23 Feb '08 13:14>
Originally posted by AThousandYoungIt does not work for the real earth due to reasons already mentioned here by other folks:
But what if you bump it?
It has been suggested that gravity will naturally correct bumps.
The earth is not spherical, the gravity is not uniform, there are bumps(mountains and valleys), other forces acting on the ring such as wind, etc, etc..
HOWEVER, if the ring's diameter is not just slightlty greater than earth's (as in the original hyphotesis), but much greater, then the effects of these irregularities become more and more negligible as the ring's diamater increases. But as you minimize the problem of irregularities as you move the ring away from earth, the asymetrical gravitational pull of the moon would prevent the ring from staying concentric. You would need to assume the earth "moonless". But again, not the real world.