I can't say how it started, but I have a feeling(yeah, yell at me all you like, but I 'thorize', if that makes you feel better.) that the Universe is just a circle.(racetrack-y) With one start and no end. It begins, and keeps going around, with the beginning of another 'Universe' and the end of the previous one at the end of the lap. I believe that our 'Big Bang' was no more that a stupid civilization, like ours() accidentally opened a Singularity...or stupidly tried to make the wohole Universe travel through Time because the end was coming. The Singularity then got loaded with the Universe's mass, and collapsed, expannding infentisimally in the process...A new Universe began, conserving EVERYTHING that was there before.