For nearly 50 years, until his death in 1988, aged 70, Richard Feynman's discoveries lay at the heart of the development of modern physics. Always controversial, Feynman (whom a colleague described as being like a combination of Groucho Marx and Alfred Einstein) was a key physicist from his days as part of the atom-bomb-making team at Los Alamos in the early 1940s, until his discovery of the reason for the Challenger Space Shuttle disaster 40 years later. This book combines Feynman's life-story with an account of his thought and its context.