>So, I figure since a circle is two dimensions and you can travel in one dimension, and since spheres are three >dimensional and you can travel in 2 dimensions, the universe must be a four dimensional sphere.

That is, of course, only when you restrict yourself to the surface (or outline) of the circle or sphere. You could tunnel through the sphere. I could start in Chicago, IL and tunnel through the earth (ignoring the obvious heat and mechanical problems) and end up at Australia much faster than if I flew a plane over the surface. So, if you were to apply this to your theory of the universe, space travel to distant places might not be such a problem, if there was some way to "tunnel through" the universe instead of traveling along the outside. This is actually a kind-of feasable theory with worm-holes and all that fancy stuff. Um...er...I don't know exactly where I'm going with this, but you got my mind working a little, which is a good thing.

Char"now if only we could travel through a wormhole without being stretched into spaghetti and torn to shreds"on