GrahamS, mobius strips are too easy, check out a klein bottle.
Seriously though – it is impossible for the universe to go on for infinity, just as it is impossible for it to stop as surely there has to be ‘something’.
And if it does stop and there is absolutely nothing on the other side, a sense of being absolutely nothing, how can the universe expand into it?
And another thing – how can we use biiiiiiiig binoculars and see back in time to the big bang?
The universe currently has a finite size, which is fairly simple to work out, although you do have to make a few assumptions. Assumptions withholding, the universe will never reach infinite size. Stuff in reality doesn’t tend to reach infinite anything, as it’s more a mathematical concept. Reality has physical limits.
If there is nothing on the other side, surely it should be easy for the universe to expand into it. Much harder if there was something, surely? Really though, who knows. Go get a degree in astrophysics and come back and tell me.
The whole looking back in time thing only works if you can move faster then the speed of light. We can’t do this normally, so how about we assume we can use worm holes or something to move huge distances very quickly. So you move out 100 lightyears away from earth, in the space of a few seconds. You then get a mega powerful telescope, and look back at earth. The light that has left earth 100 years ago is just reaching you now. So you can see, with a birds eye view, what happened 100 years ago. Simples.