Little particles come into and out of existence all the time. It's even rarer for entire atoms to come into existence. The larger(right?) the thing, the less likely it is to come into existence(I think..). In an infinite amount of time, everything(literally) will have come into existence and infinite amount of times every infinitely small fraction of time. I always thought the bing bang came out from this.. Edit: In an infinite amount of time, everything will come into existence an infinite amount of times. Not every infinitely small fraction of time, that only happens if the universe is infinitely large, also.