Professor of Astronomy at the University of Sussex, John D. Barrow's principal research interest is the early history of the universe. He is well known for his bestselling popular science books including Theories of Everything, Pi in the Sky, and The Artful Universe (OUP, 1995). Frank J. Tipler Professor of Mathematical Physics at Tulane University, New Orleans. He is the author of The Physics of Immortality: Modern Cosmology, God and the Resurrection of the Dead, Macmillan, 1995, £20, in which he presents a scientific proof of the existence of God.