I didn’t put this in GQ cos I don’t know if it can be definitely answered.
Is it possible that the universe is waaayyyyy bigger and older than we think? IIRC, the most distant objects we’ve seen are about 15 billion light years away. Who’s to say that, if you were to stand on the surface of a planet in one of those distant galaxies that the universe wouldn’t go on another 15 billion light years?
According to some theoretical cosmologists, no matter where in the universe you are, the farthest obejcts obeservable are some 15 billion light-years away. In other words, the universe has no center and no edge. Imagine standing on the surface of a ball. The universe is the surface of the ball, and nothing else exists. The fathest point from you ist he opposite side of the ball, and no matter where you are, that distance is always the same.
Cosmology isn’t always fun, but it’s always weird. I’m not suggesting the universe is ball-shaped. It’s only an example to illustrate the way one can look at it; that is, that there is no center and from any viewpoint in it, the universe looks identical.
The surface-of-the-balloon/ball analogy seems to be pretty popular, and it’s apt from what I understand. To avoid questions like Zunite’s, writers who use it always add “This isn’t literally true, and don’t try to picture it because your head will explode.” In so many words.
The whole surface of the ball thing is great. Thing is, I need a different analogy. I have been trying unsuccessfully to explain this to MsUnwrittenNocturne for a while. She says that it makes her head explode
Probably because she is having difficulty <i>not</i> envisaging the inside of the ball, and the outside. And the math is way to tough
OK, first get MsUnwrittenNocturne a good, stiff drink. Ready? Good. Alright, well instead of the surface of a ball, think of it as a videogame screen, where the characters can “wrap around” when they leave the edge of the screen and appear on the oppsite side. It’s topolgically identical to the ball-surface analogy, but a bit easier to visualize. Again, for purposes of this analogy, nothing else but the two-dimensional surface of the screen exists. In our universe, of course, we have three dimensions, but trying to visualize this including that third dimension is a bit much for our primitive brains, but if you can accept the two-dimensional analogy, you’ll at least have a rough handle on the concept.
The third dimension didn’t go anywhere, it’s being ignored for the sake of simplicity. It’s not present in the sphere analogy, either (recall that nothing exists but the surface itself, which is a two-dimensional surface curved in the third dimension, whereas real space is three-dimensional, curved through a fourth dimension). Think of the way in which cartographers represent the spheroid Earth on flat map projection, and you’ll have the general idea.