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starship-design: This and that.
Hello everyone,
I've been a little withdrawn lately, but now that school is over, I will
be more active.
I've just plowed through the latest messages, and I have a few questions
and suggestions:
Questions:
To: Steve VanDevender
Re: Traveling Faster Than Light.
In message dated Sun Jun 15 1997 you write: (reformated)
> More importantly, relativistic physics, as we now know it,
> does not in any way prohibit a material object from traveling
> at any speed less than C, but does prevent anything from traveling
> faster than that.
It is my understanding (limited though it may be) that Einstein's
equations do not prohibit travel FASTER THAN the speed of light,
but only prohibit travel AT the speed of light. Is this not correct?
To: Steve VanDevender
Re: Talking Faster Than Light.
In message dated Sun Jun 15 1997 you write: (reformated)
> The few FTL effects that are thought to exist in particle
> physics don't translate to macroscopic objects, and even
> when postulated don't transmit information or mass faster
> than light.
Again, my limited understanding tells me that communication via
particle/wave duality phenomenom is possible. Via the following method:
1) Generate a single photon every 1/100 second.
2) use a beam spiltter to give the photon a 50% chance of:
3a) going to your friend (or enemy) at Tau Ceti.
-or-
3b) into a trap for 12 years (perfect reflectors, whatever)
Once the other photon has had enough time to arrive at Tau Ceti, send
your 12 yr old photon into a double slit experiment. Your friend (or
enemy) does the same. You both observe the pretty, pretty, interference
pattern.
Now comes the tricky part:
You turn on a particle detector and are able to decide exactly which
slit the photon went through. of course, your interference pattern
disappears, but
SO DOES THE OTHER GUY'S (and at the same time too)
After sending your morse code message, you turn off your particle
detector and stare at the interference pattern again (pretty... 8)
Suddenly the pattern begins disappearing in an orderly fashion as your
friend (who is now your enemy for ruining your interference pattern)
transmits his message:
>>Hey, thanks a lot, JERK! you riuned my interference pattern :( <<
Aside from the obvious technical problems of observing the same photon
at the same time (whatever "same time" might mean)(and BTW I can finagle
around that one too if you insist.) This method should allow FTL
communication. and temporal communication as well. Causality be
damned.
To: all
Re: support of Kyle
First let me (mis)quote Clark's first law:
"When an intelligent but young scientist says that something is
possible, he is almost certainly correct. When an elderly but
distinguished scientist says something is impossible, he is almost
certainly incorrect."
As an example of this I direct your attention to the well-known and
oft-quoted "fact" that it is impossible to gain information about a
particle without interacting with it.
In a recent issue of Scientific American (I think it was Nov 96), it was
demonstrated
how one can gain information on a particle without interacting with it.
a brief (and no-doubt garbled rendition is provided here)
Consider the following setup.
D1
i
i
(a)
D0 m/--------B/S ii i D2
| | |
| |(a) |(b)
| | |
DS---------B/S--------/m
/ (b)
/
S
Legend:
S - Single Photon Source
DS - Downshift crystal (turns one photon into two photons of half
energy)
B/S - Beam Splitter. "/" indicates orientation.
m/ - Mirror. "/" indicates orientation.
i - interference pattern caused by equal probability of photon
taking either path (a) or (b).
D0 - detects existence of photon in down shift crystal (and therefore
in the rest of the experiment as well.)
D1 - Set in a dark band of the first interference pattern.
D2 - Set in a bright band of second interference patter.
Photons may take both path (a) and path (b) simultaneously. they can do
this because they behave as a wave.
As drawn, each and every photon generated will produce the following
result:
D0 D1 D2
on off on
Now consider what happens when a particle P is placed in the beam path
at (a):
D1
?
?
?
(a)
D0 m/----P B/S ??? D2
| | |
| |(a) |(b)
| | |
DS---------B/S--------/m
/ (b)
/
S
Legend:
P - Particle to be studied:
?? - photon path depending on whether reflected at second B/S or not.
Now since the photons cannot take both paths simultaneously, each photon
must take path (a) or path (b) with a 50% chance.
if path (a)
photon (as particle) absorbed
both D1 and D2 dark - experiment invalid, particle ruined
else
photon (as particle) encounters second B/S
if reflected to D2
D1 dark D2 bright - no information (same as if P not there)
else
D1 bright D2 bright - SUCCESS Particle P exists!
endif
endif
But lets check that light path:
D1
|
|
|
|
D0 m/ P B/S D2
| |
| |(b)
| |
DS---------B/S--------/m
/ (b)
/
S
As you can see, the light never touched particle P. It is still in
whatever
state it was in when the experiment began.
The Question I have:
1) Why did the photon (as a wave) disappear from path (a)?
2) How did the photon "know" to stop behaving as a wave and start
behaving as a particle?
3) if such a well-established princple of PHYSICS can be dashed by a
simple thought experiment (which anyone could have done in the last 50
years but didn't)
Then how can we say that FTL is impossible?
It seems to me that Kyle has done a good first order approximation of
his star drive. He has told us the energy cost (10,000 times higher
than the M.A.R.S. drive ;) ), it's rough size, shape and mass.
He has explained the first princples of it (although he claims it is
Non-Alcubierre FTL, (E-mail dated Mon, 09 Jun 1997) it looks a lot like
the Alcubierre method)
You may say: "But how can one generate such a tremendous negative energy
(or gravitation) gradient?"
This is a valid question, but we might as easily ask Kelly how he
intends (exactly now) to initiate a sustained fusion burn in his
explorer class engines. We have the *feeling* that sustained controlled
fusion is possible, but the only demonstrated method requires
temperatures and pressures found only in the core of a star. (H-bombs
don't count, not controlled or sustained)(break-even fusion don't count
either)
Granted that we are a hell of a lot closer to fusion that we are to ZPE
or FTL, but then in 1970 we were much closer to fusion than we were to
personal computers. Now personal computers are everywhere and fusion is
still a pipe-dream.
Kyle, you have a lot of work ahead of you, you are going to have to
explain in much greater detail each step of your design. I suggest you
start with ZPE even if FTL doesn't work, the energy from ZPE will be
useful to other designs. expect much critisism and argument from Steve
and Tim, but don't take it personally. they are not trying to be mean
and nasty, they are trying to help you by making you state what you mean
in very precise terms. If you get stuck on the math, ask nicely, and
you'll be surpirsed at how helpful they can be.
If you look through all the old archives, you can see the same pattern
when I brought up the MARS design. Steve, I especially remember you
telling me that there was "no way" the sail could take in photons, and
derive enough momentum in the reation mass to overcome the momentum
gained by the sail. It wasn't until Tim solved the equations and proved
that it was possible that you relented (although to be honest, my
numbers and physics were far more out of whack than yours.) And I
suspect that Tim did it more to prove me wrong and shut me up than to
help me. ;)
The Mars design has some serious Engineering problems, but the basic
physics are sound, you can travel at near light speed if you can spend
about 1E18 Joules for two and a half years straight.
But FTL would be better, and ZPE would solve all of my transmitter
problems :)
Well, that's enough physics for now. I have some things to say about
generating Oxygen for the trip.
To: all
Re: Oxygen.
I have figured out a way to recycle all the oxygen (and even extract the
Oxygen locked up in the Stored food.
Basic Food equation:
C H O + 6 O = 6 CO + 6 H O
6 12 6 2 2 2
As I've said before, the Water can be split into Oxygen and Hydrogen but
what about the CO2? We must continuosly dump it into the exhaust, or
otherwise get rid of it. But then i was thinking about the following
equation in a book I had read.
900c
24 H + 6 CO = 6 CH + 12 H O
2 2 4 2
The products of both electrolysis reactions is: 18 H2 + 9 O2. So we
must supply 6 H2 for each molecule of sugar.
Now This assumes that we have a lot of heat, but that's true of all the
designs I've seen so far. (except FTL of course) The methane is then
used in further synthetic reations to make the various chemicals we
might need, or it can be dumped into the exhaust stream to increase the
mass flow in the thrust.
If our hydroponics are supplemented by stored food supplies, Then a
bigger problem might be Oxygen retention, rather than lack of Oxygen.
--
Kevin "Tex" Houston http://umn.edu/~hous0042/index.html
Webmaster http://www.urly-bird.com/index.html
"Whoever undertakes to set himself up as a judge of Truth and
Knowledge is shipwrecked by the laughter of the gods." A. Einstein
PS I have a new job, I'm a webmaster at Onelink Communications.
http://www.onel.com/
I didn't do that Website, so don't bother to tell me how bad it looks.