Dr. Paul Halpern on The Edge of the Universe

Paul Halpern is Professor of Physics at the University of the Sciences and an acclaimed science writer.  The author of 13 popular science books, most recently "Edge of the Universe:  A Voyage to the Cosmic Horizon and Beyond," he is the recipient of a Fulbright Award, a Guggenheim Fellowship, and an Athenaeum Literary Award.  Library Journal named his book, "Collider", its physics selection for the best science books of 2009.  He has appeared on numerous radio and television shows, including the Simpsons 20th anniversary special.