[Kamog]

To get around the problem with artificial gravity not being uniform inside a sphere world, maybe we could build the world so that it is not a solid one-piece sphere, but a combination of ring worlds stacked one on top of each other. So at the equator, you have a large diameter ring world, rotating to produce 1G of artificial gravity. Above and below this ring world, you have two more ring worlds of slightly smaller diameter, rotating at a different speed as to also produce 1G. Then, above and below those, have slightly smaller-diameter ring worlds rotating at its own speed to produce 1G, and so on. So the sphere world will consist of hundreds of ring worlds arranged in the shape of a sphere, with the largest ring at the equator and the smallest rings at the poles. The smallest rings will have to rotate the fastest to produce the same gravity. All the ring worlds could be enclosed in a larger, solid sphere so that it looks like a solid sphere world from the outside, but would consist of separate ring segments with independent rotations inside. Hmm, I guess this really isn't a sphere world...