[LeGrande]

If the universe is expanding, what is it expanding into?

That is a fun question. The universe is curved, it is expanding into itself. Remember time and distance are variables. If you could travel in any direction out to the edge of the Universe, you will find yourself headed back here again.

[1rudeboy]

Ok, let's throw Euclidean space out the window. [there it goes]

Wouldn't your theory depend on whether space is positively or negatively curved?

[brytlea]

But you would be really tired by then.