Posted by the World Science Festival, this presentation is part of The Big Idea Series, and I could not stop watching it once I started. From the Big Bang to the Multiverse, they explore a wide range of ideas, all theoretically supported to some greater or lesser extent, and some of them even have some experimental results that support the possibility that they exist. This is fascinating stuff, and the implications keep getting more numerous the longer you think about them. The original panel and gathering happened as part of the 2009 World Science Festival, and was posted in 2015; enjoy.