You know, I'm not sure. I know that there is scientific research being done and there are theories that suggest that parallel universes do exist. I believe the quantum theory suggests that there could be many universes where we already exist in a different environment, for example.
Recently, I read an interesting article on Wikipedia. Here's the link to that, if anyone's interested.
http://en.wikipedia.org/wiki/Multiverse It kind of gives you some broad knowledge about where the theory originally came from and how today's scientists are viewing that theory.
I found it interesting to imagine that I could be in several places at once without realizing it...