From: Eugen Leitl (eugen@leitl.org)
Date: Wed Jan 08 2003 - 13:26:04 MST
On Wed, 8 Jan 2003, Robert J. Bradbury wrote:
> Well, you still need some trace metals, and these are mostly going to
> be found in the inner solar system.
I don't know which purpose we're talking about here, but nanotechnology
and biology needs only traces of the heavier elements. Nanotechnology will
be very happy with carbon mostly. Hydrogen/Deuterium/Lithium is fuel/fuel
precursor.
> > Hydrogen to burn, water to drink, carbon for structures and
> > organics.
>
> Not so fast Harvey -- you can't burn the hydrogen unless you can
> split it from the water. That requires energy and you don't have
> much have that (at least the solar variant) in the Kuiper belt.
I think we can focus energy (beamed microwaves from the inner solar system
orbiting machinery) towards selected habitats to propel and/or power them.
Or spin up material from the deep orbits.
> So while I agree with much of the rest of your comment, I don't
> think we will see Kuiper belt colonization until we have "real"
> fusion reactors. That gets "iffy" because current reactor designs
Nanotechnology and lots of hard vacuum and microgravity along with
cryogenic temperatures (for cryomagnets?) seems to help a lot with
building reactors.
> I believe call for lithium blankets to capture the heat from the neutrons
> and lithium is a rare element, perhaps even more so in the Kuiper belt.
Li abundances:
Abundance ppb by weight ppb by atoms
Universe 6 1
Sun 0.06 0.01
Meteorite (carbonaceous) 1700 4600
Crustal rocks 17000 50000
Sea water 180 160
Stream 3000 430
Human 30 27
Doesn't look too shabby. Li burns too easily in stars, not in fusion
reactors. So there will be very little lossage of it, to breed tritium.
> (Lithium abundance in the sun is similar to that of Selenium or Strontium
> so it isn't a particularly common element). Alternate fusion cycles
> require the use of Helium-3 and that requires setting up mining operations
> on either the surface of the moon or the atmosphere of Jupiter.
>
> So, the plutinos are off-limits until you can get fusion reactor
> technology to the level that its "affordable" by a small group
> of people (at least IMO). [Spike may chime in here about building
> huge solar collecting arrays out of very thin material -- but to
> the best of my knowledge you need either metals (Al, Au, etc.)
> or perhaps Be to reflect light or IR. Those are also likely to
> be in short supply in the Kuiper belt.]
Light elements are fuel. There's no point in using all of them
immediately. For that small fraction of them which will be used there is
enough heavier elements.
This archive was generated by hypermail 2.1.5 : Wed Jan 15 2003 - 17:35:50 MST