When and how did the universe begin? What is the nature of reality? Is the apparent grand design of universe evidence of a creator who set things in motion - or does science offer another explanation? In this illustrated book, Stephen Hawking and Leonard Mlodinow present scientific thinking about these and other questionsd of the universe, in nontechnical language marked. The authors explain that peoloe are the product of quantum fluctuations in the early universe, and show how quantum theory predicts the 'multiverse'.