The cliche “to wrap one’s brain around it” is hereby retired, following its overuse in this thread. 
I remember an analogy that was used in a similar thread as this, regarding the question of ‘where is the universe expanding into?’. Someone answered that that question would be the same as asking what ‘time’ is expanding into. It’s not expanding into anything. The next hour or minute isn’t waiting anywhere for time to expand into it. Still the time does go forward. Hope this helps.
Her name is Shannon. I broke up with her years ago. I’m pretty sure she is in South Jersey now.
From The Elegant Universe, p. 346:
So, the location of the big bang is everywhere at the same time! No matter which direction we choose to look, we are by definition looking toward the big bang (and away from it at the same time).
Every point in the universe is the location of the big bang. I find that incredibly fascinating.
In both cases, if the universe is infinite in size and if it wraps around, “center” has no meaning. However, all that is just theory because we cannot observe that far. If you want to talk about the observable universe, we are the center. Or rather, you are. 
I thought it was in your local teen/twenty year old: your Eminems and Britneys.
(puberty now takes two decades instead of one)
Obviously, if things fall apart, the center can’t hold.
As a bit of a nitpick, the answer to this one is actually “no”. While it is still consistent with the data to suppose that the Universe is finite in much the same manner as an Asteroids screen, we do at least have evidence that if this is so, then the “screen” is much larger than we will ever be able to see. So unfortunately we won’t ever be able to see our own Galaxy “wrapped around”.
Incidentally, the ballon analogy is a bit unfortunate, in that it suggests that the geometry of the Universe is spherical. This is a possibility, but it’s also possible that the Universe is flat or hyperbolic (saddle-shaped, if you embedded it in a higher-dimensional space). In any of these cases, the Hubble Law is still consistent, and from any point in the Universe, you’ll observe other points as receeding uniformly from you at a speed proportional to their distance.
Jason:
Thanks. Your post rocked.
Ok, just to be sure I got this:
Another possibility is that the universe could be infinite and not closed: matter could continually expand into an infinite 3D space. Just as any 3 points on a plane define the entire plane (including areas outside the triangle formed by the 3 points), so there could be well-defined space in places where big-bang flung matter has not reached.
That, in turn, would imply either that the 3-space existed before/simultaneously with the big bang (although I speculate that “before” might be ruled out if we take the idea of an initial singularity seriously), or the infinite 3-space was created by/during the big-bang itself.
Chronos: Thanks for elaborating on the saddle-shaped part.
Wait a second. How could the “screen” be so large as to not allow light from the furthest galaxy unless matter is traveling faster than the speed of light (which isn’t permitted by relativity)?
Or is it that galaxies on the edge of the “screen” are too dim to be seen by even a planet-sized telescope (or something along those lines)?
(Furthermore, I would think that we might be able to see a very distant galaxy from 2 different sides, if we were able to see to the “edge” of the “screen”, but not much further.)
I think the fundamental mental block is that “the universe” is synonymous with “matter”. The “size” of the universe (measured as, say, the length of the maximal geodesically embedded circle) can and did increase faster than the speed of light, but in any given local neighborhood there were no violations of causality (no information transmitted faster than c). I really think the only way to really understand this better would be to actually study GR. I suggest the Phone Book, though you might need some mathematical background.
In the balloon analogy, the surface of the balloon represents space. It serves to show that space is expanding in all directions. As a result, the objects in it are redshifted because the space between us and everything else is getting bigger. The paper “dots” on the balloon represent gravity wells of galaxies and other large celestial objects. They don’t dissipate as space grows.
So, there isn’t a predetermined size of space in which things are zooming away from each other and collecting on the edges. Space is growing between everything in the universe as we speak. Theoretically, when the temperature of space reaches absolute zero, the expansion will stop as no movement, even at the atomic level, is possible at that temperature. The question then is whether the universe will be stabilized or experience a “big crunch” (fall back in on itself for lack of momentum).
I have no difficulties with the diameter of the universe’s matter increasing above the speed of light. I just don’t see how the radius of the universe’s matter could expand beyond the speed of light, absent a) the constituent particles moving past light-speed or b) some bizarre n-space that I haven’t thought about.
Perhaps. (But the book you linked to is 1300 pages and $120. Yikes!)
I once read that if you have problems conceptualizing an expanding universe, think instead of everything in the universe shrinking. Not the boundaries, mind you, just everything in it.
I’m sure the analogy isn’t perfect, but can some of the more enlightened folks tell me why this would be a bad way to envision the universe?
I’m sure someone will correct me if I’m wrong, but it is my understanding that the matter would move with space as it expanded. Matter would not be moving through space at all, but that space itself would expand at greater than the speed of light and carry whatever matter it contained along for the ride. As far as I can see, this wouldn’t break any laws of physics.
How can there possibly be a factual answer to the O.P.? 
The very first response basically said that there the question is ill-founded, and the rest of the discussion is just hashing out the details.
You did read the thread, didn’t you?
No, not if you’re talking about expanding into empty space.
We can’t talk about the instant of the BB, since everything is infinite at that time. (I’m talking about normal BB, not ultra-speculative string or M theory based junk.) So let’s talk about a tiny fraction of a second after the BB.
Open universe: Space is infinite, and all of it is filled with hot matter. There is no empty space anywhere. Space itself is expanding and so the hot matter is rapidly getting less dense and cooler.
Closed universe: Space is finite, and all of it is filled with hot matter, blah, blah blah. Since space is finite, if you had a long enough stick you could poke it forward and it would hit you in the back of the head. (Well, not really because you and the stick would boil away into constituent particles.) We can call the length of the stick you need the “circumference of the universe”. As time goes by, the circumference rapidly increases.
In either case, the hot matter eventually cools enough to form stars, galaxies, etc. Galaxies are held together by gravity, so they don’t expand as space expands. The distance between galaxies continues to grow. The very thin matter distributed in this intergalactic space is still growing less and less dense. This is what we call “space”. But nowhere is there pure empty space, where matter has not yet reached.
Very minor nitpick: Just to confuse things, there are a small number of galaxies in the Local Group of which the Milky Way (our galaxy) is a member that are approaching us rather than receding. It’s because the members of the Local Group are gravitationally bound to one another and by sheer random chance some objects are vectored enough toward us to counter the expansion of space. Those are the exceptions, though.
(This from Coming of Age in the Milky Way by Timothy Ferris, which I heartily commend to anyone interested in the subject of cosmology. A very good survey for the lay reader.)
Wait a minute. I thought that open and closed universes had to do with whether or not there was enough mass for it to eventually slow down its expansion and collapse (open = no, closed = yes). And that the concept of whether or not space is finite or inifinite was unrelated to this question.
I’m stating my understanding rather than stating a fact. Can someone clarify this please?
As an aside, I cannot understand how the universe could be infinite. After the Big Bang all space and time expanded and continues to expand. Doesn’t this mean that it has to be finite? (Unless one says that an Asteroids-like universe that wraps back upon itself is the definition of infinite of course.)