Our universe may be one of many, physicists say. In fact, that's the most likely scenario.
The universe we live in may not be the only one out there. In fact, our universe could be just one of an infinite number of universes making up a "multiverse."
Though the concept may stretch credulity, there's good physics behind it. And there's not just one way to get to a multiverse — numerous physics theories independently point to such a conclusion. In fact, some experts think the existence of hidden universes is more likely than not.
Here are the five most plausible scientific theories suggesting we live in a multiverse:
For the rest of the story: http://www.space.com/18811-multiple-universes-5-theories.html