Stephen Hawking: Lifelong Quest to Unlock Cosmic Mysteries

British astrophysicist Stephen Hawking, who turns 71 has done a lot of thinking about the nature of the universe. The renowned scientist has lived most of his life with a paralyzing disease, but his undaunted efforts to unlock the secrets of the cosmos have revolutionized physics and captured the imagination of millions. VOA’s Rosanne Skirble looks at Stephen Hawking’s remarkable career.