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<DIV>In a message dated 12/16/2005 1:40:23 P.M. Eastern Standard Time,
wingcat@pacbell.net writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2>As to
Mike's idea of sunshade and oscillators - the problem is<BR>that constructing
things that large wouldn't be as quick as<BR>simply launching a rocket with
existing warheads to Venus.<BR>Although, even the combined power of every
nuclear weapon<BR>currently on Earth probably wouldn't be enough to
significantly<BR>alter Venus's spin anyway. (Or would
it?)</FONT></BLOCKQUOTE>
<DIV> It wouldn't. The combined power of every nuke ever
made by Humans is a fraction of a percent the energy of the asteroid that killed
the dinosaurs, and that rock was "only" several km in diameter max.</DIV>
<DIV> And I didn't say "oscillators." Rather, the immense
solar reflectors at Sol-Venus L4, L5, and maybe L2, pivot back and forth in
place, while holding their overall position relative to Venus. So the beam of
reflected sunlight from each reflector alternately hits or misses Venus. It'll
look odd, like a series of small suns lighting-up and going-off periodically,
while remaining almost stationary in the sky (Venus does rotate, albeit slowly).
But this is the best method I could think of for *simulating* an Earth-like
day-night cycle on Venus satisfactorily (I hope - Haven't run every sim yet!)
without hitting Venus with something *really big* to alter its spin or putting
lotsa huge rockets all around its equator.</DIV>
<DIV> And yes, launching a rocket (or a bunch of them) at
Venus would be fairly quick. But how quickly would these get the job we
want done (the important thing), and would this screw-up Venus worse, more
than it makes it more habitable.</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2><BR><BR>There's also the problem of making the radiator fins out
of<BR>something that can transfer heat well but also stand up to<BR>sulfuric
acid and intense weather. Glass is the usual container<BR>for sulfuric
acid in labs, but glass is often not the strongest<BR>structural
material. (And if you just have a glass coating, the<BR>weather could
crack it, letting the acid at what's underneath.)<BR>Remember also that a
lightweight substance would make the whole<BR>mission easier to perform -
easier to ship to Venus.</FONT></BLOCKQUOTE>
<DIV> Never said it would be easy. There should be
something that'll work. Buckytube (with a thin, acid-resistant coating if
necessary) would do for structure. Light and as strong as we're going to get
with materials we have now or may have available soon.</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2><BR><BR>There's also the problem of radiating heat in space: vacuum
makes<BR>a good insulator.</FONT></BLOCKQUOTE>
<DIV> Can't do anything about this. But future
spacecraft, with advanced power plants (nuclear, fusion, antimatter, etc) will
likely have to have huge radiator fins. And with the sunshade blocking all
sunlight to Venus, it should cool off *eventually* (Never said this would take
less than a current Human lifetime) anyway.</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2><BR><BR>A Venus-diameter sunshade at the Venus-Sun L1 point
would<BR>probably be easier to build - and therefore faster to get
into<BR>place. I wonder if this faster-ness would offset the
slower<BR>speed of removing Venus's heat. If the Sun were
completely<BR>blocked off, how long would it take Venus to radiate enough
heat<BR>that the atmospheric temperature would drop to something near<BR>Earth
normal? (Overlooking, for now, the problems of Venus's<BR>geology and
atmospheric composition and pressure, some of which<BR>problems look like they
might go away by themselves if the<BR>temperature were
reduced.)<BR></FONT></BLOCKQUOTE>
<DIV></DIV>
<DIV> Dunno. But if the sunshade is easy to produce and
emplace, the reflectors (which are structures not a lot more complicated)
shouldn't be much moreso. The radiator fins lowered into the atmosphere will
likely be the biggest challenge, admittedly. Hey, terraforming any planet will
not be a project for anyone who likes instant gratification easily!</DIV>
<DIV> </DIV>
<DIV>Mike</DIV></FONT></BODY></HTML>