User blog comment:Yankovic270/Alternate Universes: Do They Exist Or Not?/@comment-1943951-20100819170502

actually, the Many Worlds theory of quantum physics proposes that every time there is a probability of a quantum event occuring that's less than 100%, the universe splits in two, creating two universes, one in which the event occured, and one in which it didn't. if that's true there's probably millions upon billions of universes, many of which are almost identical.