The idea of multiple universes is well established science and from the moment I began to skim the surface of understanding my imagination ran wild. When you are told that, fact: a particle can be in two places at once and that nothing is real until it is observed you have the building blocks for a story with no limits.
If you want to get an easy(ish) insight into this strange world buy this great book: “In Search Of Schrodinger’s Cat” by John Gribbin, available on amazon.
http://www.amazon.co.uk/In-Search-Of-Schroding…/…/0552125555