Stephen Hawking: Asking big questions about the universe

Stephen Hawking's scientific investigations have shed light on the origins of the cosmos, the nature of time and the ultimate fate of universe. His bestselling books for a general audience have given an appreciation of physics to millions. In this video, professor Hawking asks some Big Questions about our universe -- How did the universe begin? How did life begin? Are we alone? -- and discusses how we might go about answering them.