[neutralino]

Kaley,

It seems you are confusing the notion of universe with that of observable universe. This isn't surprising, since I think most cosmologists uses the former term when sometimes they mean the latter, and vice versa (and I'm sure I've been guilty of doing so above!) To clarify, the observable universe is everything we can possibly observe today; it is a finite subset of space, and is usually thought of as a sphere centred on ourselves. Now, there is no reason to think that the observable universe is the entire universe. In fact, if it were, then it would be pretty weird since we would be sat at the centre of the universe (disobeying the cosmological principle). Thus, the entire universe is a lot bigger than the observable universe and could even be infinite (so there's nothing wrong with your use of infinity!)

However, the important thing to notice is that every point in space has its own observable universe at each point in time; a finite sphere centred on that point. Thus, the event horizon at the "edge" of each observable universe is not a physical boundary in the sense that we walk up to it and encounter a wall, it is simply a boundary past which we cannot see from the centre of the observable universe.

Again, I hope that makes sense. Also, note that I corrected a sentence in my previous post regarding boundaries as it was potentially misleading.