would be different, but I >> cannot believe that everyone is constantly busy repairing things. > >Again you can't use the planets. Why not even a lifeless ones assuming they have almost the right gravitation? >Of course people are constantly busy repairing or replacing everything! What >do you think most of the efforts of civilization go toward here? We're >constantly working to maintain and replace everything from homes and cars, to >worn out cloths and paper clips. Except here we have a trmendous industrial >advantage due to the scale of those operations. On a colony world it would >be harder, and take longer. We'ld be forced to try to keep old equipment >runing that really should be replaced. A lot of things in the current civilization are too easely discarded of, a lot of things are bought new because a single part needed to repair the thing is more expensive or not possible to buy. Besides that a lot of appliances aren't build to repair. I can give you dozens of examples where an easy single repair can save a whole apparatus but you have to do it yourself because others can't or won't repair it. Also a lot of the current resources are use for devellopment not for reproduction. On TC we don't need to worry how we can make faster computers or better lightbulbs for the first few decades. So this is why I think that a lot less people are needed than you suggest. The things that really need to be renewed are a lot less and so you need a lot less people. >> Probably the normal astronauts are suited for such a trip. If they indeed >> want new challanges every few years, they are probably on the wrong trip. >> This trip is a carreer for life, even if you make it a two-way trip. > >Who would volenteer for a trip that could take deacdes but only give them a >couple years work in the star system? Or even worse if after that you are >abandoned in the starsystems with nothing to do but last out as long as the >ship holds out? Or worse yet, expected to slave away maintaing the thing, >like being traped in a decades long Apollo 13 mission. So now we do not only have a no engine but we also don't have a crew who does want to fly the ship, if there was an engine. This discussion gets easier by the minute :) I guess that we also don't have anyone who wants to build it if it was possible. Timothy From popserver Tue Jan 16 18:05:02 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5849" "Tue" "16" "January" "1996" "17:58:53" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "132" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA19848 for ; Tue, 16 Jan 1996 08:58:04 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11154 (5.67b/IDA-1.5 for ); Tue, 16 Jan 1996 17:58:46 +0100 Message-Id: <199601161658.AA11154@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Tue, 16 Jan 1996 17:58:53 +0100 Timothy replies to Kevin: >Oh, you two can go on argueing if you want to, don't let me stop you. I >just thought that the ground had been covered many times before in finest >detail. I did not realize that you were still confused as to what Kelly >meant. i suppose that's my own fault for thinking that all members of >this group speak english with perfect understanding (typical american >attitude i know, but at least I can admit my mistake) I'm just glad this >dicussion isn't taking place in Dutch or Polish I understand what Kelly means, but not why he thinks it. I'm also glad the discussion is not in Polish :) For me it doesn't matter much if I have to write English or Dutch, most words I know, the ones I don't I can quickly look up in my computerized dictionary which I use about 4 times per letter. Reading the kind of English that you guys write is not too difficult so I can almost always manage without any help. >and a lot smaller if you could put in orbit at mercury's distance. Yes a radius of 580 kilometre, but would it not become too hot? (the radiation level is about 10000 Watt/m^2) >> That would always be anti-matter or a beam that is very tight. > >i don't agree, that's true only if you want to do it in a man's >lifetime. if you are willing to accept a lower speed, then you can do >the trip with a _lot_ less energy. The the answer is also easy, with one Joule you could come everywhere. (live support not included ;) ) >I meant by eff. Question, "what will the eff. of energy to antimatter >conversion be?" or How many kilowatts does it take to make a gram of >anti-matter? Theoretically I'd say m=0.5 E/c^2 because if you create anti-matter, you create have to create an equal amount of matter. So that means a maximum efficiency of 50%. When creating the anti-matter the amount of lost energy could be kept small (10%) by reusing the wrong anti-matter and by "recycling" the lost heat. So anti-matter efficiency in total may indeed not so big as hoped. Maybe 30% after having used it in the spacevessel. >> You could see anti-matter just as ordinary matter. All physic laws that are >> valid for matter do hold for anti-matter. Thus fusion would work. >> In fact Hydrogen is also a metal, it just has a very low melting point, I > >only if you put it under a hellish pressure. No, the tables I use say that it gets solid at 14K for normal pressure (1 Atm.) >Actually, if we could get any respectable solid at all, like Li maybe, >then we could give it an electricall charge and keep it suspended that way Yes, I proposed that idea some weeks ago. >> How much work can one robot unit do? Say 1m^2/second. >> So that means about 3E4 robots are needed. >> How long would one robot need to replicate itself? Say 3 days. >> Using exponetial growth: 2^T=3E4 --> T=173 --> 3*T=519 days needed to make >> 3E4 robots. > >Tim, i think you have a little problem here. 2^173= 1.19 E+52 robots Yes, I did 173^2=3E4, really stupid... >In fact, I'm having trouble following where some of your numbers come from. >assuming that your 1000 Km radius solar array is correct, I get > >(1000 * 1000)^2 *PI() = 3.14 E+12 m^2 of solar cells I rounded it to 1E12... >i think your estimate of solar cell production is way too liberal, >I say 1 m^2/day is more likely. > >so now we need 8.6 E08 robots to do the job in ten years > >I think your three day replication estimate is good. > >using exponential growth, I get 2^T=8.6 E08 T=29 days 3 * T =89 days > >thats if we start with one robot. I think we would probably start with a >1000. That would save 30 days, is it worth carrying that much extra load to gain 30 days? > if we let reproduction continue for 100 days ( nice round number) >we'd have 8.59 E09 robots 1E13 Robots, or did you start with one instead of 1000 robots? (Note: Probably all robots will be worn out after a few years, so you may need 3 or 4 times more than you originally would think, that would only cost a few days extra) >, and at the lesuirely rate of 1 m^2/day, we >could build the entire solar array in 365 days. 100 robots could work on >each maser transmitter, and all of them could be built in a month. we'd >still have plenty of robots left over to build habitats, mine fusion >fuel, or whatever other job we needed done. with that many pentium level >processers, the resultant computer power would be staggering! Yeah, not to mention the memory they would have 10 PentaBytes (1E16 bytes), but only if they can communicate well enough... >Now, as Kelly says, when you get this many "Grunts", the job of the top >boss becomes more and more difficult. but with several layers of "middle >managment" computers, I think it would be doable ( although, maybe not at >the speed I was reffering to For 3E4 robots I thought it could be controlled, but 1E10 may become a serious problem. If they use radio communication to check each other, they need a quite broad bandwith. Also the chance for collisions may increase significantly. Another problem by building the array may be the amount of materials that have to be transported. Say a solar cell weighs 2 kg/m^2, so the total weight of the array is about 2 * 3.14E12 kg. That makes about 1.7E9 kg per day, that's not nothing... >yeah, I think we are going to need that technology in many areas. >Computer circuitry, accelerator coils, fusion containment coils anywhere >you have a lot of energy, and no way to remove the heat. Computer circuits mostly need semi-conductors, so I think super-conductors may not work there. But the other applications may be useful. Oh by the way, super conductors can't conduct infinite currents... I don't know what their maximum is though, I asked someone who worked with them but he didn't know either, they used only small currents and small pieces. Timothy From popserver Wed Jan 17 04:59:44 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1968" "Tue" "16" "January" "1996" "23:21:44" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "44" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA20729 for ; Tue, 16 Jan 1996 20:21:52 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id XAA18592; Tue, 16 Jan 1996 23:21:44 -0500 Message-ID: <960116232037_44190111@emout05.mail.aol.com> From: KellySt@aol.com To: zkulpa@lksu.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com cc: zkulpa@emin09.mail.aol.com Subject: Re: Engineering Newsletter Date: Tue, 16 Jan 1996 23:21:44 -0500 > [...] > > No its more fundamental than that. Theirs just too many people. The more > > people the more corrdination efforts. For example I worked in the Space > > Station Freedom headquarters along with a few thousand other people. NONE of > > us actually worked on the space station. We worked to coordinate information > > between all the groups. The more people, the harder it is to keep everyone > > informed. On a big goverment project, everyone has to know what everyone > > else is doing. The more agencies, the more paths of interaction. Since > > governments tend to demand everything is monitored to the finest detail. The > > vast bulk (maybe 80%-90%) of the group effort is in meeting and reports to > > keep everyone else informed. > > > The key phrase is: > "Since governments tend to demand everything > [, everything] is monitored to the finest detail", > not the > "just too many people". > 80%-90% of this "coordination" is not necessary. > Did all people involved really READ (with attention) > ALL that "coordination" stuff? > Put the task as a question of survival > (of the humanity, of the company, of the people involved...) > instead of as a government project that must be reported back > in all, important or not, details - and the effectiveness > rises several times (if not orders of magnitude...). In an international program there is also the bit that everyone wants a peice of the project. With it broken down into so many paices, no one can keep track of whats going on. Hence the coordination effort. Some organizations do keep that up even at the price of there survival. Especially government programs. To cut out the wasted overhead would require massive layoffs and political repercusions. Obviously if the organization is doing something critical its usually kept minimally gummed up. But given that this project can't in anyway be considered critical, it would be unlikely to get clear of that. Kelly From popserver Wed Jan 17 04:59:50 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1750" "Tue" "16" "January" "1996" "23:24:21" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "36" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA21078 for ; Tue, 16 Jan 1996 20:27:16 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id XAA19423; Tue, 16 Jan 1996 23:24:21 -0500 Message-ID: <960116232024_44189821@mail02.mail.aol.com> From: KellySt@aol.com To: zkulpa@lksu.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com cc: zkulpa@emin06.mail.aol.com Subject: Re: Engineering Newsletter Date: Tue, 16 Jan 1996 23:24:21 -0500 > Horrific and ruthless? > If you send them for such a trip against their will - > then you are possibly right. > But if they are willing? > There is a good ol' rule of Roman law: --- So, If you find someone willing to blow their brains out on camera, if the footage will be shone on the evening news. You don't think the news photagapher who says "sure, go for it" has any moral responsibility? > Besides, everybody must die some time - > what is that real & shocking difference between dying > in Antarctica and in Sometown, Montana? > With the starflight, another important factor is added: > the return flight is long (of the order of at least 10 years, say), > thus those returning will have only few years to enjoy > their medals on Earth, not to say of the boring years > on the ship with nothing exciting to do (except betting > if the next ship gear failure will be fatal...) > and rather risky - the probability > of irreparable failure of the ship during the flight > is much larger than the failure of the outpost base. > I, frankly, would prefer to stay at the outpost. > It might significantly increase my life expectance... You have a choice of 10 years in the ship betting on its systems not failing on its return flight. Vs the rest of your life in that same ship parked in the system, or a base built out of the ships parts, still better the systems don't fail. Unless your assuming you'll die in less than 10 years of natural causes. I can't see how you could take the return flight as safer. In any event its accademic. No political organization would be allowed to support or allow such a flight. Since such a flight can't be done without them in the next 50 years. The option, ruthless as it is, is closed. Kelly From popserver Wed Jan 17 04:59:52 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9846" "Tue" "16" "January" "1996" "23:29:35" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "226" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA21301 for ; Tue, 16 Jan 1996 20:30:43 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id XAA24371; Tue, 16 Jan 1996 23:29:35 -0500 Message-ID: <960116232114_44190980@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com Subject: Re: Engineering Newsletter Date: Tue, 16 Jan 1996 23:29:35 -0500 Kelly replies to Timothy: > > >I think the central difference between us is your expectation of being able > >to colonise a world and self sustain a colony or base with only a couple > >hundred people. > > Indeed, that seems to be the difference between us, Zenon has a bit other > attitude, saying that people should decide for themselves what they want (to > which I do not agree completely but also do not disagree completely, it's > like smoking, it's bad but not bad enough (No... I don't smoke)). Where > Zenon and I do agree is that staying at TC may be less dangerous than flying > all the way back home. I can't see how staying would be safer. Unless you expect the drive system to fail? Your still relying on the the same life support systems. > >Currently a self sustained society needs millions of people to keep going and > >cities full of hardware. I might be willing to accept that we might be able > >to do it with tens or hundreds of thousands of people in 50 years; but not > >hundreds, and certainly not with what a ship could carry. > > I've doubts about that, a lot of things are unnessary renewed also a lot of > effort is used to develop new things, if we would maintain the current level > of technology and not innovate, we probably had a lot more spare time. Actually most companies only spend about %5 on research and development. The rest goes to manufacturing. So I don't expect a big saving there. Later in this letter you mentioned this idea again and suggested if systems were designed to be maintained they would require less replacement. To a degree true. But after a couple decades everthing wears out; and the reason we got used to throwing away things rather than repairing them, is its cheaper and takes less effort. ============================================================================ > > >> - You can't compare Antarctica with a new planet full of life. > > > >True, Antartica would be far more habtable and survivable, but its the best > >quick example I could come up with. Then again, since antartic is so much > >easyier to settle, and we don't. Why would we settle in another star system. > > What I meant is that a new planet would give us more than Antarctica could, > I don't mean that it could be a place to live, but a place to get much new > scientific information. Agreed. For scientific purpose a alien biosphere would be a goldmine! But it wouldn't help the crew to survive. > >That asumes the engines can provide the thrust equivelent to 1,000,000 times > >their own weight. No engines now made can do that. The best fusion engines > >I've heard specilated about can do 6 times there weight. We could probably > >expect that to go up to 20, but not a million. > > OK, take 1 engine that could acclerate itself and 19 other engines, than the > other 19 engines didn't need to accelerate themselves anymore so they could > use all their power to accelerate the ship. That works for 20 to one. But you still have the weight of the fuel for the one. > >If it doesn't need to be carried by the ship, it doesn't effect the ability > >of the ship to function. That gear can stay at home and be serviced by > >facilities and people thatthe ship doesn't need to carry. > > Storing fuel doesn't need much that much facilities. But it does take a lot of facilities to carry and move it. > I don't see why good > planets without live could not be used. Probably any planet about earth size would have life (assuming its not radically hot or cold. > Slowly I'm thinking of not going to a planet to live there: The main > advantage of a planet are its ore resources, (assuming you can't live there > without spacesuits. So why would we want live on a planet at all, > space-stations could live near asteroids for their ores, the could fly away > whenever they had enough materials. Right, thats why I keep talking about space colonies. Raw materials are far easier to get at in space then on a planet. By mid 21st century we'll probably be moving a lot of our heavy industry of earth and into space for that reason (expect the third world to screem!), so I expect our starship crew would not think of trying to get ore up off a planet. > >To keep down the weight I was figuring no food rasiing on the ship. Instead > >20 years of standard frozen foods in cryo, and 20 years of concentrated > >rations. The rations are only for use for the ship to hold on for rescue if > >they can't make it back. (I was assuming a standard mission of 20 years > >round trip. Thou we may need to streach it a bit more.) > > Aaagh 20 years of drinking porrige, OK I'm out, I won't go anymore. > Although we could bake some bread or won't flour hold for that long? > Nah, bread and porrige that still isn't eatable. ???! Not me dude. People who lock large groups of people in steel hull and feed them badly get hunted down and beaten up! ;) I was expecting to store standard groceries. Meat, eggs, milk, vegies, breads, pasta all that stuff. With the exception of the emergency rations, which would be optimized for high nutritian and low weight. Everything would be as standard as possible. Thats why I used food weight numbers for home consumers, not exploration or military missions. > >Again I was expecting shorter missions, with a 2 maybe 3 year layover in > >system. > > That makes Kevin's array-building even more difficult. Also doing any real > research would not be possible. Besides that 3 years research for 15 years > of travel is not acceptable, it would really be a waste of man power. So I > think your idea of the goal of the mission isn't right. Well you have to call and end to it sometime. I figured a couple years in systems would be all we could manage. Maybe a bit more than 3 years, but certainly not anywhere near 10. We need to keep the crews round trip time down below 30 years subjective (and not much more than that real time). I was also expecting a maximum ship service life of about 40 years. > >>>Most of them will never be able to go to the planets. After a while none of > >>>them will be able to as the equipment runs out. If they have to plan on a > >>>long stay, they'll have to curtail exploration fairly quickly in order to > >>>save the equip for more practical uses. > >> > >> That may indeed be the case, but a 10 year exploration with 100 people is > >> hardly enough to do any real research of a complete solarsystem. Not to > >> mention refueling or building complete beaming-arrays (only advanced > >> nano-tech or anti-matter might overcome that problem). > > > >Which was one of the reasons why I was arguing against such things. > > Huh, I can't follow you, am I right that you are against refueling or > building beaming arrays? If so, than the trip may indeed become very difficult. Beaming arrays yes. I was hoping we could get by on minning fuel for the fusion systems and maybe launching it. I was also assuming a larger number of people then you are. Maybe only a 100 people on the ground, but I expect total research team would be a thousand or more. (Note the size of my ship.) > >But if it all has the same chemistry > >it can counter attack. But the subtel chemistry and biostructures that > >immune defenses use could be completely wrong to deal with the threat. > > Yes, we have also very powerful medcines, take penicillin, it has a very > broad range, and can kill many diseases at once, probably a lot of > extraterrestial ones too. The only reason we can use anti-biotics at all is they trip up something suttle in the bacteria they attack. Even a slight variation of that bacteria species is uneffected. If the stuff effected something biologically fundamental. It would kil the patent as well as the desease. > >> Then we should end the discussion about engines with the conclusion that > >> only exotic fuels and/or enormous powerstations could make the trip > >> possible. The techniques needed are only in a early theoretical stage and > >> the size of what is necessary is (almost) beyond imagination and > >reasonabless. > > > >Then what else is there left to talk about? > > I don't know, maybe there are other interesting subjects where everyone like > to discuss about. Or we should summarize and break up but that sounds so > hard after 1.5 years of writing. Yeah, I'm begining to think we're doing this more out of habit then anything. Maybe thats why Dave can never seem to get around to fixing things on LIT. (I just got an E-mail from a new guy who wanted to join the newsletter and saw my name in the on-line archive and asked what the status is.) Maybe we should work up a conclusion reprt or something. > >> Probably the normal astronauts are suited for such a trip. If they indeed > >> want new challanges every few years, they are probably on the wrong trip. > >> This trip is a carreer for life, even if you make it a two-way trip. > > > >Who would volenteer for a trip that could take deacdes but only give them a > >couple years work in the star system? Or even worse if after that you are > >abandoned in the starsystems with nothing to do but last out as long as the > >ship holds out? Or worse yet, expected to slave away maintaing the thing, > >like being traped in a decades long Apollo 13 mission. > > So now we do not only have a no engine but we also don't have a crew who > does want to fly the ship, if there was an engine. This discussion gets > easier by the minute :) I guess that we also don't have anyone who wants to > build it if it was possible. Well we never could come up with a solid reason why people wanted to go there. It was just an assumption for the discussion that people would. So yes, maybe even if people could g, they wouldn't bother. We don't bother to send people to the moon or Mars? ;) Kelly From popserver Wed Jan 17 18:00:53 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["764" "Wed" "17" "January" "1996" "08:24:34" "-0500" "Kelly Starks" "kgstar@most.magec.com" "" "35" "Re: Fwd: Re: Engineering Newsletter" "^From:" nil nil "1" nil "Fwd: Re: Engineering Newsletter" nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA13045 for ; Wed, 17 Jan 1996 05:25:54 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA04049; Wed, 17 Jan 96 08:26:55 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI003985; Wed Jan 17 08:25:16 1996 Received: by most (4.1/SMI-4.1) id AA02434; Wed, 17 Jan 96 08:25:14 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002413; Wed Jan 17 08:24:36 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA09066; Wed, 17 Jan 96 08:24:33 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, zkulpa@lksu.ippt.gov.pl, hous0042@maroon.tc.umn.edu, stevev@efn.org, rddesign@wolfenet.com, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Fwd: Re: Engineering Newsletter Date: Wed, 17 Jan 1996 08:24:34 -0500 Oh, I was just talking about my old Explorer class starship stuff on LIT. The url is: http://sunsite.unc.edu/lunar/explorer.html At 11:23 PM 1/16/96, KellySt@aol.com wrote: >--------------------- >Forwarded message: >From: hous0042@maroon.tc.umn.edu (Kevin C Houston) >To: KellySt@aol.com >Date: 96-01-15 08:13:38 EST > >Kelly, > >You talk about having a web page, I missed the URL could you please send >it to me. > >Thanks >Kevin ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Wed Jan 17 19:48:52 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["843" "Wed" "17" "January" "1996" "20:46:24" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "21" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA09293 for ; Wed, 17 Jan 1996 11:43:32 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id UAA05251; Wed, 17 Jan 1996 20:44:56 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA26089; Wed, 17 Jan 96 20:46:24 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601171946.AA26089@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, KellySt@aol.com Cc: zkulpa@sunet.se Subject: Re: Engineering Newsletter Date: Wed, 17 Jan 96 20:46:24 +0100 > From KellySt@aol.com Wed Jan 17 05:25:15 1996 > > Obviously if the > organization is doing something critical its usually kept minimally gummed > up. But given that this project can't in anyway be considered critical, it > would be unlikely to get clear of that. > So - let us make it critical! Say, poke the Sol a little to show symptoms of becoming a nova... ;-)) Seriously, I am afraid it will become critical after some time - but then, who will spot it and have enough guts (see our discussion on one-way missions...) to draw the proper conclusions (and start the actions)... :-( -- Zenon P.S. Do not Cc: your messages to some zkulpa@emin09.mail.aol.com - that's not me (at least, I do not know about it), but apparently some other guy (if a guy it is... ;-)). Did you ever have got any answer from him? -- ZK From popserver Wed Jan 17 20:24:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3974" "Wed" "17" "January" "1996" "21:24:04" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "83" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA12651 for ; Wed, 17 Jan 1996 12:21:03 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id VAA10470; Wed, 17 Jan 1996 21:22:27 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA26178; Wed, 17 Jan 96 21:24:04 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601172024.AA26178@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, KellySt@aol.com Cc: zkulpa@sunet.se Subject: Re: Engineering Newsletter Date: Wed, 17 Jan 96 21:24:04 +0100 > From KellySt@aol.com Wed Jan 17 05:30:37 1996 > > > [Zenon:] > > Horrific and ruthless? > > If you send them for such a trip against their will - > > then you are possibly right. > > But if they are willing? > > There is a good ol' rule of Roman law: --- > > So, If you find someone willing to blow their brains out on camera, if the > footage will be shone on the evening news. You don't think the news > photagapher who says "sure, go for it" has any moral responsibility? > That is quite another story - publicizing somebody's desire to make a grisly spectacle for no purpose except shocking others... Anyway, if that someone wills to blow their brains - it is their, so let them do it - one fool less will be a service to humanity... Being the photographer, I would simply say that I'm not interested. You see, would anybody climb at the window ledge threatening to jump twenty stories down if nobody will come with cameras, psychiatrist, negotiator, fireman's brigade with long ladder and wailing siren? And 100% of such "desperados" somehow becomes easily persuaded not to jump (after he is sure all the media gave enough coverage of his attempt...). So do not mince matters, Kelly... > [Zenon:] > > Besides, everybody must die some time - > > what is that real & shocking difference between dying > > in Antarctica and in Sometown, Montana? > > With the starflight, another important factor is added: > > the return flight is long (of the order of at least 10 years, say), > > thus those returning will have only few years to enjoy > > their medals on Earth, not to say of the boring years > > on the ship with nothing exciting to do (except betting > > if the next ship gear failure will be fatal...) > > and rather risky - the probability > > of irreparable failure of the ship during the flight > > is much larger than the failure of the outpost base. > > I, frankly, would prefer to stay at the outpost. > > It might significantly increase my life expectance... > > You have a choice of 10 years in the ship betting on its systems not failing > on its return flight. Vs the rest of your life in that same ship parked in > the system, or a base built out of the ships parts, still better the systems > don't fail. Unless your assuming you'll die in less than 10 years of natural > causes. I can't see how you could take the return flight as safer. > Return flight is much less safe than living at the base, Kelly. That collossal engine, with all its terawats boiling inside - ready either to blow out or to stall, rather worn out after years and years of the first half of the flight. No resources to find in the void, nor means to stop and search... > In any event its accademic. No political organization would be allowed to > support or allow such a flight. Since such a flight can't be done without > them in the next 50 years. The option, ruthless as it is, is closed. > Political organizations (and opinions) are not laws of nature, but emanations of people's opinions and attitudes. If they (the people) have such attitudes as you seem to propagate in our discussion, that it's not surprising that they possibly will not "support or allow" ANY flight (that's risky, you know - untested technology, not complying to these mountains of government rules and regulations of safety, no guarantee of safe return, high probability of accidental loss of life, probably far larger than in Kuwait...). So, if we want to go to the stars at all, we must fight off such attitudes. Not to say of other resons to do so. I wonder - Lindbergh would be certainly not allowed to cross the Atlantic - in his personally constructed and build plane, without all those attestations and safety inspections, completely on his own, with no detailed progress reports to the government, etc., etc. - surely a suicide mission... If such attitude really prevails, farewell the future of humankind, either among the stars or right there on Earth... -- Zenon From popserver Thu Jan 18 03:06:08 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6868" "Wed" "17" "January" "1996" "18:01:28" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "164" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA09185 for ; Wed, 17 Jan 1996 16:00:19 -0800 (PST) Received: by maroon.tc.umn.edu; Wed, 17 Jan 96 18:01:29 -0600 In-Reply-To: <199601161658.AA11154@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Wed, 17 Jan 1996 18:01:28 -0600 (CST) Kevin replies to Timothy > Reading the kind of English that you guys write is not too difficult so I > can almost always manage without any help. I'm not sure if that is a compliment or a put-down ;) > > >and a lot smaller if you could put in orbit at mercury's distance. > > Yes a radius of 580 kilometre, but would it not become too hot? (the > radiation level is about 10000 Watt/m^2) I think the heat could be kept below the melting point of silicon. As the Temperature goes up, so does the blackbody radiation. > > >> That would always be anti-matter or a beam that is very tight. > > > >i don't agree, that's true only if you want to do it in a man's > >lifetime. if you are willing to accept a lower speed, then you can do > >the trip with a _lot_ less energy. > > The the answer is also easy, with one Joule you could come everywhere. (live > support not included ;) ) That reminds me of a great new travel method making use of Hiesenberg Uncertainty principle: as Temperature approaches Abs Zero, Momentum becomes zero to the last decimal, and the position becomes _infinite_. the recent cooling of some atoms down to nanokelvins of Abs Zero, makes me hopeful that this might someday work. although how you go from room temp to even a "balmy" -40 (celsius, Farenhiet, what's the diff. ;) ) is another question, but if you could make to that emp and survive, then perhaps you could make it to Abs Zero. > >> You could see anti-matter just as ordinary matter. All physic laws that are > >> valid for matter do hold for anti-matter. Thus fusion would work. > >> In fact Hydrogen is also a metal, it just has a very low melting point, I > > > >only if you put it under a hellish pressure. > > No, the tables I use say that it gets solid at 14K for normal pressure (1 Atm.) Solid yes. Metal, no. at one atm, hydrogen becomes an ice-like solid, which does not have any free electrons. only at great pressures (ie Jovian core) does the hydrogen take on any metallic properties. > > >Actually, if we could get any respectable solid at all, like Li maybe, > >then we could give it an electricall charge and keep it suspended that way > > Yes, I proposed that idea some weeks ago. > Oops, musta missed that one. > >assuming that your 1000 Km radius solar array is correct, I get > >(1000 * 1000)^2 *PI() = 3.14 E+12 m^2 of solar cells > > I rounded it to 1E12... > > >i think your estimate of solar cell production is way too liberal, > >I say 1 m^2/day is more likely. > >so now we need 8.6 E08 robots to do the job in ten years > >I think your three day replication estimate is good. > >using exponential growth, I get 2^T=8.6 E08 T=29 days 3 * T =89 days > >thats if we start with one robot. I think we would probably start with a > >1000. > > That would save 30 days, is it worth carrying that much extra load to gain > 30 days? one robot may not be able to replicate in three days, with out some minimum number of "support" units, to mine ore, cart raw materials to easy places etc etc > > > if we let reproduction continue for 100 days ( nice round number) > >we'd have 8.59 E09 robots > > 1E13 Robots, or did you start with one instead of 1000 robots? > Yes I did, sorry about that > (Note: Probably all robots will be worn out after a few years, so you may > need 3 or 4 times more than you originally would think, that would only cost > a few days extra) Any robot could probably repaired far cheaper than it could be re-built from scratch, and this could be done at any time, not just at the outset > > >, and at the lesuirely rate of 1 m^2/day, we > >could build the entire solar array in 365 days. 100 robots could work on > >each maser transmitter, and all of them could be built in a month. we'd > >still have plenty of robots left over to build habitats, mine fusion > >fuel, or whatever other job we needed done. with that many pentium level > >processers, the resultant computer power would be staggering! > > Yeah, not to mention the memory they would have 10 PentaBytes (1E16 bytes), > but only if they can communicate well enough... > i think TCP/IP would be much better suited to robotic units than to humans > >Now, as Kelly says, when you get this many "Grunts", the job of the top > >boss becomes more and more difficult. but with several layers of "middle > >managment" computers, I think it would be doable ( although, maybe not at > >the speed I was reffering to > > For 3E4 robots I thought it could be controlled, but 1E10 may become a > serious problem. If they use radio communication to check each other, they > need a quite broad bandwith. Also the chance for collisions may increase > significantly. This is where you have some robots dedicated to the task of routing. if each robot has a long-range low-bandwidth transmitter (to call for help, or report on distant conditions) and a high-bandwidth short-range (10m?) transmitter, then there should not be too much radio interferance. As for physically bumping into each other, one robot in 1024 could be dedicated (aside from it's router duties) the task of "traffic control", telling two robots when they get too close to each other (say within two meters) > > Another problem by building the array may be the amount of materials that > have to be transported. Say a solar cell weighs 2 kg/m^2, so the total > weight of the array is about 2 * 3.14E12 kg. That makes about 1.7E9 kg per > day, that's not nothing... in thinking about this, i was struck by the comment you made about the radius of the solar collector being about the same as the face of the moon, and i thought, what if instead of putting it (the collector) in orbit around the sun at Mercury's distance, why not just cover the surface of mercury with solar panels? (not too difficult if you have self-replicating robots) They could exist underground safely, and the maser array could be placed on the south pole of mercury (TC is below the ecliptic) Mercury would provide more than enough counter-weight for the beam, and the low gravity would assist the robots in maintaining the arrays > > >yeah, I think we are going to need that technology in many areas. > >Computer circuitry, accelerator coils, fusion containment coils anywhere > >you have a lot of energy, and no way to remove the heat. > > Computer circuits mostly need semi-conductors, so I think super-conductors Ever hear of a Josephson junction? > may not work there. But the other applications may be useful. Oh by the way, > super conductors can't conduct infinite currents... I don't know what their > maximum is though, I asked someone who worked with them but he didn't know > either, they used only small currents and small pieces. yes, i knew that, but that may be a limitation of technology, or is it fundamental? Keivn From popserver Thu Jan 18 03:06:29 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5616" "Wed" "17" "January" "1996" "18:56:27" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "97" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA13237 for ; Wed, 17 Jan 1996 16:55:04 -0800 (PST) Received: by maroon.tc.umn.edu; Wed, 17 Jan 96 18:56:27 -0600 In-Reply-To: <960116232114_44190980@mail02.mail.aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: KellySt@aol.com cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com Subject: Re: Engineering Newsletter Date: Wed, 17 Jan 1996 18:56:27 -0600 (CST) Kevin to Kelly > > Actually most companies only spend about %5 on research and development. The > rest goes to manufacturing. So I don't expect a big saving there. What about the management overhead? Most of the effort I ever saw in a company was the bean-counters and the vp types bucking for position getting in everyones way. I'll take the example of a bare-bones circuit board (it's what I know) If the job is to make a million of the same thing, then you have this big pyramid structure, but if the job is to only make one or two of something, and then be able to switch to a different board, then I say that a complete (waste recycling included) operation could be built in 20m by 20m by 3m and run by two, or three people. say another 20 by 20 by 3 for the computer chips, (I'm assuming truely standard things like resitors are stored in hold) and perhaps another 4 people for stuffing and testing, and any circuit board could be repaired or replaced. If you tried to run a company like that here on earth, you'd be eaten alive because on earth, the name of the game is profit. and the cheapest most reliable, easily replaced and quickly programable machine, is a human being. I can show you a million of them living in Mexico Citiy That would be fully functional as a worker in a PCB (Printed Circuit Board) factory inside a week. But on a ship like the Asimov, the name of the game is self-sufficiency and space-economy. In that environment, a Human being requires too much overhead (air, food water) and many jobs that are done by poeple on earth would be better done by robots on board the ship. Light bulbs can be re-made, and if they all have the same size and shape, (or only two or three kinds) then it's quite simple for one person to operate the equipment needed to clean the glass fragments, re-melt the glass, re-shape the bulb, apply the phosphor, attach the ends and fill it with sodium vapor. don't expect more than a few bulbs a day, but then, how many do you expect to burn out? Part of the reason we need 260 million people to support our industrial society, is because we have 260 million people who all need computers and light bulbs and a million other things, but if there are only a few hundred people, and the things they need are standardized, and there is little incentive to constantly upgrade (to a new and improved deoderant), then it can be done. Look at the Shakers, the Ammana Colonies, any of the _real_ communes in the sixties (some of which are still going quite strong) yes, the people lived at a lowered standard of living, but that is Tim's point I think. Look aropund your apartment. Many of the things you have, you could do just as well without. (if you are anything like me, that is) One of the Good things about places like Biosphere II is not what we will learn about closed-sytem ecologies (which will be argued no doubt), but what they teach us about our consumer society. What we learn to do without and what we find indispensible > > Later in this letter you mentioned this idea again and suggested if systems > were designed to be maintained they would require less replacement. To a > degree true. But after a couple decades everthing wears out; and the reason > we got used to throwing away things rather than repairing them, is its > cheaper and takes less effort. yes, this is true, cheaper and less effort. but repair is not impossible. And when the Nearest Wal-mart is billions of Kilometers behind you, and the weight of all the possible spares you will ever need. Is prohibitive, repair is the only rationale alternative. making a re-fillable pen, taking the time to make _every_ chip in a computer plugable (so they can be removed and re-seated with ease, instead of with a soldering gun) These things will allow us to drastically cut down the numbers of people needed to maintain the ship. > Well you have to call and end to it sometime. I figured a couple years in > systems would be all we could manage. Maybe a bit more than 3 years, but > certainly not anywhere near 10. We need to keep the crews round trip time > down below 30 years subjective (and not much more than that real time). I > was also expecting a maximum ship service life of about 40 years. With a 1g thrust there and back (don't ask me how) the subjective one-way trip time is 5 years. Another 5 years for return trip, and that leaves 10 - 20 years for exploration. The Earth time is 37-47 years, and that's just too bad for earth, there's only so fast a man can go (with current physics model) > Yeah, I'm begining to think we're doing this more out of habit then anything. > Maybe thats why Dave can never seem to get around to fixing things on LIT. > (I just got an E-mail from a new guy who wanted to join the newsletter and > saw my name in the on-line archive and asked what the status is.) > > Maybe we should work up a conclusion reprt or something. You can quit if you want to, But I'm never going to stop. This group has been a God-send to me. I've dreamt about this ever since I was 10. I intend to find a way. Expense is not a problem. Any cost can be justified if the reason is good enough. Finding strong evidence of a life-bearing world (one of the opening assumptions) would be just the reason to go, spare no expense. I could think of no better Heaven than to have these ideas used. "To have our design go where no one has gone before." "You may say I'm a dreamer, But I'm not the only one." (with thanks to Gene Rodenberry and John Lennon) Kevin From popserver Thu Jan 18 03:07:24 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1473" "Wed" "17" "January" "1996" "17:45:02" "-0800" "rddesign@wolfenet.com" "rddesign@wolfenet.com" nil "30" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id SAA21310 for ; Wed, 17 Jan 1996 18:29:45 -0800 (PST) Received: from sea-ts2-p18.wolfenet.com (sea-ts2-p18.wolfenet.com [204.157.98.136]) by wolfe.net (8.7.3/8.7) with SMTP id RAA21040; Wed, 17 Jan 1996 17:45:02 -0800 (PST) Message-Id: <199601180145.RAA21040@wolfe.net> X-Sender: rddesign@gonzo.wolfenet.com X-Mailer: Windows Eudora Version 1.4.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@InterWorld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Wed, 17 Jan 1996 17:45:02 -0800 (PST) I've sat back and watched this talk go on for sometime now.The phylosophical nature of this is interesting but not getting us to designing the ship. It is obivous we are having trouble coming up with a mission statement that nails down where we are going and for how long. I feel this discussion is just going to keep going around and around. Like Dave said. TC is arbitrary and the focal point for the ship design. Can we design a ship to take 1000, 2500 people? Can we insure we can have the proper and correct amounts of food and spare parts? Can we drive, ( stear ), the danmed thing? Can we stop it once we get it going? Can we get it started at all? The big problem as I see it is building a drive to get us to TC and back if we want to. The rest we can probably do with the technology we have today or in the next ten years. I know I know Nothing about the physics of all this that many of you are writing about. But I do know we are running in circles right now. How do we proceed? I don't have a clue. Just give me a hammer and some nail and I will start building the ship :-) You guys come up with the steam engin to push it. Maybe we need to concider several types of propulsion. kind of like a small sailboat that has sails, outboard motor and oars. Or just build the thing large enough to carry all the rocks we will need to toss into the ramscoop. Or, maybe we just might have to set our sights closer to home. Ric ( Kevin: No line about beads. :-) ) From popserver Thu Jan 18 17:58:26 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["234" "Thu" "18" "January" "1996" "08:46:48" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "9" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA26873 for ; Thu, 18 Jan 1996 06:45:25 -0800 (PST) Received: by maroon.tc.umn.edu; Thu, 18 Jan 96 08:46:48 -0600 In-Reply-To: <199601161659.AA11176@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Thu, 18 Jan 1996 08:46:48 -0600 (CST) Hey everybody, checkout the discovery of two jupiter-sized planets in the water zone. http://pio06.urel.berkeley.edu/documentation/photo.html while the planet itself might not contain life, the moons almost certainly could. Kevin From popserver Thu Jan 18 23:16:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9982" "Thu" "18" "January" "1996" "22:47:33" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "210" "Re: Engineering Newsletter" "^From:" nil nil "1" nil "Engineering Newsletter" nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA29195 for ; Thu, 18 Jan 1996 13:47:00 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA22112 (5.67b/IDA-1.5 for ); Thu, 18 Jan 1996 22:47:18 +0100 Message-Id: <199601182147.AA22112@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Thu, 18 Jan 1996 22:47:33 +0100 Tim replies to Kelly: >I can't see how staying would be safer. Unless you expect the drive system >to fail? Your still relying on the the same life support systems. I think I was expecting the drive to fail or blow up, but then again, if the risk was so high, it would have been likely to blow up on the outward journey. Since even a small risk (more than 1:1000) would not really be acceptable, you are probably right. >>I've doubts about that, a lot of things are unnessary renewed also a lot of >>effort is used to develop new things, if we would maintain the current >>level of technology and not innovate, we probably had a lot more spare time. > >Actually most companies only spend about %5 on research and development. The >rest goes to manufacturing. So I don't expect a big saving there. OK, but we don't need much manufacturing after the initial build up. It takes much less effort to keep what you have than to build something from scratch. Also a big amount of the 95% spend on manufacturing are the cost for raw materials, I expect the cost of mining raw materials will be less at TC because we can pick the easiest sites. No deep-sea oil drilling, most ores we need will be somewhere near the surface. I still don't see why it is not possible to scale things down. If you need 1 million people to feed 3 million people why can't you do with 100 workers for 300 people? I think a lot of organizational and social professions almost unneeded on TC because it is such a small community that doesn't have direct economic purposes. >Later in this letter you mentioned this idea again and suggested if systems >were designed to be maintained they would require less replacement. To a >degree true. But after a couple decades everthing wears out; and the reason >we got used to throwing away things rather than repairing them, is its >cheaper and takes less effort. Yes, but in those decades you would need much less new materials meaning a lot less work. The cheaper-throwing-away habit will not work on TC because it will take more effort to build a completely new object than to replace a single part. The reason that I mentioned this was not to say that things wouldn't wear out, but that the amount of work needed would be less since not all parts of the object have to be replaced each time. If you would throw away an object because one part breaks down, it would mean that the average life time of most objects would not be probably less than 3 years. ============================================================================ >> What I meant is that a new planet would give us more than Antarctica could, >> I don't mean that it could be a place to live, but a place to get much new >> scientific information. > >Agreed. For scientific purpose a alien biosphere would be a goldmine! But >it wouldn't help the crew to survive. No indeed, at least not for the first 20 years. But the mission would mainly be a scientific one. So you may want to stay longer at TC then the southpole just because there is much more to investigate. >>>That asumes the engines can provide the thrust equivelent to 1,000,000 times >>>their own weight. No engines now made can do that. The best fusion >>>engines I've heard specilated about can do 6 times there weight. We could >>>probably expect that to go up to 20, but not a million. >> >>OK, take 1 engine that could acclerate itself and 19 other engines, than the >>other 19 engines didn't need to accelerate themselves anymore so they could >>use all their power to accelerate the ship. > >That works for 20 to one. But you still have the weight of the fuel for the >one. Yes, but now you have 20 engines instead of 1 to push the fuel (the amount of fuel is not multiplied by 20 but by less than 20, depending on the weight of the engine). Here an anti-note (saying you may be right) I've tried setting up some formulas, from them it follows that you are right, I still don't see why though. (Formulas have a habit of not giving a good understanding) >> Storing fuel doesn't need much that much facilities. > >But it does take a lot of facilities to carry and move it. But do they need to be serviced all along the trip? >> I don't see why good >> planets without live could not be used. > >Probably any planet about earth size would have life (assuming its not >radically hot or cold. Wow, you are really optimistic. Or are you assuming that most earth-sized planets are too hot or too cold? Most Earth sized planets will have a dense atmosphere (not necessary oxigen rich). The ones that are cold are too far from their Sun or have too few greenhouse gasses. The ones that are too hot are too close to their Sun or have too many greenhouse gasses. Should too hot or too cold be a problem? Too hot maybe, it is easier to make something warm than to make something cold. But why are cold planets not good? By the way some people are suggesting on making a real atmosphere on Mars, wouldn't that dissolve constantly? On Earth gravity is high enough to keep its atmosphere, but on Mars the atmosphere is probably lost due to lack of gravity. >Right, thats why I keep talking about space colonies. Raw materials are far >easier to get at in space then on a planet. By mid 21st century we'll >probably be moving a lot of our heavy industry of earth and into space for >that reason (expect the third world to screem!), so I expect our starship >crew would not think of trying to get ore up off a planet. I'm not sure, would recycling not have a bigger influence on reducing the need for raw materials? Taking all the rubbish down means that the rubbish on Earth would increase, and we already have to much of that. >I was expecting to store standard groceries. Meat, eggs, milk, vegies, >breads, pasta all that stuff. With the exception of the emergency rations, >which would be optimized for high nutritian and low weight. Everything would >be as standard as possible. Thats why I used food weight numbers for home >consumers, not exploration or military missions. Huh, you just wrote: >To keep down the weight I was figuring NO FOOD RAISING on the ship. Instead >20 years of standard frozen foods in cryo, and 20 years of concentrated >rations. Or did you mean no cows and pigs? >Well you have to call and end to it sometime. I figured a couple years in >systems would be all we could manage. Maybe a bit more than 3 years, but >certainly not anywhere near 10. We need to keep the crews round trip time >down below 30 years subjective (and not much more than that real time). I >was also expecting a maximum ship service life of about 40 years. If the ship doesn't need to travel back anymore a lot of parts are unneeded, many of these parts are that of the engine, and these are the parts that wear out most fast and are most hard to replace. >> Huh, I can't follow you, am I right that you are against refueling or >> building beaming arrays? If so, than the trip may indeed become very >difficult. > >Beaming arrays yes. I was hoping we could get by on minning fuel for the >fusion systems and maybe launching it. You would need to mining and refine 1E10 kg of fusion materials, is that possible? I don't know, I have no oversight about these numbers, do you know what is acceptable? >I was also assuming a larger number of people then you are. Maybe only a 100 >people on the ground, but I expect total research team would be a thousand or >more. (Note the size of my ship.) Yes, I had never noticed that before. That means that all work can be done about 10 times faster. >> Yes, we have also very powerful medcines, take penicillin, it has a very >> broad range, and can kill many diseases at once, probably a lot of >> extraterrestial ones too. > >The only reason we can use anti-biotics at all is they trip up something >suttle in the bacteria they attack. Even a slight variation of that bacteria >species is uneffected. If the stuff effected something biologically >fundamental. It would kil the patent as well as the desease. As far as I knew, you have two kinds of anti-biotics, broad-spectre and small spectre. The small spectre have less side-effects but can kill fewer bacteria. The broad spectre can kill many different kinds of bacteria. But OK, I don't know that much about medcine, and I think neither do you. So I think we can't really discuss it well. I admit alien creatures will be different, but I just can't believe that it would be so different that we won't have a single clue how to fight them. I think we just have to disagree on this untill on of us has more hard data. >Yeah, I'm begining to think we're doing this more out of habit then anything. > Maybe thats why Dave can never seem to get around to fixing things on LIT. > (I just got an E-mail from a new guy who wanted to join the newsletter and >saw my name in the on-line archive and asked what the status is.) What did you tell him? Does he join? By the way I like this habit, I've learned a lot and given the project a lot of thoughts, before this I had never thought of all the problems that have arised. >Maybe we should work up a conclusion reprt or something. Yes, as soon as I have some time, I will make a start, my current timetable is real busy, I hardly have time to write these letters. >Well we never could come up with a solid reason why people wanted to go >there. It was just an assumption for the discussion that people would. > >So yes, maybe even if people could g, they wouldn't bother. We don't bother >to send people to the moon or Mars? ;) Sending people to Moon or Mars is cheaper, takes much less time of preparation and travel. The ship can be much smaller, no 20 year food supply is needed, even Earth controlled robots are a possibility. So all these things make it much more worth to go than TC. If we could go to TC and back in 5 years then the drive to go there may be much higher. Or if we could expand our lifespan by say 300 years. Tim From popserver Fri Jan 19 08:56:50 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6175" "Thu" "18" "January" "1996" "23:46:05" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "130" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA01798 for ; Thu, 18 Jan 1996 20:48:05 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id XAA06556; Thu, 18 Jan 1996 23:46:05 -0500 Message-ID: <960118234526_300534195@mail06.mail.aol.com> From: KellySt@aol.com To: zkulpa@lksu.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com cc: zkulpa@emin07.mail.aol.com Subject: Re: Engineering Newsletter Date: Thu, 18 Jan 1996 23:46:05 -0500 > > From KellySt@aol.com Wed Jan 17 05:30:37 1996 > > > > > [Zenon:] > > > Horrific and ruthless? > > > If you send them for such a trip against their will - > > > then you are possibly right. > > > But if they are willing? > > > There is a good ol' rule of Roman law: --- > > > > So, If you find someone willing to blow their brains out on camera, if the > > footage will be shone on the evening news. You don't think the news > > photagapher who says "sure, go for it" has any moral responsibility? > > > That is quite another story - publicizing somebody's > desire to make a grisly spectacle for no purpose except shocking others... > Anyway, if that someone wills to blow their brains - it is their, > so let them do it - one fool less will be a service to humanity... > Being the photographer, I would simply say that I'm not interested. > You see, would anybody climb at the window ledge > threatening to jump twenty stories down if nobody > will come with cameras, psychiatrist, negotiator, > fireman's brigade with long ladder and wailing siren? > And 100% of such "desperados" somehow becomes easily > persuaded not to jump (after he is sure all the media > gave enough coverage of his attempt...). > So do not mince matters, Kelly... You seem to be arguing my point. You are proposing to be the mission control/cameraman eager to send crews out to die on the frountier for fame and fortune. > > [Zenon:] > > > Besides, everybody must die some time - > > > what is that real & shocking difference between dying > > > in Antarctica and in Sometown, Montana? > > > With the starflight, another important factor is added: > > > the return flight is long (of the order of at least 10 years, say), > > > thus those returning will have only few years to enjoy > > > their medals on Earth, not to say of the boring years > > > on the ship with nothing exciting to do (except betting > > > if the next ship gear failure will be fatal...) > > > and rather risky - the probability > > > of irreparable failure of the ship during the flight > > > is much larger than the failure of the outpost base. > > > I, frankly, would prefer to stay at the outpost. > > > It might significantly increase my life expectance... > > > > You have a choice of 10 years in the ship betting on its systems not failing > > on its return flight. Vs the rest of your life in that same ship parked in > > the system, or a base built out of the ships parts, still better the systems > > don't fail. Unless your assuming you'll die in less than 10 years of natural > > causes. I can't see how you could take the return flight as safer. > > > Return flight is much less safe than living at the base, Kelly. > That collossal engine, with all its terawats boiling inside - > ready either to blow out or to stall, rather worn out after > years and years of the first half of the flight. > No resources to find in the void, nor means to stop and search... But its a simpler system then the life support, and only needs to keep working for a few months at eiather end of the trip. Life support would need to work for decades, and even if it does how long will the crew last in a ship without cutting edge medicine or (at the end) anyone left healthy enough to maintain and operate the remaining systems. Personally I can't think of too many worse ways to go then locked in a dieing ship with a dieing crew, better which of the two would lose it first. > > In any event its accademic. No political organization would be allowed to > > support or allow such a flight. Since such a flight can't be done without > > them in the next 50 years. The option, ruthless as it is, is closed. > > > Political organizations (and opinions) are not laws of nature, > but emanations of people's opinions and attitudes. > If they (the people) have such attitudes as you seem to propagate > in our discussion, that it's not surprising that they possibly > will not "support or allow" ANY flight (that's risky, you know - > untested technology, not complying to these mountains of government > rules and regulations of safety, no guarantee of safe return, > high probability of accidental loss of life, > probably far larger than in Kuwait...). > So, if we want to go to the stars at all, > we must fight off such attitudes. > Not to say of other resons to do so. Why fight off such an attitude? Your proposing throwing away a crew like they were expendable parts. All for the convenence of a flashy, but non crytical, program. > I wonder - Lindbergh would be certainly not allowed to cross > the Atlantic - in his personally constructed and build plane, > without all those attestations and safety inspections, completely > on his own, with no detailed progress reports to the government, > etc., etc. - surely a suicide mission... > > If such attitude really prevails, farewell the future of humankind, > either among the stars or right there on Earth... Linbergh had a comercial ship customized for his purposes and had every intention of geting there alive. He got sponcership because everyone was fairly sure he wasn't a suicvidal ameture who would take stupid unnessisary risks. Comes the time we blithly throw away a few hundred people to save ourselves a little time and trouble, for a cause of no urgent critical importance, humankind doesn't deserve. As you may remember I was working in NASA shuttle flight planing when the Chalenger (almost exactly ten years ago) ripped itself apart in mid air. Largely because some political types desided not making waves and bad PR was more important than a few astronauts lives. After that a lot of political types got fired and a lot of astronauts quit. NASA had violated a cardinal rule of test pilots. They'ld risk their lives if it was important enough, but the people on the ground had to keep them informed and do everything possible to keep them alive. Doing a cost benifit analysis and deciding their lives arn't cost effective, doesn't cut it. I don't know what kamakazis you could get for such a flight, but they'ld be the dregs of this race, and I'ld be assamed for them to be my representatives to the stars. Kelly From popserver Fri Jan 19 08:57:56 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6914" "Fri" "19" "January" "1996" "00:33:41" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "137" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA04559 for ; Thu, 18 Jan 1996 21:33:39 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id AAA06656; Fri, 19 Jan 1996 00:33:41 -0500 Message-ID: <960118234616_300534638@emout04.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 00:33:41 -0500 > > Kevin to Kelly > > > > Actually most companies only spend about %5 on research and development. The > > rest goes to manufacturing. So I don't expect a big saving there. > > What about the management overhead? Most of the effort I ever saw in a > company was the bean-counters and the vp types bucking for position > getting in everyones way. ---- You'll have most of the same kind of people on the ship. Assuming everyone isn't as worthless you could eliminate a lot of them. Given better tech, and limited production, you could eliminate a lot more. I'ld be willing to assume we could drop the threshold number down by a factor of ten or a hundred. That still means you need a tens to hundreds of thousands of people. Which is too many. >---- Part of the reason we need 260 million people to support our > industrial society, is because we have 260 million people who all need > computers and light bulbs and a million other things, but if there are > only a few hundred people, and the things they need are standardized, and > there is little incentive to constantly upgrade (to a new and improved > deoderant), then it can be done. Look at the Shakers, the Ammana > Colonies, any of the _real_ communes in the sixties (some of which are > still going quite strong) yes, the people lived at a lowered standard of > living, but that is Tim's point I think. Look aropund your apartment. > Many of the things you have, you could do just as well without. (if you > are anything like me, that is) None of those groups are self suficent now here (all but the most fanatic need hospitals and such). I'm geting quite familure with Ammish since their is a big a troblesome colony of them near my home. You also seem to skip over the fact that they arn't trying to live in a starship, orbiting in an alien starsystem, runing a high tech survey mission. This isn't little house on the prarie. All that high tech exotica, from nav systems to artificial, computer controled life support, is the thin wall between them and death. They will not be able to live off the land, hunt for game, or get by with nothing more high tech than a wood buggy and furniture. If it goes wrong; they can't ask for help from the next village or ship from europe. > One of the Good things about places like Biosphere II is not what we will > learn about closed-sytem ecologies (which will be argued no doubt), but > what they teach us about our consumer society. What we learn to do > without and what we find indispensible Did you ever lok at all the high tech, high maintenence gear it took to keep Bio-shpere going? Oh, and it wasn't enough! > > > > Later in this letter you mentioned this idea again and suggested if systems > > were designed to be maintained they would require less replacement. To a > > degree true. But after a couple decades everthing wears out; and the reason > > we got used to throwing away things rather than repairing them, is its > > cheaper and takes less effort. > > yes, this is true, cheaper and less effort. but repair is not impossible. > And when the Nearest Wal-mart is billions of Kilometers behind you, and > the weight of all the possible spares you will ever need. Is prohibitive, > repair is the only rationale alternative. making a re-fillable pen, > taking the time to make _every_ chip in a computer plugable (so they can > be removed and re-seated with ease, instead of with a soldering gun) > These things will allow us to drastically cut down the numbers of people > needed to maintain the ship. They will also drasticly cut the relyability of the system on the ship. > > Well you have to call and end to it sometime. I figured a couple years in > > systems would be all we could manage. Maybe a bit more than 3 years, but > > certainly not anywhere near 10. We need to keep the crews round trip time > > down below 30 years subjective (and not much more than that real time). I > > was also expecting a maximum ship service life of about 40 years. > > With a 1g thrust there and back (don't ask me how) the subjective one-way > trip time is 5 years. Another 5 years for return trip, and that leaves > 10 - 20 years for exploration. The Earth time is 37-47 years, and that's > just too bad for earth, there's only so fast a man can go (with current > physics model) Earth pays the bills. If it doesn't serve their intrest, it wount happen. The crytical time is that it would take roughly 15 years to get there and start making reports. First report back to earth in mission year 25 or something. That may not be quick enough for this kind of BIG money project. Also 10-20 years is way to long in system. You're people are going to burn out, and your support ships are going to be shot. 5 years should alow you to bring back as much data as the ship could carry. Much more than that and your trying to cover every detail, which would take centuries. Oh, and we don't have a clue how to get a ship 1G'ing up to light speed in any practical sence, and no idea at all on how to stop it. > > Yeah, I'm begining to think we're doing this more out of habit then anything. > > Maybe thats why Dave can never seem to get around to fixing things on LIT. > > (I just got an E-mail from a new guy who wanted to join the newsletter and > > saw my name in the on-line archive and asked what the status is.) > > > > Maybe we should work up a conclusion reprt or something. > > You can quit if you want to, But I'm never going to stop. This group has > been a God-send to me. I've dreamt about this ever since I was 10. I > intend to find a way. ----- Yeah, me too. But we're runing out of ideas and members. Most of the last month or three all we've really done is rehash old ideas. Maybe if we can get the LIT sight upgraded with more info and stuff we can attract people with new ideas. We used to have hundreds of people lurking out there, and 4-8 sizable weekly newsletters. Now its just a handfull of us, and even Daves (the founder) can't work up much enthusiasm for it. Maybe in wirking up a summary report we might realise something we overlooked. But now we're getting to the point where were running around in circles. I'm afraid we'll just drop of the mail loop and we won't even have worked up a summary report that people can start up from. > ---- Expense is not a problem. Any cost can be > justified if the reason is good enough. Finding strong evidence of a > life-bearing world (one of the opening assumptions) would be just the > reason to go, spare no expense. I could think of no better Heaven than > to have these ideas used. Spare NO expence? What exactly would justify unlimited funds for this? Even avoiding that, we could backrupt the planet and still not pay for some of the ideas we've been tossing around. They ideas woun't be used ifthey won't work. From popserver Fri Jan 19 08:58:32 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2218" "Fri" "19" "January" "1996" "01:10:43" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "44" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id WAA06735 for ; Thu, 18 Jan 1996 22:10:08 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id BAA03419; Fri, 19 Jan 1996 01:10:43 -0500 Message-ID: <960118234558_300534486@emout05.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, hous0042@maroon.tc.umn.edu, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, David@interworld.com, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 01:10:43 -0500 > I've sat back and watched this talk go on for sometime now.The phylosophical > nature of this is interesting but not getting us to designing the ship. It > is obivous we are having trouble coming up with a mission statement that > nails down where we are going and for how long. I feel this discussion is > just going to keep going around and around. > Like Dave said. TC is arbitrary and the focal point for the ship design. > Can we design a ship to take 1000, 2500 people? > Can we insure we can have the proper and correct amounts of food and spare > parts? > Can we drive, ( stear ), the danmed thing? > Can we stop it once we get it going? > Can we get it started at all? > > The big problem as I see it is building a drive to get us to TC and back if > we want to. The rest we can probably do with the technology we have today or > in the next ten years. > > I know I know Nothing about the physics of all this that many of you are > writing about. But I do know we are running in circles right now. How do we > proceed? I don't have a clue. Just give me a hammer and some nail and I will > start building the ship :-) You guys come up with the steam engin to push > it. Maybe we need to concider several types of propulsion. kind of like a > small sailboat that has sails, outboard motor and oars. Or just build the > thing large enough to carry all the rocks we will need to toss into the > ramscoop. Or, maybe we just might have to set our sights closer to home. > Your essentially right. Other than the drive systems the rest of the ship is straightforward. BIG, but given a large space industrial infastructure (a reasonable expectation for 2050) we could build it. The drive system is another matter. We've come up with no credible near light speed drive. The closest we've got is the Microwave-sail/Mars system, and it frankly isn't do-able. So we cant get to T.C. in a use-able time period. We have ideas that could get us to a fraction (.1 to maybe .3) of light speed at considerable expense, but that won't get us to T.C.. I'm working up a draft list of the general ideas for missions, drives, etc.. (IN BRIEF!). When I finish it I'll send it around for review and critique. Kelly From popserver Fri Jan 19 08:58:44 GMT 1996 X-VM-v5-Data: ([nil nil nil t t nil nil t nil] ["14653" "Fri" "19" "January" "1996" "01:40:38" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "266" "Fwd: LIT e-mail discussion group " "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id WAA08348 for ; Thu, 18 Jan 1996 22:43:47 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id BAA27312; Fri, 19 Jan 1996 01:40:38 -0500 Message-ID: <960119001927_120961810@mail06.mail.aol.com> MIME-Version: 1.0 Content-type: multipart/mixed; boundary="PART.BOUNDARY.0.17542.mail06.mail.aol.com.822028764" From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com cc: kgstar@most.fw.hac.com Subject: Fwd: LIT e-mail discussion group Date: Fri, 19 Jan 1996 01:40:38 -0500 --PART.BOUNDARY.0.17542.mail06.mail.aol.com.822028764 Content-ID: <0_17542_822028767@mail06.mail.aol.com.162778> Content-type: text/plain HI here is the first post by the new guy. I'll forward him the last few of our posts. Sory, I'm burned out replying to all you guys posts, you you folks can introduce one another. Kelly --------------------- Forwarded message: From: bmansur@oc.edu (Brian Mansur) To: KellySt@aol.com ('KellySt@aol.com') Date: 96-01-18 20:45:47 EST What does Cc mean anyway? Thanks for responding to my first ever e-mail Kelly! For the group's information, I'm a junior pre-med biochemistry major at Oklahoma Christian University of Science and Arts (it's a long name, I know) who hates the math aspect of most anything but has seen too many Star Trek and Babylon 5 episodes to not be interested in LIT's starship design project. Down to business. I'd love to jump in on the discusion that you guys have been running since LIT's server shut down. In the last few months I've been reviewing the newsletters and the ideas surrounding the propulsion problem. I'll probably have at least a little to say here. To begin with, I'd like to remind everyone on the Starship Design Project that our #1 problem in the propulsion field is how to slow down. Everything else is comparatively a piece of cake because the ship can be launched using an external propulsion system or an externally fueled counterpart such as a near solar system fuel track. The problem is how to fuel a ship when it is 12 light-years away. A quick note to Kevin Houston is that I have a hard time seeing his beam scheme reaching across the interstellar distances to connect with his famous MARS microwave toaster oven. The MARS idea works fine as any near home if used for a launch. Unfortunately, the power line just has to stretch too far to be feasible to stop (now go build the thing just to show me I'm wrong .. . . please :-). The only possible fix that I can see for any sort of light-years distant external fueling, be it for Relativistic Particle Beam Propulsion (RPBP), Photonic Pressure Propulsion (PPP), Microwave beaming (MARS), or fuel track laying for Ram Augmented Ion Rockets (RAIR), is to have some sort of network of refocusing or redirecting stations all along the path to the star. If this system involves power beaming, then there are going to be some serious losses in energy during the transfer. For example, a refocusing network for the lightsail could use a set of connected mirrors configured like a reflective telescope. One mirror would be the huge collector and the smaller opposable mirror would refocus the beam. HERE COMES ASCII ART :-) ------>------------>----------->-------------\ LIGHT RAYS <------- \ <------- | -------------------->----------->---[<-->-------->----------->--------->---- ----->--------->SHIP THESE RAYS ARE <------- | LOST TO 2ND MIRROR <------- / PRIMARY ------>------------>----------->_------------/ MIRROR LIGHT RAYS I'm posting a BMP file of this idea right here just to see if it works. Should be easier on the readers' sanity as I've heard complaints about this somewhat limited artform. How's the color? [[ E-ART.BMP : 4688 in E-ART.BMP ]] Unfortunately, some power would be lost as it hit the secondary mirror (we could make it one-way transparant if it were glass-like) and there will certainly be losses due to irregularities in the mirror's surface and the reflective material (silver is the best I can think of and that ain't cheap). The two would have to be connected as well to prevent any net movement. A series of Fresnel plates could serve as a MARS refocusing network but I have no idea as to how efficient that would be. I've completely ruled out an ionized particle beam refocusing network for Robert Zubrin's Magsail as perterbations in the matter stream would increase dramatically with distance. This would balloon the number of refocusing stations. It may also prove impossible to use an pre-ionized relativistic particle stream to push a magsail very far at all because, well, just look at what the sun does to all of the ionized gas that it spews out. The gas follows the shifting magnetic field of the star. I still have hope that this can be compensated for but then I also had hope that man would have returned to the moon by now. Zubrin suggested that the particle stream be neutral on the way to the magsail and that a laser carried on board could be used to ionize it. I would suggest using a laser that was NOT on board because, as someone pointed out in ARC29, it would take a terawatt to ionize 100 sq. meters, not accounting for conversion efficiencies of energy into a photon beam. Even if we could design a transfer efficient refocusing network, we would still have to find a way to get these stations into place for a cheap cost. Judging by what Forward (or whoever worked on lightsails) said about refocusing lenses being around the orbit of Neptune, we'd need thousands of refocusing stations placed all the way to 30 AU's from Tau Ceti. Kind of defeats the purpose of finding a cheap solution. On the other hand, if it could be done. . . . I know that I am jumping from topic to topic here. Its just that I've got a lot on my mind that I want to get to you guys before I have to face my Calculus homework. By the way, you may be wondering where we are getting the power for these propulsion designs. From the billions of 10 kilometer square power stations out between Mercury and Venus, of course. They were built by largely autonomous robot farms (the reproduce and prosper like any good ant farm) on Mercury and the Moon. To keep up the number of stations these two planets process dozens of solar collectors each second. Power is beamed to anyone in and around the solar system who will pay the human overseers' wages. Switching gears here, I was going over some information on the Deadalus probe in a book called "Bound for the Stars" by S.J. and B. Adleman. Anyway, the book said that the design was supposed to have a 15 to 1 fuel to ship ratio that would get a 500 ton payload to just over .10c. Using that as the working number to beat, and knowing that the probe uses greater than twenty-thousand tons of 3He (not exactly a common isotope), I tried figure out how we could make that monster more fuel efficient. The ideal scheme would be to launch the fuel from Sol to the ship. Or better yet, to launch the ship to the fuel that is already on route. Better still, perhaps, do both. Here is what I meam. Whatever fuel or reaction mass we need, we bundle up in tanker drones. We put a magsail on the tank along with about a dozen redundant homing beacons with LONG lasting energizer batteries. We then launch enough fuel to slow down a 250,000 ton starship by .01c. By the way, 250,000 tons is my opinion of the ballpark weight limit that would be account for enough equipment and shielding to support a 100 or so person crew. Not all of the 250,000 tons of the launch vehicle is necessarily unfueled. Anyway, the first tanker will actually have to carry enough fuel to slow the ship as much as .1c, but thems is the breaks (I actually made a semi-descent pun without meaning to). This first tanker will also be traveling only as fast as it can slow the starship to a full stop at the next gas station in Tau Ceti's Kupier belt. The other smaller tankers will be launched during the appropriate windows that will let them reach a position along the flight path that allow a starship to catch up with them, find them in deep space via the homing beacons, dock with them, and finally use their fuel to slow to the speed of the next tanker and repeat the process. This means that the overall deceleration phase will be fairly lengthy. Since every kilo on the starship will count against us, we need the ship to be as light as possible during deceleration. That's why we are bothering to wait a hundred years for our forward breaking tanker to reach its position before launching the actual starship. But note that if Mankind can afford to magsail launch a 1000 ton ship as envisioned by Zubrin, I'm betting that the technology will already be good enough and cheap enough to launch a 250,000 ton ship (which is about as heavy as it will need to be if we want to put 10 tons per sq. meter of shielding on the habitat). By the way, the whole shielding problem is still of some concern to me. How much do we really need when flying at relatavistic speeds? I think that we should should pray to God that he doesn't put a lot of little paint flecks sized particles between us and the stars or else our ship will run into them and they will cause dents way bigger than seen on the space shuttle window. One of "Bound for the Stars" suggestions for protection against smaller debris was to put a dust cloud/bag of some sort ahead of the ship. It would act like a forward atmospheric shield. Back to weight efficiency in the ship's design. If the magsail is big enough to effect any sort of deceleration by using the interstellar ionized gas, then we should turn the ship around. To do it, we fold the sail like an umbrella, turn, and redeploy it. Whatever kind of deceleration it produces will probably go virtually unnoticed by the crew and may be compensated for in how we rotate our habitat for artificial gravity and or by how it is laid out internally. Exactly how we want to produce artificial gravity will be determined in a later discusion. Speaking of the habitat. It is obviously going to take up the bulk of the shielding although it would be nice to protect our drive system and power reactors if at all possible. I'm thinking that we might want to mail the ship to Tau Ceti as a some assembly required package. We could, pack everything but the magsail, antenna, scientific instruments, and attitude thrusters inside a heavily sheilded cylinder with the habitat on the outer decks. Hopefully it won't end up weighing as much as Babylon 5 (2.5 million tons of spinning metal . . . . all alone in the night). The only viable solution that I can come up with to keep the shielding costs from getting too far out of control is to use fuel/reaction mass as shielding. Also we could send some fuel/reaction mass/shielding after the ship. This would require putting an extra engine on either the fed express tanker or the starship. For the cruising phase of the flight, we can afford to make a habitat that is spacous and comfortable. As soon as we want to slow down, however, we'll have to stuff the crew into a collection of cramped, space economized, modularized, trailer car-like habitats that fit into the cargo bay of the space shuttles that we'll use to explore planet surfaces. This deceleration storm shelter complex will be much easier to shield and, after we jetison (how do you spell that word?) the cruising hab, will drop the ship weight by tens if not hundreds of thousands of precious tons because the fuel that was formerly shielding for our interstellar space hotel will then be used to slow the ship to reach the first tanker drone. We'll assume that the deceleration phase is more or less 10 m/s and is relatively constant between tanker dockings. You've probably noticed that I don't hold out much hope for getting our crew back to Sol in their life-times. Over the last few days I've come up with a mission plan called for a starship named U.S.S. LEGACY. It is to be the pioneering manned starship of a colonization effort. Other ships like the U.S.S. HERITAGE will follow but that's my little fantasy. For now I'll play with the ASIMOV. In my opinion, if we've figured out how to get to another starsystem, we'll probably have figured out how to create self-sustaining colonies on even Luna-like worlds. On the other hand, even with extensive automation and self-reproducing robots, I'm not bothering (in today's discussion) to assume that we could hope to put together a launching system for a manned explorer ship using a less than 1000 person crew. We should, however, be able to carry enough equipment to set up a viable colony that will one day create a spacefaring civilization large enough to support another RPB network that could stop near light-speed fast ships from Sol. I realize that the LIT charter said (or implied) that the mission of the ASIMOV is supposed to be exploration and evaluation of a potentially habitable system. If we become technically sophisticated enough to send a manned ship to Tau Ceti, the robotics involved in producing that ship and its support systems at Sol will probably be more than adequate to send robot explorers on something like the Daedalus probe. If Tau Ceti turns out to be a dud, we wouldn't have then expended precious resources making a starship that will get a crew 12 light-years out to the middle of nowhere and back. The counter-arguement is that we would at least have the experience of having gone to the stars, just as Apollo gave us the experience of going to the moon and provided the plot for one excellent suspense/drama/documentary called Apollo 13. It's a sobering reminder of the dangers of spaceflight. One tiny defect almost killed 3 Americans. But this going to Tau Ceti is a lot more complicated than going Luna and back and I just don't see how to get the crew home in their lifetime. We might as well rename the ship VOYAGER and consider it lost in space. By the way, we all know that a one way mission where the crewmembers live out their natural lives at Tau Ceti is an option, but not a particularly pleasant or moral inspiring one. It is late and I need to do Calc. I imagine that someone has come upon these ideas long before me but I hope that what I've written has helped to refocus some thoughts (II Peter 1:13 I think it is right to refresh your memory as long as I live in the tent of this body). Thanks for taking the time to read This, My Core Dump. I invite comments to be sent by bus, plane, train, automobile, phone, mail or e-mail. The e-mail address (as far as I know) is: bmansur @OC.edu My phone number is 405 - 425 - 6103 Mail can be sent to Brian V. Mansur 2501 E. Memorial Rd. Box 11000 Oklhoma City, OK 73136-1100 The following binary file has been uuencoded to ensure successful transmission. Use UUDECODE to extract. From popserver Fri Jan 19 09:57:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["637" "Fri" "19" "January" "1996" "04:52:07" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "19" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA05479 for ; Fri, 19 Jan 1996 01:51:53 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id EAA09004; Fri, 19 Jan 1996 04:52:07 -0500 Message-ID: <960118234547_300534380@emout06.mail.aol.com> From: KellySt@aol.com To: zkulpa@lksu.ippt.gov.pl, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com cc: zkulpa@emin09.mail.aol.com Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 04:52:07 -0500 > From KellySt@aol.com Wed Jan 17 05:25:15 1996 > > Obviously if the > organization is doing something critical its usually kept minimally gummed > up. But given that this project can't in anyway be considered critical, it > would be unlikely to get clear of that. > >>So - let us make it critical! >>Say, poke the Sol a little to show symptoms of becoming a >> nova... ;-)) >> Seriously, I am afraid it will become critical after some time But certainly this flight could help any crytical problem, and it will be a very long time before star travel is more than a luxury. But by then, we'll have much better equipment. Kelly From popserver Fri Jan 19 09:57:24 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11235" "Fri" "19" "January" "1996" "04:52:46" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "258" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA05546 for ; Fri, 19 Jan 1996 01:52:38 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id EAA09531; Fri, 19 Jan 1996 04:52:46 -0500 Message-ID: <960118234634_300534786@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 04:52:46 -0500 > > Tim replies to Kelly: > > >>I've doubts about that, a lot of things are unnessary renewed also a lot of > >>effort is used to develop new things, if we would maintain the current > >>level of technology and not innovate, we probably had a lot more spare time. > > > >Actually most companies only spend about %5 on research and development. The > >rest goes to manufacturing. So I don't expect a big saving there. > > OK, but we don't need much manufacturing after the initial build up. It > takes much less effort to keep what you have than to build something from > scratch. > Also a big amount of the 95% spend on manufacturing are the cost for raw > materials, I expect the cost of mining raw materials will be less at TC > because we can pick the easiest sites. No deep-sea oil drilling, most ores > we need will be somewhere near the surface. Raw materials will be in space. MOst of the best ore beds on earth are crashed asteroids. We can go to the source! Its not allways easier to maintain an established thing then to build a new thing to replace it. Often its much more expensive to maintain the old thing then replace it. Thats especially true of light high performance things like space ships, trucks, and cars. We could be a bit more effocent then people are here on earth, but not dramatically so. If we could, people would do that here to save money. Actually since we'ld be doing things in small coustom bunches, not large mass production lots like back here on earth. We'll be far less efficent in T.C. space. > > I still don't see why it is not possible to scale things down. If you need 1 > million people to feed 3 million people why can't you do with 100 workers > for 300 people? Actually it takes a couple dozen people to feed 3 million people. But to maintain a socyiety it takes millions of differnt professions. You cant train 100 people, to each do 60,000 professions and do them well. And we arn't in a good position to deal with a lot of sloppy workmanship. > I think a lot of organizational and social professions almost unneeded on TC > because it is such a small community that doesn't have direct economic purposes. > > >Later in this letter you mentioned this idea again and suggested if systems > >were designed to be maintained they would require less replacement. To a > >degree true. But after a couple decades everthing wears out; and the reason > >we got used to throwing away things rather than repairing them, is its > >cheaper and takes less effort. > > Yes, but in those decades you would need much less new materials meaning a > lot less work. The cheaper-throwing-away habit will not work on TC because > it will take more effort to build a completely new object than to replace a > single part. The reason that I mentioned this was not to say that things > wouldn't wear out, but that the amount of work needed would be less since > not all parts of the object have to be replaced each time. Why do you say, a few decades? What would change after 30 or 70 years? Are you expecting better ships or something? > > ============================================================================ > >>>That asumes the engines can provide the thrust equivelent to 1,000,000 times > >>>their own weight. No engines now made can do that. The best fusion > >>>engines I've heard specilated about can do 6 times there weight. We could > >>>probably expect that to go up to 20, but not a million. > >> > >>OK, take 1 engine that could acclerate itself and 19 other engines, than the > >>other 19 engines didn't need to accelerate themselves anymore so they could > >>use all their power to accelerate the ship. > > > >That works for 20 to one. But you still have the weight of the fuel for the > >one. > > Yes, but now you have 20 engines instead of 1 to push the fuel (the amount > of fuel is not multiplied by 20 but by less than 20, depending on the weight > of the engine). No the fuel is still multiplied by tweenty. Thats the whole point. > Here an anti-note (saying you may be right) > I've tried setting up some formulas, from them it follows that you are > right, I still don't see why though. (Formulas have a habit of not giving a > good understanding) > > >> Storing fuel doesn't need much that much facilities. > > > >But it does take a lot of facilities to carry and move it. > > But do they need to be serviced all along the trip? Yes, but not that much when they are shut down. More importantly they have to be carried. > >> I don't see why good > >> planets without live could not be used. > > > >Probably any planet about earth size would have life (assuming its not > >radically hot or cold. > > Wow, you are really optimistic. Or are you assuming that most earth-sized > planets are too hot or too cold? Earth got life very quickly after it cooled. Mars may have life. Then their is Venus whose crust is wrong which makes it to hoot. What does that give you for odds? And is it an average sample? Given the extreams of temperature, radiation, chemistry, etc.. that life lives in on earth. (icewater, nuclear reactor cores, water hundreds of centigrade above 0, deserts) I'ld expect to find life almost anywhere. > Most Earth sized planets will have a dense atmosphere (not necessary oxigen > rich). The ones that are cold are too far from their Sun or have too few > greenhouse gasses. The ones that are too hot are too close to their Sun or > have too many greenhouse gasses. Venuses temp is NOT due to its atmosphere. Its due to its crust, its a fraction of the thickness of earth crust and doesn't insulate well enough to keep the surface cool. > Should too hot or too cold be a problem? Too hot maybe, it is easier to make > something warm than to make something cold. But why are cold planets not good? You can get just as dead in liquid air as in liquid metal. Eiather way your pushing equipment hard, and without a good survival odds when it fails. > By the way some people are suggesting on making a real atmosphere on Mars, > wouldn't that dissolve constantly? Yes it would. But it may be stable for a couple thousand years. Or you could artificially renew it as it blows away. Hard part it gravity. Humans need it to stay healthy. > >Right, thats why I keep talking about space colonies. Raw materials are far > >easier to get at in space then on a planet. By mid 21st century we'll > >probably be moving a lot of our heavy industry of earth and into space for > >that reason (expect the third world to screem!), so I expect our starship > >crew would not think of trying to get ore up off a planet. > > I'm not sure, would recycling not have a bigger influence on reducing the > need for raw materials? Taking all the rubbish down means that the rubbish > on Earth would increase, and we already have to much of that. For ecology purposes moving heavy industry off planet would do more than anything else to ease ecology strain. Of course their are international political and cultural problems with that (proably a couple of wars with the third world). Stuff can't be recycled forever. After a while it just doesn't make any sence. Right now we in the (throw it all away) U.S. have litle real problem with waste disposal (though an incredible amount of political problems). about 80%-90% of our garbage is paper and similar compustables. The small fraction of metals and plastics %5ish, can be broken down or shiped into space if you crazy enough. Besides if the industry moves off planet to get to the resources, the materials to be recycled would need to be shiped up to be recycled anyway. > >I was expecting to store standard groceries. Meat, eggs, milk, vegies, > >breads, pasta all that stuff. With the exception of the emergency rations, > >which would be optimized for high nutritian and low weight. Everything would > >be as standard as possible. Thats why I used food weight numbers for home > >consumers, not exploration or military missions. > > Huh, you just wrote: > > >To keep down the weight I was figuring NO FOOD RAISING on the ship. Instead > >20 years of standard frozen foods in cryo, and 20 years of concentrated > >rations. > > Or did you mean no cows and pigs? No I ment no food raiseing. Oh, you can have a couple of tomato plants in your apartment for recretion. But farm systems weigh too much if your only going out for a couple of decades.. > >Well you have to call and end to it sometime. I figured a couple years in > >systems would be all we could manage. Maybe a bit more than 3 years, but > >certainly not anywhere near 10. We need to keep the crews round trip time > >down below 30 years subjective (and not much more than that real time). I > >was also expecting a maximum ship service life of about 40 years. > > If the ship doesn't need to travel back anymore a lot of parts are unneeded, > many of these parts are that of the engine, and these are the parts that > wear out most fast and are most hard to replace. > > >> Huh, I can't follow you, am I right that you are against refueling or > >> building beaming arrays? If so, than the trip may indeed become very > >difficult. > > > >Beaming arrays yes. I was hoping we could get by on minning fuel for the > >fusion systems and maybe launching it. > > You would need to mining and refine 1E10 kg of fusion materials, is that > possible? I don't know, I have no oversight about these numbers, do you know > what is acceptable? Minning seems easier then processing power converters and microwave systems. Don't know where to find that much ore off hand, but in space extreamly rich resources are common. > >I was also assuming a larger number of people then you are. Maybe only a 100 > >people on the ground, but I expect total research team would be a thousand or > >more. (Note the size of my ship.) > > Yes, I had never noticed that before. That means that all work can be done > about 10 times faster. > > >> Yes, we have also very powerful medcines, take penicillin, it has a very > >> broad range, and can kill many diseases at once, probably a lot of > >> extraterrestial ones too. > > > >The only reason we can use anti-biotics at all is they trip up something > >suttle in the bacteria they attack. Even a slight variation of that bacteria > >species is uneffected. If the stuff effected something biologically > >fundamental. It would kil the patent as well as the desease. > > As far as I knew, you have two kinds of anti-biotics, broad-spectre and > small spectre. The small spectre have less side-effects but can kill fewer > bacteria. The broad spectre can kill many different kinds of bacteria. But > OK, I don't know that much about medcine, and I think neither do you. So I > think we can't really discuss it well. I admit alien creatures will be > different, but I just can't believe that it would be so different that we > won't have a single clue how to fight them. I think we just have to disagree on this untill on of us has more hard data. I know ther are dozens of differnt anti-biotics each tailored to various things (and most becoming ineffective), but I don't know much more than that. Why would you think we could fight them? Kelly From popserver Fri Jan 19 17:00:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1285" "Fri" "19" "January" "1996" "08:22:48" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "38" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA10920 for ; Fri, 19 Jan 1996 05:24:18 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA04172; Fri, 19 Jan 96 08:25:46 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004103; Fri Jan 19 08:24:01 1996 Received: by most (4.1/SMI-4.1) id AA02126; Fri, 19 Jan 96 08:23:58 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002103; Fri Jan 19 08:22:49 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA26568; Fri, 19 Jan 96 08:22:46 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: Steve VanDevender Cc: KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com, kgstar@most.magec.com Subject: Re: Fwd: LIT e-mail discussion group Date: Fri, 19 Jan 1996 08:22:48 -0500 At 1:14 AM 1/19/96, Steve VanDevender wrote: >Hey, could we NEVER EVER mail 480,000 byte uuencoded BMP files to other >people ever again? I only have so much disk space for my mail. > >At least use a format like GIF or JPG that does some compression. BMP >is yet another of Microsoft's evils. At 1:18 AM 1/19/96, Steve VanDevender wrote: >I just unpacked that ridiculously huge .BMP file, cropped it to just the >part of the bitmap that contained image details, and saved it as a .GIF >file. It was 4823 bytes. Next time, think before you send this kind of >crud around. May I point out a certain line in said message > Brian Mansur) > To: KellySt@aol.com ('KellySt@aol.com') > Date: 96-01-18 20:45:47 EST > --- Thanks for responding to my first ever e-mail Kelly! --- The guy is new to this stuff. So could you wait a bit to jump on him? (We're trying to increase particapation!) He does not yet know the evils of the anti-christ Gates. ;) Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Fri Jan 19 17:01:41 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2744" "Fri" "19" "January" "1996" "10:53:01" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "53" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA21549 for ; Fri, 19 Jan 1996 08:52:02 -0800 (PST) Received: by maroon.tc.umn.edu; Fri, 19 Jan 96 10:53:03 -0600 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Kelly Starks x7066 MS 10-39 cc: Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com, kgstar@most.magec.com Subject: Re: Fwd: LIT e-mail discussion group Date: Fri, 19 Jan 1996 10:53:01 -0600 (CST) Kevin To Kelly Note, I'm using a different letter than the I'm replying to, because there are some new people on the cc list. Welcome! Kelly, you keep trying to compare apples to organges when you talk about repair vs. buying new. On the Repair side, you have materials, labor, expertise, and energy. You then try to say that these are much higher than buying new, otherwise groups on earth would be doing this right now. by saying this, you are comparing the cost of manufacturing a single specific high-tech gizmo with the cost of manufacturing a million specific high-tech gizmo's. That's not the same thing at all. Of course buying something new is cheaper, the economies of scale make sure of it. but in a limited system, repair would be balanced by the transport wieght of the spare. if it weighs 1 Kg, then it's going to take a whole lot of energy to boost it up to cruising speed (I still say C is possible, and I intend to prove it) and back down again. This is the cost which must be balanced against the cost of repairing an object. Some spares should be brought, and other things should be designed for easy repair. as for the amish. I say if there is trouble with the amish in your area, it is probably modern society which is in the wrong. There is a large Amish community near my hometown (Viroqua WI which I'm sure nobody ever heard of) and I have always found them to be peaceful people who only wish to be left alone. If modern society is encroaching, then it is not the amish's fault. Anyway, this is not the place for this discussion, my appologies. My point about the amish, is that by sticking to a particular point in developement (whether that point is 1840's, 1900's, 1940' or 2000's doesn't matter) one can significantly reduce the amount of "effort" needed to keep the society going. Add to that the fact that much of earth-bound technology is _deliberately_ inefficient, and I think we can get much better than a ten or one hundred fold reduction in personal. I think we could get that, just by standardizing the equipment, and roboticizing much of the routine jobs. I take execption with your statement that we can't endlessly recycle, the limits on recycling are not material, there are energy. Lint can be re-woven into socks, if you are willing to totally break down the plastic fibers and re-form them. Rust can be turned back into iron, you just need some electricity. I also think your warehouse vs farm numbers are off, as in your farm estimates, you are assumeing some kind of soil, and not taking into account hydroponics. without the soil, the weight goes down drastically, since the water can be re-cycled endlessly. Kevin in the frozen North From popserver Fri Jan 19 17:57:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6025" "Fri" "19" "January" "1996" "12:50:58" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "125" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA25752 for ; Fri, 19 Jan 1996 09:54:36 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA16313; Fri, 19 Jan 96 12:54:32 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016152; Fri Jan 19 12:52:35 1996 Received: by most (4.1/SMI-4.1) id AA06424; Fri, 19 Jan 96 12:52:32 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma006390; Fri Jan 19 12:51:00 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA08799; Fri, 19 Jan 96 12:50:56 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Re: Fwd: LIT e-mail discussion group Date: Fri, 19 Jan 1996 12:50:58 -0500 At 10:53 AM 1/19/96, Kevin C Houston wrote: >Kevin To Kelly > >Note, I'm using a different letter than the I'm replying to, because >there are some new people on the cc list. Good! >Welcome! > >Kelly, you keep trying to compare apples to organges when you talk about >repair vs. buying new. On the Repair side, you have materials, labor, >expertise, and energy. You then try to say that these are much higher >than buying new, otherwise groups on earth would be doing this right now. >by saying this, you are comparing the cost of manufacturing a single >specific high-tech gizmo with the cost of manufacturing a million >specific high-tech gizmo's. That's not the same thing at all. >Of course buying something new is cheaper, the economies of scale make >sure of it. but in a limited system, repair would be balanced by the >transport wieght of the spare. if it weighs 1 Kg, then it's going to >take a whole lot of energy to boost it up to cruising speed (I still say >C is possible, and I intend to prove it) and back down again. This is >the cost which must be balanced against the cost of repairing an object. >Some spares should be brought, and other things should be designed for >easy repair. Actually there is a three way split. Build, repair, carry spares. In our case the ship would need to be most concerned about mass. I.E. you might be able to make new I.C. chips, but the chips manufacturing equip would weigh more then a 40 year supply of circuts. Other things like exotic hard to manufacture alloys, composits, cermats, whatever, that the shuttles would need. Might require equipment too large to be carried along. Bottom line things will wear out. When it comes to the point that the frames, hulls, main power systems and such have reached their service lives. They are not practical to repair, they are scrap. Unless your proposing bringing all the equipment that every high end manufacturer uses. Sooner or later were going to run out of stuff. As the gear for things fails were going to have to give up doing things. Exploration and planetary landings would probably go first, but sooner or later even survival would be chancy. > >as for the amish. I say if there is trouble with the amish in your area, >it is probably modern society which is in the wrong. There is a large >Amish community near my hometown (Viroqua WI which I'm sure nobody ever >heard of) and I have always found them to be peaceful people who only >wish to be left alone. If modern society is encroaching, then it is not >the amish's fault. Anyway, this is not the place for this discussion, my >appologies. Yeah the bigges around here with the Amish are that they tend to chew up (and dirty) the roads with the horses, and they try to run resteranys that don't meet hygen standards. Also some problem with pollution since they don't want to upgrade sanitation and plumbing. >My point about the amish, is that by sticking to a particular point in >developement (whether that point is 1840's, 1900's, 1940' or 2000's >doesn't matter) one can significantly reduce the amount of "effort" >needed to keep the society going. Add to that the fact that much of >earth-bound technology is _deliberately_ inefficient, and I think we can >get much better than a ten or one hundred fold reduction in personal. I >think we could get that, just by standardizing the equipment, and >roboticizing much of the routine jobs. Judging from the fact they work harder at maintaining there lowtech comune life style then I do my high tech style, I'm not sure about your comparison. The military is probably a better example. They need rugged equipment, and keep it for decades with limited upgrades. But sooner or later it wears out and has to be thrown away. In a colony situation where your encountering new phenominon, your not going to be able to freeze yourself at some 'efficent' form forever. I totaly disagre with your assumption that a most social effort is senceles inovation for novelties sake. Thing have to be replaced routinly. MOst industries have to live with the fact of market saturation. >I take execption with your statement that we can't endlessly recycle, the >limits on recycling are not material, there are energy. Lint can be >re-woven into socks, if you are willing to totally break down the plastic >fibers and re-form them. Rust can be turned back into iron, you just >need some electricity. In theory thats true. Reality doesn't live there. The limits are practicality. You could break everything down to basic chemicals, ion separate them to acceptable prurity, and mine that like ore. But what sence would that make? Could you afford to bring along all that equiment? Even if you could what advantage would it give you? >I also think your warehouse vs farm numbers are off, as in your farm >estimates, you are assumeing some kind of soil, and not taking into >account hydroponics. without the soil, the weight goes down drastically, >since the water can be re-cycled endlessly. > >Kevin in the frozen North The weight estimates were from the old stanford study. which used mixed soil and hydro farming. (Hydro isn't that light, I mean water is heavy too.) The big kicker was the weight of the habitation area needed for the farm gear. That would roughly double the internal volume needed. It gets especially bad if you need to shield it. The book is on line now at http://www.nas.nasa.gov/NAS/SpaceSettlement/75SummerStudy/Table_of_Contents1 ..html Oh, NASA giving up on hydroponics to. Seems the maintenence and relyability are bad for exploration systems. Light soil based is now considered more promising. I'll reserve judgment. Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Fri Jan 19 18:42:50 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3806" "Fri" "19" "January" "1996" "19:40:25" "+0100" "Zenon Kulpa" "zkulpa@lksu.ippt.gov.pl" nil "93" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: zkulpa@lksu.ippt.gov.pl Received: from sunic.sunet.se (sunic.sunet.se [192.36.125.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA29123 for ; Fri, 19 Jan 1996 10:38:07 -0800 (PST) Received: from lksu.ippt.gov.pl by sunic.sunet.se (8.6.8/2.03) id TAA03120; Fri, 19 Jan 1996 19:39:16 +0100 Received: from zmit1.ippt.gov.pl by lksu.ippt.gov.pl (4.1/SMI-4.1) id AA01736; Fri, 19 Jan 96 19:40:25 +0100 Organization: Institute of Fundamental Technological Research Address: Swietokrzyska 21, 00-049 Warszawa, POLAND Message-Id: <9601191840.AA01736@lksu.ippt.gov.pl> From: zkulpa@lksu.ippt.gov.pl (Zenon Kulpa) To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, RUSSESS@cellpro.cellpro.com, jim@bogie2.bio.purdue.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, KellySt@aol.com Cc: zkulpa@sunet.se Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 96 19:40:25 +0100 > From KellySt@aol.com Fri Jan 19 05:51:43 1996 > [...] > You seem to be arguing my point. You are proposing to be the mission > control/cameraman eager to send crews out to die on the frountier for fame > and fortune. > No! > > [Zenon:] > > Political organizations (and opinions) are not laws of nature, > > but emanations of people's opinions and attitudes. > > If they (the people) have such attitudes as you seem to propagate > > in our discussion, that it's not surprising that they possibly > > will not "support or allow" ANY flight (that's risky, you know - > > untested technology, not complying to these mountains of government > > rules and regulations of safety, no guarantee of safe return, > > high probability of accidental loss of life, > > probably far larger than in Kuwait...). > > So, if we want to go to the stars at all, > > we must fight off such attitudes. > > Not to say of other resons to do so. > > Why fight off such an attitude? Your proposing throwing away a crew like > they were expendable parts. All for the convenence of a flashy, but non > crytical, program. > No! > Linbergh had a comercial ship customized for his purposes and had every > intention of geting there alive. He got sponcership because everyone was > fairly sure he wasn't a suicvidal ameture who would take stupid unnessisary > risks. > No. Anyway, do I propose "taking stupid unnecessary risks" when I say that I would rather stay back at the base than risk the return flight to Earth? > Comes the time we blithly throw away a few hundred people to save ourselves a > little time and trouble, for a cause of no urgent critical importance, > humankind doesn't deserve. > > As you may remember I was working in NASA shuttle flight planing when the > Chalenger (almost exactly ten years ago) ripped itself apart in mid air. > Largely because some political types desided not making waves and bad PR was > more important than a few astronauts lives. After that a lot of political > types got fired and a lot of astronauts quit. NASA had violated a cardinal > rule of test pilots. They'ld risk their lives if it was important enough, > but the people on the ground had to keep them informed and do everything > possible to keep them alive. > No! Do I propose NOT TO INFORM the crew that they are going to stay there at the outpost for all their lives? Do I propose NOT TO DO EVERYTHING POSSIBLE to keep them alive there till the (natural) end of their lives? > Doing a cost benifit analysis and deciding > their lives arn't cost effective, doesn't cut it. > > I don't know what kamakazis you could get for such a flight, but they'ld be > the dregs of this race, and I'ld be assamed for them to be my representatives > to the stars. > Kamikazis??? Dregs??? Come on, Kelly, don't try to offend me! It will fail: I am an 'ceptionally calm & stubborn kind of guy... ;-)) Anyway, my keyboard becomes jammed and fingers aching with this discussion - seemingly I am somehow basically unable to understand your position, and you are not willing to understand mine, so let us drop it for now. However, I insist that the two discussed types of mission ARE an option, however improbable from your standpoint, as there are many others willing to go on such a mission and ready to fight their way to it with all these "guardian angels" [that's you, Kelly :-)) ] thinking they know better what is good to others... So be it, -- Zenon P.S. Anyway, the "Design Space" listing I propose for our status report can, and should, contain also (some) options considered by (most of) us as improbabale or impossible, just to delineate BOUNDARIES of the design space... [except possibly such totally silly ideas like driving the ship with steam engine]. -- Zenon From popserver Fri Jan 19 19:04:38 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6278" "Fri" "19" "January" "1996" "20:00:28" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "146" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA01226 for ; Fri, 19 Jan 1996 10:59:22 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA09442 (5.67b/IDA-1.5 for ); Fri, 19 Jan 1996 20:00:23 +0100 Message-Id: <199601191900.AA09442@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 20:00:28 +0100 Timothy replies to Kevin: >> Reading the kind of English that you guys write is not too difficult so I >> can almost always manage without any help. > >I'm not sure if that is a compliment or a put-down ;) I'm not sure either :) >> Yes a radius of 580 kilometre, but would it not become too hot? (the >> radiation level is about 10000 Watt/m^2) > >I think the heat could be kept below the melting point of silicon. As >the Temperature goes up, so does the blackbody radiation. But since the doped silicon is quite temperature sensative 100 degrees extra may have a bigger effect than you would expect. >> >> That would always be anti-matter or a beam that is very tight. >> > >> >i don't agree, that's true only if you want to do it in a man's >> >lifetime. if you are willing to accept a lower speed, then you can do >> >the trip with a _lot_ less energy. >> >> The the answer is also easy, with one Joule you could come everywhere. (live >> support not included ;) ) > > >That reminds me of a great new travel method making use of Hiesenberg >Uncertainty principle: as Temperature approaches Abs Zero, Momentum >becomes zero to the last decimal, and the position becomes _infinite_. It is not the position that becomes infinite but the PROBABILITY of its position that becomes infinite. May look the same, but is different. The chance to find the particle at a particular place in the universe will be almost zero, but the chance to find it in space as a total stays equal to one. So effectively you won't know where your particle is after you cooled it down to absolute zero. The fact that a particle can move lightyears be everywhere is As you can see, this Although this may look as if it is conflict with the finite speed of light there is a deeper understanding that solves this "paradox". >the recent cooling of some atoms down to nanokelvins of Abs Zero, makes >me hopeful that this might someday work. although how you go from room >temp to even a "balmy" -40 (celsius, Farenhiet, what's the diff. ;) ) >is another question, but if you could make to that emp and survive, then >perhaps you could make it to Abs Zero. If it can be reached, than it's unlikely tha >Solid yes. Metal, no. at one atm, hydrogen becomes an ice-like solid, >which does not have any free electrons. only at great pressures >(ie Jovian core) does the hydrogen take on any metallic properties. I didn't know that, do you know a subject or book about that, where I can search for in a library? >> Yes, I proposed that idea some weeks ago. > >Oops, musta missed that one. It was in the long and dreary letters I wrote Kelly ;) >one robot may not be able to replicate in three days, with out some >minimum number of "support" units, to mine ore, cart raw materials to >easy places etc etc OK. >> (Note: Probably all robots will be worn out after a few years, so you may >> need 3 or 4 times more than you originally would think, that would only cost >> a few days extra) > >Any robot could probably repaired far cheaper than it could be re-built >from scratch, and this could be done at any time, not just at the outset Repairing is rather difficult, for some dumb replicating machine it is probably much easier to make a new one than to look for the non-working part and replace it. It is just like a conveyer belt, there is a gain because of the repetative task. >i think TCP/IP would be much better suited to robotic units than to humans 1E13 adresses need about 42 bits that's 10 bits more than the current URL/IP needs :) >This is where you have some robots dedicated to the task of routing. if >each robot has a long-range low-bandwidth transmitter (to call for help, >or report on distant conditions) and a high-bandwidth short-range (10m?) >transmitter, then there should not be too much radio interferance. As >for physically bumping into each other, one robot in 1024 could be >dedicated (aside from it's router duties) the task of "traffic control", >telling two robots when they get too close to each other (say within two >meters) I hadn't thought of the short and long range possibility, that would be a good solution. >in thinking about this, i was struck by the comment you made about the >radius of the solar collector being about the same as the face of the >moon, and i thought, what if instead of putting it (the collector) in >orbit around the sun at Mercury's distance, why not just cover the >surface of mercury with solar panels? (not too difficult if you have >self-replicating robots) They could exist underground safely, and the >maser array could be placed on the south pole of mercury (TC is below the >ecliptic) Mercury would provide more than enough counter-weight for the >beam, and the low gravity would assist the robots in maintaining the arrays Yes, that would also solve the problem of the solar-panels and laser-array being blow away by the photon pressure. A problem still present, is that the laser-array has to be directed, wich may be a problem on a rotating planet. >> Computer circuits mostly need semi-conductors, so I think super-conductors > >Ever hear of a Josephson junction? Yes, but as far as I know a Josepson junction has nothing to do with transistor like properties. (Or am I mistaken?) (What does mean?) >> may not work there. But the other applications may be useful. Oh by the way, >> super conductors can't conduct infinite currents... I don't know what their >> maximum is though, I asked someone who worked with them but he didn't know >> either, they used only small currents and small pieces. > >yes, i knew that, but that may be a limitation of technology, or is it >fundamental? It is fundamental, it is limited by the paramagnetic energy of the electrons. If too many electrons are moving, the special conditions are distroyed and superconduction is lost. I looked through some books and found that the maximum magnetic field possible for a certain superconductor with Tc=20K was 36 Tesla (Probably enough) But I still don't know the maximum current. The field would be have the same value at 1 cm distance from the center of a wire that conducts 350 Ampere. (rough approximation). >Keivn Is that your name in phonetic language? :) Timothy From popserver Fri Jan 19 19:04:43 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2983" "Fri" "19" "January" "1996" "20:00:43" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "70" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA01254 for ; Fri, 19 Jan 1996 10:59:34 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA09474 (5.67b/IDA-1.5 for ); Fri, 19 Jan 1996 20:00:38 +0100 Message-Id: <199601191900.AA09474@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com Subject: Re: Engineering Newsletter Date: Fri, 19 Jan 1996 20:00:43 +0100 To Ric: >Can we design a ship to take 1000, 2500 people? Yes, ship-fuel ratio is the thing that is most important. But of course, the weight of the ship does not influence that ratio. >Can we insure we can have the proper and correct amounts of food and spare >parts? That is were we are discussion about at the moment, so keep an eye on to the newsletters for the final answer. >Can we drive, ( stear ), the danmed thing? Probably yes, otherwise it would mean that it would explode because of shear-forces that were not accounted for. But you should have in mind that you CANNOT make a turn whenever you like. If you travel at 100 million mph you need a very long way (probably lightyears) to make a 45 degree turn. >Can we stop it once we get it going? Yes, but we haven't found an easy reliable method unless we are using anti-matter or fusion (both are bad for different reasons) >Can we get it started at all? Same answer as before, although the options are broader: beaming and (prelaunching?) The trouble is that ALL methods need enormous amounts of energy and to make it worse most aren't even near efficient. So if we had an easy way to releasu this energy and an easy way to carry it then it would not be a problem. Oh yeah, there is still another problem, time. The period of 20 to 40 years makes all problems even much harder, things just can't be build so fast with so few people. >The big problem as I see it is building a drive to get us to TC and back if >we want to. The rest we can probably do with the technology we have today or >in the next ten years. Don't say that, a 600 meter tube of ten metres in diameter with shielding is quite large and then you only have a habitat. You still need the rest of the ship and an engine (which method is used is not so important here) which will probably weight more than the habitat ring. Than you have to build a large array of solar-pannels and laser-arrays or you have to accumulate 1E11 kg of hydrogen (assuming fusion). I think that such a task is still to much in 10 years time. >I know I know Nothing about the physics of all this that many of you are >writing about. But I do know we are running in circles right now. How do we >proceed? I don't have a clue. Just give me a hammer and some nail and I will >start building the ship :-) You guys come up with the steam engin to push >it. You can already start building the hab-ring, by the time you are finished we will have a design for the engine :) >Maybe we need to concider several types of propulsion. kind of like a >small sailboat that has sails, outboard motor and oars. Or just build the >thing large enough to carry all the rocks we will need to toss into the >ramscoop. Or, maybe we just might have to set our sights closer to home. Some long time ago we decided that it would not have an advantage to use multiple systems. The differences between all methods are so big that one or another will always be much more feasable. Timothy From popserver Fri Jan 19 23:13:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["753" "Fri" "19" "January" "1996" "23:56:22" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "19" "" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id OAA19054 for ; Fri, 19 Jan 1996 14:55:04 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA25098 (5.67b/IDA-1.5 for ); Fri, 19 Jan 1996 23:56:15 +0100 Message-Id: <199601192256.AA25098@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Date: Fri, 19 Jan 1996 23:56:22 +0100 To Kelly: > One of the Good things about places like Biosphere II is not what we will > learn about closed-sytem ecologies (which will be argued no doubt), but > what they teach us about our consumer society. What we learn to do > without and what we find indispensible Did you ever lok at all the high tech, high maintenence gear it took to keep Bio-shpere going? Oh, and it wasn't enough! Kelly do you know why there was too little oxigen? I've never heard the real reason for it, some thought the oxigen had oxidated with the metal inside the construction. I think that the glass may have filtered out some essential radiation or it may have dimmed the light too much. Timothy P.S. You guys shouldn't write so fast, I can't keep up... ;) From popserver Sat Jan 20 17:00:49 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1704" "Sat" "20" "January" "1996" "11:05:25" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "40" "" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id CAA23193 for ; Sat, 20 Jan 1996 02:04:01 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA22604 (5.67b/IDA-1.5 for ); Sat, 20 Jan 1996 11:05:20 +0100 Message-Id: <199601201005.AA22604@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Date: Sat, 20 Jan 1996 11:05:25 +0100 To Kelly and Zenon, This is a NASA-newsletter that I got yesterday, it neatly reflects (y)our discussion which is going on. (I've added the > for the most important part) ADMINISTRATOR GOLDIN ISSUES STATEMENT ON CHALLENGER OBSERVANCE NOTE: The following statement by NASA Administrator Daniel S. Goldin was released today in observance of the upcoming 10th anniversary of the Challenger accident. "The best way to honor the memories of the crew of the Challenger, and of all the men and women who have given their lives to explore the frontiers of air and space, is to continue their bold tradition of exploration and innovation. That's what the people of NASA do every day. They push the boundaries of knowledge and human endeavor to improve and enrich life on Earth today and secure a better future for all of us tomorrow. > "I've said many times that safety is the highest > priority at today's NASA. We will not waver from that > commitment. But human beings have always taken great risks > to reap great rewards. Space flight is inherently dangerous > and every member of the NASA team understands those risks. "I'm proud of the women and men of NASA. They're blazing the trail to the future. They're building the components of the International Space Station. They're constructing spacecraft that will explore the farthest regions of the Solar System and the universe, and satellites that will monitor the health of our own blue planet for years to come. They're conducting cutting edge research that will make airplanes faster and safer, and they've made the Space Shuttle the most capable, reliable and versatile spacecraft in the world." From popserver Sat Jan 20 17:01:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10510" "Sat" "20" "January" "1996" "15:14:43" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "219" "To Brian" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA27893 for ; Sat, 20 Jan 1996 06:13:28 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05177 (5.67b/IDA-1.5 for ); Sat, 20 Jan 1996 15:14:37 +0100 Message-Id: <199601201414.AA05177@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: To Brian Date: Sat, 20 Jan 1996 15:14:43 +0100 Hi Brian, My name is Timothy sometimes its Tim, whatever I feel like. If you like to read some info about me look at my humble internet-site: http://www.cpedu.rug.nl/~N0642983/personal.html I have the habit to comment a lot and write less myself, simply because it is hard to figure out some well working idea. Others often try but fail after a while (not always ;) ) By the way Steve and I have an official nickname: "reknown throwers of icewater" Kevin, how is you snowball ship doing? >What does Cc mean anyway? Carbon Copy it's derived from the good old days where they didn't have E-mail and Xerox-machines. >Thanks for responding to my first ever e-mail Kelly! For the group's >information, I'm a junior pre-med biochemistry major at Oklahoma Christian >University of Science and Arts (it's a long name, I know) who hates the math >aspect of most anything but has seen too many Star Trek and Babylon 5 >episodes to not be interested in LIT's starship design project. Hmmm, you don't like math, then try not to read :) http://www.cpedu.rug.nl/~N0642983/calc.txt >If this system involves power beaming, then there are going to be some >serious losses in energy during the transfer. Why would there be serious losses? It is a non diverging PARALLEL beam! >HERE COMES ASCII ART :-) It really looks like garbage, are you using a proportional spaced font? If so try using a fixed sized font... I haven't been able to get it ungarbled... >I'm posting a BMP file of this idea right here just to see if it works. >Should be easier on the readers' sanity as I've heard complaints about this >somewhat limited artform. How's the color? The colour is fine, but never sent a 400kb bmp file again. ;) (My mail-deamon complained that it took too long, so I could start over again) The small mirror should not be concave (hollow) but convex (spherical) ! >Unfortunately, some power would be lost as it hit the secondary mirror (we >could make it one-way transparant if it were glass-like) and there will >certainly be losses due to irregularities in the mirror's surface and the >reflective material (silver is the best I can think of and that ain't >cheap). The two would have to be connected as well to prevent any net >movement. We are talking about micro waves, not visible light, so comparing with ordinary mirrors and lenses has no use. >Zubrin suggested that the particle stream be >neutral on the way to the magsail and that a laser carried on board could be >used to ionize it. I would suggest using a laser that was NOT on board >because, as someone pointed out in ARC29, it would take a terawatt to ionize >100 sq. meters, not accounting for conversion efficiencies of energy into a >photon beam. Why not use the beam alone instead of first beaming particles and then a maser beam to ionize them. Also tapping the magnetic field would probably have a very bad efficiency. >I know that I am jumping from topic to topic here. Its just that I've got a >lot on my mind that I want to get to you guys before I have to face my >Calculus homework. By the way, you may be wondering where we are getting >the power for these propulsion designs. No, we aren't wondering any more... We have given up hope, after going through all possibilities. >From the billions of 10 kilometer >square power stations out between Mercury and Venus, of course. Indeed, about 1E12 m^2 or a billion 1 square kilomtres. What you probably haven't thought of is that the same solar-radiation they capture also pushes them away. And it is not neglectable! (It is bigger than the momentum our spaceship has after accelerating) There have been some ideas to overcome this problem, but they don't make it easier. >Switching gears here, I was going over some information on the Deadalus >probe in a book called "Bound for the Stars" by S.J. and B. Adleman. > Anyway, the book said that the design was supposed to have a 15 to 1 fuel >to ship ratio that would get a 500 ton payload to just over .10c. Using >that as the working number to beat, and knowing that the probe uses greater >than twenty-thousand tons of 3He (not exactly a common isotope), I tried >figure out how we could make that monster more fuel efficient. The ideal >scheme would be to launch the fuel from Sol to the ship. Or better yet, to >launch the ship to the fuel that is already on route. Better still, >perhaps, do both. Actually the ratio could be a lot better say 1:4 although no-one has confirmed my number yet. By the way we like using the scientific exponential notation: 10 tons = 1E4 kg This is because sometimes the use of million and billion is not completely clear and it makes comparing easier also. 5E5 kg is too little, we are talking about 2E9 kg or so, maybe a bit less but I think that 1E7 kg is the absolute minimum. >Anyway, the first tanker will actually have to carry enough fuel >to slow the ship as much as .1c, but thems is the breaks (I actually made a >semi-descent pun without meaning to). This first tanker will also be >traveling only as fast as it can slow the starship to a full stop at the >next gas station in Tau Ceti's Kupier belt. > >The other smaller tankers will be launched during the appropriate windows >that will let them reach a position along the flight path that allow a >starship to catch up with them, find them in deep space via the homing >beacons, dock with them, and finally use their fuel to slow to the speed of >the next tanker and repeat the process. This means that the overall >deceleration phase will be fairly lengthy. Ha, this was my idea, we discussed it and guess what, it is discarded for two reasons: - To get the slowest tank at TC would take at least 100 years, too long for any project. - The time and place precision needed by the decel-track would not be feasable. >By the way, the whole shielding problem is still of some concern to me. How >much do we really need when flying at relatavistic speeds? I think that we >should should pray to God that he doesn't put a lot of little paint flecks >sized particles between us and the stars or else our ship will run into them >and they will cause dents way bigger than seen on the space shuttle window. > One of "Bound for the Stars" suggestions for protection against smaller >debris was to put a dust cloud/bag of some sort ahead of the ship. It would >act like a forward atmospheric shield. I'm of the opinion that a solid shield is better than a gassious one. Simply because it stays where it is and doesn't involve elaborate ice-gas shooting cannons. It has been suggested to use a simple ice shield (not necessary water-ice), it could be more easely renewed and may work well. >Back to weight efficiency in the ship's design. If the magsail is big >enough to effect any sort of deceleration by using the interstellar ionized >gas, then we should turn the ship around. To do it, we fold the sail like >an umbrella, turn, and redeploy it. Ionize interstellar gas, you are talking about it as if you could see it, the best guesses are that the there is too few interstellar dust. Only a ramscoop with a 1000 km radius may be enough to make some significant use of it. I still have a hard time imagining how a magsail could work efficient, magnetic fields have the peculiarity to be not very bundled. >Whatever kind of deceleration it >produces will probably go virtually unnoticed by the crew and may be >compensated for in how we rotate our habitat for artificial gravity and or >by how it is laid out internally. Exactly how we want to produce >artificial gravity will be determined in a later discusion. We use engine thrust and centrifugal forces for gravity, there are no other known possibilities. >The only viable >solution that I can come up with to keep the shielding costs from getting >too far out of control is to use fuel/reaction mass as shielding. Also we >could send some fuel/reaction mass/shielding after the ship. This would >require putting an extra engine on either the fed express tanker or the >starship. The problem with using fuel/reaction mass as shielding is that you have to carry that fuel, if you want to get over a minimum speed of 0.3 c it is impossible to push the fuel. >For the cruising phase of the flight, we can afford to make a habitat that >is spacous and comfortable. As soon as we want to slow down, however, we'll >have to stuff the crew into a collection of cramped, space economized, >modularized, trailer car-like habitats that fit into the cargo bay of the >space shuttles that we'll use to explore planet surfaces. Too bad, we will be accelerating and decelerting all the time, so there is no cruising phase period. And why would you make the ship bigger than needed, acceleration takes energy too you know. >This deceleration >storm shelter complex will be much easier to shield and, after we jetison >(how do you spell that word?) the cruising hab, will drop the ship weight by >tens if not hundreds of thousands of precious tons because the fuel that was >formerly shielding for our interstellar space hotel will then be used to >slow the ship to reach the first tanker drone. (Wow a sentence of five lines with two commas) After having thrown away the biggest part of your ship, how are you going to return? >You've probably noticed that I don't hold out much hope for getting our crew >back to Sol in their life-times. Over the last few days I've come up with a >mission plan called for a starship named U.S.S. LEGACY. It is to be the >pioneering manned starship of a colonization effort. Other ships like the >U.S.S. HERITAGE will follow but that's my little fantasy. For now I'll play >with the ASIMOV. Ah thats why you throw away your ship. Makes me wonder how you want to camp in the TC-system. Maybe you should have a long talk with Kelly... By the way you have the name spelled wrong, it should be E.S. LEGACY it is a European efford you know. ;) >It is late and I need to do Calc. I imagine that someone has come upon >these ideas long before me but I hope that what I've written has helped to >refocus some thoughts (II Peter 1:13 I think it is right to refresh your >memory as long as I live in the tent of this body). Thanks for taking the >time to read This, My Core Dump. I not only read it, but even commented it... >I invite comments to be sent by bus, plane, train, automobile, phone, mail >or e-mail. Don't you have a fax? :) Timothy From popserver Sat Jan 20 17:01:21 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9029" "Sat" "20" "January" "1996" "15:14:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "179" "To Kelly" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA27899 for ; Sat, 20 Jan 1996 06:13:38 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05197 (5.67b/IDA-1.5 for ); Sat, 20 Jan 1996 15:14:54 +0100 Message-Id: <199601201414.AA05197@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: To Kelly Date: Sat, 20 Jan 1996 15:14:58 +0100 Tim replies to Kelly: >> OK, but we don't need much manufacturing after the initial build up. It >> takes much less effort to keep what you have than to build something from >> scratch. >> Also a big amount of the 95% spend on manufacturing are the cost for raw >> materials, I expect the cost of mining raw materials will be less at TC >> because we can pick the easiest sites. No deep-sea oil drilling, most ores >> we need will be somewhere near the surface. > >Raw materials will be in space. MOst of the best ore beds on earth are >crashed asteroids. We can go to the source! Yes, that's what I meant, so that means a saving of say 80% with respect to the raw materials. Thus we have 5% spent on R&D and 15% spent on other man-power. >Its not allways easier to maintain an established thing then to build a new >thing to replace it. Often its much more expensive to maintain the old thing >then replace it. Thats especially true of light high performance things like >space ships, trucks, and cars. We could be a bit more effocent then people >are here on earth, but not dramatically so. If we could, people would do >that here to save money. Actually since we'ld be doing things in small >coustom bunches, not large mass production lots like back here on earth. > We'll be far less efficent in T.C. space. People do buy new things because they can faster earn the money for a new object than repair it themselves or take the trouble and time to get it repaired. >> I still don't see why it is not possible to scale things down. If you need >> 1 million people to feed 3 million people why can't you do with 100 workers >> for 300 people? > >Actually it takes a couple dozen people to feed 3 million people. But to >maintain a socyiety it takes millions of differnt professions. You cant >train 100 people, to each do 60,000 professions and do them well. And we >arn't in a good position to deal with a lot of sloppy workmanship. I hoped you would take the word feed not literally... Anyway a lot of these professions are sub-divisions of other ones, how many "professions" are taught at universities and schools? All economic, administrative, trade and a lot of social professions won't be needed that bad in a small independant colony. You said yourself that the bigger the group, the more coordination is needed. >>>Later in this letter you mentioned this idea again and suggested if systems >>>were designed to be maintained they would require less replacement. To a >>>degree true. But after a couple decades everthing wears out; and the reason >>>we got used to throwing away things rather than repairing them, is its >>>cheaper and takes less effort. >> >> Yes, but in those decades you would need much less new materials meaning a >> lot less work. The cheaper-throwing-away habit will not work on TC because >> it will take more effort to build a completely new object than to replace a >> single part. The reason that I mentioned this was not to say that things >> wouldn't wear out, but that the amount of work needed would be less since >> not all parts of the object have to be replaced each time. > >Why do you say, a few decades? What would change after 30 or 70 years? Are >you expecting better ships or something? No, you misunderstood, I meant the time that the objects would last. Of course there isn't really a duration that an object lasts because it has had many repairs, but I meant that time was equal to the breakdowntime of the last part. So by the time all parts have been replaced once or more times, you should add up the work for building say 100 new sets each having 100 parts OR replacing and making 1000 new parts. ============================================================================ >No the fuel is still multiplied by tweenty. Thats the whole point. OK, I think I see what you mean. >Earth got life very quickly after it cooled. Mars may have life. Then their >is Venus whose crust is wrong which makes it to hoot. What does that give >you for odds? And is it an average sample? Given the extreams of >temperature, radiation, chemistry, etc.. that life lives in on earth. > (icewater, nuclear reactor cores, water hundreds of centigrade above 0, >deserts) I'ld expect to find life almost anywhere. What kind of live lives around nuclear reactor cores? I've heard that some old corpses were not decomposed because they were burried in a cave where the radiaton level was so high that even the decomposing bacteria couldn't live there. Mars may have life but if we won't check it we can't be sure, so lets launch a simple rocked, that takes some samples and analizes them for some traces of life. >Venuses temp is NOT due to its atmosphere. Its due to its crust, its a >fraction of the thickness of earth crust and doesn't insulate well enough to >keep the surface cool. So after the venus cools down slowly, the crust will get thicker and it may become like Earth? >You can get just as dead in liquid air as in liquid metal. Eiather way your >pushing equipment hard, and without a good survival odds when it fails. I wasn't assuming a planet with an liquid metal atmosphere. By the way it would be hard to build something there. >> I'm not sure, would recycling not have a bigger influence on reducing the >> need for raw materials? Taking all the rubbish down means that the rubbish >> on Earth would increase, and we already have to much of that. > >For ecology purposes moving heavy industry off planet would do more than >anything else to ease ecology strain. Of course their are international >political and cultural problems with that (proably a couple of wars with the >third world). Heavy industry on Earth is so dirty because it uses a lot of energy and doesn't take enough care about its side-products. When fusion becomes normal, energy is very clean. And in space you can't just leave all the dust flying around either. >Stuff can't be recycled forever. After a while it just doesn't make any >sence. Right now we in the (throw it all away) U.S. have litle real problem >with waste disposal (though an incredible amount of political problems). > about 80%-90% of our garbage is paper and similar compustables. The small >fraction of metals and plastics %5ish, can be broken down or shiped into >space if you crazy enough. Besides if the industry moves off planet to get >to the resources, the materials to be recycled would need to be shiped up to >be recycled anyway. Shipping up takes large amounts of energy, that means an environmental problem unless you use fusion power. >No I ment no food raiseing. Oh, you can have a couple of tomato plants in >your apartment for recretion. But farm systems weigh too much if your only >going out for a couple of decades.. But why did you speak about veggies(10 tomatos a year?), bread/pasta(corn), meat/chickens(need food=plants too)? >I know ther are dozens of differnt anti-biotics each tailored to various >things (and most becoming ineffective), but I don't know much more than that. You are talking about the small-spectre anti-biotics. The ineffectiveness is caused mainly by the not finishing the cure and thus allowing the bacteria to become resistant. Broad spectre are useful if a bacteria with a lot of different brothers and sisters is active. Broad specre anti-biotics kill several different bacteria. > Why would you think we could fight them? Because I think we are smart and that since life is universal it will be like the organisms we know because the set of chemical reactions that can support life is very limited. In fact if there is alien intelligent live (which is no doubt about) they will have hands like we do (a finger more or less) just because that is necessary to get intelligent. (intelligence without a need means nothing to Darwin) So they won't have claws or hoofs or fins because these don't need a big brain to use. They also will have some light sensative organs (otherwise a even small brain isn't needed). They will need touch and taste/smell senses. So that makes them already a lot like the organisms we know. So, the don't walk on all limbs otherwise the hands cannot get sophisticated enough. That makes that they are standing up if the have 4 limbs. If they have more limbs. More limbs is not very efficient for larger organisms that have to carry a brain of 1 kg. So they have a brain, would it be like we know it or are there some radical different possibilities, I don't think there are, as I said before there is a very limited set of chemical reactions that can be used. So they have a large brain similar to ours, and need a lot of oxigen to keep it working. So they have one or 2 longs and hearts. They need to feed themselfs, so they have teeth. They are probably omnivores, planteaters need to much time eating, so haven't time to do something else. Carnivores need all their legs to catch their prey. OK why not reptiles? They are half coldblooded and can't really function without some external heat. Timothy From popserver Sat Jan 20 17:01:25 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1327" "Sat" "20" "January" "1996" "15:15:09" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "28" "To Kevin" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA27904 for ; Sat, 20 Jan 1996 06:13:41 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05205 (5.67b/IDA-1.5 for ); Sat, 20 Jan 1996 15:15:04 +0100 Message-Id: <199601201415.AA05205@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: To Kevin Date: Sat, 20 Jan 1996 15:15:09 +0100 Tim replies to Kevin: >My point about the amish, is that by sticking to a particular point in >developement (whether that point is 1840's, 1900's, 1940' or 2000's >doesn't matter) one can significantly reduce the amount of "effort" >needed to keep the society going. Add to that the fact that much of >earth-bound technology is _deliberately_ inefficient, and I think we can >get much better than a ten or one hundred fold reduction in personal. I >think we could get that, just by standardizing the equipment, and >roboticizing much of the routine jobs. Indeed, a lot of extra work is done because of all different brands that want to make their product just that much different that is impossible to use each others parts. On TC we won't make 20 sorts of beer or wine (Just an example, I'm not suggesting that a brewery is build). All members of the crew have to give up some of their personal preferences. >I also think your warehouse vs farm numbers are off, as in your farm >estimates, you are assumeing some kind of soil, and not taking into >account hydroponics. without the soil, the weight goes down drastically, >since the water can be re-cycled endlessly. >Kevin in the frozen North Yes, what from what I hear on the news, you have to create a selfsufficient community if you want to survive. Tim From popserver Sat Jan 20 17:01:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2871" "Sat" "20" "January" "1996" "15:15:13" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "65" "To Kevin and Kelly" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA27914 for ; Sat, 20 Jan 1996 06:13:53 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05211 (5.67b/IDA-1.5 for ); Sat, 20 Jan 1996 15:15:08 +0100 Message-Id: <199601201415.AA05211@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: To Kevin and Kelly Date: Sat, 20 Jan 1996 15:15:13 +0100 >Actually there is a three way split. Build, repair, carry spares. In our >case the ship would need to be most concerned about mass. I.E. you might >be able to make new I.C. chips, but the chips manufacturing equip would >weigh more then a 40 year supply of circuts. Other things like exotic hard >to manufacture alloys, composits, cermats, whatever, that the shuttles >would need. Might require equipment too large to be carried along. If we use self reproducing robots, a chip-backery should be on board anyway. >Bottom line things will wear out. When it comes to the point that the >frames, hulls, main power systems and such have reached their service >lives. They are not practical to repair, they are scrap. You can remelt the metal and make new plates. >Unless your >proposing bringing all the equipment that every high end manufacturer uses. Yes, but how much equipment are we talking about, we need machines for: - Metal treatment - Plastic treatment - Semiconductor treatment - Glas treatment >Judging from the fact they work harder at maintaining there lowtech comune >life style then I do my high tech style, I'm not sure about your >comparison. Using this analogy, won't the futere bring us a complete automatic world, where no one needs to work? >The military is probably a better example. They need rugged equipment, and >keep it for decades with limited upgrades. But sooner or later it wears >out and has to be thrown away. Yes, but then you have had more than enough time to build a replacement. >I totaly disagre with your assumption that a most social effort is senceles >inovation for novelties sake. Thing have to be replaced routinly. MOst >industries have to live with the fact of market saturation. A lot of computers are not being replaced because they completely don't work any more but just because the competion has faster ones. Indeed this is not true for all objects, like chairs etc. But if the chair is made of steel and plastic, it is unlikely that the whole chair has to be replaced at once. Maybe a leg will break of, but can be welded again. The plastic seat may tear but can be easely replaced. >In theory thats true. Reality doesn't live there. The limits are >practicality. You could break everything down to basic chemicals, ion >separate them to acceptable prurity, and mine that like ore. But what >sence would that make? Could you afford to bring along all that equiment? >Even if you could what advantage would it give you? Isn't it possible to make objects with unmixed materials, so that the recycle-ability is enlarged much more, long enough to last the lives of the crew. >The weight estimates were from the old stanford study. which used mixed >soil and hydro farming. (Hydro isn't that light, I mean water is heavy >too.) That water you need always, even if you use frozen food. Timothy From popserver Sat Jan 20 19:29:29 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5300" "Sat" "20" "January" "1996" "13:06:26" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "117" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA10332 for ; Sat, 20 Jan 1996 11:05:06 -0800 (PST) Received: by maroon.tc.umn.edu; Sat, 20 Jan 96 13:06:27 -0600 In-Reply-To: <199601191900.AA09442@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: Engineering Newsletter Date: Sat, 20 Jan 1996 13:06:26 -0600 (CST) On Fri, 19 Jan 1996, Timothy van der Linden wrote: > >I think the heat could be kept below the melting point of silicon. As > >the Temperature goes up, so does the blackbody radiation. > > But since the doped silicon is quite temperature sensative 100 degrees extra > may have a bigger effect than you would expect. I guess that I have more confidence in materials science advances, I think that a Photovoltaic material can be manufactured that will work in the high temp/high rad environment > > > > > >That reminds me of a great new travel method making use of Hiesenberg > >Uncertainty principle: as Temperature approaches Abs Zero, Momentum > >becomes zero to the last decimal, and the position becomes _infinite_. > > It is not the position that becomes infinite but the PROBABILITY of its > position that becomes infinite. May look the same, but is different. The Ah, yes, I see. I knew that, but must have forgotten it. so i guess it would work, you just would be able to steer. Oh well. Back to the drawing board. > The fact that a particle can move lightyears be everywhere is As you can > see, this Although this may look as if it is conflict with the finite speed > of light there is a deeper understanding that solves this "paradox". I'm sorry, I don't understand your language here. Can you please re-phrase, check your dictionary, or insert the word or words you may have dropped. > >Solid yes. Metal, no. at one atm, hydrogen becomes an ice-like solid, > >which does not have any free electrons. only at great pressures > >(ie Jovian core) does the hydrogen take on any metallic properties. > > I didn't know that, do you know a subject or book about that, where I can > search for in a library? Sorry no, it's part of the great storehouse of knowledge that i have come across in almost fifteen years of reading every science magazine I can get my hands on. i think this subject appeared in OMNI, someone somewhere was claiming to have put a _lot_ of pressure on a small sample of hydrogen and gotten it to a metal state. > >> (Note: Probably all robots will be worn out after a few years, so you may > >> need 3 or 4 times more than you originally would think, that would only cost > >> a few days extra) > > > >Any robot could probably repaired far cheaper than it could be re-built > >from scratch, and this could be done at any time, not just at the outset > > Repairing is rather difficult, for some dumb replicating machine it is > probably much easier to make a new one than to look for the non-working part > and replace it. It is just like a conveyer belt, there is a gain because of > the repetative task. OK, I see. but a small number of units could be devoted to the constant manufacture of robots (which would then go off and do other things) so that replacement units were always ready. > > >in thinking about this, i was struck by the comment you made about the > >radius of the solar collector being about the same as the face of the > >moon, and i thought, what if instead of putting it (the collector) in > >orbit around the sun at Mercury's distance, why not just cover the > >surface of mercury with solar panels? (not too difficult if you have > >self-replicating robots) They could exist underground safely, and the > >maser array could be placed on the south pole of mercury (TC is below the > >ecliptic) Mercury would provide more than enough counter-weight for the > >beam, and the low gravity would assist the robots in maintaining the arrays > > Yes, that would also solve the problem of the solar-panels and laser-array > being blow away by the photon pressure. A problem still present, is that the > laser-array has to be directed, wich may be a problem on a rotating planet. Perhaps not a problem at all, earth based telescopes track distant stars all the time. Being placed at a polar position would decrease the rotational velocity to be countered, and if the problem is insurmountable, then an orbiting waveguide can be used > > >> Computer circuits mostly need semi-conductors, so I think super-conductors > > > >Ever hear of a Josephson junction? > > Yes, but as far as I know a Josepson junction has nothing to do with > transistor like properties. (Or am I mistaken?) > > (What does mean?) means spelling uncertain. i think a Josepson junction is a tunneling transistor, and it only works in superconducting conditions, but don't ask me why, maybe steve knows. > It is fundamental, it is limited by the paramagnetic energy of the > electrons. If too many electrons are moving, the special conditions are > distroyed and superconduction is lost. I looked through some books and found > that the maximum magnetic field possible for a certain superconductor with > Tc=20K was 36 Tesla (Probably enough) But I still don't know the maximum > current. > > The field would be have the same value at 1 cm distance from the center of a > wire that conducts 350 Ampere. (rough approximation). 350 amps in a 1 cm wire ain't all that bad, but I know that the ceramic superconductors aren't nearly that good. > > >Keivn > > Is that your name in phonetic language? :) > Know, eye Think That Kell'ys Bad Speeling virus Has infected me. ;) Kevin From popserver Sun Jan 21 03:22:43 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4922" "Sat" "20" "January" "1996" "19:46:04" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "98" "Engineering newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA00383 for ; Sat, 20 Jan 1996 17:44:40 -0800 (PST) Received: by maroon.tc.umn.edu; Sat, 20 Jan 96 19:46:04 -0600 In-Reply-To: <199601201415.AA05211@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Engineering newsletter Date: Sat, 20 Jan 1996 19:46:04 -0600 (CST) > If we use self reproducing robots, a chip-backery should be on board anyway. No, each of the robots would be able to make chips on their own, the process isn't all that different than making solar cells. Of Course, if they can make the chips they need, then the ones we need should be no problem. > Kelly writes: > >Judging from the fact they work harder at maintaining there lowtech comune > >life style then I do my high tech style, I'm not sure about your > >comparison. But Kelly, the reason _you_ don't have to work so hard to maintain your life, is because many other people (millions and millions) have specialized and are suppling the things you need. since Most of the Amish do their own Work (ie they grow their own food, repair their own equipment) the analogy is not fair. > >The military is probably a better example. They need rugged equipment, and > >keep it for decades with limited upgrades. But sooner or later it wears > >out and has to be thrown away. Actually, The military is a lousy example, they too are specialized, and if they weren't training how to fight, they would have plenty of time to build and repair whatever they needed. > > >The weight estimates were from the old stanford study. which used mixed > >soil and hydro farming. (Hydro isn't that light, I mean water is heavy > >too.) > > That water you need always, even if you use frozen food. In fact, you would have less water in a hydroponics system than you would have in frozen food. Let me take the example of carrots (simply because i happen to have a seed packet right here "Royal Chantenay", length about 5-6 inches, width about 2.5 inches) Assuming a crew of 1024, each of whom eats an average of three carrots a day, and a planting to harvest time of 72 days (right off the seed package) allowing 18 days for equipment down time, we find that each crewmember needs about 11 feet of carrots (planted 1/2 inch apart, 3 * 90 / 24 carrots per foot) If the trays are three inches wide, and 9 inches deep, and they are stacked about two feet apart, then we can put 16 trays side-by-side, and stack four levels high (1st level at 0 feet, 2nd level at 2 feet, etc.) then one "stack" feeds 64 crewmembers and we will need 16 stacks to feed the whole crew. The volume of the "carrot Room" allowing 4 feet at the end of each row, and 2.5 feet between stacks, and placing the water pumps in the 2 feet below the floor level, will be: (2.5 +(16*2)+2.5)*8*15=4440 ft^3 about 126 m^3 the volume of each tray would be 3726 in^3 for a total volume of 3.82E6 in^3 or about 2208 ft^3 assuming another 292 ft^3 for pumps, lines etc, that gives 2500 ft^3 of water (about 71 m^3) which weighs about 1.5E5 lbs or 71600 kg at any one time. Let's assume another 29000 Kg for equip (surely an overstatement, even Kelly must see that) and the total is 1E6 kg for all the fresh carrots you can eat (provided you only eat about 3 a day) Now let's see how many carrots we need to put in frozen storage: 1024 *3 * 365 * 20 years = 2.2E 7 carrots (this already goes beyond the mass limit) now let's see how much space we need, assuming these stored carrots are grown special for us, in that they are rectangular right prisms 6 inches long, and 2 inches to a side, we find that each carrot takes up 24 in^3 or a total of 3.1E5 ft^3 (about 8800 m^3) this weighs about 8.8 E6 kg The warehouse takes eight times the mass, about seventy times the floor space, yeilds smaller portions (24 Cu in vs about 37 Cu in for fresh grown) and the carrots will get progressively worse as time goes on for the stored ones.(can you say 20 year freezer burn - brrr) and if the mission goes beyond twenty years, you have to switch to freeze dried. I don't believe this treatment would work for every food, for example, corn would probably be better stored than grown. but potatoes would probably be best if grown. same with lettuce, tomatoes, Cucumbers, or any other plant with a large food to non-food ratio. I think i can make the same argument for chickens, and perhaps algea eating fish like tiapalia, but cows and pigs would be a definite out. (I still think we should carry a few as breeding stock just in case we do get stuck in the target system, or decide to colonize it. Animals might just be able to survive cryonic sleep by then, and any breeding stock should be stored as frozen and only revived if needed Please also note the following side benefit to growing our food. it makes oxygen. not enough to do without the mechanical scrubbers, but every little bit helps. Also note that it takes less energy to grow the food than to accelerate the extra stored stuff to cruising speed (and if we don't hit .99 C, then Kelly needs even more storage space) This should end the farm vs warehouse debate unless a flaw can be found in my calculations (always a distinct possibility) Kevin From popserver Sun Jan 21 17:00:57 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2279" "Wed" "3" "January" "1996" "15:10:36" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "51" "Carrots" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA28448 for ; Sun, 21 Jan 1996 06:09:13 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12719 (5.67b/IDA-1.5 for ); Sun, 21 Jan 1996 15:10:31 +0100 Message-Id: <199601211410.AA12719@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Carrots Date: Wed, 03 Jan 1996 15:10:36 +0100 To Kevin: >> If we use self reproducing robots, a chip-backery should be on board anyway. > >No, each of the robots would be able to make chips on their own, the process >isn't all that different than making solar cells. Of Course, if they can >make the chips they need, then the ones we need should be no problem. That's what I meant, we have a robot on board with its chip backery. >> That water you need always, even if you use frozen food. > >In fact, you would have less water in a hydroponics system than you would >have in frozen food. I assumed freeze dried food, so a lot if not all (using special prepared food) water would be extracted. Of course it won't be tasty at all. >If the trays are three inches wide, and 9 inches deep, and they are >stacked about two feet apart, then we can put 16 trays side-by-side, and >stack four levels high (1st level at 0 feet, 2nd level at 2 feet, etc.) >then one "stack" feeds 64 crewmembers and we will need 16 stacks to feed >the whole crew. The volume of the "carrot Room" allowing 4 feet at the >end of each row, and 2.5 feet between stacks, and placing the water pumps >in the 2 feet below the floor level, will be: In 72+18 days a member eats (72+18)*3=270 carrots 24 carrots per foot, so a member needs 270/12=11.25 foot One stack has a length of 9*16*4=576 foot So one stack has enough carrots for 576/11.25=51 people. That means 20 stacks instead of 16 >From here I've a real hard time following your calculus... >Please also note the following side benefit to growing our food. it >makes oxygen. not enough to do without the mechanical scrubbers, but >every little bit helps. Also note that it takes less energy to grow the >food than to accelerate the extra stored stuff to cruising speed (and if >we don't hit .99 C, then Kelly needs even more storage space) I wonder, do plants that grow large food (relative to the amount of leaves) use more oxigen than they create? >This should end the farm vs warehouse debate unless a flaw can be found >in my calculations (always a distinct possibility) I found at least one error, and have some doubts about the volume and how much water is there in a single tray? (It took me a while before I figured out that 1 feet is exactly 12 inches) Timothy From popserver Sun Jan 21 17:00:59 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1527" "Wed" "3" "January" "1996" "15:10:40" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "37" "RE: core dump" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA28452 for ; Sun, 21 Jan 1996 06:09:15 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12729 (5.67b/IDA-1.5 for ); Sun, 21 Jan 1996 15:10:38 +0100 Message-Id: <199601211410.AA12729@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: RE: core dump Date: Wed, 03 Jan 1996 15:10:40 +0100 To Brian: >>Why not use the beam alone instead of first beaming particles and then a >>maser beam to ionize them. Also tapping the magnetic field would probably >>have a very bad efficiency. > >I'm not sure I follow you here. Did I mension that I only want launch this >thing using a RPBP or PPP or whatever and figured on using an ion drive to >stop? Yes, I'm sorry. >I didn't think that 10 km^2 per unit would be enough to push the solar >collectors beyond what we could compensate for by adding some weight, >recycling them through Mercury, or whatever. I think the collectors will be lighter than our spacevessel the Asimov so their final velocity will be bigger than that of the Asimov. Adding some weight may help, but the total collecor should become at least 100 times heavier than the Asimov which is not very practical. Recycling to Mercury may not be so nice, the shear forces may rip the 10 km array apart. (I'm not sure how close you want to get) >I'm not convinced that 100 years would be too long for such a monumental >project as reaching the stars. I envoke the cliche that Rome wasn't built >in a day, much less the Roman Empire. I submit that this plan be considered >if nothing better can be done. While building Rome, people had direct profit, namely a save place to live. Building a "big rocket" may only give them a job, but who's going to pay them. >I've got to go RIGHT NOW says my lab monitor. I'll finish my responses >tomorrow. Thanks Tim. Don't thank me, it my job :) Timothy From popserver Sun Jan 21 17:01:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3990" "Wed" "3" "January" "1996" "15:10:45" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "86" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA28468 for ; Sun, 21 Jan 1996 06:09:21 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA12732 (5.67b/IDA-1.5 for ); Sun, 21 Jan 1996 15:10:42 +0100 Message-Id: <199601211410.AA12732@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Engineering Newsletter Date: Wed, 03 Jan 1996 15:10:45 +0100 On Sunday I was writing to Kevin: >I guess that I have more confidence in materials science advances, I >think that a Photovoltaic material can be manufactured that will work in >the high temp/high rad environment Yes, I never argued that, I only wanted to make clear some side-effects. A question where I'm not sure about: Satellites often turn around their axis is that to equal the heat or is it for the gyro-effect? >> >That reminds me of a great new travel method making use of Hiesenberg >> >Uncertainty principle: as Temperature approaches Abs Zero, Momentum >> >becomes zero to the last decimal, and the position becomes _infinite_. >> >> It is not the position that becomes infinite but the PROBABILITY of its >> position that becomes infinite. May look the same, but is different. The > >Ah, yes, I see. I knew that, but must have forgotten it. so i guess it >would work, you just would be able to steer. Oh well. Back to the >drawing board. No it wouldn't work, that was what I tried to explain in the next few lines: >> The fact that a particle can move lightyears be everywhere is As you can >> see, this Although this may look as if it is conflict with the finite speed >> of light there is a deeper understanding that solves this "paradox". > >I'm sorry, I don't understand your language here. Can you please >re-phrase, check your dictionary, or insert the word or words you may >have dropped. I don't understand it either I guess that spelling virus has mutated and uses E-mail as a carrier :} So here is a new try: The fact that a particle can move lightyears in a flash is in conflict with the finite speed of light. So as long as you know the particle is there, it takes an infinite time to cool to absolute zero. >Sorry no, it's part of the great storehouse of knowledge that i have come >across in almost fifteen years of reading every science magazine I can >get my hands on. i think this subject appeared in OMNI, someone >somewhere was claiming to have put a _lot_ of pressure on a small sample >of hydrogen and gotten it to a metal state. Every magazine, thats a lot or are you never in a bookstore? >> >> (Note: Probably all robots will be worn out after a few years, so you may >> >> need 3 or 4 times more than you originally would think, that would only cost >> >> a few days extra) >> > >> >Any robot could probably repaired far cheaper than it could be re-built >> >from scratch, and this could be done at any time, not just at the outset >> >> Repairing is rather difficult, for some dumb replicating machine it is >> probably much easier to make a new one than to look for the non-working part >> and replace it. It is just like a conveyer belt, there is a gain because of >> the repetative task. > >OK, I see. but a small number of units could be devoted to the constant >manufacture of robots (which would then go off and do other things) so >that replacement units were always ready. You could use a small number of units, but I still think it is easier and faster to make a completely new one. (Compare with Earth's throw-away economy) >Perhaps not a problem at all, earth based telescopes track distant stars >all the time. Being placed at a polar position would decrease the >rotational velocity to be countered, and if the problem is >insurmountable, then an orbiting waveguide can be used I wonder if the telescopes do have the precision we need. What should I think of when you are talking about an orbiting waveguide? > means spelling uncertain. i think a Josepson >junction is a tunneling transistor, and it only works in superconducting >conditions, but don't ask me why, maybe steve knows. As far as I know it's not a transistor (i.e. it can be steered by a 3th port). A Josephson junction will give a very distinct Direct Current when placed in a magnetic field (Squid ) Or if an Direct Current is set over the junction it will give a distinct frequency. Timothy From popserver Sun Jan 21 17:01:16 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4150" "Sun" "21" "January" "1996" "09:21:19" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "90" "Re: Carrots" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA05296 for ; Sun, 21 Jan 1996 07:20:01 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 21 Jan 96 09:21:20 -0600 In-Reply-To: <199601211410.AA12719@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Carrots Date: Sun, 21 Jan 1996 09:21:19 -0600 (CST) On Wed, 3 Jan 1996, Timothy van der Linden wrote: > >In fact, you would have less water in a hydroponics system than you would > >have in frozen food. > > I assumed freeze dried food, so a lot if not all (using special prepared > food) water would be extracted. Of course it won't be tasty at all. and there could be severe vitamin depletions. > > >If the trays are three inches wide, and 9 inches deep, and they are > >stacked about two feet apart, then we can put 16 trays side-by-side, and > >stack four levels high (1st level at 0 feet, 2nd level at 2 feet, etc.) > >then one "stack" feeds 64 crewmembers and we will need 16 stacks to feed > >the whole crew. The volume of the "carrot Room" allowing 4 feet at the > >end of each row, and 2.5 feet between stacks, and placing the water pumps > >in the 2 feet below the floor level, will be: > > In 72+18 days a member eats (72+18)*3=270 carrots > 24 carrots per foot, so a member needs 270/12=11.25 foot sorry, I rounded to 11 feet > One stack has a length of 9*16*4=576 foot you have misunderstood the dimensions: (if x and y directions are paralell with the floor, then z is from floor to ceiling) and each tray is 3 inches x, 11.25 feet y and 9 inches z they are placed 16 side-by side giving each level the dimensions 4 feet x, 11.25 feet y, and 9 inches z each level is stacked with a 2 foot level-to-level spacing, giving a stack the dimensions of 4 feet x, 11.25 feet y, and 6 feet z each stack contains 16*4= 64 trays (each 11.25 ft tray feeds one crewmember) and 16*16=1024 > > >From here I've a real hard time following your calculus... it's not calculus, just simple arithmetic. I'm assuming that the end of each row will be taken by machinery, as will the two feet of sub-floor space. there must also be a interstack space to allow people to move about freely, I'm assuming 2.5 feet. Then I calculated the volume of water in the trays and in the supply lines I divided in^3 (or cu. in=cubic inches) by 12^3 to get cu ft (or ft^3) then I multiplied by .02831 to get m^3 the conversion from m^3 to Kg is the standard 1000 Kg/m^3 (yeah, I know that only works for 4 deg centigrade, but let's not quibble over such smallness) after estimating for aditional machinery, I then went on to show how many square "karrots" (6in by 2in by 2in) we would need for each crewmember) and how much space and mass they would take up. (assumeing that the mass of a "Karrot" is just that of the water. > I wonder, do plants that grow large food (relative to the amount of leaves) > use more oxigen than they create? no, the creation of the food (6H20 + 6CO2 + energy --> C6H12O6 +6O2) removes most of that oxygen from the system (plant) it is the non-food portion which consumes oxygen that can not be recovered. you can see this by considering what happens when you eat the food. the oxygen that the plant exhaled combines with the sugar that you ate to produced energy plus CO2 + H2O > > >This should end the farm vs warehouse debate unless a flaw can be found > >in my calculations (always a distinct possibility) > > I found at least one error, and have some doubts about the volume and how > much water is there in a single tray? I think that I have answered your "so-called" errors, as for the volume calculation, here it is again. 3 x * (11.25 *12) y * 9 z (where x,y&z and directions) =3645 in^3 *1024 trays=3.73E6 cu in /(12^3) =2160 ft^3 (well, what do you know there was an error. Luckily it was in my favor, so that means that theoretically al least it takes even _less_ volume) but we still need water in pumps and supply lines and whatnot, so let's call it 2500 ft^3 *.02831 = 70.775 m^3 (I called it 71) =70775 Kg assuming a 29225 Kg for machinery and such = 1 E5 Kg for carrots that take up (2.5+(16*4)+2.5) x * 15 y *8 z =8280 cu ft = 234 m^3 > (It took me a while before I figured out that 1 feet is exactly 12 inches) When you post equations, you can write in SI if you want to but I find when i am estimating sizes, that American system works for me. I will answer any questions you have on relationships etc. Kevin From popserver Mon Jan 22 07:48:45 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3078" "Sun" "21" "January" "1996" "23:48:38" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "69" "Re: Engineering Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA21687 for ; Sun, 21 Jan 1996 21:47:31 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 21 Jan 96 23:48:38 -0600 In-Reply-To: <199601211410.AA12732@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Engineering Newsletter Date: Sun, 21 Jan 1996 23:48:38 -0600 (CST) On Wed, 3 Jan 1996, Timothy van der Linden wrote: > On Sunday I was writing to Kevin: > > >> >That reminds me of a great new travel method making use of Hiesenberg > >> >Uncertainty principle: as Temperature approaches Abs Zero, Momentum > >> >becomes zero to the last decimal, and the position becomes _infinite_. > >> > >> It is not the position that becomes infinite but the PROBABILITY of its > >> position that becomes infinite. May look the same, but is different. The > > > >Ah, yes, I see. I knew that, but must have forgotten it. so i guess it > >would work, you just would be able to steer. Oh well. Back to the > >drawing board. What I _meant_ to say is that we would _not_ be able to steer. The particle would disappear, but you would have no idea where it would appear. > > No it wouldn't work, that was what I tried to explain in the next few lines: > > So here is a new try: > The fact that a particle can move lightyears in a flash is in conflict with > the finite speed of light. So as long as you know the particle is there, it > takes an infinite time to cool to absolute zero. But, particles _can move faster than light, the tunneling effect is known to take exactly zero time to travel some finite distance, therefore speed of light is not the unbreakable limit we have been taught. Of course, tunneling is a _very_ _very_ short range phenomenon. now i suppose if you could controll the tunneling, so that all the atoms in the ship tunneled a few nanometers at the same time, and then immediatly did it again, you could in theory travel faster than the speed of light, since you wouldn't really be in this universe (kinda like hyperspace?) but that begs the question, when an electron tunnels a barrier, where does it go between here and there? > > >Sorry no, it's part of the great storehouse of knowledge that i have come > >across in almost fifteen years of reading every science magazine I can > >get my hands on. i think this subject appeared in OMNI, someone > >somewhere was claiming to have put a _lot_ of pressure on a small sample > >of hydrogen and gotten it to a metal state. > > Every magazine, thats a lot or are you never in a bookstore? > No, i said "that i can get my hands on" meaning there are many that I have never read (like OMNI after they started getting too paranormal) > >Perhaps not a problem at all, earth based telescopes track distant stars > >all the time. Being placed at a polar position would decrease the > >rotational velocity to be countered, and if the problem is > >insurmountable, then an orbiting waveguide can be used > > I wonder if the telescopes do have the precision we need. What should I > think of when you are talking about an orbiting waveguide? Since mercury's rotation is on the order of it's orbital period, i think tracking would not be a problem. Not really sure what orbit a waveguide would occupy As for josepson junctions, i obviously don't know what I'm talking about, so i will shut up. Kevin From popserver Mon Jan 22 22:51:32 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2245" "Mon" "22" "January" "1996" "23:48:59" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "52" "Re: Carrots" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id OAA18155 for ; Mon, 22 Jan 1996 14:48:09 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13506 (5.67b/IDA-1.5 for ); Mon, 22 Jan 1996 23:49:00 +0100 Message-Id: <199601222249.AA13506@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Carrots Date: Mon, 22 Jan 1996 23:48:59 +0100 To Steve: >> >From here I've a real hard time following your calculus... > >it's not calculus, just simple arithmetic. I wanted to boost up you ego ;) (or was it my limited knowledge about the English language again) >I think that I have answered your "so-called" errors, as for the volume >calculation, here it is again. Thanks, now I can see that you where right from the start, it was quite a bunch of data all stacked in a small text, now it is much clearer. >no, the creation of the food (6H20 + 6CO2 + energy --> C6H12O6 +6O2) >removes most of that oxygen from the system (plant) it is the non-food >portion which consumes oxygen that can not be recovered. you can see >this by considering what happens when you eat the food. the oxygen that >the plant exhaled combines with the sugar that you ate to produced energy >plus CO2 + H2O Yes, I knew that, and I'm not certain why I questioned the amount of oxigen created. I think I thought that at night the plant uses oxigen, and the larger the plant-mass, the more oxigen it needs. So I assumed that a large plant with few leaves used more than it would create. Has this thinking any realism? Brian do you know it? >> (It took me a while before I figured out that 1 feet is exactly 12 inches) > >When you post equations, you can write in SI if you want to but I find >when i am estimating sizes, that American system works for me. I will >answer any questions you have on relationships etc. I wasn't planning on doing anything else :) I just had never heard that 1 foot was 12 inches. It's like knowing what a decimetre is and what a centimetre but not knowing that it takes 10 centimetres to get a decimetre. The dodecimal numbering had not reached my mind until yesterday. Do you also use yards, chains and furlongs? As I also noticed there go 16 ounces in a pound. In Dutch there go 5 "ons" in a "pond" and 2 "ponden" in a "kilo"(=1 kg) Long live the English metric system... When are the Americans switching to SI units? The English now have an official law that prohibits the public use (in stores) of the English units. By the way it is here -2 degrees Celcius :) So about 29 degrees Fahrenheit. Yes, the Dutch people always talk about the weather :) Timothy From popserver Mon Jan 22 22:51:34 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1847" "Mon" "22" "January" "1996" "23:48:54" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "39" "Quantum Physics" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id OAA18166 for ; Mon, 22 Jan 1996 14:48:15 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13499 (5.67b/IDA-1.5 for ); Mon, 22 Jan 1996 23:48:53 +0100 Message-Id: <199601222248.AA13499@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Quantum Physics Date: Mon, 22 Jan 1996 23:48:54 +0100 Reply to Steve from Tim >What I _meant_ to say is that we would _not_ be able to steer. The >particle would disappear, but you would have no idea where it would appear. Yes, I understood that. >But, particles _can move faster than light, the tunneling effect is known >to take exactly zero time to travel some finite distance, therefore speed >of light is not the unbreakable limit we have been taught. Of course, >tunneling is a _very_ _very_ short range phenomenon. now i suppose if >you could controll the tunneling, so that all the atoms in the ship >tunneled a few nanometers at the same time, and then immediatly did it >again, you could in theory travel faster than the speed of light, since >you wouldn't really be in this universe (kinda like hyperspace?) but >that begs the question, when an electron tunnels a barrier, where does it >go between here and there? I wonder what magazine you read that stated this. Since I've no written anti-proof I will ask my quantum-physics teacher tomorrow. I know it is a short range (Low energy level) phenomenon (just like all quantum-physics) but that it takes exactly zero time I've never heard of. >Since mercury's rotation is on the order of it's orbital period, i think >tracking would not be a problem. Not really sure what orbit a waveguide >would occupy It still moves 47 km per second, but I don't know how accurate telescopes are, I will try finding someone who knows, until then I've no other comments with respect to the problem. >As for josepson junctions, i obviously don't know what I'm talking about, >so i will shut up. I don't know that much either :| but I listened once to a talk about it (although forgot most of it). When you brought it up, I went to the library to sort it out, what I read there faguely reminded me what I had heard before. Timothy From popserver Tue Jan 23 00:38:26 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2540" "Mon" "22" "January" "1996" "18:35:06" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "54" "Re: Chit-chat Absolutly _NO_ Tech Data" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA27001 for ; Mon, 22 Jan 1996 16:33:47 -0800 (PST) Received: by maroon.tc.umn.edu; Mon, 22 Jan 96 18:35:07 -0600 In-Reply-To: <199601222249.AA13506@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Chit-chat Absolutly _NO_ Tech Data Date: Mon, 22 Jan 1996 18:35:06 -0600 (CST) On Mon, 22 Jan 1996, Timothy van der Linden wrote: > I just had never heard that 1 foot was 12 inches. It's like knowing what a > decimetre is and what a centimetre but not knowing that it takes 10 > centimetres to get a decimetre. The dodecimal numbering had not reached my > mind until yesterday. > Do you also use yards, chains and furlongs? yes, I find yards are a very convienent measurement for most human-scale projects longer than 3 feet. Of course, the metre is only slightly longer, so it's really a moot point (BTW, the word is MOOT, not MUTE. Although I understand what was meant I do find it somewhat irratating) But I wont resort to spell-flameing. I really find yards useful in the 100-300 yd range, as you can easily compare to a football field (that's football, not Soccer) As for Chains, i was not aware that the unit existed, how long is it, and what is the unit of force if you accelerate a one slug mass at g0 for a length of one chain? :) And since I am still working for the Goverment, Please don't use the word furlough (oops, my mistake, I see you said "furlong", oh well no harm then) > As I also noticed there go 16 ounces in a pound. Yup, and eight liquid ounces in a cup, and two cups to the pint, and one pint of water to the pound. Isn't it amazing how all our units of measurement keep being based on water? > When are the Americans switching to SI units? The English now have an > official law that prohibits the public use (in stores) of the English units. I don't know, every time someone brings it up, all the companies cry tears about all the money they will lose. and all the consumer groups (buncha' Ludites) say that they won't possibly be able to keep from being cheated by dishonest manufacturers who will try to make everything seem bigger by displaying the weight, volume or whatever in the smallest SI Units possible. Imagine, you could get 500 ml of soda for only $2.50 why that just 1/2 a penny per ml! >8-0 > > By the way it is here -2 degrees Celcius :) So about 29 degrees Fahrenheit. > Yes, the Dutch people always talk about the weather :) Oh, you guys have it easy! Right now it is -5 farenheit, thats about -23 Celcius. and we won't even talk about the wind chill! Last week, we had wind chills in the -75 Farenheit range (-92 Celcius) anyone know a good sniley for "teeth chattering" all I can think of is *8->< but I think it looks more like "man just got hit in the Gonads" Kevin From popserver Tue Jan 23 01:29:43 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1133" "Mon" "22" "January" "1996" "16:59:46" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "26" "Re: Carrots" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA00565 for ; Mon, 22 Jan 1996 17:12:42 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts1-p45.wolfenet.com [204.157.98.99]) by wolfe.net (8.7.3/8.7) with SMTP id QAA18183; Mon, 22 Jan 1996 16:59:46 -0800 (PST) Message-Id: <199601230059.QAA18183@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, "bmansur@oc.edu From": T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Subject: Re: Carrots Date: Mon, 22 Jan 1996 16:59:46 -0800 (PST) >I wasn't planning on doing anything else :) >I just had never heard that 1 foot was 12 inches. It's like knowing what a >decimetre is and what a centimetre but not knowing that it takes 10 >centimetres to get a decimetre. The dodecimal numbering had not reached my >mind until yesterday. >Do you also use yards, chains and furlongs? Tim Yards we use all the time, though feet is the more common unit of measure. Chains? Maybe not, unless you are a surveyor who measures land units. Furlongs. You bet. In Horse racing the track is measured in furlongs. > >As I also noticed there go 16 ounces in a pound. >In Dutch there go 5 "ons" in a "pond" and 2 "ponden" in a "kilo"(=1 kg) >Long live the English metric system... >When are the Americans switching to SI units? The English now have an >official law that prohibits the public use (in stores) of the English units. > >By the way it is here -2 degrees Celcius :) So about 29 degrees Fahrenheit. >Yes, the Dutch people always talk about the weather :) I work in the biotechnology industry and we use the metric system all the time. Metric isn't hard you just have to use it. Ric From popserver Tue Jan 23 17:01:18 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["21461" "Tue" "23" "January" "1996" "11:29:45" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "550" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA16792 for ; Tue, 23 Jan 1996 08:31:49 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA21905; Tue, 23 Jan 96 11:32:16 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI021803; Tue Jan 23 11:30:25 1996 Received: by most (4.1/SMI-4.1) id AA05985; Tue, 23 Jan 96 11:30:19 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma005965; Tue Jan 23 11:29:48 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA03521; Tue, 23 Jan 96 11:29:44 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Re: Fwd: LIT e-mail discussion group Date: Tue, 23 Jan 1996 11:29:45 -0500 Ok, here my first cut of a summary of all the options we've come up with. (or at least all I can remember.) I figure this is the next step up from Zenons proposed table of contents. We might want to work this up to a summary or central reference page for the LIT server. (More detailed secoundary pages could brach off it.) I'll do more as I get some time. (I working to finish the first draft of my secound novel! So I'll be preoccupeid) Please review and comment. Kelly ============================================================ Mission flight type --------------------------------- One-way * Suicide (explore and die before your time when supplies end) * One-way (Enough supplies are shipped to stay in target system until natural death) (For some inexplicable reason this option has one or two strong advocates within L.I.T.. I want it absolutely known that I neither approve or in anyway support such an option. Nor would I in any credible situation expect it to generate anything but revulsion among the general tax paying public. Kelly Starks - The Author.) >Pros The ship need only be designed for a one time, one way flight. This limits the technical mission risk and requires less resources. Least likelihood of back contaminating Earth. Establishes temporary outpost in starsystem. Allows investigation of the starsystem to continue until al exploration resources are exhausted or worn out. Presumably for a decade or so, depending on the service life of the shuttles or their support facilities, or the service life of the remotes. >Cons To put it mildly the public acceptance of sending explorers out to die the mission and die on the frontier is low. Risking dying maybe, but assigned/left to die by superiors -- no way. Every politician within ear shot will run in front of the closest camera to announce that he or she will personally lead the witch-hunt to track down everyone connected with suggesting this idea. It has been suggested (adamantly) by some members of the group, that this might be justifiable under some situation, or that this would be acceptable as a colonization mission, especially if the colony could be made completely self sufficient from the start. Aside from the technical impossibility of doing the latter. Its unlikely in the extreme, that such risks would be acceptable in an initial mission. At the very least the mission would have to be designed as a two way flight with the option of founding a colony or outpost. Also their would be considerable debate as to why we would want to set up a permanent outpost in a place we don't know anything about, and have no idea if we'd want to stay at. This debate would get louder when the continuing cost of supply flights was discussed. Other problems would be: The potential supply of skilled personnel would obviously drop, if they knew they were to be abandoned in the system when they finished the mission. Especially given that their project life expectancy (due to the lack of 'modern' medical facilities) would drop by a few decades, all but a few years of which they'd spend trapped in a traveling, or derelict ship. Lower information return to Earth due to limited baud rates of interstellar communication. Projected types of crew termination - Voluntary suicide at end of exploration phase of mission. This is likely as some crewmen decide to avoid living out the rest of their years imprisoned in a derelict ship. - Death due to catastrophic failure of vital ship systems as the ship wears out. Obviously the ships systems won't last forever, and can't be rebuilt or replaced completely. At some point it will simply wear out and fail. This could be a single failure, like a major structural breach of the habitation or support systems due to metal fatigue. Or a accumulation of lesser failure as sub-systems begin to unravel. - Death due to medical limitations. Given the limited medical facilities and personnel available on the ship. Crew life expectancies would be far less than those who stayed at home with access to modern medical care. Given the mid 21st century high-tech population would conservatively have a projected life expectancy of 100-130 years, with elongated vigorous years. (Some estimates are far higher.) The crews limited medical life expectancy may still be nearly current US norms. - Death due to chronic crew failure. At some point the crew will simply be to old to maintain and operate the ship, or provide their own medical care. At this point, without a follow on generation to rescue or care for them, they will slowly or quickly die off due to a combination of the above listed causes. --------------------------------- Round trip (Crew returns to Earth with ship at mission end.) >Pros Simplest option, and one with little likely hood of public objection. More likely to get more volunteers and better qualified volunteers for flight. This option implies that the mission is fairly short. I.E. within the professional life of the crew. This would imply its short enough to return information in a useful amount of time. (I.E. it would get there and back, before a later faster flight could do it.) It would return far more information than an interstellar communications link could manage. It obviously avoids the grisly public relations and crew morale problems of a one way mission. >cons Technically more challenging. Getting a ship to the target starsystem is hard enough. Getting it back would make it harder. But this must be traded off against the added complexity of a ship capable of supporting its crew for the rest of their lives. It has to be a fast enough ship to get back in an acceptable amount of time. To slow and theirs no practical reason to send it. --------------------------------- Pick up and return by follow on flight >Pros Most of the advantages of the round trip model, and would allow the first ship to be a mobile research station or other specialized ship, with faster courier ships providing round trip flights. >cons High risk and more complicated. Multiple ship types, and concerns that the first ship might be left stranded. --------------------------------- Crew constructs equipment for return flight This option come up with light/microwave sail craft, beamed power craft, and fuel launcher craft. The crew would construct automated duplicates of the systems that launched the ship from Sol space. >Pros Would establish launcher facilities in both star systems. Which could allowing faster two way flights with specialized fast light ships. The crew might get back faster with their ship using the constructed launcher systems for assistance. cons If they can't build the equipment, they don't get home. The construction phase may require so many resources that the first flight is devoted just to infrastructure construction. With little or no exploration being done in the first mission. This obviously would cool public interest and slow down the return of productive information. --------------------------------- Multi-step. (Ship proceeds to other target star after completion of first mission, in first starsystem.) >Pros One mission explores multiple star systems. >cons Technical feasibility is low since wear and tear on the ship would accumulate, dramatically increasing the likelihood of a catastrophic failure. Because of the extremely long flight times with likely technology, the mission would take so long as to be undesirable. At some point the ship would be superseded by newer faster ships sent straight out from earth, decades after its launch. --------------------------------- Multi-generation Succeeding generations of crew continue the mission >Pros This is the one of the standard concepts suggested to get around the extremely long flight times. Could allow extremely long flight times. cons The ship would have to be huge to support the active crew, retired/incapacitated crew, children, and all the extra support facilities and personnel they would require. The crew, ship, and equipment would need to be even larger than that to allow them to be able to completely rebuild the ship from the inside out as it, and its systems, exceeded their service lives. Any ship that takes that long to get to where it wants to go, will probably find it gets there after newer faster ships from earth. So their is little reason to launch it. The flight would take so long few people would be enthusiastic in launching it, even if they didn't consider the likelihood of faster follow on craft. I.E. why spend money on something you'll never see the results of, nor even ever know if they made it. The follow on generation(s) in the ship will have no allegiance or commitment to the mission or its originators (they, never agreed to anything). The follow on generations would have no hands-on experience with the exploration systems they would be expected to use. Or for that matter, any experience with planets and starsystems. Its harder to get qualified people to go on such a flight. People who want to explore wouldn't want to spend the rest of their life stuck in a ship, knowing they will never contribute anything but their genes. --------------------------------- Hibernation flight >Pros This is the other one of the standard concepts suggested to get around the extremely long flight times. The ship would not need to support the inactive crew. The crew wouldn't need to spend years of their lives waiting around in the ship with nothing to do until they get to the star system. The crew will still be fresh and familiar with their jobs when then are waken up in the star system. >cons The ship systems will still exceeded their service lives, but their may not be enough people around to service them. The sleepers could wind up dying on route as the ship died around them. The sleepers would have to be extremely well shielded from radiation, since their cell repair mechanisms would be as dead as they are. Any ship that takes that long to get to where it wants to go, will probably find it gets there after newer faster ships from earth. The flight would take so long few people would be enthusiastic in launching it. technical political Desirability Risk Feasibility risk Feasibility ------------------------------------------------------------- One-way med-low Medium Ex-high Nil Low Round trip medium medium low High high Pick-up Med-high medium medium medium medium Construct ret high med-high medium medium medium Multi-step Ex-High. med-low low Medium medium Multi-gen Ex-high Low high medium low Hibernation high Low medium medium low ------------------------------- ============================================================ Alternatives --------------------------------- robotic fly by's >Pro Could use a smaller lighter ship and could tolerate longer flight times. >Con requires extremely good A.I. systems and reliability (which may or may not be likely by 2050), and would generate far less public interest. Why bother, you could do nearly as well with huge telescope systems in the Sol star systems --------------------------------- Robotic exploration >Pro Could use a far smaller lighter ship and could tolerate longer flight times. >Con Again requires extremely good A.I. systems and reliability, and would generate less public interest. Would be less capable than a manned mission. ============================================================ Mission purpose --------------------------------- Colonization of planets or moons >Pro Very popular idea with public. Excellent staging area for direct examination of that planet or moon. >Con Expensive. Either the colony would need to be the size of a major city to support all of the specialists needed to support a self sustaining society, or regular (extremely expensive) supply flights from earth would be necessary. On a planet with a Earth-like ecology it would be a biological death trap. Alien microbes, allergens, and other unknowns life forms would easily defeat unprepared Earth mammalian immune systems. On a planet with a non-Earth-like ecology it still could be a biological death trap, and in addition have basic climate and biosphere incompatibilities (Wrong temperatures, air pressures, gravity). Isolation from resources. Ores, energy and raw materials are far harder to access on a planet than in space. Isolation from other planets. Their doesn't seem to be enough practical justification for such a massive undertaking. --------------------------------- Colonization of constructed space platforms >Pro Still may be a very popular idea with public. Excellent staging area for examination of the solar system. Much lower biological threat than on a planet with biosphere. The internal gravity, radiation, and environment can be precisely tailored to humans. Far easier to construct and service than a planet bound colony. Easy access to plentiful resources. (Space is considered so much richer in cheap, easy to access resources and power. That it is expected that Earth's heavy industry will migrate into space in the next century.) Could act as a servicing center and supply port for the starship, or subsequent starships. >Con Expensive. Either the colony would need to be the size of a major city to support all of the specialists needed to support a self sustaining society, or regular (extremely expensive) supply flights from earth would be necessary. Their doesn't seem to be enough practical justification for such a massive undertaking. --------------------------------- Infrastructure construction >Pro This could establish facilities necessary for routine, lower cost, flights between home and this starsystem. >Con Construction could take so many resources that little or no exploration will be done. Less interesting to public than an exploration or colony program. Could be very expensive. -------------------------------------------------- ============================================================ propulsion systems --------------------------------- Fusion feed from internal fuel sources. A fusion powered rocket could cross interstellar distances, and is a near term enough technology to be considered likely for the mid 21st century. Unfortunately the amount of fuel it takes to get such a ship up to a usable speed (at least 1/5th of light speed is necessary. More than a 1/3rd is highly desirable.) is not carryable by such a ship. Since the fuel would weigh hundreds to thousands of times as much as the rest of the ship. For example for a fusion rocket with a specific impulse of 1,000,000. If you wanted to use such an engine to accelerate a ship up to 1/6th the speed of light. The ship would need to carry 147 times its dry weight in fuel. If you want to get to 1/3rd the speed of light, it would need to carry 22,000 times its weight in fuel! Obviously no realistic ship could do this. (Note: a specific impulse of 1,000,000 (A exhaust velocity of 10,000,000m/s) means that the engine gives 1,000,000 pounds of thrust, for one second, for every pound of fuel consumed. This has long been considered a very do-able fusion performance number. For comparison the best chemical engines have a specific impulse of 455.) --------------------------------- Staged fusion ship You start with a 1 billion ton fueled ship cluster driven by a 10 million ton engine and support structure (yeah right.). That engine is powerful enough to push the whole mess with an acceleration rate of 10m/s. When you burn off 95% of your weight in fuel. The ship cluster weighs 50 million tons, 20% of which is a first stage engine/structure that's WAY too powerful. You throw the first stage away and start a smaller second stage. It weighs about 400,000 tons (about as much as 4 aircraft carriers) and can push the 40,000,000 ton ship cluster. When you burn that down to 2,000,000 tons of cluster you throw that away that stage for a 70,000 ton ship with 5-10,000 tons of drive systems. Which can use the remaining 390,000 tons of fuel to get itself into the system. stage total weight (tons) thruster pack and stage structure 1 1,000,000,000 10,000,000 2 40,000,000 400,000 3 2,000,000 70,000 ton ship with 5-10,000 tons of drive systems. This assumes a 100 to 1 thrust to weight ration for a fusion drive systems (which is questionable), and once you get where your going, coming back is out (unless of course you scale the craft up accordingly). But it would give us huge fuel ratios for relativistic flight. So, in theory, a Multi stage fusion craft could get to the star. Assuming of course you can find a billion tons of fusion fuel, and a ship yard in space that can construct a ship the size of an asteroid! Which means in practice the ship is unbuildable. These numbers of course assume the ship has to carry the weight of its fuel. Obviously craft normally have to carry their fuel, but their are some ways around it. --------------------------------- Fusion with externally feed fuel sources A fuel launcher is a linear accelerator mounted somewhere in our solar system. It throws the fuel out in front of where the ship is going to fly. The ship scoops up the fuel as its going along. This has several advantages. The ships engines only need to accelerate the ship itself. (They don't even have to adjust for changing ship weights.) The fuel is accelerated up by the launcher. This means the launcher system (who's power comes from unaccelerated fuel) takes up a large fraction of the load, and the ship saves a lot of energy. Problems are that unless the ship is flying to a starsystem with a operating fuel launcher. It can't fly any faster then a speed it can decelerate from using its onboard fuel reserves. Also, this only works when your close enough to the launcher that it can accurately launch the fuel to you. Once your out of range, your stuck with fuel your caring. Fuel launchers (or beamed power) have the advantage of eliminating the need for the ship to carry the heavy fuel (and power systems). That improves the ships power to weight ratio significantly. But the systems are difficult to do, limit range, and don't seem to help us to slow down. Beamed power Beamed power (or fuel launchers) have the advantage of eliminating the need for the ship to carry the heavy fuel (and power systems). That improves the ships power to weight ratio significantly. But the systems are difficult to do, limit range, and don't seem to help us to slow down. Beamed power systems are most effective as microwave sail craft. But powered electromagnetic drives are possible also. Anti-matter Can be destroyed to create tremendous amounts of energy. Releases over a hundred times as much power per pound of fuel as a fusion reaction. Unfortunately, though it releases more power, this power is harder to directly use to power the ship. It is however far more dangerous to handle. If we could synthesize the thousands of tons of antimatter this would take. It would have the potential of exploding with a force of hundreds of millions of H-bombs. We do not have the technology needed to synthesis, store, or ship anti-matter on this scale, and are not likely to get it by 2050. Ramscoop This idea would allow a ship to scoop up interstellar hydrogen and use it for fuel. Like a fuel launcher system it could accelerate to high speeds without concern for high fuel to weight ratio's. Unfortunately we don't really know what's in interstellar space, but we do know we are in a very thin part of it due to a recent supernova in the area. We might need a scoop thousands of kilometers across for a decent sized ship. We also know that straight hydrogen is very hard to fuse, and doesn't fuse as quickly as we might need. All in all we have no real idea on how to make such a ship work. Future tech The engineering and science we have now and assume we will have in the future will change. Fusion, fission, relativity, quantum mechanics, and a host of other basics of current physics; all were discovered within the last hundred years. We can conservatively expect physics to have changed far more in the next hundred years, then it did in the last hundred years. What technologies that age will have on hand are impossible to guess. They could have matter conversion, hyperlight drives, new understandings of inertia and kinetic energy, or all those and far more. Any of these would dramatically effect our ability to travel between the stars. So even though we can't come up with any practical ideas for exploring the stars now, we can be sure our descendants will find it far easier than we imagine. Kelly Starks ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Tue Jan 23 17:31:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1047" "Tue" "23" "January" "1996" "12:25:51" "-0500" "David Levine" "David@interworld.com" nil "29" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id JAA20851 for ; Tue, 23 Jan 1996 09:25:45 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA275; Tue, 23 Jan 1996 12:30:11 -0500 Message-ID: <31051A1F.788@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Kelly Starks x7066 MS 10-39 CC: Kevin C Houston , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Fwd: LIT e-mail discussion group Date: Tue, 23 Jan 1996 12:25:51 -0500 Kelly Starks x7066 MS 10-39 wrote: > > Ok, here my first cut of a summary of all the options we've come up with. > (or at least all I can remember.) I figure this is the next step up from > Zenons proposed table of contents. We might want to work this up to a > summary or central reference page for the LIT server. (More detailed > secoundary pages could brach off it.) I'll do more as I get some time. (I > working to finish the first draft of my secound novel! So I'll be > preoccupeid) > > Please review and comment. > > Kelly > > ============================================================ I really am working (in my spare time) on a new and improved LIT site. This excellent summary document will, of course, be on it. By the way, I note there is concern about alien biologies overwhelming our biologies. I think it depends upon how advanced the "exo-bacteria" are. There is also the possibility of OUR bacteria completely overwhelming the local ecosystem. This is, of course, undesirable. But not dangerous to us. David From popserver Tue Jan 23 18:32:37 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2313" "Tue" "23" "January" "1996" "13:23:41" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "59" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA25890 for ; Tue, 23 Jan 1996 10:26:09 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA28698; Tue, 23 Jan 96 13:25:57 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI028630; Tue Jan 23 13:24:33 1996 Received: by most (4.1/SMI-4.1) id AA07721; Tue, 23 Jan 96 13:24:31 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma007712; Tue Jan 23 13:23:43 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA01247; Tue, 23 Jan 96 13:23:39 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: David@interworld.com (David Levine) Cc: Kelly Starks x7066 MS 10-39 , Kevin C Houston , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Fwd: LIT e-mail discussion group Date: Tue, 23 Jan 1996 13:23:41 -0500 At 12:25 PM 1/23/96, David Levine wrote: >Kelly Starks x7066 MS 10-39 wrote: >> >> Ok, here my first cut of a summary of all the options we've come up with. >> (or at least all I can remember.) I figure this is the next step up from >> Zenons proposed table of contents. We might want to work this up to a >> summary or central reference page for the LIT server. (More detailed >> secoundary pages could brach off it.) I'll do more as I get some time. (I >> working to finish the first draft of my secound novel! So I'll be >> preoccupeid) >> >> Please review and comment. >> >> Kelly >> >> ============================================================ > >I really am working (in my spare time) on a new and improved >LIT site. This excellent summary document will, of course, >be on it. Yeah, I know how spare time can fly (says the guy whos year old first draft Explorer starship design is still in work). I really miss having the newsletters run. At least we had some hope of getting new people (with new ideas) in that way. >By the way, I note there is concern about alien biologies >overwhelming our biologies. I think it depends upon how >advanced the "exo-bacteria" are. There is also the >possibility of OUR bacteria completely overwhelming the >local ecosystem. This is, of course, undesirable. But >not dangerous to us. > > >David I supposed we havn't been talking about the Earth plague risk much. Nasty environmental impact stament. "Ah, well we could whipe out an entire planetary ecosphere." F.O.E. would nuck NASA as a premtive strike! I don't really think the risks are due to sophistication of bacteria. Just the fact they might each be about the same level of sophistication, but inconpatable with the evolved checks and balences of the other ecology. Sort of like how Kudzu and fire ants (remember them Dave? ;) ) are taking over the southeastern U.S. They arn't better or worse, but different enough to not have a effective local opponent. Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Tue Jan 23 23:59:21 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["989" "Tue" "23" "January" "1996" "18:50:12" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "28" "Re: Bio-sphere-II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA21680 for ; Tue, 23 Jan 1996 15:55:27 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id SAA24390; Tue, 23 Jan 1996 18:50:12 -0500 Message-ID: <960123184705_204915889@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Bio-sphere-II Date: Tue, 23 Jan 1996 18:50:12 -0500 To Kelly: > One of the Good things about places like Biosphere II is not what we will > learn about closed-sytem ecologies (which will be argued no doubt), but > what they teach us about our consumer society. What we learn to do > without and what we find indispensible >> Did you ever lok at all the high tech, high maintenence >> gear it took to keep Bio-shpere going? Oh, and it wasn't enough! >> > Kelly do you know why there was too little oxigen? >> > I've never heard the real reason for it, some thought >> > the oxigen had oxidated with the metal inside >> > the construction. I think that the glass may have >> > filtered out some essential radiation or it may have >> > dimmed the light too much. Nothing flashy. The concrete reacted chemically with something in the soil (can't remember what off hand, sorry) that starved the planets a bit, which cut down oxegen production. >> > Timothy >> > P.S. You guys shouldn't write so fast, I can't keep up... ;) From popserver Wed Jan 24 07:02:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9861" "Wed" "24" "January" "1996" "00:44:33" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "215" "Re: To Kelly" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA15430 for ; Tue, 23 Jan 1996 21:44:30 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id AAA21618; Wed, 24 Jan 1996 00:44:33 -0500 Message-ID: <960123225420_125364389@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: To Kelly Date: Wed, 24 Jan 1996 00:44:33 -0500 RE: Tim replies to Kelly: > > >> OK, but we don't need much manufacturing after the initial build up. It > >> takes much less effort to keep what you have than to build something from > >> scratch. > >> Also a big amount of the 95% spend on manufacturing are the cost for raw > >> materials, I expect the cost of mining raw materials will be less at TC > >> because we can pick the easiest sites. No deep-sea oil drilling, most ores > >> we need will be somewhere near the surface. > > > >Raw materials will be in space. MOst of the best ore beds on earth are > >crashed asteroids. We can go to the source! > > Yes, that's what I meant, so that means a saving of say 80% with respect to > the raw materials. Thus we have 5% spent on R&D and 15% spent on other > man-power. 80% 5% and 15% of what? > >> I still don't see why it is not possible to scale things down. If you need > >> 1 million people to feed 3 million people why can't you do with 100 workers > >> for 300 people? > > > >Actually it takes a couple dozen people to feed 3 million people. But to > >maintain a socyiety it takes millions of differnt professions. You cant > >train 100 people, to each do 60,000 professions and do them well. And we > >arn't in a good position to deal with a lot of sloppy workmanship. > > I hoped you would take the word feed not literally... > Anyway a lot of these professions are sub-divisions of other ones, how many > "professions" are taught at universities and schools? All economic, > administrative, trade and a lot of social professions won't be needed that > bad in a small independant colony. You said yourself that the bigger the > group, the more coordination is needed. I was speaking of professions in the sence of jobs. Yes you could do without a lot of coordinators in a smaller group. But you'll need someone good at all the little jobs a society takes to keep it runing (not to mention a starship). > >Earth got life very quickly after it cooled. Mars may have life. Then their > >is Venus whose crust is wrong which makes it to hoot. What does that give > >you for odds? And is it an average sample? Given the extreams of > >temperature, radiation, chemistry, etc.. that life lives in on earth. > > (icewater, nuclear reactor cores, water hundreds of centigrade above 0, > >deserts) I'ld expect to find life almost anywhere. > > What kind of live lives around nuclear reactor cores? I've heard that some > old corpses were not decomposed because they were burried in a cave where > the radiaton level was so high that even the decomposing bacteria couldn't > live there. Depends on the type of bacteria. Yes a type of bacteria (or maybe an alge?) was found living inside some of the old reactor cores. (I think the new sealed U.S. reactors are to clean to feed them.) They have also found things on the ocean bottom that thrive in water heated to hundreds of defrees C and loaded with heavy metals, or in a few cases that were happily eating old toxic waste dumps. > Mars may have life but if we won't check it we can't be sure, so lets launch > a simple rocked, that takes some samples and analizes them for some traces > of life. Technically we did that with Viking in the '70's. There turned out to be a design defect in one of the three tests, but since all three tests didn't confirm life, the official possition of NASA is that life on Mars has been disproven. > >Venuses temp is NOT due to its atmosphere. Its due to its crust, its a > >fraction of the thickness of earth crust and doesn't insulate well enough to > >keep the surface cool. > > So after the venus cools down slowly, the crust will get thicker and it may > become like Earth? If the sun doesn't swallow it first. Its been cooling for 4.5 billion years, so I think its a bit to slow to make it in time. > >> I'm not sure, would recycling not have a bigger influence on reducing the > >> need for raw materials? Taking all the rubbish down means that the rubbish > >> on Earth would increase, and we already have to much of that. > > > >For ecology purposes moving heavy industry off planet would do more than > >anything else to ease ecology strain. Of course their are international > >political and cultural problems with that (proably a couple of wars with the > >third world). > > Heavy industry on Earth is so dirty because it uses a lot of energy and > doesn't take enough care about its side-products. When fusion becomes > normal, energy is very clean. And in space you can't just leave all the dust > flying around either. Well its not just that. When you have to throw away 90% of the ore you mine to get the remaining good 'refined' part, you generate a lot of waste. Mines tend to be more than a little messy too. Fusion wouldn't intrinsicly change any of that, or much about industry in general. Of course if you move everything off planet you've obviously removed all the sources of Earth based polution. Dust in space isn't a big problem unles you fly through it at high speed. But they probably would do it so the dust was swept up by a planet or blown out by the sun. > >Stuff can't be recycled forever. After a while it just doesn't make any > >sence. Right now we in the (throw it all away) U.S. have litle real problem > >with waste disposal (though an incredible amount of political problems). > > about 80%-90% of our garbage is paper and similar compustables. The small > >fraction of metals and plastics %5ish, can be broken down or shiped into > >space if you crazy enough. Besides if the industry moves off planet to get > >to the resources, the materials to be recycled would need to be shiped up to > >be recycled anyway. > > Shipping up takes large amounts of energy, that means an environmental > problem unless you use fusion power. Well I was assuming fusion or nuclear power (or fussion electric rocket motors), but you could also just assume the fuel is synthasised in space. > >No I ment no food raiseing. Oh, you can have a couple of tomato plants in > >your apartment for recretion. But farm systems weigh too much if your only > >going out for a couple of decades.. > > But why did you speak about veggies(10 tomatos a year?), bread/pasta(corn), > meat/chickens(need food=plants too)? I don't follow. 10 tomatos a year? Why would frozen/irradiated/cryoed food need to be feed? I was just saying I was expecting to feed the crew a normal diet, of normal food, just like they would get from a grocery store. (Withthe exception of very light concentrated emergency rations.) I was expecting to do no/none/zero farming on board the ship. I did mention the crew could grow a few plants in their rooms if they wanted, but all planing assumes no extra solar food production. > >I know ther are dozens of differnt anti-biotics each tailored to various > >things (and most becoming ineffective), but I don't know much more than that. > > You are talking about the small-spectre anti-biotics. The ineffectiveness is > caused mainly by the not finishing the cure and thus allowing the bacteria > to become resistant. > Broad spectre are useful if a bacteria with a lot of different brothers and > sisters is active. Broad specre anti-biotics kill several different bacteria. > > > Why would you think we could fight them? > > Because I think we are smart and that since life is universal it will be > like the organisms we know because the set of chemical reactions that can > support life is very limited. > > In fact if there is alien intelligent live (which is no doubt about) they > will have hands like we do (a finger more or less) just because that is > necessary to get intelligent. (intelligence without a need means nothing to > Darwin) > So they won't have claws or hoofs or fins because these don't need a big > brain to use. > They also will have some light sensative organs (otherwise a even small > brain isn't needed). They will need touch and taste/smell senses. So that > makes them already a lot like the organisms we know. > So, the don't walk on all limbs otherwise the hands cannot get sophisticated > enough. That makes that they are standing up if the have 4 limbs. If they > have more limbs. More limbs is not very efficient for larger organisms that > have to carry a brain of 1 kg. > So they have a brain, would it be like we know it or are there some radical > different possibilities, I don't think there are, as I said before there is > a very limited set of chemical reactions that can be used. > So they have a large brain similar to ours, and need a lot of oxigen to keep > it working. So they have one or 2 longs and hearts. They need to feed > themselfs, so they have teeth. They are probably omnivores, planteaters need > to much time eating, so haven't time to do something else. Carnivores need > all their legs to catch their prey. > OK why not reptiles? They are half coldblooded and can't really function > without some external heat. ??? You need to study life more. There are other chemical combinations then ours that can suport life. Some are radically differnt. Some could not survive the presence of oxegen (as most early earth life couldn't). We don't know they are used, but they could be. As for your quick anatomy breakdown. We have hands and are the preeminent endurence pack preditors on the planet. Our closest runners up are Wolves. We have some notable anotomical differences for two preditors that specialize in the same eco-nich! ;) Our bodies are however, both designed to support the same pack endurance preditor lifestyle. (We are adapted for hotter climates though.) As for the rest. A set of crab claws could work as well as hands. Elephants trucnks can pick up indevidual penuts out of lose debreis, or lift a log. Life has a tendence to to use incredible resourcfullness to kill us. Kelly From popserver Wed Jan 24 07:01:26 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4969" "Tue" "23" "January" "1996" "23:30:55" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "115" "Re: To Kevin and Kelly" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA11217 for ; Tue, 23 Jan 1996 20:30:47 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id XAA26632; Tue, 23 Jan 1996 23:30:55 -0500 Message-ID: <960123225325_125364581@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: To Kevin and Kelly Date: Tue, 23 Jan 1996 23:30:55 -0500 >Actually there is a three way split. Build, repair, carry spares. In our > >case the ship would need to be most concerned about mass. I.E. you might > >be able to make new I.C. chips, but the chips manufacturing equip would > >weigh more then a 40 year supply of circuts. Other things like exotic hard > >to manufacture alloys, composits, cermats, whatever, that the shuttles > >would need. Might require equipment too large to be carried along. > > If we use self reproducing robots, a chip-backery should be on board anyway. Self reproducing robots are a long way off. NASA did some studies that suggested you'ld need human level A.I.'s to make a truly self suficent system, and that assumed you could figure out the design. > >Bottom line things will wear out. When it comes to the point that the > >frames, hulls, main power systems and such have reached their service > >lives. They are not practical to repair, they are scrap. > > You can remelt the metal and make new plates. Assuming that you want plates, can re-refine the metal to eliminate contamination, have the metal manufacturing facilities, etc... > >Unless your > >proposing bringing all the equipment that every high end manufacturer uses. > > Yes, but how much equipment are we talking about, we need machines for: > - Metal treatment > - Plastic treatment > - Semiconductor treatment > - Glas treatment There are whole industries dovoted to each of those topics. They each have tremendous amounts of specialization depending on what sybtype you want. For example Kevlar manufacture and composite aircraft layup, and lexan window manufacture, both fit under "Plastic treatment". Its not like you can just toss an aluminum can into a melter and cast a new can out of it. In a lot of cases to 'recycle' the materials you'ld need to break it back down to to the periodic table, then build it back up. Thats why so little real recycling is done now. (Most materials in the U.S. that are collected for recycling, wind up in special landfills where they are stored as neatly separated garbage.) > >Judging from the fact they work harder at maintaining there lowtech comune > >life style then I do my high tech style, I'm not sure about your > >comparison. > > Using this analogy, won't the futere bring us a complete automatic world, > where no one needs to work? In theory it could, but historically we use most of the extra time to get extra stuff out of life. Amish in trade have far less, work harder for it, and must be partially dependant on the developed world. But they trade that off in complex and inexplicable ways. > >The military is probably a better example. They need rugged equipment, and > >keep it for decades with limited upgrades. But sooner or later it wears > >out and has to be thrown away. > > Yes, but then you have had more than enough time to build a replacement. But they don't have enough people or equipment to do so. So I doubt our little (?) ship would manage it. > >I totaly disagre with your assumption that a most social effort is senceles > >inovation for novelties sake. Thing have to be replaced routinly. MOst > >industries have to live with the fact of market saturation. > > A lot of computers are not being replaced because they completely don't work > any more but just because the competion has faster ones. ---- And because the cost of maintaining the old ones are more the the cost of buying the new one. > >In theory thats true. Reality doesn't live there. The limits are > >practicality. You could break everything down to basic chemicals, ion > >separate them to acceptable prurity, and mine that like ore. But what > >sence would that make? Could you afford to bring along all that equiment? > >Even if you could what advantage would it give you? > > Isn't it possible to make objects with unmixed materials, so that the > recycle-ability is enlarged much more, long enough to last the lives of the > crew. Only if the object can functionwith the simplified subset of materials. Obviously cutting edge or high performance equipment (superconductors, reentry heat shields, aircraft or high streangth alloys, fusion reactors, computer circuts, life support gear, medical equipment, drugs, etc...) can't get by with such lowgrade materials. So those systems would die as soon as they ran out of spare parts. Come to think of it even the rest might not make sence. After all, unalloyed metals wear out and corred FAR faster than alloys. So the alloyed version would outlive several recycled generations of the simpler primal metal version. > >The weight estimates were from the old stanford study. which used mixed > >soil and hydro farming. (Hydro isn't that light, I mean water is heavy > >too.) > > That water you need always, even if you use frozen food. Well you could freze dry it. ;) Actually you would freeze dry or dehydrate a lot of it. (40 year old damp flour? I don't think so!) Kelly From popserver Wed Jan 24 09:19:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["732" "Wed" "24" "January" "1996" "04:12:58" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "21" "Re: Goldin speach" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA26781 for ; Wed, 24 Jan 1996 01:12:50 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id EAA02432; Wed, 24 Jan 1996 04:12:58 -0500 Message-ID: <960123225316_125363913@emout05.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Goldin speach Date: Wed, 24 Jan 1996 04:12:58 -0500 > To Kelly and Zenon, > This is a NASA-newsletter that I got yesterday, it > neatly reflects (y)our discussion which is going on. ADMINISTRATOR GOLDIN ISSUES STATEMENT ON CHALLENGER OBSERVANCE ------- > "I've said many times that safety is the highest > priority at today's NASA. We will not waver from that > commitment. But human beings have always taken great risks > to reap great rewards. Space flight is inherently dangerous > and every member of the NASA team understands those risks. ---- You can probably guess what I think of NASA's political speaches in general. Making this one on the ten year aniversiry of the Challenger loss is in particularly bad taste. Regardless of its being deceptive. Kelly From popserver Wed Jan 24 14:03:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1806" "Wed" "24" "January" "1996" "12:36:53" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "41" "Alien bacteria and biosphere II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id DAA02170 for ; Wed, 24 Jan 1996 03:56:14 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11716 (5.67b/IDA-1.5); Wed, 24 Jan 1996 12:36:53 +0100 Message-Id: <199601241136.AA11716@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Alien bacteria and biosphere II Date: Wed, 24 Jan 1996 12:36:53 +0100 >>By the way, I note there is concern about alien biologies >>overwhelming our biologies. I think it depends upon how >>advanced the "exo-bacteria" are. There is also the >>possibility of OUR bacteria completely overwhelming the >>local ecosystem. This is, of course, undesirable. But >>not dangerous to us. > >I supposed we havn't been talking about the Earth plague risk much. Nasty >environmental impact stament. "Ah, well we could whipe out an entire >planetary ecosphere." F.O.E. would nuck NASA as a premtive strike! Yes, if we have bad luck the planet will be rotting away after a few years. >I don't really think the risks are due to sophistication of bacteria. Just >the fact they might each be about the same level of sophistication, but >inconpatable with the evolved checks and balences of the other ecology. >Sort of like how Kudzu and fire ants (remember them Dave? ;) ) are taking >over the southeastern U.S. They arn't better or worse, but different >enough to not have a effective local opponent. Even if they are less sophisticated, the hazard of killing us is possible, just because we have evolved beyond them too far. ============================================================================ To Kelly: >>Kelly do you know why there was too little oxigen? >>I've never heard the real reason for it, some thought >>the oxigen had oxidated with the metal inside >>the construction. I think that the glass may have >>filtered out some essential radiation or it may have >>dimmed the light too much. > >Nothing flashy. The concrete reacted chemically with something in the soil >(can't remember what off hand, sorry) that starved the planets a bit, which >cut down oxegen production. So the problem could be solved in a new try, or even in the same biosphere. Tim From popserver Wed Jan 24 14:03:13 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4120" "Wed" "24" "January" "1996" "12:36:45" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "87" "Re: Chit-chat Absolutly _NO_ Tech Data" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id DAA02247 for ; Wed, 24 Jan 1996 03:59:54 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11621 (5.67b/IDA-1.5); Wed, 24 Jan 1996 12:36:11 +0100 Message-Id: <199601241136.AA11621@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Chit-chat Absolutly _NO_ Tech Data Date: Wed, 24 Jan 1996 12:36:45 +0100 Ric wrote: >I work in the biotechnology industry and we use the metric system all the >time. Metric isn't hard you just have to use it. Yes, but before one can use it he should know the approximate size. By the way, I thought you worked in your own bead-store, or is that the job of your wife? ============================================================================= Kevin wrote: >yes, I find yards are a very convienent measurement for most human-scale >projects longer than 3 feet. Of course, the metre is only slightly >longer, so it's really a moot point (BTW, the word is MOOT, not MUTE. >Although I understand what was meant it Kelly ;) > I do find it somewhat irratating) But I wont resort to >spell-flameing. I really find yards useful in the 100-300 yd range, as >you can easily compare to a football field (that's football, not Soccer) I have never used "mute point" (I'm not sure though what I would have used if I did) but indeed Kelly used it 3 times since june 1995, 2 times wrong, 1 time right. (I don't mind you correcting some of my errors, if you think you see a stubborn error just mention it in a corner) >As for Chains, i was not aware that the unit existed, how long is it, and >what is the unit of force if you accelerate a one slug mass at g0 for a >length of one chain? :) 1 chain=20 yards 1 fulong=10 chains 1 mile=8 furlongs >And since I am still working for the Goverment, Please don't use the word >furlough (oops, my mistake, I see you said "furlong", oh well no harm then) Maybe you need some furl....? :) >> As I also noticed there go 16 ounces in a pound. > >Yup, and eight liquid ounces in a cup, and two cups to the pint, and one >pint of water to the pound. Isn't it amazing how all our units of >measurement keep being based on water? Well how convenient, you use different a pint for liquid volumes as for dry volumes. I'm wondering how you can keep up with these units. A lot of people in the Netherlands haven't figured out yet how many cubic centimetres are needed to fill one cubic metre. (This is really true, from my own observations I think that maybe 10% can give you the right answer in one try) >> When are the Americans switching to SI units? The English now have an >> official law that prohibits the public use (in stores) of the English units. > >I don't know, every time someone brings it up, all the companies cry >tears about all the money they will lose. and all the consumer groups >(buncha' Ludites) say that they won't possibly be able to keep from being >cheated by dishonest manufacturers who will try to make everything seem >bigger by displaying the weight, volume or whatever in the smallest SI >Units possible. Imagine, you could get 500 ml of soda for only $2.50 why >that just 1/2 a penny per ml! >8-0 Ah well, I wonder how the English system has survived so long, but I also wonder where the SI-system came from (and I don't mean from France where it was officialized) >Oh, you guys have it easy! Right now it is -5 farenheit, thats about -23 >Celcius. and we won't even talk about the wind chill! Last week, we had >wind chills in the -75 Farenheit range (-92 Celcius) And I'm thinking that it's cold here... One thing I'm certain of, I will not come and visit you (no offence :)) >anyone know a good sniley for "teeth chattering" all I can think of is *8->< >but I think it looks more like "man just got hit in the Gonads" Maybe :-|| for a guy who has chattered his teeth too hard. Oh, I asked my quantum physics teacher... first he said you were right, but didn't know exactly how to explain it to me. After the lecture he handed me an article that he had kept in his archives. Amazingly enough, the article convirmed my believe that it takes SOME time to tunnel. The teacher said he might have been wrong and wanted to read it as soon as he had some time. I've not finished it completely, so I will come back to it. About absolute zero, he agreed with me, but wasn't clear about the reasons for not being able to reach absolute zero. Tim From popserver Wed Jan 24 14:03:16 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5414" "Wed" "24" "January" "1996" "12:36:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "111" "Recycling" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id EAA02301 for ; Wed, 24 Jan 1996 04:01:07 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA11728 (5.67b/IDA-1.5); Wed, 24 Jan 1996 12:36:58 +0100 Message-Id: <199601241136.AA11728@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Recycling Date: Wed, 24 Jan 1996 12:36:58 +0100 To Kelly: >> Yes, but how much equipment are we talking about, we need machines for: >> - Metal treatment >> - Plastic treatment >> - Semiconductor treatment >> - Glas treatment > >There are whole industries dovoted to each of those topics. They each have >tremendous amounts of specialization depending on what sybtype you want. For >example Kevlar manufacture and composite aircraft layup, and lexan window >manufacture, both fit under "Plastic treatment". We may need to limit our subsets of needed products, so only one type of window if possible, if it is in the Asimov or in a small planetary vessel. We not only have to offer personal needs, but also general customized methods. >Its not like you can just toss an aluminum can into a melter and cast a new >can out of it. In a lot of cases to 'recycle' the materials you'ld need to >break it back down to to the periodic table, then build it back up. Thats >why so little real recycling is done now. (Most materials in the U.S. that >are collected for recycling, wind up in special landfills where they are >stored as neatly separated garbage.) How many of these separated objects were made for recycling? What I meant was that a lot of plastics should not be used, only the onces that can be recycled easely and more that one time. It doesn't need to be recycled infinite times but at least for some 100 years (10 times). So that does mean that a lot of materials can not be used, maybe too many, then there may be a problem. For the construction of object using several components, they should be build to easely separate them. That would also be handy while repairing them. The way Philips recylces their TV-sets is a good idea of what is needed. Now adays, they make the whole outside out of one kind of plastic, all parts of the TV are easely separated (no brute force needed). A lot of the tin solder is melted of the prints. The prints and their components are crumbled and the metals can easely be extracted. The glass-tube that is made of several kinds of glass, is a bigger problem, but they are working on that. >> Using this analogy, won't the futere bring us a complete automatic world, >> where no one needs to work? > >In theory it could, but historically we use most of the extra time to get >extra stuff out of life. Yes, but we will reach a time when the extra stuff isn't needed for say 21st century living, so that means it isn't necessary to work. Nowadays, we could live a 20th century lifestyle by almost doing nothing. Machines would do almost all the work for us, much less were needed to keep those machines working. Looking to earlier remarks, I'm almost certain that you don't agree to this... By the way, do you think that human AI can be rivalled by "computers" within say 300 years? (Just to get some idea of your ideas) >But they don't have enough people or equipment to do so. So I doubt our >little (?) ship would manage it. Don't they, if the soldiers wouldn't train all day couldn't they replace the army gear in that time? >>A lot of computers are not being replaced because they completely don't work >> any more but just because the competion has faster ones. ---- > >And because the cost of maintaining the old ones are more the the cost of >buying the new one. Yes, that is what I meant when I wrote that a lot of time is spend on R&D, if you would maintain what you have, the computers would become cheaper and cheaper because only the maintenance and rebuild cost would have to be paid. These days a lot of money is paid for the development. Of course this doesn't take in account the time that can be spared after the new products can be used. So if we go one developing like today's society, one day the amount of spare(d) time will be more than the time used for R&D :) >> Isn't it possible to make objects with unmixed materials, so that the >> recycle-ability is enlarged much more, long enough to last the lives of the >> crew. > >Only if the object can functionwith the simplified subset of materials. > Obviously cutting edge or high performance equipment (superconductors, >reentry heat shields, aircraft or high streangth alloys, fusion reactors, >computer circuts, life support gear, medical equipment, drugs, etc...) can't >get by with such lowgrade materials. So those systems would die as soon as >they ran out of spare parts. Indeed, some materials need to be refined to a high degree, but not all. Probably these materials are needed in small amounts, unless you want solar-collectors which need high grade silicon in large quantities. So maybe for a small amount of materials we can allow ourselves small refining machinery. Now indeed the question stays open, how many highgrade materials do we need? I've to think about that. By the way, do we need reentry heat shields, that is only needed if you don't have enough energy to brake yourself. >Come to think of it even the rest might not make sence. After all, unalloyed >metals wear out and corred FAR faster than alloys. So the alloyed version >would outlive several recycled generations of the simpler primal metal >version. Do we need alloyed metal or can we find a substitude, look at the cars that have a body of plastics instead of metal. OK their inner structure is still of steel, but it saves a lot. But is it difficult to recycle steel easely? Timothy If only we had replicators and the energy they needed. From popserver Wed Jan 24 14:13:28 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1772" "Wed" "24" "January" "1996" "09:11:18" "-0500" "David Levine" "David@interworld.com" nil "40" "Re: Alien bacteria and biosphere II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id GAA07268 for ; Wed, 24 Jan 1996 06:10:28 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA313; Wed, 24 Jan 1996 09:15:11 -0500 Message-ID: <31063E06.4C27@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <199601241136.AA11716@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Alien bacteria and biosphere II Date: Wed, 24 Jan 1996 09:11:18 -0500 Timothy van der Linden wrote: > > >>By the way, I note there is concern about alien biologies > >>overwhelming our biologies. I think it depends upon how > >>advanced the "exo-bacteria" are. There is also the > >>possibility of OUR bacteria completely overwhelming the > >>local ecosystem. This is, of course, undesirable. But > >>not dangerous to us. > > > >I supposed we havn't been talking about the Earth plague risk much. Nasty > >environmental impact stament. "Ah, well we could whipe out an entire > >planetary ecosphere." F.O.E. would nuck NASA as a premtive strike! > > Yes, if we have bad luck the planet will be rotting away after a few years. > > >I don't really think the risks are due to sophistication of bacteria. Just > >the fact they might each be about the same level of sophistication, but > >inconpatable with the evolved checks and balences of the other ecology. > >Sort of like how Kudzu and fire ants (remember them Dave? ;) ) are taking > >over the southeastern U.S. They arn't better or worse, but different > >enough to not have a effective local opponent. > > Even if they are less sophisticated, the hazard of killing us is possible, > just because we have evolved beyond them too far. Yes, the worst possible scenario: they kill us off, and we kill them off. Of course, this assumes that alien life would be based off of DNA. I assume it will be - but I suppose there could conceivably be other structures which could self-replicate, compact themselves, and do all of the other things DNA does... If alien life ISN'T based on DNA, it would be unlikely that biocontamination would occur in either direction. Chemical reactions (i.e. allergies, as someone - - Kelly? - - noted earlier) would be the biggest problem... David From popserver Thu Jan 25 04:21:26 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1287" "Wed" "24" "January" "1996" "17:26:09" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "33" "Re: Chit-chat Absolutly _NO_ Tech Data" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA28094 for ; Wed, 24 Jan 1996 17:25:35 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts3-p32.wolfenet.com [204.157.98.214]) by wolfe.net (8.7.3/8.7) with SMTP id RAA02826; Wed, 24 Jan 1996 17:26:09 -0800 (PST) Message-Id: <199601250126.RAA02826@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) Cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Chit-chat Absolutly _NO_ Tech Data Date: Wed, 24 Jan 1996 17:26:09 -0800 (PST) >Ric wrote: > >>I work in the biotechnology industry and we use the metric system all the >>time. Metric isn't hard you just have to use it. > >Yes, but before one can use it he should know the approximate size. >By the way, I thought you worked in your own bead-store, or is that the job >of your wife? I have worked in the Biotech industry for the last 11 years. Deni and I started our bead business 6 years ago. We run it as a "side business" from our home. We advertise in magazines and on the internet. ( Check out our homepage in "Homepages for the homeless" Go to the bottom of the screen and do a search under the letter "D" ) I'd much rather be selling beads. :-) >>As for Chains, i was not aware that the unit existed, how long is it, and >>what is the unit of force if you accelerate a one slug mass at g0 for a >>length of one chain? :) > >1 chain=20 yards 1 fulong=10 chains 1 mile=8 furlongs I just learned something. :-) > >Ah well, I wonder how the English system has survived so long, but I also >wonder where the SI-system came from (and I don't mean from France where it >was officialized) Change is coming. Canada went metic many years ago but I have over heard construction workers still taking about 2 X 4 lumber instaed of in metric units. Ric From popserver Thu Jan 25 18:19:30 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["345" "Thu" "25" "January" "1996" "08:53:18" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "11" "Re: Chit-chat Absolutly _NO_ Tech Data" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA13862 for ; Thu, 25 Jan 1996 06:52:16 -0800 (PST) Received: by maroon.tc.umn.edu; Thu, 25 Jan 96 08:53:19 -0600 In-Reply-To: <199601250126.RAA02826@wolfe.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Ric & Denisse Hedman cc: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Chit-chat Absolutly _NO_ Tech Data Date: Thu, 25 Jan 1996 08:53:18 -0600 (CST) On Wed, 24 Jan 1996, Ric & Denisse Hedman wrote: > our home. We advertise in magazines and on the internet. ( Check out our > homepage in "Homepages for the homeless" Go to the bottom of the screen and > do a search under the letter "D" ) I'd much rather be selling beads. :-) where is "homepages for the homeless?" what's the URL? Kevin From popserver Fri Jan 26 06:54:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["879" "Fri" "26" "January" "1996" "01:50:22" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "29" "Re: Alien bacteria and biosphere II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id WAA25796 for ; Thu, 25 Jan 1996 22:50:24 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id BAA05417; Fri, 26 Jan 1996 01:50:22 -0500 Message-ID: <960125231328_304328005@mail06.mail.aol.com> From: KellySt@aol.com To: David@interworld.com, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Alien bacteria and biosphere II Date: Fri, 26 Jan 1996 01:50:22 -0500 Re: Dave L's Bio hazzard post > Yes, the worst possible scenario: they kill us off, and we > kill them off. Well that would sour kill NASA's funding! ;) > Of course, this assumes that alien life would be based off > of DNA. I assume it will be - but I suppose there could > conceivably be other structures which could self-replicate, > compact themselves, and do all of the other things DNA > does... > If alien life ISN'T based on DNA, it would be unlikely that > biocontamination would occur in either direction. Chemical > reactions (i.e. allergies, as someone - - Kelly? - - noted > earlier) would be the biggest problem... > > David > Folks, only Viruses care what the DNA of the victum is. Bacteria, molds, fungus -- in short every infectious desease that can be cured by anti-biotics. Are only interested in humans as a protean and amino acid source. Kelly From popserver Fri Jan 26 14:41:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5639" "Fri" "26" "January" "1996" "03:43:54" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "126" "Re: Recycling" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id AAA02508 for ; Fri, 26 Jan 1996 00:43:44 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id DAA23554; Fri, 26 Jan 1996 03:43:54 -0500 Message-ID: <960126005312_304399304@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Recycling Date: Fri, 26 Jan 1996 03:43:54 -0500 > To Kelly: ------- > > >> Using this analogy, won't the futere bring us a complete automatic world, > >> where no one needs to work? > > > >In theory it could, but historically we use most of the extra time to get > >extra stuff out of life. > > Yes, but we will reach a time when the extra stuff isn't needed for say 21st > century living, so that means it isn't necessary to work. Nowadays, we could > live a 20th century lifestyle by almost doing nothing. Machines would do > almost all the work for us, much less were needed to keep those machines > working. Looking to earlier remarks, I'm almost certain that you don't agree > to this... I don't agree that most people would agree to much lower standards of living for lower work loads. Now people could easily live the life of people 50-100 years ago with much less work, but that would mean little to no medicine, no T.V., computer, car, stereo, electricity, indoor plumbing, insulated draft free homes, etc... Homes like that are now illegal in the U.S., since they are considered uninhabitable. No doubt our current homes and lifestyle will seem equally squalid and unacceptable to our desendants. So they will work longer to live better. Probably not as long as we do now, and they'ld demand better jobs and treatment; but they would still work. I have great faith in human greed and desire for a better life for themselves, their families, and others they like. > By the way, do you think that human AI can be rivalled by "computers" within > say 300 years? (Just to get some idea of your ideas) Pretty much what I was pitch in DataNet War. We can now build computers with complexity approching the human brain (computers with E 12 bytes of ram have been built, I don't think the human brains much more than that.), so if we can over come a few serious stumpliing blocks we could get human, or more than human intelegence A.I.s fairls quickly. 10 -30 years wouldn't surprize me that much (though I'ld be reluctant to base our starship design on that), certainly within the next century. Given that artificial intelegence would have far fewer limits to its development than organic intelegence, they could progress fairly rapidly. Probably being limited by fundamental limits in avalible information. (You can be a super genius, but if you don't know much more than others, you won't effectivly be much smarter.) > >But they don't have enough people or equipment to do so. So I doubt our > >little (?) ship would manage it. > > Don't they, if the soldiers wouldn't train all day couldn't they replace the > army gear in that time? Only if they built then factories and trained them how to build them. > >>A lot of computers are not being replaced because they completely don't work > >> any more but just because the competion has faster ones. ---- > > > >And because the cost of maintaining the old ones are more the the cost of > >buying the new one. > > Yes, that is what I meant when I wrote that a lot of time is spend on R&D, > if you would maintain what you have, the computers would become cheaper and > cheaper because only the maintenance and rebuild cost would have to be paid. > These days a lot of money is paid for the development. Of course this > doesn't take in account the time that can be spared after the new products > can be used. > So if we go one developing like today's society, one day the amount of > spare(d) time will be more than the time used for R&D :) Computers are becoming cheaper and cheaper by a factor of 100 each decade. > >> Isn't it possible to make objects with unmixed materials, so that the > >> recycle-ability is enlarged much more, long enough to last the lives of the > >> crew. > > > >Only if the object can functionwith the simplified subset of materials. > > Obviously cutting edge or high performance equipment (superconductors, > >reentry heat shields, aircraft or high streangth alloys, fusion reactors, > >computer circuts, life support gear, medical equipment, drugs, etc...) can't > >get by with such lowgrade materials. So those systems would die as soon as > >they ran out of spare parts. > > Indeed, some materials need to be refined to a high degree, but not all. > Probably these materials are needed in small amounts, unless you want > solar-collectors which need high grade silicon in large quantities. > So maybe for a small amount of materials we can allow ourselves small > refining machinery. Now indeed the question stays open, how many highgrade > materials do we need? I've to think about that. > > By the way, do we need reentry heat shields, that is only needed if you > don't have enough energy to brake yourself. Or want to save power in decent. We might as well use it, its one of the few easy tricks we have to save ship power. > >Come to think of it even the rest might not make sence. After all, unalloyed > >metals wear out and corred FAR faster than alloys. So the alloyed version > >would outlive several recycled generations of the simpler primal metal > >version. > > Do we need alloyed metal or can we find a substitude, look at the cars that > have a body of plastics instead of metal. OK their inner structure is still > of steel, but it saves a lot. But is it difficult to recycle steel easely? Its pretty easy to recycle steel, though the quality goes down each cycle. Plastics varry some are easy, some impossible. In general high streagth, corresion resistence, and general durability would require alloys or composites (give or take), which wouldn't recycle very well. > If only we had replicators and the energy they needed. Really. ;) Kelly From popserver Sat Jan 27 03:57:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1094" "Fri" "26" "January" "1996" "09:58:28" "-0500" "David Levine" "David@interworld.com" "<3108EC14.A18@interworld.com>" "28" "Re: Alien bacteria and biosphere II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id GAA18422 for ; Fri, 26 Jan 1996 06:57:36 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA264; Fri, 26 Jan 1996 10:02:06 -0500 Message-ID: <3108EC14.A18@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <960125231328_304328005@mail06.mail.aol.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: KellySt@aol.com CC: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Alien bacteria and biosphere II Date: Fri, 26 Jan 1996 09:58:28 -0500 KellySt@aol.com wrote: > Folks, only Viruses care what the DNA of the victum is. Bacteria, molds, > fungus -- in short every infectious desease that can be cured by > anti-biotics. Are only interested in humans as a protean and amino acid > source. > > Kelly Okay, so reword my previous comments to something along the lines of "this assumes that they require the same protiens, etc. as we do to function"... granted, there's a much greater chance of this than us being infected by an alien virus, but I assume it is still possible that their chemistry/biology can be sufficiently different to make infection harmless. It's not my strong point, but didn't I read somewhere once that while a lot of the proteins, etc. we live on, while they can be either L- or R- versions (left handed or right handed), are all mainly L-? I think I read a short story where someone went through a strange experiment and came out with an R- based system, and no one knew it. He was slowly starving to death because his system couldn't use anything he ate. Or am I barking up the wrong tree here? -David From popserver Sat Jan 27 03:59:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6556" "Sat" "27" "January" "1996" "00:13:31" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "130" "Newsletter of MINILIT" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA17726 for ; Fri, 26 Jan 1996 15:12:13 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA07330 (5.67b/IDA-1.5 for ); Sat, 27 Jan 1996 00:13:19 +0100 Message-Id: <199601262313.AA07330@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Newsletter of MINILIT Date: Sat, 27 Jan 1996 00:13:31 +0100 Tim replies to Kelly: >> >Raw materials will be in space. MOst of the best ore beds on earth are >> >crashed asteroids. We can go to the source! >> >> Yes, that's what I meant, so that means a saving of say 80% with respect to >> the raw materials. Thus we have 5% spent on R&D and 15% spent on other >> man-power. > >80% 5% and 15% of what? Of the total budget spend by companies. You said only 5% was used for R&D, I say about 80% is used by getting the raw materials. Here on Earth those raw materials are difficult to obtain, in space it may be much easier (just scoop the surface) and thus less manpower is needed. >I was speaking of professions in the sence of jobs. Yes you could do without >a lot of coordinators in a smaller group. But you'll need someone good at >all the little jobs a society takes to keep it runing (not to mention a >starship). Like a hairdresser, shoemaker, tailor, dentist, doctor, cook? Are these the jobs you mean? I wonder if we can come up with more than 100 or 1000 completely different jobs that are needed in a starship. >Depends on the type of bacteria. Yes a type of bacteria (or maybe an alge?) >was found living inside some of the old reactor cores. (I think the new >sealed U.S. reactors are to clean to feed them.) They have also found things >on the ocean bottom that thrive in water heated to hundreds of defrees C and >loaded with heavy metals, or in a few cases that were happily eating old >toxic waste dumps. On the bottom of the sea, I can imagine, but in a high radiative field is hard to believe, the DNA would be mutated beyond repair within seconds. Can you recall the source? >> >Venuses temp is NOT due to its atmosphere. Its due to its crust, its a >> >fraction of the thickness of earth crust and doesn't insulate well enough >> >to keep the surface cool. >> >> So after the venus cools down slowly, the crust will get thicker and it may >> become like Earth? > >If the sun doesn't swallow it first. Its been cooling for 4.5 billion years, >so I think its a bit to slow to make it in time. I've been reading some data about Venus, and am quite certain that the biggest part of its temperature not caused by the bad insulating crust. There are is a lot of dust and posionous gasses, which create a very dense atmosphere (90 bar). This dense atmosphere full of greenhouse gasses (much worse than CO2) and the higher radiation level are the main reasons for the higher surface temperature. The percentage of reflected light by Venus is much bigger than the percentage reflected by Earth's atmosphere. So not taking in account greenhouse effects Earth's surface temperature would be 253K while Venus' would be only 230K. You are right though that it is unlikely that Venus would cool down, but for the wrong reason. Most gasses in the atmosphere of Venus would also be released from Earth if it was that near to the Sun. Once it gets released by the extra heat, the greenhouse effect takes over and makes things worse. After the greenhouse effect has taken over, there is no easy way back. >Well its not just that. When you have to throw away 90% of the ore you mine >to get the remaining good 'refined' part, you generate a lot of waste. Mines >tend to be more than a little messy too. Fusion wouldn't intrinsicly change >any of that, or much about industry in general. Of course if you move >everything off planet you've obviously removed all the sources of Earth based >polution. Yeah, that would be nice, wouldn't it... >I don't follow. 10 tomatos a year? Why would frozen/irradiated/cryoed food >need to be feed? I was just saying I was expecting to feed the crew a normal >diet, of normal food, just like they would get from a grocery store. > (Withthe exception of very light concentrated emergency rations.) I was >expecting to do no/none/zero farming on board the ship. I did mention the >crew could grow a few plants in their rooms if they wanted, but all planing >assumes no extra solar food production. My misunderstanding, but can food be kept for 20 years? >??? You need to study life more. There are other chemical combinations then >ours that can suport life. Some are radically differnt. Some could not >survive the presence of oxegen (as most early earth life couldn't). We don't >know they are used, but they could be. Why have these organisms never evolved beyond a single cell? And if they did as you suggest, why did they change to use oxigen? My guess is that it is for the amount of energy released during the oxidation process. What matters for a lot of organisms is the amount of energy they can get. Strangly enough, the organisms with a brain (small or big) are the ones that use most energy... >As for your quick anatomy breakdown. We have hands and are the preeminent >endurence pack preditors on the planet. Our closest runners up are Wolves. We may be partly preditors, but the larger part of our food were vegetables. (In these days of Kingsized burgers that may be hard to believe) Indeed wolves eat also some plants much less than we do. So as far as I'm concerned apes which also eat some small amounts of meat are a lot closer to us. > We have some notable anotomical differences for two preditors that >specialize in the same eco-nich! ;) Our bodies are however, both designed >to support the same pack endurance preditor lifestyle. (We are adapted for >hotter climates though.) I'm not sure anymore what you mean by predator, don't forget our intelligence has brought us far above any other species. So if we hadn't our big brain we would be very poor preditors. >As for the rest. A set of crab claws could work as well as hands. Elephants >trucnks can pick up indevidual penuts out of lose debreis, or lift a log. Although crab claws and elephant truncks are able to pick up things and perform some simple tasks, they don't come near the amount of possibilities that 2 five fingered hands have. Imagine you have a hand with a thumb and a single finger, that would mean a serious handycap all things you could normally do, would not be able or very hard, even many years after you had become customed to it. (And we don't have a solid finger like crabs do) So while an organism gets some usefull "hands" it also gets a smarter brain to use that "hand". Once the brain gets bigger it may be usefull for other purposes too, like better perception, better remembering, better learning. >Life has a tendence to to use incredible resourcfullness to kill us. We have survived a long time though... Timothy From popserver Sat Jan 27 03:59:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2286" "Sat" "27" "January" "1996" "00:13:52" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "52" "Re: Recycling" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA17808 for ; Fri, 26 Jan 1996 15:13:03 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA07349 (5.67b/IDA-1.5 for ); Sat, 27 Jan 1996 00:13:40 +0100 Message-Id: <199601262313.AA07349@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling Date: Sat, 27 Jan 1996 00:13:52 +0100 To Kelly: >I don't agree that most people would agree to much lower standards of living >for lower work loads. Now people could easily live the life of people 50-100 >years ago with much less work, but that would mean little to no medicine, no >T.V., computer, car, stereo, electricity, indoor plumbing, insulated draft >free homes, etc... Homes like that are now illegal in the U.S., since they >are considered uninhabitable. Indeed, I agree. >No doubt our current homes and lifestyle will >seem equally squalid and unacceptable to our desendants. So they will work >longer to live better. It depends on what the gain would be. How fast will technology grow in the futere, will the exponential growth of the last 2 centuries slow down? >Probably not as long as we do now, and they'ld demand >better jobs and treatment; but they would still work. I have great faith in >human greed and desire for a better life for themselves, their families, and >others they like. Again, it depends on the gain. These days, many people decide to live from social finances and not to work and earn more money. >> By the way, do you think that human AI can be rivalled by "computers" >within >> say 300 years? (Just to get some idea of your ideas) > >Pretty much what I was pitch in DataNet War. We can now build computers with >complexity approching the human brain (computers with E 12 bytes of ram have >been built, I don't think the human brains much more than that.) I remember that the human brain has E20 neurons. But it is not especially the memory but the the connection between them, all have to be parallel. >> Yes, that is what I meant when I wrote that a lot of time is spend on R&D, >> if you would maintain what you have, the computers would become cheaper and >> cheaper because only the maintenance and rebuild cost would have to be >> paid. >> These days a lot of money is paid for the development. Of course this >> doesn't take in account the time that can be spared after the new products >> can be used. >> So if we go on developing like today's society, one day the amount of >> spare(d) time will be more than the time used for R&D :) > >Computers are becoming cheaper and cheaper by a factor of 100 each decade. Old computers are another factor 100 cheaper. Tim From popserver Sat Jan 27 03:59:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9692" "Sat" "27" "January" "1996" "00:13:41" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "185" "Re: For Consideration" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA17826 for ; Fri, 26 Jan 1996 15:13:11 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA07338 (5.67b/IDA-1.5 for ); Sat, 27 Jan 1996 00:13:30 +0100 Message-Id: <199601262313.AA07338@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: For Consideration Date: Sat, 27 Jan 1996 00:13:41 +0100 To Brian: >>Ionize interstellar gas, you are talking about it as if you could see it, >>the best guesses are that the there is too few interstellar dust. Only a >>ramscoop with a 1000 km radius may be enough to make some significant use >>of it. >>I still have a hard time imagining how a magsail could work efficient, >>magnetic fields have the peculiarity to be not very bundled. > >When you say "bundled" do you mean that the adjacent fields have a >tendency to repel because of pole orientation and field lines? No, the field doesn't repell itself. With not very bundled I mean that if you create a magnetic field here on Earth, it will "dissolve" very fast. Thus unlike a beam of light it won't be noticed after traveling some distance. Of course if you would use charged particles, the field would stay bundled around them. But then I wonder why not use the particles themselves. Or maybe I'm confused about what you meant by magsail, do you mean a scoop? If so, why is it called a sail and not a scoop? >Or just design a multi-layer sail that takes the bundling problem into >account (isn't that what you already implied was needed?) I'm not completely sure how you plan to make the scoop, but I myself haven't the faintest clue how to build one that could be of any use to us. >As for the interstellar gas. Could we get even .01c down using a >100km wide sail as a paracute if it were deployed throughout the >cruising phase? I'm assumed that we don't try to ionize anything on >our own but use what little ionized material there is of what little >material there is in the first place. Even .01c would help if it >didn't cost us too much power to keep the magnetic sail powered. >Suggestion would be to use superconductive loops. I think that if you restrict yourself to already ionized particles, the amount of mass you can scoop will decrease seriously. >>We use engine thrust and centrifugal forces for gravity, there are no other >>known possibilities. > >I understood this. I meant that we would need to account for >vector accelerations in floor design, such as tilting the floor in >some way to compensate for the centrifugal forces and the >deceleration forces which would probably occur at right angles to >each other. Did any of that make sense? I think the group discussed that some time ago. Indeed the tilt-angle and the rotating-speed of the habitat-ring can be adjusted so that the linear acceleration and centrifugal acceleration together give exactly 1 g at the bottom of the floor (assuming that the linear acceleration does not exceed 1 g). There may be small problems with respect to the 6 tubes (see Kelly's MARS) inside the torus. Because not all points of a tube are as far from the center of rotation, "gravity" will vary slightly along one tube. (In the middle of the tube gravity is lowest) >You say we can't get our many tons of fuel to .3c? I think I must have >confused you somewhere (if I'm the one who is confused then we'll find out >real soon and I sincerely hope that you'll tell me). So, allow me to >rephrase my starship idea (you'll find I have to do that often to get my >ideas collected and across clearly). > >This ship design which we're discussing here is an ion or pulsed fusion >rocket which is launched using external fuel/power/whatever source from the >Sol system during the launch phase. As long as the fuel is prelaunced there is no problem, but you were suggesting to use the fuel as shielding. If you planned using that fuel for deceleration, it could not work because there isn't an engine that can stop it. >I do not believe that the drive will be either durable enough or fuel >efficient enough to run most of the way to Tau Ceti. The acceleration phase >can only last only as long as we can externally fuel/power the ship (say >half a year at 10 m/s^2). OK, If you assume a maximum velocity of 0.33c than you won't need such a long acceleration, but be warned, 0.33c will take at least 35 years to get you to TC. And I'm quite certain that certain members will not agree with such a slow mission. >I admit that I really don't have a clue to how much fuel we'll have to >carry/pre-launch because I don't know the equations that will figure out a >launching ship weight given how powerful the engine is, how fast we want the >ship to go, and how much the hull and fuel weighs. If you know this Tim, >I'm willing to learn. Going on the knowledge that a fusion pulsed rocket >(Daedalus class) is, in theory, capable of achieving a cruise velocity of >.15c with a ship weight of a few thousand tons and a fuel weight close to >50,000 tons, I figure that we could scale it up for a manned mission. > Again, only real stumbling block I see here is finding millions of tons of >3He in the solar system. m=5E7 kg v=.15c --> E = 0.5*m*v^2 = 5E22 Joule (= approx. 1.7E8 kg of fusion fuel that is needed to externally launch it.) >Of course, using Kevin Houston's maser idea would be divine and with it we >could accelerate/declerate the whole way. But I just don't see how he is >going to keep a maser beam on a starship that is 11.8 ly away. Or is it >11.9 or even 12.2 ly. I can't find a single pair of sources that agree on >how far away Tau Ceti is! I think 11.53 ly. >Therefore, I'm not willing to risk a crew, ship, >and mission on the chance that a maser beam, originating from Sol and using >NO deep, deep space correction antennas along the way to Tau Ceti, will >actually be able to stay within even an A.U. of the starship. As I said to >Kevin in the original Core Dump, if he can get his power plug to reach to >Tau Ceti with the accuracy needed, then we are going. Otherwise, while he >is working on that, I want to check out this option. Okay, now I'm really >getting repetitive (I hope you're still reading Tim). I've some one working to find the accuracy of modern telescopes, I hope to hear from him soon. >I proposed that to keep fuel ratio down we launch some of it in the form of >tanker drones to the target star at incrimental speeds of say .01c faster >than the previous tanker (.01c is arbitrary. If we have enough launching >devices, we could cut this even more). The slowest tanker will be a whopper >because it will have to carry enough fuel mass to slow the starship as much >as .15c. Any slower and it will be a century before it reaches its >rendevous position near Tau Ceti. Since the trip at .33c will already take >35 to 40 years, we can launch 60 or so years after Tanker 1. That is almost >half a century to improve the original starship design but probably not >enough to build a much faster one. >By the way. Personally, I don't think that we will be able to try this >manned interstellar mission idea before 2100 or later. Also, because I >don't see maser power reaching across the light-years to fire up the ships >engines for a return trip, and because the crew would have to weigh the ship >down with incredibly huge quantities of scarce fusion fuel/reaction mass, I >don't envision a return trip. Given that the speed limit I am hoping for is >.33c, half the original crew would be dead before they got back. The >mission we are considering here, then is one of exploration and >colonization: something humans should be good at by 2100 or 2200. Hmm, although your ideas may be more realistic than ours (the rest of the group) we had decided(?) that waiting 100 years or more wasn't realistic because we could only guess what techniques would be available. Also such a long mission would NEED to be selfsufficient, and a return mission would be impossible. About selfsufficiency, join the discussion... Brian wrote: >>For the cruising phase of the flight, we can afford to make a habitat that >>is spacous and comfortable. As soon as we want to slow down, however, >>we'll have to stuff the crew into a collection of cramped, space economized, >>modularized, trailer car-like habitats that fit into the cargo bay of the >>space shuttles that we'll use to explore planet surfaces. >>I'll rephrase the preceding. >>You had asked: >>After having thrown away the biggest part of your ship, how are you going >>to >>return? > >We are not. See above. OK, I see your point and indeed as you say it, it would make sence, but as I said before, the ideas of the group are somewhat different, so we have to figure out what we will do. (Is everybody listening?) >Since you made this comment I tried to brainstorm a few ideas. I was not >happy with what I came up with but here they are. >1. Fold and recapture the arrays at recycling stations in orbit of Mercury >and Venus perhaps. >Problems that I see here are with: > a. the stations. They will need positional stablizers, big catching >nets or magnetic breaks if we could fit the solar arrays into magnitizable >capsules, and high automation (course we assume that already. The way I've >been making the automated future out to be I sometimes wonder what the >uneducated masses will be doing for a living. Hopeful computers won't be >thinking for themselves yet or otherwise they'd realize their superior >abilities and TERMINATE us). There would be some counter force against the >incoming array capsules in the form of the relaunching capsules. > b. the array. They must fold themselves, not rip in the prossess, not >get stuck like the hubble telescope's panel did. I'm running out of time >and ideas. All this seems really complicated (and unreliable). And where did you plan to get the energy from to relaunch the arrays? (You'd be better of using that energy directly for the Asimov) Timothy From popserver Sat Jan 27 04:00:01 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2340" "Sat" "27" "January" "1996" "00:41:44" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "54" "Re: Alien bacteria" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA19692 for ; Fri, 26 Jan 1996 15:40:12 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA08268 (5.67b/IDA-1.5 for ); Sat, 27 Jan 1996 00:41:32 +0100 Message-Id: <199601262341.AA08268@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Alien bacteria Date: Sat, 27 Jan 1996 00:41:44 +0100 David wrote: >I was assuming something along the lines of crew members >being infected with some sort of spreading disease which >the other crew members contract, eventually killing the >entire crew. Meanwhile, some crew member happened to >have been carrying some kind of Earth bacteria which >winds up thriving quite well on the new planet, multiplies >quickly, and a few decades later (after our crew is long >dead) is decimating the planet. OK, but you remember, we have many bacteria on and in our body, most of them are necessary to life and without them we would be die very soon. So if we explore alien life we would be best of to use remote controlled robots to get the data we want. I only wonder if we can keep containment levels high enough so that no single cell is exchanged. What I've been thinking about, how would military be interested in these deadly lifeforms? Would they want them, or do they already have enough home-made ones? >Yes - Kelly just pointed this out to me, too. Biology and >chemistry are not my strong points. But I assume there are >still possibilities that would make even their bacteria >incompatible with our biology (i.e. using different >protiens that we do) Yes, I noticed it but then my letter was already posted, that's what happens when one has a pop-mail account and doesn't send a letter as soon as it is finished. >It's not my strong point, but didn't I read somewhere >once that while a lot of the proteins, etc. we live on, >while they can be either L- or R- versions (left handed >or right handed), are all mainly L-? I think I read a >short story where someone went through a strange experiment >and came out with an R- based system, and no one knew it. >He was slowly starving to death because his system couldn't >use anything he ate. Or am I barking up the wrong tree >here? In case no one else knows, I can confirm this idea. Although I wonder if some-one indeed can be "infected" by this disease, the molecules of a certain hand are indeed often not interchangable in chemical reactions. So if the L-bacteria find R-molecules they can't use it (eg. for extracting energy). But I think others who know a bit more about biochemistry will know much more about this. Timothy P.S. Something went wrong while sending this message, so you may have received it twice, sorry. From popserver Sat Jan 27 18:02:11 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5415" "Sat" "27" "January" "1996" "09:29:01" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "102" "Re: For Consideration" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA07277 for ; Sat, 27 Jan 1996 07:27:45 -0800 (PST) Received: by maroon.tc.umn.edu; Sat, 27 Jan 96 09:29:02 -0600 In-Reply-To: <199601262313.AA07338@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: For Consideration Date: Sat, 27 Jan 1996 09:29:01 -0600 (CST) Tim says in response to Brian: > > As long as the fuel is prelaunced there is no problem, but you were > suggesting to use the fuel as shielding. If you planned using that fuel for > deceleration, it could not work because there isn't an engine that can stop > it. only true for internally powered engines, an externally powered MARS design, would be able to carry enough reaction Mass (I hope) to overcome both the photonic thrust, and slow the ship at 1 G (10 m/s^2) Now Brian says > > >Of course, using Kevin Houston's maser idea would be divine and with it we > >could accelerate/declerate the whole way. But I just don't see how he is > >going to keep a maser beam on a starship that is 11.8 ly away. Or is it > >11.9 or even 12.2 ly. I can't find a single pair of sources that agree on > >how far away Tau Ceti is! there is in existence today, a laser interferometer gyroscope, that by all accounts is accurate to within one wavelength of light. assuming you are using something at 580 nanometers, this translates into only 680 Kilometers divergence after 12.0 lightyears. If the maser antenna is wider by that radius, (ie, if the maser beam is 1000 Km in radius, the antenna should be 1680 km in radius) or, if the maser beam is wider than the antenna (just switch the above numbers,) then either the beam will allway rest upon the antenna (in the first case), or the antenna wil allways be within the beam (in the second case) However, Since you missed much of the discussion between the newsletter dying (how that listserver coming Dave?) and the time you joined, I will re-iterate the main monkey-wrench in the system. Before I do so, let me re-state the main Idea. By accelerating the Reaction Mass (RM) to near light speed, we could increase it's momentum endlessly (by approaching the speed of light ever closer) thus allowing less RM to escape out the back of the ship. by using the maser antenna as a "sail", and retro-reflecting most of the energy, we could accelerate away from earth at a nice 1 G (and since the exhaust speed would be C (photons) the RM would be zero. at the turn-around point, instead of reflecting the maser beam, we would convert it to electricity, and accelerate RM in the direction of TC. But there wont be enough energy to overcome the momentum imparted by the photons absorbed, to raise the exhaust speed up to .9996 C. Thus our mass costs will go up. instead of accelerating a small amount of RM to Near-light speed, we will have to accelerate a larger amount to some lower speed (perhaps .75 or .8 C) I would love to tell everyone that I had solved this little mystery, but alas, I have been very busy with school-work. To Dave, Re handedness. While you are correct, in that proteins and sugars come in left and right handed forms, the choice is not completely arbitrary. We use Left-handed Proteins, and right-handed Sugars, (from now on, it's RH and LH) but anything that uses carbon and oxygen will use some kind of sugar. and unfortunately, RH sugar is the most thermodynamically stable. Thus if the Alien bugs use Sugar at all, they will have figured out how to handle RH glucose. as for proteins, This does appear to be an arbitrary choice made by life early in it's developement. It may be that protiens _must_ be LH if Sugars are RH, or it may be something different, However, even if the bugs couldn't digest our proteins, we would not like them eating our glucose and reproduceing ad infinitum. because if they can't eat us, it's a sure bet that our immune system would be completely stymied. on anti-biotics, Kelly is right. all my Bio-Chem Books show that Anti-biotics attacks certain specific Key reactions that all life must use. For example, Sulfa drugs attack the Flavin pathway. Thus unless the bugs are supplied with the component, they cannot survive (unless they have a mutant enzyme which can distinguish between the proper flavin precursor and the sulfa drug. This is what I meant by the evolutionary age of the life being important. We carry many genes within us that are deactivated. Some of them are very old, from the days when we were fish. (fetuses have gills at one point) the same is true of bacteria, they have genes that code for long surpassed chemical weapons. Like this: Bacteria A developes weapon. Bacteria B developes defense to that weapon Bacteria C-Z die for not having the defense, Bacteria B thrives and al future bacteria have the defense gene Bacteria A stops making the weapon, because it is no longer effective. The weapons get better and better, and the more of them your ancestors were exposed to, the better your chance of fending off an attack by an alien bug. A good SF book on this is "The War against the Chtorr" by David Gerald it's a book, not about an invasion, but about an infestation. and the aliens are trying to Chtorraform our planet to suit themselves. but their evolution is much older than ours, so all thier bugs learned how to master penicillin millenia ago (and any other anti-biotic we could come up with) plus all the Chtoran life-forms have chemical weapons and defenses that earth life had never seen before. the long and the short of it is. we are losing. and the human race has to figure out how to survive in a world that is changing around us. anyway, gotta go now. Later Kevin Houston From popserver Sat Jan 27 19:38:06 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1095" "Fri" "26" "January" "1996" "20:05:38" "-0800" "Steve VanDevender" "stevev@efn.org" nil "20" "Re: Alien bacteria and biosphere II" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id JAA15430; Sat, 27 Jan 1996 09:54:28 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id UAA14991; Fri, 26 Jan 1996 20:05:38 -0800 Message-Id: <199601270405.UAA14991@tzadkiel.efn.org> In-Reply-To: <3108EC14.A18@interworld.com> References: <960125231328_304328005@mail06.mail.aol.com> <3108EC14.A18@interworld.com> From: Steve VanDevender To: David@interworld.com (David Levine) Cc: KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Alien bacteria and biosphere II Date: Fri, 26 Jan 1996 20:05:38 -0800 David Levine writes: > It's not my strong point, but didn't I read somewhere > once that while a lot of the proteins, etc. we live on, > while they can be either L- or R- versions (left handed > or right handed), are all mainly L-? I think I read a > short story where someone went through a strange experiment > and came out with an R- based system, and no one knew it. > He was slowly starving to death because his system couldn't > use anything he ate. Or am I barking up the wrong tree > here? This is actually the case. Certain chemical compounds can have two isomers, that have the same formula and the same structure when reflected across a plane of symmetry. Nearly all isomeric compounds used in biology on Earth are L-isomers. Isomers are chemically equivalent when reacting with corresponding isomers of the same handedness, but usually L-isomers and R-isomers are not interchangeable and an isomer of the wrong handedness is not metabolized. On the other hand, getting someone reflected in such a way that all their L-isomers become R-isomers is highly unlikely :-). From popserver Sat Jan 27 22:18:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2502" "Sat" "27" "January" "1996" "23:12:06" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "48" "Re: For Consideration" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id OAA01819 for ; Sat, 27 Jan 1996 14:10:41 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA02840 (5.67b/IDA-1.5 for ); Sat, 27 Jan 1996 23:11:53 +0100 Message-Id: <199601272211.AA02840@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: For Consideration Date: Sat, 27 Jan 1996 23:12:06 +0100 To Kevin: >> As long as the fuel is prelaunced there is no problem, but you were >> suggesting to use the fuel as shielding. If you planned using that fuel for >> deceleration, it could not work because there isn't an engine that can stop >> it. > >only true for internally powered engines, an externally powered MARS >design, would be able to carry enough reaction Mass (I hope) to overcome >both the photonic thrust, and slow the ship at 1 G (10 m/s^2) Yes, I forgot that possibility. >By accelerating the Reaction Mass (RM) to near light speed, we could >increase it's momentum endlessly (by approaching the speed of light ever >closer) thus allowing less RM to escape out the back of the ship. by >using the maser antenna as a "sail", and retro-reflecting most of the >energy, we could accelerate away from earth at a nice 1 G (and since the >exhaust speed would be C (photons) the RM would be zero. at the >turn-around point, instead of reflecting the maser beam, we would convert >it to electricity, and accelerate RM in the direction of TC. But there >wont be enough energy to overcome the momentum imparted by the photons >absorbed, to raise the exhaust speed up to .9996 C. Thus our mass costs >will go up. instead of accelerating a small amount of RM to Near-light >speed, we will have to accelerate a larger amount to some lower speed >(perhaps .75 or .8 C) I would love to tell everyone that I had solved >this little mystery, but alas, I have been very busy with school-work. Yes, it will work, I calculated it. To say it in words you should accept the fact that mass have a better momentum/energy ratio than photons. So this means if you have an amount of energy and want to get the most momentum out of it, then you should accelerate mass and not shine photons. (Of course this means that you have that mass, which as we all know is not favourable in a starship) >on anti-biotics, Kelly is right. all my Bio-Chem Books show that >Anti-biotics attacks certain specific Key reactions that all life must >use. For example, Sulfa drugs attack the Flavin pathway. Thus unless >the bugs are supplied with the component, they cannot survive (unless >they have a mutant enzyme which can distinguish between the proper flavin >precursor and the sulfa drug. This is what I meant by the evolutionary >age of the life being important. So does this mean that we can kill alien-life with anti-biotics as long as their development is not far beyond ours? Timothy From popserver Sun Jan 28 04:46:56 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3035" "Sat" "27" "January" "1996" "21:14:48" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "71" "Re: Recycling" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA15979 for ; Sat, 27 Jan 1996 18:14:57 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id VAA07619; Sat, 27 Jan 1996 21:14:48 -0500 Message-ID: <960127211447_305635422@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Recycling Date: Sat, 27 Jan 1996 21:14:48 -0500 re T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > To Kelly: > > >No doubt our current homes and lifestyle will > >seem equally squalid and unacceptable to our desendants. So they will work > >longer to live better. > > It depends on what the gain would be. How fast will technology grow in the > futere, will the exponential growth of the last 2 centuries slow down? Current indications are that it will accelerate. Given that we are assuming a large space infastructure to build the ship, that would give us all access to VAST raw material resouces and wealth. > >Probably not as long as we do now, and they'ld demand > >better jobs and treatment; but they would still work. I have great faith in > >human greed and desire for a better life for themselves, their families, and > >others they like. > > Again, it depends on the gain. These days, many people decide to live from > social finances and not to work and earn more money. Truem but the welfare is so generous (if you don't mind sucking up to a burecrate dweeb) that the people on welfare (generally lower inteligence and education) would be hard pressed to find a better paying job. > >> By the way, do you think that human AI can be rivalled by "computers" > >within > >> say 300 years? (Just to get some idea of your ideas) > > > >Pretty much what I was pitch in DataNet War. We can now build computers with > >complexity approching the human brain (computers with E 12 bytes of ram have > >been built, I don't think the human brains much more than that.) > > I remember that the human brain has E20 neurons. But it is not especially > the memory but the the connection between them, all have to be parallel. The latest issue of ANALOG science fact/science fiction has an artical on current and future computer and nano-tech systems. We alread have built computers with more processing power, data flow, and memory capacity then the human brain. (As long as the total data flow rate is as great with a non-paralell system, it will work. Now if we could just tell it what to do!) In 20-30 years a 1 human equivelent system should cost what a good home computer costs now. Should help A.I. research quite a bit. ;) > >> Yes, that is what I meant when I wrote that a lot of time is spend on R&D, > >> if you would maintain what you have, the computers would become cheaper and > >> cheaper because only the maintenance and rebuild cost would have to be > >> paid. > >> These days a lot of money is paid for the development. Of course this > >> doesn't take in account the time that can be spared after the new products > >> can be used. > >> So if we go on developing like today's society, one day the amount of > >> spare(d) time will be more than the time used for R&D :) > > > >Computers are becoming cheaper and cheaper by a factor of 100 each decade. > > Old computers are another factor 100 cheaper. No they arn't, even used 10 year old computers arn't that much cheaper. The newer tech is cheaper to build, and faster. Kelly From popserver Sun Jan 28 04:46:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9215" "Sat" "27" "January" "1996" "21:15:05" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "213" "Re: Newsletter of MINILIT" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id SAA16015 for ; Sat, 27 Jan 1996 18:15:41 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id VAA02621; Sat, 27 Jan 1996 21:15:05 -0500 Message-ID: <960127211503_305635619@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Newsletter of MINILIT Date: Sat, 27 Jan 1996 21:15:05 -0500 re T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > Tim replies to Kelly: > > >> >Raw materials will be in space. MOst of the best ore beds on earth are > >> >crashed asteroids. We can go to the source! > >> > >> Yes, that's what I meant, so that means a saving of say 80% with respect to > >> the raw materials. Thus we have 5% spent on R&D and 15% spent on other > >> man-power. > > > >80% 5% and 15% of what? > > Of the total budget spend by companies. You said only 5% was used for R&D, I > say about 80% is used by getting the raw materials. Here on Earth those raw > materials are difficult to obtain, in space it may be much easier (just > scoop the surface) and thus less manpower is needed. Most industries don't spend 80% on raw material (probably more like 10% - 30%) the bulk is in labor costs. So automation will have a big effect. > >I was speaking of professions in the sence of jobs. Yes you could do without > >a lot of coordinators in a smaller group. But you'll need someone good at > >all the little jobs a society takes to keep it runing (not to mention a > >starship). > > Like a hairdresser, shoemaker, tailor, dentist, doctor, cook? Are these the > jobs you mean? > I wonder if we can come up with more than 100 or 1000 completely different > jobs that are needed in a starship. Well it takes 10,000 to operate an aircraft carrer, and far more than that to maintain it. Add in other professions to maintain the entire civilization needed to support them, and you get millions. > >Depends on the type of bacteria. Yes a type of bacteria (or maybe an alge?) > >was found living inside some of the old reactor cores. (I think the new > >sealed U.S. reactors are to clean to feed them.) They have also found things > >on the ocean bottom that thrive in water heated to hundreds of defrees C and > >loaded with heavy metals, or in a few cases that were happily eating old > >toxic waste dumps. > > On the bottom of the sea, I can imagine, but in a high radiative field is > hard to believe, the DNA would be mutated beyond repair within seconds. Can > you recall the source? Several sources. Its an old story of some interest. Last I remember for sure was Science. They were studing the cell repair mecanisms that allow the bacteria they were studying to repair their genetic and tissua damage that fast. (No not in secounds!) They were fairly sure it developed to allow the bacteria to repair themselves fast enough to survive high temperatures, and woundered if it could be transfered to humans. I think they said the cell repair rates were high enough to allow the bacteria to survive thousands of times the human fatal radiation dosage. (Effectivly the radiation couldn't kill them untill it physically cooked them!) > >> >Venuses temp is NOT due to its atmosphere. Its due to its crust, its a > >> >fraction of the thickness of earth crust and doesn't insulate well enough > >> >to keep the surface cool. > >> > >> So after the venus cools down slowly, the crust will get thicker and it may > >> become like Earth? > > > >If the sun doesn't swallow it first. Its been cooling for 4.5 billion years, > >so I think its a bit to slow to make it in time. > > I've been reading some data about Venus, and am quite certain that the > biggest part of its temperature not caused by the bad insulating crust. The latest NASA reports say differently. The Magelin probe showed the thinner crust during its radar scans. > There are is a lot of dust and posionous gasses, which create a very dense > atmosphere (90 bar). This dense atmosphere full of greenhouse gasses (much > worse than CO2) and the higher radiation level are the main reasons for the > higher surface temperature. Given the debacle about greenhouse effect predictions on earth I'm cynical about predictions on alien worlds. Also its generally agreed that if earth was where Venus is, it would not become dramatically hotter. (Well not as dramatic as Venus. You could still live here. But you'll want to move north a bit. ;) ) > >Well its not just that. When you have to throw away 90% of the ore you mine > >to get the remaining good 'refined' part, you generate a lot of waste. Mines > >tend to be more than a little messy too. Fusion wouldn't intrinsicly change > >any of that, or much about industry in general. Of course if you move > >everything off planet you've obviously removed all the sources of Earth based > >polution. > > Yeah, that would be nice, wouldn't it... Unless you sell or to the developed world like the third world does. Expect them to scream as their economies fold. > >I don't follow. 10 tomatos a year? Why would frozen/irradiated/cryoed food > >need to be feed? I was just saying I was expecting to feed the crew a normal > >diet, of normal food, just like they would get from a grocery store. > > (Withthe exception of very light concentrated emergency rations.) I was > >expecting to do no/none/zero farming on board the ship. I did mention the > >crew could grow a few plants in their rooms if they wanted, but all planing > >assumes no extra solar food production. > > My misunderstanding, but can food be kept for 20 years? Sure. We kept some cold war rations around for that long without refrigeration. With high tech, you can keep normal foods almost indefinatly. (Give or take a few problematic fruits like apples.) > >??? You need to study life more. There are other chemical combinations then > >ours that can suport life. Some are radically differnt. Some could not > >survive the presence of oxegen (as most early earth life couldn't). We don't > >know they are used, but they could be. > > Why have these organisms never evolved beyond a single cell? > And if they did as you suggest, why did they change to use oxigen? Algae poluted the atmosphere with so much oxegen everything was killed off. To survive the remaining life forms had to adapt to oxegen or avoid oxegen rich areas (its hard to evolve multi celular when you in those little enclaves.). Even now our cell nucleus is destroyed by oxegen contamination. But we do the best we can. ;) In a world without photosyntisis the non-oxegen forms could still dominate. ---- > >As for your quick anatomy breakdown. We have hands and are the preeminent > >endurence pack preditors on the planet. Our closest runners up are Wolves. > > We may be partly preditors, but the larger part of our food were vegetables. That depends on where we live. A lot of aborigional tribe are still largely pure carnavore. But your right we are omnivors, and eat veges as a large part of our diet. So do wolves and bears, but I never heard anyone debate they were preditors. > (In these days of Kingsized burgers that may be hard to believe) > Indeed wolves eat also some plants much less than we do. So as far as I'm > concerned apes which also eat some small amounts of meat are a lot closer to us. Chips do prey on other animals (even other chimps in some cases), but they are not evolved as endurance pack preditors. Only we and Wolves specialize in that niche. > > We have some notable anotomical differences for two preditors that > >specialize in the same eco-nich! ;) Our bodies are however, both designed > >to support the same pack endurance preditor lifestyle. (We are adapted for > >hotter climates though.) > > I'm not sure anymore what you mean by predator, don't forget our > intelligence has brought us far above any other species. So if we hadn't our > big brain we would be very poor preditors. We were preditors before we had brains. Our ability to track game, and run for extreamly long distences without tiring, are our bigest adaptation for hunting. Thou naturally we wouldn't be nearly as good at it without our inteligence. > >As for the rest. A set of crab claws could work as well as hands. Elephants > >trunks can pick up indevidual penuts out of lose debreis, or lift a log. > > Although crab claws and elephant truncks are able to pick up things and > perform some simple tasks, they don't come near the amount of possibilities > that 2 five fingered hands have. ---- Chavanist! ;) > ---- Imagine you have a hand with a thumb and a > single finger, that would mean a serious handycap all things you could > normally do, would not be able or very hard, even many years after you had > become customed to it. (And we don't have a solid finger like crabs do) But what if you had 6 claw/hands like crabs doi? In general our hands are very good for what we use them for, but their are many alternatives with stregths and weakness over ours. Ours is not the only design that would work, or even the best of all possible hands (we've tested robots with better). > So while an organism gets some usefull "hands" it also gets a smarter brain > to use that "hand". Once the brain gets bigger it may be usefull for other > purposes too, like better perception, better remembering, better learning. Most of our enlarged brain isn't devoted to our hands. Dolphins brains are even larger (proportionally) than ours. (Thou they are not evolved for inteligence.) We are not the only model the universe could use. Kelly From popserver Sun Jan 28 20:32:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2936" "Sun" "28" "January" "1996" "16:16:19" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "53" "Re: Recycling" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA17646 for ; Sun, 28 Jan 1996 07:14:50 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA06718 (5.67b/IDA-1.5 for ); Sun, 28 Jan 1996 16:16:06 +0100 Message-Id: <199601281516.AA06718@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling Date: Sun, 28 Jan 1996 16:16:19 +0100 Reply to Kelly: >Current indications are that it will accelerate. Given that we are assuming >a large space infastructure to build the ship, that would give us all access >to VAST raw material resouces and wealth. Growth is not necessary acceleration, besides that the gain for the public is not always that much. Since the arrival of the televisions, they haven't changed significantly: 30 years ago there was color tv and now they still is. It's a bit more rectangular and has a little bit more quality but those are no real gains. Medical care has grown about as fast as technology but now that we have removed a lot of diseases, it is not growing that fast. Maybe there will come a new acceleration after the genome project, but after a while that will slow down too. All in all, it will become harder and harder to find new bases to accelerate from and after a while (few centuries) most will not accelerate anymore. >> Again, it depends on the gain. These days, many people decide to live from >> social finances and not to work and earn more money. > >True but the welfare is so generous (if you don't mind sucking up to a >burecrate dweeb) that the people on welfare (generally lower inteligence and >education) would be hard pressed to find a better paying job. What happens if the jobs available are to difficult for less intelligent people. After a while machines and AI will take over a lot of work. And if AI really become smarter than we are, then all the work we do would be superfluous. >> I remember that the human brain has E20 neurons. But it is not especially >> the memory but the the connection between them, all have to be parallel. > >The latest issue of ANALOG science fact/science fiction has an artical on >current and future computer and nano-tech systems. We alread have built >computers with more processing power, data flow, and memory capacity then the >human brain. (As long as the total data flow rate is as great with a >non-paralell system, it will work. Now if we could just tell it what to do!) > In 20-30 years a 1 human equivelent system should cost what a good home >computer costs now. Should help A.I. research quite a bit. ;) I find it hard to believe, the GRAY C916 computer has a memory of 16Gb and a computing speed of 16 GFLOPSs. Its I/O bandwith is 13.6 Gb/sec. (It uses a maximum of 3.5E5 Watt, not something you want in your house) The amount of bytes is many orders smaller than the amount of neurons of a human brain (assuming a neuron has about 256 states). As you can see, the GRAY can recall all it's memory in about 1 sec, but than it doesn't do any calculations, which are necessary to make any sense in a neural-network. Further more a few years ago the biggest neural network was 1E5 neurons and they had a hard time of getting them to work together. A fly has a brain of 1E12 neurons (hope I'm right) so it's a long (but not impossible) way to human AI. Timothy From popserver Sun Jan 28 20:32:25 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9331" "Sun" "28" "January" "1996" "16:16:25" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "187" "Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA17650 for ; Sun, 28 Jan 1996 07:14:55 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA06726 (5.67b/IDA-1.5 for ); Sun, 28 Jan 1996 16:16:13 +0100 Message-Id: <199601281516.AA06726@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Hands and brains Date: Sun, 28 Jan 1996 16:16:25 +0100 ReplyTo: Kelly >> Of the total budget spend by companies. You said only 5% was used for R&D, I >> say about 80% is used by getting the raw materials. Here on Earth those raw >> materials are difficult to obtain, in space it may be much easier (just >> scoop the surface) and thus less manpower is needed. > >Most industries don't spend 80% on raw material (probably more like 10% - >30%) the bulk is in labor costs. So automation will have a big effect. OK, I'm wrong. But I don't understand how you can say that automation will decrease the cost dramatically, since you are saying that automats need a lot of maintenance and take a lot of efford to build. >> Like a hairdresser, shoemaker, tailor, dentist, doctor, cook? Are these the >> jobs you mean? >> I wonder if we can come up with more than 100 or 1000 completely different >> jobs that are needed in a starship. > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to >maintain it. Add in other professions to maintain the entire civilization >needed to support them, and you get millions. Are there 10,000 people on one single "boat"? There are only 100-200 people needed to operate a submarine and they are able to live more than 1 year isolated from the outside world. >> On the bottom of the sea, I can imagine, but in a high radiative field is >> hard to believe, the DNA would be mutated beyond repair within seconds. Can >> you recall the source? > >Several sources. Its an old story of some interest. Last I remember for >sure was Science. They were studing the cell repair mecanisms that allow the >bacteria they were studying to repair their genetic and tissua damage that >fast. (No not in secounds!) They were fairly sure it developed to allow the >bacteria to repair themselves fast enough to survive high temperatures, and >woundered if it could be transfered to humans. I think they said the cell >repair rates were high enough to allow the bacteria to survive thousands of >times the human fatal radiation dosage. (Effectivly the radiation couldn't >kill them untill it physically cooked them!) 100 Times, I can believe, even cockroaches can survive that (Of course they have a better armour than bacteria). Now I only wonder how radiation levels can be that low in reactors. I guess these bacteria had found a well shielded place behind some bolds. >The latest NASA reports say differently. The Magelin probe showed the >thinner crust during its radar scans. It may be thin, I wasn't arguing that (It's no wonder if the surface temperature is 450 degree Celcius, the cooling down of the core is much slower). All I said was that most of the higher temperature was due to the greenhous effect. >> There are is a lot of dust and posionous gasses, which create a very dense >> atmosphere (90 bar). This dense atmosphere full of greenhouse gasses (much >> worse than CO2) and the higher radiation level are the main reasons for the >> higher surface temperature. > >Given the debacle about greenhouse effect predictions on earth I'm cynical >about predictions on alien worlds. Forget the predictions, it is proven than several gasses like CO2 and SO2 have very well insulating properties. So the fact that these gasses are present in abundance on Venus means that a greenhouse-effect is responsable for the high temperature. >Also its generally agreed that if earth >was where Venus is, it would not become dramatically hotter. (Well not as >dramatic as Venus. You could still live here. But you'll want to move north >a bit. ;) ) Yes, but that is because Earth has a biosphere. If Earth had to do without that and it would be moved to the place of Venus, then is would heat up and once the greenhouse-effect took over there wouldn't be a way back. >Unless you sell or to the developed world like the third world does. Expect >them to scream as their economies fold. Maybe it's time for them to get their own economies... >> My misunderstanding, but can food be kept for 20 years? > >Sure. We kept some cold war rations around for that long without >refrigeration. With high tech, you can keep normal foods almost indefinatly. > (Give or take a few problematic fruits like apples.) OK, indefinatly, so a humble 60 years would be possible for a single way mission :) >> Why have these organisms never evolved beyond a single cell? >> And if they did as you suggest, why did they change to use oxigen? > >Algae poluted the atmosphere with so much oxegen everything was killed off. > To survive the remaining life forms had to adapt to oxegen or avoid oxegen >rich areas (its hard to evolve multi celular when you in those little >enclaves.). Even now our cell nucleus is destroyed by oxegen contamination. > But we do the best we can. ;) Oh, I thought you were referring to those bacteria living near sea-vulcanos. An organism (like algae) that gets all its energy from direct sunlight is not likely to evolve to a multicellular moving organism, because it takes to much energy to move. So besides the reason that organisms had to use oxygen because otherwise there was no place to stay. >In a world without photosyntisis the non-oxegen forms could still dominate. How? If they used chemicals for their energy, then the supply of those chemicals better be almost infinite. Most of the chemicals that organisms use these days are recycled by using photosyntesis. Only a small fraction of chemicals is freed by vulcanos, hardly enough to sustain a group of lifeforms. >We were preditors before we had brains. Our ability to track game, and run >for extreamly long distences without tiring, are our bigest adaptation for >hunting. Thou naturally we wouldn't be nearly as good at it without our >inteligence. No, we were apes before we had big brains, and apes are no preditors. (I never said that intelligent live could not come from wolves, but if it would they need to change their claws first) >> ---- Imagine you have a hand with a thumb and a >> single finger, that would mean a serious handycap all things you could >> normally do, would not be able or very hard, even many years after you had >> become customed to it. (And we don't have a solid finger like crabs do) > >But what if you had 6 claw/hands like crabs doi? In general our hands are >very good for what we use them for, but their are many alternatives with >stregths and weakness over ours. Ours is not the only design that would >work, or even the best of all possible hands (we've tested robots with >better). Crabs have 8 legs and 2 claws (or scissors) the legs are made for walking (and that's just what they do ;) ). A larger brain needs a larger body, larger bodies need larger legs. Having more than 4 legs will mean a disadvantage because of the extra weight. Even if they had more legs they probably couldn't miss more than 2 of them to permanently free them for hands. Also it would be unlikely that animals that stand on 4 legs would have only a stump to stand on. Having a few small extremeties at each leg gives much more stability. So while there are creatures with more than 4 legs, they aren't likely to support a big brain. That leaves only 2 legs to support the hands. If these 2 hands want to do anything constructive, they better have more than 2 fingers. I also wonder if creatures with gills (using oxigen in the water) could have a large brain. In the water you would need very large gills to get enough oxigen for that brain. Only very large underwater animals could have a big brain, but what would the advantage be for them? They already are at the top of the food-chain. >> So while an organism gets some usefull "hands" it also gets a smarter brain >> to use that "hand". Once the brain gets bigger it may be usefull for other >> purposes too, like better perception, better remembering, better learning. > >Most of our enlarged brain isn't devoted to our hands. Dolphins brains are >even larger (proportionally) than ours. (Thou they are not evolved for >inteligence.) We are not the only model the universe could use. Indeed, most of our brain isn't devoted to anything as far as we know. I meant that a large part is devoted to what you can do with your hands. Suppose you have a large brain, but no hands/legs to make use of it. There would not be any advantage then to have a bigger brain, so it would not evolve. (By the way I couldn't find the meaning of "chavanist", are you sure you spelled it right? (I've an idea of the meaning though)) About Dolphins, they are a species that went back to the sea after living on land, they are also air-breathing. So that may explain some of the size of the brain. You said proportionally, but for intelligence only the absolute size is impotant. Besides that, dolphins are almost the same size we are. So if they have big brains, they have to use them somehow otherwise it would be a bad evolutionary design which is unlikely. I really wonder what a "fish" could do when it was intelligent. It only could use its beak to construct something. Since Dolphins don't seem more intelligent than the average dog, I've some doubts about the real size of their brain, but I haven't any numbers at my diposal to check it. (The latter really is a problem to me, the ideas are clear but the numbers to back it up are often hard to find.) Timothy From popserver Sun Jan 28 20:33:49 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1008" "Sun" "28" "January" "1996" "11:00:37" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "21" "Re: For Consideration" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA22222 for ; Sun, 28 Jan 1996 08:59:08 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 28 Jan 96 11:00:37 -0600 In-Reply-To: <199601272211.AA02840@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: For Consideration Date: Sun, 28 Jan 1996 11:00:37 -0600 (CST) > >on anti-biotics, Kelly is right. all my Bio-Chem Books show that > >Anti-biotics attacks certain specific Key reactions that all life must > >use. For example, Sulfa drugs attack the Flavin pathway. Thus unless > >the bugs are supplied with the component, they cannot survive (unless > >they have a mutant enzyme which can distinguish between the proper flavin > >precursor and the sulfa drug. This is what I meant by the evolutionary > >age of the life being important. > > So does this mean that we can kill alien-life with anti-biotics as long as > their development is not far beyond ours? > Yes, Provided they are LH protein, RH sugar, carbon/oxygen based life forms with DNA utilizing similar Biochem pathways. :) in fact, I would say that _any_ carbon based life could be killed with the proper chemicals (and leave us unharmed,) the Question is how long would it take for us to find the proper chemicals? Kevin (to whom 1E18 Watts of maser energy sounds really good right now) From popserver Sun Jan 28 20:33:57 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3907" "Sun" "28" "January" "1996" "12:05:10" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "81" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA25789 for ; Sun, 28 Jan 1996 10:03:41 -0800 (PST) Received: by maroon.tc.umn.edu; Sun, 28 Jan 96 12:05:11 -0600 In-Reply-To: <199601281516.AA06726@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sun, 28 Jan 1996 12:05:10 -0600 (CST) On Sun, 28 Jan 1996, Timothy van der Linden wrote: > ReplyTo: Kelly > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to > >maintain it. Add in other professions to maintain the entire civilization > >needed to support them, and you get millions. How many of those are actually maintaining the boat, and how many are training to use the weapons that boat is carrying. you keep bringing up the military model Kelly, Are you assuming we are going to have to fight someone/thing. I'll say again, the military is a bad example, many of the people are engaged in specialized activity which has nothing to do with the maintainance of the boat. Another large part of the crew is engaged in activity to repair any damage that the enemy will inflict on them. both groups would not be needed in a star-ship (given the fact that we have written off weapon systems as unescessary, our only defense upon meeting a hostile ship would be to surrender or self-destruct) > > >> My misunderstanding, but can food be kept for 20 years? > > > >Sure. We kept some cold war rations around for that long without > >refrigeration. With high tech, you can keep normal foods almost indefinatly. > > (Give or take a few problematic fruits like apples.) > > OK, indefinatly, so a humble 60 years would be possible for a single way > mission :) Even if we can keep such foods, my carrots example shows that it's cheaper in both mass and space to grow many foods rather than carry them . >> >In a world without photosyntisis the non-oxegen forms could still dominate. you could have photosynthesis, without having oxygen. in our system, plants break down water into hydrogen and oxygen, the hydrogen is tacked onto a CO2 subunit, and then built up into carbo-hydrates. It is no large stretch of the imagination to envision a system where the [Plants] break down H2S and release S2 into the atmosphere tacking the hydrogen onto a CO2 etc etc > (By the way I couldn't find the meaning of "chavanist", are you sure you > spelled it right? (I've an idea of the meaning though)) Kevin speaks: chauvinist -- one who has a prefrence for a particular group of which he is a member. applied to gender, to would mean a man who thought that it is better to be a man than a woman, not really one who thinks that men are better than women, just one who thinks it is better to be a man. It is a milder form of racism. > > About Dolphins, they are a species that went back to the sea after living on > land, they are also air-breathing. So that may explain some of the size of > the brain. > You said proportionally, but for intelligence only the absolute size is > impotant. Besides that, dolphins are almost the same size we are. So if they > have big brains, they have to use them somehow otherwise it would be a bad > evolutionary design which is unlikely. I really wonder what a "fish" could there is some evidence that dolphins devote a large portion of their brains to sonar image processing. and perhaps even language. as to absolute size, that is not true. even the lowly prairie dog has a rudimentary language. It is sophisticated enough to convey the following warnings 1) human approaching 2) dog approaching 3) yellow human approaching (man wearing a yellow coat) 4) black dog approaching from the north In short, the prairie dogs gave different vocalizations when a dog, or a human approached the nest, and gave different vocalizations when the same man wearing different colored jacket walked through. they also gave some indication what the direction of approach was. When a man walked in from the North, the voalizations were recorded, and played back several days later. every member of the prairie dog nest looked, not at the speakers, but to the north. and when Hawk warnings are recorded and played back, they all look to the sky Kevin From popserver Sun Jan 28 20:34:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["861" "Sun" "28" "January" "1996" "10:07:57" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "17" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id KAA25919 for ; Sun, 28 Jan 1996 10:06:36 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts2-p20.wolfenet.com [204.157.98.138]) by wolfe.net (8.7.3/8.7) with SMTP id KAA16494; Sun, 28 Jan 1996 10:07:57 -0800 (PST) Message-Id: <199601281807.KAA16494@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Hands and brains Date: Sun, 28 Jan 1996 10:07:57 -0800 (PST) >>Well it takes 10,000 to operate an aircraft carrer, and far more than that to >>maintain it. Add in other professions to maintain the entire civilization >>needed to support them, and you get millions. > >Are there 10,000 people on one single "boat"? >There are only 100-200 people needed to operate a submarine and they are >able to live more than 1 year isolated from the outside world. The average Aircraft Carrier today has a crew of around 5000. I'm not sure of the number but about 1/2 are there to take care of the planes and fly them. 1/2 of the other 1/2 are there to maintain the systems to launch and retrieve the planes. The rest run the ship. During Viet Nam some carrier had up to 8000 crew. Most of the crewing of Naval ships is to take care of battle losses. Only 1/3 of a crew could sail and fight the ship for a limited amount of time. > From popserver Mon Jan 29 19:05:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1334" "Mon" "29" "January" "1996" "09:49:34" "-0500" "David Levine" "David@interworld.com" nil "27" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id GAA22816 for ; Mon, 29 Jan 1996 06:49:13 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA245; Mon, 29 Jan 1996 09:53:40 -0500 Message-ID: <310CDE7E.17AA@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Kevin C Houston CC: Timothy van der Linden , KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Mon, 29 Jan 1996 09:49:34 -0500 > > > > About Dolphins, they are a species that went back to the sea after living on > > land, they are also air-breathing. So that may explain some of the size of > > the brain. > > You said proportionally, but for intelligence only the absolute size is > > impotant. Besides that, dolphins are almost the same size we are. So if they > > have big brains, they have to use them somehow otherwise it would be a bad > > evolutionary design which is unlikely. I really wonder what a "fish" could I would disagree that only absolute size is important. I'm not positive, but I'm assuming elephant brains are quite larger than human brains. While social and intelligent animals, they're certainly not more intelligent than human beings. Perhaps the absolute size of a certain section of the brain? Like the cerebellum? I don't know enough about elephant anatomy to say whether or not one part of an elephant brain is larger than another part. Actually, my instinct tells me that there is some sort of minimum constant k=c*s, where s is size and c is connectivity (i.e. number of neural connections per brain cell)... so that creatures with smaller brains could still be intelligent if they had a higher density of connections. Well, actually, another possibility is that there is simply a minimum number of connections... -David From popserver Tue Jan 30 05:42:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["19282" "Mon" "29" "January" "1996" "23:54:16" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "450" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA26794 for ; Mon, 29 Jan 1996 20:54:14 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id XAA06422; Mon, 29 Jan 1996 23:54:16 -0500 Message-ID: <960129235413_409873963@mail06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Mon, 29 Jan 1996 23:54:16 -0500 Re: David@interworld.com (David Levine) > > > > > > About Dolphins, they are a species that went back to the sea after living on > > > land, they are also air-breathing. So that may explain some of the size of > > > the brain. > > > You said proportionally, but for intelligence only the absolute size is > > > impotant. Besides that, dolphins are almost the same size we are. So if they > > > have big brains, they have to use them somehow otherwise it would be a bad > > > evolutionary design which is unlikely. I really wonder what a "fish" could > > > I would disagree that only absolute size is important. I'm > not positive, but I'm assuming elephant brains are quite > larger than human brains. While social and intelligent > animals, they're certainly not more intelligent than human > beings. Perhaps the absolute size of a certain section > of the brain? Like the cerebellum? I don't know enough > about elephant anatomy to say whether or not one part of > an elephant brain is larger than another part. Actually, > my instinct tells me that there is some sort of minimum > constant k=c*s, where s is size and c is connectivity (i.e. > number of neural connections per brain cell)... so that > creatures with smaller brains could still be intelligent if > they had a higher density of connections. Well, > actually, another possibility is that there is simply a minimum > number of connections... Yeah, Its assumed that you need a minimum size to have enough cells, for enough interconnections, to get a complex enough brain; But you also need a big enough brain to body ration so the brain has enough excess power to spare on complexity. Dolphin Brains are bigger in size and ratio than human brains. But human brains use a larger fraction (10%) on intelegence. Dolphins sonar cortex is as large as the human visual cortex (30% of human brain), so even though the intelegence centers are far smaller, the total brain is larger. > Re: rddesign@wolfenet.com (Ric & Denisse Hedman) > > >>Well it takes 10,000 to operate an aircraft carrer, and far more than that to > >>maintain it. Add in other professions to maintain the entire civilization > >>needed to support them, and you get millions. > > > >Are there 10,000 people on one single "boat"? > >There are only 100-200 people needed to operate a submarine and they are > >able to live more than 1 year isolated from the outside world. > > The average Aircraft Carrier today has a crew of around 5000. I'm not sure > of the number but about 1/2 are there to take care of the planes and fly > them. 1/2 of the other 1/2 are there to maintain the systems to launch and > retrieve the planes. The rest run the ship. During Viet Nam some carrier had > up to 8000 crew. Opps. I knew Carrier crews were half for the ship, and half for the flight wing. But I couldn't remember if it was 5000 total, or by section. After I sent the E-mail I started to wounder about 10,000 > Re: hous0042@maroon.tc.umn.edu (Kevin C Houston) > > On Sun, 28 Jan 1996, Timothy van der Linden wrote: > > > ReplyTo: Kelly > > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to > > >maintain it. Add in other professions to maintain the entire civilization > > >needed to support them, and you get millions. > > How many of those are actually maintaining the boat, and how many are > training to use the weapons that boat is carrying. ---- No, they generally train crews before they send them out. Fewer ships sink that way. ;) > -----you keep bringing up > the military model Kelly, Are you assuming we are going to have to fight > someone/thing. I'll say again, the military is a bad example, many of > the people are engaged in specialized activity which has nothing to do > with the maintainance of the boat. Another large part of the crew is > engaged in activity to repair any damage that the enemy will inflict on > them. both groups would not be needed in a star-ship (given the fact > that we have written off weapon systems as unescessary, our only defense > upon meeting a hostile ship would be to surrender or self-destruct) I still think the military systems are the best example we have. Certianly the starship will be acting like an aircraft carrier. (Yes a large fraction of the starships crew will be engaged in specialize jobs not related to maintaining the ship. Otherwise why send them?) Also only the military operates large numbers of specialized people, in extreamly isolated, hostile/toxic areas, and gets them out again alive. Also they have done a goodly fraction of the exploration of this planet. I'm not saying we need the ship organized along military ranks, but our equipment will probably be much more like military gear, than anything else. Heavy, tough, built to operate in extreamly bad areas with little civilized infastructure to support them. Some of the equipment may very well be derived from military equipment. (Who else will have decades of bio-warfare experence in their systems designs?) Oh, the starship woun't be armed (though with the power of its engines and interstellar laser com, that might be a debatable point!), the landers and rovers would be armed and armored. I was talking about making sure the equipment could handel an attack by a pack of Tyronasaurus Rex's, and no one seemed to object. > > > >> My misunderstanding, but can food be kept for 20 years? > > > > > >Sure. We kept some cold war rations around for that long without > > >refrigeration. With high tech, you can keep normal foods almost indefinatly. > > > (Give or take a few problematic fruits like apples.) > > > > OK, indefinatly, so a humble 60 years would be possible for a single way > > mission :) > > Even if we can keep such foods, my carrots example shows that it's > cheaper in both mass and space to grow many foods rather than carry them . I did a detailed breakdown of groceries per 20 years vs a selfsustaining farm and found the break even point was 20-30 years (depending). I CAN'T FIND IT!! Its probably in the LIT Newsletters, so if Dave finishes the search engine I can find it that way. Or I might figure out where I put it on my hard drive. Anyway I'll forward that when I can find it. > >> >In a world without photosyntisis the non-oxegen forms could still dominate. > > you could have photosynthesis, without having oxygen. in our system, > plants break down water into hydrogen and oxygen, the hydrogen is tacked > onto a CO2 subunit, and then built up into carbo-hydrates. It is no > large stretch of the imagination to envision a system where the [Plants] > break down H2S and release S2 into the atmosphere tacking the hydrogen > onto a CO2 etc etc Interesting. I hadn't thought of that. I had though of fully chemosynthesis based ecologies like we have here in the deep ocean. But never a different type of photosynthesis. > > (By the way I couldn't find the meaning of "chavanist", are you sure you > > spelled it right? (I've an idea of the meaning though)) Sorry, I keep forgeting you don't always now informal english. > > About Dolphins, they are a species that went back to the sea after living on > > land, they are also air-breathing. ---- snip > > ----- even the lowly prairie dog has a > rudimentary language. It is sophisticated enough to convey the following > warnings ---- > In short, the prairie dogs gave different vocalizations when a dog, or a > human approached the nest, and gave different vocalizations when the same > man wearing different colored jacket walked through. they also gave some > indication what the direction of approach was. When a man walked in from > the North, the voalizations were recorded, and played back several days > later. every member of the prairie dog nest looked, not at the speakers, > but to the north. and when Hawk warnings are recorded and played back, > they all look to the sky Woah?! Neat. I knew a lot of animals and insects had language (certainly my dog demonstrates that effectivly) but I never heard of the prarie dog tests. > > RE: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > > > ReplyTo: Kelly > > >> Of the total budget spend by companies. You said only 5% was used for R&D, I > >> say about 80% is used by getting the raw materials. Here on Earth those raw > >> materials are difficult to obtain, in space it may be much easier (just > >> scoop the surface) and thus less manpower is needed. > > > >Most industries don't spend 80% on raw material (probably more like 10% - > >30%) the bulk is in labor costs. So automation will have a big effect. > > OK, I'm wrong. But I don't understand how you can say that automation > will decrease the cost dramatically, since you are saying that > automats need a lot of maintenance and take a lot of efford to build. So do people. Automation allows a few skilled people to do the work of a larger number of people without automation. It does not allow the automation system to work by itself without people. As long as their are people to fix and operate it, automate systems will work well and productivly. Which is why all large manufacturing industries use them. > >> Like a hairdresser, shoemaker, tailor, dentist, doctor, cook? Are these the > >> jobs you mean? > >> I wonder if we can come up with more than 100 or 1000 completely different > >> jobs that are needed in a starship. > > > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to > >maintain it. Add in other professions to maintain the entire civilization > >needed to support them, and you get millions. > > Are there 10,000 people on one single "boat"? Ok, 5000. > There are only 100-200 people needed to operate a submarine and they are > able to live more than 1 year isolated from the outside world. Submarines are much simpler than carriers, and they seldom operate more than 3 months without coming into port. Actually I can't think of one ever going a year submurged? (RICK!! ??) > >> On the bottom of the sea, I can imagine, but in a high radiative field is > >> hard to believe, the DNA would be mutated beyond repair within seconds. Can > >> you recall the source? > > > >Several sources. Its an old story of some interest. Last I remember for > >sure was Science. They were studing the cell repair mecanisms that allow the > >bacteria they were studying to repair their genetic and tissua damage that > >fast. (No not in secounds!) They were fairly sure it developed to allow the > >bacteria to repair themselves fast enough to survive high temperatures, and > >woundered if it could be transfered to humans. I think they said the cell > >repair rates were high enough to allow the bacteria to survive thousands of > >times the human fatal radiation dosage. (Effectivly the radiation couldn't > >kill them untill it physically cooked them!) > > 100 Times, I can believe, even cockroaches can survive that (Of course they > have a better armour than bacteria). Now I only wonder how radiation levels > can be that low in reactors. I guess these bacteria had found a well > shielded place behind some bolds. No, the bacteria remained directly exposed to the radiation. The only shielding would be the cooling water batween them and the reactor core. > >The latest NASA reports say differently. The Magelin probe showed the > >thinner crust during its radar scans. > > It may be thin, I wasn't arguing that (It's no wonder if the surface > temperature is 450 degree Celcius, the cooling down of the core is much slower). > All I said was that most of the higher temperature was due to the greenhous > effect. Sorry, no the greenhouse effect is considered a dabatable effect at all, even on earth. > >> There are is a lot of dust and posionous gasses, which create a very dense > >> atmosphere (90 bar). This dense atmosphere full of greenhouse gasses (much > >> worse than CO2) and the higher radiation level are the main reasons for the > >> higher surface temperature. > > > >Given the debacle about greenhouse effect predictions on earth I'm cynical > >about predictions on alien worlds. > > Forget the predictions, it is proven than several gasses like CO2 and SO2 > have very well insulating properties. So the fact that these gasses are > present in abundance on Venus means that a greenhouse-effect is > responsable for the high temperature. No it doesn't, it just meen their are insulating gases in the air. It doesn't even tell you if they are keeping heat in, or out. > >Also its generally agreed that if earth > >was where Venus is, it would not become dramatically hotter. (Well not as > >dramatic as Venus. You could still live here. But you'll want to move north > >a bit. ;) ) > > Yes, but that is because Earth has a biosphere. If Earth had to do without > that and it would be moved to the place of Venus, then is would heat up and > once the greenhouse-effect took over there wouldn't be a way back. No, earth biosphere trims its temperature a bit, but not by hundreds of degrees! If that were true Earth would have been unable to ever evolve life. > >Unless you sell or to the developed world like the third world does. Expect > >them to scream as their economies fold. > > Maybe it's time for them to get their own economies... True, but screeming and blaming others is so much easier. > >> My misunderstanding, but can food be kept for 20 years? > > > >Sure. We kept some cold war rations around for that long without > >refrigeration. With high tech, you can keep normal foods almost indefinatly. > > (Give or take a few problematic fruits like apples.) > > OK, indefinatly, so a humble 60 years would be possible for a single way > mission :) Well, you wouldn't starve anyway. > >> Why have these organisms never evolved beyond a single cell? > >> And if they did as you suggest, why did they change to use oxigen? > > > >Algae poluted the atmosphere with so much oxegen everything was killed off. > > To survive the remaining life forms had to adapt to oxegen or avoid oxegen > >rich areas (its hard to evolve multi celular when you in those little > >enclaves.). Even now our cell nucleus is destroyed by oxegen contamination. > > But we do the best we can. ;) > > Oh, I thought you were referring to those bacteria living near sea-vulcanos. Some are there, or in stagnent pools (like parts of SanFransico bay) that have little or no oxegen. But no large ecologies can develop in such isolation. > >In a world without photosyntisis the non-oxegen forms could still dominate. > > How? If they used chemicals for their energy, then the supply of those > chemicals better be almost infinite. Most of the chemicals that organisms > use these days are recycled by using photosyntesis. Only a small fraction of > chemicals is freed by vulcanos, hardly enough to sustain a group of lifeforms. Depends on the planets and its chemistry. > >We were preditors before we had brains. Our ability to track game, and run > >for extreamly long distences without tiring, are our bigest adaptation for > >hunting. Thou naturally we wouldn't be nearly as good at it without our > >inteligence. > > No, we were apes before we had big brains, and apes are not preditors. We evolved from chimps, which are predators. (Unlike Gorillas.) Those chimps evolved (after some odd twists) into plains preditors and scavengers. We developed that (and primative tool making), before our brains expanded much. > (I never said that intelligent live could not come from wolves, but if it > would they need to change their claws first) They could develop intelegence. A need for that just mean you have complex problem between you and a steed meal. Wolve greatest problem toward developing intelegence is that they are to good at what they do. Racoons or Otters would be a better bet. They depend more on cleverness, and use hands and some (unfashioned) tools. > >> ---- Imagine you have a hand with a thumb and a > >> single finger, that would mean a serious handycap all things you could > >> normally do, would not be able or very hard, even many years after you had > >> become customed to it. (And we don't have a solid finger like crabs do) > > > >But what if you had 6 claw/hands like crabs doi? In general our hands are > >very good for what we use them for, but their are many alternatives with > >stregths and weakness over ours. Ours is not the only design that would > >work, or even the best of all possible hands (we've tested robots with > >better). > > Crabs have 8 legs and 2 claws (or scissors) the legs are made for walking > (and that's just what they do ;) ). They have about 6 - 8 claws, but the inner ones are very small and specialized for tearing down food for the mouth. > A larger brain needs a larger body, larger bodies need larger legs. Having > more than 4 legs will mean a disadvantage because of the extra weight. > Even if they had more legs they probably couldn't miss more than 2 of them > to permanently free them for hands. > > Also it would be unlikely that animals that stand on 4 legs would have only > a stump to stand on. Having a few small extremeties at each leg gives much > more stability. > > So while there are creatures with more than 4 legs, they aren't likely to > support a big brain. > That leaves only 2 legs to support the hands. If these 2 hands want to do > anything constructive, they better have more than 2 fingers. ???!! You have some strange and unsupported assumptions there. MOst of earths walking life forms have more than 4 legs. Almost all of the rest have 4. Given that humans are fairly small as animals go, I can't see any justification in assuming large 4 or six limbed creatures are impossible. Hell we have predatores in north america that are almost a ton! > I also wonder if creatures with gills (using oxigen in the water) could have > a large brain. In the water you would need very large gills to get enough > oxigen for that brain. Only very large underwater animals could have a big > brain, but what would the advantage be for them? They already are at the top > of the food-chain. Gills in water actually need les body mass than lungs in air. > >> So while an organism gets some usefull "hands" it also gets a smarter brain > >> to use that "hand". Once the brain gets bigger it may be usefull for other > >> purposes too, like better perception, better remembering, better learning. > > > >Most of our enlarged brain isn't devoted to our hands. Dolphins brains are > >even larger (proportionally) than ours. (Thou they are not evolved for > >inteligence.) We are not the only model the universe could use. > > Indeed, most of our brain isn't devoted to anything as far as we know. -- Actually we do know what all the centers of the brain do, just not how they do it. > --- I > meant that a large part is devoted to what you can do with your hands. > Suppose you have a large brain, but no hands/legs to make use of it. There > would not be any advantage then to have a bigger brain, so it would not evolve. The biggest section of the human brain evolved to use the eyes, not hands. Niether are used in itelegence, that evolved separatly. Kelly From popserver Tue Jan 30 05:42:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["19282" "Tue" "30" "January" "1996" "00:12:27" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "450" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA27826 for ; Mon, 29 Jan 1996 21:12:25 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id AAA22296; Tue, 30 Jan 1996 00:12:27 -0500 Message-ID: <960130001226_209768422@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Tue, 30 Jan 1996 00:12:27 -0500 Re: David@interworld.com (David Levine) > > > > > > About Dolphins, they are a species that went back to the sea after living on > > > land, they are also air-breathing. So that may explain some of the size of > > > the brain. > > > You said proportionally, but for intelligence only the absolute size is > > > impotant. Besides that, dolphins are almost the same size we are. So if they > > > have big brains, they have to use them somehow otherwise it would be a bad > > > evolutionary design which is unlikely. I really wonder what a "fish" could > > > I would disagree that only absolute size is important. I'm > not positive, but I'm assuming elephant brains are quite > larger than human brains. While social and intelligent > animals, they're certainly not more intelligent than human > beings. Perhaps the absolute size of a certain section > of the brain? Like the cerebellum? I don't know enough > about elephant anatomy to say whether or not one part of > an elephant brain is larger than another part. Actually, > my instinct tells me that there is some sort of minimum > constant k=c*s, where s is size and c is connectivity (i.e. > number of neural connections per brain cell)... so that > creatures with smaller brains could still be intelligent if > they had a higher density of connections. Well, > actually, another possibility is that there is simply a minimum > number of connections... Yeah, Its assumed that you need a minimum size to have enough cells, for enough interconnections, to get a complex enough brain; But you also need a big enough brain to body ration so the brain has enough excess power to spare on complexity. Dolphin Brains are bigger in size and ratio than human brains. But human brains use a larger fraction (10%) on intelegence. Dolphins sonar cortex is as large as the human visual cortex (30% of human brain), so even though the intelegence centers are far smaller, the total brain is larger. > Re: rddesign@wolfenet.com (Ric & Denisse Hedman) > > >>Well it takes 10,000 to operate an aircraft carrer, and far more than that to > >>maintain it. Add in other professions to maintain the entire civilization > >>needed to support them, and you get millions. > > > >Are there 10,000 people on one single "boat"? > >There are only 100-200 people needed to operate a submarine and they are > >able to live more than 1 year isolated from the outside world. > > The average Aircraft Carrier today has a crew of around 5000. I'm not sure > of the number but about 1/2 are there to take care of the planes and fly > them. 1/2 of the other 1/2 are there to maintain the systems to launch and > retrieve the planes. The rest run the ship. During Viet Nam some carrier had > up to 8000 crew. Opps. I knew Carrier crews were half for the ship, and half for the flight wing. But I couldn't remember if it was 5000 total, or by section. After I sent the E-mail I started to wounder about 10,000 > Re: hous0042@maroon.tc.umn.edu (Kevin C Houston) > > On Sun, 28 Jan 1996, Timothy van der Linden wrote: > > > ReplyTo: Kelly > > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to > > >maintain it. Add in other professions to maintain the entire civilization > > >needed to support them, and you get millions. > > How many of those are actually maintaining the boat, and how many are > training to use the weapons that boat is carrying. ---- No, they generally train crews before they send them out. Fewer ships sink that way. ;) > -----you keep bringing up > the military model Kelly, Are you assuming we are going to have to fight > someone/thing. I'll say again, the military is a bad example, many of > the people are engaged in specialized activity which has nothing to do > with the maintainance of the boat. Another large part of the crew is > engaged in activity to repair any damage that the enemy will inflict on > them. both groups would not be needed in a star-ship (given the fact > that we have written off weapon systems as unescessary, our only defense > upon meeting a hostile ship would be to surrender or self-destruct) I still think the military systems are the best example we have. Certianly the starship will be acting like an aircraft carrier. (Yes a large fraction of the starships crew will be engaged in specialize jobs not related to maintaining the ship. Otherwise why send them?) Also only the military operates large numbers of specialized people, in extreamly isolated, hostile/toxic areas, and gets them out again alive. Also they have done a goodly fraction of the exploration of this planet. I'm not saying we need the ship organized along military ranks, but our equipment will probably be much more like military gear, than anything else. Heavy, tough, built to operate in extreamly bad areas with little civilized infastructure to support them. Some of the equipment may very well be derived from military equipment. (Who else will have decades of bio-warfare experence in their systems designs?) Oh, the starship woun't be armed (though with the power of its engines and interstellar laser com, that might be a debatable point!), the landers and rovers would be armed and armored. I was talking about making sure the equipment could handel an attack by a pack of Tyronasaurus Rex's, and no one seemed to object. > > > >> My misunderstanding, but can food be kept for 20 years? > > > > > >Sure. We kept some cold war rations around for that long without > > >refrigeration. With high tech, you can keep normal foods almost indefinatly. > > > (Give or take a few problematic fruits like apples.) > > > > OK, indefinatly, so a humble 60 years would be possible for a single way > > mission :) > > Even if we can keep such foods, my carrots example shows that it's > cheaper in both mass and space to grow many foods rather than carry them . I did a detailed breakdown of groceries per 20 years vs a selfsustaining farm and found the break even point was 20-30 years (depending). I CAN'T FIND IT!! Its probably in the LIT Newsletters, so if Dave finishes the search engine I can find it that way. Or I might figure out where I put it on my hard drive. Anyway I'll forward that when I can find it. > >> >In a world without photosyntisis the non-oxegen forms could still dominate. > > you could have photosynthesis, without having oxygen. in our system, > plants break down water into hydrogen and oxygen, the hydrogen is tacked > onto a CO2 subunit, and then built up into carbo-hydrates. It is no > large stretch of the imagination to envision a system where the [Plants] > break down H2S and release S2 into the atmosphere tacking the hydrogen > onto a CO2 etc etc Interesting. I hadn't thought of that. I had though of fully chemosynthesis based ecologies like we have here in the deep ocean. But never a different type of photosynthesis. > > (By the way I couldn't find the meaning of "chavanist", are you sure you > > spelled it right? (I've an idea of the meaning though)) Sorry, I keep forgeting you don't always now informal english. > > About Dolphins, they are a species that went back to the sea after living on > > land, they are also air-breathing. ---- snip > > ----- even the lowly prairie dog has a > rudimentary language. It is sophisticated enough to convey the following > warnings ---- > In short, the prairie dogs gave different vocalizations when a dog, or a > human approached the nest, and gave different vocalizations when the same > man wearing different colored jacket walked through. they also gave some > indication what the direction of approach was. When a man walked in from > the North, the voalizations were recorded, and played back several days > later. every member of the prairie dog nest looked, not at the speakers, > but to the north. and when Hawk warnings are recorded and played back, > they all look to the sky Woah?! Neat. I knew a lot of animals and insects had language (certainly my dog demonstrates that effectivly) but I never heard of the prarie dog tests. > > RE: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > > > ReplyTo: Kelly > > >> Of the total budget spend by companies. You said only 5% was used for R&D, I > >> say about 80% is used by getting the raw materials. Here on Earth those raw > >> materials are difficult to obtain, in space it may be much easier (just > >> scoop the surface) and thus less manpower is needed. > > > >Most industries don't spend 80% on raw material (probably more like 10% - > >30%) the bulk is in labor costs. So automation will have a big effect. > > OK, I'm wrong. But I don't understand how you can say that automation > will decrease the cost dramatically, since you are saying that > automats need a lot of maintenance and take a lot of efford to build. So do people. Automation allows a few skilled people to do the work of a larger number of people without automation. It does not allow the automation system to work by itself without people. As long as their are people to fix and operate it, automate systems will work well and productivly. Which is why all large manufacturing industries use them. > >> Like a hairdresser, shoemaker, tailor, dentist, doctor, cook? Are these the > >> jobs you mean? > >> I wonder if we can come up with more than 100 or 1000 completely different > >> jobs that are needed in a starship. > > > >Well it takes 10,000 to operate an aircraft carrer, and far more than that to > >maintain it. Add in other professions to maintain the entire civilization > >needed to support them, and you get millions. > > Are there 10,000 people on one single "boat"? Ok, 5000. > There are only 100-200 people needed to operate a submarine and they are > able to live more than 1 year isolated from the outside world. Submarines are much simpler than carriers, and they seldom operate more than 3 months without coming into port. Actually I can't think of one ever going a year submurged? (RICK!! ??) > >> On the bottom of the sea, I can imagine, but in a high radiative field is > >> hard to believe, the DNA would be mutated beyond repair within seconds. Can > >> you recall the source? > > > >Several sources. Its an old story of some interest. Last I remember for > >sure was Science. They were studing the cell repair mecanisms that allow the > >bacteria they were studying to repair their genetic and tissua damage that > >fast. (No not in secounds!) They were fairly sure it developed to allow the > >bacteria to repair themselves fast enough to survive high temperatures, and > >woundered if it could be transfered to humans. I think they said the cell > >repair rates were high enough to allow the bacteria to survive thousands of > >times the human fatal radiation dosage. (Effectivly the radiation couldn't > >kill them untill it physically cooked them!) > > 100 Times, I can believe, even cockroaches can survive that (Of course they > have a better armour than bacteria). Now I only wonder how radiation levels > can be that low in reactors. I guess these bacteria had found a well > shielded place behind some bolds. No, the bacteria remained directly exposed to the radiation. The only shielding would be the cooling water batween them and the reactor core. > >The latest NASA reports say differently. The Magelin probe showed the > >thinner crust during its radar scans. > > It may be thin, I wasn't arguing that (It's no wonder if the surface > temperature is 450 degree Celcius, the cooling down of the core is much slower). > All I said was that most of the higher temperature was due to the greenhous > effect. Sorry, no the greenhouse effect is considered a dabatable effect at all, even on earth. > >> There are is a lot of dust and posionous gasses, which create a very dense > >> atmosphere (90 bar). This dense atmosphere full of greenhouse gasses (much > >> worse than CO2) and the higher radiation level are the main reasons for the > >> higher surface temperature. > > > >Given the debacle about greenhouse effect predictions on earth I'm cynical > >about predictions on alien worlds. > > Forget the predictions, it is proven than several gasses like CO2 and SO2 > have very well insulating properties. So the fact that these gasses are > present in abundance on Venus means that a greenhouse-effect is > responsable for the high temperature. No it doesn't, it just meen their are insulating gases in the air. It doesn't even tell you if they are keeping heat in, or out. > >Also its generally agreed that if earth > >was where Venus is, it would not become dramatically hotter. (Well not as > >dramatic as Venus. You could still live here. But you'll want to move north > >a bit. ;) ) > > Yes, but that is because Earth has a biosphere. If Earth had to do without > that and it would be moved to the place of Venus, then is would heat up and > once the greenhouse-effect took over there wouldn't be a way back. No, earth biosphere trims its temperature a bit, but not by hundreds of degrees! If that were true Earth would have been unable to ever evolve life. > >Unless you sell or to the developed world like the third world does. Expect > >them to scream as their economies fold. > > Maybe it's time for them to get their own economies... True, but screeming and blaming others is so much easier. > >> My misunderstanding, but can food be kept for 20 years? > > > >Sure. We kept some cold war rations around for that long without > >refrigeration. With high tech, you can keep normal foods almost indefinatly. > > (Give or take a few problematic fruits like apples.) > > OK, indefinatly, so a humble 60 years would be possible for a single way > mission :) Well, you wouldn't starve anyway. > >> Why have these organisms never evolved beyond a single cell? > >> And if they did as you suggest, why did they change to use oxigen? > > > >Algae poluted the atmosphere with so much oxegen everything was killed off. > > To survive the remaining life forms had to adapt to oxegen or avoid oxegen > >rich areas (its hard to evolve multi celular when you in those little > >enclaves.). Even now our cell nucleus is destroyed by oxegen contamination. > > But we do the best we can. ;) > > Oh, I thought you were referring to those bacteria living near sea-vulcanos. Some are there, or in stagnent pools (like parts of SanFransico bay) that have little or no oxegen. But no large ecologies can develop in such isolation. > >In a world without photosyntisis the non-oxegen forms could still dominate. > > How? If they used chemicals for their energy, then the supply of those > chemicals better be almost infinite. Most of the chemicals that organisms > use these days are recycled by using photosyntesis. Only a small fraction of > chemicals is freed by vulcanos, hardly enough to sustain a group of lifeforms. Depends on the planets and its chemistry. > >We were preditors before we had brains. Our ability to track game, and run > >for extreamly long distences without tiring, are our bigest adaptation for > >hunting. Thou naturally we wouldn't be nearly as good at it without our > >inteligence. > > No, we were apes before we had big brains, and apes are not preditors. We evolved from chimps, which are predators. (Unlike Gorillas.) Those chimps evolved (after some odd twists) into plains preditors and scavengers. We developed that (and primative tool making), before our brains expanded much. > (I never said that intelligent live could not come from wolves, but if it > would they need to change their claws first) They could develop intelegence. A need for that just mean you have complex problem between you and a steed meal. Wolve greatest problem toward developing intelegence is that they are to good at what they do. Racoons or Otters would be a better bet. They depend more on cleverness, and use hands and some (unfashioned) tools. > >> ---- Imagine you have a hand with a thumb and a > >> single finger, that would mean a serious handycap all things you could > >> normally do, would not be able or very hard, even many years after you had > >> become customed to it. (And we don't have a solid finger like crabs do) > > > >But what if you had 6 claw/hands like crabs doi? In general our hands are > >very good for what we use them for, but their are many alternatives with > >stregths and weakness over ours. Ours is not the only design that would > >work, or even the best of all possible hands (we've tested robots with > >better). > > Crabs have 8 legs and 2 claws (or scissors) the legs are made for walking > (and that's just what they do ;) ). They have about 6 - 8 claws, but the inner ones are very small and specialized for tearing down food for the mouth. > A larger brain needs a larger body, larger bodies need larger legs. Having > more than 4 legs will mean a disadvantage because of the extra weight. > Even if they had more legs they probably couldn't miss more than 2 of them > to permanently free them for hands. > > Also it would be unlikely that animals that stand on 4 legs would have only > a stump to stand on. Having a few small extremeties at each leg gives much > more stability. > > So while there are creatures with more than 4 legs, they aren't likely to > support a big brain. > That leaves only 2 legs to support the hands. If these 2 hands want to do > anything constructive, they better have more than 2 fingers. ???!! You have some strange and unsupported assumptions there. MOst of earths walking life forms have more than 4 legs. Almost all of the rest have 4. Given that humans are fairly small as animals go, I can't see any justification in assuming large 4 or six limbed creatures are impossible. Hell we have predatores in north america that are almost a ton! > I also wonder if creatures with gills (using oxigen in the water) could have > a large brain. In the water you would need very large gills to get enough > oxigen for that brain. Only very large underwater animals could have a big > brain, but what would the advantage be for them? They already are at the top > of the food-chain. Gills in water actually need les body mass than lungs in air. > >> So while an organism gets some usefull "hands" it also gets a smarter brain > >> to use that "hand". Once the brain gets bigger it may be usefull for other > >> purposes too, like better perception, better remembering, better learning. > > > >Most of our enlarged brain isn't devoted to our hands. Dolphins brains are > >even larger (proportionally) than ours. (Thou they are not evolved for > >inteligence.) We are not the only model the universe could use. > > Indeed, most of our brain isn't devoted to anything as far as we know. -- Actually we do know what all the centers of the brain do, just not how they do it. > --- I > meant that a large part is devoted to what you can do with your hands. > Suppose you have a large brain, but no hands/legs to make use of it. There > would not be any advantage then to have a bigger brain, so it would not evolve. The biggest section of the human brain evolved to use the eyes, not hands. Niether are used in itelegence, that evolved separatly. Kelly From popserver Tue Jan 30 05:42:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5210" "Tue" "30" "January" "1996" "00:12:42" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "110" "Re: Recycling/AI and super human computers" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA27864 for ; Mon, 29 Jan 1996 21:13:16 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id AAA22441; Tue, 30 Jan 1996 00:12:42 -0500 Message-ID: <960130001241_209768586@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Tue, 30 Jan 1996 00:12:42 -0500 RE: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > > Reply to Kelly: > > >Current indications are that it will accelerate. Given that we are assuming > >a large space infastructure to build the ship, that would give us all access > >to VAST raw material resouces and wealth. > > Growth is not necessary acceleration, besides that the gain for the public > is not always that much. Since the arrival of the televisions, they haven't > changed significantly: 30 years ago there was color tv and now they still > is. It's a bit more rectangular and has a little bit more quality but those > are no real gains. Medical care has grown about as fast as technology but > now that we have removed a lot of diseases, it is not growing that fast. > Maybe there will come a new acceleration after the genome project, but after > a while that will slow down too. > All in all, it will become harder and harder to find new bases to accelerate > from and after a while (few centuries) most will not accelerate anymore. ???!! TV's have changed dramatically in the last thirty years. Not the picture format, which is fixed by law, but the image clarity and relyability is far better. That of course ignores the fact that current TV's are about to be phased out for digital HDTV's (at least in the states). Medical gains are also accelerating, not declining. Infectious deseases unfortunatly are also ready for a comback. Virtually all major feilds from industrial architecture, computers, industrial manufacture, chemistry, aviation, farming, have all seen dramatic improvements. Theses improvements don't always do something obvious, but they are there. > >> Again, it depends on the gain. These days, many people decide to live from > >> social finances and not to work and earn more money. > > > >True but the welfare is so generous (if you don't mind sucking up to a > >burecrate dweeb) that the people on welfare (generally lower inteligence and > >education) would be hard pressed to find a better paying job. > > What happens if the jobs available are to difficult for less > intelligent people. After a while machines and AI will take > over a lot of work. And if AI really become smarter than we > are, then all the work we do would be superfluous. If the less intelegent can't find any job left at their skill level (or atleast not enough for all), they will eiather have to improve their abilities, or expect to be droped out of society. Sooner or later people get feed up with others living off them for no good reason. As for us and super intelegent AI's. Eiather we'll find something to do together (or co-evolve), or they will move on and ignore us. (We can hardly expect them to take care of us forever.) > >> I remember that the human brain has E20 neurons. But it is not especially > >> the memory but the the connection between them, all have to be parallel. > > > >The latest issue of ANALOG science fact/science fiction has an artical on > >current and future computer and nano-tech systems. We alread have built > >computers with more processing power, data flow, and memory capacity then the > >human brain. (As long as the total data flow rate is as great with a > >non-paralell system, it will work. Now if we could just tell it what to do!) > > In 20-30 years a 1 human equivelent system should cost what a good home > >computer costs now. Should help A.I. research quite a bit. ;) > > I find it hard to believe, the GRAY C916 computer has a memory of 16Gb and a > computing speed of 16 GFLOPSs. Its I/O bandwith is 13.6 Gb/sec. > (It uses a maximum of 3.5E5 Watt, not something you want in your house) > The amount of bytes is many orders smaller than the amount of neurons of a > human brain (assuming a neuron has about 256 states). As you can see, the > GRAY can recall all it's memory in about 1 sec, but than it doesn't do any > calculations, which are necessary to make any sense in a neural-network. > > Further more a few years ago the biggest neural network was 1E5 neurons and > they had a hard time of getting them to work together. A fly has a brain of > 1E12 neurons (hope I'm right) so it's a long (but not impossible) way to > human AI. > > Timothy Its Cray not Gray. Best current bet is that the human brain has E10 Neurons and can process the equivelent of E14 bits per second. Rough guess at computing power 1 teraflop (one trillion floating point calculations per secound). The biggest computer I know of personally is a 4-5 tera byte (E12 byte system) being constructed in my old neighborhood in Reston Virgina for the phone companies cable TV experement. The Cray corporation is building a 9 teraflop system for the US government DARPA research agency (completion scheduled for 1998), and their competitor (thinking machines) is offering a 2 teraflop system comercially for $100 million. So we already are building systems bigger and more powerfull than the human brain, we just don't really know how to make them think. True intelegence may require custom circutry. But that circutry could be built in a way similar to the current circuts. If of course it does need couston circuts, which is hotly debated. Kelly From popserver Tue Jan 30 07:15:05 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3966" "Tue" "30" "January" "1996" "08:13:57" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "86" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id XAA05891 for ; Mon, 29 Jan 1996 23:12:27 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA04067 (5.67b/IDA-1.5 for ); Tue, 30 Jan 1996 08:13:46 +0100 Message-Id: <199601300713.AA04067@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Tue, 30 Jan 1996 08:13:57 +0100 To Kevin: >Even if we can keep such foods, my carrots example shows that it's >cheaper in both mass and space to grow many foods rather than carry them . Yes, I had not forgotten that :) >>In a world without photosyntisis the non-oxegen forms could still dominate. > >you could have photosynthesis, without having oxygen. in our system, >plants break down water into hydrogen and oxygen, the hydrogen is tacked >onto a CO2 subunit, and then built up into carbo-hydrates. It is no >large stretch of the imagination to envision a system where the [Plants] >break down H2S and release S2 into the atmosphere tacking the hydrogen >onto a CO2 etc etc Yes, I almost assumed directly that photosynthesis was used as we know it best. 6H20 + 6CO2 + energy --> C6H12O6 + 6O2 6H2S + 6CO2 + energy --> X + 6S2 where X=C6H12S6 ? To break down H20 takes much more energy than needed for H2S. 2.86/0.201=14.2 times more to be exact. But the other way around: Organisms using S2 get much less energy while using it as an oxidator. Also I'm not sure what X should be, C6H12S6 probably doesn't exist. Maybe all Sulphur is formed to S2 while leaving CnHn which could react to S2 but how well? So to be short S2 levels should be 14 times higher than oxigen levels or the organisms must have bigger "lungs". Finally, I'm not sure about the distribution of chemicals in planets, but often there is a lot of reacted oxigen present (SO2 CO2 H2SO4 etc.) When oxigen is present it will react to the S2 and that means again a loss of energy per Sulphur-atom. >Kevin speaks: >chauvinist -- one who has a prefrence for a particular group of which he >is a member. applied to gender, to would mean a man who thought that it >is better to be a man than a woman, not really one who thinks that men >are better than women, just one who thinks it is better to be a man. It >is a milder form of racism. I don't think that is what Kelly means, I figured it meant something like some one who likes to cut off fingers and limbs, but as said before I can't find a dictionary to confirm that. >> About Dolphins, they are a species that went back to the sea after living on >> land, they are also air-breathing. So that may explain some of the size of >> the brain. >> You said proportionally, but for intelligence only the absolute size is >> impotant. Besides that, dolphins are almost the same size we are. So if they >> have big brains, they have to use them somehow otherwise it would be a bad >> evolutionary design which is unlikely. I really wonder what a "fish" could > >there is some evidence that dolphins devote a large portion of their >brains to sonar image processing. and perhaps even language. as to >absolute size, that is not true. I'm not sure, what you mean regarding absolute size of the brain. To prove that the absolute size doesn't matter, you say that prairy dogs with a lot smaller brain than ours are less smart than we are. To me this seems like prove for the opposite: A certain absolute size is needed to become intelligent the way we know it. By the way, I saw a serie on the television where some other animals did exactly the same. I'm not sure how these animals were called, but they lived in hills and always stood on their back legs looking being on watch. Timothy ========================================================================== >in fact, I would say that _any_ carbon based life could be killed with >the proper chemicals (and leave us unharmed,) the Question is how long >would it take for us to find the proper chemicals? I also never doubted that, neither did Kelly, but we all don't know for sure what it takes to kill them. What a goal... we go to a planet and first thing we do is try to kill the live that's living there. >Kevin (to whom 1E18 Watts of maser energy sounds really good right now) What is it that are you engineering? 1E18 still sounds awfull to me. Tim P.S. Quantum physics is still coming... From popserver Wed Jan 31 04:29:54 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1648" "Tue" "30" "January" "1996" "17:02:59" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "27" "Newsletter" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA25167 for ; Tue, 30 Jan 1996 17:01:22 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts1-p44.wolfenet.com [204.157.98.98]) by wolfe.net (8.7.3/8.7) with SMTP id RAA00847; Tue, 30 Jan 1996 17:02:59 -0800 (PST) Message-Id: <199601310102.RAA00847@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Newsletter Date: Tue, 30 Jan 1996 17:02:59 -0800 (PST) >> There are only 100-200 people needed to operate a submarine and they are >> able to live more than 1 year isolated from the outside world. >Submarines are much simpler than carriers, and they seldom operate more than >3 months without coming into port. Actually I can't think of one ever going >a year submurged? (RICK!! ??) OK, guys. Here is what I know. The USS Triton, ( The only 2 reactor US submarine) Sailed around the world submerged. They did have to come to a "deck awash" situation what an ill crew member had to be airlifted off) So, 26,000 miles submerged. The boat I was on, (USS Flasher, SS(N)613) was operated on two month cruises although we carried food for 140 days. I understand todays boats do 3 month cruises. We suffered from "big eye" during our trips. This means that after a month or so we were slept out. Had read the majority of the books brought aboard and has seen all the GOOD movies we took with us. Knowing we were to enter port in 2 to 3 weeks made the crew antsy and wanting to see family members again. Cleaning up the for entering port took a fair amount of time also. Usually was deligation from ComSubPac would come aboard as soon as we docked so the Capt. and XO wanted the place pretty. I'm sure the present day crews go through the same processes. Even at 600' todays boats, most is missile compartment, still don't have enough privete spaces for much longer time periods. Crews are about 250, mine was 113 in a 292' hull. If the 300' of missile compartment was converted into rec areas, private rooms. movie theaters. you could possibly have a crew of 300 or so the could do a year underwater. Ric From popserver Wed Jan 31 09:25:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1382" "Wed" "31" "January" "1996" "10:23:17" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "37" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA27469 for ; Wed, 31 Jan 1996 01:21:53 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28539 (5.67b/IDA-1.5 for ); Wed, 31 Jan 1996 10:23:04 +0100 Message-Id: <199601310923.AA28539@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Wed, 31 Jan 1996 10:23:17 +0100 To David: >I would disagree that only absolute size is important. I'm >not positive, but I'm assuming elephant brains are quite >larger than human brains. Yes, you are right, I always thought different, but today I did some research and found that indeed dolphin and elephant brains are bigger. >While social and intelligent >animals, they're certainly not more intelligent than human >beings. Perhaps the absolute size of a certain section >of the brain? Like the cerebellum? I think you mean cerebrum (the large brains). >I don't know enough >about elephant anatomy to say whether or not one part of >an elephant brain is larger than another part. I'm not sure either anymore, but think that indeed the absolute size of the different kinds of the brain is important. Like Kelly wrote, doplhins have a large part of their brain devoted to sonar and communication and probably less to the eyes. >Actually, >my instinct tells me that there is some sort of minimum >constant k=c*s, where s is size and c is connectivity (i.e. >number of neural connections per brain cell)... so that >creatures with smaller brains could still be intelligent if >they had a higher density of connections. Well, >actually, another possibility is that there is simply a minimum >number of connections... I think connectiveness depends on the function of a certain part of the brain. Timothy From popserver Wed Jan 31 09:25:33 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4321" "Wed" "31" "January" "1996" "10:23:35" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "86" "Re: Recycling/AI and super human computers" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA27479 for ; Wed, 31 Jan 1996 01:22:02 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28562 (5.67b/IDA-1.5 for ); Wed, 31 Jan 1996 10:23:23 +0100 Message-Id: <199601310923.AA28562@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Wed, 31 Jan 1996 10:23:35 +0100 Reply to Kelly: >???!! TV's have changed dramatically in the last thirty years. Not the >picture format, which is fixed by law, but the image clarity and relyability >is far better. That of course ignores the fact that current TV's are about >to be phased out for digital HDTV's (at least in the states). Yes, but untill HDTV (which is more or less the logical step to digital multi media and communication) these improvements are not so big that every living soul (overstatement) wants to buy a new television. In fact the step to HDTV has to push a lot of unwilling people buying new TV's (unless their old ones breaks down beyond repair.) Is the advantage of the Hifi audio and video (probably compressed with MPEG (which hopefully is better than what I see on my P5)) indeed that big that all people WANT to buy it? My guess is that only new purposes like interactive TV, pay-TV, internet by TV will tempt many people to buy such an apparatus. >Medical gains are also accelerating, not declining. Infectious deseases >unfortunatly are also ready for a comback. Yes, I read that that was because most the bacteria become resitant and because the pharmaceutic industry forgot that area but are now heading for a come back. >Virtually all major feilds from industrial architecture, computers, >industrial manufacture, chemistry, aviation, farming, have all seen dramatic >improvements. Theses improvements don't always do something obvious, but >they are there. But are these advancements accelerations or just steady growth? >> What happens if the jobs available are to difficult for less >> intelligent people. After a while machines and AI will take >> over a lot of work. And if AI really become smarter than we >> are, then all the work we do would be superfluous. > >If the less intelegent can't find any job left at their skill level (or >atleast not enough for all), they will eiather have to improve their >abilities, or expect to be droped out of society. Sooner or later people get >feed up with others living off them for no good reason. Rethinking it, I come to the conclusion that as soon as AI has an IQ of 80 it will only take a few years to reach 180. >As for us and super intelegent AI's. Eiather we'll find something to do >together (or co-evolve), or they will move on and ignore us. (We can hardly >expect them to take care of us forever.) Maybe we should make them just smart enough to do the dirty jobs. And use only a few with IQ 1000 to think. Now we just have to hope they don't interconnect without us noticing. Another possibility is to let them learn a while and then freeze the learning capability. That would be like you were stuck at a certain age, able to some specific job that needed little or no adjustment. >Best current bet is that the human brain has E10 Neurons and can process the >equivelent of E14 bits per second. Rough guess at computing power 1 teraflop >(one trillion floating point calculations per secound). Yes, I found a single reference (after looking through 20 books about AI) that confirmed your E10 (and not my E20) of information units (meaning neurons*connections?). >The biggest computer I know of personally is a 4-5 tera byte (E12 byte >system) being constructed in my old neighborhood in Reston Virgina for the >phone companies cable TV experement. The Cray corporation is building a 9 >teraflop system for the US government DARPA research agency (completion >scheduled for 1998), and their competitor (thinking machines) is offering a 2 >teraflop system comercially for $100 million. Yes, I found some info about another CRAY having max 1.2 TFLOPS. >So we already are building systems bigger and more powerfull than the human >brain, we just don't really know how to make them think. True intelegence >may require custom circutry. But that circutry could be built in a way >similar to the current circuts. If of course it does need couston circuts, >which is hotly debated. Custom circuis are is less efficient to do highly parallel computing than neural-circuits. So once the parallel computing is better controlled or once the neural-activity is better understood the whole circuits will become much more efficient. Of course non-chaotic system may always be more efficient on less parallel circuits. Timothy From popserver Wed Jan 31 09:25:35 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10812" "Wed" "31" "January" "1996" "10:23:23" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "225" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA27485 for ; Wed, 31 Jan 1996 01:22:07 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28546 (5.67b/IDA-1.5 for ); Wed, 31 Jan 1996 10:23:10 +0100 Message-Id: <199601310923.AA28546@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Wed, 31 Jan 1996 10:23:23 +0100 To Kelly: >Yeah, Its assumed that you need a minimum size to have enough cells, for >enough interconnections, to get a complex enough brain; But you also need a >big enough brain to body ration so the brain has enough excess power to spare >on complexity. But why do elephants have such big brains (3 to 4 times larger than humans)? >Dolphin Brains are bigger in size and ratio than human brains. But human >brains use a larger fraction (10%) on intelegence. Dolphins sonar cortex is >as large as the human visual cortex (30% of human brain), so even though the >intelegence centers are far smaller, the total brain is larger. >I did a detailed breakdown of groceries per 20 years vs a selfsustaining farm >and found the break even point was 20-30 years (depending). I CAN'T FIND >IT!! Its probably in the LIT Newsletters, so if Dave finishes the search >engine I can find it that way. Or I might figure out where I put it on my >hard drive. Anyway I'll forward that when I can find it. I've some 1.6 Meg of old newsletters (Older than miniLIT). If you know some keywords, I can search them for you. >Automation allows a few skilled people to do the work of a larger number of >people without automation. It does not allow the automation system to work >by itself without people. As long as their are people to fix and operate it, >automate systems will work well and productivly. Which is why all large >manufacturing industries use them. But that means that much less people can do the job >> There are only 100-200 people needed to operate a submarine and they are >> able to live more than 1 year isolated from the outside world. > >Submarines are much simpler than carriers, and they seldom operate more than >3 months without coming into port. Actually I can't think of one ever going >a year submurged? (RICK!! ??) As far as I know they only come to the surface to recalibrate the navigation systems. They even don't communicate with the home base so that their exact position isn't known (They do receive messages though, but don't answer) I've heard they sometimes don't harbour for more than a year, this of course depends on the size of the submarine. (The largest Russian sub even has a small swimming pool!) >> 100 Times, I can believe, even cockroaches can survive that (Of course they >> have a better armour than bacteria). Now I only wonder how radiation levels >> can be that low in reactors. I guess these bacteria had found a well >> shielded place behind some bolds. > >No, the bacteria remained directly exposed to the radiation. The only >shielding would be the cooling water batween them and the reactor core. But then they must be exposed to maybe 1 million times the deadly radiation, I really have to find that article... >> Forget the predictions, it is proven than several gasses like CO2 and SO2 >> have very well insulating properties. So the fact that these gasses are >> present in abundance on Venus means that a greenhouse-effect is >> responsable for the high temperature. > >No it doesn't, it just meen their are insulating gases in the air. It >doesn't even tell you if they are keeping heat in, or out. It's keeping the heat in: Greenhouse gasses are more opaque planetary radiation than for solar radiation. Solar radiation is what directly comes from the Sun and planetary radiation is what is reflected from the planet's surface. When solar radiation hits the surface of the planet, the main part is absorbed, after a while the soil heats up and start radiating but this is largely infra-red radiation while the incoming radiation had more shorter wavelengths. As for the debacle about Earth's greenhouse effect, there are only doubts about the quantity of the temperature increase caused by the greenhouse gasses. Also it is argued if the greenhouse gasses are the only reason for temperature increase. >> Yes, but that is because Earth has a biosphere. If Earth had to do without >> that and it would be moved to the place of Venus, then is would heat up and >> once the greenhouse-effect took over there wouldn't be a way back. > >No, earth biosphere trims its temperature a bit, but not by hundreds of >degrees! If that were true Earth would have been unable to ever evolve life. To that I agree, but as long the greenhouse effect is not too large the temperatures will not become so high that no live can exist. At the light-side of the moon you will freeze to death (assuming you weren't choking first) this is because there are no gasses to keep the heat in. The only heat there is radiative heat. >> OK, indefinatly, so a humble 60 years would be possible for a single way >> mission :) > >Well, you wouldn't starve anyway. The Dutch word "sterven" means to die. For "to starve" we use a completely different word: "verhongeren" ("go hungry" is what comes nearest) >> Oh, I thought you were referring to those bacteria living near >sea-vulcanos. > >Some are there, or in stagnent pools (like parts of SanFransico bay) that >have little or no oxegen. But no large ecologies can develop in such >isolation. Indeed, so the chances for much evolution are also limited. >>>In a world without photosyntisis the non-oxegen forms could still >>>dominate. >> >> How? If they used chemicals for their energy, then the supply of those >> chemicals better be almost infinite. Most of the chemicals that organisms >> use these days are recycled by using photosyntesis. Only a small fraction >>of chemicals is freed by vulcanos, hardly enough to sustain a group of >>lifeforms. > >Depends on the planets and its chemistry. I think that if chemicals are not recycled any amount is used up in a relative short period. (If water and carbondioxide where not recycled by plants, animal (non photosynthesis) live would very soon die away). >> No, we were apes before we had big brains, and apes are not preditors. > >We evolved from chimps, which are predators. (Unlike Gorillas.) Those >chimps evolved (after some odd twists) into plains preditors and scavengers. I've never heard that before, so I'm not certain. >We developed that (and primative tool making), before our brains expanded >much. I've seen a TV-series (again :) ) that tried to explain that the human brain expanded as soon as it began standing up. The reason for that was the temperature difference between 0.8 metre (on 4 legs) and 1.5 metres (on 2 legs) above the ground. In Africa where they assumed the first "humans" lived there first was a quite nice green landscape, but then relative sudden (10,000 years or so) a 1000 kilometre mountain ridge appeared in the middle of Africa, that had influence on the weather and at one side it became a rather dry prairie landscape with only a few bushes. The distance between those save bushes where rather large, so the apes living there has to move relative large distances (for apes which are not very good at walking). So after a while the started moving on 2 legs, which gave them more speed and thus more survival-chances because they had a larger area to feed from. Now it comes: Because the temperature at 1.5 meter was much lower (5 degrees or more, because of the wind etc.) than on 0.8 metre the brain could be cooled better and thus could now expand. So to be short: The apes had to walk on 2 legs to have better survival chances, then they got a cooler head and had the possibility to become a larger brain. One question remains however, why didn't they get a bigger brain while in the forest before the mountain ridge appeared? >They have about 6 - 8 claws, but the inner ones are very small and >specialized for tearing down food for the mouth. OK, but a crabs brain is just to small to become intelligent. >> A larger brain needs a larger body, larger bodies need larger legs. Having >> more than 4 legs will mean a disadvantage because of the extra weight. >> Even if they had more legs they probably couldn't miss more than 2 of them >> to permanently free them for hands. >> >> Also it would be unlikely that animals that stand on 4 legs would have only >> a stump to stand on. Having a few small extremeties at each leg gives much >> more stability. >> >> So while there are creatures with more than 4 legs, they aren't likely to >> support a big brain. >> That leaves only 2 legs to support the hands. If these 2 hands want to do >> anything constructive, they better have more than 2 fingers. > >???!! You have some strange and unsupported assumptions there. MOst of >earths walking life forms have more than 4 legs. Almost all of the rest have >4. Given that humans are fairly small as animals go, I can't see any >justification in assuming large 4 or six limbed creatures are impossible. > Hell we have predatores in north america that are almost a ton! - First I said that only larger animals could support a brain large enough to become intelligent. (I think a mouse-brain is too small) - Then, I said that more that 4 legs were a disadvantage for larger animals because of the extra weight. - After eliminating all creatures with more than 4 legs, I said that that 2 of those 4 legs had to be used for tool-making etc. >>I also wonder if creatures with gills (using oxigen in the water) could have >>a large brain. In the water you would need very large gills to get enough >>oxigen for that brain. Only very large underwater animals could have a big >>brain, but what would the advantage be for them? They already are at the top >> of the food-chain. > >Gills in water actually need les body mass than lungs in air. I think that's because fish need much less oxigen. One of the reasons is because they are cold-blooded. One of the biggest fish are sharks, but they have to swim (slowly) all the time to get enough oxigen ot of the water. >> Indeed, most of our brain isn't devoted to anything as far as we know. -- > >Actually we do know what all the centers of the brain do, just not how they >do it. Why have I heard so many times that 90% of the brain (or did they mean the cerebrum) is unused? >> --- I >> meant that a large part is devoted to what you can do with your hands. >> Suppose you have a large brain, but no hands/legs to make use of it. There >> would not be any advantage then to have a bigger brain, so it would not >>evolve. > >The biggest section of the human brain evolved to use the eyes, not hands. > Niether are used in itelegence, that evolved separatly. Yes, I'm slowly seeing that size is not the most important factor and that the largest part of the brain was and is already available. Could it be that the use of hands and its applications involved a completely new way of neuron interconnection which had intelligence as convenient side product? If I'm not right about this hands->brain connection, then why did we get a bigger brain? Timothy From popserver Wed Jan 31 17:50:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3502" "Wed" "31" "January" "1996" "08:40:37" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "65" "I found the food numbers!" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA05766 for ; Wed, 31 Jan 1996 05:41:37 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA04090; Wed, 31 Jan 96 08:43:13 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI003994; Wed Jan 31 08:41:20 1996 Received: by most (4.1/SMI-4.1) id AA02213; Wed, 31 Jan 96 08:41:18 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002201; Wed Jan 31 08:40:40 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA29023; Wed, 31 Jan 96 08:40:35 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: David@interworld.com (David Levine) Cc: Kelly Starks x7066 MS 10-39 , Kevin C Houston , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu Subject: I found the food numbers! Date: Wed, 31 Jan 1996 08:40:37 -0500 I found the analysis I did on food mass numbers!!! ============================================================================ Date 6/29/95 Subject Food Mass The farms discussed in the "Space Settlements: A design study" (the book I reference frequently, and STRONGLY recommend) lists the farm mass per person at about 36 tons of which 22 tons is soil. The farm includes everything from farm animals to fish, and all normal grains and vegetables. The idea was to make it capable of providing all normal food needed for a standard North American diet for a population of 10,000. Said diet according to their numbers weighed about 1.67 tons per-person per year. They also assumed that with intensive care this farm could produce twice the yield of the best farms on earth. Now we found that rations for field troops or explorers weighed about 2.2 kilos per day (.8 tons per year) and dehydrated could be a lot less. But over all; 36 tons per person is about 21 years of food mass at their 1.67 tons per year, or 45 food years at our .8 tons per year. I'm not even going to bother with freeze dried numbers. We won't want to be out that long! Even if you assume no soil. The mass is still 14 tons per person. Which comes to 8.38 year of 1.67 tons per year food years, or 17.5 years at our .8 tons per year. Then I realized that the farm design required doubling the internal volume of the hab centrifuge. Which would add another 20 to 230 tons per person! (the latter if you shielded the farm centrifuge.) Any way I ran it, the mass for a transportable, self sustaining farm, wound up greater than the stored food mass for the duration of our projected missions. Given that the stored mass would decline as the mission went on (on good thing for the return flight), stored food would be simpler and more reliable than trying to maintain a running farm during a mission, and the farm would almost double the size of the full g gravitation sections needed in the ship. I decided to dump the idea and assume ultra frozen and dried foods stored in the zero g section of the ship. We could have a couple gardens for fun and fresh Veggies, but I'd assume they were just a couple plants in the corner of peoples apartments. You might do an analysis to see if hydroponics for the vegies would weigh less than storing frozen veggies. I.E. we store the meat, flour, rice, milk, ect.., but grow the fruits and vegetables. But for my porpoises I assumed the mass numbers wouldn't show an advantage. Oh, while on the topic of Mass. The drive system people seem to be going through hoops to build a huge, high efficiency (relativistic exhaust) engine to keep the necessary reaction mass amounts down to grams per day. I would suggest that if we aren't going to recycle our -- ah-- food by products. The crew will be providing a few tons of usable mass per day. Dehydrate, incinerate to plasma or ionize, and pump it into the accelerator. With an electro-magnetic accelerator (as apposed to a thermal rocket) the type of mass used is unimportant, and for ship design purposes using the same stored mass to feed the crew and drive system is very elegant and efficient. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Wed Jan 31 17:51:15 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["844" "Wed" "31" "January" "1996" "09:26:10" "-0500" "David Levine" "David@interworld.com" nil "22" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id GAA07923 for ; Wed, 31 Jan 1996 06:25:30 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA309; Wed, 31 Jan 1996 09:30:37 -0500 Message-ID: <310F7C02.7269@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <199601310923.AA28539@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Wed, 31 Jan 1996 09:26:10 -0500 Timothy van der Linden wrote: > > To David: > >While social and intelligent > >animals, they're certainly not more intelligent than human > >beings. Perhaps the absolute size of a certain section > >of the brain? Like the cerebellum? > > I think you mean cerebrum (the large brains). Yup, thanks. Hey, all, I've just been contacted by the BBC via email about a television show they want to do this summer about how science fiction becomes science fact. I'm not sure they understand that LIT is a bunch of amateur starship designers, and not actual professors or anything. I'm not sure what to tell them. I've been thinking about just explaining the situation to them, explaining exactly what it is we're doing, and perhaps giving them email addresses of good people to contact whom I've met through LIT (like Zenon, if you'd want?)... From popserver Wed Jan 31 17:51:25 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1792" "Wed" "31" "January" "1996" "15:49:34" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "33" "Re: I found the food numbers!" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA11668 for ; Wed, 31 Jan 1996 07:36:46 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA07141 (5.67b/IDA-1.5); Wed, 31 Jan 1996 15:49:19 +0100 Message-Id: <199601311449.AA07141@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Wed, 31 Jan 1996 15:49:34 +0100 > Now we found that rations for field troops or explorers weighed about 2.2 >kilos per day (.8 tons per year) and dehydrated could be a lot less. But >over all; 36 tons per person is about 21 years of food mass at their 1.67 >tons per year, or 45 food years at our .8 tons per year. I'm not even >going to bother with freeze dried numbers. We won't want to be out that >long! Even if you assume no soil. The mass is still 14 tons per person. >Which comes to 8.38 year of 1.67 tons per year food years, or 17.5 years at >our .8 tons per year. Then I realized that the farm design required >doubling the internal volume of the hab centrifuge. Which would add another >20 to 230 tons per person! (the latter if you shielded the farm >centrifuge.) Would stored food need no protection against radiation? I'm not sure how much and if the food would become radioactive. But if it does, it may need shielding too. >Oh, while on the topic of Mass. The drive system people seem to be going >through hoops to build a huge, high efficiency (relativistic exhaust) >engine to keep the necessary reaction mass amounts down to grams per day. >I would suggest that if we aren't going to recycle our -- ah-- food by >products. The crew will be providing a few tons of usable mass per day. >Dehydrate, incinerate to plasma or ionize, and pump it into the >accelerator. With an electro-magnetic accelerator (as apposed to a thermal >rocket) the type of mass used is unimportant, and for ship design purposes >using the same stored mass to feed the crew and drive system is very >elegant and efficient. Using all these different kinds of atoms would not be very efficient and probably impossible. Accelerators work best if only one kind of particle (depending on mass & charge) is used. Timothy From popserver Wed Jan 31 17:51:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4562" "Wed" "31" "January" "1996" "15:36:10" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "92" "Re: Power!" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA12279 for ; Wed, 31 Jan 1996 07:47:12 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA05009 (5.67b/IDA-1.5); Wed, 31 Jan 1996 15:35:53 +0100 Message-Id: <199601311435.AA05009@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Power! Date: Wed, 31 Jan 1996 15:36:10 +0100 To: Brian Mansur . . . still there and thinking >I ran some calculations over Christmas and found that to produce 1E18 W, >which is what Kevin, and the rest of the solar system would like, requires >billions of square kilometers of solar arrays. The exact number depends on >collection/transmission efficiencies and, of course, the distance of the >collectors from the Sol. Since the total circular area of say Mercury is on >the order of mere millions of kilometers, even covering the planet with >solar panels is not going to produce close to 1E18 W. Indeed just use: Area needed for 1E18 watt solar power = (4 pi r^2)/4E10 r=distance to the Sun (This assumes 100% efficiency) For Mecury this means r=5.8E10 --> Area=1E12 m^2 The radius of Mercury is 2.433E6 metres thus its surface is 4*Pi*r^2 this gives a surface of 7.44E13 m^2. So the total surface of Mercury is 70 times bigger. Of course only one half can be illuminated at once so then the area is 35 times bigger than needed by 100% efficiency. >Since launching and recovering these arrays at the rates needed to keep up >E9's of panels at any given time seem to cost more power and resources than >we'd like, I suggest that we tether the panels to Mercury's poles. > >What?! Can't be done, you say? Well, probably, but we're grasping for >ideas here. > >Think about it. It would be like flying a kite on the solar wind. Since >Mercury does have some rotation relative to its revolution (it is not faced >locked with the sun like the moon is with Earth) we build superduper strong >suspension cables/towers/ whatever at the poles where we could perhaps >counter-rotate the cable anchors on a merrygoround to prevent them from >winding up as Mercury spins. That or we could put down many, many >individual connections to the surface that can be unlinked and reset to keep >(torquing is it?) to a minimum. I wonder what will be a bigger force, Mercuries gravity or the solar radiation pressure, this of course depends on the distance from Mercury. The cables you are talking about should indeed be very strong: m=mass of the cable g=Mercury gravity (3.58 m/s^2) F=force rho=density of the material of the cable (using Aluminium 2.6E3 kg/m^3) l=length of the cable A=Area of a cut through surface of the cable (depends on the tickness) T=Pull strength (in Pascal=N/m^2) F=m*g m=rho*l*A T=F/A --> T=rho*l*g So now we know the minimum pull strength needed for a cable of length l and a density rho in having a gravitional acceleration g. So assuming that gravity doesn't change much the first 1E6 metres: T=2.6E3*1E6*3.58=9.3E9 Pa The pull strength of aluminium is about 3E8 Pa thus such a long line will snap under its own weight. Of course I used a line that had the same thickness all along the line. It would be better if the line was thick at the bottom and thin high in the "air". So in these cases the weight of the cable is an important factor assuming that it is pulled upward enough (In the worst case the cable is so heavy that it will drag the whole solar-array down to Mercury.) Now that I think about it, I wonder if cables are needed. You could just keep the whole array floating in at a place where solar radiation pressure and the pull of Mercury are equal, then add some small engines to keep it there. I thought of this before but then not using Mercury but using the Sun itself to pull the array back, the problem thereby was that it probably had to be to close to the Sun, unless ofcourse it rotates around the Sun at just the right distance. The porblem that I see though is that any rotating solar-array is difficult to use, since the angles of incoming and outgoing radiation constantly change and don't equal each other, which causes an instable orbit. >As I said, I don't know if this will work because I realize that, even with >a lot of cables dividing the load of the pull by a collector the size of a >face of Jupiter, the tension will be incredible. Also there is Mercury's >gravitational attractions for the array and the cables to consider. I hope >someone can give some hope to this idea because I don't have the time or >skills to try to figure out the dynamics. An advantage to this idea, >however, would be that we could keep the array very close to a planet sized >solar panel service station. Oh, and another problem to consider is how the >mercury rises as one nears the orbit of Mercury. Radiation levels at Mercury are about 7 times higher, so it may be able to overcome the increase of temperature. Timothy From popserver Thu Feb 1 03:02:08 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2037" "Wed" "31" "January" "1996" "17:22:42" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "36" "Re: Hands and brains" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA00732 for ; Wed, 31 Jan 1996 17:21:20 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts1-p36.wolfenet.com [204.157.98.90]) by wolfe.net (8.7.3/8.7) with SMTP id RAA19722; Wed, 31 Jan 1996 17:22:42 -0800 (PST) Message-Id: <199602010122.RAA19722@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Hands and brains Date: Wed, 31 Jan 1996 17:22:42 -0800 (PST) > >>> There are only 100-200 people needed to operate a submarine and they are >>> able to live more than 1 year isolated from the outside world. >> >>Submarines are much simpler than carriers, and they seldom operate more than >>3 months without coming into port. Actually I can't think of one ever going >>a year submurged? (RICK!! ??) > >As far as I know they only come to the surface to recalibrate the navigation >systems. They even don't communicate with the home base so that their exact >position isn't known (They do receive messages though, but don't answer) >I've heard they sometimes don't harbour for more than a year, this of course >depends on the size of the submarine. (The largest Russian sub even has a >small swimming pool!) A Submarines Inertial Navigation System is calibrated before the boat ever goes on its' first seatrial. Any adjustments are done at that time. Any fine tuning later would prbably be done in a shipyard. Befxore the boat was commissioned the Nav System would have been signed off as a matter of course. In the whole time I was aboard we never had to adjust ours. To get a "satnav" fix you would have to put a parascope up, (they have a stack of antenas on the top of them,) and get your satalite fixes. Parascopes even have a sextent in them to do star and moon and sun sights from parascope depth. The Inertial Nav System works off of the gyro cumpuses, shaft speed, current speed and direction and course steared. In my day it was a computer the size of a refrigerator. I'm sure it is much smaller now. Submarines opperates as our starship will have to, no contact or very little contact with a home base. Operating oders are issued and opened after the boat has sailed. Each boat has its' own mission to perform and needs no contact to carry it out. Yes that Russin sub is a monster. :-) and from what I have heard about Russin subs the men deserve all the bennies they can get, The early Russian nukes were so "dirty" with radiation that the death rate from cancer was very high. Ric From popserver Thu Feb 1 03:02:16 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3543" "Wed" "31" "January" "1996" "17:28:02" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "63" "Re: I found the food numbers!" "^From:" nil nil "1" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA01210 for ; Wed, 31 Jan 1996 17:26:38 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts1-p36.wolfenet.com [204.157.98.90]) by wolfe.net (8.7.3/8.7) with SMTP id RAA20245; Wed, 31 Jan 1996 17:28:02 -0800 (PST) Message-Id: <199602010128.RAA20245@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: I found the food numbers! Date: Wed, 31 Jan 1996 17:28:02 -0800 (PST) >I found the analysis I did on food mass numbers!!! > > >============================================================================ > Date 6/29/95 Subject Food Mass > > >The farms discussed in the "Space Settlements: A design study" (the book I >reference frequently, and STRONGLY recommend) lists the farm mass per >person at about 36 tons of which 22 tons is soil. The farm includes >everything from farm animals to fish, and all normal grains and vegetables. >The idea was to make it capable of providing all normal food needed for a >standard North American diet for a population of 10,000. Said diet >according to their numbers weighed about 1.67 tons per-person per year. >They also assumed that with intensive care this farm could produce twice >the yield of the best farms on earth. > > Now we found that rations for field troops or explorers weighed about 2.2 >kilos per day (.8 tons per year) and dehydrated could be a lot less. But >over all; 36 tons per person is about 21 years of food mass at their 1.67 >tons per year, or 45 food years at our .8 tons per year. I'm not even >going to bother with freeze dried numbers. We won't want to be out that >long! Even if you assume no soil. The mass is still 14 tons per person. >Which comes to 8.38 year of 1.67 tons per year food years, or 17.5 years at >our .8 tons per year. Then I realized that the farm design required >doubling the internal volume of the hab centrifuge. Which would add another >20 to 230 tons per person! (the latter if you shielded the farm >centrifuge.) > >Any way I ran it, the mass for a transportable, self sustaining farm, wound >up greater than the stored food mass for the duration of our projected >missions. Given that the stored mass would decline as the mission went on >(on good thing for the return flight), stored food would be simpler and >more reliable than trying to maintain a running farm during a mission, and >the farm would almost double the size of the full g gravitation sections >needed in the ship. I decided to dump the idea and assume ultra frozen and >dried foods stored in the zero g section of the ship. We could have a >couple gardens for fun and fresh Veggies, but I'd assume they were just a >couple plants in the corner of peoples apartments. You might do an >analysis to see if hydroponics for the vegies would weigh less than storing >frozen veggies. I.E. we store the meat, flour, rice, milk, ect.., but grow >the fruits and vegetables. But for my porpoises I assumed the mass numbers >wouldn't show an advantage. > >Oh, while on the topic of Mass. The drive system people seem to be going >through hoops to build a huge, high efficiency (relativistic exhaust) >engine to keep the necessary reaction mass amounts down to grams per day. >I would suggest that if we aren't going to recycle our -- ah-- food by >products. The crew will be providing a few tons of usable mass per day. >Dehydrate, incinerate to plasma or ionize, and pump it into the >accelerator. With an electro-magnetic accelerator (as apposed to a thermal >rocket) the type of mass used is unimportant, and for ship design purposes >using the same stored mass to feed the crew and drive system is very >elegant and efficient. Reply to Kelly If we dump our "waste" into the fuel hopper we lose all that water that we are going to need unless you plan to squeeze all the water out first. I'm not adverse to putting unusable waste into the "fuel chain" for the ship but lets be sure we don't need it for other reasons first, please. Ric From popserver Thu Feb 1 16:35:21 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["22615" "Thu" "1" "February" "1996" "08:16:07" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "569" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA12376 for ; Thu, 1 Feb 1996 05:16:56 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA15474; Thu, 1 Feb 96 08:18:38 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI015393; Thu Feb 1 08:16:41 1996 Received: by most (4.1/SMI-4.1) id AA02720; Thu, 1 Feb 96 08:16:38 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002716; Thu Feb 1 08:16:08 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA06095; Thu, 1 Feb 96 08:16:04 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) Cc: Kevin C Houston , Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Re: Fwd: LIT e-mail discussion group Date: Thu, 1 Feb 1996 08:16:07 -0500 Ah, its been about a week since I sent out my draft summarry document (attached), and (other then Daves compliment) I haven't heard any responce to it. No one has any complaints, things they want added, changed etc? Kelly At 11:29 AM 1/23/96, Kelly Starks x7066 MS 10-39 wrote: >Ok, here my first cut of a summary of all the options we've come up with. >(or at least all I can remember.) I figure this is the next step up from >Zenons proposed table of contents. We might want to work this up to a >summary or central reference page for the LIT server. (More detailed >secoundary pages could brach off it.) I'll do more as I get some time. (I >working to finish the first draft of my secound novel! So I'll be >preoccupeid) > >Please review and comment. > >Kelly > > > > >============================================================ > Mission flight type >--------------------------------- >One-way > * Suicide (explore and die before your time when supplies end) > * One-way (Enough supplies are shipped to stay in target system until >natural death) > > >(For some inexplicable reason this option has one or two strong advocates >within L.I.T.. I want it absolutely known that I neither approve or in >anyway support such an option. Nor would I in any credible situation >expect it to generate anything but revulsion among the general tax paying >public. Kelly Starks - The Author.) > >>Pros >The ship need only be designed for a one time, one way flight. This limits >the technical mission risk and requires less resources. > >Least likelihood of back contaminating Earth. > >Establishes temporary outpost in starsystem. > >Allows investigation of the starsystem to continue until al exploration >resources are exhausted or worn out. Presumably for a decade or so, >depending on the service life of the shuttles or their support facilities, >or the service life of the remotes. > >>Cons >To put it mildly the public acceptance of sending explorers out to die the >mission and die on the frontier is low. Risking dying maybe, but >assigned/left to die by superiors -- no way. Every politician within ear >shot will run in front of the closest camera to announce that he or she >will personally lead the witch-hunt to track down everyone connected with >suggesting this idea. > >It has been suggested (adamantly) by some members of the group, that this >might be justifiable under some situation, or that this would be acceptable >as a colonization mission, especially if the colony could be made >completely self sufficient from the start. Aside from the technical >impossibility of doing the latter. Its unlikely in the extreme, that such >risks would be acceptable in an initial mission. At the very least the >mission would have to be designed as a two way flight with the option of >founding a colony or outpost. Also their would be considerable debate as >to why we would want to set up a permanent outpost in a place we don't know >anything about, and have no idea if we'd want to stay at. This debate >would get louder when the continuing cost of supply flights was discussed. > >Other problems would be: > >The potential supply of skilled personnel would obviously drop, if they >knew they were to be abandoned in the system when they finished the >mission. Especially given that their project life expectancy (due to the >lack of 'modern' medical facilities) would drop by a few decades, all but a >few years of which they'd spend trapped in a traveling, or derelict ship. > >Lower information return to Earth due to limited baud rates of interstellar >communication. > >Projected types of crew termination > - Voluntary suicide at end of exploration phase of mission. >This is likely as some crewmen decide to avoid living out the rest of their >years imprisoned in a derelict ship. > > - Death due to catastrophic failure of vital ship systems as the ship >wears out. >Obviously the ships systems won't last forever, and can't be rebuilt or >replaced completely. At some point it will simply wear out and fail. This >could be a single failure, like a major structural breach of the habitation >or support systems due to metal fatigue. Or a accumulation of lesser >failure as sub-systems begin to unravel. > > - Death due to medical limitations. >Given the limited medical facilities and personnel available on the ship. >Crew life expectancies would be far less than those who stayed at home with >access to modern medical care. Given the mid 21st century high-tech >population would conservatively have a projected life expectancy of 100-130 >years, with elongated vigorous years. (Some estimates are far higher.) >The crews limited medical life expectancy may still be nearly current US >norms. > > - Death due to chronic crew failure. >At some point the crew will simply be to old to maintain and operate the >ship, or provide their own medical care. At this point, without a follow >on generation to rescue or care for them, they will slowly or quickly die >off due to a combination of the above listed causes. > > >--------------------------------- >Round trip (Crew returns to Earth with ship at mission end.) > >>Pros >Simplest option, and one with little likely hood of public objection. > >More likely to get more volunteers and better qualified volunteers for flight. > >This option implies that the mission is fairly short. I.E. within the >professional life of the crew. This would imply its short enough to return >information in a useful amount of time. (I.E. it would get there and back, >before a later faster flight could do it.) > >It would return far more information than an interstellar communications >link could manage. > >It obviously avoids the grisly public relations and crew morale problems of >a one way mission. > >>cons >Technically more challenging. Getting a ship to the target starsystem is >hard enough. Getting it back would make it harder. But this must be >traded off against the added complexity of a ship capable of supporting its >crew for the rest of their lives. > > It has to be a fast enough ship to get back in an acceptable amount of >time. To slow and theirs no practical reason to send it. > > > >--------------------------------- >Pick up and return by follow on flight > >>Pros >Most of the advantages of the round trip model, and would allow the first >ship to be a mobile research station or other specialized ship, with faster >courier ships providing round trip flights. > >>cons >High risk and more complicated. Multiple ship types, and concerns that the >first ship might be left stranded. > > >--------------------------------- >Crew constructs equipment for return flight >This option come up with light/microwave sail craft, beamed power craft, >and fuel launcher craft. The crew would construct automated duplicates of >the systems that launched the ship from Sol space. > >>Pros >Would establish launcher facilities in both star systems. Which could >allowing faster two way flights with specialized fast light ships. > >The crew might get back faster with their ship using the constructed >launcher systems for assistance. > >cons >If they can't build the equipment, they don't get home. > >The construction phase may require so many resources that the first flight >is devoted just to infrastructure construction. With little or no >exploration being done in the first mission. This obviously would cool >public interest and slow down the return of productive information. > > > > >--------------------------------- >Multi-step. (Ship proceeds to other target star after completion of first >mission, in first starsystem.) > >>Pros >One mission explores multiple star systems. > >>cons >Technical feasibility is low since wear and tear on the ship would >accumulate, dramatically increasing the likelihood of a catastrophic >failure. > >Because of the extremely long flight times with likely technology, the >mission would take so long as to be undesirable. At some point the ship >would be superseded by newer faster ships sent straight out from earth, >decades after its launch. > > >--------------------------------- >Multi-generation Succeeding generations of crew continue the mission > >>Pros >This is the one of the standard concepts suggested to get around the >extremely long flight times. > >Could allow extremely long flight times. > >cons >The ship would have to be huge to support the active crew, >retired/incapacitated crew, children, and all the extra support facilities >and personnel they would require. > >The crew, ship, and equipment would need to be even larger than that to >allow them to be able to completely rebuild the ship from the inside out as >it, and its systems, exceeded their service lives. > >Any ship that takes that long to get to where it wants to go, will probably >find it gets there after newer faster ships from earth. So their is little >reason to launch it. > >The flight would take so long few people would be enthusiastic in launching >it, even if they didn't consider the likelihood of faster follow on craft. >I.E. why spend money on something you'll never see the results of, nor even >ever know if they made it. > >The follow on generation(s) in the ship will have no allegiance or >commitment to the mission or its originators (they, never agreed to >anything). > >The follow on generations would have no hands-on experience with the >exploration systems they would be expected to use. Or for that matter, any >experience with planets and starsystems. > >Its harder to get qualified people to go on such a flight. People who want >to explore wouldn't want to spend the rest of their life stuck in a ship, >knowing they will never contribute anything but their genes. > > > >--------------------------------- >Hibernation flight >>Pros >This is the other one of the standard concepts suggested to get around the >extremely long flight times. > >The ship would not need to support the inactive crew. > >The crew wouldn't need to spend years of their lives waiting around in the >ship with nothing to do until they get to the star system. > >The crew will still be fresh and familiar with their jobs when then are >waken up in the star system. > > >>cons >The ship systems will still exceeded their service lives, but their may not >be enough people around to service them. The sleepers could wind up dying >on route as the ship died around them. > >The sleepers would have to be extremely well shielded from radiation, since >their cell repair mechanisms would be as dead as they are. > >Any ship that takes that long to get to where it wants to go, will probably >find it gets there after newer faster ships from earth. > >The flight would take so long few people would be enthusiastic in launching it. > > > > > > technical political Desirability > Risk Feasibility risk Feasibility >------------------------------------------------------------- >One-way med-low Medium Ex-high Nil Low >Round trip medium medium low High high >Pick-up Med-high medium medium medium medium >Construct ret high med-high medium medium medium >Multi-step Ex-High. med-low low Medium medium >Multi-gen Ex-high Low high medium low >Hibernation high Low medium medium low > > > > > >------------------------------- > >============================================================ >Alternatives >--------------------------------- >robotic fly by's > >>Pro >Could use a smaller lighter ship and could tolerate longer flight times. > >>Con >requires extremely good A.I. systems and reliability (which may or may not >be likely by 2050), and would generate far less public interest. > >Why bother, you could do nearly as well with huge telescope systems in the >Sol star systems > > >--------------------------------- >Robotic exploration > >>Pro >Could use a far smaller lighter ship and could tolerate longer flight times. > >>Con >Again requires extremely good A.I. systems and reliability, and would >generate less public interest. > >Would be less capable than a manned mission. > > > > >============================================================ >Mission purpose >--------------------------------- >Colonization of planets or moons > >>Pro >Very popular idea with public. > >Excellent staging area for direct examination of that planet or moon. > >>Con >Expensive. Either the colony would need to be the size of a major city to >support all of the specialists needed to support a self sustaining society, >or regular (extremely expensive) supply flights from earth would be >necessary. > >On a planet with a Earth-like ecology it would be a biological death trap. >Alien microbes, allergens, and other unknowns life forms would easily >defeat unprepared Earth mammalian immune systems. > >On a planet with a non-Earth-like ecology it still could be a biological >death trap, and in addition have basic climate and biosphere >incompatibilities (Wrong temperatures, air pressures, gravity). > >Isolation from resources. Ores, energy and raw materials are far harder to >access on a planet than in space. > >Isolation from other planets. > >Their doesn't seem to be enough practical justification for such a massive >undertaking. > > >--------------------------------- >Colonization of constructed space platforms > >>Pro >Still may be a very popular idea with public. > >Excellent staging area for examination of the solar system. > >Much lower biological threat than on a planet with biosphere. > >The internal gravity, radiation, and environment can be precisely tailored >to humans. > >Far easier to construct and service than a planet bound colony. > >Easy access to plentiful resources. (Space is considered so much richer in >cheap, easy to access resources and power. That it is expected that >Earth's heavy industry will migrate into space in the next century.) > >Could act as a servicing center and supply port for the starship, or >subsequent starships. > > >>Con >Expensive. Either the colony would need to be the size of a major city to >support all of the specialists needed to support a self sustaining society, >or regular (extremely expensive) supply flights from earth would be >necessary. > >Their doesn't seem to be enough practical justification for such a massive >undertaking. > > > >--------------------------------- >Infrastructure construction > >>Pro >This could establish facilities necessary for routine, lower cost, flights >between home and this starsystem. > >>Con >Construction could take so many resources that little or no exploration >will be done. > >Less interesting to public than an exploration or colony program. > >Could be very expensive. > > >-------------------------------------------------- >============================================================ >propulsion systems >--------------------------------- >Fusion feed from internal fuel sources. > >A fusion powered rocket could cross interstellar distances, and is a near >term enough technology to be considered likely for the mid 21st century. >Unfortunately the amount of fuel it takes to get such a ship up to a usable >speed (at least 1/5th of light speed is necessary. More than a 1/3rd is >highly desirable.) is not carryable by such a ship. Since the fuel would >weigh hundreds to thousands of times as much as the rest of the ship. > >For example for a fusion rocket with a specific impulse of 1,000,000. If >you wanted to use such an engine to accelerate a ship up to 1/6th the speed >of light. The ship would need to carry 147 times its dry weight in fuel. >If you want to get to 1/3rd the speed of light, it would need to carry >22,000 times its weight in fuel! Obviously no realistic ship could do >this. > >(Note: a specific impulse of 1,000,000 (A exhaust velocity of >10,000,000m/s) means that the engine gives 1,000,000 pounds of thrust, for >one second, for every pound of fuel consumed. This has long been >considered a very do-able fusion performance number. For comparison the >best chemical engines have a specific impulse of 455.) > >--------------------------------- >Staged fusion ship > >You start with a 1 billion ton fueled ship cluster driven by a 10 million >ton engine and support structure (yeah right.). That engine is powerful >enough to push the whole mess with an acceleration rate of 10m/s. > >When you burn off 95% of your weight in fuel. The ship cluster weighs 50 >million tons, 20% of which is a first stage engine/structure that's WAY too >powerful. You throw the first stage away and start a smaller second stage. >It weighs about 400,000 tons (about as much as 4 aircraft carriers) and >can push the 40,000,000 ton ship cluster. When you burn that down to >2,000,000 tons of cluster you throw that away that stage for a 70,000 ton >ship with 5-10,000 tons of drive systems. Which can use the remaining >390,000 tons of fuel to get itself into the system. > >stage total weight (tons) thruster pack and stage structure >1 1,000,000,000 10,000,000 >2 40,000,000 400,000 >3 2,000,000 70,000 ton ship > with 5-10,000 tons of > drive systems. > >This assumes a 100 to 1 thrust to weight ration for a fusion drive systems >(which is questionable), and once you get where your going, coming back is >out (unless of course you scale the craft up accordingly). But it would >give us huge fuel ratios for relativistic flight. So, in theory, a Multi >stage fusion craft could get to the star. Assuming of course you can find >a billion tons of fusion fuel, and a ship yard in space that can construct >a ship the size of an asteroid! Which means in practice the ship is >unbuildable. > >These numbers of course assume the ship has to carry the weight of its >fuel. Obviously craft normally have to carry their fuel, but their are >some ways around it. > >--------------------------------- >Fusion with externally feed fuel sources > >A fuel launcher is a linear accelerator mounted somewhere in our solar >system. It throws the fuel out in front of where the ship is going to fly. >The ship scoops up the fuel as its going along. This has several >advantages. The ships engines only need to accelerate the ship itself. >(They don't even have to adjust for changing ship weights.) The fuel is >accelerated up by the launcher. This means the launcher system (who's >power comes from unaccelerated fuel) takes up a large fraction of the load, >and the ship saves a lot of energy. > >Problems are that unless the ship is flying to a starsystem with a >operating fuel launcher. It can't fly any faster then a speed it can >decelerate from using its onboard fuel reserves. Also, this only works >when your close enough to the launcher that it can accurately launch the >fuel to you. Once your out of range, your stuck with fuel your caring. > >Fuel launchers (or beamed power) have the advantage of eliminating the need >for the ship to carry the heavy fuel (and power systems). That improves >the ships power to weight ratio significantly. But the systems are >difficult to do, limit range, and don't seem to help us to slow down. > > > >Beamed power > >Beamed power (or fuel launchers) have the advantage of eliminating the need >for the ship to carry the heavy fuel (and power systems). That improves >the ships power to weight ratio significantly. But the systems are >difficult to do, limit range, and don't seem to help us to slow down. > >Beamed power systems are most effective as microwave sail craft. But >powered electromagnetic drives are possible also. > > >Anti-matter >Can be destroyed to create tremendous amounts of energy. Releases over a >hundred times as much power per pound of fuel as a fusion reaction. > >Unfortunately, though it releases more power, this power is harder to >directly use to power the ship. It is however far more dangerous to >handle. If we could synthesize the thousands of tons of antimatter this >would take. It would have the potential of exploding with a force of >hundreds of millions of H-bombs. > >We do not have the technology needed to synthesis, store, or ship >anti-matter on this scale, and are not likely to get it by 2050. > >Ramscoop > >This idea would allow a ship to scoop up interstellar hydrogen and use it >for fuel. Like a fuel launcher system it could accelerate to high speeds >without concern for high fuel to weight ratio's. > >Unfortunately we don't really know what's in interstellar space, but we do >know we are in a very thin part of it due to a recent supernova in the >area. We might need a scoop thousands of kilometers across for a decent >sized ship. > >We also know that straight hydrogen is very hard to fuse, and doesn't fuse >as quickly as we might need. > >All in all we have no real idea on how to make such a ship work. > > > >Future tech > >The engineering and science we have now and assume we will have in the >future will change. Fusion, fission, relativity, quantum mechanics, and a >host of other basics of current physics; all were discovered within the >last hundred years. We can conservatively expect physics to have changed >far more in the next hundred years, then it did in the last hundred years. >What technologies that age will have on hand are impossible to guess. They >could have matter conversion, hyperlight drives, new understandings of >inertia and kinetic energy, or all those and far more. Any of these would >dramatically effect our ability to travel between the stars. So even >though we can't come up with any practical ideas for exploring the stars >now, we can be sure our descendants will find it far easier than we >imagine. > >Kelly Starks > > > >---------------------------------------------------------------------- > >Kelly Starks Internet: kgstar@most.fw.hac.com >Sr. Systems Engineer >Magnavox Electronic Systems Company >(Magnavox URL: http://www.fw.hac.com/external.html) > >---------------------------------------------------------------------- ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Thu Feb 1 16:36:08 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6750" "Thu" "1" "February" "1996" "10:24:39" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "167" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA22264 for ; Thu, 1 Feb 1996 08:23:32 -0800 (PST) Received: by maroon.tc.umn.edu; Thu, 1 Feb 96 10:24:41 -0600 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Kelly Starks x7066 MS 10-39 cc: Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Re: Fwd: LIT e-mail discussion group Date: Thu, 1 Feb 1996 10:24:39 -0600 (CST) On Thu, 1 Feb 1996, Kelly Starks x7066 MS 10-39 wrote: > Ah, its been about a week since I sent out my draft summarry document > (attached), and (other then Daves compliment) I haven't heard any responce > to it. No one has any complaints, things they want added, changed etc? > > Kelly Actually, I found most of what you said to be fair and balanced. Some of it may be _wrong_, but i can't prove it (yet) For one-way trips, I agree that they are undesirable. I agree that very little supoort would be generated. I disagree that there won't ever be a situation in which we'd have to send one. I agree that we should try evey thing else first, and then as a last resort see if we can make a one-way trip. > > >Round trip (Crew returns to Earth with ship at mission end.) > > > >--------------------------------- > >Pick up and return by follow on flight I think we need to look into this idea some more, I don't think we have given it enough consideration to discard it too quickly. > > > >>Pros > >Most of the advantages of the round trip model, and would allow the first > >ship to be a mobile research station or other specialized ship, with faster > >courier ships providing round trip flights. > > > >>cons > >High risk and more complicated. Multiple ship types, and concerns that the > >first ship might be left stranded. I don't think the multiple ship types is all that worrisome, I think that the engines would be the same, so the only difference would be the hab rings, etc. specialized equipment. > >--------------------------------- > >Crew constructs equipment for return flight > >This option come up with light/microwave sail craft, beamed power craft, > >and fuel launcher craft. The crew would construct automated duplicates of > >the systems that launched the ship from Sol space. > > > >>Pros > >Would establish launcher facilities in both star systems. Which could > >allowing faster two way flights with specialized fast light ships. > > > >The crew might get back faster with their ship using the constructed > >launcher systems for assistance. > > > >cons > >If they can't build the equipment, they don't get home. perhaps they should be required to build the sol-based launching system as a dry-run. > > > >The construction phase may require so many resources that the first flight > >is devoted just to infrastructure construction. With little or no > >exploration being done in the first mission. This obviously would cool > >public interest and slow down the return of productive information. I really see the developement of a two-tiered crew. one set flys the ship, and builds the return infrastructure. the other set does the exploration and analysis of the data. The flight crew may not have any real work in the target system, so they may be the logical choice to build the return infrastructure. > >--------------------------------- > >Multi-step. (Ship proceeds to other target star after completion of first > >mission, in first starsystem.) > > > >>Pros > >One mission explores multiple star systems. > > > >>cons > >Technical feasibility is low since wear and tear on the ship would > >accumulate, dramatically increasing the likelihood of a catastrophic > >failure. > > > >Because of the extremely long flight times with likely technology, the > >mission would take so long as to be undesirable. At some point the ship > >would be superseded by newer faster ships sent straight out from earth, > >decades after its launch. Agreed > > technical political Desirability > > Risk Feasibility risk Feasibility > >------------------------------------------------------------- > >One-way med-low Medium Ex-high Nil Low > >Round trip medium medium low High high > >Pick-up Med-high medium medium medium medium > >Construct ret high med-high medium medium medium > >Multi-step Ex-High. med-low low Medium medium > >Multi-gen Ex-high Low high medium low > >Hibernation high Low medium medium low > > I think the risk factor on construction return is too high, it should be medium to medium-low, the technology should be well-tested before the ship leaves earth. The political feasibility should be higher also, because we won't have to pay for the return flight, the explorers (or their robotic helpers) will build the solar arrays to power the return flight. I would say the desirability of the construction return option is medium high to high. Other wise I agree with your other analysises > >--------------------------------- > >Infrastructure construction > > > >>Pro > >This could establish facilities necessary for routine, lower cost, flights > >between home and this starsystem. > > > >>Con > >Construction could take so many resources that little or no exploration > >will be done. Again, I think there will be plenty of resources, given self-replicating robots. They don't have to be human-equivilent thinkers. they only have to have the _intelligence_ (as opposed to the capabilities) of a bee or a microbe. Think of the incrediblly complex hive that bees can make with limited thinking abilities. > > > >Less interesting to public than an exploration or colony program. if it was done co-currently with the exploration, then I don't think the public would mind. > >propulsion systems > >--------------------------------- > >--------------------------------- > >Staged fusion ship there is an equation that gives the maximum limits of a staged vehivle, but I don't know what it is. there is a point where adding another stage actually takes more power away from the engines than you get from the engines, this is known as the point of diminishing returns. > >Beamed power > > > >Beamed power (or fuel launchers) have the advantage of eliminating the need > >for the ship to carry the heavy fuel (and power systems). That improves > >the ships power to weight ratio significantly. But the systems are > >difficult to do, limit range, and don't seem to help us to slow down. > > > >Beamed power systems are most effective as microwave sail craft. But > >powered electromagnetic drives are possible also. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ And probably required for the mid-point to Target portion of the trip if you intend to travel near light-speed. Kevin (who wants the maser energy to heat up this frozen wasteland, so that I don't have to live in -26 F (-32 C) anymore) P.S. to Timothy, tell the BBC that We'd love to talk with them. I for one would have no problem doing an interview. :) From popserver Thu Feb 1 17:17:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9174" "Thu" "1" "February" "1996" "12:10:15" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "225" "Re: Summary draft comments" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA25938 for ; Thu, 1 Feb 1996 09:12:53 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA26762; Thu, 1 Feb 96 12:13:54 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI026555; Thu Feb 1 12:11:28 1996 Received: by most (4.1/SMI-4.1) id AA06299; Thu, 1 Feb 96 12:11:22 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma006261; Thu Feb 1 12:10:16 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA07206; Thu, 1 Feb 96 12:10:13 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Re: Summary draft comments Date: Thu, 1 Feb 1996 12:10:15 -0500 At 10:24 AM 2/1/96, Kevin C Houston wrote: >On Thu, 1 Feb 1996, Kelly Starks x7066 MS 10-39 wrote: > >> Ah, its been about a week since I sent out my draft summarry document >> (attached), and (other then Daves compliment) I haven't heard any responce >> to it. No one has any complaints, things they want added, changed etc? >> >> Kelly > >Actually, I found most of what you said to be fair and balanced. Some of >it may be _wrong_, but i can't prove it (yet) Thanks, and yes much of it could be wrong, but I figured we have to start somewhere. >For one-way trips, I agree that they are undesirable. I agree that very >little supoort would be generated. I disagree that there won't ever be a >situation in which we'd have to send one. I agree that we should try >evey thing else first, and then as a last resort see if we can make a >one-way trip. Ever is a long time. I mean if the sun was going into a violent phase we might be desperate enough for everything. But none of those things seems likely in 2050. In general a interstellar mission is a like-to-do, rather than a need-to-do. > >> > >Round trip (Crew returns to Earth with ship at mission end.) >> > >> >--------------------------------- >> >Pick up and return by follow on flight > >I think we need to look into this idea some more, I don't think we have >given it enough consideration to discard it too quickly. It would have real advantages, if the follow up ship could take advantage of completed infastructure to travel at higher speeds. But it would mean the follow up ship would have to launch without knowing is their was an infastructure there to catch it. >> > >> >>Pros >> >Most of the advantages of the round trip model, and would allow the first >> >ship to be a mobile research station or other specialized ship, with faster >> >courier ships providing round trip flights. >> > >> >>cons >> >High risk and more complicated. Multiple ship types, and concerns that the >> >first ship might be left stranded. > >I don't think the multiple ship types is all that worrisome, I think that >the engines would be the same, so the only difference would be the hab >rings, etc. specialized equipment. Ship types is a engineer and complexity issue (you'ld be amazed how much trouble little modifications), but the stranded ship problem would be critical. Possibly the first ship could have (slower) self return capacity. >> >--------------------------------- >> >Crew constructs equipment for return flight >> >This option come up with light/microwave sail craft, beamed power craft, >> >and fuel launcher craft. The crew would construct automated duplicates of >> >the systems that launched the ship from Sol space. >> > >> >>Pros >> >Would establish launcher facilities in both star systems. Which could >> >allowing faster two way flights with specialized fast light ships. >> > >> >The crew might get back faster with their ship using the constructed >> >launcher systems for assistance. >> > >> >cons >> >If they can't build the equipment, they don't get home. > >perhaps they should be required to build the sol-based launching system >as a dry-run. Definatly! >> > >> >The construction phase may require so many resources that the first flight >> >is devoted just to infrastructure construction. With little or no >> >exploration being done in the first mission. This obviously would cool >> >public interest and slow down the return of productive information. > >I really see the developement of a two-tiered crew. one set flys the >ship, and builds the return infrastructure. the other set does the >exploration and analysis of the data. The flight crew may not have any >real work in the target system, so they may be the logical choice to >build the return infrastructure. Definatly some kind of multi crew designation. Maybe I should ty to rough out a crew structure? >> >--------------------------------- >> >Multi-step. (Ship proceeds to other target star after completion of first >> >mission, in first starsystem.) >> > >> >>Pros >> >One mission explores multiple star systems. >> > >> >>cons >> >Technical feasibility is low since wear and tear on the ship would >> >accumulate, dramatically increasing the likelihood of a catastrophic >> >failure. >> > >> >Because of the extremely long flight times with likely technology, the >> >mission would take so long as to be undesirable. At some point the ship >> >would be superseded by newer faster ships sent straight out from earth, >> >decades after its launch. > >Agreed > > >> > technical political Desirability >> > Risk Feasibility risk Feasibility >> >------------------------------------------------------------- >> >One-way med-low Medium Ex-high Nil Low >> >Round trip medium medium low High high >> >Pick-up Med-high medium medium medium medium >> >Construct ret high med-high medium medium medium >> >Multi-step Ex-High. med-low low Medium medium >> >Multi-gen Ex-high Low high medium low >> >Hibernation high Low medium medium low >> > > >I think the risk factor on construction return is too high, it should be >medium to medium-low, the technology should be well-tested before the ship >leaves earth. The political feasibility should be higher also, because >we won't have to pay for the return flight, the explorers (or their >robotic helpers) will build the solar arrays to power the return flight. >I would say the desirability of the construction return option is medium >high to high. Other wise I agree with your other analysises Well we'ld have to pay for the return flight one way or the other. I also worryied about a crew without backup, and years out of practice, tring to build a massive infastructure in an area they may not know anything about. I mean what if they can't find some critical resource, or find the area has an unexpected problem. >> >--------------------------------- >> >Infrastructure construction >> > >> >>Pro >> >This could establish facilities necessary for routine, lower cost, flights >> >between home and this starsystem. >> > >> >>Con >> >Construction could take so many resources that little or no exploration >> >will be done. > >Again, I think there will be plenty of resources, given self-replicating >robots. They don't have to be human-equivilent thinkers. they only have >to have the _intelligence_ (as opposed to the capabilities) of a bee or a >microbe. Think of the incrediblly complex hive that bees can make with >limited thinking abilities. I think self replicating robots is a high risk tech. So far we've never gotten close to developing it. So depending on it for some critical process worries me. On the other hand I've been thinking of expanding the ultra tech sectioon and discus alternat missions given a couple of exotic technologies. >> > >> >Less interesting to public than an exploration or colony program. > >if it was done co-currently with the exploration, then I don't think the >public would mind. Oh, yes. I was refering to a mission that only did infastructure. A mixed mission would be possible, but could get very big and expensive. >> >propulsion systems >> >--------------------------------- >> >--------------------------------- >> >Staged fusion ship > >there is an equation that gives the maximum limits of a staged vehivle, >but I don't know what it is. there is a point where adding another stage >actually takes more power away from the engines than you get from the >engines, this is known as the point of diminishing returns. Yeah unless the later stages have incrediable spec. imp., its a no go. >> >Beamed power >> > >> >Beamed power (or fuel launchers) have the advantage of eliminating the need >> >for the ship to carry the heavy fuel (and power systems). That improves >> >the ships power to weight ratio significantly. But the systems are >> >difficult to do, limit range, and don't seem to help us to slow down. >> > >> >Beamed power systems are most effective as microwave sail craft. But >> >powered electromagnetic drives are possible also. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >And probably required for the mid-point to Target portion of the trip if >you intend to travel near light-speed. We certainly need something. >Kevin (who wants the maser energy to heat up this frozen wasteland, so >that I don't have to live in -26 F (-32 C) anymore) YEOW! I'm glad I didn't take that job in Mini-St.P. Then again, I really hate Ft. Wayne. >P.S. to Timothy, tell the BBC that We'd love to talk with them. I for >one would have no problem doing an interview. :) ?? I'll incorporate your comments in the next draft. Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Thu Feb 1 23:41:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["962" "Fri" "2" "February" "1996" "00:17:25" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "16" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA26340 for ; Thu, 1 Feb 1996 15:17:05 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15284 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 00:17:09 +0100 Message-Id: <199602012317.AA15284@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 02 Feb 1996 00:17:25 +0100 >A Submarines Inertial Navigation System is calibrated before the boat ever >goes on its' first seatrial. Any adjustments are done at that time. Any fine >tuning later would prbably be done in a shipyard. Befxore the boat was >commissioned the Nav System would have been signed off as a matter of >course. In the whole time I was aboard we never had to adjust ours. To get a >"satnav" fix you would have to put a parascope up, (they have a stack of >antenas on the top of them,) and get your satalite fixes. Parascopes even >have a sextent in them to do star and moon and sun sights from parascope >depth. The Inertial Nav System works off of the gyro cumpuses, shaft speed, >current speed and direction and course steared. In my day it was a computer >the size of a refrigerator. I'm sure it is much smaller now. I think I have misunderstood it when they said they had to come to the surface for recalibration, indeed a few antennas will do as well. Timothy From popserver Thu Feb 1 23:41:11 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["892" "Fri" "2" "February" "1996" "00:17:40" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "27" "Wrong person?" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA26363 for ; Thu, 1 Feb 1996 15:17:25 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15300 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 00:17:28 +0100 Message-Id: <199602012317.AA15300@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Wrong person? Date: Fri, 02 Feb 1996 00:17:40 +0100 Kevin, you wrote this: >P.S. to Timothy, tell the BBC that We'd love to talk with them. I for >one would have no problem doing an interview. :) I'm not sure if you are adressing the right person, it was David who wrote that message. David wrote: >Hey, all, I've just been contacted by the BBC via email about >a television show they want to do this summer about >how science fiction becomes science fact. I'm not >sure they understand that LIT is a bunch of amateur >starship designers, and not actual professors or >anything. I'm not sure what to tell them. I've been >thinking about just explaining the situation to them, >explaining exactly what it is we're doing, and perhaps >giving them email addresses of good people to contact >whom I've met through LIT (like Zenon, if you'd want?)... David, is there a special reason you are addressing Zenon. (Just curious) Timothy From popserver Thu Feb 1 23:41:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10629" "Fri" "2" "February" "1996" "00:17:33" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "243" "Re: Fwd: LIT e-mail discussion group" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA26379 for ; Thu, 1 Feb 1996 15:17:39 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15291 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 00:17:18 +0100 Message-Id: <199602012317.AA15291@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl (Unverified) X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Fwd: LIT e-mail discussion group Date: Fri, 02 Feb 1996 00:17:33 +0100 I had to think it over a while, but thanks for reminding: >One-way > * Suicide (explore and die before your time when supplies end) > * One-way (Enough supplies are shipped to stay in target system > until natural death) >>Pros >The ship need only be designed for a one time, one way flight. This limits >the technical mission risk and requires less resources. Actually there may be an equal or bigger amount of resources. That depends on if the crew needs to be larger and if more appliances are needed. If instead of 1E9 kg of fuel you could bring extra crew and appliances that would probably make a "colonalization" more probable to succeed. >Lower information return to Earth due to limited baud rates of interstellar >communication. Assuming we are able to create 1E18 Watts I think that bandwidth is minor problem. ============================================================================== >Round trip (Crew returns to Earth with ship at mission end.) > >>Pros >Simplest option, and one with little likely hood of public objection. I'm not sure what you mean with simplest, I think only the part after the comma is true. >It obviously avoids the grisly public relations and crew morale problems of >a one way mission. Seems to me that you use this twice as a pro in this mission. >>cons >Technically more challenging. Getting a ship to the target starsystem is >hard enough. Getting it back would make it harder. But this must be >traded off against the added complexity of a ship capable of supporting its >crew for the rest of their lives. Indeed, but if we are not able to build a small colony during a one-way mission than the chances are small that we are able to build a complete power array for a two-way mission. So this means that all power for the return mission has to come Earth. ============================================================================== >Pick up and return by follow on flight >>cons >High risk and more complicated. Multiple ship types, and concerns that the >first ship might be left stranded. Also politically less preferable, because the project will take longer and probably twice the effort. ============================================================================== >Crew constructs equipment for return flight >This option come up with light/microwave sail craft, beamed power craft, >and fuel launcher craft. The crew would construct automated duplicates of >the systems that launched the ship from Sol space. > >>Pros >Would establish launcher facilities in both star systems. Which could >allowing faster two way flights with specialized fast light ships. This assumes that either people stay behind to control and repair the launcher or that we have AI that is smart enough to keep the thing working perfectly. !! This is something we have not discussed before as far as I know !! >The crew might get back faster with their ship using the constructed >launcher systems for assistance. >cons >If they can't build the equipment, they don't get home. > >The construction phase may require so many resources that the first flight >is devoted just to infrastructure construction. With little or no >exploration being done in the first mission. This obviously would cool >public interest and slow down the return of productive information. Again, if we are not able to build a small colony during a one-way mission than the chances are small that we are able to build a complete power array for a two-way mission. So this means that all power for the return mission has to come Earth. Although a power-array may require less different parts than a colony, the size it much bigger and it uses the same type of machinery that is required to build a colony. Another con is that less time is available for research, unless robots are a possibility. ============================================================================== >Multi-step. (Ship proceeds to other target star after completion of first >mission, in first starsystem.) > >>cons >Technical feasibility is low since wear and tear on the ship would >accumulate, dramatically increasing the likelihood of a catastrophic >failure. > >Because of the extremely long flight times with likely technology, the >mission would take so long as to be undesirable. At some point the ship >would be superseded by newer faster ships sent straight out from earth, >decades after its launch. Not even undesirable long, but probably too long. Also the conditions should be the same as a one-way mission and it needs much more energy ============================================================================== >Multi-generation Succeeding generations of crew continue the mission > >>Cons >The follow on generation(s) in the ship will have no allegiance or >commitment to the mission or its originators (they, never agreed to >anything). When children grow up in a certain environment, they may like it there. So it may be very likely that they will continue the mission. >The follow on generations would have no hands-on experience with the >exploration systems they would be expected to use. Or for that matter, any >experience with planets and starsystems. The could be trained just like the initial crew was, the ships computers will have a large amount of knowledge and learning tools. > technical political Desirability > Risk Feasibility risk Feasibility >------------------------------------------------------------- >One-way med-low Medium Ex-high Nil Low >Round trip medium medium low High high >Pick-up Med-high medium medium medium medium >Construct ret high med-high medium medium medium >Multi-step Ex-High. med-low low Medium medium >Multi-gen Ex-high Low high medium low >Hibernation high Low medium medium low The feasability of a round trip probably depends on the creation of a power source at TC. I think that if that power source can be created, a colony for a one-way mission can be build also. That makes the political feasability much higher. Maybe even higher than a two way mission. I would find it more exciting to know there people building on a new civilazation than on a back and forth mission. If the colony could prosper its (political & scientific) value is much higher than a two way mission. Multi-step, Multi-gen and hibernation ships all have the same condition(=a working ship for >40 years) as a one-way mission so I think they should have the same political feasability. The difference between constrution-return and round-trip are not clear since we haven't defined how(=what energy source) the round-trip makes its return. So its not clear how the differences in feasability are explained. ============================================================================= >Mission purpose >--------------------------------- >Colonization of planets or moons >Isolation from resources. Ores, energy and raw materials are far harder to >access on a planet than in space. If the death-trap could be overcome be medical care, it may be more pleasant to live on a new (fresh) planet than in a space station. ============================================================================= >propulsion systems >--------------------------------- >Fusion feed from internal fuel sources. >Staged fusion ship I think you shouldn't look at staging the "classical" way. Why not add hundreds of the same kind of engines and throw them away when not needed any more. Making many engines of the same type is probably cheaper than a few that differ in size. Another advantage is that when one becomes defect it's not a big deal (unless it is an error that each engine has). In fact this is just a ship with say 1000 stages. A problem with staging is that you throw away your ship, this makes a two-way mission much harder! >Anti-matter >Can be destroyed to create tremendous amounts of energy. Releases over a >hundred times as much power per pound of fuel as a fusion reaction. > >Unfortunately, though it releases more power, this power is harder to >directly use to power the ship. This is not certain, the ideas I stated some time ago are only a few and were considered as most preferred though less easy methods. There does not have to be a real difference between a fusion or an anti-matter powered ship. Both can be used as heat-energy sources to accelerate reaction mass. >It is however far more dangerous to >handle. If we could synthesize the thousands of tons of antimatter this >would take. It would have the potential of exploding with a force of >hundreds of millions of H-bombs. This explosion can only happen if there is an equal amount of matter nearby. I think it may be possible to keep the anti-matter far enough away (in a large torus for example) Of course even when a minor amount of anti-matter is "spilled" the ship is likely not to reach its final goal (but does not have to explode). So while your argument is not completly right, the idea is. But of course when a major engine of the ship stops working indefinately this may also be the case. >Future tech > >The engineering and science we have now and assume we will have in the >future will change. Fusion, fission, relativity, quantum mechanics, and a >host of other basics of current physics; all were discovered within the >last hundred years. We can conservatively expect physics to have changed >far more in the next hundred years, then it did in the last hundred years. >What technologies that age will have on hand are impossible to guess. They >could have matter conversion, hyperlight drives, new understandings of >inertia and kinetic energy, or all those and far more. Any of these would >dramatically effect our ability to travel between the stars. So even >though we can't come up with any practical ideas for exploring the stars >now, we can be sure our descendants will find it far easier than we >imagine. FTL is a principle that has been withstanding many experiments to unprove it. Chances are small that FTL will become possible in the next century (if at all). ========================================================================== A possible disavantage for a two way trip is that the crew has to live a long time in a ship. If it is a disadvantage depends on the size of the ship, if this is a disadvantage for a one way mission depends on the possibility to extend the ship when at TC. Timothy From popserver Fri Feb 2 05:12:28 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3246" "Fri" "2" "February" "1996" "00:08:28" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "72" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA23632 for ; Thu, 1 Feb 1996 21:08:54 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id AAA17063; Fri, 2 Feb 1996 00:08:28 -0500 Message-ID: <960202000827_212110281@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Fri, 2 Feb 1996 00:08:28 -0500 >???!! TV's have changed dramatically in the last thirty years. Not the >picture format, which is fixed by law, but the image clarity and relyability >is far better. That of course ignores the fact that current TV's are about >to be phased out for digital HDTV's (at least in the states). >> Yes, but untill HDTV (which is more or less the logical >> step to digital multi media and communication) these >> improvements are not so big that every living soul >> (overstatement) wants to buy a new television. What I was going for was that the TV's them selves have changed dramatically without HDTV. These changes in image quality and relyability were enough that everyone went out to get a new set. I wounder if the internet will wind up becoming part international cable television? >Virtually all major feilds from industrial architecture, computers, >industrial manufacture, chemistry, aviation, farming, have all seen dramatic >improvements. Theses improvements don't always do something obvious, but >they are there. >> But are these advancements accelerations or just steady growth? Acceleration. Most industries talk about the double time of the knowledge base of their field. Thats an exponential growth curve. >> Rethinking it, I come to the conclusion that as soon as AI >> has an IQ of 80 it will only take a few years to reach 180. Less than that. Computer systems have maintained a 100 fold improvement in performance per decade for over half a century. Hard to tell how A.I. would fit into that. We might make a breakthrough (like in my book) and have everything fall into place in months, or we might stumble along for decades. >As for us and super intelegent AI's. Eiather we'll find something to do >together (or co-evolve), or they will move on and ignore us. (We can hardly >expect them to take care of us forever.) >> Maybe we should make them just smart enough to do >> the dirty jobs. And use only a few with IQ 1000 to think. ;) You can't hide forever. Best to come out a deal with things as theyt happen, not try to lock yourself into a safe past. >The biggest computer I know of personally is a 4-5 tera byte (E12 byte >system) being constructed in my old neighborhood in Reston Virgina for the >phone companies cable TV experement. The Cray corporation is building a 9 >teraflop system for the US government DARPA research agency (completion >scheduled for 1998), and their competitor (thinking machines) is offering a 2 >teraflop system comercially for $100 million. >> Yes, I found some info about another CRAY having max 1.2 TFLOPS. Ok, so we have the electronic brains. Now for the minds! >So we already are building systems bigger and more powerfull than the human >brain, we just don't really know how to make them think. True intelegence >may require custom circutry. But that circutry could be built in a way >similar to the current circuts. If of course it does need couston circuts, >which is hotly debated. > Custom circuis are is less efficient to do highly parallel computing than > neural-circuits. --- I was refering to neural net circuts. We alread know how to make them to the same consentration as standard circuts, but so far they arn't as usfull. Kelly From popserver Fri Feb 2 05:12:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6409" "Fri" "2" "February" "1996" "00:08:44" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "164" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA23649 for ; Thu, 1 Feb 1996 21:09:21 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id AAA26826; Fri, 2 Feb 1996 00:08:44 -0500 Message-ID: <960202000842_212110478@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 2 Feb 1996 00:08:44 -0500 To: Timothy van der Linden) > To Kelly: > > >Yeah, Its assumed that you need a minimum size to have enough cells, for > >enough interconnections, to get a complex enough brain; But you also need a > >big enough brain to body ration so the brain has enough excess power to spare > >on complexity. > > But why do elephants have such big brains (3 to 4 times larger than humans)? They need the nuerons to run their big bodies, which are dozens of times humans. > >Automation allows a few skilled people to do the work of a larger number of > >people without automation. It does not allow the automation system to work > >by itself without people. As long as their are people to fix and operate it, > >automate systems will work well and productivly. Which is why all large > >manufacturing industries use them. > > But that means that much less people can do the job Yes. > >> Forget the predictions, it is proven than several gasses like CO2 and SO2 > >> have very well insulating properties. So the fact that these gasses are > >> present in abundance on Venus means that a greenhouse-effect is > >> responsable for the high temperature. > > > >No it doesn't, it just meen their are insulating gases in the air. It > >doesn't even tell you if they are keeping heat in, or out. > > It's keeping the heat in: Greenhouse gasses are more opaque planetary > radiation than for solar radiation. Solar radiation is what directly comes > from the Sun and planetary radiation is I know the theory, I also know their is no data to support it. > As for the debacle about Earth's greenhouse effect, there are only doubts > about the quantity of the temperature increase caused by the greenhouse > gasses. Also it is argued if the greenhouse gasses are the only reason for > temperature increase. It is also argued if the earth is getting warmer or cooler. NASA went back over 25-30 years of satelihgt scans. They could have detected a change as small as 1/5th the smallest variation predicted by any of the green house theories. They didn't find it. Longer term arcio-climatology studies have shown a cooling since the mid 1800, a warming from the 1700, and a long term cooling over the last 800 years. > >> Yes, but that is because Earth has a biosphere. If Earth had to do without > >> that and it would be moved to the place of Venus, then is would heat up and > >> once the greenhouse-effect took over there wouldn't be a way back. > > > >No, earth biosphere trims its temperature a bit, but not by hundreds of > >degrees! If that were true Earth would have been unable to ever evolve life. > > To that I agree, but as long the greenhouse effect is not too large the > temperatures will not become so high that no live can exist. At the > light-side of the moon you will freeze to death (assuming you weren't > choking first) this is because there are no gasses to keep the heat in. The > only heat there is radiative heat. How do you freeze to death at 200 degrees F? Trust me, freezing wasn't a problem on the moon in full sunlight. > >>>In a world without photosyntisis the non-oxegen forms could still > >>>dominate. > >> > >> How? If they used chemicals for their energy, then the supply of those > >> chemicals better be almost infinite. Most of the chemicals that organisms > >> use these days are recycled by using photosyntesis. Only a small fraction > >>of chemicals is freed by vulcanos, hardly enough to sustain a group of > >>lifeforms. > > > >Depends on the planets and its chemistry. > > I think that if chemicals are not recycled any amount is used up in a > relative short period. (If water and carbondioxide where not recycled by > plants, animal (non photosynthesis) live would very soon die away). But the chemicals are being recycled by the planetary geo-processes, and they have sustained their local populations for a very long time. > >> No, we were apes before we had big brains, and apes are not preditors. > > > >We evolved from chimps, which are predators. (Unlike Gorillas.) Those > >chimps evolved (after some odd twists) into plains preditors and scavengers. > > I've never heard that before, so I'm not certain. > > >We developed that (and primative tool making), before our brains expanded > >much. > > I've seen a TV-series (again :) ) that tried to explain that the human brain > expanded as soon as it began standing up. The reason for that was the > temperature difference between 0.8 metre (on 4 legs) and 1.5 metres (on 2 > legs) above the ground. ------- > One question remains however, why didn't they get a bigger brain while in > the forest before the mountain ridge appeared? Or why didn'tproto apes in cooler climates develop it. Besides, humans are warm blooded. They keep thie brain tissue withing a fraction of a degree of temp. > >> Indeed, most of our brain isn't devoted to anything as far as we know. -- > > > >Actually we do know what all the centers of the brain do, just not how they > >do it. > > Why have I heard so many times that 90% of the brain (or did they mean the > cerebrum) is unused? Thats one of those old saying that have been around forever. Like the idea that aerodynamics says a bee can't fly. Untrue, but so memorable that everyone keeps saying it. > >> --- I > >> meant that a large part is devoted to what you can do with your hands. > >> Suppose you have a large brain, but no hands/legs to make use of it. There > >> would not be any advantage then to have a bigger brain, so it would not > >>evolve. > > > >The biggest section of the human brain evolved to use the eyes, not hands. > > Niether are used in itelegence, that evolved separatly. > > Yes, I'm slowly seeing that size is not the most important factor and that > the largest part of the brain was and is already available. Could it be that > the use of hands and its applications involved a completely new way of > neuron interconnection which had intelligence as convenient side product? > > If I'm not right about this hands->brain connection, then why did we get a > bigger brain? Humans have an odd brain hand trick we retained since we were tree dwelers. It makes certain types of eye hand coordination easier (real important when your jumping for a branch) but humans brains developed long after our bodies and hands were developed. Why did humans develop such powefull minds? Thats a hotly debateed question. Kelly From popserver Fri Feb 2 05:12:34 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["1185" "Fri" "2" "February" "1996" "00:08:56" "-0500" "KellySt@aol.com" "KellySt@aol.com" "<960202000855_212111139@emout09.mail.aol.com>" "23" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout09.mail.aol.com ([198.81.11.24]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA23663 for ; Thu, 1 Feb 1996 21:09:34 -0800 (PST) Received: by emout09.mail.aol.com (8.6.12/8.6.12) id AAA09911; Fri, 2 Feb 1996 00:08:56 -0500 Message-ID: <960202000855_212111139@emout09.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Fri, 2 Feb 1996 00:08:56 -0500 to Timothy van der Linden > Now we found that rations for field troops or explorers weighed about 2.2 >kilos per day (.8 tons per year) and dehydrated could be a lot less. But >over all; 36 tons per person is about 21 years of food mass at their 1.67 >tons per year, or 45 food years at our .8 tons per year. I'm not even >going to bother with freeze dried numbers. We won't want to be out that >long! Even if you assume no soil. The mass is still 14 tons per person. >Which comes to 8.38 year of 1.67 tons per year food years, or 17.5 years at >our .8 tons per year. Then I realized that the farm design required >doubling the internal volume of the hab centrifuge. Which would add another >20 to 230 tons per person! (the latter if you shielded the farm >centrifuge.) >> Would stored food need no protection against radiation? I'm not sure how much and if the food would become radioactive. But if it does, it may need shielding too. << No. Food would only become radioactive if radioactive particals were mixed in with it. Xrays and stuff would cause no perminent change. Thou it would keep longer. Its actually been tested as a food preservative, and works. Kelly From popserver Fri Feb 2 05:17:38 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["411" "Fri" "2" "February" "1996" "00:09:28" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "12" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout07.mail.aol.com ([198.81.11.22]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA23736 for ; Thu, 1 Feb 1996 21:10:24 -0800 (PST) Received: by emout07.mail.aol.com (8.6.12/8.6.12) id AAA20322; Fri, 2 Feb 1996 00:09:28 -0500 Message-ID: <960202000928_212111292@emout07.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@interworld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: I found the food numbers! Date: Fri, 2 Feb 1996 00:09:28 -0500 >> Reply to Kelly >> If we dump our "waste" into the fuel hopper we lose all >> that water that we are going to need unless you plan to >> squeeze all the water out first. I'm not adverse to >> putting unusable waste into the "fuel chain" for the >> ship but lets be sure we don't need it for other >> reasons first, please. Well we could dehydrate it first. Its not like were short of power. ;) Kelly From popserver Fri Feb 2 05:17:39 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1274" "Fri" "2" "February" "1996" "00:09:13" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "33" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id VAA23794 for ; Thu, 1 Feb 1996 21:11:33 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id AAA07296; Fri, 2 Feb 1996 00:09:13 -0500 Message-ID: <960202000912_212110953@mail02.mail.aol.com> From: KellySt@aol.com To: David@interworld.com, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 2 Feb 1996 00:09:13 -0500 Sounds interesting. Keep us informed, and don't hog the glory. ;) Subj: Re: Hands and brains Date: Wed, Jan 31, 1996 9:27 AM EST From: David@interworld.com X-From: David@interworld.com (David Levine) To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Timothy van der Linden wrote: > > To David: > >While social and intelligent > >animals, they're certainly not more intelligent than human > >beings. Perhaps the absolute size of a certain section > >of the brain? Like the cerebellum? > > I think you mean cerebrum (the large brains). Yup, thanks. Hey, all, I've just been contacted by the BBC via email about a television show they want to do this summer about how science fiction becomes science fact. I'm not sure they understand that LIT is a bunch of amateur starship designers, and not actual professors or anything. I'm not sure what to tell them. I've been thinking about just explaining the situation to them, explaining exactly what it is we're doing, and perhaps giving them email addresses of good people to contact whom I've met through LIT (like Zenon, if you'd want?)... From popserver Fri Feb 2 05:53:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1414" "Thu" "1" "February" "1996" "21:47:26" "-0800" "Steve VanDevender" "stevev@efn.org" nil "30" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: stevev@tzadkiel.efn.org Received: from tzadkiel.efn.org (stevev@tzadkiel.efn.org [198.68.17.19]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id VAA26184; Thu, 1 Feb 1996 21:45:10 -0800 (PST) Received: (from stevev@localhost) by tzadkiel.efn.org (8.7.3/8.7.3) id VAA03256; Thu, 1 Feb 1996 21:47:26 -0800 Message-Id: <199602020547.VAA03256@tzadkiel.efn.org> In-Reply-To: <960202000855_212111139@emout09.mail.aol.com> References: <960202000855_212111139@emout09.mail.aol.com> From: Steve VanDevender To: KellySt@aol.com Cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Thu, 1 Feb 1996 21:47:26 -0800 KellySt@aol.com writes: > >> Would stored food need no protection against radiation? I'm not sure how > much and if the food would become radioactive. But if it does, it may need > shielding too. << > > No. Food would only become radioactive if radioactive particals were mixed in > with it. Xrays and stuff would cause no perminent change. Thou it would > keep longer. Its actually been tested as a food preservative, and works. The real answer depends on what kind and what level of radiation the food is exposed to. Alpha particles (helium nuclei) and beta particles (electrons) are unlikely to do any damage to the food, as they will be stopped by the packaging. Energetic ultraviolet and X-rays may ionize atoms in the stored food and produce undesirable chemical changes with high exposure, but won't make the food radioactive. Neutrons or gamma rays could make the food radioactive by interacting with the nuclei of atoms in the food; neutrons can be captured by nuclei to produce radioactive isotopes or transmutation, and gamma rays can induce fission of nuclei. Both types of radiation are likely products of fusion or antimatter reactions. Neutron shielding in fusion reactors is actually a pretty significant problem, as the shielding itself tends to become radioactive. Any high quantity of radiation of the latter two classes is likely to cause degradation of the food over time. From popserver Fri Feb 2 14:45:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["601" "Fri" "2" "February" "1996" "07:23:59" "-0500" "David Levine" "David@interworld.com" nil "20" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id EAA12955 for ; Fri, 2 Feb 1996 04:23:05 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA352; Fri, 2 Feb 1996 07:27:44 -0500 Message-ID: <3112025F.3606@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <960202000842_212110478@mail04.mail.aol.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: KellySt@aol.com CC: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 02 Feb 1996 07:23:59 -0500 KellySt@aol.com wrote: > > To: Timothy van der Linden) > > > > But why do elephants have such big brains (3 to 4 times larger than > humans)? > > They need the nuerons to run their big bodies, which are dozens of times > humans. But what about dinosaurs, small-brained creatures, many of whom had bodies much larger than elephants? I think I've read somewhere that a large portion of their nervous system was distributed... i.e., their spinal cord handled more functions than ours does. So why do elephants have a large brain instead of a distributed nervous system, more like a dinosaurs? David From popserver Fri Feb 2 14:45:19 GMT 1996 X-VM-v5-Data: ([nil nil nil t nil nil nil nil nil] ["601" "Fri" "2" "February" "1996" "07:23:59" "-0500" "David Levine" "David@interworld.com" nil "20" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id EAA12955 for ; Fri, 2 Feb 1996 04:23:05 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA352; Fri, 2 Feb 1996 07:27:44 -0500 Message-ID: <3112025F.3606@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <960202000842_212110478@mail04.mail.aol.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: KellySt@aol.com CC: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 02 Feb 1996 07:23:59 -0500 KellySt@aol.com wrote: > > To: Timothy van der Linden) > > > > But why do elephants have such big brains (3 to 4 times larger than > humans)? > > They need the nuerons to run their big bodies, which are dozens of times > humans. But what about dinosaurs, small-brained creatures, many of whom had bodies much larger than elephants? I think I've read somewhere that a large portion of their nervous system was distributed... i.e., their spinal cord handled more functions than ours does. So why do elephants have a large brain instead of a distributed nervous system, more like a dinosaurs? David From popserver Fri Feb 2 14:45:28 GMT 1996 X-VM-v5-Data: ([nil nil nil t nil nil nil nil nil] ["268" "Fri" "2" "February" "1996" "14:00:15" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "10" "Re: Wrong person?" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA16388 for ; Fri, 2 Feb 1996 05:45:03 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28143 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 14:00:00 +0100 Message-Id: <199602021300.AA28143@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Wrong person? Date: Fri, 02 Feb 1996 14:00:15 +0100 >>>whom I've met through LIT (like Zenon, if you'd want?)... >> >> David, is there a special reason you are addressing Zenon. (Just curious) > >I was under the impression Zenon held a PhD in physics? >Incorrect assumption? Ah, my then assumption was right. Timothy From popserver Fri Feb 2 14:45:29 GMT 1996 X-VM-v5-Data: ([nil nil nil t nil nil nil nil nil] ["2366" "Fri" "2" "February" "1996" "14:00:19" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "50" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA16427 for ; Fri, 2 Feb 1996 05:45:29 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28227 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 14:00:08 +0100 Message-Id: <199602021300.AA28227@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Fri, 02 Feb 1996 14:00:19 +0100 Steve writes: >KellySt@aol.com writes: >> >> Would stored food need no protection against radiation? I'm not sure how >> much and if the food would become radioactive. But if it does, it may need >> shielding too. << >> >> No. Food would only become radioactive if radioactive particals were mixed in >> with it. Xrays and stuff would cause no perminent change. Thou it would >> keep longer. Its actually been tested as a food preservative, and works. > >The real answer depends on what kind and what level of radiation the >food is exposed to. > >Alpha particles (helium nuclei) and beta particles (electrons) are >unlikely to do any damage to the food, as they will be stopped by the >packaging. > >Energetic ultraviolet and X-rays may ionize atoms in the stored food and >produce undesirable chemical changes with high exposure, but won't make >the food radioactive. > >Neutrons or gamma rays could make the food radioactive by interacting >with the nuclei of atoms in the food; neutrons can be captured by nuclei >to produce radioactive isotopes or transmutation, and gamma rays can >induce fission of nuclei. Both types of radiation are likely products >of fusion or antimatter reactions. Neutron shielding in fusion reactors >is actually a pretty significant problem, as the shielding itself tends >to become radioactive. > >Any high quantity of radiation of the latter two classes is likely to >cause degradation of the food over time. Steve thanks for explaining it so clearly, it was indeed the latter that I had in mind. A few years ago I had to do a physics-experiment with small silver-discs. When placed near a radioactive (I think) cesium source they became radioactive too. The specific decay of that silver was rather fast (that was why we used it) so one had to bring it straight from the vault to the experiment, every second counted (because we wanted to determine its decay curve). Of course shortlived radiotopes may not be the main problem, but I'm quite certain that in the forest of possible isotopes one or two will give us a hard time when the food is stored without shielding. As far as I know there are laws for the maximum limits for food radiating levels used to preserve food. I'm not sure though what the reason is. (It could be that it is a precaution for people who have bad food and want to keep it looking OK) Timothy From popserver Fri Feb 2 14:45:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3804" "Fri" "2" "February" "1996" "14:00:29" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "79" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA16528 for ; Fri, 2 Feb 1996 05:46:50 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA28334 (5.67b/IDA-1.5 for ); Fri, 2 Feb 1996 14:00:18 +0100 Message-Id: <199602021300.AA28334@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Fri, 02 Feb 1996 14:00:29 +0100 >What I was going for was that the TV's them selves have changed dramatically >without HDTV. These changes in image quality and relyability were enough >that everyone went out to get a new set. I'm not so sure about that, a lot of people only buy a television because their old one breaks down and the repair cost are almost as high as a new TV-set. Only things like remote control or the number of programmable channels are features that may tempt people to buy a new set while their old one is still working. >I wounder if the internet will wind up becoming part international cable >television? As far as I know all dataflow will be incorporated into a "single" network (eg. ISDN). The communication-protocol is the important thing her, the physical form of the network just has to assure that enough bandwidth is available. So it's more the other way around, cable-tv is becoming part of internet. However it may look the otherway around since cable-companies will become providers of internet. What I mean is that internet already is a multi-purpose network, it can be used for text, images, audio, movies. The thing that people are working at today is to get a protocal that has two parts: a steady-stream fixed bandwith and a burst-stream non-fixed bandwith. The first will can be used for live audio and video while the latter can be used for email, ftp or normal internet use. >Less than that. Computer systems have maintained a 100 fold improvement in >performance per decade for over half a century. Hard to tell how A.I. would >fit into that. We might make a breakthrough (like in my book) and have >everything fall into place in months, or we might stumble along for decades. I go for the few months... >>> Maybe we should make them just smart enough to do >>> the dirty jobs. And use only a few with IQ 1000 to think. > >;) You can't hide forever. Best to come out a deal with things as theyt >happen, not try to lock yourself into a safe past. It's not lock yourself, it's protecting yourself. It's like saying, why not do any kind of genetic experiment, you can't stop it anyway. Of course smart computers are not necessary dangerous, maybe they LIKE to help us out. If they are convinced that we are not just annoying bugs, then the problem may not be that worse. >>> Yes, I found some info about another CRAY having max 1.2 TFLOPS. > >Ok, so we have the electronic brains. Now for the minds! As soon as the structure of the brain and its input is ready the mind will follow automatically. The input is something that a lot of people forget. I think for any brain to start working, the input should be sufficiently high. And if we want a computer that is least likely to kill us and most likely to understand us, we should make its senses similar to ours. I think there is another possibility to control the AI, we let it "live" in a virtual reality, which is created by us. So every action the AI undertakes will not be a real one (so no harm to us), but since we can control it's input it may never know that it is not real. In fact, we don't know that we are real. Of course this depends on what one calls real. For most of us everything that we can measure is real, but there is that stuff where dreams are made of, why not call that real too? In short we are not able to figure out if there is some smart superhuman that is controlling our senses. How can you be sure that you are not in a never ending dream, creating everything and everyone all by yourself? >> Custom circuis are is less efficient to do highly parallel computing than >> neural-circuits. --- > >I was refering to neural net circuts. We alread know how to make them to the >same consentration as standard circuts, but so far they arn't as usfull. Not as useful as we would like... Timothy From popserver Fri Feb 2 14:45:54 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1721" "Fri" "2" "February" "1996" "09:26:09" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "44" "Super computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA18941 for ; Fri, 2 Feb 1996 06:29:19 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA20315; Fri, 2 Feb 96 09:30:38 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI020130; Fri Feb 2 09:27:19 1996 Received: by most (4.1/SMI-4.1) id AA06958; Fri, 2 Feb 96 09:27:16 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma006939; Fri Feb 2 09:26:10 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA22125; Fri, 2 Feb 96 09:26:07 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Kelly Starks x7066 MS 10-39 , Steve VanDevender , KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, bmansur@oc.edu, David@interworld.com Subject: Super computers Date: Fri, 2 Feb 1996 09:26:09 -0500 A tid bit that was forwarded to me. Kelly > > Intel has recently been commissioned to build a teraflops machine. A > teraflop is one trillion floating-point operations per second. In the > passage above Moravec is talking about `10 teraops' which refers to > trillions of `operations' per second. Moravec's notion of an operation is > somewhat complicated. He speaks of `50 bits of surprise for each operation'. > The Intel machine will use more than 9000 Pentium Pro microprocessors > connected in a `two-and-a-half dimensional' mesh. The machine would achieve > roughly one tenth of the benchmark machine Moravec suggests - if he thinks > its operations are flexible enough. > > The URLs http://www.ssd.intel.com/success/hpcwire1.html and > http://www.ssd.intel.com/tflop.html present some background information from > Intel on the teraflops machine project. > > Beyond a teraflop machine (10^12 floating point operations per second) there > is a petaflop machine (10^15 floating point operations per second). There > is a page about `Petaflops Computing' in Wired, February 1996, on page 64. > The URL http://cesdis.gsfc.nasa.gov/petaflops/peta.html has some information > and pointers. > > Of course, even if Moravec is right one must still come up with the right > computer architecture and then one must figure out how to program it (or > figure out how to get it to program itself.) ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Fri Feb 2 14:45:56 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["16508" "Fri" "2" "February" "1996" "09:23:41" "-0500" "Kelly Starks" "kgstar@most.magec.com" nil "372" "Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.magec.com Received: from most.magec.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA19003 for ; Fri, 2 Feb 1996 06:30:18 -0800 (PST) Received: by most.magec.com (4.1/SMI-4.1) id AA20332; Fri, 2 Feb 96 09:30:58 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI019968; Fri Feb 2 09:24:58 1996 Received: by most (4.1/SMI-4.1) id AA06907; Fri, 2 Feb 96 09:24:56 EST Received: from ss4.magec.com(151.168.145.199) by most via smap (V1.5khhunt) id sma006882; Fri Feb 2 09:23:42 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA21967; Fri, 2 Feb 96 09:23:39 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.magec.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Summary Date: Fri, 2 Feb 1996 09:23:41 -0500 At 12:09 AM 2/2/96, KellySt@aol.com wrote: >--------------------- >From: (Timothy van der Linden) >I had to think it over a while, but thanks for reminding: > >>One-way >> * Suicide (explore and die before your time when supplies end) >> * One-way (Enough supplies are shipped to stay in target system > >until natural death) >>>Pros >>The ship need only be designed for a one time, one way flight. This limits >>the technical mission risk and requires less resources. > >Actually there may be an equal or bigger amount of resources. That depends >on if the crew needs to be larger and if more appliances are needed. >If instead of 1E9 kg of fuel you could bring extra crew and appliances that >would probably make a "colonalization" more probable to succeed. Colonization is infeasable anyway without fantastic reserves of people and material. It would take a lot less to return home. >>Lower information return to Earth due to limited baud rates of interstellar >>communication. > >Assuming we are able to create 1E18 Watts I think that bandwidth is minor >problem. Power gets you range, not bandwidth. Since you only have the ability to use the avalible spectrum once. I do worry about bandwidth. >============================================================================== > > >>Round trip (Crew returns to Earth with ship at mission end.) >> >>>Pros >>Simplest option, and one with little likely hood of public objection. > >I'm not sure what you mean with simplest, I think only the part after the >comma is true. Since the flight would be of a definate, ship survivable, length. You wouldn't have as much technical problem with equiping it to survive the crews life span. You wouldn't have to design the systems to function with a declining and incapacitated crew. You only have to make the life suport systems good enough to last 20-40 years with a capable crew. >>It obviously avoids the grisly public relations and crew morale problems of >>a one way mission. > >Seems to me that you use this twice as a pro in this mission. I ment then to cover differnt things, but I suppose it is redundant. >>>cons >>Technically more challenging. Getting a ship to the target starsystem is >>hard enough. Getting it back would make it harder. But this must be >>traded off against the added complexity of a ship capable of supporting its >>crew for the rest of their lives. > >Indeed, but if we are not able to build a small colony during a one-way >mission than the chances are small that we are able to build a complete >power array for a two-way mission. So this means that all power for the >return mission has to come Earth. No, that would only be true if you asumed a beamed power ship, which I don't. Besides, if you do have a beamed power system that can power the ship all the way into another star system (which seems questionable), useing that system again to get the ship out wouldn't add any complexity. Upgrading all the ship systems for an indefinate stay would add complexity. Note that I'm assuming that the flight would have enough resources to support the crew for most of their projected life expectancy. Obviously this wouldn't be a factor in a flight where the crew is expected to kill themselves at the end of the mission >============================================================================== > > >>Pick up and return by follow on flight > >>>cons >>High risk and more complicated. Multiple ship types, and concerns that the >>first ship might be left stranded. > >Also politically less preferable, because the project will take longer and >probably twice the effort. Thats a possibility. It certianly would be politically less likely to be funded allong its entire history. But given that expenses would be spread out over a longer time it might cost less over a given period of time. I'm surprized you objected to this section thou, since its the only option (i.e. assured routine supply flight) that woulkd allow a colony mission? >============================================================================== > > >>Crew constructs equipment for return flight >>This option come up with light/microwave sail craft, beamed power craft, >>and fuel launcher craft. The crew would construct automated duplicates of >>the systems that launched the ship from Sol space. >> >>>Pros >>Would establish launcher facilities in both star systems. Which could >>allowing faster two way flights with specialized fast light ships. > >This assumes that either people stay behind to control and repair the >launcher or that we have AI that is smart enough to keep the thing working >perfectly. >!! This is something we have not discussed before as far as I know !! Sure we have. Months ago. >>The crew might get back faster with their ship using the constructed >>launcher systems for assistance. > >>cons >>If they can't build the equipment, they don't get home. >> >>The construction phase may require so many resources that the first flight >>is devoted just to infrastructure construction. With little or no >>exploration being done in the first mission. This obviously would cool >>public interest and slow down the return of productive information. > >Again, if we are not able to build a small colony during a one-way mission >than the chances are small that we are able to build a complete power array >for a two-way mission. So this means that all power for the return mission >has to come Earth. >Although a power-array may require less different parts than a colony, the >size it much bigger and it uses the same type of machinery that is required >to build a colony. It wouldn't take the same equipment as a colony, nor would it nessisarily be a power array. >Another con is that less time is available for research, unless robots are a >possibility. ?? I said that in that statement? >============================================================================== > > >>Multi-step. (Ship proceeds to other target star after completion of first >>mission, in first starsystem.) >> >>>cons >>Technical feasibility is low since wear and tear on the ship would >>accumulate, dramatically increasing the likelihood of a catastrophic >>failure. >> >>Because of the extremely long flight times with likely technology, the >>mission would take so long as to be undesirable. At some point the ship >>would be superseded by newer faster ships sent straight out from earth, >>decades after its launch. > >Not even undesirable long, but probably too long. Also the conditions should >be the same as a one-way mission and it needs much more energy > >============================================================================== > > >>Multi-generation Succeeding generations of crew continue the mission >> >>>Cons >>The follow on generation(s) in the ship will have no allegiance or >>commitment to the mission or its originators (they, never agreed to >>anything). > >When children grow up in a certain environment, they may like it there. So >it may be very likely that they will continue the mission. There environment wont be that of explorers, but as ship crew. The mission, exploring and returning info to earth, would interfear with that. The history of utopian or riligious colonies in the U.S. suggestes that children and gradchildren don't followe int the focused extreams of the founders. >>The follow on generations would have no hands-on experience with the >>exploration systems they would be expected to use. Or for that matter, any >>experience with planets and starsystems. > >The could be trained just like the initial crew was, the ships computers >will have a large amount of knowledge and learning tools. No, the initial crew could be trained on earth and the solar system, by people who operated the systems in a real environment. That wouldn't be possible on the ship. Especially when the origional, experienced crew grew old and died. > > >> technical political Desirability >> Risk Feasibility risk Feasibility >>------------------------------------------------------------- >>One-way med-low Medium Ex-high Nil Low >>Round trip medium medium low High high >>Pick-up Med-high medium medium medium medium >>Construct ret high med-high medium medium medium >>Multi-step Ex-High. med-low low Medium medium >>Multi-gen Ex-high Low high medium low >>Hibernation high Low medium medium low > >The feasability of a round trip probably depends on the creation of a power >source at TC. I think that if that power source can be created, a colony for >a one-way mission can be build also. That makes the political feasability >much higher. Maybe even higher than a two way mission. I would find it more >exciting to know there people building on a new civilazation than on a back >and forth mission. If the colony could prosper its (political & scientific) >value is much higher than a two way mission. I disagree that a two way mission depends on a beamed power system, nor am I assuming were going to Tau Ceti. Given that we've been at this for over a year and a half and still havent figured out any way to get there, I'm not optimistic. Ignoring that I don't follow your assumption that it would make a one way mission more practical or feasable. A power system would only need to keep working for a few years until the ship gets to the drive cut off point. A self sustaining colony would need to keep working for generations, and require huge amounts of people. Even if a colony was buildable, that doesn't nessisarily make it politically feasable. Your still sending people out to a desolate area for no real proactical benifit (other than scientific, which doesn't require a colony). That would be a political problem. You would NOT be building a new civilization. Your at best seting up a minimally self maintaining base in a harsh and isolated environment. It would have neather the resources of personal or equipment to do much more than that. >Multi-step, Multi-gen and hibernation ships all have the same condition(=a >working ship for >40 years) as a one-way mission so I think they should have >the same political feasability. The difference in political terms, is that it would seem likely that a hibernation system would get the crew back alive (assuming everthing worked). The others condem them to die in space. >The difference between constrution-return and round-trip are not clear since >we haven't defined how(=what energy source) the round-trip makes its return. >So its not clear how the differences in feasability are explained. Rount trip could use a fusion powered ship that mines fuel in the system. Possibly with a fuel launcher construction option. >============================================================================= > >>Mission purpose >>--------------------------------- >>Colonization of planets or moons > >>Isolation from resources. Ores, energy and raw materials are far harder to >>access on a planet than in space. > >If the death-trap could be overcome be medical care, it may be more pleasant >to live on a new (fresh) planet than in a space station. Not likely. We have no reason to asume we'ld find any earth like planets in neighboring star systems. Especiall ones that are so earth like as to be comfortable. (I.E. an Earth like world that was no cooler or wetter than the Sahara or warmer than the antarctic in winter, would still be remarkable.) Certainly if you sticking to the L.I.T. Tau C. flight idea, by definition their were no even vaugly earth like worlds spotted there. >============================================================================= > >>propulsion systems >>--------------------------------- >>Fusion feed from internal fuel sources. >>Staged fusion ship > >I think you shouldn't look at staging the "classical" way. Why not add >hundreds of the same kind of engines and throw them away when not needed any >more. Making many engines of the same type is probably cheaper than a few >that differ in size. Another advantage is that when one becomes defect it's >not a big deal (unless it is an error that each engine has). > >In fact this is just a ship with say 1000 stages. That is "classical" staging? > >A problem with staging is that you throw away your ship, this makes a >two-way mission much harder! Agreed. >>Anti-matter >>Can be destroyed to create tremendous amounts of energy. Releases over a >>hundred times as much power per pound of fuel as a fusion reaction. >> >>Unfortunately, though it releases more power, this power is harder to >>directly use to power the ship. > >This is not certain, the ideas I stated some time ago are only a few and >were considered as most preferred though less easy methods. There does not >have to be a real difference between a fusion or an anti-matter powered >ship. Both can be used as heat-energy sources to accelerate reaction mass. True, but I wasn't expectin to use the fusion power to heat a rockets reation mass. That would threaten to melt the ship quickly. >>It is however far more dangerous to >>handle. If we could synthesize the thousands of tons of antimatter this >>would take. It would have the potential of exploding with a force of >>hundreds of millions of H-bombs. > >This explosion can only happen if there is an equal amount of matter nearby. >I think it may be possible to keep the anti-matter far enough away (in a >large torus for example) Of course even when a minor amount of anti-matter >is "spilled" the ship is likely not to reach its final goal (but does not >have to explode). So while your argument is not completly right, the idea >is. But of course when a major engine of the ship stops working indefinately >this may also be the case. The ship would be a nearby source of mass. A leak might not explode all the fuel in a intermix, but a tiny amount would still go off like a H-bomb. >>Future tech >> >>The engineering and science we have now and assume we will have in the >>future will change. Fusion, fission, relativity, quantum mechanics, and a >>host of other basics of current physics; all were discovered within the >>last hundred years. We can conservatively expect physics to have changed >>far more in the next hundred years, then it did in the last hundred years. >>What technologies that age will have on hand are impossible to guess. They >>could have matter conversion, hyperlight drives, new understandings of >>inertia and kinetic energy, or all those and far more. Any of these would >>dramatically effect our ability to travel between the stars. So even >>though we can't come up with any practical ideas for exploring the stars >>now, we can be sure our descendants will find it far easier than we >>imagine. > >FTL is a principle that has been withstanding many experiments to unprove >it. Chances are small that FTL will become possible in the next century (if >at all). Small but not impossible. It seems ftl is possible, but we know of no way to do it with any realistic physical system, much less a buildable one. But then we would have said that about space travel a couple of cventuries ago. It definatly requires some new physics (as opposed to engineering) tricks. Then again, without it star travel beyond the nearest stars will never be practical. >========================================================================== > >A possible disavantage for a two way trip is that the crew has to live a >long time in a ship. If it is a disadvantage depends on the size of the >ship, if this is a disadvantage for a one way mission depends on the >possibility to extend the ship when at TC. > >Timothy I don't follow that last bit. Presumably a one way flight could construct a larger space platform for living quarters. But if they could construct anything that extensive, they could build a way to get home. So presumably eiather way they are stuck in the ship. Just for a lot longer if they aren't coming home. Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Sat Feb 3 04:02:07 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["496" "Sat" "3" "February" "1996" "00:46:17" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "15" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA02099 for ; Fri, 2 Feb 1996 15:45:17 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15497 (5.67b/IDA-1.5 for ); Sat, 3 Feb 1996 00:46:05 +0100 Message-Id: <199602022346.AA15497@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sat, 03 Feb 1996 00:46:17 +0100 To David: >But what about dinosaurs, small-brained creatures, >many of whom had bodies much larger than elephants? >I think I've read somewhere that a large portion >of their nervous system was distributed... i.e., >their spinal cord handled more functions than ours >does. So why do elephants have a large brain >instead of a distributed nervous system, more >like a dinosaurs? Maybe they had a smaller brain because they were (coldblooded?) reptiles instead of warmblooded mammals. Timothy From popserver Sat Feb 3 04:02:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4641" "Sat" "3" "February" "1996" "00:46:08" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "108" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA04816 for ; Fri, 2 Feb 1996 16:18:27 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15488 (5.67b/IDA-1.5); Sat, 3 Feb 1996 00:45:43 +0100 Message-Id: <199602022345.AA15488@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sat, 03 Feb 1996 00:46:08 +0100 To Kelly: >> But why do elephants have such big brains (3 to 4 times larger than >humans)? > >They need the nuerons to run their big bodies, which are dozens of times >humans. Are you sure or are you guessing? The story that David wrote, I had heard before. It was the reason why I thought (before I read otherwise) that an elephant (and a dolphin) had a small brain too. Looking at this after discussing it, a possible explanation may be that the brain-cells are much bigger. This may also be the case for dolphins. So when saying the absolute size, I should have said the number of neurons. I don't have any confirming data however. I'm going to search for some more data about this. >> >automate systems will work well and productivly. Which is why all large >> >manufacturing industries use them. >> >> But that means that much less people can do the job > >Yes. So if you go on a few centuries, only a few people have to work. This is where I was going to. >> It's keeping the heat in: Greenhouse gasses are more opaque planetary >> radiation than for solar radiation. Solar radiation is what directly comes >> from the Sun and planetary radiation is > >I know the theory, I also know their is no data to support it. Of course I don't have the hands on an experiment that proved it but I find it very hard to believe that no one has tried to figure out to what kind of radiation the so called greenhouse gasses are most opaque. This very simple experiment would show the proof or rebuttal. >It is also argued if the earth is getting warmer or cooler. NASA went back >over 25-30 years of satelihgt scans. They could have detected a change as >small as 1/5th the smallest variation predicted by any of the green house >theories. They didn't find it. Longer term arcio-climatology studies have >shown a cooling since the mid 1800, a warming from the 1700, and a long term >cooling over the last 800 years. Did these images show there was no temperature increase or did they show that there was no increase due to the so called greenhouse effect. If you mean the latter, how can they distinguish between normal and greenhouse deviations? >> To that I agree, but as long the greenhouse effect is not too large the >> temperatures will not become so high that no live can exist. At the >> light-side of the moon you will freeze to death (assuming you weren't >> choking first) this is because there are no gasses to keep the heat in. The >> only heat there is radiative heat. > >How do you freeze to death at 200 degrees F? Trust me, freezing wasn't a >problem on the moon in full sunlight. Yes, that is radiative heat, not convective. So everything that is in the shadow is much colder. I assume that if you where standing with your back to the Sun than your belly would freeze. >> I think that if chemicals are not recycled any amount is used up in a >> relative short period. (If water and carbondioxide where not recycled by >> plants, animal (non photosynthesis) live would very soon die away). > >But the chemicals are being recycled by the planetary geo-processes, and they >have sustained their local populations for a very long time. Yes, but the chances for evolution are not very big in a small (local) area where the climate is relatively stable. Higher evolutionized animals would not occur due to serious inbreading. >> I've seen a TV-series (again :) ) that tried to explain that the human >brain >> expanded as soon as it began standing up. The reason for that was the >> temperature difference between 0.8 metre (on 4 legs) and 1.5 metres (on 2 >> legs) above the ground. ------- >> One question remains however, why didn't they get a bigger brain while in >> the forest before the mountain ridge appeared? > >Or why didn'tproto apes in cooler climates develop it. Ah, I think I know, they had a live that was too easy, so there was no advantage of being smart. The apes on the rather dry and hot savannas had to do more for their food than just sitting on a branch. >Besides, humans are >warm blooded. They keep thie brain tissue withing a fraction of a degree of >temp. But it is much harder to cool in higher temperatures. >Humans have an odd brain hand trick we retained since we were tree dwelers. > It makes certain types of eye hand coordination easier (real important when >your jumping for a branch) but humans brains developed long after our bodies >and hands were developed. So you do agree (to a certain degree) that there is a more than normal connection between hand and brain? >Why did humans develop such powefull minds? Thats a hotly debateed question. Yes, I noticed ;) Tim From popserver Sat Feb 3 04:02:21 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10392" "Sat" "3" "February" "1996" "00:46:20" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "217" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA04896 for ; Fri, 2 Feb 1996 16:19:42 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15501 (5.67b/IDA-1.5); Sat, 3 Feb 1996 00:46:09 +0100 Message-Id: <199602022346.AA15501@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Sat, 03 Feb 1996 00:46:20 +0100 >>>Lower information return to Earth due to limited baud rates of interstellar >>>communication. >> >>Assuming we are able to create 1E18 Watts I think that bandwidth is minor >>problem. > >Power gets you range, not bandwidth. Since you only have the ability to >use the avalible spectrum once. I do worry about bandwidth. I assumed these bands where unusable because of interstellar noise, but since that does not seem to be the case, I ask you which interstellar bands are not usable and why? I cannot believe that the bandwith is too small, if necessary we may be able to build X-ray transmitters. ============================================================================== >>>>cons >>>Technically more challenging. Getting a ship to the target starsystem is >>>hard enough. Getting it back would make it harder. But this must be >>>traded off against the added complexity of a ship capable of supporting its >>>crew for the rest of their lives. >> >>Indeed, but if we are not able to build a small colony during a one-way >>mission than the chances are small that we are able to build a complete >>power array for a two-way mission. So this means that all power for the >>return mission has to come Earth. > >No, that would only be true if you asumed a beamed power ship, which I >don't. Besides, if you do have a beamed power system that can power the >ship all the way into another star system (which seems questionable), >useing that system again to get the ship out wouldn't add any complexity. >Upgrading all the ship systems for an indefinate stay would add complexity. It would have been easier if you wrote what kind of propulsion you assumed. Since you are not assuming a beamed power ship, I assume you use a fusion powered ship so distances are less than 6 ly. This limits the amount of possible stars even more, I would see that as a cerious disadvantage. ============================================================================== >>Also politically less preferable, because the project will take longer and >>probably twice the effort. > >Thats a possibility. It certianly would be politically less likely to be >funded allong its entire history. But given that expenses would be spread >out over a longer time it might cost less over a given period of time. > >I'm surprized you objected to this section thou, since its the only option >(i.e. assured routine supply flight) that woulkd allow a colony mission? I'm just being consequent. ============================================================================== >>>Crew constructs equipment for return flight >>This assumes that either people stay behind to control and repair the >>launcher or that we have AI that is smart enough to keep the thing working >>perfectly. >>!! This is something we have not discussed before as far as I know !! > >Sure we have. Months ago. Then what was the conclusion, I can't remember it? Saying that it only has to work for 20 years, is not enough since the pro was that it had to make a two way trip easier. >It wouldn't take the same equipment as a colony, nor would it nessisarily >be a power array. If you are planning on building a big mirror, I think you need a lot of machinery and crew to operate it. To build anything like a mirror of several kilmetres, you need ore-extracters, refineries, transporters etc. The amount in which they are needed exceeds by far that what is needed for building a colony. The mirror may look easy to build but I'm sure that almost everything you need for a colony you also need for building a mirror. The only thing you would not need is a farm. ============================================================================== >>>Multi-generation Succeeding generations of crew continue the mission >There environment wont be that of explorers, but as ship crew. The >mission, exploring and returning info to earth, would interfear with that. >The history of utopian or riligious colonies in the U.S. suggestes that >children and gradchildren don't followe int the focused extreams of the >founders. We are not talking about religious groups. These groups often have the tendency to cling to an utopia. Often they use stringent rules based on the belief of the leader, everyone trying to disobey is punished. On an explorer ship people can have a more democratic way of living. Also not everybody needs to be an explorer, there are people that need to do other jobs as well. >No, the initial crew could be trained on earth and the solar system, by >people who operated the systems in a real environment. That wouldn't be >possible on the ship. Especially when the origional, experienced crew grew >old and died. On a multi-gen ship there will also be a scientific crew, they are explorers. If then need some practical experience, they will have all the time they need. Simulators for shuttles and vehicles could do a great job helping them. >I disagree that a two way mission depends on a beamed power system, nor am >I assuming were going to Tau Ceti. Given that we've been at this for over >a year and a half and still havent figured out any way to get there, I'm >not optimistic. It would be nice if you wrote that somewhere in this draft though. >Ignoring that I don't follow your assumption that it would make a one way >mission more practical or feasable. A power system would only need to keep >working for a few years until the ship gets to the drive cut off point. It's a big risk trusting your live to a automated system on which you would have no control. A single programming error can shut down the power source and there would be no one to turn it on again. >A self sustaining colony would need to keep working for generations, and >require huge amounts of people. Even if a colony was buildable, that >doesn't nessisarily make it politically feasable. Your still sending >people out to a desolate area for no real proactical benifit (other than >scientific, which doesn't require a colony). With colony I don't necessary mean a planet based one, a scientific mission that would really "get into" the planets would need much more than 10 years, so they would like a place to live also. >>Multi-step, Multi-gen and hibernation ships all have the same condition(=a >>working ship for >40 years) as a one-way mission so I think they should have >>the same political feasability. > >The difference in political terms, is that it would seem likely that a >hibernation system would get the crew back alive (assuming everthing >worked). The others condem them to die in space. You are constantly saying most things will break down within 25 to 35 years. If the largest part of the crew is in hybernation, they will have an even harder job to get things fixed in time. So if I want to follow that, hibernation is even doomed more than a one-way mission. And of course this assumes that hibernation will work, I personally would see a bigger possibility of an anti-matter drive than for hibernation. >>The difference between constrution-return and round-trip are not clear since >>we haven't defined how(=what energy source) the round-trip makes its return. >>So its not clear how the differences in feasability are explained. > >Rount trip could use a fusion powered ship that mines fuel in the system. >Possibly with a fuel launcher construction option. Of course we need to know if the fuel we need can be found and mined easely. Although hydrogen will be present, it may not be as concentrated as we like. ============================================================================= >Not likely. We have no reason to asume we'ld find any earth like planets >in neighboring star systems. Especiall ones that are so earth like as to >be comfortable. (I.E. an Earth like world that was no cooler or wetter >than the Sahara or warmer than the antarctic in winter, would still be >remarkable.) Certainly if you sticking to the L.I.T. Tau C. flight idea, >by definition their were no even vaugly earth like worlds spotted there. Then why are we going, one of the main LIT objectives was that there was a strong evidence of life in the system we would explore. When there is life it will almost certainly have some acceptable temperature. ============================================================================= >>A problem with staging is that you throw away your ship, this makes a >>two-way mission much harder! > >Agreed. So, do you know how to solve it without having a big industry at the remote end of the trip? >>This is not certain, the ideas I stated some time ago are only a few and >>were considered as most preferred though less easy methods. There does not >>have to be a real difference between a fusion or an anti-matter powered >>ship. Both can be used as heat-energy sources to accelerate reaction mass. > >True, but I wasn't expectin to use the fusion power to heat a rockets >reation mass. That would threaten to melt the ship quickly. How where you going to use that heat then? Does it matter that much if you are first tranforming the heat into electricity? >>FTL is a principle that has been withstanding many experiments to unprove >>it. Chances are small that FTL will become possible in the next century (if >>at all). > >Small but not impossible. It seems ftl is possible, but we know of no way >to do it with any realistic physical system, much less a buildable one. >But then we would have said that about space travel a couple of cventuries >ago. It definatly requires some new physics (as opposed to engineering) >tricks. Then again, without it star travel beyond the nearest stars will >never be practical. Why does it seem that ftl is possible, I've never seen a serious article that stated to have found a way to make a signal travel faster than the speed of light. Even not in tunneling! ========================================================================== >I don't follow that last bit. Presumably a one way flight could construct >a larger space platform for living quarters. But if they could construct >anything that extensive, they could build a way to get home. So presumably >eiather way they are stuck in the ship. Just for a lot longer if they >aren't coming home. Indeed they could, but maybe they would not want to stay any longer in a small ship. Of course this depends on the duration of the trip. Timothy From popserver Sat Feb 3 04:03:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["738" "Fri" "2" "February" "1996" "17:33:11" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "19" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA11265 for ; Fri, 2 Feb 1996 17:38:55 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts2-p59.wolfenet.com [204.157.98.177]) by wolfe.net (8.7.3/8.7) with SMTP id RAA26543; Fri, 2 Feb 1996 17:33:11 -0800 (PST) Message-Id: <199602030133.RAA26543@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Hands and brains Date: Fri, 2 Feb 1996 17:33:11 -0800 (PST) >To David: > >>But what about dinosaurs, small-brained creatures, >>many of whom had bodies much larger than elephants? >>I think I've read somewhere that a large portion >>of their nervous system was distributed... i.e., >>their spinal cord handled more functions than ours >>does. So why do elephants have a large brain >>instead of a distributed nervous system, more >>like a dinosaurs? > >Maybe they had a smaller brain because they were (coldblooded?) reptiles >instead of warmblooded mammals. This is in great debate right now. Depends on which camp you are in. Dr Bakker beleives they were mostly warm blooded based partly on the care of young and other factors I can't remember right now. I tend to lean twords his beliefs. Ric From popserver Sat Feb 3 21:45:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["713" "Sat" "3" "February" "1996" "15:44:31" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "19" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id GAA14485 for ; Sat, 3 Feb 1996 06:43:07 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA18432 (5.67b/IDA-1.5 for ); Sat, 3 Feb 1996 15:44:04 +0100 Message-Id: <199602031444.AA18432@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sat, 03 Feb 1996 15:44:31 +0100 Reply to Ric: >>Maybe they had a smaller brain because they were (coldblooded?) reptiles >>instead of warmblooded mammals. > >This is in great debate right now. Depends on which camp you are in. Dr >Bakker beleives they were mostly warm blooded based partly on the care of >young and other factors I can't remember right now. I tend to lean twords >his beliefs. >Ric They did lay eggs, I think? And they did not have hairs like most mammals. Did dinosaurs have scales like reptiles? Maybe the dinosaurs were somewhere in the middle, due to their size the couldn't rely on the Sun alone to heat up. For bigger animals it would also be easier to keep the heat in due to the better volume:surface ratio. Timothy From popserver Sat Feb 3 21:46:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["725" "Sat" "3" "February" "1996" "14:16:50" "-0500" "David Levine" "David@interworld.com" nil "23" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id LAA29153 for ; Sat, 3 Feb 1996 11:16:11 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA492; Sat, 3 Feb 1996 14:21:14 -0500 Message-ID: <3113B4A2.41BF@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0b5 (WinNT; I) MIME-Version: 1.0 References: <199602031444.AA18432@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sat, 03 Feb 1996 14:16:50 -0500 Timothy van der Linden wrote: > > Reply to Ric: > > >>Maybe they had a smaller brain because they were (coldblooded?) reptiles > >>instead of warmblooded mammals. > > > >This is in great debate right now. Depends on which camp you are in. Dr > >Bakker beleives they were mostly warm blooded based partly on the care of > >young and other factors I can't remember right now. I tend to lean twords > >his beliefs. > >Ric > > They did lay eggs, I think? And they did not have hairs like most mammals. > Did dinosaurs have scales like reptiles? > But Ric is just saying that they may have been warm blooded - he's not saying they may have been mammals. Birds, for instance, are warm blooded, but they're not mammals. David From popserver Sat Feb 3 21:46:48 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["933" "Sat" "3" "February" "1996" "11:40:16" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "29" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id LAA01028 for ; Sat, 3 Feb 1996 11:38:35 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts3-p10.wolfenet.com [204.157.98.192]) by wolfe.net (8.7.3/8.7) with SMTP id LAA18588; Sat, 3 Feb 1996 11:40:16 -0800 (PST) Message-Id: <199602031940.LAA18588@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Hands and brains Date: Sat, 3 Feb 1996 11:40:16 -0800 (PST) >Timothy van der Linden wrote: >> >> Reply to Ric: >> >> >>Maybe they had a smaller brain because they were (coldblooded?) reptiles >> >>instead of warmblooded mammals. >> > >> >This is in great debate right now. Depends on which camp you are in. Dr >> >Bakker beleives they were mostly warm blooded based partly on the care of >> >young and other factors I can't remember right now. I tend to lean twords >> >his beliefs. >> >Ric >> >> They did lay eggs, I think? And they did not have hairs like most mammals. >> Did dinosaurs have scales like reptiles? >> > >But Ric is just saying that they may have been warm >blooded - he's not saying they may have been mammals. >Birds, for instance, are warm blooded, but they're >not mammals. > >David Anatomicly (?) dinosaurs are 99%+ built like birds, especially the carnivors. The way the legs work, Feathers are really scales, the need for grining stones in the gullet. etc.... > > From popserver Sat Feb 3 23:25:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1755" "Sun" "4" "February" "1996" "00:21:53" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "42" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id PAA14073 for ; Sat, 3 Feb 1996 15:20:34 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA10190 (5.67b/IDA-1.5 for ); Sun, 4 Feb 1996 00:21:42 +0100 Message-Id: <199602032321.AA10190@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sun, 04 Feb 1996 00:21:53 +0100 Reply to: David and Ric >>> >>Maybe they had a smaller brain because they were (coldblooded?) reptiles >>> >>instead of warmblooded mammals. >>> > >>> >This is in great debate right now. Depends on which camp you are in. Dr >>> >Bakker beleives they were mostly warm blooded based partly on the care of >>> >young and other factors I can't remember right now. I tend to lean twords >>> >his beliefs. >>> >Ric >>> >>> They did lay eggs, I think? And they did not have hairs like most mammals. >>> Did dinosaurs have scales like reptiles? >>> >> >>But Ric is just saying that they may have been warm >>blooded - he's not saying they may have been mammals. >>Birds, for instance, are warm blooded, but they're >>not mammals. I was not argueing that, I just wanted to show a way why they could have been warmblooded while having a small brain. For thay way it was important to show they where reptiles first. Since reptiles are originally coldblooded, I figured that if they became warmblooded, it would only be logical due to their increased size. So that means they were shifting from cold- to warmblooded and not that they had been warmblooded all the time. So then their smaller brain would have been a remainder of earlier coldblooded days, where it would have been more difficult to keep a larger brain working. (Mammals, birds and reptiles are the members of the vertebrates. So that implies that they have some similarities.) >Anatomicly (?) dinosaurs are 99%+ built like birds, especially the >carnivors. The way the legs work, Feathers are really scales, the need for >grining stones in the gullet. etc.... I didn't know that birds used sand? in their "stomach/gullet". But in what way do bird and mammal legs differ from reptiles? Timothy From popserver Wed Feb 7 21:27:42 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["199" "Wed" "7" "February" "1996" "18:16:56" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "14" "Who am I?" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA06906 for ; Wed, 7 Feb 1996 09:15:37 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA03890 (5.67b/IDA-1.5 for ); Wed, 7 Feb 1996 18:16:48 +0100 Message-Id: <199602071716.AA03890@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Who am I? Date: Wed, 07 Feb 1996 18:16:56 +0100 >I think therefore I am. So at least I know I exist. > >Brian Mansur No, no: I think, therefore you are... Now I only wonder: What am I? Timothy P.S. Did you carbon copy this only to Kelly? From popserver Thu Feb 8 07:48:10 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["268" "Wed" "7" "February" "1996" "17:09:03" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "7" "Where is everyone" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id VAA14247 for ; Wed, 7 Feb 1996 21:55:24 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts3-p08.wolfenet.com [204.157.98.190]) by wolfe.net (8.7.3/8.7) with SMTP id RAA29430; Wed, 7 Feb 1996 17:09:03 -0800 (PST) Message-Id: <199602080109.RAA29430@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Where is everyone Date: Wed, 7 Feb 1996 17:09:03 -0800 (PST) Just wondering what has happened. I haven't seen any messages for a week now and I am begining to think I have missed some importent infomation. Do we have a newsletter again? Is the LIT web site up and folks are posting there? I'm going into LIT withdrawl. :-) Ric From popserver Thu Feb 8 19:07:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["262" "Thu" "8" "February" "1996" "09:32:00" "PST" "Brian Mansur" "bmansur@oc.edu" nil "11" "RE: REPLY ALL" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: bmansur@oc.edu Received: from einstein.oc.edu (DNS2.OC.EDU [205.143.216.15]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id HAA15244 for ; Thu, 8 Feb 1996 07:34:16 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA07665; Thu, 8 Feb 1996 09:31:19 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <311A3353@mainpobox.oc.edu>; Thu, 08 Feb 96 09:30:59 PST Message-Id: <311A3353@mainpobox.oc.edu> Encoding: 12 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: bmansur , David , hous0042 , jim , KellySt , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: RE: REPLY ALL Date: Thu, 08 Feb 96 09:32:00 PST ---------- From: Brian V. Mansur To: KellySt; stevev; jim; zkulpa; hous0042; rddesign; David; bmansur Subject: replying to everyone Date: Saturday, Feburary 8, 1996 9:30 AM I just discovered the REPLY ALL button on my e-mail program! Now I can die happy. From popserver Thu Feb 8 19:07:33 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["588" "Thu" "8" "February" "1996" "10:13:16" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "22" "RE: REPLY ALL" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA18015 for ; Thu, 8 Feb 1996 08:14:49 -0800 (PST) Received: by maroon.tc.umn.edu; Thu, 8 Feb 96 10:13:17 -0600 In-Reply-To: <311A3353@mainpobox.oc.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Brian Mansur cc: bmansur , David , jim , KellySt , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: RE: REPLY ALL Date: Thu, 8 Feb 1996 10:13:16 -0600 (CST) On Thu, 8 Feb 1996, Brian Mansur wrote: > > I just discovered the REPLY ALL button on my e-mail program! Now I can die > happy. Gee Brian, when I reply to someone, my mail program asks me two questions. 1) include original message in reply y/n 2) reply to all recipients y/n to:all Re: my participation I've had a rough couple of weeks, I've been following along, but not responding much. rest assured, that I have not started the trip without you Kevin in MN Where I was walking around in short sleeves yesterday because the temp had risen to a balmy 35 F. :) From popserver Fri Feb 9 02:06:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1986" "Thu" "8" "February" "1996" "20:30:21" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "48" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail06.mail.aol.com (mail06.mail.aol.com [152.163.172.108]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA08869 for ; Thu, 8 Feb 1996 17:32:28 -0800 (PST) Received: by mail06.mail.aol.com (8.6.12/8.6.12) id UAA09154; Thu, 8 Feb 1996 20:30:21 -0500 Message-ID: <960208203019_139506541@mail06.mail.aol.com> From: KellySt@aol.com To: stevev@efn.org cc: T.L.G.vanderLinden@student.utwente.nl, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Thu, 8 Feb 1996 20:30:21 -0500 stevev@efn.org (Steve VanDevender) > > KellySt@aol.com writes: > > >> Would stored food need no protection against radiation? I'm not sure how > > much and if the food would become radioactive. But if it does, it may need > > shielding too. << > > > > No. Food would only become radioactive if radioactive particals were mixed in > > with it. Xrays and stuff would cause no perminent change. Thou it would > > keep longer. Its actually been tested as a food preservative, and works. > > The real answer depends on what kind and what level of radiation the > food is exposed to. > > Alpha particles (helium nuclei) and beta particles (electrons) are > unlikely to do any damage to the food, as they will be stopped by the > packaging. > > Energetic ultraviolet and X-rays may ionize atoms in the stored food and > produce undesirable chemical changes with high exposure, but won't make > the food radioactive. > > Neutrons or gamma rays could make the food radioactive by interacting > with the nuclei of atoms in the food; neutrons can be captured by nuclei > to produce radioactive isotopes or transmutation, and gamma rays can > induce fission of nuclei. Both types of radiation are likely products > of fusion or antimatter reactions. Neutron shielding in fusion reactors > is actually a pretty significant problem, as the shielding itself tends > to become radioactive. > > Any high quantity of radiation of the latter two classes is likely to > cause degradation of the food over time. Unless of course the fusion fuel you specified doesn't produce neutrons. Off hand I can't think of a Gama source on the ship, unles we use antimater. In that case we have a very hard radiation problem in general. We might have more problems with cosmic radiation, especially on fast ships. But given the tolerance of the food vs the human crew I don't, think, it will be a problem. Certainly less than with a farm where the food has to be kept healthy to grow. Kelly From popserver Fri Feb 9 02:06:56 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1100" "Thu" "8" "February" "1996" "20:30:31" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "30" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA08924 for ; Thu, 8 Feb 1996 17:33:06 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id UAA10030; Thu, 8 Feb 1996 20:30:31 -0500 Message-ID: <960208203030_139506704@emout06.mail.aol.com> From: KellySt@aol.com To: David@interworld.com cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Thu, 8 Feb 1996 20:30:31 -0500 to: David@interworld.com (David Levine) > KellySt@aol.com wrote: > > > > To: Timothy van der Linden) > > > > > > But why do elephants have such big brains (3 to 4 times larger than > > humans)? > > > > They need the nuerons to run their big bodies, which are dozens of times > > humans. > > But what about dinosaurs, small-brained creatures, > many of whom had bodies much larger than elephants? > I think I've read somewhere that a large portion > of their nervous system was distributed... i.e., > their spinal cord handled more functions than ours > does. So why do elephants have a large brain > instead of a distributed nervous system, more > like a dinosaurs? > > David Hum, don't know. Then again how intelegent were they, and how heavy were their brains (or spinal cords in this case). I'ld guess they were very stupid, so they would need a preportionally smaller brain. Where as an elephant is fairly cleaver (say compared to a horse or something) so it needed a preportionally bigger brain then a Bronto. (Naturally I have extensive field experence with dinosaurs. ;) ) Kelly From popserver Fri Feb 9 02:06:59 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["14622" "Thu" "8" "February" "1996" "20:31:20" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "319" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA08981 for ; Thu, 8 Feb 1996 17:33:35 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id UAA05160; Thu, 8 Feb 1996 20:31:20 -0500 Message-ID: <960208203119_139507411@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Thu, 8 Feb 1996 20:31:20 -0500 to: Timothy van der Linden) > > >>>Lower information return to Earth due to limited baud rates of interstellar > >>>communication. > >> > >>Assuming we are able to create 1E18 Watts I think that bandwidth is minor > >>problem. > > > >Power gets you range, not bandwidth. Since you only have the ability to > >use the avalible spectrum once. I do worry about bandwidth. > > I assumed these bands where unusable because of interstellar noise, but > since that does not seem to be the case, I ask you which interstellar bands > are not usable and why? I cannot believe that the bandwith is too small, if > necessary we may be able to build X-ray transmitters. I'm just saying that there is a limit to the amount of information that can be transmitted inteligably over interstellar distences even is your playing with all the usable spectrum. Obviously the local star(s) will drown out most of the frequency bands, given that earth scopes will be looking straight at it. So we will eiather have to make due with that stars quiet bands, use incredible amounts of power (you really want to out shout a star?), and use a lot of low bouad and error correction to make up for interfearence. ============================================================================== > >>>>cons > >>>Technically more challenging. Getting a ship to the target starsystem is > >>>hard enough. Getting it back would make it harder. But this must be > >>>traded off against the added complexity of a ship capable of supporting its > >>>crew for the rest of their lives. > >> > >>Indeed, but if we are not able to build a small colony during a one-way > >>mission than the chances are small that we are able to build a complete > >>power array for a two-way mission. So this means that all power for the > >>return mission has to come Earth. > > > >No, that would only be true if you asumed a beamed power ship, which I > >don't. Besides, if you do have a beamed power system that can power the > >ship all the way into another star system (which seems questionable), > >useing that system again to get the ship out wouldn't add any complexity. > >Upgrading all the ship systems for an indefinate stay would add complexity. > > It would have been easier if you wrote what kind of propulsion you assumed. > Since you are not assuming a beamed power ship, I assume you use a fusion > powered ship so distances are less than 6 ly. This limits the amount of > possible stars even more, I would see that as a cerious disadvantage. I was trying to not assume any system or technology but to phrase it a genarically as possible. If the ship is limited to a flight duration of so many years. Its range varies with its speed. ============================================================================== > > >>Also politically less preferable, because the project will take longer and > >>probably twice the effort. > > > >Thats a possibility. It certianly would be politically less likely to be > >funded allong its entire history. But given that expenses would be spread > >out over a longer time it might cost less over a given period of time. > > > >I'm surprized you objected to this section thou, since its the only option > >(i.e. assured routine supply flight) that woulkd allow a colony mission? > > I'm just being consequent. Consequent? Is that the word you ment? ============================================================================== > > >>>Crew constructs equipment for return flight > > >>This assumes that either people stay behind to control and repair the > >>launcher or that we have AI that is smart enough to keep the thing working > >>perfectly. > >>!! This is something we have not discussed before as far as I know !! > > > >Sure we have. Months ago. > > Then what was the conclusion, I can't remember it? A simple system like a fuel launcher that only has to work for a couple months every few deacdes should be able to be automated once its set up. And making redundant copies will assure acceptable relyability. Also the first thing eveyone does when entering the system is repair the fuel launcher. > Saying that it only has to work for 20 years, is not enough since the pro > was that it had to make a two way trip easier. > > >It wouldn't take the same equipment as a colony, nor would it nessisarily > >be a power array. > > If you are planning on building a big mirror, I think you need a lot of > machinery and crew to operate it. To build anything like a mirror of several > kilmetres, you need ore-extracters, refineries, transporters etc. The amount > in which they are needed exceeds by far that what is needed for building a > colony. The mirror may look easy to build but I'm sure that almost > everything you need for a colony you also need for building a mirror. The > only thing you would not need is a farm. I wasn't building a mirror (what i the hell would it be for anyway?), and colonies need air and water recyclers, housing for humans, furniture, hospitals, and a lot of other things that a automated platform wouldn't need. ============================================================================== > > >>>Multi-generation Succeeding generations of crew continue the mission > > >There environment wont be that of explorers, but as ship crew. The > >mission, exploring and returning info to earth, would interfear with that. > >The history of utopian or riligious colonies in the U.S. suggestes that > >children and gradchildren don't followe int the focused extreams of the > >founders. > > We are not talking about religious groups. --- Well obviously only a very 'focused' group of beleavers are going to condem themselves to perminent imprisionment for a multi-gen cause. > --- These groups often have the > tendency to cling to an utopia. Often they use stringent rules based > on the belief of the leader, everyone trying to disobey is punished. > On an explorer ship people can have a more democratic way of living. > Also not everybody needs to be an explorer, there are people that > need to do other jobs as well. > > >No, the initial crew could be trained on earth and the solar system, by > >people who operated the systems in a real environment. That wouldn't be > >possible on the ship. Especially when the origional, experienced crew grew > >old and died. > > On a multi-gen ship there will also be a scientific crew, they are > explorers. If then need some practical experience, they will have all the > time they need. Simulators for shuttles and vehicles could do a great job > helping them. You can't simulate exploring planets in the confines of a vitual reality simulator, nor can you learn everything about fliying high performance aircraft without flying them. None of which can be done completly in a sim. In a multi-gen crew. Nothing anout exploration, not even seeing a real sky or horizon would be familure to them. > >I disagree that a two way mission depends on a beamed power system, nor am > >I assuming were going to Tau Ceti. Given that we've been at this for over > >a year and a half and still havent figured out any way to get there, I'm > >not optimistic. > > It would be nice if you wrote that somewhere in this draft though. I suppose we will need a summarry of all the drive systems we considered. > >Ignoring that I don't follow your assumption that it would make a one way > >mission more practical or feasable. A power system would only need to keep > >working for a few years until the ship gets to the drive cut off point. > > It's a big risk trusting your live to a automated system on which you would > have no control. A single programming error can shut down the power source > and there would be no one to turn it on again. Compared to the dangers of a colony, thats trivial. > >A self sustaining colony would need to keep working for generations, and > >require huge amounts of people. Even if a colony was buildable, that > >doesn't nessisarily make it politically feasable. Your still sending > >people out to a desolate area for no real proactical benifit (other than > >scientific, which doesn't require a colony). > > With colony I don't necessary mean a planet based one, a scientific > mission that would really "get into" the planets would need much > more than 10 years, so they would like a place to live also. > > >>Multi-step, Multi-gen and hibernation ships all have the same condition(=a > >>working ship for >40 years) as a one-way mission so I think they should have > >>the same political feasability. > > > >The difference in political terms, is that it would seem likely that a > >hibernation system would get the crew back alive (assuming everthing > >worked). The others condem them to die in space. > > You are constantly saying most things will break down within 25 to 35 years. > If the largest part of the crew is in hybernation, they will have an even > harder job to get things fixed in time. So if I want to follow that, > hibernation is even doomed more than a one-way mission. And of course this > assumes that hibernation will work, I personally would see a bigger > possibility of an anti-matter drive than for hibernation. I agree that hibernation is risky technically and unsafe. But that doesn't effect its political risk. Politics is about impressions, not realities. > >>The difference between constrution-return and round-trip are not clear since > >>we haven't defined how(=what energy source) the round-trip makes its return. > >>So its not clear how the differences in feasability are explained. > > > >Rount trip could use a fusion powered ship that mines fuel in the system. > >Possibly with a fuel launcher construction option. > > Of course we need to know if the fuel we need can be found and mined easely. > Although hydrogen will be present, it may not be as concentrated as we like. And of course the fusion systems I'm assuming don't burn hydrogen. It is a risk, but we have little else that might work. ============================================================================= > > >Not likely. We have no reason to asume we'ld find any earth like planets > >in neighboring star systems. Especiall ones that are so earth like as to > >be comfortable. (I.E. an Earth like world that was no cooler or wetter > >than the Sahara or warmer than the antarctic in winter, would still be > >remarkable.) Certainly if you sticking to the L.I.T. Tau C. flight idea, > >by definition their were no even vaugly earth like worlds spotted there. > > Then why are we going, one of the main LIT objectives was that > there was a strong evidence of life in the system we would explore. > > When there is life it will almost certainly have some acceptable temperature. Life can survive and thrive in a lot of environments that we could possible survive. Temps of hundreds of degrees F, radiation, low grav and presure, deep oceans etc. I don't remember anything in the LIT charter that suggested an earth like ecosphere. It didn't even have a planet anywhere clse to earth in mass. The charter was just we found a solar system and people wanted someone to go and check it out. It never said they'ld want to colonize it. ============================================================================= > > >>A problem with staging is that you throw away your ship, this makes a > >>two-way mission much harder! > > > >Agreed. > > So, do you know how to solve it without having a big industry at the remote > end of the trip? You could save the light high tech parts of the stages (fuel processors, power systems, etc) and throw away the heavy structure and tanks. That might allow you to rebuild the heavy stuff in the starsystem from local ores, and refit it with the salvaged parts of the old stages. However you should note that staging quickly requiers a HUGE ship. You quickly might need to mine a starsystem for fuel. > >>This is not certain, the ideas I stated some time ago are only a few and > >>were considered as most preferred though less easy methods. There does not > >>have to be a real difference between a fusion or an anti-matter powered > >>ship. Both can be used as heat-energy sources to accelerate reaction mass. > > > >True, but I wasn't expectin to use the fusion power to heat a rockets > >reation mass. That would threaten to melt the ship quickly. > > How where you going to use that heat then? Does it matter that > much if you are first tranforming the heat into electricity? The Bussard reactors, and the fuels they use; don't produce radiation, heat, or the rest. The power comes out as charged fast moving particals. Those particals can be run past a magnetic feild for almost perfect conversion of the fuels power to electricity (with virtually no thermal load) or released as a reaction mass. > >>FTL is a principle that has been withstanding many experiments to unprove > >>it. Chances are small that FTL will become possible in the next century (if > >>at all). > > > >Small but not impossible. It seems ftl is possible, but we know of no way > >to do it with any realistic physical system, much less a buildable one. > >But then we would have said that about space travel a couple of cventuries > >ago. It definatly requires some new physics (as opposed to engineering) > >tricks. Then again, without it star travel beyond the nearest stars will > >never be practical. > > Why does it seem that ftl is possible, I've never seen a serious article > that stated to have found a way to make a signal travel faster than the > speed of light. Even not in tunneling! I've seen several major physivs papers talk about the theoretical consistency with FTL and time travel, worm holes and the like. Also some are interpreting the one hole show partical, two hole shows a wave, experiments as showing ftl feedback. Also by def, quantum shifts of electrons happen instently. ========================================================================== > > >I don't follow that last bit. Presumably a one way flight could construct > >a larger space platform for living quarters. But if they could construct > >anything that extensive, they could build a way to get home. So presumably > >eiather way they are stuck in the ship. Just for a lot longer if they > >aren't coming home. > > Indeed they could, but maybe they would not want to stay any longer in a > small ship. Of course this depends on the duration of the trip. Especially when comparing it with several decades of possibly remaing life expectency. A couple of which would be lost on a colony. Kelly From popserver Fri Feb 9 02:07:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2621" "Thu" "8" "February" "1996" "20:30:43" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "59" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA09007 for ; Thu, 8 Feb 1996 17:33:50 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id UAA13432; Thu, 8 Feb 1996 20:30:43 -0500 Message-ID: <960208203042_139506872@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Thu, 8 Feb 1996 20:30:43 -0500 To Tim >>> Maybe we should make them just smart enough to do > >>> the dirty jobs. And use only a few with IQ 1000 to think. > > > >;) You can't hide forever. Best to come out a deal with things as theyt > >happen, not try to lock yourself into a safe past. > > It's not lock yourself, it's protecting yourself. It's like saying, why not > do any kind of genetic experiment, you can't stop it anyway. We will do genetic experimentation, and A.I. because both are very important/valuble. In both cases we will try to be carefull and will make mistakes. Thats just life. Trying to put some wall that you can only make stupid A.I.s (assuming we had some way to control that) would be clumbsy and impractical. Probably as dangerous as a hostile hi I.Q. A.I.. > Of course smart computers are not necessary dangerous, maybe they > LIKE to help us out. If they are convinced that we are not just > annoying bugs, then the problem may not be that worse. Humans are a very adaptable species. We will probably be worth trading with. If not we have no obvious point of friction, so an intelegent A.I. species that didn't like us, would just leave. (Thou a stupid one might try world conquest.) Are you this paranoid about aliens? How would you deal with a hyper evolved E.T.? If you don't think we'ld be able to deal with domestic aliens of our own creation, how can we deal with ultra-E.T.s? > >>> Yes, I found some info about another CRAY having max 1.2 TFLOPS. > > > >Ok, so we have the electronic brains. Now for the minds! > > As soon as the structure of the brain and its input is ready the mind will > follow automatically. > The input is something that a lot of people forget. I think for any brain to > start working, the input should be sufficiently high. And if we want a > computer that is least likely to kill us and most likely to understand us, > we should make its senses similar to ours. Ready? I suppose we could just CAT scan in someones brain and have it emulate it. > I think there is another possibility to control the AI, we let it "live" in > a virtual reality, which is created by us. So every action the AI undertakes > will not be a real one (so no harm to us), but since we can control it's > input it may never know that it is not real. You forget. It isn't a physical creature, it is a data construct. A 'virtual reality' would be very alien to it. It would probably bypass it to the more natural binary data space. Our physical world of time and space could seem very alien. Other concepts, like death, have caused some confusion for advanced A.I. prototypes. Kelly From popserver Fri Feb 9 02:07:06 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7787" "Thu" "8" "February" "1996" "20:31:00" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "185" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA09083 for ; Thu, 8 Feb 1996 17:34:36 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id UAA04951; Thu, 8 Feb 1996 20:31:00 -0500 Message-ID: <960208203058_139507106@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Thu, 8 Feb 1996 20:31:00 -0500 Subj: Re: Hands and brains to: Timothy van der Linden > To Kelly: > > >> But why do elephants have such big brains (3 to 4 times larger than > >humans)? > > > >They need the nuerons to run their big bodies, which are dozens of times > >humans. > > Are you sure or are you guessing? The story that David wrote, I had heard > before. It was the reason why I thought (before I read otherwise) that an > elephant (and a dolphin) had a small brain too. Yes, elephants have very large brains with normal sized cells, but the cells are not aranged in a complex structure, and are not as proportionally large as humans. Dolphins brains are larger (in mass and proportion) then humans, and are more structuralu complex, but the complexity isn't in the intelegence centers. > Looking at this after discussing it, a possible explanation may be that the > brain-cells are much bigger. This may also be the case for dolphins. So when > saying the absolute size, I should have said the number of neurons. I don't > have any confirming data however. I'm going to search for some more data > about this. > > >> >automate systems will work well and productivly. Which is why all large > >> >manufacturing industries use them. > >> > >> But that means that much less people can do the job > > > >Yes. > > So if you go on a few centuries, only a few people have to work. This is > where I was going to. Look what happened in the past. Technology allowed farming (which used to take up the bulk of the population) to be done by less than 5% of the pop. That doesn't mean the other 95% decided to goof off all the time. They just spend their time doing something else. > >> It's keeping the heat in: Greenhouse gasses are more opaque planetary > >> radiation than for solar radiation. Solar radiation is what directly comes > >> from the Sun and planetary radiation is > > > >I know the theory, I also know their is no data to support it. > > Of course I don't have the hands on an experiment that proved it but I find > it very hard to believe that no one has tried to figure out to what kind of > radiation the so called greenhouse gasses are most opaque. This very simple > experiment would show the proof or rebuttal. It is not a simple experiment. NASA tried to do some studies comparing thermal emmisions from earth and space to get a ballence audit. So far the info is frustratingly inconclusive. Climatologists really have little handel on what percentage of the earths heat comes from solar heat, or converted light, or internal heating. Then again, it was only a few years back that someone showed the greenhouse effect dosen't work in greenhouses. Bottom line, no one has any models that acuratly predict anything about climate on that scale. We just don't know the fundamentals that well, and the extream mass of calculations would swamp any of our current computers. None of the globalwarming theories predictions agree well with one another, or with our real history. (Ask Kevin about the iunseasonably warmer winters that we are supposed to be having. Parts of his area hit -60 F!) And no one has been able to detect a credible (acuratly messurable) temperature increase. Few of the temperatures are even take in areas that would show such an effect. For example if you check city temps you will see and increase. but it maps to urban growth around the airports where the temps are taken. Not to state wide temps. (Thats why NASA tried using global thermal images.) > >It is also argued if the earth is getting warmer or cooler. NASA went back > >over 25-30 years of satelihgt scans. They could have detected a change as > >small as 1/5th the smallest variation predicted by any of the green house > >theories. They didn't find it. Longer term arcio-climatology studies have > >shown a cooling since the mid 1800, a warming from the 1700, and a long term > >cooling over the last 800 years. > > Did these images show there was no temperature increase or did they show > that there was no increase due to the so called greenhouse effect. If you > mean the latter, how can they distinguish between normal and greenhouse > deviations? They showed no detectable global increase in temp. > >> To that I agree, but as long the greenhouse effect is not too large the > >> temperatures will not become so high that no live can exist. At the > >> light-side of the moon you will freeze to death (assuming you weren't > >> choking first) this is because there are no gasses to keep the heat in. The > >> only heat there is radiative heat. > > > >How do you freeze to death at 200 degrees F? Trust me, freezing wasn't a > >problem on the moon in full sunlight. > > Yes, that is radiative heat, not convective. So everything that is in the > shadow is much colder. I assume that if you where standing with your back to > the Sun than your belly would freeze. Worse if your in the shadow of a rock! > >> I think that if chemicals are not recycled any amount is used up in a > >> relative short period. (If water and carbondioxide where not recycled by > >> plants, animal (non photosynthesis) live would very soon die away). > > > >But the chemicals are being recycled by the planetary geo-processes, and they > >have sustained their local populations for a very long time. > > Yes, but the chances for evolution are not very big in a small (local) area > where the climate is relatively stable. Higher evolutionized animals would > not occur due to serious inbreading. But in an alien environ those isolated patchs here, could be the norm for the planet. (It would be worth a lot of study, but no one would want to live there!) > >> I've seen a TV-series (again :) ) that tried to explain that the human > >brain > >> expanded as soon as it began standing up. The reason for that was the > >> temperature difference between 0.8 metre (on 4 legs) and 1.5 metres (on 2 > >> legs) above the ground. ------- > >> One question remains however, why didn't they get a bigger brain while in > >> the forest before the mountain ridge appeared? > > > >Or why didn'tproto apes in cooler climates develop it. > > Ah, I think I know, they had a live that was too easy, so there was no > advantage of being smart. The apes on the rather dry and hot savannas had to > do more for their food than just sitting on a branch. Yeah, something about having to go hunt down your food and not just reach out for it. Its still debated thou. > >Besides, humans are > >warm blooded. They keep thie brain tissue withing a fraction of a degree of > >temp. > > But it is much harder to cool in higher temperatures. We aren't well evolved for higher temps, so we probably didn't live in them. > >Humans have an odd brain hand trick we retained since we were tree dwelers. > > It makes certain types of eye hand coordination easier (real important when > >your jumping for a branch) but humans brains developed long after our bodies > >and hands were developed. > > So you do agree (to a certain degree) that there is a more than normal > connection between hand and brain? Not for other tree dwelling apes or monkeys, but it is an unusual structure. but then humans have had a very odd history. trees, to water, to savanas, and each left odd evolutionary twists ranging from legs, fat distrabution, noses, weak lower backs, etc.. Maybe thats why we finally developed intelegence. We were such an adaptable patchwork, that without intelegence we couldn't use our bodies as well as they were capable of. > >Why did humans develop such powefull minds? Thats a hotly debateed question. > > Yes, I noticed ;) > > Tim Pity those damb chimps didn't keep good records! "yes another long leged freak with a passion for long walks. Its parents were heartbroken..." Kelly From popserver Fri Feb 9 06:07:13 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["301" "Thu" "8" "February" "1996" "22:37:38" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "12" "Re: RE: REPLY ALL" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA18695 for ; Thu, 8 Feb 1996 19:39:38 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id WAA10763; Thu, 8 Feb 1996 22:37:38 -0500 Message-ID: <960208223737_139630438@mail04.mail.aol.com> From: KellySt@aol.com To: bmansur@oc.edu, David@interworld.com, hous0042@maroon.tc.umn.edu, jim@bogie2.bio.purdue.edu, rddesign@wolfenet.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: RE: REPLY ALL Date: Thu, 8 Feb 1996 22:37:38 -0500 to: Brian V. Mansur >> Subject: replying to everyone >> Date: Saturday, Feburary 8, 1996 9:30 AM >> I just discovered the REPLY ALL button on my e-mail >> program! Now I can die happy. You need a life (and a new online calendar ;) ). Be warned, net service to the dead is very bad. ;) Kelly From popserver Fri Feb 9 06:07:15 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["441" "Thu" "8" "February" "1996" "22:37:30" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "18" "Re: Where is everyone" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA18704 for ; Thu, 8 Feb 1996 19:39:45 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id WAA27081; Thu, 8 Feb 1996 22:37:30 -0500 Message-ID: <960208223729_139630341@emout04.mail.aol.com> From: KellySt@aol.com To: rddesign@wolfenet.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@interworld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl Subject: Re: Where is everyone Date: Thu, 8 Feb 1996 22:37:30 -0500 to: rddesign@wolfenet.com >> Just wondering what has happened. I haven't seen any >> messages for a week now and I am begining to think I >> have missed some importent infomation. >> Do we have a newsletter again? Is the LIT web site up >> and folks are posting there? I'm going into LIT >> withdrawl. :-) >> Ric Sorry, I droped off line. Don't panic! Don't get delusional. ;) Kelly From popserver Fri Feb 9 09:42:10 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1152" "Fri" "9" "February" "1996" "10:38:32" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "31" "Re: Anti-matter" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA02047 for ; Fri, 9 Feb 1996 01:40:01 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA01341 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 10:38:26 +0100 Message-Id: <199602090938.AA01341@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Anti-matter Date: Fri, 09 Feb 1996 10:38:32 +0100 Reply to Brian: >Has anyone heard anything on the progress of making anti-hydrogen? I read >in a Discovery Mag article that someone was going to give it a serious go at >it last fall. Yes, at least I did read it somewhere, unfortunately the process to make anti-hydrogen is not as efficient as we would like. They only made 7 atoms. And I'm not sure yet if it would be easier to have matter or ions. There is something though that may give anti-particles a real impact. Some theories say that they may have anti-gravity. It is yet not possible to experimentally verify that, but in a few years an experiment can be done. You said that you had not time yet to collect all names of the MiniLIT members. They are in the header of every letter but depending on your mail-program that may not be visible. So I added them for you here. Do you know already what aliases are, if not, try figuring it out, it makes mailing to many people a lot easier. KellySt@aol.com stevev@efn.org T.L.G.vanderLinden@student.utwente.nl jim@bogie2.bio.purdue.edu zkulpa@zmit1.ippt.gov.pl hous0042@maroon.tc.umn.edu rddesign@wolfenet.com David@InterWorld.com Timothy From popserver Sat Feb 10 01:06:40 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["135" "Fri" "9" "February" "1996" "17:19:23" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "6" "Re: REPLY ALL" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA07489 for ; Fri, 9 Feb 1996 16:27:11 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19010 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:16 +0100 Message-Id: <199602091619.AA19010@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: REPLY ALL Date: Fri, 09 Feb 1996 17:19:23 +0100 To Brian, My message about the "reply-all" seemed to have arrived just too late, because my slip-client did not work. Sorry, Timothy From popserver Sat Feb 10 01:06:45 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["954" "Fri" "9" "February" "1996" "17:19:31" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "22" "Re: I found the food numbers!" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA07510 for ; Fri, 9 Feb 1996 16:27:22 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19017 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:20 +0100 Message-Id: <199602091619.AA19017@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: I found the food numbers! Date: Fri, 09 Feb 1996 17:19:31 +0100 To Kelly >> Any high quantity of radiation of the latter two classes is likely to >> cause degradation of the food over time. > >Unless of course the fusion fuel you specified doesn't produce neutrons. Off >hand I can't think of a Gama source on the ship, unles we use antimater. In >that case we have a very hard radiation problem in general. I did not mean the radiation hazard of the engine, but the cosmic radiation, since we were talking about shielding. As far as I know Steve was only trying to make clear which kind of radiation could or could not affect the food. >We might have more problems with cosmic radiation, especially on fast ships. > But given the tolerance of the food vs the human crew I don't, think, it >will be a problem. Certainly less than with a farm where the food has to be >kept healthy to grow. May well be, but this whole discussion started because you suggested that stored food would not need shielding. Timothy From popserver Sat Feb 10 01:06:47 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1694" "Fri" "9" "February" "1996" "17:19:19" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "29" "A new way of DEcelerating" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA07541 for ; Fri, 9 Feb 1996 16:27:32 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA18992 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:03 +0100 Message-Id: <199602091619.AA18992@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: A new way of DEcelerating Date: Fri, 09 Feb 1996 17:19:19 +0100 I'm currently reading a book "Extraterrestials, where are they". It's not a sf and it dicusses the the possibilities of alien life and its exploration of the universe. It also has a chapter about propulsion systems. They came up with several methods for acceleration (about the same as we did) and only one feasable deceleration method, that of pellets being sent 100 years before the real launch. There was another method not found by us, that method had a rather bad theoretical background so they couldn't say if it would work as well as we would like. I have a hard time understanding it, but it has to do with using electromagnetic (EM) coupling of the interstellar PLASMA. It seems that there are also some ions in the ISM. The EM influence of these ions may be somewhat smaller than the normal pressure of the uncharged ISM. It would require a HUGE array of conducting lines, which could be towed (passively) behind the ship. I think, but am not sure that the EM turbulence induced by the lines and the plasma will reduce the speed of the ship. (This system is called the "Alven Propulsion Engine" and was discovered by Drell, Foley and Rutherman in 1965) They calculated that the mass/surface ratio should be less than 1E-9 kg/m^2 if you want to stop in a feasable time, this is of course not very easy to make. They suggest to use 1-micron-diametre wires. So in all, it is a possibility but there have to be done experiments to make sure it will work well enough. Since our ship is assumed to be much heavier than the one the book was suggesting, we need a HUGE (I don't know how huge) array of conducting lines. This method has an attractive side, that of passive braking. Timothy From popserver Sat Feb 10 01:06:48 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2552" "Fri" "9" "February" "1996" "17:19:43" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "50" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA07589 for ; Fri, 9 Feb 1996 16:27:58 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19036 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:35 +0100 Message-Id: <199602091619.AA19036@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Fri, 09 Feb 1996 17:19:43 +0100 Again to Kelly, >We will do genetic experimentation, and A.I. because both are very >important/valuble. In both cases we will try to be carefull and will make >mistakes. Thats just life. Trying to put some wall that you can only make >stupid A.I.s (assuming we had some way to control that) would be clumbsy and >impractical. Probably as dangerous as a hostile hi I.Q. A.I.. Yes, I was only saying we should be careful, indeed by constantly taking small steps and not by taking big leaps without having a clue what would be possible. This may sound logical but it would make a little difference to use 1E6 or 1E12 neurons when you have enough computing power available. >Humans are a very adaptable species. We will probably be worth trading with. > If not we have no obvious point of friction, so an intelegent A.I. species >that didn't like us, would just leave. (Thou a stupid one might try world >conquest.) What would there be to trade? What would a smart computer need? Indeed it would be smart of them to leave us because we are only a problem for them. But this is only the case if we outnumber them. But what if they got control over vital human needs like electricity or computing power. That would be really weak points for humans. >Are you this paranoid about aliens? How would you deal with a hyper evolved >E.T.? If you don't think we'ld be able to deal with domestic aliens of our >own creation, how can we deal with ultra-E.T.s? I'm never paranoid, I was just sharing a few thoughts and looking what you (or others) thought about it. If these ETs indeed are more evolved and stronger/smarter than we are, then the outcome would more depend on them than on us. (Unless there are just a few) >> I think there is another possibility to control the AI, we let it "live" in >> a virtual reality, which is created by us. So every action the AI >undertakes >> will not be a real one (so no harm to us), but since we can control it's >> input it may never know that it is not real. > >You forget. It isn't a physical creature, it is a data construct. A >'virtual reality' would be very alien to it. It would probably bypass it to >the more natural binary data space. Our physical world of time and space >could seem very alien. Other concepts, like death, have caused some >confusion for advanced A.I. prototypes. I think it would very soon be bored about the binary space. But does it matter how its VR would look? The main idea is that we control its input and we could redirect its output to make it harmless. Timothy From popserver Sat Feb 10 04:02:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4175" "Fri" "9" "February" "1996" "17:19:51" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "84" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA12757 for ; Fri, 9 Feb 1996 17:22:57 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19053 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:40 +0100 Message-Id: <199602091619.AA19053@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Fri, 09 Feb 1996 17:19:51 +0100 More reply to Kelly >> Are you sure or are you guessing? The story that David wrote, I had heard >> before. It was the reason why I thought (before I read otherwise) that an >> elephant (and a dolphin) had a small brain too. > >Yes, elephants have very large brains with normal sized cells, but the cells >are not aranged in a complex structure, and are not as proportionally large >as humans. Dolphins brains are larger (in mass and proportion) then humans, >and are more structuralu complex, but the complexity isn't in the intelegence >centers. So than the final question is what determines the complexity of the connections? >Look what happened in the past. Technology allowed farming (which used to >take up the bulk of the population) to be done by less than 5% of the pop. > That doesn't mean the other 95% decided to goof off all the time. They just >spend their time doing something else. Only food would not be enough for a humane living, clothes, a house, health, communication, travel and amusement are important too. Nowadays a lot of these things are automated and need less people to operate. These days the first needs for life are more and more automated, so no one has to work after a few decennia but of course the secondary needs aren't that far YET. A lot of people would rather not have to work, when they have a certain minimum (depends per individual) they just want to maintain that and do the things they like. Of course some of them just like to work, but there is a significant difference in wanting to work or having to work. >> Of course I don't have the hands on an experiment that proved it but I find >> it very hard to believe that no one has tried to figure out to what kind of >> radiation the so called greenhouse gasses are most opaque. This very simple >> experiment would show the proof or rebuttal. > >It is not a simple experiment. NASA tried to do some studies comparing >thermal emmisions from earth and space to get a ballence audit. So far the >info is frustratingly inconclusive. Climatologists really have little handel >on what percentage of the earths heat comes from solar heat, or converted >light, or internal heating. Ah, but in that experiment they didn't test the isolating properties of greenhouse gasses. They tested the total result. So since greenhouse gasses do keep the heat in (I'm sure that is tested) they should have conlcuded that there probably were some other mechanisms reducing the effect of heating up. (I've seen graphs showing the amount of CO2 rose significantly since 200 ago) For example a higher amount of CO2 increases the growth of plants, so in total they absorb more light and store it in their leaves instead of reflecting it as heat. >Then again, it was only a few years back that >someone showed the greenhouse effect dosen't work in greenhouses. I heard this before but still don't know how they thought a greenhouse worked. Of course the glass walls are much better of keeping the convective heat in than the greenhouse gasses are in keeping the radiative heat in. >> Did these images show there was no temperature increase or did they show >> that there was no increase due to the so called greenhouse effect. If you >> mean the latter, how can they distinguish between normal and greenhouse >> deviations? > >They showed no detectable global increase in temp. So all these stories about a global temperature increases of 0.2-0.4 C/year are not true? >But in an alien environ those isolated patchs here, could be the norm for the >planet. (It would be worth a lot of study, but no one would want to live >there!) Yes, but it would mean they could not have evolved to higher organisms. >Not for other tree dwelling apes or monkeys, but it is an unusual structure. > but then humans have had a very odd history. trees, to water, to savanas, >and each left odd evolutionary twists ranging from legs, fat distrabution, >noses, weak lower backs, etc.. Maybe thats why we finally developed >intelegence. We were such an adaptable patchwork, that without intelegence >we couldn't use our bodies as well as they were capable of. That's an interesting theory... Timothy From popserver Sat Feb 10 04:02:57 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["8931" "Fri" "9" "February" "1996" "17:19:36" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "180" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id RAA12802 for ; Fri, 9 Feb 1996 17:23:16 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19027 (5.67b/IDA-1.5 for ); Fri, 9 Feb 1996 17:19:29 +0100 Message-Id: <199602091619.AA19027@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Fri, 09 Feb 1996 17:19:36 +0100 Also to Kelly >I'm just saying that there is a limit to the amount of information that can >be transmitted inteligably over interstellar distences even is your playing >with all the usable spectrum. Obviously the local star(s) will drown out >most of the frequency bands, given that earth scopes will be looking straight >at it. So we will eiather have to make due with that stars quiet bands, use >incredible amounts of power (you really want to out shout a star?), and use a >lot of low bouad and error correction to make up for interfearence. There indeed will be a limit but is that limit really to small? These SETI-programs seem to scan many bands, and their telescopes are pointed directly at the stars. I assume they have made some calculations about Signal to Noise ratio. I am not saying that it is easy but we were more or less assuming we could use a beam to propell the starship. If we are not able to propell a starship with it we certainly could use it as a transmitter for information. ============================================================================== >> >Thats a possibility. It certianly would be politically less likely to be >> >funded allong its entire history. But given that expenses would be spread >> >out over a longer time it might cost less over a given period of time. >> > >> >I'm surprized you objected to this section thou, since its the only option >> >(i.e. assured routine supply flight) that woulkd allow a colony mission? >> >> I'm just being consequent. > >Consequent? Is that the word you ment? Does that word not exist in English? I meant consistant. ============================================================================== >A simple system like a fuel launcher that only has to work for a couple >months every few deacdes should be able to be automated once its set up. And >making redundant copies will assure acceptable relyability. Also the first >thing eveyone does when entering the system is repair the fuel launcher. In this conclusion you say that it could work automatically for a few months or so. Could we really trust such a big machinery to keep on working for several months (if not a year)? Because when it doesn't, that means we are doomed. Besides that I can recall some one saying that an Earth-based launcher would be better than a ship-based launcher because of the amount of people needed to operate it (and because of the weight that the ship doesn't need to carry, but that isn't discussed here). >I wasn't building a mirror (what i the hell would it be for anyway?), and >colonies need air and water recyclers, housing for humans, furniture, >hospitals, and a lot of other things that a automated platform wouldn't need. What makes an air & water recycler so much more difficult to build than a launcher? Indeed a launcer doesn't need medcine or food but it needs large amounts of well refined fuel. ============================================================================== >> We are not talking about religious groups. --- > >Well obviously only a very 'focused' group of beleavers are going to condem >themselves to perminent imprisionment for a multi-gen cause. I wonder if that is really true, there are many people who have a focused goal, but that doesn't mean that they are no able or not allowed to think for themselves. >> On a multi-gen ship there will also be a scientific crew, they are >> explorers. If then need some practical experience, they will have all the >> time they need. Simulators for shuttles and vehicles could do a great job >> helping them. > >You can't simulate exploring planets in the confines of a vitual reality >simulator, nor can you learn everything about fliying high performance >aircraft without flying them. None of which can be done completly in a sim. > In a multi-gen crew. Nothing anout exploration, not even seeing a real sky >or horizon would be familure to them. Indeed they would not have experience walking through the landscape etc. But they could learn fast enough. A multi-gen ship would not need to examine the star-system within a small period. If they wanted they could take a few generations. They would be excellent objective observers since they wouldn't know very well what Earth was like. Flying aircrafts perfectly isn't necessary, as long as the flight and landing is reasonable smooth that is enough. >> It's a big risk trusting your live to a automated system on which you would >> have no control. A single programming error can shut down the power source >> and there would be no one to turn it on again. > >Compared to the dangers of a colony, thats trivial. At least one has the idea that it can do something about it when living in a space colony. And why should a space colony be so significantly more dangerous than a 5 year flight in space? >I agree that hibernation is risky technically and unsafe. But that doesn't >effect its political risk. Politics is about impressions, not realities. The media would certainly point at all possible difficulties, certainly such obvious ones. ============================================================================= >>When there is life it will almost certainly have some acceptable >>temperature. > >Life can survive and thrive in a lot of environments that we could possible >survive. Temps of hundreds of degrees F, radiation, low grav and presure, >deep oceans etc. I don't remember anything in the LIT charter that suggested >an earth like ecosphere. It didn't even have a planet anywhere clse to earth >in mass. The charter was just we found a solar system and people wanted >someone to go and check it out. It never said they'ld want to colonize it. OK, I forgot that. ============================================================================= >> So, do you know how to solve it without having a big industry at the remote >> end of the trip? > >You could save the light high tech parts of the stages (fuel processors, >power systems, etc) and throw away the heavy structure and tanks. That might >allow you to rebuild the heavy stuff in the starsystem from local ores, and >refit it with the salvaged parts of the old stages. I wonder if any part at a rocket engine can be regarded as not hi-tech. And if it is, it still takes quite a while to rebuild and assemble all the parts. You don't want several parts to break down while you are on your way back. >However you should note that staging quickly requiers a HUGE ship. You >quickly might need to mine a starsystem for fuel. It's the use of fusion-fuel that causes this, staging is a result of using fusion fuel. (Just a minor difference) >> How where you going to use that heat then? Does it matter that >> much if you are first tranforming the heat into electricity? > >The Bussard reactors, and the fuels they use; don't produce radiation, heat, >or the rest. The power comes out as charged fast moving particals. Those >particals can be run past a magnetic feild for almost perfect conversion of >the fuels power to electricity (with virtually no thermal load) or released >as a reaction mass. I really wonder how this works, does the LIT-page about this, cover that part? >I've seen several major physivs papers talk about the theoretical consistency >with FTL and time travel, worm holes and the like. Also some are >interpreting the one hole show partical, two hole shows a wave, experiments >as showing ftl feedback. Also by def, quantum shifts of electrons happen >instently. Not exactly, it always takes time to tunnel but at a certain tunnel-length the "travel time" does not become any longer. This indeed, makes it look as if the electron (wave distribution) has travelled faster than light. But it seems that the front of the wave-packet did not move faster than light. But somehow during tunneling the packet became smaller and thus the center of the packet was shifted forward a little. The center of the wave gives the biggest probability of detecting the particle. I can't explain any more right now, since the scientists aren't sure either. In wormholes or other places where space is bended, the local speed of light is still the same. However the global speed may indeed change. The same thing happens when you are moving (at near light speed). If we could bend (warp) space than indeed global ftl would be possible. But then you would need to prepare a passage before you could fly through it. A ship that would bend its own space would not be able to globally fly ftl because it still needed to move that bended area at a speed slower than light. It's global time would slow down though, so they would think they had crossed the area in a shorter time, but when they would return to their homebase they would notice the same effect as if they had been flying at near light speed. Of course all this assumes that space can be bended enough be artificial and usefull ways. Timothy From popserver Sat Feb 10 04:03:06 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5747" "Fri" "9" "February" "1996" "08:46:54" "-0500" "David Levine" "David@interworld.com" nil "214" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA13713 for ; Fri, 9 Feb 1996 17:31:34 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA591; Fri, 9 Feb 1996 08:50:50 -0500 Message-ID: <311B504E.18C9@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0 (WinNT; I) MIME-Version: 1.0 References: <960208203042_139506872@mail04.mail.aol.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: KellySt@aol.com CC: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Fri, 09 Feb 1996 08:46:54 -0500 KellySt@aol.com wrote: > Humans are a very adaptable species. We will probably be worth trading with. > If not we have no obvious point of friction, so an intelegent A.I. species > that didn't like us, would just leave. (Thou a stupid one might try world > conquest.) > > Are you this paranoid about aliens? How would you deal with a hyper evolved > E.T.? If you don't think we'ld be able to deal with domestic aliens of our > own creation, how can we deal with ultra-E.T.s? > This was forwarded to me recently. You guys may have seen it before. If so, sorry. It's the first time I saw it. This bit of the MiniLIT discussion reminded me of it: -David ________________________________________________________________ _______________ From: Stecyk-Ramos, Polly on Tue, Jan 23, 1996 9:06 AM Subject: FW: Meat To: am@es; Anne Gillies; Berman, Andrea; DLynn.El_Segundo@xerox.com; Fitts, David; Hwang, Erica; LEN9310@ACS.TAMU.EDU; Mom; Parsons, Carmen; STECYK AMY NATALIA Rather imaginative - enjoy! ________________________________________________________________ _______________ light humor: Imagine if you will... the leader of the fifth invader force speaking to the commander in chief... "They're made out of meat." "Meat?" "Meat. They're made out of meat." "Meat?" "There's no doubt about it. We picked several from different parts of the planet, took them aboard our recon vessels, probed them all the way through. They're completely meat." "That's impossible. What about the radio signals? The messages to the stars." "They use the radio waves to talk, but the signals don't come from them. The signals come from machines." "So who made the machines? That's who we want to contact." "They made the machines. That's what I'm trying to tell you. Meat made the machines." "That's ridiculous. How can meat make a machine? You're asking me to believe in sentient meat." "I'm not asking you, I'm telling you. These creatures are the only sentient race in the sector and they're made out of meat." "Maybe they're like the Orfolei. You know, a carbon-based intelligence that goes through a meat stage." "Nope. They're born meat and they die meat. We studied them for several of their life spans, which didn't take too long. Do you have any idea the life span of meat?" "Spare me. Okay, maybe they're only part meat. You know, like the Weddilei. A meat head with an electron plasma brain inside." "Nope. We thought of that, since they do have meat heads like the Weddilei. But I told you, we probed them. They're meat all the way through." "No brain?" "Oh, there is a brain all right. It's just that the brain is made out of meat!" "So... what does the thinking?" "You're not understanding, are you? The brain does the thinking. The meat." "Thinking meat! You're asking me to believe in thinking meat!" "Yes, thinking meat! Conscious meat! Loving meat. Dreaming meat. The meat is the whole deal! Are you getting the picture?" "Omigod. You're serious then. They're made out of meat." "Finally, Yes. They are indeed made out meat. And they've been trying to get in touch with us for almost a hundred of their years." "So what does the meat have in mind?" "First it wants to talk to us. Then I imagine it wants to explore the universe, contact other sentients, swap ideas and information. The usual." "We're supposed to talk to meat?" "That's the idea. That's the message they're sending out by radio. 'Hello. Anyone out there? Anyone home?' That sort of thing." "They actually do talk, then. They use words, ideas, concepts?" "Oh, yes. Except they do it with meat." "I thought you just told me they used radio." "They do, but what do you think is on the radio? Meat sounds. You know how when you slap or flap meat it makes a noise? They talk by flapping their meat at each other. They can even sing by squirting air through their meat." "Omigod. Singing meat. This is altogether too much. So what do you advise?" "Officially or unofficially?" "Both." "Officially, we are required to contact, welcome, and log in any and all sentient races or multibeings in the quadrant, without prejudice, fear, or favor. Unofficially, I advise that we erase the records and forget the whole thing." "I was hoping you would say that." "It seems harsh, but there is a limit. Do we really want to make contact with meat?" "I agree one hundred percent. What's there to say?" `Hello, meat. How's it going?' But will this work? How many planets are we dealing with here?" "Just one. They can travel to other planets in special meat containers, but they can't live on them. And being meat, they only travel through C space. Which limits them to the speed of light and makes the possibility of their ever making contact pretty slim. Infinitesimal, in fact." "So we just pretend there's no one home in the universe." "That's it." "Cruel. But you said it yourself, who wants to meet meat? And the ones who have been aboard our vessels, the ones you have probed? You're sure they won't remember?" "They'll be considered crackpots if they do. We went into their heads and smoothed out their meat so that we're just a dream to them." "A dream to meat! How strangely appropriate, that we should be meat's dream." "And we can mark this sector unoccupied." "Good. Agreed, officially and unofficially. Case closed. Any others? Anyone interesting on that side of the galaxy?" "Yes, a rather shy but sweet hydrogen core cluster intelligence in a class nine star in G445 zone. Was in contact two galactic rotation ago, wants to be friendly again." "They always come around." "And why not? Imagine how unbearably, how unutterably cold the universe would be if one were all alone." From popserver Sat Feb 10 04:03:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6694" "Fri" "9" "February" "1996" "09:46:32" "-0500" "David Levine" "David@interworld.com" nil "177" "Power" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA13723 for ; Fri, 9 Feb 1996 17:31:37 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA624; Fri, 9 Feb 1996 09:50:28 -0500 Message-ID: <311B5E48.2278@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0 (WinNT; I) MIME-Version: 1.0 References: <199602090938.AA01341@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Power Date: Fri, 09 Feb 1996 09:46:32 -0500 Hey, gang. This is from the Jan 29, 1996 issue of The Wall Street Journal. (Section A; Page 7A, Column 2). It's also been on ABC news. There seems to be a lot of controvery over this, and no one's quite sure what to make of it yet. A lot of people say it's the old cold fusion thing again, and that 1000+ watt readings must be in error, because the water in the device isn't getting really hot. Who knows. Anyway, it's interesting nonetheless. -David ======================================================== BY JERRY E. BISHOP Staff Reporter of The Wall Street Journal To anyone who remembers the 1989 uproar over cold fusion, it's deja vu all over again. A bottle no bigger than a man's fist is creating an unusual stir among power generation engineers. The bottle is filled with ordinary water and microscopic palladium coated beads. When a little electric current trickles through the bottle, several hundred times as much power starts coming out in the form of heat - that is, if one cares to believe the instruments attached to the bottle. 'No One Knows Why' The instrument readings are enough however, to draw the interest of engineers at a handful of major companies and to prompt at least two university laboratories to attempt to figure out what's going on inside the bottle. "It appears on the surface that it works, but no one knows why," says Quinton Bowles, professor of mechanical engineering at the University of Missouri in Kansas City. The little bottle is known as a Patterson Power Cell, named for its inventor, James A. Patterson, a 74 year old chemist who lives in Sarasota, Fla. Dr. Patterson has turned his power cell over to a startup Clean Energy Technologies Inc. in Dallas headed by his grandson, James W. Reding 26. Mr. Reding is reticent, except to say that CETI is negotiating to license rights to two utilities that he declines to name and to Motorola Inc. A Motorola spokeswoman says, "We wouldn't confirm such a report even if it were true." And so it goes in the tumultuous realm of cold fusion. In 1989 two University of Utah electrochemists Martin Fleischmann and Stanley Pons, triggered the whole cold fusion uproar by saying they had managed to produce nuclear fusion at ordinary room temperatures, using water as a fuel. The notion of a cheap and inexhaustible new source of energy sparked an avalanche of headlines and accolades only to fall into disrepute when others found the work to be irreproducible. Shunned by their colleagues in Utah, Messrs. Fleischmann and Pons retreated to a new cold fusion lab in southern France. 'I Don't Buy It' The Patterson Power Cell differs in some key ways from the Utah approach, but in some quarters, it raises the same level of skepticism. "It's been a long time since anybody tried to sell me the Brooklyn Bridge," says materials scientist Howard K. Birnbaum, who saw the cell demonstrated last October. "I didn't buy it then, and I don't buy it now." Dr. Birnbaum, director of the Materials Research Laboratory at the University of Illinois's Urbana campus, adds that "as far as I can see, there's nothing new going on that would justify [claims] that more energy is coming out than is going in." Yet supporters say something is going on inside the little heat producing bottle. As with the Utah apparatus, it's claimed that the bottle produces an excess of power as it electrolyzes, or breaks down, water molecules into hydrogen and oxygen atoms. But unlike the controversial and unpredictable Utah experiments, The Patterson cell can be turned on and off seemingly at will. Several working devices built by Dr. Patterson have been made available to two teams. "This is the first time what we have a system that seems to work every time," says a nuclear chemist who consults to utilities. The cell's reliability, which would allow scientists to manipulate it, "gives us our first chance to see if this [phenomenon] involves a nuclear reaction," he explains. Moreover, the U.S. Patent and Trademark Office, which has flatly said that cold fusion, like perpetual motion, is impossible and unpatentable, has issued a patent on the gadget. Although both the original Utah devices and the Patterson cell involve the electrolysis of water, there are marked differences. The electrodes in the original devices were small rods of palladium surrounded by coils of platinum wire, and these were hung in a bath of "heavy" water in which the hydrogen is a heavy form called deuterium. The Patterson cell, instead of using palladium rods, is filled with microscopic plastic beads coated with a thin layer of palladium sandwiched between two layers of nickel. And most significantly, it's filled with ordinary water made of "light" hydrogen atoms. In both cases, the hydrogen atoms released by the electrolysis are soaked up by the palladium and/or nickel. It's inside the metal that some kind of energy releasing phenomenon is claimed to take place. A year ago, shortly after CETI was formed, Mr. Reding was touting the Patterson cell as a "coldfusion" system. He has since dropped that claim and now says that "we believe it is something entirely different." He declines to elaborate. A cold-fusion claim implies that the hydrogen atoms are being forced to fuse, a nuclear reaction that usually occurs at 50 million degrees. Physicists say that if the claims were true, the cold-fusion researchers would die from the intense nuclear radiation that would result. The Patterson cell might have been dismissed as easily as other reputed "cold-fusion" apparatus. But Mr. Reding and his colleagues have been bold enough to demonstrate it at three technical conferences in the last nine months. Most cold-fusionists are reluctant to show off their devices, because they are never sure whether or when they will work. Last month, CETI's Mr. Reding showed off a new Patterson cell at an annual gathering of generating equipment manufacturers in Anaheim, Calif. It stood about four inches high and one inch in diameter and held about three tablespoons of the tiny beads. People who watched demonstrations that lasted from 30 minutes to two hours say the instruments indicated that, after subtracting the electricity needed to run pumps and fans, about 0.1 to 1.5 watts of power went into the cell itself, while the heat output was 450 to 1,300 watts. The dubious Dr. Birnbaum at the University of Illinois says that though the cold-fusion claims are "atrocious" Science, the Patterson-cell people "may have stumbled on something else. If so, I hope they are successful and make a lot of money. If not, this ought to be exposed as flimflam." From popserver Sat Feb 10 04:03:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1431" "Fri" "9" "February" "1996" "11:32:12" "-0500" "David Levine" "David@interworld.com" nil "32" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (interworld.com [165.254.130.4]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id RAA13733 for ; Fri, 9 Feb 1996 17:31:40 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA620; Fri, 9 Feb 1996 11:36:11 -0500 Message-ID: <311B770C.1855@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0 (WinNT; I) MIME-Version: 1.0 References: <199602091619.AA19036@student.utwente.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Timothy van der Linden CC: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Fri, 09 Feb 1996 11:32:12 -0500 Timothy van der Linden wrote: > >> I think there is another possibility to control the AI, we let it "live" in > >> a virtual reality, which is created by us. So every action the AI > >undertakes > >> will not be a real one (so no harm to us), but since we can control it's > >> input it may never know that it is not real. > > > >You forget. It isn't a physical creature, it is a data construct. A > >'virtual reality' would be very alien to it. It would probably bypass it to > >the more natural binary data space. Our physical world of time and space > >could seem very alien. Other concepts, like death, have caused some > >confusion for advanced A.I. prototypes. > > I think it would very soon be bored about the binary space. But does it > matter how its VR would look? The main idea is that we control its input and > we could redirect its output to make it harmless. > > Timothy So the "VR" for the AI is not the same as "VR" for us. It's "Virtual Binary" or whatever. Interesting. But I see a problem. For example, we create an advanced AI to control the ship for decisions that need to be made too quickly for us to do. In order to provide a "buffer zone", the AI manipulates virtual controls for the ship instead of real ones. If we approve of the manipulation, we do it to the ship. The problem is that this requires a human "in-the-loop", and we wind up defeating the purpose that we even have an AI for. From popserver Sun Feb 11 00:20:02 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1594" "Sun" "11" "February" "1996" "01:16:23" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "35" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA04823 for ; Sat, 10 Feb 1996 16:17:41 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA21720 (5.67b/IDA-1.5 for ); Sun, 11 Feb 1996 01:16:17 +0100 Message-Id: <199602110016.AA21720@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Recycling/AI and super human computers Date: Sun, 11 Feb 1996 01:16:23 +0100 To David >So the "VR" for the AI is not the same as "VR" for us. >It's "Virtual Binary" or whatever. Interesting. It could be the same, but it doesn't have to be. Although the nature of the brain may be digital its organisation is almost analog or continuous. So I think that depending on it's input sources any environment would be familiar, it only depends on what it gets to see first. Of course after a while when it has seen several environments, it can choose what it likes best, it may indeed be the binary space because of its speed but it may just as well be the natural space because of its even greater complexity. >But I see a problem. > >For example, we create an advanced AI to control the >ship for decisions that need to be made too quickly >for us to do. In order to provide a "buffer zone", >the AI manipulates virtual controls for the ship instead >of real ones. If we approve of the manipulation, we >do it to the ship. The problem is that this requires >a human "in-the-loop", and we wind up defeating the >purpose that we even have an AI for. Indeed, if one use VR to be on the save side, there is always some one needed to control the output. Of course we may assume that if after a certain trial period no threatening outputs where discovered, it could be relatively save to allow certain decisions to be executed directly. A bigger problem may be that the AI does not like to be captured in cyber space and decides to kill itself in some way. Or if its really smart, it could pretend be nice, but as soon as we released it a bit it could take revenge. Timothy From popserver Sun Feb 11 00:20:04 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["729" "Sun" "11" "February" "1996" "01:16:16" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "16" "Cold fusion" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA04818 for ; Sat, 10 Feb 1996 16:17:37 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA21716 (5.67b/IDA-1.5 for ); Sun, 11 Feb 1996 01:16:05 +0100 Message-Id: <199602110016.AA21716@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Cold fusion Date: Sun, 11 Feb 1996 01:16:16 +0100 To David, Now I finally know why extraterrestials haven't come to contact us, thanks. I guess the word meathead is an extraterresitial word... About Cold fusion, I've heard some more stories that cold fusion is not complete nonsense after all. What it is no one seems to know exactly. Of course quantum mechanics has the potential to give us a lot of unknown properties, so it may be the source of some spectacular things. Of course any one using the words cold fusion is laughed at, the media took care of that. But as far as I know there are still people looking at it, but of course they do it rather silently. There is also some info about it on the Web, I haven't read it though, but have wandered along it once. Timothy From popserver Sun Feb 11 21:04:32 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3722" "Sun" "11" "February" "1996" "15:56:48" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "93" "Re: Hands and brains" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA25038 for ; Sun, 11 Feb 1996 12:59:28 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id PAA18567; Sun, 11 Feb 1996 15:56:48 -0500 Message-ID: <960211155646_219513469@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains Date: Sun, 11 Feb 1996 15:56:48 -0500 To: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) > > More reply to Kelly > > >> Are you sure or are you guessing? The story that David wrote, I had heard > >> before. It was the reason why I thought (before I read otherwise) that an > >> elephant (and a dolphin) had a small brain too. > > > >Yes, elephants have very large brains with normal sized cells, but the cells > >are not aranged in a complex structure, and are not as proportionally large > >as humans. Dolphins brains are larger (in mass and proportion) then humans, > >and are more structuralu complex, but the complexity isn't in the intelegence > >centers. > > So than the final question is what determines the complexity of the connections? Yes and why it develops. > >> Of course I don't have the hands on an experiment that proved it but I find > >> it very hard to believe that no one has tried to figure out to what kind of > >> radiation the so called greenhouse gasses are most opaque. This very simple > >> experiment would show the proof or rebuttal. > > > >It is not a simple experiment. NASA tried to do some studies comparing > >thermal emmisions from earth and space to get a ballence audit. So far the > >info is frustratingly inconclusive. Climatologists really have little handel > >on what percentage of the earths heat comes from solar heat, or converted > >light, or internal heating. > > Ah, but in that experiment they didn't test the isolating properties of > greenhouse gasses. They tested the total result. So since greenhouse gasses > do keep the heat in (I'm sure that is tested) they should have conlcuded > that there probably were some other mechanisms reducing the effect of > heating up. (I've seen graphs showing the amount of CO2 rose significantly > since 200 ago) > For example a higher amount of CO2 increases the growth of plants, so in > total they absorb more light and store it in their leaves instead of > reflecting it as heat. To my knowledge no one has tested if "greenhouse gasses" do cause a warming of an isolated system. Even if they did, it would be irrelavant to the global climtae issue. > > >Then again, it was only a few years back that > >someone showed the greenhouse effect dosen't work in greenhouses. > > I heard this before but still don't know how they thought a greenhouse worked. > Of course the glass walls are much better of keeping the convective heat in > than the greenhouse gasses are in keeping the radiative heat in. Glass, like greenhouse gases is opage to heat but not visible light. So it was assumed the light heateed the siol, and the heat couldn't radiate out. > >> Did these images show there was no temperature increase or did they show > >> that there was no increase due to the so called greenhouse effect. If you > >> mean the latter, how can they distinguish between normal and greenhouse > >> deviations? > > > >They showed no detectable global increase in temp. > > So all these stories about a global temperature increases of 0.2-0.4 C/year > are not true? Never heard those claims. The worst temp rise claims I hear expected a 1-3 C change in the next half century to century. Never heard anyone claim a .2-.4 C per year change. NASA's equipment could detect a .2 degree change over the last 25-30 years, but didn't see any change. > >But in an alien environ those isolated patchs here, could be the norm for the > >planet. (It would be worth a lot of study, but no one would want to live > >there!) > > Yes, but it would mean they could not have evolved to higher organisms. Not nessisarily. A complex sizable ecology could evolve complex life forms. Just becuse its based on something very weird doesn't change that. Kelly From popserver Sun Feb 11 21:04:34 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["87" "Sun" "11" "February" "1996" "15:56:23" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "3" "Re: A new way of DEcelerating" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout09.mail.aol.com (emout09.mx.aol.com [198.81.11.24]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA25044 for ; Sun, 11 Feb 1996 12:59:38 -0800 (PST) Received: by emout09.mail.aol.com (8.6.12/8.6.12) id PAA15657; Sun, 11 Feb 1996 15:56:23 -0500 Message-ID: <960211155622_219513214@emout09.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: A new way of DEcelerating Date: Sun, 11 Feb 1996 15:56:23 -0500 Tim, Are their any numbers on how much power per thrust the magnetic break would take? From popserver Sun Feb 11 21:04:35 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7364" "Sun" "11" "February" "1996" "15:56:36" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "176" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA25071 for ; Sun, 11 Feb 1996 13:00:14 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id PAA11897; Sun, 11 Feb 1996 15:56:36 -0500 Message-ID: <960211155636_219513358@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Sun, 11 Feb 1996 15:56:36 -0500 Also to Kelly > > >I'm just saying that there is a limit to the amount of information that can > >be transmitted inteligably over interstellar distences even is your playing > >with all the usable spectrum. Obviously the local star(s) will drown out > >most of the frequency bands, given that earth scopes will be looking straight > >at it. So we will eiather have to make due with that stars quiet bands, use > >incredible amounts of power (you really want to out shout a star?), and use a > >lot of low bouad and error correction to make up for interfearence. > > There indeed will be a limit but is that limit really to small? These > SETI-programs seem to scan many bands, and their telescopes are pointed > directly at the stars. I assume they have made some calculations about > Signal to Noise ratio. I am not saying that it is easy but we were more or > less assuming we could use a beam to propell the starship. If we are not > able to propell a starship with it we certainly could use it as a > transmitter for information. I wasn't assuming we would be using a propulsion beam, much less build one in the target systems. You've pretty wel convinced me that, that isn't practical. SETI wasn't expecting to download the output of a couple hundred researchers and all there raw data. I know bandwidth is a problem on the hubble and the other remote platforms (they use data filtering to skim out the desired parts, and everyone prays they selected the right parts) so I assume the problem would also exist for a starship. ============================================================================== > > >A simple system like a fuel launcher that only has to work for a couple > >months every few deacdes should be able to be automated once its set up. And > >making redundant copies will assure acceptable relyability. Also the first > >thing eveyone does when entering the system is repair the fuel launcher. > > In this conclusion you say that it could work automatically for a few months > or so. Could we really trust such a big machinery to keep on working for > several months (if not a year)? Because when it doesn't, that means we are > doomed. Besides that I can recall some one saying that an Earth-based > launcher would be better than a ship-based launcher because of the amount of > people needed to operate it (and because of the weight that the ship doesn't > need to carry, but that isn't discussed here). Sure, we have a lot of big mechanical systems experience and the launcher is very simple and has very few moving parts. The complex part would be the minning and construction parts, and the crews will be around to supervise that. ============================================================================== > >> On a multi-gen ship there will also be a scientific crew, they are > >> explorers. If then need some practical experience, they will have all the > >> time they need. Simulators for shuttles and vehicles could do a great job > >> helping them. > > > >You can't simulate exploring planets in the confines of a vitual reality > >simulator, nor can you learn everything about fliying high performance > >aircraft without flying them. None of which can be done completly in a sim. > > In a multi-gen crew. Nothing about exploration, not even seeing a real sky > >or horizon would be familure to them. > > Indeed they would not have experience walking through the landscape etc. But > they could learn fast enough. A multi-gen ship would not need to examine the > star-system within a small period. If they wanted they could take a few > generations. They would be excellent objective observers since they wouldn't > know very well what Earth was like. Flying aircrafts perfectly isn't > necessary, as long as the flight and landing is reasonable smooth that is > enough. Thats like giving a navy TomCat fighter and mission to someone whos never been out of doors, much less in and aircraft, but has played the sim game a lot. (The landings should be especiaslly --- colorfull.) > >> It's a big risk trusting your live to a automated system on which you would > >> have no control. A single programming error can shut down the power source > >> and there would be no one to turn it on again. > > > >Compared to the dangers of a colony, thats trivial. > > At least one has the idea that it can do something about it when living in a > space colony. And why should a space colony be so significantly more > dangerous than a 5 year flight in space? Because a space colony is a 50-100 year flight through space. Same life support needs and risks, just for 10-20 times longer, and with and increasingly old and wornout crew and ship. > >I agree that hibernation is risky technically and unsafe. But that doesn't > >effect its political risk. Politics is about impressions, not realities. > > The media would certainly point at all possible difficulties, certainly such > obvious ones. Not if they liked the program. Media generally don't ask many hard questions of things they agree with. Look at how little media investigation there has been on global warming and greenhouse theories. They are every bit as easy to investigate, yet that seldom is done. Certainly my experience at NASA confirms that. > ============================================================================= > >> So, do you know how to solve it without having a big industry at the remote > >> end of the trip? > > > >You could save the light high tech parts of the stages (fuel processors, > >power systems, etc) and throw away the heavy structure and tanks. That might > >allow you to rebuild the heavy stuff in the starsystem from local ores, and > >refit it with the salvaged parts of the old stages. > > I wonder if any part at a rocket engine can be regarded as not hi-tech. And > if it is, it still takes quite a while to rebuild and assemble all the > parts. You don't want several parts to break down while you are on your way > back. I was thinking the pumps and fuel processors, and high energy power systejms wouldn't weigh as much as the propulsion dishes, tanks, and reinforcing structure. Those heavy parts would be easier to rebuild in systems from local ores. You can design systems to function for a while with failures. With a staged system you'ld just need to transfer fuel to the remaining working boosters. > >However you should note that staging quickly requiers a HUGE ship. You > >quickly might need to mine a starsystem for fuel. > > It's the use of fusion-fuel that causes this, staging is a result of using > fusion fuel. (Just a minor difference) Or any fuel without a much higher power to weight ratio. > >> How where you going to use that heat then? Does it matter that > >> much if you are first tranforming the heat into electricity? > > > >The Bussard reactors, and the fuels they use; don't produce radiation, heat, > >or the rest. The power comes out as charged fast moving particals. Those > >particals can be run past a magnetic feild for almost perfect conversion of > >the fuels power to electricity (with virtually no thermal load) or released > >as a reaction mass. > > I really wonder how this works, does the LIT-page about this, cover that part? Don't remember. I'm sure I've discused it a few times and went into some details on my old web page. Kelly From popserver Mon Feb 12 19:06:18 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3265" "Mon" "12" "February" "1996" "18:54:31" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "76" "Re: Hands and brains." "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA01362 for ; Mon, 12 Feb 1996 09:56:00 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24700 (5.67b/IDA-1.5 for ); Mon, 12 Feb 1996 18:54:23 +0100 Message-Id: <199602121754.AA24700@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Hands and brains. Date: Mon, 12 Feb 1996 18:54:31 +0100 To Kelly, >>So than the final question is what determines the complexity of the >>connections? > >Yes and why it develops. I think the latter is clear, being able to use your braincells more efficient is a clear evolutional advantage. Or did you mean something different? >> Ah, but in that experiment they didn't test the isolating properties of >> greenhouse gasses. They tested the total result. So since greenhouse gasses >> do keep the heat in (I'm sure that is tested) they should have conlcuded >> that there probably were some other mechanisms reducing the effect of >> heating up. (I've seen graphs showing the amount of CO2 rose significantly >> since 200 ago) >> For example a higher amount of CO2 increases the growth of plants, so in >> total they absorb more light and store it in their leaves instead of >> reflecting it as heat. > >To my knowledge no one has tested if "greenhouse gasses" do cause a warming >of an isolated system. I think that experiments have been done many years ago. I've read in several books what I wrote before: Greenhouse gasses are more opaque planetary radiation than for solar radiation. This implies that the volume in which the greenhouse gas is present becomes warmer than if it was a normal gas. >Even if they did, it would be irrelavant to the global climtae issue. I can't follow that, or are you saying that Earth's atmosphere isn't an isolated system in this context. >>>Then again, it was only a few years back that >>>someone showed the greenhouse effect dosen't work in greenhouses. >> >>I heard this before but still don't know how they thought a greenhouse >>worked. >>Of course the glass walls are much better of keeping the convective heat in >>than the greenhouse gasses are in keeping the radiative heat in. > >Glass, like greenhouse gases is opage to heat but not visible light. So it >was assumed the light heateed the siol, and the heat couldn't radiate out. But why isn't that true then? Or is it because the heat can radiate out but only not as fast? >Never heard those claims. The worst temp rise claims I hear expected a 1-3 C >change in the next half century to century. Never heard anyone claim a .2-.4 >C per year change. NASA's equipment could detect a .2 degree change over the >last 25-30 years, but didn't see any change. It may well be that my numbers are wrong and should indeed be more like 4 degrees per century but anyhow, they are an increase. And I heard several times that the global temperature was increasing (although not necessary caused by the greenhouse effect). Now I only wonder why NASA's measurement shows something different than other measurements of which I don't recall the source. >>>But in an alien environ those isolated patchs here, could be the norm for >>>the planet. (It would be worth a lot of study, but no one would want to live >>>there!) >> >> Yes, but it would mean they could not have evolved to higher organisms. > >Not nessisarily. A complex sizable ecology could evolve complex life forms. > Just becuse its based on something very weird doesn't change that. I meant that higher organisms could not evolutionize in small areas because there would be not enough food for a population large enough to overcome inbreading. Timothy From popserver Mon Feb 12 19:06:20 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2096" "Mon" "12" "February" "1996" "18:54:39" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "59" "Re: A new way of DEcelerating" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA01358 for ; Mon, 12 Feb 1996 09:55:58 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24714 (5.67b/IDA-1.5 for ); Mon, 12 Feb 1996 18:54:32 +0100 Message-Id: <199602121754.AA24714@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: A new way of DEcelerating Date: Mon, 12 Feb 1996 18:54:39 +0100 >Are their any numbers on how much power per thrust the magnetic break would >take? I'm not certain if you understood the mechanism. It seems that I didn't either: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Now looking at the formulas again, I notice that the plasma needs to move traverse to the flightpath and my assumption of towing the wires behind the ship is probably not right either. They need to be in a network in front of the ship (the plane of the net is perpendicular to the direction of movement.) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! The interstallar plasma is moving, don't ask me why or whereto but the book says it does. What we do is use the magnetic field component that is traverse to the velocity of the ship. /\ || ---------------- moving conducting wire X O X O X O X O magnetic field lines going up or down or aside If the field lines are perpendicular to the direction the wires are moving, then an electric current will start to flow in these wires. The electric resistance turns this current into heat and radiates it away in all directions. All that heat comes from the kinetic energy of the starship and thus the ship slows down. They use the following formula: Drag force= rho V Va A rho=mass density of the plasma V=ships velocity Va="Alfven" velocity=Sqrt[B^2/(4 Pi rho)]=10 km/sec B=traverse magnetic field A=frontal area of the net They use also another way of writing: Drag force = Sqrt(Dh Dm) Dh=hydronamic drag= rho V^2 A (Dh=normal drag due to mass-collisions) Dm=magnetic drag = A B^2/(4 Pi) This system looks a lot like the solid plate in front of the ship catching the ISM to decelerate. The book tries to explain that this magnetic sister may be more usefull due to the size:mass ratio. While one can use thin wires to make use of the magnetic field, one needs a rather thick plane to stop fast moving particles. By the way, Steve, would it be possible for you to explain how a normal magnetic scoop could be constructed. Timothy From popserver Mon Feb 12 19:06:23 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5214" "Mon" "12" "February" "1996" "18:54:48" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "110" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id JAA01400 for ; Mon, 12 Feb 1996 09:56:24 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24721 (5.67b/IDA-1.5 for ); Mon, 12 Feb 1996 18:54:38 +0100 Message-Id: <199602121754.AA24721@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Mon, 12 Feb 1996 18:54:48 +0100 To Kelly, >I wasn't assuming we would be using a propulsion beam, much less build one in >the target systems. You've pretty wel convinced me that, that isn't >practical. Oh yes, it was Kevin who wants to use it. But you do use it in the next part, or is that only for a relative short acceleration period? >SETI wasn't expecting to download the output of a couple hundred researchers >and all there raw data. I know bandwidth is a problem on the hubble and the >other remote platforms (they use data filtering to skim out the desired >parts, and everyone prays they selected the right parts) so I assume the >problem would also exist for a starship. OK, could a satellite in a far orbit around TC be a possibility to overcome the interferring radiation of TC? If we can distinguish big planets from their Sun many lightyears away, I think we can also distinguish some signals of a strong satellite in an orbit beyond the TC-analog of Pluto. ============================================================================== >> Could we really trust such a big machinery to keep on working for >> several months (if not a year)? > >Sure, we have a lot of big mechanical systems experience and the launcher is >very simple and has very few moving parts. The complex part would be the >minning and construction parts, and the crews will be around to supervise >that. It may have few moving parts, but so does a rocket engine. How many rocket engines will be able to work continously for half a year? I imagine such a launcher as an electromagnetic pipeline say 100 km in length and 10 cm in diameter. This is about 10 times as long as the accelerator at CERN. It's diameter is probably many times more. I think we won't reach much more than .5c because at CERN it takes several 1000 turns to get the particles to move that fast. I'm not sure if we need a vacuum assuming we use something like our moon to build the launcher on. But if we do, it means a lot of moving objects (I'm not sure though how high-vacuum pumps do work). On the other hand there is a lot of electronics involved to control al the machinery. Can we be sure that there won't be a fuse that burns through? (I assume there won't be any fuses, since they aren't allowed to burn through anyway) To make an anology, could a nuclear reactor work without anyone present, for half a year? (Limited remote control could be allowed) Besides all this, building such an accelerator is pretty high tech. And you are constantly saying that that isn't possible. ============================================================================== >> star-system within a small period. If they wanted they could take a few >> generations. They would be excellent objective observers since they >> wouldn't >> know very well what Earth was like. Flying aircrafts perfectly isn't >> necessary, as long as the flight and landing is reasonable smooth that is >> enough. > >Thats like giving a navy TomCat fighter and mission to someone whos never >been out of doors, much less in and aircraft, but has played the sim game a >lot. (The landings should be especiaslly --- colorfull.) What I've seen from these simulations, is that they can be quite realistic. g-forces, ever more perfect visual environments. A few weaks ago I saw that there where special simulations for landings on a flightdeck (talk about difficult landings). Maybe the simulations aren't 100% real but I think that 90% is close enough. >> space colony. And why should a space colony be so significantly more >> dangerous than a 5 year flight in space? > >Because a space colony is a 50-100 year flight through space. Same life >support needs and risks, just for 10-20 times longer, and with and >increasingly old and wornout crew and ship. Yes, but you would be able to repair or rebuild things. >Not if they liked the program. Media generally don't ask many hard questions >of things they agree with. Look at how little media investigation there has >been on global warming and greenhouse theories. They are every bit as easy >to investigate, yet that seldom is done. Certainly my experience at NASA >confirms that. Media also like to tackle plans that seem to look OK. Besides why wouldn't they like the idea to build a colony there. Almost (or completely) freezing people to revive them gives a nasty taste to many people. All this assumes that one can hibernate which seems to me just as possible as anti-matter-engines to you. ============================================================================= >I was thinking the pumps and fuel processors, and high energy power systejms >wouldn't weigh as much as the propulsion dishes, tanks, and reinforcing >structure. Those heavy parts would be easier to rebuild in systems from >local ores. Yes, but aren't these high-tech parts? Does an airplane have any low-tech parts (except the chairs)? All these parts have high specifications, also the construction needs to be perfect. >> It's the use of fusion-fuel that causes this, staging is a result of using >> fusion fuel. (Just a minor difference) > >Or any fuel without a much higher power to weight ratio. Do you have a better idea, that I don't know of... :) Timothy From popserver Mon Feb 12 19:06:32 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3896" "Mon" "12" "February" "1996" "11:51:14" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "78" "LIT TC Project (fwd)" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from maroon.tc.umn.edu (root@maroon.tc.umn.edu [128.101.118.21]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA02812 for ; Mon, 12 Feb 1996 10:12:05 -0800 (PST) Received: by maroon.tc.umn.edu; Mon, 12 Feb 96 11:51:26 -0600 Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: LIT TC Project (fwd) Date: Mon, 12 Feb 1996 11:51:14 -0600 (CST) recieved and fwd. please add this person to your LIT mail list. he seems sincere. ---------- Forwarded message ---------- Date: Sun, 11 Feb 1996 17:57:41 -0600 From: L. Parker To: Tex Houston Subject: LIT TC Project Hi Kevin, I am a little new here and have been reading through older postings as fast as I can. So if I duplicate an issue or repeat a question that has already been answered please excuse me. Is there an updated version of Kelly Starks' proposed configuration for Asimov? It seems some major profile changes have been made since he posted it in '94. Have you compared simple solar pumped mechanical lasers to the microwave generators? They would not transmit power as effectively, but it seems to me that they could be massed produced in HUGE numbers to provide more than enough power and remove the need for quite so much magnetic shielding. BTW, I am not sure depending on shielding generated by an external wire mesh dish is such a good idea. As Kelly pointed out in his early design proposal, we don't really know what the composition of interstellar space is. Suppose that just occasionally we run into something bigger than the shield can deflect, or a pocket of denser media which imparts more kinetic energy to the structure than it is capable of abosrbing...might be a good idea to combine both shielding ideas (mass/magnetic) as well as any other built in redundancy we can come up with. Matter of fact, I am not too fond of the idea of the mesh period, too many things can/might/will go wrong with it. Sure would be nice if we could focus magnetic fields over a long (1000 km) distance. That might even allow us to resuscitate the idea of using a RAM scoop. Most of the postings I have read seem to assume a period of coasting in all configurations, why? It would be far simpler to design for continuous 1 G acceleration for the duration of the mission. It might even be agood idea to DESIGN for operation at up to 3 or 4 G for extended periods (Emergency Contingency Planning). Okay, now for some REALLY strange questions... 1) Has anyone calculated the mass density of matter impacting the ship at ..99 c and computed how much and what kinds of primary, secondary, and Cherenkov radiation would be generated? CAN we provide that much shielding? How about blue shifted free radiation? Wouldn't there be a great deal of radiation in the x-ray and gamma ray bands? Can we shield against it? Also remember that at relativistic velocities the event horizon contracts for and aft, concentrating the radiation exposure there. 2) What is the particle density in the various speed regimes? Is there a minimum speed at which the density would become great enough to initiate an EXTERNAL fusion reaction similar to a QED-electric REB plasma rocket (page 11 of Kelly's paper)? Now wouldn't that be neat? An air breathing spaceship! 3) Generally, what is the MAXIMUM particle density we could safely use for acceleration? 4) Generally, what is the maximum particle density we could safely navigate? 5) Can we detect increased particle density ahead of our course by any means, and at sufficient range to allow us to generate enough delta v to avoid it? Twould be a shame to lose the first interstellar mission to a cloud of water vapor! Well, enough for now, I have lots more questions, many of which, like some of these, may not be germane, but what the heck, someone has to ask them! :-} Lee Parker +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + + + Weave a circle 'round him thrice, and close your eyes with holy dread... + + + +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From popserver Mon Feb 12 20:49:43 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5815" "Mon" "12" "February" "1996" "15:42:48" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "121" "Re: LIT TC Project (fwd)" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA15558 for ; Mon, 12 Feb 1996 12:48:48 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA03294; Mon, 12 Feb 96 15:44:49 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI003234; Mon Feb 12 15:43:07 1996 Received: by most (4.1/SMI-4.1) id AA12378; Mon, 12 Feb 96 15:43:04 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma012372; Mon Feb 12 15:42:50 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA29126; Mon, 12 Feb 96 15:42:45 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: lparker@destin.gulfnet.com, Kevin C Houston Cc: interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: LIT TC Project (fwd) Date: Mon, 12 Feb 1996 15:42:48 -0500 Hi Lee, In responce to the message you sent to Kevin. At 11:51 AM 2/12/96, Kevin C Houston wrote: >recieved and fwd. please add this person to your LIT mail list. he seems >sincere. > >---------- Forwarded message ---------- >Date: Sun, 11 Feb 1996 17:57:41 -0600 >From: L. Parker >To: Tex Houston >Subject: LIT TC Project > >Hi Kevin, >I am a little new here and have been reading through older postings as fast >as I can. So if I duplicate an issue or repeat a question that has already >been answered please excuse me. Is there an updated version of Kelly Starks' >proposed configuration for Asimov? It seems some major profile changes have >been made since he posted it in '94. I've been meaning to, but life got in the way. That old draft is very drafty, and needs some correction and updating. You should note though that it is not 'the' ship design, it was my cut at a possible design. My design used Fusion powered drive systems feed from carried fuel and fuel launched ahead of it by a fixed fuel launcher. Some of the ideas listed in their didn't pan out, and the ship itself is not capable of geting to Tau Ceti in a usable periode of time. But a lot of the general systems designs and equipment (hab-deck design, types of exploration ships and equipment, etc..) seem to be the basic concept everyone has tacitly accepted. Thou the others are leaning more toward some sort of microwave powered relativistic drive. Unfortunatly we can't think of one thats likely to work (stoping is a big problem!). In the next draft I hope to upgrade the numbers included in there, add illistrations, and write up associated summary documents for the groups progress to date. (Did you see the draft summary document I sent around?) >Have you compared simple solar pumped mechanical lasers to the microwave >generators? They would not transmit power as effectively, but it seems to me >that they could be massed produced in HUGE numbers to provide more than >enough power and remove the need for quite so much magnetic shielding. How would microwaves vs lasers effect shielding requirements? >BTW, I am not sure depending on shielding generated by an external wire mesh >dish is such a good idea. As Kelly pointed out in his early design proposal, >we don't really know what the composition of interstellar space is. Suppose >that just occasionally we run into something bigger than the shield can >deflect, or a pocket of denser media which imparts more kinetic energy to >the structure than it is capable of abosrbing...might be a good idea to >combine both shielding ideas (mass/magnetic) as well as any other built in >redundancy we can come up with. > >Matter of fact, I am not too fond of the idea of the mesh period, too many >things can/might/will go wrong with it. Sure would be nice if we could focus >magnetic fields over a long (1000 km) distance. That might even allow us to >resuscitate the idea of using a RAM scoop. I'm a little confused. We were considering making the microwave sail/reflector out of mesh, but not the shielding. >Most of the postings I have read seem to assume a period of coasting in all >configurations, why? It would be far simpler to design for continuous 1 G >acceleration for the duration of the mission. It might even be a good idea to >DESIGN for operation at up to 3 or 4 G for extended periods (Emergency >Contingency Planning). In general we have problems generating the thrust needed for continuous G; and since the ship has to drift few the target star system during exploration, we need artificial G anyway. >Okay, now for some REALLY strange questions... > >1) Has anyone calculated the mass density of matter impacting the ship at >.99 c and computed how much and what kinds of primary, secondary, and >Cherenkov radiation would be generated? CAN we provide that much shielding? >How about blue shifted free radiation? Wouldn't there be a great deal of >radiation in the x-ray and gamma ray bands? Can we shield against it? Also >remember that at relativistic velocities the event horizon contracts for and >aft, concentrating the radiation exposure there. > >2) What is the particle density in the various speed regimes? Is there a >minimum speed at which the density would become great enough to initiate an >EXTERNAL fusion reaction similar to a QED-electric REB plasma rocket (page >11 of Kelly's paper)? Now wouldn't that be neat? An air breathing spaceship! > >3) Generally, what is the MAXIMUM particle density we could safely use for >acceleration? > >4) Generally, what is the maximum particle density we could safely navigate? > >5) Can we detect increased particle density ahead of our course by any >means, and at sufficient range to allow us to generate enough delta v to >avoid it? Twould be a shame to lose the first interstellar mission to a >cloud of water vapor! > >Well, enough for now, I have lots more questions, many of which, like some >of these, may not be germane, but what the heck, someone has to ask them! :-} > >Lee Parker > >+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >+ + >+ Weave a circle 'round him thrice, and close your eyes with holy dread... + >+ + >+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Wed Feb 14 18:58:03 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4417" "Wed" "14" "February" "1996" "08:25:57" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "108" "Re: " "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA25948 for ; Wed, 14 Feb 1996 05:34:36 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA04813; Wed, 14 Feb 96 08:29:02 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004726; Wed Feb 14 08:26:48 1996 Received: by most (4.1/SMI-4.1) id AA02517; Wed, 14 Feb 96 08:26:44 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002510; Wed Feb 14 08:25:59 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA15965; Wed, 14 Feb 96 08:25:55 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-Priority: 2 (High) From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: lparker@destin.gulfnet.com Cc: Nick@panda1.demon.co.uk, KellySt@aol.com, bmansur@oc.edu, David@interworld.com, jim@bogie2.bio.purdue.edu, rddesign@wolfenet.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: Date: Wed, 14 Feb 1996 08:25:57 -0500 At 5:46 PM 2/13/96, L. Parker wrote: >Nick, > >I have been thinking about the problem of changing the configuration of the >sweep field to deceleration mode and have an idea to suggest. > >Suppose that we make a few minor :-) changes: > >1) Design it to be double ended with respect to the Lineac (Stellarator?) so >that either end can be intake or exhaust. > >2) Mount the sweep field equipment generators on a ring at each end of the >ship, slightly ahead of (or behind) the actual inlet/outlet. > >By doing this, we can use the field at the front (?) end during acceleration >and the field at the back during deceleration. With the direction of travel >being to the left in both cases, this would appear like this in acceleration: > > \ > \ > \--------- > | > --------- > / > / > / > >and like this during deceleration: > > \ > \ > \ > ---------- > | > ---------- > / > / > / > >See the attached JPEG file for design modification. > >During the deceleration phase, the field at the front can be reduced and >inverted to maintain a shield for the ship while still funneling reaction >mass into the rear ring. The rear sweep field will provide braking like a >parachute whether or not you actually run the engines. In fact, if you go >into deceleration and don't run the engines for a while, you could actually >replinish onboard reaction mass by simply scooping it up. Ah, we'ld always been assuming the accelerator core could work eaither way (thou only the frount would have a scoop). I'm afriad the double scoops are more trouble then they are worth. Especiall given that we were talking about scops/sails hundreds to thousands of kilometers across. >AS was pointed out (by you?) now it is simply a matter of reversing the >current flow. Looking at drag issues and field dynamics you would want the >ability to "tune" the fields by changing their size and density, do a >particle/mass density calculation on H+ ions entering a ONE sq/km scoop at >.99 c and I think you will find something like 3e14 PARTICLES PER SECOND >(not adjusted for relativistic effects). You MIGHT want to be able to change >this! > >While this CAN be done with wire mesh, it would be far better if we could do >it with fields alone. Then we could dispense with the doble ended design >entirely and probably increase the scoop efficiency as well. As was pointed >out in relation to one of your earlier posts, too bad we don't know how... > >Another thought: I have already mentioned this idea to Kelly but maybe you >might want to look at it also. As an alternative to Kevin's beamed Microwave >proposal, suppose we could generate an MHD field externally along the length >of the ship and using a field design similar in shape to the Aurora project The Aurora's don't generate magnetic fields around themselves. The various designs under testing use internal or exteral scramjets and turbo-ramjets. Not MHD thrusters. >aircraft, generate a fusion rocket outside the ship? Sort of a ring around >the ship's middle spaced apart by some distance through which the RM is >funneled by the sweep field and then compressed by MHD fields until it >achieves fusion density and exhausts past a sharp field break that acts as a >venturi. This sounds like a Bussard Ramscoop, which unfortunatly we couldn't build. >Not to change the subject, but was it you who said something about not being >able to use cyclotrons? I believe acceleration does not occur until exhaust.... > >Lee Parker > >Attachment converted: Macintosh HD:Asimov.jpg (JPEG/JVWR) (000087D2) >+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >+ + >+ Weave a circle 'round him thrice, and close your eyes with holy dread... + >+ + >+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Kelly Starks ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Thu Feb 15 04:51:07 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1059" "Wed" "14" "February" "1996" "21:38:32" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "35" "Uh oh :-/" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub2.tc.umn.edu (mhub2.tc.umn.edu [128.101.131.52]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA02318 for ; Wed, 14 Feb 1996 19:40:00 -0800 (PST) Received: from maroon.tc.umn.edu by mhub2.tc.umn.edu; Wed, 14 Feb 96 21:38:34 -0600 Received: by maroon.tc.umn.edu; Wed, 14 Feb 96 21:38:33 -0600 In-Reply-To: <199602141641.IAA05303@moon.sirius.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Patricia Corrigan , interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl, Rikki_&_Bob Myaran , "Edward R. Houston" , kanter@winbright.net Subject: Uh oh :-/ Date: Wed, 14 Feb 1996 21:38:32 -0600 (CST) Here we go... I got this message when I logged in: BEGIN Quote NOTICE (1995-02-14): The www.tc.umn.edu Web service is scheduled to be down this coming Sunday, February 18th, from 8am to 11am. We will be reconfiguring filesystems which will require that the /nlhome hierarchies be unavailable during this time. This will NOT affect www.umn.edu Web service -- only personal web pages. END Quote So what do you think? is http://www.umn.edu/nlhome/m056/hous0042 in trouble? what should I Do? should I 1) stand tall and let them find it. 2) hide it, and put it back later. 3) fold now and let the Censors 'win' your input is hereby sought. Please respond soon Kevin 'Tex' Houston -- If they won't protect the _First_, they won't protect _any_. From popserver Thu Feb 15 04:51:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["230" "Wed" "14" "February" "1996" "22:55:39" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "7" "Re: A new way of DEcelerating" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA03684 for ; Wed, 14 Feb 1996 19:58:14 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id WAA27720; Wed, 14 Feb 1996 22:55:39 -0500 Message-ID: <960214225538_423009001@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: A new way of DEcelerating Date: Wed, 14 Feb 1996 22:55:39 -0500 ??? Maybe I'm tired, but I still don't understand how this thing works. Sounds like if you can keep dumping the excess heart generated (and keep the thing from folding up) it should be a nice mag brake. --- I think? Kelly From popserver Thu Feb 15 04:51:13 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5276" "Wed" "14" "February" "1996" "22:55:59" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "126" "Re: Hands and brains." "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA03732 for ; Wed, 14 Feb 1996 19:58:57 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id WAA02103; Wed, 14 Feb 1996 22:55:59 -0500 Message-ID: <960214225556_423009273@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Hands and brains. Date: Wed, 14 Feb 1996 22:55:59 -0500 Subj: Re: Hands and brains. to: Timothy van der Linden > To Kelly, > > >>So than the final question is what determines the complexity of the > >>connections? > > > >Yes and why it develops. > > I think the latter is clear, being able to use your braincells more > efficient is a clear evolutional advantage. Or did you mean something different? Clear advantage for what. I.E. what pushed us to do that much evolving into our brains and tool making. > >> Ah, but in that experiment they didn't test the isolating properties of > >> greenhouse gasses. They tested the total result. So since greenhouse gasses > >> do keep the heat in (I'm sure that is tested) they should have conlcuded > >> that there probably were some other mechanisms reducing the effect of > >> heating up. (I've seen graphs showing the amount of CO2 rose significantly > >> since 200 ago) > >> For example a higher amount of CO2 increases the growth of plants, so in > >> total they absorb more light and store it in their leaves instead of > >> reflecting it as heat. > > > >To my knowledge no one has tested if "greenhouse gasses" do cause a warming > >of an isolated system. > > I think that experiments have been done many years ago. I've read in several > books what I wrote before: Greenhouse gasses are more opaque planetary > radiation than for solar radiation. > This implies that the volume in which the greenhouse gas is present becomes > warmer than if it was a normal gas. Implies, not proves. Atmosphers have many complex interactions, few of which are well understood. So even if the green gases did block radiation from escaping and kept in heat. Would that cause the system to heat or cool? Would it keep the heat in at night but keep it out durring the day? Would this change cause more cloude cover which would effect the balence (it isn't known if clouds heat or cool). How would global wind patterns change? All this stuff interacts, and no one knows how. So even if they knew what the green gases did, they still couldn't tell what the total effect on the system would be. Best you could do is check records for long term trends over the last 200 year (i.e. industrial revolution time.), but that shows no clear pattern, and the data has more holes than solids. > >Even if they did, it would be irrelavant to the global climtae issue. > > I can't follow that, or are you saying that Earth's atmosphere isn't an > isolated system in this context. See above > >>>Then again, it was only a few years back that > >>>someone showed the greenhouse effect dosen't work in greenhouses. > >> > >>I heard this before but still don't know how they thought a greenhouse > >>worked. > >>Of course the glass walls are much better of keeping the convective heat in > >>than the greenhouse gasses are in keeping the radiative heat in. > > > >Glass, like greenhouse gases is opage to heat but not visible light. So it > >was assumed the light heateed the siol, and the heat couldn't radiate out. > > But why isn't that true then? Or is it because the heat can radiate out but > only not as fast? The solar energy doesn't change in bulk to heat. The glass blocks solar heat as well as soil heat. Above all the heat radiation rates were not the dominent effect in the system. > >Never heard those claims. The worst temp rise claims I hear expected a 1-3 C > >change in the next half century to century. Never heard anyone claim a ..2-.4 > >C per year change. NASA's equipment could detect a .2 degree change over the > >last 25-30 years, but didn't see any change. > > It may well be that my numbers are wrong and should indeed be more like 4 > degrees per century but anyhow, they are an increase. And I heard several > times that the global temperature was increasing (although not necessary > caused by the greenhouse effect). Now I only wonder why NASA's measurement > shows something different than other measurements of which I don't recall > the source. The press and ecogroups often report the temperature increase. Science and climatology reports usualy report inconclusive results. But the press and advocacy groups hate that, so they skip over it. I know that NASA was called on the carpet for reporting their data. Tenb Senator (now vice president) Gore gets a lot of his image for his stance on the environment, and in hearing he got VERY nasty to the NASA guys trying to report facts that made him look like an idiot. So they don't mention it anymore, and the press never really picked up on it. UInless you read the journals (or worked at NASA headquarters ;) ) you'ld never have heard it. > >>>But in an alien environ those isolated patchs here, could be the norm for > >>>the planet. (It would be worth a lot of study, but no one would want to live > >>>there!) > >> > >> Yes, but it would mean they could not have evolved to higher organisms. > > > >Not nessisarily. A complex sizable ecology could evolve complex life forms. > > Just becuse its based on something very weird doesn't change that. > > I meant that higher organisms could not evolutionize in small areas because > there would be not enough food for a population large enough to overcome > inbreading. I was assuming the environments were large scale, even global. Kelly From popserver Thu Feb 15 04:51:45 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["7565" "Wed" "14" "February" "1996" "22:56:09" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "178" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout04.mail.aol.com (emout04.mail.aol.com [198.81.10.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id TAA03791 for ; Wed, 14 Feb 1996 19:59:40 -0800 (PST) Received: by emout04.mail.aol.com (8.6.12/8.6.12) id WAA02219; Wed, 14 Feb 1996 22:56:09 -0500 Message-ID: <960214225609_423009497@emout04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Wed, 14 Feb 1996 22:56:09 -0500 > To Kelly, > > >I wasn't assuming we would be using a propulsion beam, much less build one in > >the target systems. You've pretty wel convinced me that, that isn't > >practical. > > Oh yes, it was Kevin who wants to use it. But you do use it in the next > part, or is that only for a relative short acceleration period? Next part? I list all of them in the summary, but don't assume any of them will be used. My designs only use fusion drives and fuel launchers. > >SETI wasn't expecting to download the output of a couple hundred researchers > >and all there raw data. I know bandwidth is a problem on the hubble and the > >other remote platforms (they use data filtering to skim out the desired > >parts, and everyone prays they selected the right parts) so I assume the > >problem would also exist for a starship. > > OK, could a satellite in a far orbit around TC be a possibility to overcome > the interferring radiation of TC? If we can distinguish big planets from > their Sun many lightyears away, I think we can also distinguish some signals > of a strong satellite in an orbit beyond the TC-analog of Pluto. Possibly, but if we have a hard time even seeing a planet, what luck will we have trying to see and decript a signal? ============================================================================== > > >> Could we really trust such a big machinery to keep on working for > >> several months (if not a year)? > > > >Sure, we have a lot of big mechanical systems experience and the launcher is > >very simple and has very few moving parts. The complex part would be the > >minning and construction parts, and the crews will be around to supervise > >that. > > It may have few moving parts, but so does a rocket engine. How many rocket > engines will be able to work continously for half a year? Rockets have to be light and high powered. For this system the pumps would be closer to city water pumps than rocket turbo pumps. The accelerator would provide the high speed boost, but none of it would move. > I imagine such a launcher as an electromagnetic pipeline say 100 km in > length and 10 cm in diameter. This is about 10 times as long as the > accelerator at CERN. It's diameter is probably many times more. I think we > won't reach much more than .5c because at CERN it takes several 1000 turns > to get the particles to move that fast. I'm not sure if we need a vacuum > assuming we use something like our moon to build the launcher on. But if we > do, it means a lot of moving objects (I'm not sure though how high-vacuum > pumps do work). > On the other hand there is a lot of electronics involved to control al the > machinery. Can we be sure that there won't be a fuse that burns through? (I > assume there won't be any fuses, since they aren't allowed to burn through > anyway) I'm not clear on the requirment for the launcher. Hopefully it won't need to be that long. I don't think we'ld need speed that high because then the ship would get to far away from the launcher before it got that fast. I think beam presision is the main limitation, but I haven't work on it. > To make an anology, could a nuclear reactor work without anyone present, for > half a year? (Limited remote control could be allowed) Some reators do run for years without direct control. (Some like three mile Island ran much better that way ;) ) The big commercial plants need operating, but thats mainly to adjust for power loads. Soviet subs are fairly automated as I remember. And of course the computer power avalible will be a lot more. Of course if they can't be automated, the ship can't go. > Besides all this, building such an accelerator is pretty high tech. And you > are constantly saying that that isn't possible. Accelerators arn't that high tech. At least not if you arn't interested in super high speeds and partical level interactions. Its basically an electromagnetic cannon. ============================================================================== > >> star-system within a small period. If they wanted they could take a few > >> generations. They would be excellent objective observers since they > >> wouldn't > >> know very well what Earth was like. Flying aircrafts perfectly isn't > >> necessary, as long as the flight and landing is reasonable smooth that is > >> enough. > > > >Thats like giving a navy TomCat fighter and mission to someone whos never > >been out of doors, much less in and aircraft, but has played the sim game a > >lot. (The landings should be especiaslly --- colorfull.) > > What I've seen from these simulations, is that they can be quite realistic. > g-forces, ever more perfect visual environments. A few weaks ago I saw that > there where special simulations for landings on a flightdeck (talk about > difficult landings). Maybe the simulations aren't 100% real but I think that > 90% is close enough. The pilots disagree. They can't simulate G fources well at all, and can sometimes give pilots the wrong reflexes in G manuvers. They are excelent for exersizing a pilot in certain things. Bad in others. > >> space colony. And why should a space colony be so significantly more > >> dangerous than a 5 year flight in space? > > > >Because a space colony is a 50-100 year flight through space. Same life > >support needs and risks, just for 10-20 times longer, and with and > >increasingly old and wornout crew and ship. > > Yes, but you would be able to repair or rebuild things. Same in the ship. Besides, how do you repair the crew when they wear out? > >Not if they liked the program. Media generally don't ask many hard questions > >of things they agree with. Look at how little media investigation there has > >been on global warming and greenhouse theories. They are every bit as easy > >to investigate, yet that seldom is done. Certainly my experience at NASA > >confirms that. > > Media also like to tackle plans that seem to look OK. Besides why wouldn't > they like the idea to build a colony there. A colony with no purpose and tremendous expence? Which locks us into frequent perminent suply runs? Which condems its occupants to dramatically shortend lives of hardship? I think they might find more than a few reasons if they want to. >Almost (or completely) freezing > people to revive them gives a nasty taste to many people. All this assumes > that one can hibernate which seems to me just as possible as > anti-matter-engines to you. Hibernation seems to get talked about with harly a wisper of concern in a lot of groups. Frankly I can't understand why. ============================================================================= > > >I was thinking the pumps and fuel processors, and high energy power systejms > >wouldn't weigh as much as the propulsion dishes, tanks, and reinforcing > >structure. Those heavy parts would be easier to rebuild in systems from > >local ores. > > Yes, but aren't these high-tech parts? Does an airplane have any low-tech > parts (except the chairs)? All these parts have high specifications, also > the construction needs to be perfect. Not really, they are just big structural elements. That should be pretty easy to build from local supplies. > >> It's the use of fusion-fuel that causes this, staging is a result of using > >> fusion fuel. (Just a minor difference) > > > >Or any fuel without a much higher power to weight ratio. > > Do you have a better idea, that I don't know of... :) Unles we come up with matter conversion or warp drives, I think thats about it. Kelly From popserver Thu Feb 15 07:25:56 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6327" "Thu" "15" "February" "1996" "00:01:05" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "148" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub2.tc.umn.edu (mhub2.tc.umn.edu [128.101.131.52]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id WAA11741 for ; Wed, 14 Feb 1996 22:02:39 -0800 (PST) Received: from maroon.tc.umn.edu by mhub2.tc.umn.edu; Thu, 15 Feb 96 00:01:06 -0600 Received: by maroon.tc.umn.edu; Thu, 15 Feb 96 00:01:06 -0600 In-Reply-To: <960214225609_423009497@emout04.mail.aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: KellySt@aol.com cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Thu, 15 Feb 1996 00:01:05 -0600 (CST) On Wed, 14 Feb 1996 KellySt@aol.com wrote: > Tim wrote: > > > > > >> Could we really trust such a big machinery to keep on working for > > >> several months (if not a year)? > > > > > >Sure, we have a lot of big mechanical systems experience and the launcher > is > > >very simple and has very few moving parts. The complex part would be the > > >minning and construction parts, and the crews will be around to supervise > > >that. > > > > It may have few moving parts, but so does a rocket engine. How many rocket > > engines will be able to work continously for half a year? > > Rockets have to be light and high powered. For this system the pumps would > be closer to city water pumps than rocket turbo pumps. The accelerator would > provide the high speed boost, but none of it would move. so one of the questions we have to answer, is whether we should leave the launcher in the target system, or take it with us and add the complexity of an maser array. if we take it with us, we can keep it maintained, if we leave it behind, we might save some energy. > > I imagine such a launcher as an electromagnetic pipeline say 100 km in > > length and 10 cm in diameter. This is about 10 times as long as the > > accelerator at CERN. It's diameter is probably many times more. I think we > > won't reach much more than .5c because at CERN it takes several 1000 turns > > to get the particles to move that fast. I'm not sure if we need a vacuum > > assuming we use something like our moon to build the launcher on. But if we > > do, it means a lot of moving objects (I'm not sure though how high-vacuum > > pumps do work). > > On the other hand there is a lot of electronics involved to control al the > > machinery. Can we be sure that there won't be a fuse that burns through? (I > > assume there won't be any fuses, since they aren't allowed to burn through > > anyway) > > I'm not clear on the requirment for the launcher. Hopefully it won't need to > be that long. I don't think we'ld need speed that high because then the ship > would get to far away from the launcher before it got that fast. I think > beam presision is the main limitation, but I haven't work on it. Tim, why not have a torroidal accelerator with a straight aiming track? The particles could go around the track many times before being thrown out into space. That would make it a smaller device > > Do you have a better idea, that I don't know of... :) > > Unles we come up with matter conversion or warp drives, I think thats about > it. Okay, So i see three semi-respectable drive systems. each of which needs some more work to be productive, each of which requires some technology that we don't have yet, or we can't agree when we might have. 1) The fusion RAIR: Pros: we are closer to fusion than to the next two ideas. Fairly low energy. would have military applications (i.e. the government would fund it) moderate heat load/low rad loaad depending on fuel cycle Cons (basic to the design, for which no reasonable tech solution exits) Slower. even if it gets up to .75 C, will add many years to a flight. and the design only calls for .5 C. requires many hundred tons of relatively rare atoms ( i.e. Li, He, Be,) Or a better Fusion pathway that uses Hydrogen. Tech Limitations: a "Fuel Launcher" (whatever that is) capable of keeping a tight beam of fusion fuel pellets (or gas) on course for .5 to 1 Light-years. Must be re-built in target sytem. Must be automated. 2) the MARS: (SOL > {maser sail} > mid-way point > {Lineac drive} > TC) Build maser array (SOL < {maser sail} < mid-way point < { Maser Sail } < TC) Pros: Allows for continuous thrust. a Faster trip. uses no RM to return. maser sail needed for return is easier to repair than fuel launcher. ship will be much lighter during return trip. No Rad load from engine some military applications Cons: (inherent in the design) Gulps and gobbles energy. Has high heat load. The maser array will be much harder to build than a fuel laucher. Due to higher speeds, more shielding will be needed (esp on return trip) Tech limitations: a "maser array" (whatever that is) capable of keeping a tight beam of microwaves on course for 12 light-years. Must be re-built in target system. Must be automated. (N.B. the return maser array can be smaller / only aim to 6 light-years beacuse the Sol transmitter provides braking force allowing ship to dispense with all RM tanks and lineac core) Requires self-reproducing robots. Capable of making solar panels. 3) Anti-matter. Pros. Excellent energy storage. May allow 1 G thrust missions. has military applications. Cons. (inherent in the design) Excellent energy storage. May explode. Has high Rad load. Tech limitations: Manufacturing and storage of anit-matter is still counted in atoms. Okay, did I miss anything? Here's my suggestion: since each design has some technical limitation on it, let's assume we can solve that problem. Kelly gets a fuel launcher, he only has to tell us how far/fast/much it needs to shoot in order to provide the thrust to his rocket. he does not need to prove it works, or justify it's abilities as reasonable. provided the energy costs etc are accounted for. Kelly also gets to use the fusion cycle and reactor of his choice Kevin gets a maser array capable of aiming +/- 1000 Km / 12 L.Y. (really, could be anything, but I think this is reasonable) Kevin also gets self-reproducing robots until he can figure out how to do without them. Reproduction rate/intelligence level will be discussed later. Tim gets the ability to manufacture and store whatever amount of anti-matter is required. If anti-matter is manufactured in target system, 50% effeiciency is assumed (make 1 Kg matter for every Kg Antimatter) E=mC^2. These items then become the minimum tech basis for our designs. They cannot be built until these problems are solved. Since we cannot possibly solve these particular problems here in this forum, let's just assume them for now, and see where this takes us. I will start working on a MARS addition to my home page. Let's try to refine the design of each of these propulsion systems. Kevin Houston -- Fuck the CDA From popserver Thu Feb 15 18:14:24 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1417" "Thu" "15" "February" "1996" "08:22:46" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "55" "Re: Uh oh :-/" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA28351 for ; Thu, 15 Feb 1996 05:29:03 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA16634; Thu, 15 Feb 96 08:25:16 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016586; Thu Feb 15 08:24:03 1996 Received: by most (4.1/SMI-4.1) id AA02595; Thu, 15 Feb 96 08:24:00 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002571; Thu Feb 15 08:22:48 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA26858; Thu, 15 Feb 96 08:22:44 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Patricia Corrigan , interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl, Rikki_&_Bob Myaran , "Edward R. Houston" , kanter@winbright.net, lparker@destin.gulfnet.com Subject: Re: Uh oh :-/ Date: Thu, 15 Feb 1996 08:22:46 -0500 Its not clear if they want to censor contents (thou with the new law they are almost forced to, AOL was worried they'ld be forced out of busness),. They may just be doing systems maintenence. But keeping a copy on floppy would probably be a good idea. Kelly At 9:38 PM 2/14/96, Kevin C Houston wrote: >Here we go... >I got this message when I logged in: > >BEGIN Quote > >NOTICE >(1995-02-14): >The www.tc.umn.edu Web service is scheduled to be down this coming Sunday, >February 18th, from 8am to 11am. We will be reconfiguring filesystems >which will require that the /nlhome hierarchies be unavailable during this >time. > >This will NOT affect www.umn.edu Web service -- only personal web pages. > >END Quote > > >So what do you think? is >http://www.umn.edu/nlhome/m056/hous0042 > >in trouble? >what should I Do? should I > >1) stand tall and let them find it. > >2) hide it, and put it back later. > >3) fold now and let the Censors 'win' > >your input is hereby sought. Please respond soon > >Kevin 'Tex' Houston >-- >If they won't protect the _First_, they won't protect _any_. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Thu Feb 15 18:14:26 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1218" "Thu" "15" "February" "1996" "08:25:47" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "51" "Re: Uh oh :-/" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA28368 for ; Thu, 15 Feb 1996 05:29:56 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA16773; Thu, 15 Feb 96 08:28:34 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016697; Thu Feb 15 08:27:10 1996 Received: by most (4.1/SMI-4.1) id AA02647; Thu, 15 Feb 96 08:27:07 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002619; Thu Feb 15 08:25:48 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA27268; Thu, 15 Feb 96 08:25:45 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: Kevin C Houston Cc: Patricia Corrigan , interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, Kelly Starks x7066 MS 10-39 , KellySt@aol.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl, Rikki_&_Bob Myaran , "Edward R. Houston" , kanter@winbright.net Subject: Re: Uh oh :-/ Date: Thu, 15 Feb 1996 08:25:47 -0500 By the way. I can never get to your home page anyway? Kelly At 9:38 PM 2/14/96, Kevin C Houston wrote: >Here we go... >I got this message when I logged in: > >BEGIN Quote > >NOTICE >(1995-02-14): >The www.tc.umn.edu Web service is scheduled to be down this coming Sunday, >February 18th, from 8am to 11am. We will be reconfiguring filesystems >which will require that the /nlhome hierarchies be unavailable during this >time. > >This will NOT affect www.umn.edu Web service -- only personal web pages. > >END Quote > > >So what do you think? is >http://www.umn.edu/nlhome/m056/hous0042 > >in trouble? >what should I Do? should I > >1) stand tall and let them find it. > >2) hide it, and put it back later. > >3) fold now and let the Censors 'win' > >your input is hereby sought. Please respond soon > >Kevin 'Tex' Houston >-- >If they won't protect the _First_, they won't protect _any_. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Thu Feb 15 18:14:28 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4486" "Thu" "15" "February" "1996" "08:32:00" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "124" "Re: Mag brake" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id FAA28578 for ; Thu, 15 Feb 1996 05:35:35 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA17015; Thu, 15 Feb 96 08:34:29 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI016958; Thu Feb 15 08:33:04 1996 Received: by most (4.1/SMI-4.1) id AA02762; Thu, 15 Feb 96 08:33:02 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002739; Thu Feb 15 08:32:02 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA28259; Thu, 15 Feb 96 08:31:59 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Mag brake Date: Thu, 15 Feb 1996 08:32:00 -0500 I appended my web pages mass in space calculations on the end in case your interested. Oh, the plasma is probably swirling around with the rest of the galaxy in a slightly different orbit that us and the other local stars. Kelly At 10:55 PM 2/14/96, KellySt@aol.com wrote: >-------------------- >Forwarded message: >From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) >To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, >zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, >David@InterWorld.com, bmansur@oc.edu >Date: 96-02-12 12:54:50 EST > >>Are their any numbers on how much power per thrust the magnetic break would >>take? > >I'm not certain if you understood the mechanism. It seems that I didn't >either: > >!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! >! > >Now looking at the formulas again, I notice that the plasma needs to move >traverse to the flightpath and my assumption of towing the wires behind the >ship is probably not right either. They need to be in a network in front of >the ship (the plane of the net is perpendicular to the direction of >movement.) > >!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! >! > >The interstallar plasma is moving, don't ask me why or whereto but the book >says it does. What we do is use the magnetic field component that is >traverse to the velocity of the ship. > > /\ > || >---------------- moving conducting wire > >X O X O X O X O magnetic field lines going up or down or aside > >If the field lines are perpendicular to the direction the wires are moving, >then an electric current will start to flow in these wires. The electric >resistance turns this current into heat and radiates it away in all >directions. All that heat comes from the kinetic energy of the starship and >thus the ship slows down. > > >They use the following formula: > >Drag force= rho V Va A > >rho=mass density of the plasma >V=ships velocity >Va="Alfven" velocity=Sqrt[B^2/(4 Pi rho)]=10 km/sec >B=traverse magnetic field >A=frontal area of the net > >They use also another way of writing: > >Drag force = Sqrt(Dh Dm) > >Dh=hydronamic drag= rho V^2 A (Dh=normal drag due to mass-collisions) >Dm=magnetic drag = A B^2/(4 Pi) > > >This system looks a lot like the solid plate in front of the ship catching >the ISM to decelerate. The book tries to explain that this magnetic sister >may be more usefull due to the size:mass ratio. While one can use thin wires >to make use of the magnetic field, one needs a rather thick plane to stop >fast moving particles. > >By the way, Steve, would it be possible for you to explain how a normal >magnetic scoop could be constructed. > >Timothy Ram Scoop collector 1000 km diameter scoop 200 tons. The speed of light is 300,000 kilometers per second Assuming your moving at 1/3rd the speed of light (100,000 kilometer per second, or 1E10 cm/sec) with a scoop area of 1000 km (pi*R^2=pi(50,000,000cm)^2 = 7.854E15 cm^2). You'd be scooping up the mass in 7.854 E25 cubic centimeters of space. A big question is the composition of interstellar space. A classic assumption is that there is nothing but about 1 atom of hydrogen in a cubic centimeter of space. More recently, people guess it might be less than .054 atoms per cubic centimeter or as many as 10. Even more recently than that (say the last few months) it has been proposed that there may be a lot of long-chain carbon molecules in space. Perhaps 60-200 atoms / molecules. These small, dark, heavy molecules might be the missing 90-99% of the mass of the galaxy (euphemistically called "dark matter"). So far, no one really knows. This is unfortunate, because the composition of the interstellar medium makes a hell of a difference in the design of a RAIR-based starship. Since we don't know one way or the other, let's assume one atom per cubic centimeter at a proton mass of 1.673 E-27 Kg. At 0.333c, using the above design figures, our 1000 km in diameter scoop, scoops up a ram flow of 131.4 grams per second. Note that this number might be off by a factor of 10 or even 100! ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Fri Feb 16 04:51:33 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5742" "Thu" "15" "February" "1996" "23:45:07" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "158" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout10.mail.aol.com (emout10.mx.aol.com [198.81.11.25]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id UAA12070 for ; Thu, 15 Feb 1996 20:48:05 -0800 (PST) Received: by emout10.mail.aol.com (8.6.12/8.6.12) id XAA02108; Thu, 15 Feb 1996 23:45:07 -0500 Message-ID: <960215234506_223455846@emout10.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu Subject: Re: Re: Summary Date: Thu, 15 Feb 1996 23:45:07 -0500 On Wed, 14 Feb 1996 KellySt@aol.com wrote: > Tim wrote: > > > > > >> Could we really trust such a big machinery to keep on working for > > >> several months (if not a year)? > > > > > >Sure, we have a lot of big mechanical systems experience and the launcher > is > > >very simple and has very few moving parts. The complex part would be the > > >minning and construction parts, and the crews will be around to supervise > > >that. > > > > It may have few moving parts, but so does a rocket engine. How many rocket > > engines will be able to work continously for half a year? > > Rockets have to be light and high powered. For this system the pumps would > be closer to city water pumps than rocket turbo pumps. The accelerator would > provide the high speed boost, but none of it would move. so one of the questions we have to answer, is whether we should leave the launcher in the target system, or take it with us and add the complexity of an maser array. if we take it with us, we can keep it maintained, if we leave it behind, we might save some energy. > > I imagine such a launcher as an electromagnetic pipeline say 100 km in > > length and 10 cm in diameter. This is about 10 times as long as the > > accelerator at CERN. It's diameter is probably many times more. I think we > > won't reach much more than .5c because at CERN it takes several 1000 turns > > to get the particles to move that fast. I'm not sure if we need a vacuum > > assuming we use something like our moon to build the launcher on. But if we > > do, it means a lot of moving objects (I'm not sure though how high-vacuum > > pumps do work). > > On the other hand there is a lot of electronics involved to control al the > > machinery. Can we be sure that there won't be a fuse that burns through? (I > > assume there won't be any fuses, since they aren't allowed to burn through > > anyway) > > I'm not clear on the requirment for the launcher. Hopefully it won't need to > be that long. I don't think we'ld need speed that high because then the ship > would get to far away from the launcher before it got that fast. I think > beam presision is the main limitation, but I haven't work on it. ] Tim, why not have a torroidal accelerator with a straight aiming track? ] The particles could go around the track many times before ] being thrown out into space. That would make it a smaller device > > Do you have a better idea, that I don't know of... :) > > Unles we come up with matter conversion or warp drives, I think thats about > it. ] Okay, So i see three semi-respectable drive systems. ] each of which needs some more work to be productive, ] each of which requires some technology that we don't ] have yet, or we can't agree when we might have. 1) The fusion RAIR: Pros: we are closer to fusion than to the next two ideas. Fairly low energy. would have military applications (i.e. the government would fund it) moderate heat load/low rad loaad depending on fuel cycle Cons (basic to the design, for which no reasonable tech solution exits) Slower. even if it gets up to .75 C, will add many years to a flight. and the design only calls for .5 C. requires many hundred tons of relatively rare atoms ( i.e. Li, He, Be,) Or a better Fusion pathway that uses Hydrogen. Tech Limitations: a "Fuel Launcher" (whatever that is) capable of keeping a tight beam of fusion fuel pellets (or gas) on course for .5 to 1 Light-years. Must be re-built in target sytem. Must be automated. ^^^^^^^^^^^^^^^^^^^ Good summary, but what do you mean Military applications? What the hell would the military do with big fixed Electromagnetic cannon? Its just a scaled up version of what they are building now! ] 2) the MARS: (SOL > {maser sail} > mid-way point > {Lineac drive} > TC) ] maser sail needed for return is easier to repair than fuel ] launcher. But is the maser array easier to repair then a fuel launcher? ] 3) Anti-matter. ] Okay, did I miss anything? ] Here's my suggestion: since each design has some technical ] limitation on it, let's assume we can solve that problem. ] Kelly gets a fuel launcher, he only has to tell us how ] far/fast/much it needs to shoot in order to provide the ] thrust to his rocket. he does not need to prove it works, ] or justify it's abilities as reasonable. provided the ] energy costs etc are accounted for. ] Kelly also gets to use the fusion cycle and reactor of ] his choice Ooo, new toys! ;) ] Kevin gets a maser array capable of aiming +/- 1000 Km / 12 L.Y. ] (really, could be anything, but I think this is reasonable) ] Kevin also gets self-reproducing robots until he can ] figure out how to do without them. Reproduction ] rate/intelligence level will be discussed later. ] Tim gets the ability to manufacture and store whatever ] amount of anti-matter is required. If anti-matter is ] manufactured in target system, 50% effeiciency is ] assumed (make 1 Kg matter for every Kg Antimatter) ] E=mC^2. ] These items then become the minimum tech basis for ] our designs. They cannot be built until these problems ] are solved. Since we cannot possibly solve these ] particular problems here in this forum, let's just ] assume them for now, and see where this takes us. ] I will start working on a MARS addition to my home ] page. Let's try to refine the design of each of these ] propulsion systems. ] Kevin Houston Good idea, these do seem to be the only ideas we're talking about anymore, so we might as well write them up. I'm working up a summary list of the drive system ideas, so as more stuff gets filled in we can update it into the summary on LIT. listing the risks assumptions and all that. Kelly From popserver Sat Feb 17 01:43:45 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1894" "Fri" "16" "February" "1996" "10:38:54" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "50" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub1.tc.umn.edu (mhub1.tc.umn.edu [128.101.131.51]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA16341 for ; Fri, 16 Feb 1996 08:40:22 -0800 (PST) Received: from maroon.tc.umn.edu by mhub1.tc.umn.edu; Fri, 16 Feb 96 10:38:55 -0600 Received: by maroon.tc.umn.edu; Fri, 16 Feb 96 10:38:54 -0600 In-Reply-To: <960215234506_223455846@emout10.mail.aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: KellySt@aol.com cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, Lee Parker Subject: Re: Re: Summary Date: Fri, 16 Feb 1996 10:38:54 -0600 (CST) On Thu, 15 Feb 1996 KellySt@aol.com wrote: > > On Wed, 14 Feb 1996 KellySt@aol.com wrote: > > ] Kevin Houston Wrote: > > ] Okay, So i see three semi-respectable drive systems. > ] each of which needs some more work to be productive, > ] each of which requires some technology that we don't > ] have yet, or we can't agree when we might have. > > 1) The fusion RAIR: > > Pros: we are closer to fusion than to the next two ideas. Fairly low energy. > would have military applications (i.e. the government would fund it) > moderate heat load/low rad loaad depending on fuel cycle > > Cons (basic to the design, for which no reasonable tech solution exits) > Slower. even if it gets up to .75 C, will add many years to a flight. > and the design only calls for .5 C. requires many hundred tons of > relatively rare atoms ( i.e. Li, He, Be,) Or a better Fusion pathway that > uses Hydrogen. > > Tech Limitations: a "Fuel Launcher" (whatever that is) capable of > keeping a tight beam of fusion fuel pellets (or gas) on course for .5 to > 1 Light-years. Must be re-built in target sytem. Must be automated. > > ^^^^^^^^^^^^^^^^^^^ > > Good summary, but what do you mean Military applications? What the hell > would the military do with big fixed Electromagnetic cannon? Its just a > scaled up version of what they are building now! > No, you mis-understood, I meant that the military would like to have fusion technology to power subs and space-vessels. The fuel launcher is capable of being built with today's tech. > ] 2) the MARS: (SOL > {maser sail} > mid-way point > {Lineac drive} > TC) > > ] maser sail needed for return is easier to repair than fuel > ] launcher. > > But is the maser array easier to repair then a fuel launcher? No, and I said as much in my message. I think a fuel launcher would be easier to build than a solar array/maser array From popserver Sat Feb 17 01:44:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2584" "Fri" "16" "February" "1996" "13:03:00" "PST" "Brian Mansur" "bmansur@oc.edu" nil "65" "Ionizing Interstellar gases" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: bmansur@oc.edu Received: from einstein.oc.edu (DNS2.OC.EDU [205.143.216.15]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id LAA00520 for ; Fri, 16 Feb 1996 11:09:47 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA12421; Fri, 16 Feb 1996 13:03:05 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <3124F106@mainpobox.oc.edu>; Fri, 16 Feb 96 13:03:02 PST Message-Id: <3124F106@mainpobox.oc.edu> Encoding: 65 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: hous0042 , jim , KellySt , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: Ionizing Interstellar gases Date: Fri, 16 Feb 96 13:03:00 PST Here we go again (sound of two my bits clinking on the table) I was up late a few nights ago, pondering as I sometimes do, just how in the world we are going to get a ram scoop/brake/mag-sail to work without spending unbelievable amounts of energy (which is another problem I was thinking about but don't have time to elaborate much on before I need to go to class. I mentioned before how I read about in 29a the following Begin Excerpt ************************************************** Design Project Newsletter - Week 29a ************************************************** From: segerge@msrc.wpafb.af.mil (GAYLORD E. SEGER) Date: Mon, 6 Feb 1995 08:35:56 +0500 From: "jim" >Jason Cooper writes: > >>Every time I hear of the ramscoop, people keep referring to the scoop as >>a physical thing. How much consideration has been given here to an >>electromagnetic scoop, and a simple ionizing laser to take care of the >>incoming hydrogen? > >Your operative word is "simple." Such a laser would need to have a beam >divergance of nearly one radian in order to ionize even some of the incoming >dust and gas. With some form of magnetic scoop out front of the physical intake, a smaller beam divergence will be neccessary to avoid damaging the scoop. You want ionization to take place in advance of the magnetic scoop, anyway, so there's another reason for a tighter beam. > As the beam diameter reaches that of the intake scoop, the >energy densities would need to be on the order of 10^4 joules per square >centimeter. Assuming an intake scoop diameter of a conservative 100 meters, >the laser would need to be able to output power on the order of 1 terawatt >(10^12) watts. Also bear in mind that most laser processes are only about 10 >percene efficient. This would require that the laser consume 10 terawatts of >electrical power to produce its one terawatt of optical power. Though the >numbers are quick and dirty, they ought be good to an order of magnitude. End Excerpt Ten Terrawatts is way too much power for such a small effect. So I figured, why not fire the beams perpendicular to the direction of the ship? This would act like a laser shield that the particles hit and are ionized by. It saves a lot of power that would otherwise be wasted hitting only 1 atom per cubic centimeter. Of course, I don't know how powerful the beam needs to be to be effective to a distance of 1000 km in any direction. Some know some numbers. If they are too big, we may just have to go without a magnetic scoop/sail. From popserver Sat Feb 17 01:48:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1240" "Sat" "17" "February" "1996" "01:24:16" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "37" "Re: A new way of DEcelerating" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id QAA26545 for ; Fri, 16 Feb 1996 16:25:32 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA15436 (5.67b/IDA-1.5 for ); Sat, 17 Feb 1996 01:24:10 +0100 Message-Id: <199602170024.AA15436@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: A new way of DEcelerating Date: Sat, 17 Feb 1996 01:24:16 +0100 >??? > >Maybe I'm tired, but I still don't understand how this thing works. Sounds >like if you can keep dumping the excess heart generated (and keep the thing >from folding up) it should be a nice mag brake. --- I think? I think that you do understand, but to be sure I will explain it in 3 sentences: The ionize plasma creates magnetic fields that create in their turn an electric current in the array. The electrical resistance in the array then dissipates energy in the form of heat. This method needs a large net: ----------- | | | | | | +-+-+-+-+-+ | | | | | | +-+-+-+-+-+ all lines are several metres apart. | | | | | | ----------- in front or at the back! of the ship. At the back would probably be easier, since it would be a kind of parachute. As said before this method is a cheap way of decelerating, but the ISP (Inter Stellar Plasma) is probably too few and too slow. One could compare it with catching ISmatter, but magnetic coupling is easier than catching matter at high speed. I hope it's clear, if not you can ask me again, but the method won't improve :( Timothy (Answers to the other letters will follow over say 14 hours, at least if my dailback-connection works as it should for a change) From popserver Sat Feb 17 23:17:17 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1143" "Sat" "17" "February" "1996" "15:43:35" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "27" "Re: Re: Summary B" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA07697 for ; Sat, 17 Feb 1996 08:22:27 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA08564 (5.67b/IDA-1.5); Sat, 17 Feb 1996 15:43:29 +0100 Message-Id: <199602171443.AA08564@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 824581993.055 Status: U From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary B Date: Sat, 17 Feb 1996 15:43:35 +0100 To Kevin, >Tim, why not have a torroidal accelerator with a straight aiming track? >The particles could go around the track many times before being thrown >out into space. That would make it a smaller device I assumed that this would increase complexity, since more magnets are needed since the particles want to move in a straight line instead of as circle. Besides this minor problem, I don't think that a torroidal accelerator could accelerate particles continuously but only in small shots. This is because it only can accelerate a localize group of particle moving at one speed. Thus a whole bunch of particle moving at speeds ranging from 1/1000 c to 1/10 c would be a major problem, because they all would move along each other (or worse collide inside the torroid). >Tim gets the ability to manufacture and store whatever amount of >anti-matter is required. If anti-matter is manufactured in target >system, 50% effeiciency is assumed (make 1 Kg matter for every Kg >Antimatter) E=mC^2. I was already looking around for more info about anti-matter. >Fuck the CDA I think that is not allowed to be written... Timothy From popserver Sat Feb 17 23:17:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4479" "Sat" "17" "February" "1996" "15:43:18" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "97" "Re: Hands and brains." "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA07733 for ; Sat, 17 Feb 1996 08:23:31 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA08554 (5.67b/IDA-1.5); Sat, 17 Feb 1996 15:43:11 +0100 Message-Id: <199602171443.AA08554@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 824581993.056 Status: U From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Hands and brains. Date: Sat, 17 Feb 1996 15:43:18 +0100 To Kelly, >> >>So than the final question is what determines the complexity of the >> >>connections? >> > >> >Yes and why it develops. >> >>I think the latter is clear, being able to use your braincells more >>efficient is a clear evolutional advantage. Or did you mean something >>different? > >Clear advantage for what. I.E. what pushed us to do that much evolving into >our brains and tool making. Then we mean the same, only express it different... >> I think that experiments have been done many years ago. I've read in >several >> books what I wrote before: Greenhouse gasses are more opaque planetary >> radiation than for solar radiation. >> This implies that the volume in which the greenhouse gas is present becomes >> warmer than if it was a normal gas. > >Implies, not proves. Atmosphers have many complex interactions, few of which >are well understood. So even if the green gases did block radiation from >escaping and kept in heat. Would that cause the system to heat or cool? > Would it keep the heat in at night but keep it out durring the day? Would >this change cause more cloude cover which would effect the balence (it isn't >known if clouds heat or cool). How would global wind patterns change? I don't understand why you think it keeps the heat out during daylight? As far as I know, it keeps the heat in day AND night. >All this stuff interacts, and no one knows how. So even if they knew what >the green gases did, they still couldn't tell what the total effect on the >system would be. Best you could do is check records for long term trends over >the last 200 year (i.e. industrial revolution time.), but that shows no clear >pattern, and the data has more holes than solids. In this whole discussion I was talking ONLY about the effect of green house gasses. The word cloud never appeared in my writing, indeed it is not known yet what clouds do exactly, but that wasn't what I was discussing. There are probably many effects that compensate for the increased density of greenhouse gasses, but it can be assumed that if the density of the greenhouse gasses gets to big, like on Venus, other effects cannot compensate enough. So we can conclude one thing: the global temperature stays the same, but since greenhouse gasses ALWAYS cause an increase of the temperature there MUST be other effects that work against it. The speculation is that the greenhouse effect can increase to a much higher limit than the counter-effects can. When that happens one talks about a run-away greenhouse effect. >> But why isn't that true then? Or is it because the heat can radiate out but >> only not as fast? > >The solar energy doesn't change in bulk to heat. The glass blocks solar >heat as well as soil heat. Above all the heat radiation rates were not the >dominent effect in the system. Hmm, I don't see what is new. The amounts of reflection don't matter only the reflection DIFFERENCES for solar and soil radiation do matter. I notice that you are talking about solar heat and soil heat, I think that is not correct, you should use solar radiation and soil radiation since both have a very different distribution of the wavelengths (soil has more infrared while the Sun has more ultra violet). >> It may well be that my numbers are wrong and should indeed be more like 4 >> degrees per century but anyhow, they are an increase. And I heard several >> times that the global temperature was increasing (although not necessary >> caused by the greenhouse effect). Now I only wonder why NASA's measurement >> shows something different than other measurements of which I don't recall >> the source. > >The press and ecogroups often report the temperature increase. Science and >climatology reports usualy report inconclusive results. But the press and >advocacy groups hate that, so they skip over it. Ah I see, the well know "media effect". :) >> I meant that higher organisms could not evolutionize in small areas because >> there would be not enough food for a population large enough to overcome >> inbreading. > >I was assuming the environments were large scale, even global. Oh, I thought you were talking about isolated pools, or are these "isolated" pools close enough to "jump" from one to the other. Assuming the geo-recycling of chemicals is global, the creatures using these chemicals would have only relative short period to evolve, since large scale geo-recycling(=vulcans) will exist for a not to long period. Timothy From popserver Sat Feb 17 23:17:22 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6906" "Sat" "17" "February" "1996" "15:43:26" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "152" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id IAA07754 for ; Sat, 17 Feb 1996 08:24:05 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA08559 (5.67b/IDA-1.5); Sat, 17 Feb 1996 15:43:21 +0100 Message-Id: <199602171443.AA08559@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-UIDL: 824581993.057 Status: U From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Sat, 17 Feb 1996 15:43:26 +0100 Kelly, >> OK, could a satellite in a far orbit around TC be a possibility to overcome >> the interferring radiation of TC? If we can distinguish big planets from >> their Sun many lightyears away, I think we can also distinguish some >signals >> of a strong satellite in an orbit beyond the TC-analog of Pluto. > >Possibly, but if we have a hard time even seeing a planet, what luck will we >have trying to see and decript a signal? To see a planet we need spatial RESOLUTION. To receive a signal we don't need an exact position. Although you probably can't see the radio transmitter of your favourite station, you can receive the signal with a simple omni-directional antenna. Your arguement is: TC creates to much radiation along the whole spectrum of wavelength, so that we cannot out-shout it enough to create a signal that makes sence to people in another starsystem. I am not sure if there are no bands that we can use. I think we can find a way around it so that we don't need to shout. This could be done by one or more relay stations. I do agree however, that there may be a problem, but also that we do not know the exact size of it. ============================================================================== >>>Sure, we have a lot of big mechanical systems experience and the launcher is >> >very simple and has very few moving parts. The complex part would be the >> >minning and construction parts, and the crews will be around to supervise >> >that. >> >> It may have few moving parts, but so does a rocket engine. How many rocket >> engines will be able to work continously for half a year? > >Rockets have to be light and high powered. For this system the pumps would >be closer to city water pumps than rocket turbo pumps. The accelerator would >provide the high speed boost, but none of it would move. What I didn't think of the last time, is that it should have to aim. For that it needs some kind of movement. That makes me wonder, how are we going to move such a big launcher. I'm still not sure if you want to place it in space or on some massive rock (planet, asteroid?). >I'm not clear on the requirment for the launcher. Hopefully it won't need to >be that long. I don't think we'ld need speed that high because then the ship >would get to far away from the launcher before it got that fast. I think >beam presision is the main limitation, but I haven't work on it. This length is not only needed to accelerate but also to aim accurately. >> To make an anology, could a nuclear reactor work without anyone present, >> for half a year? (Limited remote control could be allowed) > >Some reators do run for years without direct control. (Some like three mile >Island ran much better that way ;) ) The big commercial plants need >operating, but thats mainly to adjust for power loads. Soviet subs are >fairly automated as I remember. And of course the computer power avalible >will be a lot more. > >Of course if they can't be automated, the ship can't go. I'm still having doubts, and I am a little amazed that you have so much convidence in it, since you are finding it so logical that things break down in a rate too fast to repair by a small community. >> Besides all this, building such an accelerator is pretty high tech. And you >> are constantly saying that that isn't possible. > >Accelerators arn't that high tech. At least not if you arn't interested in >super high speeds and partical level interactions. Its basically an >electromagnetic cannon. Yes, but the size of it is much bigger (1E18 times?) than needed for a few billion atoms per second. It's not the same as adding simple cannons together, since the particles will start to interact and desturb the same fields that accelerate them. ============================================================================== >> What I've seen from these simulations, is that they can be quite realistic. >> g-forces, ever more perfect visual environments. A few weaks ago I saw that >> there where special simulations for landings on a flightdeck (talk about >> difficult landings). Maybe the simulations aren't 100% real but I think >> that 90% is close enough. > >The pilots disagree. They can't simulate G fources well at all, and can >sometimes give pilots the wrong reflexes in G manuvers. They are excelent >for exersizing a pilot in certain things. Bad in others. I don't know why I came with this before: They would probably have some small space cruisers that would be the space equivalent of todays jet-fighters. In these cruisers they could just blank the window (if it has one) and fly in a simulated landscape. So they would have experience in real space and simulated planet flight (and both having real acceleration). I read that NASA is doing test-flights with pilots landing and flying in a plane with no windows, only a computer generated image of the needed information (IR, radar, visual combined). >> >> space colony. And why should a space colony be so significantly more >> >> dangerous than a 5 year flight in space? >> > >> >Because a space colony is a 50-100 year flight through space. Same life >> >support needs and risks, just for 10-20 times longer, and with and >> >increasingly old and wornout crew and ship. >> >> Yes, but you would be able to repair or rebuild things. > >Same in the ship. No, the ship would have much less resources (ores and machinery). >Besides, how do you repair the crew when they wear out? Yes, I know, that is the weakest point of the whole "colony"-idea. >> Media also like to tackle plans that seem to look OK. Besides why wouldn't >> they like the idea to build a colony there. > >A colony with no purpose and tremendous expence? Which locks us into >frequent perminent suply runs? Which condems its occupants to dramatically >shortend lives of hardship? I think they might find more than a few reasons >if they want to. I think that for any flight in the next century there will be lots of reasons not to go. >>Almost (or completely) freezing >> people to revive them gives a nasty taste to many people. All this assumes >> that one can hibernate which seems to me just as possible as >> anti-matter-engines to you. > >Hibernation seems to get talked about with harly a wisper of concern in a lot >of groups. Frankly I can't understand why. I don't understand what you mean: Do you see any public problems with hibernation itself or not? ============================================================================= >> Yes, but aren't these high-tech parts? Does an airplane have any low-tech >> parts (except the chairs)? All these parts have high specifications, also >> the construction needs to be perfect. > >Not really, they are just big structural elements. That should be pretty >easy to build from local supplies. Is that true? I always thought that it needed special bolts an nuts etc. Timothy From popserver Sun Feb 18 21:58:28 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["856" "Sun" "18" "February" "1996" "16:06:27" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "28" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout07.mail.aol.com (emout07.mx.aol.com [198.81.11.22]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA17478 for ; Sun, 18 Feb 1996 13:10:05 -0800 (PST) Received: by emout07.mail.aol.com (8.6.12/8.6.12) id QAA14532; Sun, 18 Feb 1996 16:06:27 -0500 Message-ID: <960218160627_225209980@emout07.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu cc: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, kgstar@most.fw.hac.com Subject: Re: Re: Summary Date: Sun, 18 Feb 1996 16:06:27 -0500 >> Good summary, but what do you mean Military applications? What the hell >> would the military do with big fixed Electromagnetic cannon? Its just a >> scaled up version of what they are building now! > >No, you mis-understood, I meant that the military would >like to have fusion technology to power subs and > space-vessels. The fuel launcher is capable of being > built with today's tech. Oh, your right I didn't understand. >> ] 2) the MARS: (SOL > {maser sail} > mid-way point > {Lineac drive} > TC) >> >> ] maser sail needed for return is easier to repair than fuel >> ] launcher. >> >> But is the maser array easier to repair then a fuel launcher? > No, and I said as much in my message. I think a fuel > launcher would be easier to build than a solar array/maser > array Missed that too. Opps. Ok, no disagreements then. Kelly From popserver Sun Feb 18 21:58:36 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4538" "Sun" "18" "February" "1996" "16:07:35" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "122" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout09.mail.aol.com (emout09.mx.aol.com [198.81.11.24]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA17597 for ; Sun, 18 Feb 1996 13:12:13 -0800 (PST) Received: by emout09.mail.aol.com (8.6.12/8.6.12) id QAA24586; Sun, 18 Feb 1996 16:07:35 -0500 Message-ID: <960218160733_225210363@emout09.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Sun, 18 Feb 1996 16:07:35 -0500 To Timothy van der Linden (I trimed things a bit.) ============================================================================== > What I didn't think of the last time, is that it [fuel launcher] should > have to aim. For that it needs some kind of movement. > That makes me wonder, how are we going to move such > a big launcher. I'm still not sure if you want to place > it in space or on some massive rock (planet, asteroid?). Fourtunately it would have a fixed aim toward Sol. Unfortunately everything in the solar system tumbles. So I expect we'll have to move a big mas to a usable orbut and then stablize it (and possibly gyro stablize part of it). The launchers could be mounted on that and the fuel processors and storage reserved set up on it. (You prep the fuel before you leave, and leave enough extra for the next ship in.) > >I'm not clear on the requirment for the launcher. Hopefully it won't need to > >be that long. I don't think we'ld need speed that high because then the ship > >would get to far away from the launcher before it got that fast. I think > >beam presision is the main limitation, but I haven't work on it. > This length is not only needed to accelerate but also to > aim accurately. You need a 100 km coil to aim 1/4 light year or less? > I'm still having doubts, and I am a little amazed that > you have so much convidence in it [electro-mag fuel launchers], since you are finding > it so logical that things break down in a rate too fast to > repair by a small community. I consider the community will have more complex and less relyable stuff to repair. Electromagnetic launchers are about as simple as we'll get. > >> Besides all this, building such an accelerator is pretty high tech. And you > >> are constantly saying that that isn't possible. > > >Accelerators arn't that high tech. At least not if you arn't interested in > >super high speeds and partical level interactions. Its basically an > >electromagnetic cannon. > Yes, but the size of it is much bigger (1E18 times?) > than needed for a few billion atoms per second. > It's not the same as adding simple cannons together, > since the particles will start to interact and desturb > the same fields that accelerate them. Then package every E18th set of particals into a fuel packet canister. ============================================================================== > I don't know why I came with this before: They would probably have some > small space cruisers that would be the space equivalent of todays > jet-fighters. In these cruisers they could just blank the window (if it has > one) and fly in a simulated landscape.---- Thats a little involved. I'm not sure if it would work. Certainly ground ops training is out, but that might get you trained enough to operate the flyiers. > >> >> space colony. And why should a space colony be so significantly more > >> >> dangerous than a 5 year flight in space? > >> > > >> >Because a space colony is a 50-100 year flight through space. Same life > >> >support needs and risks, just for 10-20 times longer, and with and > >> >increasingly old and wornout crew and ship. > >> > >> Yes, but you would be able to repair or rebuild things. > > > >Same in the ship. > No, the ship would have much less resources (ores and > machinery). The ship would have identical machinery (it would have to carry it eiather way), I'm not really sure of the extra ore would make a big difference. > >>Almost (or completely) freezing > >> people to revive them gives a nasty taste to many people. All this assumes > >> that one can hibernate which seems to me just as possible as > >> anti-matter-engines to you. > > > >Hibernation seems to get talked about with harly a wisper of concern in a lot > >of groups. Frankly I can't understand why. > I don't understand what you mean: Do you see any > public problems with hibernation itself or not? Starngly I've never heard much public upset at the idea. ============================================================================= > >> Yes, but aren't these high-tech parts? Does an airplane have any low-tech > >> parts (except the chairs)? All these parts have high specifications, also > >> the construction needs to be perfect. > > >Not really, they are just big structural elements. That should be pretty > >easy to build from local supplies. > Is that true? I always thought that it needed special bolts an > nuts etc. There are not that hard to build compared to the high tech parts. From popserver Sun Feb 18 21:58:39 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["6050" "Sun" "18" "February" "1996" "16:07:05" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "154" "Re: Hands and brains." "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout08.mail.aol.com (emout08.mx.aol.com [198.81.11.23]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id NAA17634 for ; Sun, 18 Feb 1996 13:14:07 -0800 (PST) Received: by emout08.mail.aol.com (8.6.12/8.6.12) id QAA06786; Sun, 18 Feb 1996 16:07:05 -0500 Message-ID: <960218160704_225210245@emout08.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Hands and brains. Date: Sun, 18 Feb 1996 16:07:05 -0500 > To Kelly, > >> >>So than the final question is what determines the complexity of the > >> >>connections? > >> > > >> >Yes and why it develops. > >> > >>I think the latter is clear, being able to use your braincells more > >>efficient is a clear evolutional advantage. Or did you mean something > >>different? > > > >Clear advantage for what. I.E. what pushed us to do that much evolving into > >our brains and tool making. > Then we mean the same, only express it different... Pretty much. > >> I think that experiments have been done many years ago. I've read in > >several > >> books what I wrote before: Greenhouse gasses are more opaque planetary > >> radiation than for solar radiation. > >> This implies that the volume in which the greenhouse gas is present becomes > >> warmer than if it was a normal gas. > > > >Implies, not proves. Atmosphers have many complex interactions, few of which > >are well understood. So even if the green gases did block radiation from > >escaping and kept in heat. Would that cause the system to heat or cool? > > Would it keep the heat in at night but keep it out durring the day? Would > >this change cause more cloude cover which would effect the balence (it isn't > >known if clouds heat or cool). How would global wind patterns change? > I don't understand why you think it keeps the heat out > during daylight? > As far as I know, it keeps the heat in day AND night. Climatologists don't agree on that. Sun light has a large component in the IR bands. > >All this stuff interacts, and no one knows how. So even if they knew what > >the green gases did, they still couldn't tell what the total effect on the > >system would be. Best you could do is check records for long term trends over > >the last 200 year (i.e. industrial revolution time.), but that shows no clear > >pattern, and the data has more holes than solids. > In this whole discussion I was talking ONLY about the > effect of green house gasses. The word cloud never > appeared in my writing, indeed it is not known > yet what clouds do exactly, but that wasn't what I was > discussing. > There are probably many effects that compensate for > the increased density of greenhouse gasses, but it can > be assumed that if the density of the greenhouse gasses > gets to big, like on Venus, other effects cannot > compensate enough. You keep assuming greenhouse gasses cause global warming. That is an unproven theory. > So we can conclude one thing: the global temperature > stays the same, but since greenhouse gasses ALWAYS > cause an increase of the temperature there MUST be > other effects that work against it. Or we can, we equal validity given the data, assume that 'greenhouse gases' don't cause a temperature rise, since no rise has occured after largescale introduction of those gases to the atmosphere. We don't know! Not knowing makes bad press, but its honest science. > The speculation is that the greenhouse effect can > increase to a much higher limit than the counter-effects > can. When that happens one talks about a run-away > greenhouse effect. A speculation that was thought up after it was agreed that the globe isn't warming. Greenhouse advocates, who previously all agreed that data would show it was warming, then thought up a new theory to explain why they were right, but were early. Again, no data exists to prove their theory. > >> But why isn't that true then? Or is it because the heat > >> can radiate out but only not as fast? > > > > The solar energy doesn't change in bulk to heat. The > > glass blocks solar heat as well as soil heat. Above > > all the heat radiation rates were not the > > dominent effect in the system. > Hmm, I don't see what is new. The amounts of reflection > don't matter only the reflection DIFFERENCES for solar > and soil radiation do matter. And I said the differnces didn't cause the so called 'greenhouse effect'. I.E. the reflection of heat (from solar heated soil) back into the green house, seemed to be matched by the amount of solarheat reflected away from the green house. > I notice that you are talking about solar heat and soil > heat, I think that is not correct, you should use solar > radiation and soil radiation since both have a very > different distribution of the wavelengths (soil has > more infrared while the Sun has more ultra violet). Solar heat would by definition be the IR band of sunlight. your nit picking. > >> It may well be that my numbers are wrong and should indeed be more like 4 > >> degrees per century but anyhow, they are an increase. And I heard several > >> times that the global temperature was increasing (although not necessary > >> caused by the greenhouse effect). Now I only wonder why NASA's measurement > >> shows something different than other measurements of which I don't recall > >> the source. > > >The press and ecogroups often report the temperature increase. Science and > >climatology reports usualy report inconclusive results. But the press and > >advocacy groups hate that, so they skip over it. > Ah I see, the well know "media effect". :) Like they say, 'Good news, isn't news.' > >> I meant that higher organisms could not evolutionize in small areas because > >> there would be not enough food for a population large enough to overcome > >> inbreading. > > >I was assuming the environments were large scale, even global. > Oh, I thought you were talking about isolated pools, or > are these "isolated" pools close enough to "jump" from > one to the other. I was talking about non isolated pools, or global ecosheres. > Assuming the geo-recycling of chemicals is global, > the creatures using these chemicals would have only > relative short period to evolve, since large scale > geo-recycling(=vulcans) will exist for a not to long period. Why do you asume that? Vulcanism on Earth is a localized and infrequent phenominon, but other bodies in this solar system (like Venus or one of the jovian moons) it seems almost constant. From popserver Sun Feb 18 21:58:48 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1629" "Sun" "18" "February" "1996" "13:41:49" "-0800" "Ric Rddesign Denisse Hedman" "rddesign@wolfenet.com" nil "48" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: rddesign@wolfenet.com Received: from wolfe.net (mail1.wolfe.net [204.157.98.11]) by caritas.efn.org (8.7.3/8.7.2) with ESMTP id NAA19290 for ; Sun, 18 Feb 1996 13:42:42 -0800 (PST) Received: from rddesign.wolfenet.com (sea-ts4-p42.wolfenet.com [204.157.100.96]) by wolfe.net (8.7.3/8.7) with SMTP id NAA28437; Sun, 18 Feb 1996 13:41:49 -0800 (PST) Message-Id: <199602182141.NAA28437@wolfe.net> X-Sender: rddesign@wolfenet.com X-Mailer: Windows Eudora Version 1.4.5 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: rddesign@wolfenet.com (Ric & Denisse Hedman) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, David@InterWorld.com, bmansur@oc.edu, T.L.G.vanderLinden@student.utwente.nl, lparker@destin.gulfnet.com Subject: Re: Re: Summary Date: Sun, 18 Feb 1996 13:41:49 -0800 (PST) As you all know I haven't put more than two cents worth into this discussion, mainly because most of it is far above my head. But.... What have we found out about our different propulsion systems? ( I think we have found out we don't really have one) How are we going to stop this bugger? (Short of carrying all our reaction mass/fuel, we probably can't) Can we build any of these systems? ( Probably a few but not to reach the speeds we want) I think you all are really trying very hard to come up with a means to move and stop this thing. I hope all of you can show me, (in laymans trems) that I am wrong on all these points. Next>>>> Once we come up with something we can all agree on.... then what??? Where do we go from there?? Ric >>> Good summary, but what do you mean Military applications? What the hell >>> would the military do with big fixed Electromagnetic cannon? Its just a >>> scaled up version of what they are building now! >> > >>No, you mis-understood, I meant that the military would >>like to have fusion technology to power subs and >> space-vessels. The fuel launcher is capable of being >> built with today's tech. > >Oh, your right I didn't understand. > >>> ] 2) the MARS: (SOL > {maser sail} > mid-way point > {Lineac drive} > TC) >>> >>> ] maser sail needed for return is easier to repair than fuel >>> ] launcher. >>> >>> But is the maser array easier to repair then a fuel launcher? > >> No, and I said as much in my message. I think a fuel >> launcher would be easier to build than a solar array/maser >> array > >Missed that too. Opps. > >Ok, no disagreements then. > >Kelly > > From popserver Mon Feb 19 09:39:37 GMT 1996 X-VM-v5-Data: ([nil nil nil nil t nil nil nil nil] ["166" "Mon" "19" "February" "1996" "01:48:07" "-0800" "Chris Hunt" "chrish@efn.org" "<31284757.1A79@efn.org>" "7" "Re: _The Diamond Age_" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: chrish@efn.org Received: from Pchrish.efn.org (dynip12.efn.org [204.214.97.12]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id BAA24973 for ; Mon, 19 Feb 1996 01:37:38 -0800 (PST) Message-ID: <31284757.1A79@efn.org> Organization: Deepsky Operations X-Mailer: Mozilla 2.0 (Win95; I) MIME-Version: 1.0 References: <199602190933.BAA21764@tzadkiel.efn.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Chris Hunt To: Steve VanDevender Subject: Re: _The Diamond Age_ Date: Mon, 19 Feb 1996 01:48:07 -0800 Steve VanDevender wrote: > > And you thought _Snow Crash_ was wild and interesting. > > I'm only half done. It feels like I've read a whole book already. Author? From popserver Mon Feb 19 21:49:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4181" "Mon" "19" "February" "1996" "19:23:28" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "103" "Re: Hands and brains." "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA28967 for ; Mon, 19 Feb 1996 12:41:06 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA19089 (5.67b/IDA-1.5); Mon, 19 Feb 1996 19:23:27 +0100 Message-Id: <199602191823.AA19089@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Hands and brains. Date: Mon, 19 Feb 1996 19:23:28 +0100 Kelly, >> I don't understand why you think it keeps the heat out >> during daylight? >> As far as I know, it keeps the heat in day AND night. > >Climatologists don't agree on that. Sun light has a large component in the >IR bands. Yes, I know, but "earth-light" is even more intense in that band. (more intense relative to the sunlight that finds it way to the soil) >> In this whole discussion I was talking ONLY about the >> effect of green house gasses. The word cloud never >> appeared in my writing, indeed it is not known >> yet what clouds do exactly, but that wasn't what I was >> discussing. >> There are probably many effects that compensate for >> the increased density of greenhouse gasses, but it can >> be assumed that if the density of the greenhouse gasses >> gets to big, like on Venus, other effects cannot >> compensate enough. > >You keep assuming greenhouse gasses cause global warming. That is an >unproven theory. No, I keep assuming that greenhouse gasses do keep the heat in and I've never heard (except from you) that it keeps the heat out or has no effect at all. >> So we can conclude one thing: the global temperature >> stays the same, but since greenhouse gasses ALWAYS >> cause an increase of the temperature there MUST be >> other effects that work against it. > >Or we can, we equal validity given the data, assume that 'greenhouse gases' >don't cause a temperature rise, since no rise has occured after largescale >introduction of those gases to the atmosphere. We don't know! Not knowing >makes bad press, but its honest science. You are saying that greenhouse gasses don't exist, or in other words there are no gasses that have a higher reflectivity for IR-light than for visible and UV-light. >> The speculation is that the greenhouse effect can >> increase to a much higher limit than the counter-effects >> can. When that happens one talks about a run-away >> greenhouse effect. > >A speculation that was thought up after it was agreed that the globe isn't >warming. Indeed, it should heat up because that was what the data collected from experiments with greenhousgasses showed. >Greenhouse advocates, who previously all agreed that data would >show it was warming, then thought up a new theory to explain why they were >right, but were early. Again, no data exists to prove their theory. Suppose you know that a mass falls, because you've done many experiments. Now you see a mass and it is not falling. How is that possible? Well there is only one solution you say, the theory and experiments must be wrong somewhere. NO, there are some simple solutions, it could be that the mass is hanging on a wire or that the mass is lying on a table. >> Hmm, I don't see what is new. The amounts of reflection >> don't matter only the reflection DIFFERENCES for solar >> and soil radiation do matter. > >And I said the differnces didn't cause the so called 'greenhouse effect'. > I.E. the reflection of heat (from solar heated soil) back into the green >house, seemed to be matched by the amount of solarheat reflected away from >the green house. I assume that do mean the absolute amount of reflected heat and not the reflection coefficient. Is it a coincidence that these absolute amounts are equal? I now don't understand anymore why does it become warm in a greenhouse? >> Ah I see, the well know "media effect". :) > >Like they say, 'Good news, isn't news.' In our family we always say, no news is good news. >> Assuming the geo-recycling of chemicals is global, >> the creatures using these chemicals would have only >> relative short period to evolve, since large scale >> geo-recycling(=vulcans) will exist for a not to long period. > >Why do you asume that? Vulcanism on Earth is a localized and infrequent >phenominon, but other bodies in this solar system (like Venus or one of the >jovian moons) it seems almost constant. I hadn't thought of Io which has vulcanism due to tidal-forces and strong magnetic fields. About Venus, I'm not completely sure but there are only few vulcanos there. So indeed, Io which I hadn't thought of, could sustain non-photosyntetic life for a long time. Timothy From popserver Mon Feb 19 21:49:34 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4762" "Mon" "19" "February" "1996" "19:23:22" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "118" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id MAA29092 for ; Mon, 19 Feb 1996 12:42:47 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AB19050 (5.67b/IDA-1.5); Mon, 19 Feb 1996 19:22:51 +0100 Message-Id: <199602191822.AB19050@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Mon, 19 Feb 1996 19:23:22 +0100 >To Timothy van der Linden > >(I trimed things a bit.) I don't mind, if I forgot something I've my older letters. ============================================================================== >Fourtunately it would have a fixed aim toward Sol. Unfortunately everything >in the solar system tumbles. So I expect we'll have to move a big mas to a >usable orbut and then stablize it (and possibly gyro stablize part of it). > The launchers could be mounted on that and the fuel processors and storage >reserved set up on it. (You prep the fuel before you leave, and leave enough >extra for the next ship in.) As said before, even if the launcher is 100 metres in length it still may be difficult. The best thing we could do is search for a big asteroid which has no own-rotation and is in a far orbit from it's sun (and thus moves not much during a few months). >> >I'm not clear on the requirment for the launcher. Hopefully it won't need >to >> >be that long. I don't think we'ld need speed that high because then the >ship >> >would get to far away from the launcher before it got that fast. I think >> >beam presision is the main limitation, but I haven't work on it. > >> This length is not only needed to accelerate but also to >> aim accurately. > >You need a 100 km coil to aim 1/4 light year or less? Lets see: d=the diametre of the accelerator tube l=length of the accelerator maximum angle of deviation: Tan(theta)=d/l maximum deviation after 1/4ly : 1/4 ly * Tan(theta) = 1/4 ly * d/l using d=0.1, l=1E5, 1 ly=9.46E15 m deviation = 0.25*9.46E15*0.01/1E5=2.4E9 m This deviation is too much, so even a longer pipe should be needed, or a smaller diametre, but the latter has a limit since it needs to exhaust a minimum amount of mass per second. Maybe I've forgotten something, but I don't see what it could be, maybe a torroidal accelerator is better after all. >> Yes, but the size of it is much bigger (1E18 times?) >> than needed for a few billion atoms per second. >> It's not the same as adding simple cannons together, >> since the particles will start to interact and desturb >> the same fields that accelerate them. > >Then package every E18th set of particals into a fuel packet canister. That's like extending a rifle to shoot an big asteroid instead of a bullet (that's only 1E10). I'm not pointing to the extra energy needed, but just to the fact that things cannot be enlarged without changing completely. ============================================================================== >> I don't know why I came with this before: They would probably have some >> small space cruisers that would be the space equivalent of todays >> jet-fighters. In these cruisers they could just blank the window (if it has >> one) and fly in a simulated landscape.---- > >Thats a little involved. I'm not sure if it would work. Certainly ground ops >training is out, but that might get you trained enough to operate the >flyiers. What do you mean by ground ops? Riding vehicles should be easier to simulate since there would be no difficult g-forces to simulate. If you mean hands on field work then indeed it may be a bit more difficult, but a single generation crew would have to become used to that too after being out for 5 to 10 years. >>>Same in the ship. >> >> No, the ship would have much less resources (ores and >> machinery). > >The ship would have identical machinery (it would have to carry it eiather >way), I'm not really sure of the extra ore would make a big difference. I was assuming they could extend=build new tools when they arrived (eg. large, low-tech equipment like steel-rollers) >> I don't understand what you mean: Do you see any >> public problems with hibernation itself or not? > >Starngly I've never heard much public upset at the idea. I think that is because so far no one has been recovered after being freezed in, most people think that it is impossible to revive a person either because of religious and/or technical reasons. Of course there may be other methods of hibernation that are less drastic, although probably all methods mean that people should be in a deep coma. I wonder if the media likes the idea of killing people just so far that they are continiously on the stairway to heaven. ============================================================================= >>>Not really, they are just big structural elements. That should be pretty >>>easy to build from local supplies. > >>Is that true? I always thought that it needed special bolts an >>nuts etc. > >There are not that hard to build compared to the high tech parts. OK, I see that. But is it that difficult to extend the equipment from making bolts with a precision of 1/1000 mm to making a micro chip? Tim From popserver Wed Feb 21 20:12:16 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1012" "Wed" "21" "February" "1996" "19:47:51" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "25" "Greenhouse effect" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl ([130.89.220.2]) by caritas.efn.org (8.7.3/8.7.2) with SMTP id KAA20317 for ; Wed, 21 Feb 1996 10:49:08 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA16801 (5.67b/IDA-1.5 for ); Wed, 21 Feb 1996 19:47:40 +0100 Message-Id: <199602211847.AA16801@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Greenhouse effect Date: Wed, 21 Feb 1996 19:47:51 +0100 Hello Kelly, I was looking on the web for more info about the greenhouse effect, I found the next 2 pages quite clear: Bad Greenhouse (From a meteorology professor) http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html Greenhouse basics (From CSIRO) http://www.erin.gov.au/portfolio/esd/climate/grenbasi.html When reading them, I found that both stated that greenhouse gasses do heat the Earth. The first page also explains the difference between a glass-greenhouse and the (enhanced) greenhouse effect in the atmosphere. The author of the first page does not make clear why the greenhouse gets warmer, he only says that the prevented-convection plays the major role. But then still the heat-energy has to come from somewhere. I still assume this has to do with the glass being less reflective for solar radiation than for soil radiation (just as you wrote before) and that the amount of solar-heat reflected is slightly less than the amount of reflected soil-heat (unlike what you wrote before). Timothy From popserver Fri Feb 23 02:21:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["255" "Thu" "22" "February" "1996" "20:07:11" "-0500" "David Levine" "David@interworld.com" nil "11" "Re: Recycling/AI and super human computers" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: David@interworld.com Received: from www.interworld.com (www.InterWorld.Com [165.254.130.4]) by caritas.efn.org (8.7.4/8.7.2) with ESMTP id RAA26648 for ; Thu, 22 Feb 1996 17:09:00 -0800 (PST) Received: from hal ([165.254.130.90]) by www.interworld.com (post.office MTA v1.9.3 ID# 0-11464) with SMTP id AAA375; Thu, 22 Feb 1996 20:12:00 -0500 Message-ID: <312D133F.1C11@interworld.com> Organization: InterWorld, Really Cool Stuff Division X-Mailer: Mozilla 2.0 (WinNT; I) MIME-Version: 1.0 References: <312D2A05@mainpobox.oc.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: David@interworld.com (David Levine) To: Brian Mansur CC: hous0042 , jim , Kelly Starks , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: Re: Recycling/AI and super human computers Date: Thu, 22 Feb 1996 20:07:11 -0500 Brian Mansur wrote: > I suggest we send this one to the Big E for immediate transmission to the > known universe. Sorry, "Big E"? BTW, you may want to use some method of separating your own material from material you are referencing in an email. David From popserver Fri Feb 23 02:22:00 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1908" "Thu" "22" "February" "1996" "19:14:00" "PST" "Brian Mansur" "bmansur@oc.edu" nil "48" "Re: Re: Summary" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: bmansur@oc.edu Received: from einstein.oc.edu (DNS2.OC.EDU [205.143.216.15]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id RAA27110 for ; Thu, 22 Feb 1996 17:15:25 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA02934; Thu, 22 Feb 1996 19:12:38 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <312D309A@mainpobox.oc.edu>; Thu, 22 Feb 96 19:12:26 PST Message-Id: <312D309A@mainpobox.oc.edu> Encoding: 49 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: bmansur , David , hous0042 , jim , KellySt , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: Re: Re: Summary Date: Thu, 22 Feb 96 19:14:00 PST ---------- From: KellySt To: T.L.G.vanderLinden; stevev; jim; zkulpa; hous0042; rddesign; David; bmansur Subject: Re: Re: Summary Date: Wednesday, February 14, 1996 10:56PM > To Kelly, > > >I wasn't assuming we would be using a propulsion beam, much less build one in > >the target systems. You've pretty wel convinced me that, that isn't > >practical. > > Oh yes, it was Kevin who wants to use it. But you do use it in the next > part, or is that only for a relative short acceleration period? >Next part? I list all of them in the summary, but don't assume any of them >will be used. My designs only use fusion drives and fuel launchers. Interjecting an idea here: isn't our ion rocket basically a superpowerful ion accelerator already? If so, why don't we leave it at Tau Ceti and have it fire a relativistic particle beam at a magnetic sail attached to our ship. The way we've been talking, the ion rocket should be powerful enough to do the job. We just need to park it on a heavy but slow moving Kupier object. Earth can slow us using the same system. For some reason, I don't think its that easy ;( On the other hand, powering shouldn't be such a problem if we bring or build a maser array and let Earth beam power. ( did I just repeat something from a weeks old response to this letter?). Of course, if we can get that to happen, why not just use the maser array to directly power the accelerator as a rocket as Kevin wanted to do in the first place? On the other hand again, using this system, we don't have to worry about the engineering aspects of buiding a microwave antenna that can withstand the radiation/dust wear and tear of relativistic flight not to mention the g-force stresses. A mag-sail should be easier since it is just a bundle of superconductive wires that we could recycle and reweave into a sail. I'm going to shut up for a while now. Brian From popserver Fri Feb 23 07:06:55 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2367" "Fri" "23" "February" "1996" "00:47:55" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "62" "" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id VAA17143 for ; Thu, 22 Feb 1996 21:50:31 -0800 (PST) Received: by emout05.mail.aol.com (8.6.12/8.6.12) id AAA18693; Fri, 23 Feb 1996 00:47:55 -0500 Message-Id: <199602230547.AAA18693@emout05.mail.aol.com> From: KellySt@aol.com Apparently-To: T.L.G.vanderLinden@student.utwente.nl Apparently-To: stevev@efn.org Apparently-To: jim@bogie2.bio.purdue.edu Apparently-To: zkulpa@zmit1.ippt.gov.pl Apparently-To: hous0042@maroon.tc.umn.edu Apparently-To: rddesign@wolfenet.com Apparently-To: David@interworld.com Apparently-To: bmansur@oc.edu Apparently-To: lparker@destin.gulfnet.com Date: Fri, 23 Feb 1996 00:47:55 -0500 Linden > Kelly, > >> I don't understand why you think it keeps the heat out > >> during daylight? > >> As far as I know, it keeps the heat in day AND night. > > > >Climatologists don't agree on that. Sun light has a large component in the > >IR bands. > Yes, I know, but "earth-light" is even more intense in that > band. > (more intense relative to the sunlight that finds it way > to the soil) No sunlight is hotter in the IR band, and your not talking about the amount that gets to the ground, your talking about what hits the top of the atmosphere. IR reflective gasses would reflect that back out. Thus lowering the solar heat gain. Thus lowering the Earth surface temp during the day. > >> In this whole discussion I was talking ONLY about the > >> effect of green house gasses. The word cloud never > >> appeared in my writing, indeed it is not known > >> yet what clouds do exactly, but that wasn't what I was > >> discussing. > >> There are probably many effects that compensate for > >> the increased density of greenhouse gasses, but it can > >> be assumed that if the density of the greenhouse gasses > >> gets to big, like on Venus, other effects cannot > >> compensate enough. > > > >You keep assuming greenhouse gasses cause global warming. That is an > >unproven theory. > No, I keep assuming that greenhouse gasses do keep the > heat in and I've never heard (except from you) that it > keeps the heat out or has no effect at all. Sorry. How could it keep Earth heat in without keeping some solar heat out? > You are saying that greenhouse gasses don't exist, or in > other words there are no gasses that have a higher > reflectivity for IR-light than for visible and UV-light. No, I'm saying that introducing IR reflective gas wouldn't nessisarily heat up a planet that got most of its surface temp from outside sources. Given that a lot of IR reflective gas has been added to the atmosphere without changing the temp, and no one has a coherent explanation for how it would increase the temp, and the whole idea is vigorously debated, I'ld say it seems like a dud theory. > I now don't understand anymore why does it become warm > in a greenhouse? The glass keeps the cold wind out and is a slight insulator. It only works if its not really cold, and theirs still a lot of sunlight to warm it up in the day time. From popserver Fri Feb 23 07:06:58 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4404" "Fri" "23" "February" "1996" "00:48:07" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "113" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id VAA17190 for ; Thu, 22 Feb 1996 21:51:14 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id AAA22430; Fri, 23 Feb 1996 00:48:07 -0500 Message-ID: <960223004806_429571319@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Fri, 23 Feb 1996 00:48:07 -0500 To Timothy van der Linden > >Fourtunately it would have a fixed aim toward Sol. Unfortunately everything > >in the solar system tumbles. So I expect we'll have to move a big mas to a > >usable orbut and then stablize it (and possibly gyro stablize part of it). > > The launchers could be mounted on that and the fuel processors and storage > >reserved set up on it. (You prep the fuel before you leave, and leave enough > >extra for the next ship in.) > As said before, even if the launcher is 100 metres in > length it still may be difficult. The best thing we could > do is search for a big asteroid which has no own-rotation > and is in a far orbit from it's sun (and thus moves not > much during a few months). Everything in fre space tumbles at various speeds and directions. > >You need a 100 km coil to aim 1/4 light year or less? > Lets see: > d=the diametre of the accelerator tube > l=length of the accelerator > maximum angle of deviation: Tan(theta)=d/l ----- Ah, I see your mistake. The angular deflection isn't based on the physical dimentions of the launcher, but on the accuracy and precision of the lateral correction trim thrusting, and deviation sensors. You measure the course of the accelerating packet with lasers and use lateral magnetic or electrostatic fields to adjust the direction. (Its easier if you do this after it leaves the end of the accelerator.) This way the final aim presision is not related to the size of the launcher. > >> Yes, but the size of it is much bigger (1E18 times?) > >> than needed for a few billion atoms per second. > >> It's not the same as adding simple cannons together, > >> since the particles will start to interact and desturb > >> the same fields that accelerate them. > > > >Then package every E18th set of particals into a fuel packet canister. > That's like extending a rifle to shoot an big asteroid > instead of a bullet (that's only 1E10). I'm not pointing > to the extra energy needed, but just to the fact that > things cannot be enlarged without changing completely. Tru the launcher would be more like an electromag cannon then a partical accelerator (and I really wish I had some numbers on the power a mag launcher takes) but that doesn't mean the system would scale up linearly with the size of the load. > >>>Same in the ship. > >> > >> No, the ship would have much less resources (ores and > >> machinery). > > > >The ship would have identical machinery (it would have to carry it eiather > >way), I'm not really sure of the extra ore would make a big difference. > I was assuming they could extend=build new tools when > they arrived (eg. large, low-tech equipment like > steel-rollers) I was assuming the low tech heavy stuff (like structure) would hold together longer than the lighter deatiled stuff (like IC chips and life support systems). > >> I don't understand what you mean: Do you see any > >> public problems with hibernation itself or not? > > > >Starngly I've never heard much public upset at the idea. > I think that is because so far no one has been recovered > after being freezed in, most people think that it is > impossible to revive a person either because of religious > and/or technical reasons. > Of course there may be other methods of hibernation that > are less drastic, although probably all methods mean that > people should be in a deep coma. I wonder if the media > likes the idea of killing people just so far that they > are continiously on the stairway to heaven. Oddly, I think most people assume hibernation is trivial. Lots of animals hybernate for months at a time and stop their motabalism. People have talked about puting crews in hybernation for long trips for so long that its taken for granted by people. ============================================================================= > >>>Not really, they are just big structural elements. That should be pretty > >>>easy to build from local supplies. > > > >>Is that true? I always thought that it needed special bolts an > >>nuts etc. > > > >There are not that hard to build compared to the high tech parts. > OK, I see that. But is it that difficult to extend the > equipment from making bolts with a precision of 1/1000 > mm to making a micro chip? Well there is, but more importantly you wouldn't ever make a bolt that precise for structural or heavy systems use. Kelly From popserver Fri Feb 23 07:07:02 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1012" "Fri" "23" "February" "1996" "00:48:56" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "22" "Re: Greenhouse effect" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout10.mail.aol.com (emout10.mx.aol.com [198.81.11.25]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id VAA17278 for ; Thu, 22 Feb 1996 21:52:47 -0800 (PST) Received: by emout10.mail.aol.com (8.6.12/8.6.12) id AAA14494; Fri, 23 Feb 1996 00:48:56 -0500 Message-ID: <960223004855_429571563@emout10.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Greenhouse effect Date: Fri, 23 Feb 1996 00:48:56 -0500 > The author of the first page does not make clear why > the greenhouse gets warmer, he only says that the > prevented-convection plays the major role. But > then still the heat-energy has to come from somewhere. > I still assume this has to do with the glass being less > reflective for solar radiation than for soil radiation > (just as you wrote before) and that the amount of > solar-heat reflected is slightly less than the > amount of reflected soil-heat (unlike what you wrote > before). Tim I can't beleave you're having this much trouble with this! Green houses heat up in the day when the sun pour a lot of IR on the area. Some of it heats up the inside of the greenhouse and the shelter keeps it from cooling off as fast at night. The same reason greenhouse gasses wouldn't effect daytime temps (well in theory they might cool things), but would warm up the nighttime temps (assuming their were enough of them to make a difference). Could we go back to talking about the star ship? Kelly From popserver Fri Feb 23 14:41:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4052" "Fri" "23" "February" "1996" "08:39:03" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "89" "Re: your mail" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub0.tc.umn.edu (mhub0.tc.umn.edu [128.101.131.50]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id GAA06637 for ; Fri, 23 Feb 1996 06:40:19 -0800 (PST) Received: from maroon.tc.umn.edu by mhub0.tc.umn.edu; Fri, 23 Feb 96 08:39:04 -0600 Received: by maroon.tc.umn.edu; Fri, 23 Feb 96 08:39:04 -0600 In-Reply-To: <199602230547.AAA18693@emout05.mail.aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: KellySt@aol.com cc: interstellar drive group , David@interworld.com, jim@bogie2.bio.purdue.edu, lparker@destin.gulfnet.com, rddesign@wolfenet.com, Steve VanDevender , T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: your mail Date: Fri, 23 Feb 1996 08:39:03 -0600 (CST) On Fri, 23 Feb 1996 KellySt@aol.com wrote: > Linden > > > Kelly, > > > >> I don't understand why you think it keeps the heat out > > >> during daylight? > > >> As far as I know, it keeps the heat in day AND night. > > > > > >Climatologists don't agree on that. Sun light has a large component in > the > > >IR bands. > > > Yes, I know, but "earth-light" is even more intense in that > > band. > > (more intense relative to the sunlight that finds it way > > to the soil) > > No sunlight is hotter in the IR band, and your not talking about the amount > that gets to the ground, your talking about what hits the top of the > atmosphere. IR reflective gasses would reflect that back out. Thus lowering > the solar heat gain. Thus lowering the Earth surface temp during the day. It isn't that sunlight is stronger or lower in the IR bands, it's that earth-light is much much loser in the UV and visible bands. the gases (or whatever) keeps IR from passing, so both solar IR and earthly IR are reflected. The UV and Visible portions of the spectrum usually pass right through and then strike the ground, but the ground doesn't heat up enough to produce visible or UV radiation, so it's sent out as IR. The diving force of the greenhouse is not the difference between earthly IR and Solar IR, it is the difference between solar Visible and UV and Earthly visible and UV (~0) There is very strong data for a temp rise over the last 90-100 years. The question is what caused it. Industrial appologists deny that it has anything to do with them, while environmentalist Luddites want to return to eighteenth century technology. Both are using the available data in the same way that a drunk uses a lampost... not for illumination, but for support. > No, I'm saying that introducing IR reflective gas wouldn't nessisarily heat > up a planet that got most of its surface temp from outside sources. Given yes, it depends on the frequency of the incoming radiation > that a lot of IR reflective gas has been added to the atmosphere without > changing the temp, and no one has a coherent explanation for how it would that is not true. the _has_ been a temp rise over the last 90-100 years. It is small, and it cannot be _proven_ to be caused by the greenhouse gases, but it has occured. > increase the temp, and the whole idea is vigorously debated, I'ld say it Only by those who are afraid to have industrial society collapse around thier ears if the environmentalists win. The Industrialists are right about one thing, we can't stop yet. if we quit burning petrochemicals, we would be starving inside of three months. But the environmentalists are right about something too, we _will_ one day have to stop burning oil, because we are going to run out one day. BTW, Space-based solar energy beamed down by microwave will not solve the greenhouse problem, but will make it worse instead. Energy (microwaves) would be entering the earth's atmosphere, (we'd choose a particularly transparent frequency, to avoid losses) and then be consumed by various items (television, motors, light-bulbs etc) which waste large amounts of energy as heat. The heat would be held in just as it is now, (when talking about a planet, radiation is the only means of heat shedding) But there would be a much larger influx, because solar panels would be collecting sunlight that would have otherwise missed the earth. > > I now don't understand anymore why does it become warm > > in a greenhouse? > > The glass keeps the cold wind out and is a slight insulator. It only works > if its not really cold, and theirs still a lot of sunlight to warm it up in > the day time. Glass works, because it restricts the heat balance to radiation only by preventing convection (i.e. it keeps the cold wind out.) or conduction (i.e. it is a slight insulator) in that respect, it is just like the vacuum of space, that vacuum prevents convection and conduction, and restricts the heat-balance to radiation terms only. Kevin From popserver Sat Feb 24 06:30:38 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2265" "Sat" "24" "February" "1996" "00:04:26" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "56" "Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id RAA00270 for ; Fri, 23 Feb 1996 17:38:11 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24082 (5.67b/IDA-1.5); Sat, 24 Feb 1996 00:04:26 +0100 Message-Id: <199602232304.AA24082@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Greenhouse Date: Sat, 24 Feb 1996 00:04:26 +0100 >> >You keep assuming greenhouse gasses cause global warming. That is an >> >unproven theory. > >> No, I keep assuming that greenhouse gasses do keep the >> heat in and I've never heard (except from you) that it >> keeps the heat out or has no effect at all. > >Sorry. > >How could it keep Earth heat in without keeping some solar heat out? My error, it keeps MORE in than it keeps out: I think I made a mistake, by using the word reflection, it seems that the heat is absorbed by the atmosphere. This means both solar-heat and soil-heat. Other radiation is going through the atmosphere without much interaction. Of course the atmosphere radiates the heat away until an equilibrium exists. This equilibrium has an higher temperature than it would without greenhouse gasses. Let me quote the following: "The surface of the earth is warmer than it would be in the absence of an atmosphere because it receives energy from two sources: the sun and the atmosphere." >> You are saying that greenhouse gasses don't exist, or in >> other words there are no gasses that have a higher >> reflectivity for IR-light than for visible and UV-light. > >No, I'm saying that introducing IR reflective gas wouldn't nessisarily heat >up a planet that got most of its surface temp from outside sources. Given >that a lot of IR reflective gas has been added to the atmosphere without >changing the temp, and no one has a coherent explanation for how it would >increase the temp, and the whole idea is vigorously debated, I'ld say it >seems like a dud theory. I've mislead you by saying the greenhouse gasses are reflective for IR, I interpreted the word opaque by reflecting. Having read more about the greenhouse effect this slowly became clear to me. I hope you can see, that this difference makes a lot of difference in our theories. >Could we go back to talking about the star ship? Yes, if we have something to talk about. Everyone seems to be awfully quiet lately... To end this discussion properly, I would strongly recommend that you read the "bad greenhouse" page. (I think you didn't do that yet) I (http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html) Timothy P.S. If you read that rather small page, I would really be interested in what you think of it. From popserver Sat Feb 24 06:30:40 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5507" "Sat" "24" "February" "1996" "00:04:17" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "115" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id RAA00338 for ; Fri, 23 Feb 1996 17:39:00 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA24073 (5.67b/IDA-1.5); Sat, 24 Feb 1996 00:04:16 +0100 Message-Id: <199602232304.AA24073@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Sat, 24 Feb 1996 00:04:17 +0100 >> As said before, even if the launcher is 100 metres in >> length it still may be difficult. The best thing we could >> do is search for a big asteroid which has no own-rotation >> and is in a far orbit from it's sun (and thus moves not >> much during a few months). > >Everything in fre space tumbles at various speeds and directions. So I assumed there would at least be one that met our wishes. >Ah, I see your mistake. The angular deflection isn't based on the physical >dimentions of the launcher, but on the accuracy and precision of the lateral >correction trim thrusting, and deviation sensors. Yes, I was already expecting that something could be the case. >You measure the course of the accelerating packet with lasers and use lateral >magnetic or electrostatic fields to adjust the direction. (Its easier if you >do this after it leaves the end of the accelerator.) This way the final aim >presision is not related to the size of the launcher. This assumes you can quite accurately steer a packet, but a packet is build up of a lot of small particles all going their own way (of course mainly forwards). So you may be able to influence the general direction but not the individual directions. I think it is the latter that will create the problem. >> That's like extending a rifle to shoot an big asteroid >> instead of a bullet (that's only 1E10). I'm not pointing >> to the extra energy needed, but just to the fact that >> things cannot be enlarged without changing completely. > >Tru the launcher would be more like an electromag cannon then a partical >accelerator (and I really wish I had some numbers on the power a mag launcher >takes) but that doesn't mean the system would scale up linearly with the size >of the load. You could calculate the least amount of energy very easely if you know the exhaust speed and the amount of mass per second. Indeed it would not have to scale up linearly but it also may be worse, namely scale up quadraticly. It often happens when things are scaled down, they become easier to make. That is why I would expect that scaling them up would make it more difficult. >>>>>Same in the ship. >>>> >>>>No, the ship would have much less resources (ores and >>>>machinery). >>> >>>The ship would have identical machinery (it would have to carry it eiather >>>way), I'm not really sure of the extra ore would make a big difference. >> >>I was assuming they could extend=build new tools when >>they arrived (eg. large, low-tech equipment like >>steel-rollers) > >I was assuming the low tech heavy stuff (like structure) would hold together >longer than the lighter deatiled stuff (like IC chips and life support >systems). I wonder if we could change that: make high-tech stuff hold together longer than low-tech stuf. I imagine that in the futere this may become true (think of nanosystems). But for todays-technology it may be possible too. When a memory chip has one bad bit we throw it away, of course we could make it so that just that bit was never used (or that byte, whatever). That is what we often do with low tech equipment, for example scissors, even if they are blunt we can use them although worse than before. For the structure the same thing applies, it will have some backups before a life threathening situation will occur. The only problem is that higher-tech (not highest-tech) has only few redundancies because that isn't efficient in our society. About highest tech, we won't be using that much, since it is inherently dangerous to use systems that haven't proven their workings enough. >> I think that is because so far no one has been recovered >> after being freezed in, most people think that it is >> impossible to revive a person either because of religious >> and/or technical reasons. >> Of course there may be other methods of hibernation that >> are less drastic, although probably all methods mean that >> people should be in a deep coma. I wonder if the media >> likes the idea of killing people just so far that they >> are continiously on the stairway to heaven. > >Oddly, I think most people assume hibernation is trivial. Lots of animals >hybernate for months at a time and stop their motabalism. People have talked >about puting crews in hybernation for long trips for so long that its taken >for granted by people. Yes, but most people also think that walking without spacesuit on another "green" planet is without dangers. I hope that you are not suggesting that the sci-fi movies determine what the public will find acceptable or not. Are you also thinking that hibernation is more or less trivial? Animals that are hibernating do age too, maybe hibernation even decreases the lifetime. ============================================================================= >> OK, I see that. But is it that difficult to extend the >> equipment from making bolts with a precision of 1/1000 >> mm to making a micro chip? > >Well there is, but more importantly you wouldn't ever make a bolt that >precise for structural or heavy systems use. But it may well be that a lot of parts are used upto their maximum capabilities. Otherwise things may become several times bigger and heavier. Having said this, and remembering an earlier part of this letter I could conclude that the lowtech parts which have a natural redundancy may even be bigger or heavier than high-tech parts that have an enlarged artificial redundancy. ("enlarged artificial" meaning, more refined or more duplicates) Tim From popserver Sat Feb 24 06:30:46 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4192" "Sat" "24" "February" "1996" "00:48:03" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "85" "Re: your mail = Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id RAA00432 for ; Fri, 23 Feb 1996 17:39:57 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA25376 (5.67b/IDA-1.5); Sat, 24 Feb 1996 00:48:02 +0100 Message-Id: <199602232348.AA25376@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse Date: Sat, 24 Feb 1996 00:48:03 +0100 >> No sunlight is hotter in the IR band, and your not talking about the amount >> that gets to the ground, your talking about what hits the top of the >> atmosphere. IR reflective gasses would reflect that back out. Thus lowering >> the solar heat gain. Thus lowering the Earth surface temp during the day. > >It isn't that sunlight is stronger or lower in the IR bands, it's that >earth-light is much much loser in the UV and visible bands. What do you mean by loser? >the gases (or whatever) keeps IR from passing, so both solar IR and >earthly IR are reflected. The UV and Visible portions of the spectrum >usually pass right through and then strike the ground, but the ground >doesn't heat up enough to produce visible or UV radiation, so it's sent >out as IR. The diving force of the greenhouse is not the difference >between earthly IR and Solar IR, it is the difference between solar >Visible and UV and Earthly visible and UV (~0) That is what I thought and it has a certain truth but I think I was wrong using the term reflection, it is better to assume that IR is absorbed on it way through the atmosphere. >> that a lot of IR reflective gas has been added to the atmosphere without >> changing the temp, and no one has a coherent explanation for how it would > >that is not true. the _has_ been a temp rise over the last 90-100 >years. It is small, and it cannot be _proven_ to be caused by the >greenhouse gases, but it has occured. Indeed, NASA is only one experiment. Ground-based weather data show a clear increase. I am interested though why both methods seem to disagree. (CSIRO writes in an article that global temperature did increase the last century, so it is not just a story from the newspapers and environmentalist) >> increase the temp, and the whole idea is vigorously debated, I'ld say it > >Only by those who are afraid to have industrial society collapse around >thier ears if the environmentalists win. The Industrialists are right >about one thing, we can't stop yet. if we quit burning petrochemicals, >we would be starving inside of three months. But the environmentalists >are right about something too, we _will_ one day have to stop burning >oil, because we are going to run out one day. How convenient, whatever we do, we're gonna die anyway ;) >BTW, Space-based solar energy beamed down by microwave will not solve the >greenhouse problem, but will make it worse instead. Energy (microwaves) >would be entering the earth's atmosphere, (we'd choose a particularly >transparent frequency, to avoid losses) and then be consumed by various >items (television, motors, light-bulbs etc) which waste large amounts of >energy as heat. The heat would be held in just as it is now, (when >talking about a planet, radiation is the only means of heat shedding) But >there would be a much larger influx, because solar panels would be >collecting sunlight that would have otherwise missed the earth. I thought of this before and calculated: World energy usage: 10^10 kWh=3.6 10^13 Watt Solar Input at the Earth disc: Pi*(6.378 10^6)^2*1400=1.8 10^17 Watt So Solar radiation is about 5000 times more than current electric power use. (I don't know how much other power, like gass and oil is used) I wonder if this effect is big enough to make a difference, if it does we always could remove some greenhouse gasses or decrease the normal solar input. Besides that, we will move heavy industry to space like Kelly said before. Also appliances will become more efficient than today. >> > I now don't understand anymore why does it become warm >> > in a greenhouse? >> >> The glass keeps the cold wind out and is a slight insulator. It only works >> if its not really cold, and theirs still a lot of sunlight to warm it up in >> the day time. > >Glass works, because it restricts the heat balance to radiation only by >preventing convection (i.e. it keeps the cold wind out.) or conduction >(i.e. it is a slight insulator) in that respect, it is just like the >vacuum of space, that vacuum prevents convection and conduction, and >restricts the heat-balance to radiation terms only. Yeps, I see that now. Timothy From popserver Sat Feb 24 17:57:48 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5183" "Sat" "24" "February" "1996" "02:59:05" "-0600" "Kevin C. Houston" "hous0042@maroon.tc.umn.edu" nil "105" "Re: your mail = Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub1.tc.umn.edu (mhub1.tc.umn.edu [128.101.131.51]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id BAA25618 for ; Sat, 24 Feb 1996 01:00:20 -0800 (PST) Received: from maroon.tc.umn.edu by mhub1.tc.umn.edu; Sat, 24 Feb 96 02:59:06 -0600 Received: by maroon.tc.umn.edu; Sat, 24 Feb 96 02:59:05 -0600 In-Reply-To: <199602232348.AA25376@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse Date: Sat, 24 Feb 1996 02:59:05 -0600 (CST) On Sat, 24 Feb 1996, Timothy van der Linden wrote: > >It isn't that sunlight is stronger or lower in the IR bands, it's that > >earth-light is much much loser in the UV and visible bands. > > What do you mean by loser? Sorry, I meant lower. the s key and the w key are too close on my keyboard :) > >that is not true. the _has_ been a temp rise over the last 90-100 > >years. It is small, and it cannot be _proven_ to be caused by the > >greenhouse gases, but it has occured. > > Indeed, NASA is only one experiment. Ground-based weather data show a clear > increase. I am interested though why both methods seem to disagree. (CSIRO > writes in an article that global temperature did increase the last century, > so it is not just a story from the newspapers and environmentalist) One theory, is that it is due to the "heat island" effect around urban centers. but this does not seem adequate in talking about records gathered in small rural towns (like my home town of Viroqua WI)(5megs of nudity pictures if you can find Viroqua on your local map -- No fair going to the library) The population of Viroqua is something like 3600, and the whole town fits within one square mile. Heat island effect cannot explain the temp rise is such pastoral settings. But, this does not prove the assertion that it is caused by greenhouse gases. > How convenient, whatever we do, we're gonna die anyway ;) No, we will just have to find another source of energy, it will either be fusion or space-based solar About the ship: I have a design outline that I would like everyones comment on: 1) Ship leaves Sol using Maser sail. 2) Ship enters TC using MARS lineac. 3) Exploration of TC and construction of maser array. 4) return module (more on this below) leaves TC using Maser sail. 5) Return Module enters Sol using Maser Sail. The Lineac Core, large tanks, rotating hab sections, exploration equipment, etc. would all remain in TC system. only the return module and the maser sail would go back. This should reduce the return module mass by a factor of 25 (from 2.5 E9 to 1 E8)Kg the return module would be the crews quarters during both acceleration phases, the mass should be about 1 E8 Kg (may be too large) during the trip to TC, the return module would be tucked inside the rotating hab sections. the Rotating sections, then are freed from the design criteria of having to adapt to multiple gravity vectors, the rotating portions are designed to rotate only. This greatly increases the amount of interior space available to the TC explorers while in the target system. imagine a Coca-Cola can with a straw through it along the centerline. This would be like the return module with the lineac core. Then imagine the entire assemblage inside a tin can (like for soup)(there would also be RM tanks, but ignore that for now) At TC, the soda can and the straw would be removed from the soup can. the soup can would be spun for gravity, and the researchers would live on the inside surface. extra mass from TC asteroids could be added to the outside to increase the shielding factor. Since the soup can would be staying behind anyway, it could be designed to be like a colony if necessary. The core would be removed from the Cola can, and the cola can would return to earth at the end of the mission. The maser array could be smaller, and regular shuttle flights between the two systems could easily be established if it was found to be economical. the design of the cola can would be very simple, a cylinder about 150 meters in diameter, as long as you like provided the total mass stays about 1 E8 kg. also the interior 50 meters dia is for the core. Anyone wishing to design living space, here is your target. At the midway point, we coast for a few days (crew time) by firing the lineac at just the right strength to cancel the foreward momentum gained by absorbing the maser beam. while we are in this "free fall" state, the cola can is removed from the soup can, and put back upside down. this is mostly accomplished with winches and motors. once the "flipping" manuever is finished, the lineac engine revs up and we begin decelerating into TC. I just realized the core doesn't have to go through the cola can, but I am too lazy to correct the previous paragraphs. And proper design (with a pivot point halfway up the cola can) would allow the can to flip quite easily. During powered phases of the trip, crew would eat stored rations 10 years of pretty good pre-packed food with 10 years of freeze-dried concentrates in case something goes wrong. During the exploration phase, the rotating RM tanks (now empty) can be used as farm space. Also, the return module can be repaired because nobody is living in it. If some alien bacteria should get loose on the rotating portion of the ship, people can escape to the return module. People can be left behind in the star system if they are infected, without worrying that you are being cruel, because they will have a place to live. I will be putting this on a web page soon, so that you all can see what I am talking about. Kevin Houston From popserver Sat Feb 24 17:59:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2232" "Sat" "24" "February" "1996" "16:11:58" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "56" "Read this" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id HAA05864 for ; Sat, 24 Feb 1996 07:13:12 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA06943 (5.67b/IDA-1.5 for ); Sat, 24 Feb 1996 16:11:58 +0100 Message-Id: <199602241511.AA06943@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Read this Date: Sat, 24 Feb 1996 16:11:58 +0100 Hi all, I found something on a NASA ftp-site: ftp://explorer.arc.nasa.gov/pub/SPACE/FAQ/eder_transport_list The total size is 111 Kb. I added the introduction of this article so that you can see if you already know it or to make you curious.. Canonical List of Space Transport and Engineering Methods Version 0.75 28 Jun 1994 Introduction This document is a list of all known space transport methods and some space engineering methods. It includes only those methods whose underlying physical principles are understood (i.e. no warp drives as in Star Trek). It is the product of a number of years of collecting - and occasionally inventing - them. I am motivated by a desire to see civilization expand into space and my frustration by the slow pace of progress at the current time. Most current space vehicles and projects use techniques that existed in the 1950's and 1960's. Some new ideas were developed as early as 1960, but have not been put into used even today. From the 1970's to today many additional ideas have been generated. Most of these have received scant attention. By disseminating information on these ideas, I hope others will realize the vast untapped potential contained in these ideas. This draft (version 0.75) lists all the concepts I am aware of, with at least a basic description of each. As you can tell by the version number, which is less than one, this is still very much a work in progress. Later versions of this document are intended to flesh out each method with improved descriptions and current references. If you know of a method which is not on this list, I would appreciate being informed of it. If you have references or text descriptions on a concept, they would be appreciated also. Some related information on the basics of space transport, the forces and energies used, and space project engineering are included. Editorial comments and material that needs lots of editing appear in square brackets. The document contains the following sections: Section A: Basics of Space Transport Section B: Propulsive Forces List Section C: Energy Sources List Section D: Propulsion Concepts List Section E: Space Engineering Methods Section F: General References Timothy From popserver Mon Feb 26 04:07:27 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2889" "Sun" "25" "February" "1996" "23:01:38" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "60" "Re: your mail" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05053 for ; Sun, 25 Feb 1996 20:03:44 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id XAA23549; Sun, 25 Feb 1996 23:01:38 -0500 Message-ID: <960225230136_153426059@mail04.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu cc: bmansur@oc.edu, David@interworld.com, jim@bogie2.bio.purdue.edu, lparker@destin.gulfnet.com, rddesign@wolfenet.com, stevev@efn.org, T.L.G.vanderLinden@student.utwente.nl, zkulpa@zmit1.ippt.gov.pl Subject: Re: your mail Date: Sun, 25 Feb 1996 23:01:38 -0500 >> that a lot of IR reflective gas has been added to the atmosphere without >> changing the temp, and no one has a coherent explanation for how it would > that is not true. the _has_ been a temp rise over the last > 90-100 years. It is small, and it cannot be _proven_ to be > caused by the greenhouse gases, but it has occured. Between mid 1800's and mid 1900's the temp droped about 2 degrees F, from mid 1700's to mid 1800's it went up much more than that. (1700's was tail end of the little ice age.) > > --increase the temp, and the whole idea is vigorously > > debated, I'ld say it --- > Only by those who are afraid to have industrial society > collapse around thier ears if the environmentalists win. Hardly. Very little about the climate has any hard strong scientific support. Or even strong data. There is a big debtae over weather the climate is coling, heating, or none of the above. None of the above geting yelled at by camp up and camp down. The only reason global warming gets so much more press is the ecologists are pushing that one. > The Industrialists are right about one thing, we can't stop > yet. if we quit burning petrochemicals, we would be > starving inside of three months. The cities would die of polution and lack of water sooner than that. > But the environmentalists are right about something too, > we _will_ one day have to stop burning oil, because we are > going to run out one day. Not really. Oil geologists figure we have about 200 years worth on earth. If you want to use near eath comet cores you get a few thousand more years worth. Academic thou. The oil industry expects their markets to colapse in the mid 21st century as fussion and usable bateries come on line (there more convenent, and smell better) > BTW, Space-based solar energy beamed down by microwave > will not solve the greenhouse problem, but will make it > worse instead. Energy (microwaves) would be entering > the earth's atmosphere, (we'd choose a particularly > transparent frequency, to avoid losses) and then be > consumed by various items (television, motors, > light-bulbs etc) which waste large amounts of energy > as heat. The heat would be held in just as it is now, > (when talking about a planet, radiation is the only means > of heat shedding) But there would be a much larger > influx, because solar panels would be collecting sunlight > that would have otherwise missed the earth. You of course are ignoring the power plants the microwave plants would replace. Conventional power plants usually generate more heat than electricity. But microwave conversion is highly efficent (90%-99%). So the microwave beem sent down to replace a power plant would eliminate 1-2 times its own power in waste heat from the old power plants. The waste heat from the consumer appliances is of course the same eiather way. Kelly From popserver Mon Feb 26 04:07:29 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3244" "Sun" "25" "February" "1996" "23:01:59" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "79" "Re: Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout06.mail.aol.com (emout06.mail.aol.com [198.81.10.43]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05158 for ; Sun, 25 Feb 1996 20:04:38 -0800 (PST) Received: by emout06.mail.aol.com (8.6.12/8.6.12) id XAA03280; Sun, 25 Feb 1996 23:01:59 -0500 Message-ID: <960225230156_153426319@emout06.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Greenhouse Date: Sun, 25 Feb 1996 23:01:59 -0500 Timothy van der Linden > >> >You keep assuming greenhouse gasses cause global warming. That is an > >> >unproven theory. > > > >> No, I keep assuming that greenhouse gasses do keep the > >> heat in and I've never heard (except from you) that it > >> keeps the heat out or has no effect at all. > > > >Sorry. > > > >How could it keep Earth heat in without keeping some solar heat out? > My error, it keeps MORE in than it keeps out: That would be a neat trick. In the daytime the bulk of energy would be coming from the sun, so it should reflect/reemmit/whatever more of that then from the earth sources. At night of course it would work the other way around. So you'ld expect a cooling effect in the day and warming at night. > I think I made a mistake, by using the word reflection, > it seems that the heat is absorbed by the atmosphere. > This means both solar-heat and soil-heat. Other radiation > is going through the atmosphere without much interaction. Reflection is a bit simplistic, but the general effect is similar. Oh, and most of the spectrum is effected by its passage through the atmosphere. visible light is the least effected. > Let me quote the following: > "The surface of the earth is warmer than it would be in > the absence of an atmosphere because it receives energy > from two sources: the sun and the atmosphere." Obviously simplistic given the diffences between Earth and moon. Lunar temps snap between 200F degrees above zero to 200f degrees below durring the day night cycle, and change rapidly at sunset/sunrise. Its more corect to say the atmosphere (and water) moderates the temperature changes dramatically. Since they act as heat sinks. > >> You are saying that greenhouse gasses don't exist, or in > >> other words there are no gasses that have a higher > >> reflectivity for IR-light than for visible and UV-light. > > > >No, I'm saying that introducing IR reflective gas wouldn't nessisarily heat > >up a planet that got most of its surface temp from outside sources. Given > >that a lot of IR reflective gas has been added to the atmosphere without > >changing the temp, and no one has a coherent explanation for how it would > >increase the temp, and the whole idea is vigorously debated, I'ld say it > >seems like a dud theory. > I've mislead you by saying the greenhouse gasses > are reflective for IR, I interpreted the word opaque by > reflecting. Having read more about the greenhouse effect > this slowly became clear to me. I hope you can see, that > this difference makes a lot of difference in our theories. Not really. I didn't think eiather os us thought it worked like a mirror (thou I suppose we could have phrased things a bit clearer). > >Could we go back to talking about the star ship? > Yes, if we have something to talk about. Everyone seems > to be awfully quiet lately... Thats true. Maybe even we are runing out of starship ideas. > To end this discussion properly, I would strongly > recommend that you read > the "bad greenhouse" page. (I think you didn't do that yet) > I (http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html) Ok, I'll read and comment. I'ld recomend some books, but I've no idea whats avalible in North Europe. Kelly From popserver Mon Feb 26 04:07:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5791" "Sun" "25" "February" "1996" "23:02:06" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "142" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from emout07.mail.aol.com (emout07.mx.aol.com [198.81.11.22]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05215 for ; Sun, 25 Feb 1996 20:05:08 -0800 (PST) Received: by emout07.mail.aol.com (8.6.12/8.6.12) id XAA13916; Sun, 25 Feb 1996 23:02:06 -0500 Message-ID: <960225230204_153426498@emout07.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Sun, 25 Feb 1996 23:02:06 -0500 to: Timothy van der Linden > >Ah, I see your mistake. The angular deflection isn't based on the physical > >dimentions of the launcher, but on the accuracy and precision of the lateral > >correction trim thrusting, and deviation sensors. > Yes, I was already expecting that something could be the case. > >You measure the course of the accelerating packet with lasers and use lateral > >magnetic or electrostatic fields to adjust the direction. (Its easier if you > >do this after it leaves the end of the accelerator.) This way the final aim > >presision is not related to the size of the launcher. > This assumes you can quite accurately steer a packet, > but a packet is build up of a lot of small particles all > going their own way (of course mainly forwards). ---- Who says? A fuel packet could be the size of a fright car of that would help, but I'ld assumed it would be smaller. More like pill to bear can sized. It would almost impossible to spray a charged fog of particals out of a gun and keep them together. Their mutual repulsion would cause them to defuse to much. You'ld have to pack them in mini-containers. I supose you could treat those containers or packets as particals, but I don't think thats what your thinking of. > >-- I really wish I had some numbers on the power a mag > > launcher takes > You could calculate the least amount of energy very easely > if you know the exhaust speed and the amount of mass > per second. If you send the equations along I'll run some numbers through for my summary documents. > >>>>>Same in the ship. > >>>> > >>>>No, the ship would have much less resources (ores and > >>>>machinery). > >>> > >>>The ship would have identical machinery (it would have to carry it eiather > >>>way), I'm not really sure of the extra ore would make a big difference. > >> > >>I was assuming they could extend=build new tools when > >>they arrived (eg. large, low-tech equipment like > >>steel-rollers) > > > >I was assuming the low tech heavy stuff (like structure) would hold together > >longer than the lighter deatiled stuff (like IC chips and life support > >systems). > I wonder if we could change that: make high-tech stuff > hold together longer than low-tech stuf. I imagine that > in the future this may become true (think of nanosystems). > But for todays-technology it may be possible too. When a > memory chip has one bad bit we throw it away, of course > we could make it so that just that bit was never used (or > that byte, whatever). -- You could rig up the systems to degrade in capacity not just fail. But the more detailed the structures (like the inside of Nanos) the more slight defects will disrupt the function of the system. (I'n not optimistic about Nanos longevity in radiation fields.) > -- For the structure the same thing applies, it > will have some backups before a life threathening > situation will occur. They alway design them that way, but for things that need high performance per dry weight (like high speed craft) that gets to be a problem quickly. > The only problem is that higher-tech (not highest-tech) > has only few redundancies because that isn't efficient > in our society. About highest tech, we won't be using > that much, since it is inherently dangerous to use systems > that haven't proven their workings enough. Redundancies start to drastically degrade the performance of some systems (like I.C. chips), and we may (or may not) need all the performance we can get for a starship. > >> I think that is because so far no one has been recovered > >> after being freezed in, most people think that it is > >> impossible to revive a person either because of religious > >> and/or technical reasons. > >> Of course there may be other methods of hibernation that > >> are less drastic, although probably all methods mean that > >> people should be in a deep coma. I wonder if the media > >> likes the idea of killing people just so far that they > >> are continiously on the stairway to heaven. > > > >Oddly, I think most people assume hibernation is trivial. Lots of animals > >hybernate for months at a time and stop their motabalism. People have talked > >about puting crews in hybernation for long trips for so long that its taken > >for granted by people. > Yes, but most people also think that walking without > spacesuit on another "green" planet is without dangers. Agreed. > I hope that you are not suggesting that the sci-fi > movies determine what the public will find acceptable > or not. Unfortunatly it will. SF is as close as most people bother to get to science, and the SF movies and books reflect or display the publics assumptions. An example is the move Blade Runner, which was set in an L.A. slumb of the mid 21st century. The producer filled it with stuff from 1940 detective novels and high tech exotica. Yet everyone assumed it was a serious projection of the future. Even critisizing him for the ending where the characters drove out of L.A. to a green and beutify countryside. Which they thought couldn't exist or people wouldn't live in the slumbs. He pointed out thats how it is now, where an hour or two drive separtes the worst poluted slumbs from the green and sparsly populated countryside. Anyway, in a political arena peoples techno prejidices will effect the projects and the protest to them. Every analysis of nuclear powe shows its not capable of poluting as mouch as the coal plants it would replace. Yet nukes get intense public and governmental polution and safty attention, coal little. > Are you also thinking that hibernation is more or less > trivial? No, just that I beleave the public thinks it is. But in politics reality is unimportant, impressions are everything. Kelly From popserver Mon Feb 26 04:07:34 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["336" "Sun" "25" "February" "1996" "23:02:44" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "15" "Re: Read this" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05217 for ; Sun, 25 Feb 1996 20:05:09 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id XAA24122; Sun, 25 Feb 1996 23:02:44 -0500 Message-ID: <960225230242_153426874@mail04.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Read this Date: Sun, 25 Feb 1996 23:02:44 -0500 > Hi all, > I found something on a NASA ftp-site: > ftp://explorer.arc.nasa.gov/pub/SPACE/FAQ/eder_transport_list > The total size is 111 Kb. I added the introduction of this > article so that you can see if you already know it or to > make you curious.. Oh yeah, The Danny Elder document. I'll have to get a newer copy. Kelly From popserver Mon Feb 26 04:07:35 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1439" "Sun" "25" "February" "1996" "23:02:22" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "36" "Re: your mail = Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail02.mail.aol.com (mail02.mail.aol.com [152.163.172.66]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05233 for ; Sun, 25 Feb 1996 20:05:17 -0800 (PST) Received: by mail02.mail.aol.com (8.6.12/8.6.12) id XAA01896; Sun, 25 Feb 1996 23:02:22 -0500 Message-ID: <960225230221_153426623@mail02.mail.aol.com> From: KellySt@aol.com To: T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse Date: Sun, 25 Feb 1996 23:02:22 -0500 to: Timothy van der Linden > >It isn't that sunlight is stronger or lower in the IR bands, it's that > >earth-light is much much loser in the UV and visible bands. > What do you mean by loser? Sorry, typo. I ment lower. ================ > >> that a lot of IR reflective gas has been added to the atmosphere without > >> changing the temp, and no one has a coherent explanation for how it would > > > >that is not true. the _has_ been a temp rise over the last 90-100 > >years. It is small, and it cannot be _proven_ to be caused by the > >greenhouse gases, but it has occured. > Indeed, NASA is only one experiment. Ground-based > weather data show a clear increase. I am interested > though why both methods seem to disagree. (CSIRO > writes in an article that global temperature did > increase the last century, so it is not just a story > from the newspapers and environmentalist) What isthe CSIRO and how did they get their data. To my knowledge NASA is the only attempt to get global temperature data. Obviously most of the world has no regular temperature data taken even now, and the rest seldom bothers to compensate for the temperature changes at the measuring site due to subburban growth. The best long term (multi century) data is from ecological drift. In the U'S. that shows a gradual (with bumps) cooling over the last 800 years, but of course that neiather here nor there in a green house debate. Kelly From popserver Mon Feb 26 04:07:36 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4588" "Sun" "25" "February" "1996" "23:02:33" "-0500" "KellySt@aol.com" "KellySt@aol.com" nil "127" "Re: your mail = Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: KellySt@aol.com Received: from mail04.mail.aol.com (mail04.mail.aol.com [152.163.172.53]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id UAA05276 for ; Sun, 25 Feb 1996 20:05:56 -0800 (PST) Received: by mail04.mail.aol.com (8.6.12/8.6.12) id XAA23999; Sun, 25 Feb 1996 23:02:33 -0500 Message-ID: <960225230232_153426764@mail04.mail.aol.com> From: KellySt@aol.com To: hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl cc: stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse Date: Sun, 25 Feb 1996 23:02:33 -0500 to: Kevin C Houston > On Sat, 24 Feb 1996, Timothy van der Linden wrote: > > >It isn't that sunlight is stronger or lower in the IR bands, it's that > > >earth-light is much much loser in the UV and visible bands. > > > > What do you mean by loser? > Sorry, I meant lower. the s key and the w key are too > close on my keyboard :) You said that? > > >that is not true. the _has_ been a temp rise over the last 90-100 > > >years. It is small, and it cannot be _proven_ to be caused by the > > >greenhouse gases, but it has occured. > > > > Indeed, NASA is only one experiment. Ground-based weather data show a clear > > increase. I am interested though why both methods seem to disagree. (CSIRO > > writes in an article that global temperature did increase the last century, > > so it is not just a story from the newspapers and environmentalist) > One theory, is that it is due to the "heat island" effect > around urban centers. but this does not seem adequate > in talking about records gathered in small rural towns > (like my home town of Viroqua WI) The population of > Viroqua is something like 3600, and the whole town > fits within one square mile. Heat island effect > cannot explain the temp rise is such pastoral settings. Suppose that would depend on where they put the thermometer? > > How convenient, whatever we do, we're gonna die anyway ;) > No, we will just have to find another source of energy, > it will either be fusion or space-based solar I thought you just argued against space based solar? > About the ship: > I have a design outline that I would like everyones comment on: > 1) Ship leaves Sol using Maser sail. > 2) Ship enters TC using MARS lineac. > 3) Exploration of TC and construction of maser array. > 4) return module (more on this below) leaves TC using Maser sail. > 5) Return Module enters Sol using Maser Sail. Last I heard the numbers showed the lineac core couldn't over power the boost from the micro wave. I.E. no brakes! > The Lineac Core, large tanks, rotating hab sections, > exploration equipment, etc. would all remain in TC > system. only the return module and the maser sail > would go back. This should reduce the return module > mass by a factor of 25 (from 2.5 E9 to 1 E8)Kg You'ld need the hab centrafuge for the living quarters otherwise the crews health would decline. Also the heavy radiation shielding would need to be carried. Why do you assume a factor of 25 weight reduction? You never gave any weight breakdown numbers. > the return module would be the crews quarters during > both acceleration phases, the mass should be about > 1 E8 Kg (may be too large) --- Whats your crew compliment? 100,000 tons does leave a lot of weight for shilding. > --- during the trip to TC, the return module would be > tucked inside the rotating hab sections. the Rotating > sections, then are freed from the design criteria > of having to adapt to multiple gravity vectors, the > rotating portions are designed to rotate only. -- Sounds like you just doubled the size of the habitation zones. One complete set for accel and decel, another for artificial G (centrafuge) operations. > --- This greatly increases the amount of interior > space available to the TC explorers while in the target > system. I don't see how. ---< snip>--- > I will be putting this on a web page soon, so that you > all can see what I am talking about. > Kevin Houston I hope I can get to it over the web. ;) Kelly ----------------------- Headers -------------------------------- >From hous0042@maroon.tc.umn.edu Sat Feb 24 03:59:50 1996 Return-Path: hous0042@maroon.tc.umn.edu Received: from mhub1.tc.umn.edu (mhub1.tc.umn.edu [128.101.131.51]) by emin18.mail.aol.com (8.6.12/8.6.12) with SMTP id DAA23953 for ; Sat, 24 Feb 1996 03:59:49 -0500 Received: from maroon.tc.umn.edu by mhub1.tc.umn.edu; Sat, 24 Feb 96 02:59:06 -0600 Received: by maroon.tc.umn.edu; Sat, 24 Feb 96 02:59:05 -0600 Date: Sat, 24 Feb 1996 02:59:05 -0600 (CST) From: Kevin C Houston To: Timothy van der Linden cc: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse In-Reply-To: <199602232348.AA25376@student.utwente.nl> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From popserver Mon Feb 26 21:47:50 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1512" "Mon" "26" "February" "1996" "08:32:21" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "41" "Re: Fwd: Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id FAA26255 for ; Mon, 26 Feb 1996 05:37:23 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA04864; Mon, 26 Feb 96 08:35:46 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004739; Mon Feb 26 08:33:21 1996 Received: by most (4.1/SMI-4.1) id AA02751; Mon, 26 Feb 96 08:33:16 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma002735; Mon Feb 26 08:32:22 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA21113; Mon, 26 Feb 96 08:32:19 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: T.L.G.vanderLinden@student.utwente.nl, KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, KellySt@aol.com Cc: kgstar@most.fw.hac.com Subject: Re: Fwd: Greenhouse Date: Mon, 26 Feb 1996 08:32:21 -0500 >To end this discussion properly, I would strongly recommend that you read >the "bad greenhouse" page. (I think you didn't do that yet) I >(http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html) > > >Timothy > >P.S. If you read that rather small page, I would really be interested in >what you think of it. Not a bad discussion and debunking of greenhouse effect myths such as "The greenhouse effect is caused when gases in the atmosphere behave as a blanket and trap radiation which is then reradiated to the earth." etc... The author seems about as frustrated with nonscience being bounced around and I am. The statement that "the surface of the earth receives nearly twice as much energy from the atmosphere as it does from the sun." might be a bit confusing. Obviously the atmospher acts as a transport mechanism not an energy source in the true sence (I.E. the atmosphere doesn't generate any energy). But thats a comparativly minor point. I was a little suprized you brought it up, given that this doesn't discus global warming or the so called "greenhouse effect" (i.e. artificial greenhouse gases altering atmospheric IR transmitions) that we've been arguing about. Kelly ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Mon Feb 26 21:48:42 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3165" "Mon" "26" "February" "1996" "09:57:00" "PST" "Brian Mansur" "bmansur@oc.edu" nil "56" "; Mon, 26 Feb 1996 07:58:10 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA15287; Mon, 26 Feb 1996 09:55:58 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <3131F41E@mainpobox.oc.edu>; Mon, 26 Feb 96 09:55:42 PST Message-Id: <3131F41E@mainpobox.oc.edu> Encoding: 56 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: Kelly Starks Cc: David , hous0042 , jim , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: ; Mon, 26 Feb 1996 10:55:00 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA14125; Mon, 26 Feb 1996 12:53:07 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <31321DA2@mainpobox.oc.edu>; Mon, 26 Feb 96 12:52:50 PST Message-Id: <31321DA2@mainpobox.oc.edu> Encoding: 38 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: David Cc: hous0042 , jim , Kelly Starks , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: My Two Bits Ain't Worth 1E-15cents Date: Mon, 26 Feb 96 12:54:00 PST Okay, I just realized something about my two bits worth. They ain't worth squat. I ran the numbers for 11GW/ton/s on my portable RPB decelerator idea and came back to the same problem that Kelly has with his Explorer design. We need too stinkin much power. Assuming 11GW/ton/s to accelerate a measly .036 g and using a De + 3He reaction that yields 3.606E14 Watts/kg and applying that over the time it takes to accelerate to 1/3c at .036 g the numbers got supremely ugly in terms of fusion fuel weight. Back to the drawing board. Perhaps the launcher idea could still work with the Explorer design. What we have to do turn the Asimov into its own fuel launcher. Have the ship rail gun launch most to all of the ship's reaction mass behind it. The particles will have to be at least fast enough to cover a .25 ly track in the time it takes to cruise to Tau Ceti (if we could keep the track together over that amount of time and distance, would it be easier to launch the track from Earth?). As the Asimov begins its deceleration phase, the relatively faster moving reaction mass track slams back into the ship. We ionize the RM and run it through the accelerator for thrust just as if it were interstellar medium. A downside to this idea is the drag caused by hitting the really fast particles at the end of the deceleration run. Also there are going to be serious power cost to launch the track. Kevin's 11.5 ly long power cord is looking better all the time. Since we'll have to carry so much reaction mass for the launch track, I suggest we use the E18W we have planned to mag-sail launch the ship. So I guess we launch the track via the ion accelerator using it as a rail gun if that is possible. Someone else had better run the numbers on the drag and power needs. That is if anyone thinks this has a chance of working. If not, please show me the error of my ways. From popserver Mon Feb 26 21:49:31 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3342" "Mon" "26" "February" "1996" "13:03:00" "PST" "Brian Mansur" "bmansur@oc.edu" nil "75" "My Two Bits Ain't Worth 1E-15 (Take 2)" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: bmansur@oc.edu Received: from einstein.oc.edu (DNS2.OC.EDU [205.143.216.15]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id LAA20008 for ; Mon, 26 Feb 1996 11:04:45 -0800 (PST) Received: from mainpobox.oc.edu by einstein.oc.edu; (5.65v3.2/1.1.8.2/16Oct95-0320PM) id AA17417; Mon, 26 Feb 1996 13:01:50 -0600 Received: by mainpobox.oc.edu with Microsoft Mail id <31321FAD@mainpobox.oc.edu>; Mon, 26 Feb 96 13:01:33 PST Message-Id: <31321FAD@mainpobox.oc.edu> Encoding: 76 TEXT X-Mailer: Microsoft Mail V3.0 From: Brian Mansur To: David Cc: hous0042 , jim , Kelly Starks , rddesign , stevev , "T.L.G.vanderLinden" , zkulpa Subject: My Two Bits Ain't Worth 1E-15 (Take 2) Date: Mon, 26 Feb 96 13:03:00 PST Okay, I just realized something about my two bits worth. They ain't worth squat. I ran the numbers for 11GW/ton/s on my portable RPB decelerator idea and came back to the same problem that Kelly has with his Explorer design. We need too stinkin much power. Assuming 11GW/ton/s to accelerate a measly .036 g and using a De + 3He reaction that yields 3.606E14 Watts/kg and applying that over the time it takes to accelerate to 1/3c at .036 g the numbers got supremely ugly in terms of fusion fuel weight. Back to the drawing board. Perhaps the launcher idea could still work with the Explorer design. What we have to do turn the Asimov into its own fuel launcher. Have the ship rail gun launch most to all of the ship's reaction mass behind it. The particles will have to be at least fast enough to cover a .25 ly track in the time it takes to cruise to Tau Ceti. I wonder: If we could keep the track together over that amount of time and distance, would it be easier to launch the track from Earth? Would the stablizing system that Kevin told us about help? I noticed this discussion but I don't know if it answers my question: to: Timothy van der Linden > >Ah, I see your mistake. The angular deflection isn't based on the physical > >dimentions of the launcher, but on the accuracy and precision of the lateral > >correction trim thrusting, and deviation sensors. > Yes, I was already expecting that something could be the case. > >You measure the course of the accelerating packet with lasers and use lateral > >magnetic or electrostatic fields to adjust the direction. (Its easier if you > >do this after it leaves the end of the accelerator.) This way the final aim > >presision is not related to the size of the launcher. > This assumes you can quite accurately steer a packet, > but a packet is build up of a lot of small particles all > going their own way (of course mainly forwards). ---- Who says? A fuel packet could be the size of a fright car of that would help, but I'ld assumed it would be smaller. More like pill to bear can sized. It would almost impossible to spray a charged fog of particals out of a gun and keep them together. Their mutual repulsion would cause them to defuse to much. You'ld have to pack them in mini-containers. I supose you could treat those containers or packets as particals, but I don't think thats what your thinking of. So is the answer yes or no. As the Asimov begins its deceleration phase, the relatively faster moving reaction mass track slams back into the ship. We ionize the RM and run it through the accelerator for thrust just as if it were interstellar medium. A downside to this idea is the drag caused by hitting the really fast particles at the end of the deceleration run. Also there are going to be serious power cost to launch the track. Kevin's 11.5 ly long power cord is looking better all the time. Since we'll have to carry so much reaction mass for the launch track, I suggest we use the E18W we have planned to mag-sail launch the ship. So I guess we launch the track via the ion accelerator using it as a rail gun if that is possible. Someone else had better run the numbers on the drag and power needs. That is if anyone thinks this has a chance of working. If not, please show me the error of my ways. From popserver Tue Feb 27 07:31:07 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2595" "Tue" "27" "February" "1996" "07:20:22" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "62" "Re: Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id WAA18107 for ; Mon, 26 Feb 1996 22:21:39 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13800 (5.67b/IDA-1.5 for ); Tue, 27 Feb 1996 07:20:10 +0100 Message-Id: <199602270620.AA13800@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Greenhouse Date: Tue, 27 Feb 1996 07:20:22 +0100 To Kelly >>>How could it keep Earth heat in without keeping some solar heat out? >>My error, it keeps MORE in than it keeps out: > >That would be a neat trick. In the daytime the bulk of energy would be >coming from the sun, so it should reflect/reemmit/whatever more of that then >from the earth sources. At night of course it would work the other way >around. So you'ld expect a cooling effect in the day and warming at night. I think the problem is that we cannot compare radiation temperature with ambient temperature so easely. If you lay a black piece of paper on the ground at a calm hot summer day, it will become very hot, my guess is that it will be about as hot as a similar paper on the moon. >> I think I made a mistake, by using the word reflection, >> it seems that the heat is absorbed by the atmosphere. >> This means both solar-heat and soil-heat. Other radiation >> is going through the atmosphere without much interaction. > >Reflection is a bit simplistic, but the general effect is similar. No, absorbtion means the atmosphere can get warmer, while in the case of reflection it gets no chance to do that. >Oh, and most of the spectrum is effected by its passage through the >atmosphere. visible light is the least effected. Yes, I should have said has less interaction than IR. >> Let me quote the following: >> "The surface of the earth is warmer than it would be in >> the absence of an atmosphere because it receives energy >> from two sources: the sun and the atmosphere." > >Obviously simplistic given the diffences between Earth and moon. Lunar temps >snap between 200F degrees above zero to 200f degrees below durring the day >night cycle, and change rapidly at sunset/sunrise. Its more corect to say >the atmosphere (and water) moderates the temperature changes dramatically. > Since they act as heat sinks. See also above about comparing radiation temps with abient temps. Besides that I assume that the mean temperature of the Earth is about 30 degrees higher than the temps on the Moon. >> To end this discussion properly, I would strongly >> recommend that you read >> the "bad greenhouse" page. (I think you didn't do that yet) >> I (http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html) > >Ok, I'll read and comment. I'ld recomend some books, but I've no idea whats >avalible in North Europe. You can check what is available in my library :) telnet://utlbs3.civ.utwente.nl:23 At least I think it is a non-local connection. Just type "PCEL" or some of the other passwords that are given. Don't reserve books in my name! :) Timothy From popserver Tue Feb 27 07:31:09 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["4555" "Tue" "27" "February" "1996" "07:20:28" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "91" "Re: Re: Summary A" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id WAA18111 for ; Mon, 26 Feb 1996 22:21:42 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13803 (5.67b/IDA-1.5 for ); Tue, 27 Feb 1996 07:20:30 +0100 Message-Id: <199602270620.AA13803@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Re: Summary A Date: Tue, 27 Feb 1996 07:20:28 +0100 To Kelly, >> This assumes you can quite accurately steer a packet, >> but a packet is build up of a lot of small particles all >> going their own way (of course mainly forwards). ---- > >Who says? A fuel packet could be the size of a fright car of that would >help, but I'ld assumed it would be smaller. More like pill to bear can >sized. It would almost impossible to spray a charged fog of particals out of >a gun and keep them together. Their mutual repulsion would cause them to >defuse to much. You'ld have to pack them in mini-containers. I supose you >could treat those containers or packets as particals, but I don't think thats >what your thinking of. Yes, you are right, lets assume packets of 1 kg. Can we accelerate them up to 1E8 m/sec in an accelerator of a few hundreds of metres? I guess, I'm a little overwhelmed by the amount of energy again, but forgetting that, are you planning to use magnetic or charged acceleration? Let do a quick calculation about the acceleration needed: v=x*t a=v*t --> a=v^2/x = 1E16/100 = 1E14 m/s^2 >>>I really wish I had some numbers on the power a mag >>>launcher takes >>You could calculate the least amount of energy very easely >>if you know the exhaust speed and the amount of mass >>per second. >If you send the equations along I'll run some numbers through for my summary >documents. Non-relativistic: Power needed = 0.5 M Vexh^2 Watts M=Mass per second Vexh=exhaus velocity (I'm sorry that it is so simple) >You could rig up the systems to degrade in capacity not just fail. But the >more detailed the structures (like the inside of Nanos) the more slight >defects will disrupt the function of the system. (I'n not optimistic about >Nanos longevity in radiation fields.) What I was hoping is that the quantity could overcome the quality: A lot of nanos could undo the work of a few broken-nanos. Untill the amount get 75-25 still a lot of work can be done. Of course this doesn't rule out the statistical breakdown after a longer period. But only the few extremeties, like the 1:1000 chance of not working directly after manufacturing. I'm quite sure that if we made chips today with size as 10 years ago, we could make them much more robust. OK, all in all, redundancy only works to reduce the number of incidences, but not the total "decay". But the number of incidences may be quite high without redundancies. >> The only problem is that higher-tech (not highest-tech) >> has only few redundancies because that isn't efficient >> in our society. About highest tech, we won't be using >> that much, since it is inherently dangerous to use systems >> that haven't proven their workings enough. > >Redundancies start to drastically degrade the performance of some systems >(like I.C. chips), and we may (or may not) need all the performance we can >get for a starship. Maybe this is something that we did not dig out enough, we all assumed that the engine designs we came up with would work without much problems for most of the time they were needed. But is it really that easy? I wouldn't like to have two enormous engines and one of them suddenly(?) stops working. In the best case we could turn of the other within time. Worst case, the starship would start to rotate an be ripped apart by all the abnormal g-forces. Besides this, can we savely have an engine shutdown for say a week. I can imagine that for beamed energy this may be a problem. (eg. Non matching speeds of beamed matter). So how much backup do we need, does it mean that the whole ship gets twice as big? >Anyway, in a political arena peoples techno prejidices will effect the >projects and the protest to them. Every analysis of nuclear powe shows its >not capable of poluting as mouch as the coal plants it would replace. Yet >nukes get intense public and governmental polution and safty attention, coal >little. Yes, it's sad, however a single mayor error in a nuclear plant can make a whole country (like the Netherlands) inhabitable for a long time. Anyway lets hope fission or renewable energy will soon replace most of them. >> Are you also thinking that hibernation is more or less >> trivial? > >No, just that I beleave the public thinks it is. But in politics reality is >unimportant, impressions are everything. Indeed, maybe it is time to start a (yet another) new science fiction series to promote our ideas and collect money by selling T-shirts, computergames and stocks for our company to be (Live internet discussions and camera shots). (I'm not really kidding...) Timothy From popserver Tue Feb 27 07:31:12 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1154" "Tue" "27" "February" "1996" "07:20:34" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "22" "Re: your mail = Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id WAA18117 for ; Mon, 26 Feb 1996 22:21:47 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13806 (5.67b/IDA-1.5 for ); Tue, 27 Feb 1996 07:20:35 +0100 Message-Id: <199602270620.AA13806@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: your mail = Greenhouse Date: Tue, 27 Feb 1996 07:20:34 +0100 >> Indeed, NASA is only one experiment. Ground-based >> weather data show a clear increase. I am interested >> though why both methods seem to disagree. (CSIRO >> writes in an article that global temperature did >> increase the last century, so it is not just a story >> from the newspapers and environmentalist) > >What isthe CSIRO and how did they get their data. To my knowledge NASA is >the only attempt to get global temperature data. Obviously most of the world >has no regular temperature data taken even now, and the rest seldom bothers >to compensate for the temperature changes at the measuring site due to >subburban growth. The best long term (multi century) data is from ecological >drift. In the U'S. that shows a gradual (with bumps) cooling over the last >800 years, but of course that neiather here nor there in a green house >debate. I hope I had the letters right, as far as I know it is the main Australian scientific organization. The Australians are concerned a lot about the ozon hole (they are the ones that are most fulnarable) I assume this interest makes them also a bit more aware about the greenhouse effect. Timothy From popserver Tue Feb 27 07:31:14 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1351" "Tue" "27" "February" "1996" "07:20:40" "+0100" "Timothy van der Linden" "T.L.G.vanderLinden@student.utwente.nl" nil "34" "Re: Fwd: Greenhouse" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: T.L.G.vanderLinden@student.utwente.nl Received: from student.utwente.nl (driene.student.utwente.nl [130.89.220.2]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id WAA18132 for ; Mon, 26 Feb 1996 22:21:53 -0800 (PST) Received: from slp10048.slip.utwente.nl by student.utwente.nl with SMTP id AA13813 (5.67b/IDA-1.5 for ); Tue, 27 Feb 1996 07:20:42 +0100 Message-Id: <199602270620.AA13813@student.utwente.nl> X-Sender: S9421793@mail.student.utwente.nl X-Mailer: Windows Eudora Version 1.4.3b4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden) To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu, lparker@destin.gulfnet.com Subject: Re: Fwd: Greenhouse Date: Tue, 27 Feb 1996 07:20:40 +0100 Kelly wrote: >>P.S. If you read that rather small page, I would really be interested in >>what you think of it. > >Not a bad discussion and debunking of greenhouse effect myths such as "The >greenhouse effect is caused when gases in the atmosphere behave as a >blanket and trap radiation which is then reradiated to the earth." etc... >The author seems about as frustrated with nonscience being bounced around >and I am. > >The statement that "the surface of the earth receives nearly twice as much >energy from the atmosphere as it does from the sun." might be a bit >confusing. Obviously the atmospher acts as a transport mechanism not an >energy source in the true sence (I.E. the atmosphere doesn't generate any >energy). But thats a comparativly minor point. Yes, I see what you mean. >I was a little suprized you brought it up, given that this doesn't discus >global warming or the so called "greenhouse effect" (i.e. artificial >greenhouse gases altering atmospheric IR transmitions) that we've been >arguing about. Yes, I also read an other page, that was quite large (that one of the CSIRO) Greenhouse basics: http://www.erin.gov.au/portfolio/esd/climate/grenbasi.html I referred ro "Bad Greenhouse" because it made so clear what the main effects were and because it compared a normal greenhouse with the greenhouse effect. Timothy From popserver Tue Feb 27 20:29:39 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["9752" "Tue" "27" "February" "1996" "13:21:54" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "188" "Draft text Externally fueled Fusion drive" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id KAA25157 for ; Tue, 27 Feb 1996 10:24:26 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA02896; Tue, 27 Feb 96 13:23:17 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI002831; Tue Feb 27 13:22:30 1996 Received: by most (4.1/SMI-4.1) id AA09772; Tue, 27 Feb 96 13:22:26 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma009766; Tue Feb 27 13:21:56 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA02210; Tue, 27 Feb 96 13:21:52 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, kgstar@most.fw.hac.com Subject: Draft text Externally fueled Fusion drive Date: Tue, 27 Feb 1996 13:21:54 -0500 Heres some more text to look over. Attack at will. This is what I consider the baseline drive system for my Explorer class design. Kelly Oh, if anyone wants. I can send set of the graphics and HTML files for this and the others. Let me know. ----------------------------------------------------------------------- Primary Drive System: Externally Fueled Fusion Rocket Out of the likely ashes of my Multi-cycle Ram Augmented Interstellar Ramjet (RAIR) drive, I kept one solid piece. The idea of launching fuel to the ship from a fixed launcher in Sol (our home starsystem). The fuel/reaction mass mixtures could be launched as anything from aspirin sized pellets, to truck sized expendable mini-tankers. The former could be scooped up and fused as is, the later could could be docked and off-loaded. I'm not going to go into a detailed analysis of the pros and cons of the different systems, but their are a lot of pros and cons for each. A stream of pellets would be easier to launch and offer less impact danger to the ship. But the pellets would be harder to keep together at a distance from the launcher, and harder for the ship to recover. The ship would need a ramscoop to scoop up its fuel, and when the packets drifted to far to the sides, the ship couldn't pick them up. Mini-tankers on the other hand could use onboard rockets to maneuver to meet the ship. Possibly the ship could beam power to them (via lasers or microwaves) that could be used to drive the tankers attitude rockets, and order it to maneuver in front of the ship for pick up. Or a system like passive laser launchers could be used. These would just require the tanker to have a large block of reaction mass on its backside. The ship could boost, and steer the tankers remotely using lasers. Without any equipment on the tankers. Either way the ship could catch fuel tankers that had drifted thousands, possibly tens of thousands of miles off to the side of the ships flight path. Far more then possible with scoop system. Either way an externally feed system would mean that, the ship wouldn't need to carry the tremendous tonnage of fuel and reaction mass it would need for the flight. Launched fuel and reaction would only be carried by the ship from the time it entered the holding tanks, to the time it was burned. How this would work in each phase of the flight is described below Accelerating out of Sol, our star system. The ship would be heavy. Not only with the weight of its own systems and structure, but food and equipment for the mission, exploration equipment, the crew and their homes; and weighing dozens of times all the rest combined, deceleration fuel (See fusion rocket mass tables). The ships final cruse speed will be limited to the maximum speed it can decelerate from with the amount of fuel it can carry. Given the years of flight time involved, every effort will be made to load the ship with fuel. Pulling out of Our star system, Sol, the ship will accelerate at one ship G, accelerating 10 meters per second, per second. A orbiting launcher will launch the fuel and extra reaction mass the ships motors will need. The ship will be continuously picking up these fuel packets, and feeding their contents into the fusion motors. This will continue until the ship reaches the maximum speed it can slow down from. If the orbiting launcher can still get fuel close enough to the ship for it to pick up, extra fuel can be set out to increase the breaking supply. Possibly allowing the ship to accelerate a little more, giving extra speed for the long flight. Because of the deceleration fuel limitation, it is unlikely that the ship can get to more than a quarter or a third of the speed of light. But that's still a 100,000 kilometers per second. The ship will need to protect itself against impacts. One of the simplest ideas is to push several miles of charged dust ahead of the ship. Ramming a cloud of charged iron dust at a 360,000,000 kilometers per hours will turn most anything into ionized plasma. Which can be shoved ahead of the ship, or off to the sides, by the charges dust cloud handler. Effectively most anything you run into at speed will become more shielding dust. Decelerating into the target star system. Now for the bad news - you have to slow down. We can't pre-load a deceleration course track into the target star with fuel across interstellar distances. So your stuck with the fuel you brought along. Unless we can come up with a neat magnetic trick to brake the ship in empty space (sorry no luck), its fire up the reactors and put things into reverse. Cruising around the target star system At low speed interplanetary runs, the drive works like a conventional fusion rocket burning stored fuel and reaction mass. But the engines that could get us across interstellar space only with difficulty. Can now make this huge ship commute around the confines of a starsystem with ease. A ten hour burn of the main engines will would get you from earth to Jupiter in about a month, or Mars in a week. A two day burn would get you to Jupiter in less than a week. Under four days of constant burn will get you to Mars. About a week of constant burn will get you to Jupiter. Once in system the main ship will be shuttling surface teams, support ships, and equipment around the star system. It size and speed will allow it to drag around tremendous loads of equipment or raw material. It could haul ore in to a construction site for a space colony. Or to a fuel ore processing facility. It will be carrying all the exploration equipment and personnel to anywhere of interest in the starsystem. Accelerating out of the system to go home. As the exploration phase comes to an end the support crew will be processing the tremendous tonnage of fuel ore necessary to refuel the ship for the boost to home. This fuel could be carried on the ship. All those fuel tanks you emptied decelerating into the starsystem could be filled to accelerate you back to home. Or (possibly) the crew could construct a fuel launcher like the one the ship used to leave home. If an automated fuel launcher could be constructed in the target starsystem, and the one near earth relied upon for braking fuel, the ship could launch with her fuel tanks nearly empty. Without the massive load of fuel and exploration equipment the ship could weight a hundredth of its loaded weight when it left Sol. This would allow it to boost faster and to higher speeds, even if the local fuel launcher could only launch a tiny fraction of the fuel the Sol launcher could, even if most of the drive reactors and motors were disabled. Potentially giving this missions crew a much shorter flight home, and allowing future missions into this star system a much shorter round trip. An automated fuel launcher maybe to complicated to big for the crew to construct. But if enough construction gear can be brought along (or some ultra tech like self replicating machines is assumed), this would greatly expand the amount of flights and exploration we could do to this star system. Decelerating into of Sol, our star system. Since the ship can assume that the orbiting fuel launcher in Sol will be turned on to help it slow down. The ship wouldn't need to be heavily loaded down with deceleration fuel. By this point in the mission the ship will be comparatively light. Its fuel tanks empty. Most of the food and consumables consumed. Probably most of the exploration gear left behind. The ship will be coming home needing fuel. Or will it? The ships cruise speed will be a fraction of the speed of light, and it will be flying straight toward the fuel launcher. Obviously a nice neat docking with the incoming fuel packets is out of the question. You could of course use the lasers to steer a mini-tanker in front of the ship and then explode the tanker. The contents will slam into the ships forward dust shield and be heated to plasma. That plasma could be scooped up and channeled into reactors to power the reverse engines. Or Is that necessary? Whatever blasts through the dust shield is going to be hot! The forward electromagnetic barriers that shove the dust ahead of the ship are going to be ramming into, pushing forward, a plasma ball an eight of a mile in diameter and length unknown) ahead of the ship. If their is any fusion fuel in the mess, its probably going to be fusing out ahead of the ship. Effectively the front of the ship will be an open fusion motor. If the launcher isn't firing fuel. Whatever it is launching is still going to be a hellish fireball ahead of the ship. Effectively the ship will be breaking against this artificially induced drag source. You wouldn't even need to run the reactors to keep the electromagnetic nose shield charged. Ducting a little of the plasma through a central core will allow you to use the core as a generator. Converting the energy of the high speed plasma into electricity. Or more correctly converting the ships kinetic energy past the plasma stream into electricity. If you want to get tricky a magnetic 'wiggler' in the plasma stream could be used to lase it. The forward blast from a plasma laser charged by the kinetic energy of a few hundred thousand tons of charging starship should clear anything out of your path. It certainly will show everyone the explorers have returned home. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Tue Feb 27 20:29:49 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3862" "Tue" "27" "February" "1996" "13:34:34" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "74" "Food Mass numbers text" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id KAA27203 for ; Tue, 27 Feb 1996 10:44:27 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA03715; Tue, 27 Feb 96 13:36:23 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI003622; Tue Feb 27 13:34:59 1996 Received: by most (4.1/SMI-4.1) id AA09982; Tue, 27 Feb 96 13:34:56 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma009977; Tue Feb 27 13:34:36 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA04081; Tue, 27 Feb 96 13:34:32 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, kgstar@most.fw.hac.com Subject: Food Mass numbers text Date: Tue, 27 Feb 1996 13:34:34 -0500 Heres some more text to look over. Attack at will. This is what I consider the baseline drive system for my Explorer class design. Kelly Oh, if anyone wants. I can send set of the graphics and HTML files for this and the others. Let me know. ----------------------------------------------------------------------- Food Mass Numbers Normally people assume that food supplies in space will need to come from onboard farms, or some other intricate recycling system. This may be an unjustified assumption. The farms discussed in the "Space Settlements: A design study" (the book I reference frequently, and STRONGLY recommend) lists the farm mass per person at about 36 tons of which 22 tons is soil. The farm includes everything from farm animals to fish, and all normal grains and vegetables. The idea was to make it capable of providing all normal food needed for a standard North American diet for a population of 10,000. Said diet according to their numbers weighed about 1.67 tons per-person per year. They also assumed that with intensive care this farm could produce twice the yield of the best farms on earth. Now we found that rations for field troops or explorers weighed about 2.2 kilos per day (.8 tons per year) and dehydrated could be a lot less. But over all; 36 tons per person is about 21 years of food mass at their 1.67 tons per year, or 45 food years at our .8 tons per year. I'm not even going to bother with freeze dried numbers. We won't want to be out that long! Even if you assume no soil. The mass is still 14 tons per person. Which comes to 8.38 year of 1.67 tons per year food years, or 17.5 years at our ..8 tons per year. Then I realized that the farm design required doubling the internal volume of the habitation centrifuge. Which would add another 20 to 230 tons per person! (the latter if you shielded the farm centrifuge from ambient radiation.) Any way I ran it, the mass for a transportable, self sustaining farm, wound up greater than the stored food mass for the duration of our projected missions. Given that the stored mass would decline as the mission goes on (a good thing for the return flight), stored food would be simpler and more reliable than trying to maintain a running farm during a mission, and the farm would almost double the size of the full g gravitation sections needed in the ship. I decided to dump the idea and assume ultra frozen and dried foods stored in the zero g section of the ship. We could have a couple gardens for fun and fresh Veggies, but I'd assume they were just a couple plants in the corner of peoples apartments. You might do an analysis to see if hydroponics for the veggies would weigh less than storing frozen veggies. I.E. we store the meat, flour, rice, milk, ect.., but grow the fruits and vegetables. But for my porpoises I assumed the mass numbers wouldn't show an advantage. Oh, while on the topic of Mass. The drive system people seem to be going through hoops to build a huge, high efficiency (relativistic exhaust) engine to keep the necessary reaction mass amounts down to grams per day. I would suggest that if we aren't going to recycle our -- ah-- food by products. The crew will be providing a few tons of usable mass per day. Dehydrate, incinerate to plasma or ionize, and pump it into the accelerator. With an electromagnetic accelerator (as apposed to a thermal rocket) the type of mass used is unimportant, and for ship design purposes using the same stored mass to feed the crew and drive system is very elegant and efficient. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Tue Feb 27 20:29:51 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["10028" "Tue" "27" "February" "1996" "13:38:59" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "211" "Old RAIR drive system" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id KAA27531 for ; Tue, 27 Feb 1996 10:47:31 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA04136; Tue, 27 Feb 96 13:44:15 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI004003; Tue Feb 27 13:42:17 1996 Received: by most (4.1/SMI-4.1) id AA10213; Tue, 27 Feb 96 13:42:14 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma010095; Tue Feb 27 13:39:01 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA04679; Tue, 27 Feb 96 13:38:58 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, kgstar@most.fw.hac.com Subject: Old RAIR drive system Date: Tue, 27 Feb 1996 13:38:59 -0500 Heres some more text to look over. Attack at will. This was what I consider the baseline drive system for my Explorer class design. Untill I figured out it probably wouldn't work. Kelly ----------------------------------------------------------------------- multi-cycle Ram Augmented Interstellar Ramjet (RAIR) Spring 1995 A drive idea I came up with, and used as the assumed system for this ship, is A multi-cycle Ram Augmented Interstellar Ramjet (RAIR). It would scoop up reaction mass from interstellar space like a pure ram scoop, but it would only use it as reaction mass, not fuel. But the scoop system could simultaneously scoop up fuel thrown ahead of the ship by a fixed launcher back in our solar system. The system is basically an electromagnetic accelerator running through the core of the ship, powered by onboard fusion reactors. The accelerator could accelerate scooped-up interstellar matter (or ram flow), or reaction mass carried in the ship. Again, this kind of system is different from a true Bussard ramscoop drive in that the ram flow is not fused for power. Indeed, it normally isn't even slowed down. The engine functions in various ways at various speeds. Interplanetary Flight Mode (Plasma Drive) At low speed interplanetary runs, the drive works like a conventional ion rocket or mass driver. Stored reaction mass is feed into the electromagnetic or electro static accelerator core. Unlike normal thermal rockets, an ion thruster works more efficiently with heavy atom ions. So I'll assume we are storing iron for reaction mass. Specific impulse varies depending on the exhaust velocity of the expended mass. Acceleration To InterStellar Cruise For acceleration out of the Sol system the ship will deploy its ramscoop and switch to the externally fueled RAIR configuration I came up with. As mentioned above, a normal RAIR doesn't try to fuse anything it scoops up. It just ionizes it (with a laser), scoops it (interstellar gas and dust) up, and accelerates it as reaction mass in a linear accelerator. This gets around the Bussard Ramscoop problem of getting more drag trying to fuse the interstellar matter than you get back as thrust (and the fact we can't find enough in interstellar space to run it), and could put any interstellar matter to best use. But you still need a lot of fuel to power the accelerator. The idea I came up with to get around this fuel problem is to launch the fuel ahead of the ship with orbital accelerators (thus the externally fueled part of the name). The accelerators back home throw out HUGE quantities of frozen pellets of whatever fusion fuel is selected, in the path of the ship (called the acceleration track). The fuel is launched at measured and timed speeds, so that the ship will encounter a fairly steady stream of fuel during its run down the fuel loaded acceleration track. As the ship accelerates, it catches up with fuel going at increasing speeds, but always at speeds slightly slower than the ship itself. This way the ship doesn't have the drag a true ramscoop would have accelerating interstellar fuel that is going much slower than the ship is. All incoming mass is hit with a short length of electric or magnetic forward thrust once it enters the ship. The fuel, being close to the speed of the ship, will be accelerated to the ship's speed and can be transferred to temporary fuel tanks. The interstellar mass, being at a far different speed and direction than the ship, will blow past the magnetic catcher into the main thrust accelerator (powered by the soon to be burned fuel). If you can load a 1/4th light year track with enough fuel to keep the ship accelerating at 1g, the ship will (after 6 months) exit the track at half of light speed (0.5c). If a pure ramscoop can work at any speed, it should work at this speed. But assuming we can't make a pure ramscoop work (as we are) the ship can accelerate the external mass using power supplied by fuel stored on-board, or the ship can coast to the target star. Assuming Alpha Centauri, in the later case it will coast for about eight years. Deceleration and system entry Now for the bad news - you have to slow down. We can't pre-load the deceleration course track with fuel at the target star because it would be virtually impossible across interstellar distances. Carrying enough fuel / reaction-mass to decelerate at the target star would be prohibitive at any great speed. Fortunately, there may be a solution to this dilemma, from a rather unlikely source. G. E. Seger found a 1978 paper by Heppenheimer on ramjets. Heppenheimer applies radiative gas dynamics to ramjet design and eventually proves that radiative losses (via bremsstrahlung and other similar synchrotron radiation-type mechanisms) from attempting to compress the ram flow for a fusion burn would exceed the fusion energy generated by nine orders of magnitude (IE. about a billion times!). By conservation of energy laws, those energy losses have to be made up from somewhere. The only suitable source around is the starships kinetic energy. So a bad Ram Scoop drive makes a great starship brake. By reconfiguring the RAIR fields to attempt to compress and initiate a fusion burn in the ram flow, the starship instead will be generating a tremendous braking force. The resulting plasma (fused or unfused) can then be run through the main accelerator (rerigged as a generator) and used to generate electricity. Which in itself will cause further drag on the ship. Or, if we power the accelerator in reverse and force the pre-fusion plasma back down the throat of the oncoming ram flow, it will serve as a reversed plasma drive. Insystem shuttling Once in the target star system the ship once again becomes a fast Plasma or Ion drive ship. Its first target will no doubt be the outer star system and a asteroid, moon, or comet rich in fuel and reaction mass. After that it can shuttle back and forth in the star system. Though it will be crawling compared to its high speed interstellar run. Its 1g thrust capacity will allow it to rapidly reach any part of the star system. Accelerating out of the target system If we drop most of the exploration equipment and eat the consumables, the ship should be a lot lighter on the return leg. This should make it easier for it to accelerate without an externally loaded acceleration fuel track. The ship may be able to load itself with massive amounts of extra fuel, burning all the fuel, even most of the fuel that would have gone into decelerating the ship, into accelerating it. But this must be worked out in more detail. (See Internally fueled fusion rockets.) Otherwise, the crew could be forced to construct an automated fuel launcher system at the target star. This seems a clumsy and unreliable method, but I haven't thought of another. Reentry to the home starsystem The ship can not only use its ramscoop brake to slow down, it can use the Externally fueled RAIR scooping up fuel from a deceleration track at the edge of Sol, preloaded with fuel. This works like when we first left the Sol system, except that the fuel is blasting right down the throat of the ship at high speed. The fuel will be the mass that's the hardest to accelerate to the ships speed, causing very high drag, further slowing down the ship. Hopefully between the high fuel drag, ram drag, and the engines in full reverse, the Explorer class ship will reenter our home star system Sol. Decades older, probably worn out, and definitely antiquated, but loaded with data banks full of information. Ram Scoop collector and the bad news The problem with using an interstellar scoop, is their isn't much in interstellar space to scoop up. We found papers that proposed1000 km diameter scoops that only weighed 200 tons. Assuming your moving at 1/3rd the speed of light (100,000 kilometers per second) with a scoop area of 1000 km across (pi*R^2=pi(50,000,000cm)^2 = 7.854E15 cm^2). You'd be scooping up the mass in 7.854 E25 cubic centimeters of space. A big question is the composition of interstellar space. A classic assumption is that there is nothing out there but about 1 atom of hydrogen per each cubic centimeter of space. More recently, people guess it might as little as .054 atoms per cubic centimeter, or as much as 10. Even more recently than that (say the last few months) it has been proposed that there may be a lot of long-chain carbon molecules in space. Perhaps 60-200 atoms / molecules. These small, dark, heavy molecules might be the missing 90-99% of the mass of the galaxy (euphemistically called "dark matter"). So far, no one really knows. This is unfortunate, because the composition of the interstellar medium makes a hell of a difference in the design and feasibility of a Ramscoop or RAIR-based starship. If we assume one hydrogen atom per cubic centimeter (at a proton mass of 1.673 E-27 Kg), and assume we're running at 1/3rd light speed (0.333c). Our 1000 km in diameter scoop, would scoop up a ram flow of 131.4 grams per second. That's about 345 tons a month. That doesn't sound to bad unless you realize how much fuel our ship would need, and remember that the scoop weighs 200 tons (and you really want the mass at slower speeds). Given the amount of time the scoop could be used it couldn't scoop up enough to be very helpful. So this stardrive would go into the impractical bin. If on the other hand, you assume that each cubic centimeter had a hundred atom carbon molecule in it, the same scoop would give us over a thousand times as much mass to work with. Making a RAIR drive powered from stored fuel far more attractive. But since we don't know. Its hard to recommend this drive. ---------------------------------------------------------------------- Kelly Starks Internet: kgstar@most.fw.hac.com Sr. Systems Engineer Magnavox Electronic Systems Company (Magnavox URL: http://www.fw.hac.com/external.html) ---------------------------------------------------------------------- From popserver Tue Feb 27 20:30:19 GMT 1996 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["11264" "Tue" "27" "February" "1996" "14:20:09" "-0500" "Kelly Starks" "kgstar@most.fw.hac.com" nil "254" "Habitation Deck" "^From:" nil nil "2" nil nil nil nil] nil) Return-Path: kgstar@most.fw.hac.com Received: from most.fw.hac.com (gw1.magec.com [151.168.2.3]) by caritas.efn.org (8.7.4/8.7.2) with SMTP id LAA01722 for ; Tue, 27 Feb 1996 11:26:13 -0800 (PST) Received: by most.fw.hac.com (4.1/SMI-4.1) id AA06443; Tue, 27 Feb 96 14:23:12 EST Received: from unknown(151.168.254.82) by gw1 via smap (V1.3mjr) id smI006340; Tue Feb 27 14:21:07 1996 Received: by most (4.1/SMI-4.1) id AA11061; Tue, 27 Feb 96 14:21:02 EST Received: from ss4.fw.hac.com(151.168.145.199) by most via smap (V1.5khhunt) id sma011046; Tue Feb 27 14:20:11 1996 Received: from [151.168.146.187] (kgstar) by ss4.uiv (4.1/SMI-4.1) id AA10514; Tue, 27 Feb 96 14:20:06 EST X-Sender: kgstar@pophost.fw.hac.com Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39) To: KellySt@aol.com, hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu, lparker@destin.gulfnet.com, kgstar@most.fw.hac.com Subject: Habitation Deck Date: Tue, 27 Feb 1996 14:20:09 -0500 Heres some more text about the crew quarters centrafuge to look over. We probably fought out all the details months ago, but attack at will. Kelly ----------------------------------------------------------------------- Crew Quarters One large limitation in the starships design, is the habitation deck. The Space Settlements design study published by NASA (reference 1), pages 22 &;42 states that most people can adapt to rotation rates of up to 3 rpm, but that this adaptation might not be possible if personnel routinely move between the rotating 1 G. sections and the non-rotating zero-G sections of a space settlement or ship. The design study strongly recommended a rotation rate of less than 1 rpm. But that would require a habitat over 1600 meters across. A 3 rpm limit still requires a habitat 200 meters across, but this at least seems plausible for a large exploration platform. A 4 rpm rate would allow a 110 meter across habitat, but for purposes of this design I'll assume a 3 rpm rate. Putting this 200 meter in diameter ring in the ship, immediately means a very large ship. Since the ship's required speed will force it to accelerate and decelerate at high rates for months, the habitation decks will need to adapt to everything from zero G, to one G forward or backward. To do this, I'm assuming the habitation ring is made of straight tubes (gold tubes in Hab. Deck image), attached between struts radiating outward from a support centrifuge (blue green structure in image), which rides on the inner edge of a support structure (clear in image) that attaches directly to the inside of the ships outer hull. Each of the hab. tubes can be rotated around their long axis to turn the floor toward the direction of the currently active 'down'. (Rooms in the support centrifuge will need to be constructed so the outer, front, and back walls can be walked on.) For example: If the ship is accelerating (or decelerating) at nearly one gee, the centrifuges rotation can be stopped and the segments turned so their floors points toward the rear (or front) of the ship. If the ship is coasting, the floors will be turned to point outward and the habitat rotated at full speed. If the ship is accelerating or decelerating at less than one gee, the floors will be partially rotated, and the hab ring spun at partial speed. The Hab. Deck centrifuges are effectively independent space stations 660 feet across riding inside the Explorer class starships depresurized outer hull. The only direct connection between the hab deck and the ship are the tracks the centrifuge rides in and the electrical and data links. Each hab cylinder has its own life support and food storage in the centrifuge segment closest to it. Transit of food and material between the centrifuge and the rest of the ship is via pressurized shuttle cars riding on tracks inside the main centrifuge. This separation maximizes redundancy and isolation of the various areas. Each hab cylinder can be sealed off from the rest in case of fire or contamination. Even if all of the habitation centrifuge was to become contaminated, the pressurized areas of the rest of the ship would still have there own life support. Note that I have not considered spinning the habitat section of the ship on a tether, or spinning multiple ships tethered to one another. I'm not sure how well a tether (or the hab module) could handle years of unprotected exposure to relativistic plasma impacts, and spinning part of one ship (or two linked ships) could preclude magnetic shielding. Also, this method would not be practical while the ships were accelerating or decelerating, and it would make both shielding the hab module and allowing service access to the rest of the ship harder. Finally, this would greatly complicate the rest of the ship, the vast bulk of which should not be spun for gravity (or any other reason). Also consideration should be given to counter rotating habitat rings, or other counter rotating masses to compensate for torque on the ship. Otherwise the ship will need to use its attitude jets to compensate when it spins and de-spins the centrifuge. The Space Settlements design study , pages 26 and 32, list various breakdowns for crew living space requirements. Per person, these are: Requirement,Space (m^2) Residence,49.0 Shops/office,3.0 Hospitals,0.3 Parks/open space,10.0 Transportation,12.0 (tram / halls), **Subtotal,74.3 , Water/waste recycling,4.0 Service industry,4.0 Personal storage,5.0 other,3.0 Farm,60.0 **Subtotal,76.0 , **Total,150.3 m^2 These numbers were originally developed for space colonies and may be excessive for a starship, but given that the crew will spend almost all of their professional lives aboard the ship, it's probably best to err towards a more spacious design. Assuming each habitation ring is made of 12, 50 meter segments 10 meters in diameter with 3 m ceilings (more in the central halls and open areas) gives about 16,000 square meters of floor space (about 70 m^2 for up to 224 crew). If the hab ring is instead made up of 12 50 meter segments 20 meters in diameter with 3 m ceilings, you get about 63,000 square meters of floor space (about 70 m^2 for a crew of up to 898). These figures assume farm and/or personal and food storage are outside the full gravity section of the habitat. Of course, we might not need to do much (if any) farming, depending on the mass assumptions. The drawing above gives 792 people more open area then the above calculations would suggest. Which is probably necessary given how long the voyage is. People are housed two to an apartment/office. With a few single person apartments that can be converted to conference and lab areas. This should be a functional arrangement both for the trip, and for the exploration phase. While not as glamorous. Most people involved in space exploration do support and analysis functions. Only a fraction of the crew will ever leave the ship, and most of the science will be done back on the ship pouring over the data recordings. Thus the need for some office space and a lot of networked personal computers. Given the performance increases in computers. These personal computers should have hundreds of times the power and capacity of a human brain. (Makes you wonder what the software will be like? Or the ships mainframe!) Crew Quarters Radiation Shielding Normal radiation shielding is defined as mass per surface area of the area being shielded. The Space Settlements design study, page 125, lists that for protection of an inhabited volume outside the earths magnetic fields, the surface of the habitat must be covered by about .44 kilos per cm^2 -- 4.4 tons per square meter. This is roughly equivalent to an eight foot thick concrete wall. For 12, 50 meter long, 10 and 20 meter diameter segments wrapped in shielding mass, you get: 
(Surface area of cylinder      = Circumference of cylinder *
Length
of cylinder. Circumference of circle      =  pi * diameter)

                   Surface area               Shield mass
     PI * 10m * 600m = 18,849m^2     4.4 tons/m^2 =  82,939 tons
     PI * 20m * 600m = 37,698m^2     4.4 tons/m^2 = 165,876 tons


If instead you try to wrap the hab ring rotation area with fixed shielding,
you get a lot less torque on the ship. Unfortunately, you also have a
greater area to cover.

Say a shielding a 10m length of the outside of the hull cylinder with
shield 'bulkhead' walls extending 25 meters in from the surface of the
hull. (The 50 x 10 meter tubes would come in 14 meters from the hull edge
in the middle of their span.) (100m -[cos(15deg)*100m] = 3.4m of gap
between the floor and the outer hull at the center of the hab. tubes. Plus
the diameter of the tube.).



(Surface area of cylinder = Circumference of cylinder * Length of
cylinder.
Circumference of circle      =  pi * diameter, 10 meter length)

          = pi*200m
          = 628.3 meters

     Multiply by 10 meters length and you get a surface area of
     6283 square meters.
     Multiply by 4.4 tons per M^2 of surface,

          = 27,646 tons of shielding mass.


For each of the washer shaped shield bulkheads.


(Area of circle      = pi*r^2)
          = pi*(outer_radius^2 - inner  radius^2)
          = pi*(100m^2 - 86m^2) =pi*2604=8.180m^2 of surface,
          = 35,995 tons of shielding mass.

Forward bulkhead,35,995 tons
Rear bulkhead,35,995 tons
Outer circumference,27,646 tons
Total,72,017 tons of shielding mass.




72,017 tons would sink an aircraft carrier, but it is a little less than
just shielding the 10 meter hab-segments. On the other hand if you assume
20 meter diameter segments the shielding only goes up to 176,242 tons. Only
slightly heavier than just wrapping the 20 meter tubes. Also note that if
you use a u-shaped fixed shield (as shown in the graphics image) you could
save quite a bit of mass. Multiple centrifuges sharing the same u shaped
shield could save over a third of the shielding mass of independent
shields.

Hoping I got something wrong, I checked these numbers against the Stanford
torus space colony design. (10,000 person, 69,000,000m^3 of volume
[8,000,000m^3 of personal space]) That torus was had a ring 135 meter in
diameter, and full torus diameter of 1800 meters.


Mass numbers:
       210,000.  tons of structure,
       530,000.  tons of internal mass
          (242,000.  tons moist soil,
           260,000.  tons buildings, trams, cloths etc,
            20,000.  tons water).
     9,900,000.  tons of shielding mass total.


Scale the monster down to our hab ring and my numbers seem to be in the
right mass range. For a space colony, shielding mass is just a launch cost.
For a ship of course, its extra weight that has to be moved. Also note that
I only fully shielded the habitation zone. The rest of the ship, the areas
the crew may need to work in, is not. Also note that this shielding is only
enough to keep the crew safe from the radiation loads a flaring star would
put on them. If you want to shield against radiation from particals the
ship slams into (a very good idea at high speeds) you probably should put
the crewed areas of the ship behind the fuel tanks.

On the good news side. We were considering a Ram Augmented drive ship. The
magnetic fields needed to do that can also shield the ship. Also for the
vast bulk of the mission time we can wrap the hab ring with reaction mass
or fuel tanks. If we save these tanks for last, or as emergency reserve
tanks, the crew can be shielded by mass we need to take along anyway. Water
for example weighs about 62 lbs per cubic foot and makes a good reaction
mass for the auxiliary thrusters, or to spike the main drive. We would
probably want to carry along a lot of water and ammonia (H2O &;NH3), so we
could break them down to provide oxygen and nitrogen to replenish lost
atmosphere. Lets face it, this thing will leak. (Everything does
eventually.)




----------------------------------------------------------------------

Kelly Starks                       Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html)

----------------------------------------------------------------------


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	["901" "Tue" "27" "February" "1996" "17:09:39" "-0500" "David Levine" "David@interworld.com" nil "21" "Nuclear Liquid Salt Reactor" "^From:" nil nil "2" nil nil nil nil]
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From: David@interworld.com (David Levine)
To: Kelly Starks x7066 MS 10-39 
CC: KellySt@aol.com, hous0042@maroon.tc.umn.edu,
         T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org,
        jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
         rddesign@wolfenet.com, bmansur@oc.edu, lparker@destin.gulfnet.com
Subject: Nuclear Liquid Salt Reactor
Date: Tue, 27 Feb 1996 17:09:39 -0500

I don't remember if this has ever been discussed here, but
I just saw this on sci.space.tech:

-David

===========================================================
>
>BTW I've just seen an old Zubrin proposal for a Nuclear
>Liquid Salt Reactor. You take moderately enriched fuel
>in several tubes to a larger tube where the uranium goes
>critical and passes out the back through a nozzle. With
>a careful adjustment of the fuel flow there is a constant
>region of criticality. Low radiation on the vessel because
>all the gunk is in the fuel. He proposed it for LEO use. I
>liked it myself. Anyone seen a serious proposal for its use?

No, but I can think of a few. Such a vehicle would
be able to sustain multi-G accelerations for days!
Plus, the exhaust has a v(esc) higher than solar
escape v, so it's perfectly safe. Just don't tailgate!
===========================================================

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From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39)
To: David@interworld.com (David Levine)
Cc: Kelly Starks x7066 MS 10-39 , KellySt@aol.com,
        hous0042@maroon.tc.umn.edu, T.L.G.vanderLinden@student.utwente.nl,
        stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
        rddesign@wolfenet.com, bmansur@oc.edu, lparker@destin.gulfnet.com
Subject: Re: Nuclear Liquid Salt Reactor
Date: Wed, 28 Feb 1996 08:12:58 -0500

This is a weird one.  I'm sure I never heard of it before.  Sounds like the
exaust would be a mess, and you'ld have a lot of radiation and nutron
bombardment on the ship when the engines runing. Wonder whats the specific
impulse?

Kelly


At 5:09 PM 2/27/96, David Levine wrote:
>I don't remember if this has ever been discussed here, but
>I just saw this on sci.space.tech:
>
>-David
>
>===========================================================
>>
>>BTW I've just seen an old Zubrin proposal for a Nuclear
>>Liquid Salt Reactor. You take moderately enriched fuel
>>in several tubes to a larger tube where the uranium goes
>>critical and passes out the back through a nozzle. With
>>a careful adjustment of the fuel flow there is a constant
>>region of criticality. Low radiation on the vessel because
>>all the gunk is in the fuel. He proposed it for LEO use. I
>>liked it myself. Anyone seen a serious proposal for its use?
>
>No, but I can think of a few. Such a vehicle would
>be able to sustain multi-G accelerations for days!
>Plus, the exhaust has a v(esc) higher than solar
>escape v, so it's perfectly safe. Just don't tailgate!
>===========================================================


----------------------------------------------------------------------

Kelly Starks                       Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html)

----------------------------------------------------------------------


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From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39)
To: KellySt@aol.com, hous0042@maroon.tc.umn.edu,
        T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org,
        jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
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        lparker@destin.gulfnet.com
Subject: Mission type
Date: Wed, 28 Feb 1996 09:45:02 -0500

Mission Flight Type


This is a summary of the various types of flights we might use to send a
mission to another star (Round trip, pick-up and return by follow on
flight, construction of return equipment at target star, Multi-star,
Multi-generation, hibernation, and one way).  It breifly describes each
flight type and its advantages and disadvantages.



Round trip

Ship and crew return to Earth at mission end.

Advantages

*Simplest option, and one with little likely hood of public objection.

*More likely to get more volunteers and better qualified volunteers for flight.

*This option implies that the mission is fairly short. I.E. within the
professional life of the crew. This would imply its short enough to return
information in a useful amount of time. (I.E. it would get there and back,
before a later faster flight could do it.)

*It would return far more information than an interstellar communications
link could manage.

*It obviously avoids the grisly public relations and crew morale problems
of a one way mission.

Disadvantages

*Technically more challenging. Getting a ship to the target starsystem is
hard enough. Getting it back would make it harder. But this must be traded
off against the added complexity of a ship capable of supporting its crew
for the rest of their lives.

*It has to be a fast enough ship to get back in an acceptable amount of
time. Too slow and theirs no practical reason to send it.




Pick up and return by follow on flight

Advantages

*Most of the advantages of the round trip model, and would allow the first
ship to be a mobile research station or other specialized ship, with faster
courier ships providing round trip flights.


Disadvantages

*High risk and more complicated. Multiple ship types, and concerns that the
first ship might be left stranded. The multiple ship types (the first being
a big heavy slow boat, the latter faster smaller ships) is probably
manageable and might even have advantages. The problem of assured crew
return would have to be handled conclusively.



Crew constructs equipment for return flight

This option come up with light/microwave sail craft, beamed power craft,
and fuel launcher craft. The crew would construct automated duplicates of
the systems that launched the ship from Sol space.

Advantages

*Would establish launcher facilities in both star systems. Which could
allowing faster two way flights with specialized fast light ships.

*The crew might get back faster with their ship using the constructed
launcher systems for assistance.

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From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39)
To: KellySt@aol.com, hous0042@maroon.tc.umn.edu,
        T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org,
        jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
         rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu,
        lparker@destin.gulfnet.com
Subject: Future tech
Date: Wed, 28 Feb 1996 09:45:51 -0500

Future tech


The engineering and science we have now, and assumed we will have in 2050,
will change.  Fusion, fission, relativity, quantum mechanics, and a host of
other fundamentals of current physics; were all discovered within the last
hundred years.  We can conservatively expect physics to change far more in
the next hundred years, then it did in the last hundred.  What technologies
we will have on hand in a century or two are impossible to guess.  We could
have matter conversion, hyperlight drives, new understandings of inertia
and kinetic energy, nanotech, hyper intelligent A.I.s, or all those and far
more.  Any of these would dramatically effect our ability to travel between
the stars.  So even though we can't come up with any practical ideas for
exploring the stars now, we can be sure our descendants will find it far
easier than we imagine.

The reason we in the L.I.T.  group assumed few new technologies, is that we
could quickly wind up in a science fiction argument as apposed to a
starship design project.  Not only don't we know which revolutionary
technologies will developed by 2050 (50 years ago, would you have believed
the incredible stuff we have now?), but assuming any major advance changes
everything else in the project.

For example: a couple of technologies frequently talked about are:
Nanotech, self replicating machines, and Artificial intelligences with
human or greater levels of intelligence.  These obviously are related
fields, but the effects they'd have on the rest of the mission are
dramatic.

Nanotech
Nanotech is a set of technologies currently under research that would build
machines the size of complex integrated molecules.  In theory; such
machines working together, could tear a mountain full of ore down, atom by
atom, and reassemble it into manufactured products.  They could do this so
quickly the mountain would flow into its new forms like it melted.  Virus
sized robots could cruise through our cells and repair anything from
radiation induced mutations to any form of disease or injury.  They may
allow virtual immortality and eternal youth.  And their promoters expect
them to be commonly available by 2050.

This could allow the ship to become fully self repairing down to the
molecular level.  A semi living machine that could continue indefinitely
without any concern for wear and tear.  Populated by near immortal,
superhuman, crews.  Able to manufacture almost anything, to any scale, with
little if any human assistance.  Need a massive infrastructure in the
target star system? Drop a set of these and they will transmute a continent
to build it for you.

Obviously this starts to eliminate almost any normal physical limits of the
ship and crew.  The side effects on human society are incalculable.  Would
such super humans: be to preoccupied to explore the stars? To powerful and
impatient to take a long slow flight, or so long lived that adding a few
decades to the trip would mean nothing to them.


Self replicating machines
Say you can't build molecular sized machines, but you can build small
adaptable robots that can make copies of themselves.  They can still
revolutionize automation.  Can still be dropped on a world and told to
restructure a continent to serve our purposes, or mine anything we need in
whatever amount.  That would be very valuable if you need to large scale
mining or infrastructure construction to get home, or do extensive
exploration of all parts of all the worlds.

Note that this doesn't assume the machines are intelligent or completely
autonomous.  After all Bees can build pretty complex structures by
following a few rules.  Perhaps self replicating computers can do as well.
On the other hand we've never come close to making a factory that could run
unattended for very long, much less fix or rebuild itself.  Some studies by
NASA show that such things might not be possible without humans to keep
everything running.  But things might be a lot different in half a century.


Artificial intelligences with human or greater levels intelligence.
We already build and sell super computers with more power and data capacity
then a human brain.  In 20 years that should be the capacity of a good home
computer.  What we can't do is figure out how to teach these brains to
think.  Will we be able do that by 2050? Will our ship be totally
automated? Assembled by robots, and capable of doing all the exploration
itself? Will it be filled with a crew of robots, or a mixture of robots and
humans?


Decisions decisions.
Unless we said otherwise we assumed none of these technologies is in use on
this project.  The implications just get to bizarre.  Any of the
technologies listed above would turn all of Earth culture inside out.  Or
any of the dozens of other similar technologies We didn't discus, or think
of.  After a lot of arguing we decided to assume that no fantastic
discoveries are made in science and technology in the next 50 years.  Which
we all agree, is the least likely assumption we could possibly make.


----------------------------------------------------------------------

Kelly Starks                       Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html)

----------------------------------------------------------------------


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From: kgstar@most.fw.hac.com (Kelly Starks x7066 MS 10-39)
To: KellySt@aol.com, hous0042@maroon.tc.umn.edu,
        T.L.G.vanderLinden@student.utwente.nl, stevev@efn.org,
        jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl,
         rddesign@wolfenet.com, David@interworld.com, bmansur@oc.edu,
        lparker@destin.gulfnet.com
Subject: Mission purpose
Date: Wed, 28 Feb 1996 09:50:43 -0500


Mission purpose


Why do we want to go to another star anyway? We obviously have to want to
do it pretty badly, or we would never pay for all this. Presumably this
isn't some kind of cold war stunt. We certainly aren't likely to get any
immediate financial benefit. We absolutely don't have any problems back
home (hunger, famine, mineral depletion, etc..) that this could help. So
what do we want out of the flight?


Exploration of the planets and moons in another star system

Advantages

*Very popular idea with public.

*Possibility of tremendous scientific returns.


Disadvantages

*Expensive. You'd need a huge ship to carry all of the hundreds of
researchers, surveyors, and all the support staff and advanced equipment it
would take to do even a minimal job of surveying a new star system.

*A planet with a Earth-like ecology it would be a biological death trap.
Alien microbes, allergens, and other unknowns life forms would easily
defeat unprepared Earth mammalian immune systems. The ground teams would be
in an area that would be worse, to them, than biological war back on Earth.

*On a planet with a non-Earth-like ecology it still could be a biological
death trap, and in addition have basic climate and biosphere
incompatibilities (Wrong temperatures, air pressures, gravity).

*This is a massive undertaking. You'd only try it if you really wanted to
explore. This would require a major national (or international?)
commitment.




Colonization of planets or moons

Advantages

*Very popular idea with public.

*Excellent staging area for direct examination of that planet or moon.


Disadvantages

*Expensive. Either the colony would need to be the size of a major city to
support all of the specialists needed to support a self sustaining society,
or regular (extremely expensive) supply flights from earth would be
necessary.

*On a planet with a Earth-like ecology it would be a biological death trap.
Alien microbes, allergens, and other unknowns life forms would easily
defeat unprepared Earth mammalian immune systems.

*On a planet with a non-Earth-like ecology it still could be a biological
death trap, and in addition have basic climate and biosphere
incompatibilities (Wrong temperatures, air pressures, gravity).

*Isolation from resources. Ores, energy and raw materials are far harder to
access on a planet than in space.

*Isolation from other planets.

*Their doesn't seem to be enough practical justification for such a massive
undertaking. Again, it would require a major commitment or resources. Which
means a major public interest.



Colonization of constructed space platforms

Advantages

*Still may be a very popular idea with public.

*Excellent staging area for examination of the solar system.

*Much lower biological threat than on a planet with biosphere.

*The internal gravity, radiation, and environment can be precisely tailored
to humans.

*Far easier to construct and service than a planet bound colony.

*Easy access to plentiful resources. (Space is considered so much richer in
cheap, easy to access resources and power. That it is expected that Earth's
heavy industry will migrate into space in the next century.)

*Could act as a servicing center and supply port for the starship, or
subsequent starships.


Disadvantages

*Expensive. Either the colony would need to be the size of a major city to
support all of the specialists needed to support a self sustaining society,
or regular (extremely expensive) supply flights from earth would be
necessary.

*Their doesn't seem to be enough practical justification for such a massive
undertaking. Again, it would require a major commitment or resources. Which
means a major public interest.




Infrastructure construction

Advantages

*This could establish facilities necessary for routine, lower cost, flights
between home and this starsystem.

Disadvantages

*Construction could take so many resources that little or no exploration
will be done.

*Less interesting to public than an exploration or colony program. So it
might have a harder time getting funded. But it could be part of a first
flight the opens up the star system for larger follow on flights.

*Could be very expensive.


----------------------------------------------------------------------

Kelly Starks                       Internet: kgstar@most.fw.hac.com
Sr. Systems Engineer
Magnavox Electronic Systems Company
(Magnavox URL: http://www.fw.hac.com/external.html)

----------------------------------------------------------------------


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From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu,
        zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu,
         rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu,
        lparker@destin.gulfnet.com
Subject: fnrg: 'COLD FUSION' BREAKTHROUGH
Date: Wed, 28 Feb 1996 21:23:22 +0100

Hello,

I'm listening in on the free energy newsgroup since a few days, today I got
the attached message. I'm really wondering if it works that good.

Timothy



This file is taken from the Institute for New Energy Web Site at:
     www.padrak.com/ine/

If you are at all interested:  See the new (2/25/96) Subject Index at:
     www.padrak.com/ine/SUBJECTS.html

'COLD FUSION' BREAKTHROUGH

Have 15,000 Energy Pros in Anaheim Seen the Light of a New Era?

From:  Atlantis Rising, Number 6, 1996, pp 37 and 56

By:    Jeane Manning

Copyright Atlantis Rising.

Did a clean energy era just slip into our lives, unnoticed by mainstream
news cameras?  Its arrival may coincide with the recent success of an
unpretentious "cold fusion" device, reported to put out a thousand times
more energy than it takes to run it, at the world's largest trade show for
electric power producers.

(Cold fusion is the popular term for what the Japanese more accurately call
New Hydrogen Energy Technology.  See David Lewis' introduction to cold
fusion in Atlantis Rising # 2.  In 1989 Drs. Martin Fleischmann and Stanley
Pons were first to claim to have produced nuclear reactions by putting
palladium rods in water cells and getting excess energy out.  They are now
in a million-dollar laboratory in France, funded by Japanese money.)

Clean Energy Technologies Inc. (CETI) of Texas is a small company that
doesn't hesitate to walk among giants of the fossil fuel and nuclear
industries. CETI booked a booth at the Power-Gen '95 Americas conference in
Anaheim, California, and demonstrated their breakthrough nonpolluting
energy device, invented by James Patterson, Ph.D.  Earlier, at fusion
conferences, they proved that the Patterson "cold fusion" cell, the size of
your thumb, outperforms fusion reactors the size of factories by putting
out eighty times more energy, in the form of heat, than the electricity
that runs it.  While the Tokomaks of the megabucks world-huge donut-shaped
structures pervaded by high-intensity magnetic fields-attempt fusion of
atoms and are rewarded with brief bursts of less power-out-than-in
accompanied by dangerous radiation, CETI's and other room-temperature "cold
fusion" experiments quietly and cleanly put out more power than it takes to
run them and they keep this up for weeks at a time.

[Large picture of two men holding a small device about the size of a tennis
ball]

"Dr. James Patterson and CETI's Jim Reding are ready to take on the energy
establishment./ Photo from "Infinite Energy" [Magazine]."

Meanwhile, as if in a parallel but outdated universe, a physics professor
at the University of British Columbia sputters when I ask about cold
fusion.  "There is no such thing!  That has been proven to be just bad
science!"

In the Anaheim conference, where more than 15,000 engineers and other
visitors showed up from 75 countries, foot traffic was heavy at the CETI
booth.  The company's most impressive demonstrations, however, took place
in their hotel room for select groups.  Scientists who witnessed or knew
firsthand witnesses of various tests of the device at the power-generating
meeting gave me varying reports on CETI's demonstrations.  The most
conservative report was "sixteen to one" (more output than input), and
other witnesses said "one thousand times more power out than went in."

No matter which numbers we look

Continued on Page 56

COLD FUSION, Continued from Page 37

at, the fact remains that a four-inch long (by one-inch in diameter) tube
of metal-coated beads and ordinary water, put out a kilowatt (a thousand
watts) of power in equivalent heat with only about one watt of electricity
going in.  Water flowed through it and out into coils of plastic tubing
while an electric fan blew the room's air past the coils.

"My colleague was there and could feel the hot air coming out,' says Eugene
Mallove, Ph.D., editor of "Infinite Energy Magazine."

Why didn't the company make a bigger splash by keeping the device running
day and night on the floor of the convention center?  Mallove says he
believes CETI came to the conference to nail down a contract with a
multi-billion-annual-sales corporation, so the hotel room was the site of
high-level negotiations. "They went there to give further encouragement to
this very large, Fortune 500 company or maybe even Fortune 100 company in
the United States."  Mallove said in December that the corporation either
has already, or probably will shortly, make a deal with Clean Energy
Technologies to license the technology for manufacturing and production of
these reactors.  Who is the mysterious giant?  "It is not an energy company
per se. It is a very high-tech, instantly recognizable corporation."

Mallove is expected to reveal more in the next issue of "Infinite Energy",
promising details on the testing of the CETI cell at the PowerGen 95
convention.

Mallove reports that CETI representatives ran their tiny cell for five
hours with only about 1.4 watts going in but 1,344 watts were coming out.
It was able to heat a room;  in fact, the CETI crew had to call the hotel
desk and have room service increase the air conditioning for the room.

"They reduced the output power at one point to about 470 watts, for safety
reasons, but the input power at that point was .1 watt (one-tenth of a
watt).  So the ratio at that point was 4700 to one.  We're talking about
some gigantic ratios-for all practical purposes, no input power, and it
will be shown ultimately, of course, that input power if needed at all can
be generated easily thermoelectrically and just fed back.  So the whole
thing, for all practical purposes, is a self-sustaining unit to heat
anything you want!

This working prototype of a "cold fusion" heating unit shows more
performance than glitz.  "Frankly, the whole apparatus looks like a science
fair project," Mallove told me.  "Of course, most of the important
inventions in history looked like that in their prototypes.  And it wasn't
designed to be a commercial heating unit; it was a demonstration unit."

It may not look like much, but if someone made multiples of the unit and
put it in your basement, Mallove says, they could heat the whole house
for a fraction of the cost of an electric light bulb.  "In theory, if I
wanted to have something like that and CETI was willing to sell units to
me, they could heat this house in New Hampshire even in the bitter cold."

[Picture of the inside of a large donut-shaped metal hot fusion device.]

"Princeton's Hot Fusion project.  Dinosaur?"

Is it reliable?  "This is not the old days of cold fusion where you do some
finicky experiment and hope and pray that it works," replies Mallove.  "It
works every time."

The CETI process starts very rapidly.  "First, you apply a heater to it,
equivalent to an automobile electric starter.  You have to get it to proper
temperature first. Then you remove the heater ... and the thing just goes."

But can it replace internal combustion engines?  Mallove is optimistic.
"Since there is no known upper limit to the pressure under which it can
operate, there is every indication that fairly quickly, people will develop
this for steam production.  And I fully expect that in 1996 a vehicle will
be powered by this process."

Mallove is of course not predicting it will be in the stores next year, but
we do know researchers who want to be first to put a new-energy device into
a small vehicle and drive across the country.

CETI is more interested in getting into production than getting into
newspapers.  The company is not returning phone calls from journalists;  it
is bombarded by would-be purchasers. Their marketing strategy is to sell
distributors' licenses to a relatively small set of serious groups and
businesses.

Paralleling the dramatic improvements in "cold fusion" are advances in
magnetic motor technologies.  Mallove says he strongly suspects they are
closely related.  I've interviewed additional scientists who speculate that
"cold fusion" processes, and magnets, tap into a free energy universally
present in the space around us.

For example, even though as a mainstream engineer/physicist he shuns the
word overunity (meaning he is not publicly claiming
more-power-output-than-input), Yasunori Takahashi from Japan is stirring up
the new-energy scene with his magnetic motor.  He claims to have the
world's most powerful permanent magnets and is looking for business
partners in the U.S. and England to produce the motor.  New-energy
researcher Christopher Tinsley rode a motor scooter powered by Takahashi's
"Self-Generating Motor" throughout London for about a half hour and reports
that the motor remained cool, which is highly unusual for a motor.
Although it does need four 12-volt batteries to spin the motor up to speed
for startup, a professor from London University said the motor seems to go
500 miles without fuel.  New Energy News, monthly publication of the
Institute for New Energy based in Salt Lake City, reports that Takahashi
also invented an extremely powerful small capacitor (energy storage unit)
and a Battery Doubler which promises to extend the running time of laptop
computers, cellular phones and camcorders.

These are among many promising new-energy technologies emerging around the
world.

Mallove sees the irony in the recent scene at Anaheim Convention Center.
There were a thousand exhibitor booths, all sorts of megaproject
technologies from oil, coal, gas and nuclear fission - "all this stuff
that's going to die completely, with this one (CETI) booth being the most
important booth at the entire meeting. But you know the story.  The
dinosaurs did not realize their demise."


Jeane Manning is co-author of several books including "Angels Don't Play
This HAARP" (distributed by Book People).  Her first solo book, "The Coming
Energy Revolution" will be out in spring, 1996, from Avery Publishing
Group.

For anyone who wants to learn about the emerging scene, the International
Association for New Science is planning a conference on new energy
technologies for April 25-28, 1996 in Denver.  The IANS office is in Fort
Collins, Colorado, phone (970) 482-3731.




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From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
To: KellySt@aol.com, stevev@efn.org, jim@bogie2.bio.purdue.edu,
        zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu,
         rddesign@wolfenet.com, David@InterWorld.com, bmansur@oc.edu,
        lparker@destin.gulfnet.com
Subject: Misc.
Date: Wed, 28 Feb 1996 21:23:45 +0100

To Kelly,

Most of your letters sounded familiar, only two things I want to say:

Draft text Externally fueled Fusion drive
===========================================================================
>Because of the deceleration fuel limitation, it is unlikely that the ship
>can get to more than a quarter or a third of the speed of light.  But
>that's still a 100,000 kilometers per second.  The ship will need to
>protect itself against impacts.  One of the simplest ideas is to push
>several miles of charged dust ahead of the ship.  Ramming a cloud of
>charged iron dust at a 360,000,000 kilometers per hours will turn most
>anything into ionized plasma.  Which can be shoved ahead of the ship, or
>off to the sides, by the charges dust cloud handler.  Effectively most
>anything you run into at speed will become more shielding dust.

How do you shove a few kilometres of clouds? Especially during acceleration
and deceleration a lot of cloud-rebuilding will be needed.


Habitation deck
===========================================================================
>One large limitation in the starships design, is the habitation deck. The
>Space Settlements design study published by NASA (reference 1), pages 22
>&;42 states that most people can adapt to rotation rates of up to 3 rpm,
>but that this adaptation might not be possible if personnel routinely move
>between the rotating 1 G. sections and the non-rotating zero-G sections of
>a space settlement or ship. The design study strongly recommended a
>rotation rate of less than 1 rpm. But that would require a habitat over
>1600 meters across. A 3 rpm limit still requires a habitat 200 meters
>across, but this at least seems plausible for a large exploration platform.
>A 4 rpm rate would allow a 110 meter across habitat, but for purposes of
>this design I'll assume a 3 rpm rate. Putting this 200 meter in diameter
>ring in the ship, immediately means a very large ship.

One may not need a complete ring. Just a habitation "cube" at the two ends
of a long "bar". Then just turn this bar around, thus the ends making a
common circle. It is in fact just a the torus mentioned above only