Einstein said that the most incomprehensible thing about the universe is that it is comprehensible. But was he right? Can the quantum theory of fields and Einstein's general theory of relativity, the two most accurate and successful—if incompatible—theories in physics, be united in a single quantum theory of gravity? In 1994, Stephen Hawking and Roger Penrose met at Cambridge's Isaac Newton Institute for a series of lectures carrying on the decades-earlier debate framed by Einstein and Niels Bohr about the true nature of the universe. The result was this book, originally published in 1996 and updated in 2010, debating the spatial geometry of the universe, inflationary versus cyclic theories of the cosmos, and the black-hole information-loss paradox.
"A debate between Hawking and Penrose ... raises the reader's expectations of a lively interaction, and this is fully borne in the transcribed discussion.... Hawking's effervescent sense of humor frequently enlivens the text."—Times Higher Education