Takes the reader on grand tour of cosmology-the study of the origin , structure, and continuing evolution of the universe-exploring its history, theories, new evidence and discoveries, and controversies; discusses the development of the big bang theory, which hold that the universe began in a giant explosion some ten billion years ago; modifications of the big bang theory such as the inflationary universe model, which holds that a kind of negative gravity operated in the infant universe; the discovery of huge amounts of invisible matter, called "dark matter"; new maps galaxy position and motions including the "Great Wall", instrumental techniques and the remarkable suggestion that a slightly different universe would not allow the existence of life.