Stanford Torus vs Bernal Sphere

From: Michael Capriola [mailto:capcartoonist@...]

>Adding up the figures, I find that most of the extra 3.467 Mt of
shield for
>the torus makes up the 3.09 Mt difference between the two habitats.
In
>everything else -- nitrogen, oxygen, structural mass -- the torus uses
less
>than the sphere.
>
>This is because the torus has more surface area that needs to be
shielded --
>2,127,701 m^2 compared to 1,367,784 m^2 for the torus.

"Combs, Mike" responded:
"That sounds right to me. I get the impression the calculator is making
a slightly bigger sphere than what O'Neill proposed. It could be that
he was assuming a slightly greater population density. I know he
compared it to some of the older parts of Europe."

The Space Settlements: Design Study book put optimum population density at
67m^2 per person. The belmont calculator had 68^2 per person for their
Torus of pop 10,000. So I plugged in smaller and smaller radii for the
Sphere until I came up with the 68^2 figure for 10,000 pop in a sphere.
Basically, I aimed for two habitat designs that shared as many features in
common as possible (same population and pop density, same energy usage, food
and water requirements, etc) in order to get a better idea on how the two
designs would differ.

If you want to increase population density, then both the sphere and the
torus can be smaller.
The problem here is that some arbitrary decisions are being made along the
way: people won't be happy above a certain popultion density, or people
won't be comfortable above N revolutions per minute, etc.

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