Tales from the multiverse. AFP publishes a story about the theoretical possibilities of so-called parallel universes:
"The idea of multiple universes is more than a fantastic invention — it appears naturally within several scientific theories, and deserves to be taken seriously," said Aurelien Barrau, a French particle physicist at the European Organization for Nuclear Research (CERN), hardly a hotbed of flaky science.
"The multiverse is no longer a model, it is a consequence of our models," explained Barrau, who recently published an essay for CERN defending the concept.
There are several competing and overlapping theories about parallel universes, but the most basic is based on the simple, if mind-boggling, idea that if the universe is infinite then logically everything that could possible occur has happened or will happen.
Try this on for size: a copy of you living on a planet and in a solar system like ours is reading these words just as you are. Your lives have been carbon copies up to now, but maybe he or she will keep reading even if you don't, says Max Tegmark, a cosmologist at MIT in Boston, Massachusetts.
The existence of such a doppleganger "does not even assume speculative modern physics, merely that space is infinite and rather uniformly filled with matter as indicated by recent astronomical observations," Tegmark concluded in a study of parallel universes published by Cambridge University.
"Your alter ego is simply a prediction of the so-called concordance model of cosmology," he said.
They tie it in to The Golden Compass, but the concept has been around for years in science fiction and fantasy writing. Robert Heinlein wrote a lot of his later stuff about that exact concept. So have a lot of others. (I can't remember off the top of my head who wrote the science fiction short story about a man going for a walk in the fog and losing his place in the multiverse. The idea that a light shining through fog represented the multitude of possible universes has stuck with me even if the name of the author escapes me at the moment. Was it Larry Niven?) These articles pop up now and again in the media, by the way. Search "parallel universe" on Google. Here's one example from 2003.