Listening and walking

Yesterday and today I didn't listen to music as I walked, but instead I listened to a talk by theoretical physicist Brian Greene on his book, The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. I've actually checked out this book a few times from the library and each time the ideas have been so disturbing ;) that I've given up. I think multiple universe/parallel universe possibilities are so intriguing and attractive, but I have no science background and all my knowledge on the subject comes from science fiction. Maybe I'll give the book another try. Anyway, the talk was very interesting and for a while I was able to forget my knee hurt :) ....