how can the universe be expanding when it is infinite? If it is not infinite where does it stop?

There are ways of calculating the average mass and the size of the universe, but so far nobody there have been several flawless answers that don't agree with one another.

The answer is going to depend on what shape space is. Gravity is going to work differently in flat space, positively curved space, or negatively curved space. At the tiny, tiny, tiny level (say, a planet or moon), gravity is just going to pull you to the closest physical body. Even on the slightly larger level (a star and its planets), gravity is pretty constant. But when you start looking at the effect of galaxies on one another, and those wacky and inexplicable quasars way the hell out there, suddenly the principles of gravity that seem to simple are breaking apart!

So is it infinite? Go find an answer you like, and there's probably good evidence to support it. Does the universe stop? That's most likely true, but if you go to the edge of the universe, then the edge of the universe won't be at that point anymore. So again, find an answer you like and be happy with it, because nobody can prove you wrong!

The universe isn't infinite. That's how it can still be expanding. As for where it stops, that changes as it expands, everything is basically just guesswork as far as where the universe ends. I doubt we'll ever know the true size of the universe.

I guess when you consider that fact that the universe is everything (as far as we know), the thought that it might not be of infinite size can be a bit disturbing.

Firstly, Something infinite can expand.

Do your mathematics.

What's Infinite + 1 ? infinity.

what about Infinite +1000000000000000 ? infinity.

So infinte things can expand and grow to become infinite.

Wheather or not universe is infinite - depends on you defination. In case of space - i can say universe is infinite. Why? well anything you have is part of the universe.

Its "expanding" because light is going outward form the start of the big bang.

Light may start to "curve back" due to gravity - but most research indicates it will continue to go away from us and thus it will expand.

The problem in the question is the definition of 'infinite'. 'Infinity' is an undetermined quantity by definition of mathematicians. That means it is unkown. The only characteristic of the quantity infinity is that it is a very huge big number that is bigger than any number. Many times when comparing a very large number with a small one we can consider it an infinity for it. No one can say that he knows the volume of the universe or its dimensions, but the expansion of the universe is proved by scientific experiments and thus it is a fact. I think the universe is finite, but we can not realize it because it is so huge. I believe that this universe is not created by accident, there is a creator for it who knows where it stop and from where it started. Everything in this universe is moving in a very strict laws, it is not chaos or random.

Try thinking of what the words "universe" and "infinite" really mean --- everything there was, is, or ever will be. At this stage in mankind's accumulated knowledge base, asking what lies beyond our universe, or what existed before our universe, is a fascinating question but at the same time a futile one. If you stood at the North Pole and asked what's farther north, obviously you'd not get any answer that could be proven.

It is infinite. When people say its expanding, it means that THEY are finding new things out there that they hadn't seen before. But whatever those things are, they were always there and are always forming. There is a lot that we still don't know that exists out there.

it is "infinite" b/c no one can really measure it. the universe is also expanding so it's essentially growing but it will contract or you can look up string theory....that might help ya