Rotating space colonies

You have got to be kidding. Did you do any real research into this ?

"In my view, only the artist showed this in his presentation. Surely,
nobody ever calculated on what forces would be at work in such a giant
rotating structure? I haven't either, but by intuition as an engineer, I
say this cannot be done. Just imagine that a steel cylinder at say 500
meter in diameter (the assumed torus cross-section) at 1 bar
overpressure would need a wall thickness of around 10 inches (250 mm),
just to hold against air pressure against vacuum alone and without any
safety factors (then it would become thicker) - all around glass panels
to let in sunlight (what about green-house effect as well)?
Even if we assume a lighter construction of a multi-layered hull with
stiffening frameworks in between, when we bring the rotational forces of
the masses of the hull and its interior structures as shown into
account, I don't need to calculate any further - this is fiction only!
Also on Earth we could not construct column-shaped buildings of several
kilometers high - they would collapse under their own weight (this is
why the steel structure of the Eiffel tower in Paris has its funnel
shape - steel has far less compressive strength than concrete and bricks
and is four times more heavy)."

However I do find this relevant

"(when you've read this, you'll know what else to ignore on the subject)"**
**
yep I surely do.

by the way, your link to
http://www.nas.nasa.gov/About/Education/SpaceSettlement/index.html is
broken.

B

Niclas Jacobsz wrote: