Along with Caltech physicist Mlodinow (The drunkard's walk), University of Cambridge cosmologist Hawking (A brief history of time) mixes cutting-edge physics to answer three key questions (Why is there something rather than nothing? Why do we exist? Why this particular set of laws and not some other?) and explains that scientists are approaching what is called "M-theory," a collection of overlapping theories (including string theory) that fill in many (but not all) the blank spots in quantum physics.

Originally published in hardcover: [New York] : Bantam Books, 2010. Includes index.

The mystery of being -- The rule of law -- What is reality? -- Alternative histories -- The theory of everything -- Choosing our universe -- The apparent miracle -- The grand design.