The Life of the Mind: Making The Theory of Everything

In an introduction to a first edition of Stephen Hawking’s groundbreaking popular science book A Brief History of Time, Carl Sagan tells a story about how he happened to wander into the ancient ceremony of the investiture of new fellows into the Royal Society. On that day, Sagan noticed in the front row a young man in a wheelchair very slowly signing his name in a book. “A book that bore on its earliest pages the signature of Isaac Newton.