Here, knock yourself out.
(Which, by the way, may be a very real possibility if you take these people seriously.
Which should explain a LOT. :))
But aren't multiple universes simply a theory, a fancy?
A theory, yes, but not really a simple fancy.
Here's what Aurelien Barrau, a particle physicist at CERN, has to say about it:
"The multiverse is no longer a model, it is a consequence of our models".
And it is to a parallel universe that Michio Kaku speculates humankind will migrate at the end of our earthly history.
Finally, here is a fabulously interesting (if not exactly brand new) documentary about it. Don't miss it.
(If you've watched it before, re-watch it.
Even if you don't believe in watches. :))