Speaking of the Big Bang and expansion of the universe, according to a recent publication, there might not have been a Big Bang at all. If they turn out to be right, not only will we have established that the Universe didn't have a beginning but simply "always was", but we'll have solved the problems of dark mater and dark energy. And of course, this means the Universe won't have an "end" in the way we think of currently. Exciting stuff, if it can be verified. It would throw modern cosmology on its head, to say the least.
It would be the scientific equivalent of taking the world's largest file cabinet, opening all the drawers and turning it on its head, if it were to be verified. Infinites are a bit upsetting to think about, too, so I doubt it will be readily accepted. I was about to raise several objections when I saw this, before realizing none of those objections were valid.