Super-habitats

On 9/7/06, Darren wrote:
(...)
> Canberra is located in what passes for mountains here in Australia (our
> mountains would only pass as foothills in most places around 800 metres)
> there is snow on the hills around us and on rare occasions in Canberra
> itself. I take the family down to the snow (just a few hours away), it is a
> lot of fun, so I can see that people will want snow. However, the
> end-caps/side-wall/air-curtain (what is the right name? end-caps I suppose
> but they do not fully enclose) give you the chance for real extreme skiing,
> you could have almost vertical slope, say 80-85 degrees, this would not be
> snow (I dont think it would stick) at first but as you dropped down and the
> slope changed you would change over to snow. Up high, with an oxygen mask,
> coming out of a door in the side of the cliff and begin the long drop. If
> the radius is 2,500 Km and we assume that the air is too thin at 25 Km then
> you would still be under almost full gravity 99% so you would drop fast,
> then you would need a slow change of the slope and gradually you bring it to
> around 40 degrees and that would still be a good slope, by having the run
> curve you should be able to have a run of 100 Km, the biggest problem would
> be how strong your legs were, would you be able to take such a long run?
(...)

Actually I tend to think of the contention walls not as vertical
walls, but rather quarter-torus or half-torus walls. My intuition is
that shape would be more pressure friendly. Also, the half-torus wall
likely would minimize atmospheric leaking by naturally producing
inward wind currents at high altitudes. Of course this is all
intuitive and I would need calculations and simulations to check that.

Anyhow, quarter or half torus walls would have a gentle slope close to
ground level and get progressively more inclined with altitude.
Therefore there would be snow accumulation at some level.