Stephen Hawking is a giant in the scientific world, despite the fact that Lou Gehrig's disease has severely disabled him, causing him to lose the use of his arms, legs and voice. Hawking is a cosmologist known for his simplified explanations of complicated scientific topics. Author Kitty Ferguson has a new biography out about him called, "Stephen Hawking: An Unfettered Mind" (Palgrave Macmillan/2012). Host Frank Stasio talks to her about her new book.