> >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.
>

That's a very good point. It applies to the circle as well as the sphere; why travel the circumference when you can traverse the diameter instead. You're not exceding the boundaries of your own dimension.
The forth dimension does exist and is commonly referred to as: time. It is a common connection to an object or event that gives a final dimension as to where it exists (or existed). One cannot refer to something without giving this final description in order to specify where it exists. The term "space-time" refers to this such connection and is truly fundamental to the nature of the universe.

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

Tra "you know, spaghetti sorta resembles worms; could that be from where the name derived?" nio