From: Luke Howison (lukeh@ihug.co.nz)
Date: Tue Dec 12 2000 - 02:39:41 MST
Hi spike and Extropians,
Amara Graps (>>) and spike (>) wrote:
> > Amara Graps wrote: My dear Spike, you are the third person who has asked
> > me that question in the last several months (the other two being Eric
> > Drexler and
> > Robert Bradbury).
>
> WOW cooool, Drexler, Bradbury, spike. There are three names I
> like to see mentioned in the same sentence.
I feel I am almost in the presence of three gods . . .
> Heres how I figure: an astronaut is usually at least 30 and human
> life expectancy is about 75, so 45 years to cover... lets see, the
> nearest star is about 4 light years and some change I think, so
> about 0.1c to get there in a lifetime, neglecting acceleration and
> deceleration phases.
What are octogenarians going to do in a distant star system?
> Assuming away the inherent difficulties in actually pushing a
> vehicle to that speed, the erosion as a function of interstellar
> matter becomes a hell of a problem. I did a calc today assuming
> an iceberg shield up front, as in Clarke's Songs of Distant Earth.
(snip)
> The erosion rate I got for .1c was on the order of a cm a day,
> using some admittedly rough estimates.
Don't panic, spike; may I suggest some more things to try . . .
1. Metallic shield --> takes a lot more damage, although it has more mass.
2. Stong magnetic field shields to divert any charged particles away from
the ship.
3. Make the ship very long and thin, so there is not so much area for the
dust to strike.
4. Don't resist the particles; use them as fuel! Eg, fusion torch.
And thats only the ones I can think of right now. Any others, guys?
(snip)
> to cross. If there is no unknown technology {such as
> opening a temporary wormhole}, then we are left with
> two technologically daunting paths for crossing interstellar
> space: either 1) multigeneration ships far from any energy
> source, or 2) very high speeds, in which interstellar dust
> and gas would grind our ship to powder.
Whoa, whoa, whoa. Are we forgetting suspended animation here? It should
allow a slow ship (if a fast one is impossible to make) to use very lttle
energy on life support, and still deliver perfectly healthy young astronauts
to the stars.
Sure its not been shown to work yet, but neither do I see any generation
ships or even space vehicles capable of approaching 0.1 psol.
Up, up and atom!
LH
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