Artificial Biospheres In Space

--- In spacesettlers@yahoogroups.com, "victoriatangoman"
wrote:

> You would really profit from a review of the literature buried
> within the archives of this group and SSI.
>
> I recall that a number of group members were involved in the
> discussion. I followed the topic, but didn't participate in the
> dialogue.
>
> I've noticed that the search function now only searches the
> archives in tranches of 150+ messages rather than the entire
> archive as one search.

Whew! I had to search by hand, rougly 25 messages per screen, and
went through the 4000+ messages here and 5000+ at SSI. I found
where we'd discussed the window and mirror problems before, but
nothing much on a central axis illumination problem, other than

Discussion of internal diffuse reflection. SpaceSettlers #1174-
#1176, #715 at SSI.

Discussion of the intensity problem with axial light, where you
mention seeing some reports suggesting that the materials would
melt, and suggest possibly using a hot plasma instead.
SpaceSettlers #2824-#2825

Discussion of your mountain idea, #2236 and #2285.

Other than that I came up with nothing, unless the topic drifted to
the subject and the thread name bears no relation to it.

Also ignore my previous central cone idea. A pure cone is unlikely
to work right, since the narrow end has a very small circumpherence
and the far, fat end has a very large circumpherence. So at a
constant heat and light load, the station is dim under the narrow
end and of the cone and very bright under the fat end of the cone.
Using the outside surface of a paraboloid might solve this problem
(recalling that the actual reflecting surfaces are just grooves
machined at 45 degrees to the axis), but it still leaves you with no
way to make the sun move. There's also no good way to dim the
lights, so every evening Elvis would just leave the building.

I started looking at an alternate central axis method that would
basically be an inverse of a planet, with at any given instant
having half the station dark, and the rest illuminated much like a
normal day. I don't see a good geometric way to pull it off, and it
also requires whatever shap you use to rotate slightly out of sync
with the rest of the station (off by 1 rev/day), which means
bearings and gears. If I come up with any interesting way around
these massive drawbacks I'll post it.