Penrose has given this Before the Big Bang talk repeatedly over several years and it has developed. Some new thoughts, new cartoon drawings. Here on YouTube is a version he gave 31 October 2007 at George Mason University (Fairfax, Virginia, near Washington DC). It comes in several segments. The first ones are his talk and the last ones are devoted to responding to questions from the audience. http://www.youtube.com/watch?v=0upkexD9Tf8&feature=related http://www.youtube.com/watch?v=c-q3XMpbQ98&feature=related http://www.youtube.com/watch?v=CzaIFmO2qz0&feature=related http://www.youtube.com/watch?v=unpZMWq_s_0&feature=related http://www.youtube.com/watch?v=3ReCsncYzB8&feature=related http://www.youtube.com/watch?v=Rd4-X9zjKfE&feature=related http://www.youtube.com/watch?v=8KcLkMpKL1E&feature=related I should also get the link to the version of the talk he gave at Perimeter Institute. Here is the Perimeter version given 12 September 2006, more than a year earlier http://pirsa.org/06090005/ Before the Big Bang: an Outrageous Solution to a Profound Cosmological Puzzle Roger Penrose - University of Oxford In some sense, other things being equal, LATER IS BETTER. However I have watched the November 2005 version given at Cambridge, perhaps the earliest version online, and like it very much. Although only voice+slides, not full video, the delivery is very clear. Does anyone have another version of this talk that is online? I'd prefer this to the popular media treatment of his ideas, and how they come across in an interview for general audience, because there too much gets garbled or diluted. I prefer to hear Penrose himself giving the whole Before the Big Bang talk with his own slides, where it is aimed at a smaller audience.