3/7/08 - Grand Unified Theory, Stephen Hawking, and Sir Martin Rees

Segment 1: A discussion about theoretical physics with Harvard professor Lisa Randall. Her book is called ''Warped Passages: Unraveling the Mysteries of The Universe's Hidden Dimensions''. Segment 2: We conclude with Harvard biology professor Edward O. Wilson. His latest book is ''The Creation: An Appeal to Save Life on Earth''.