I like to discuss these concepts with my daughter Molly. She says it makes her head hurt

Are there multiple universes?. Scientific American is running this article about parallel universes. The article discusses four types of parallel universes that might exist. The author argues vigorously that the existence of these kinds of parallel universes are scientifically valid theories. This is, in my opinion, necessary because one can make a strong case that none of this is science but philosophical wanking. [kuro5hin.org]