I watch a fair amount of the science channel and I find it interesting that the universe is still expanding, but I don't buy into the theory that the universe will one day rip itself apart.
My own theory is this: It's been said there are more stars in the universe than grains of sand on every beach on Earth. Every star in the universe could potentially become a black hole, and those that don't, will end up being food for a black hole. Far into the future, black holes will outnumber stars and these extreme forces will be gobbling up everything, growing bigger and stronger. With all this, at some point, I think the universe will stop it's expansion and begin to shrink. Eventually, the black holes will consume each other until only one remains. At this point, with nothing left to feed on, I think that lone black hole will begin to shrink, feeding on itself until it can no longer contain itself and explode into Big Bang #2 (or maybe there's been more Big Bangs than that).
