"Think Of The Universe Like A Deck Of Cards"

by Zoe Pollock

 Brian Greene instructs:

Now, if you shuffle that deck, there's just so many orderings that can happen. If you shuffle that deck enough times, the orders will have to repeat. Similarly, with an infinite universe and only a finite number of complexions of matter, the way in which matter arranges itself has to repeat.

Or put another way:

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.

You can listen to his full conversation with Terry Gross here and Leonard Lopate here.