redesign of ONeill cylinder mirrors

From: Ian Woollard [mailto:ian.woollard@...m]

> Actually it does cancel if you counter-rotate it at the
> *right* speed, which is not necessarily the *same* speed.

True. I didn't give much consideration to that aspect because I was
thinking that a design goal here was to have stationary mirrors. In
this case the mirrors would be rotating far faster than the rest of the
habitat, and all the objections to the O'Neill Cylinder mirror design
become stronger.

> Actually, that's kinda interesting- the centrifugal
> force is a square law on 'w', whereas w is inversely
> proportional to I, so if you can use heavy rock for
> radiation shielding to cancel the angular momentum,
> you don't need much strength to stop the slower/heavier
> moving radiation shielding from flying apart.

I think that's the assumption of the Bernal Sphere, and one of its
advantages.

For example, if the shield is 10x the mass of the rest of the habitat
sphere (I think 10x is right for the Stanford Torus; might be slightly
different for Bernal Sphere), then it would counter-rotate at only 1/5
RPM. And no part of it would experience more than 1/10 G centrifugal
force.

Regards,

Mike Combs