well, out universe migh tjust kinda die. of course, we could be stuck in a kind of loop. the cycle would be this: the universe starts out infinitely dense, a single singularity floating around in space, eventually, it explodes, scattering matter everywhere, the matter keeps moving outward. however, its all trying to pull back together, and it does, and we end up with a new singularity. of course, the universe could just keep expanding. in that case, the universe would just die. it would keep moving, but all the stars would cool or collapse, all the planets would cool, and eventually the universe would be a cold dead place.