In a new book, mathematician and theoretical physicist Brian Greene explains the concept of multiverses, and why some physicists believe there could be more than one universe. Plus, a look at the hidden universe of Greene's desk, this week's "Desktop Diary" video pick. Read more
Is it preposterous to consider the existence of parallel universes? Or is it preposterous not to? Physicist Brian Greene would tend toward the latter view. The Columbia University theoretical physicist's latest book, "The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos," follows up on his two earlier books for popular audiences, "The Elegant Universe" and "The Fabric of the Cosmos." Read more
A Physicist Explains Why Parallel Universes May Exist
Our universe might be really, really big - but finite. Or it might be infinitely big. Both cases, says physicist Brian Greene, are possibilities, but if the latter is true, so is another posit: there are only so many ways matter can arrange itself within that infinite universe. Eventually matter has to repeat itself and arrange itself in similar ways. So if the universe is infinitely large, it is also home to infinite parallel universes. Read more
Brian Greene on 'Icarus at the Edge of Time' Greene's "Icarus at the Edge of Time" is a charming children's board book that includes priceless photos from the Hubble Telescope. It recasts the Icarus myth into the Space Age, with the titular protagonist yearning to spread his wings while trapped aboard a generational ship searching for life on a distant planet.
I have a long-percolating post that I hope to finish soon (when everything else is finished!) on Why String Theory Must Be Right. Not because it actually must be right, of course; its an hypothesis that will ultimately have to be tested against data. But there are very good reasons to think that something like string theory is going to be part of the ultimate understanding of quantum gravity, and it would be nice if more people knew what those reasons were.