Re: starship-design: Re: The Size of the Problem

["Kevin 'Tex' Houston" <hous0042@maroon.tc.umn.edu>]

Timothy van der Linden wrote:
> 
> Kevin Replied:
> 
> >> A few plausible ways around the problem (requiring extensions of
> >> physics, however) come to mind:
> >>
> >>      1. Find some process to make antimatter which does not ....
> >
> >My (limited) understanding is that unless Quarks are made up of even smaller
> >particles (hints of which have been bandied about) this is not possible.
> 
> Only 2 months ago I saw a report from I believe the Fermilab that they had
> some minor clues that quarks might have a substructure (it must be on the
> web somewhere).
> 
> However, why is a substructure necessary? It is already known that quarks
> can change flavour under influence of the weak force. Take for example:
> n -> p + e- where a down-quark is changed in an up-quark

                                             _
Okay, but how do you change a d quark into a d quark for example.  My (again, limited)
understanding was that not enough of the right type of quarks are in a sample
of matter to allow one to create a sample of anit-matter.  I would be happy to
learn that I am wrong on this.  what are the quark triplets needed for:

Protons
Electrons
Neutrons
Anti-Protons
Anti-Electrons
Anti-Neutrons

> 
> >> Let us call 293,156 Mw-yr 1 "USE."   Well, Ok.  But I do prefer round
> numbers.
> 
> This doesn't say 293,156 Mw PER year, but say TIMES year! (Joules instead of
> Watts) So instead of a lousy 9 square kilometers of solar panels you are
> talking about: 3600*24*365*9,807,191=3.1E14 m^2

Ooops, OK, I see it. still, the solution is workable.  The next paragraph 
you wrote shows that a (rough) doubling of reproduction time is all that 
is needed.


> That roughly means 48 weeks of robot creation. However, those robot should
> create their own power supplies, so that would mean they could use no more
> than about 100 to 400 Watt (pretty efficient machines!!)

The main jobs of the Robots would be gathering material, and putting pieces
together.  The job of converting raw material into refined stocks would be 
the job of a central machine, (which would be fed by several tens of m^2 of
solar panels.  This is why I think that there might be some lower limit to
the number of Robots needed to start a new colony

> 
> >Some general notes, I would suggest mercury as a better collection site, due to
> >its proximity to our star.
> 
> Unluckely mercury doesn't have a moon. While its gravity is about 2.2 moon
> gravities I wonder if our robots like the climate on the surface.

They could be constructed out of materials that could handle the heat load.


-- 
Kevin "Tex" Houston 	http://umn.edu/~hous0042/index.html