# Re: Re: Summary A

```>> 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

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

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