"Real" ringworlds

[Jack Simth]

Originally posted by Narrew:
I thought that Dyson Spheres were inhabited on the inside like a Ring World, but completely encompass the sun to trap all energy and possiably hide from the rest of the universe (wasnt it a Star Trek movie that found a bunch of Dyson Spheres?).

That was the original idea, but the mass of the Dyson Sphere is useless for producing gravity inside the sphere, as the gravitation produced by the mass "below" you is cancelled out exactly by the rest of the sphere (assuming an even distribution, that is) leaving only the mass of the star to pull on you - which means things tend to drop into the star if they aren't anchored down. Some form of artifical gravity, or anti-gravity would be required.
Likewise, the star isn't affected by the gravity of the sphere, and can wander around, probably impacting on the sphere's inner surface, unless some controlled force is applied.

In other words, to get a Dyson Sphere to work, you need artifical gravity and the ability to move stars around at will - in addition to the matter needed to build the sphere, the materials technology so that the sphere maintains its shape, and possibly a few other things.

If you plan on living on the outside, you can drop the artifical gravity, but not the rest.

[ May 14, 2003, 22:34: Message edited by: Jack Simth ]