Guest: Paul Dickson.

On October 4, 1957, the Soviet Union launched what would be the first man-made object to enter space. Today on Focus, we'll explore the dramatic history of Sputnik's launch, the instantaneous impact it made on the next decade to come, and the developments that brought America into the space race. Our guest will be writer Paul Dickson, author of Sputnik: The Shock of the Century.

Guest: Simon Singh.

The Big Bang model of the universe offers an elegant explanation of everything we see in the night sky, making it one of the greatest achievements of the human intellect and spirit. Even more wonderful, says science writer Simon Singh, it can be understood by everyone. Join us today on Focus as we talk with Singh about how scientist arrived at this remarkable theory.