'Within string theory, the strings that we're talking about are not the only entities that this theory allows. 'There are a couple of multiverses that come out of our study of string theory,' Greene says. So what does this have to do with the possibility that a multiverse exists? If it exists, it could explain literally everything in the universe - from subatomic particles to the laws of speed and gravity. It posits that the entire universe can be explained in terms of really, really small strings that vibrate in 10 or 11 dimensions - meaning dimensions we can't see. String theory smooths out the mathematical inconsistencies that currently exist between quantum mechanics and the theory of relativity. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos Recent discoveries in physics and astronomy, he says, point to the idea that our universe may be one of many universes populating a grander multiverse. Greene, the author of The Elegant Universe and The Fabric of the Cosmos, tackles the existence of multiple universes in his latest book, The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. Similarly, with an infinite universe and only a finite number of complexions of matter, the way in which matter arranges itself has to repeat.' 'If you shuffle that deck enough times, the orders will have to repeat. 'Now, if you shuffle that deck, there's just so many orderings that can happen,' Greene says. Think of the universe like a deck of cards. So if the universe is infinitely large, it is also home to infinite parallel universes. Eventually, matter has to repeat itself and arrange itself in similar ways.

Or it might be infinitely big.īoth 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. Our universe might be really, really big - but finite. The supermassive black hole at the center of our galaxy.

The Elegant Universe by Brian Greene