Has anyone heard of the theory about the Big Crunch? I believe it stated that the Universe will one day (eons from now) collapse and return to the state it was in before the Big Bang. Don't get me wrong, I don't believe in the Big Bang but I enjoy reading about it. So could some one help me out with some information? It would be greatly appriciated.

The related theories stated that at later stage of big bang, the universe will either

a)continues to expand forever
b)stop at a stable size
c)falls back onto itself (the crunch)

all depends on the total mass of the universe and velocity of the bang I suppose (and antimatter darkmatter blah blah).