Last Monday, I heard Brian Greene talk at the Tattered Cover in lower downtown Denver as part of his tour promoting his new book “The Hidden Reality.” About 250 people turned out to hear him and about 100 people, including me, lined up to have him sign our copies of his book.
Brian mainly talked about three of various parallel universe, or multiverse, themes that are being considered today. In his book he goes into more detail discussing nine of them. One multiverse idea is essentially that if you go far enough in the space and time of our universe, things start to repeat. With a finite number of particles, there is a finite number of ways of arranging them. Brian used the analogy of a deck of cards. If you shuffle them enough time, the order of the cards will begin to repeat. If we go far enough in our universe we may come across me writing a blog about something else, or maybe one in which I don’t like the book. Brian also talked about another multiverses theme where individual universes could be thought of as bubble universes and yet another where universes occupy branes, like massive rubber sheets, that hover millimeters away from each other. It sounds like he favors this latter.
I’ve had his book on my shelf since it came out but haven’t yet had the chance to read it. I’ll write more about it after I’ve read it. His talk was a good introduction to the book, got us excited about reading it, and I’ve moved it up on my reading list. In the meantime, you might enjoy these videos (four parts) about multiverses. (Part 1 - http://tinyurl.com/2gx8yar; Part 2 - http://tinyurl.com/4r6wuwy; Part 3 - http://tinyurl.com/4h4unf7; Part 4 - http://tinyurl.com/4zxenav)