This is the compelling, first-hand account of Alan Guth's paradigm-breaking discovery of the origins of the universe--and of his dramatic rise from young researcher to physics superstar. Guth's startling theory--widely regarded as one of the most important contributions to science during the twentieth century--states that the big bang was set into motion by a period of hyper-rapid "inflation," lasting only a billion-trillion-billionth of a second. The Inflationary Universe is the passionate story of one leading scientist's effort to look behind the cosmic veil and explain how the universe began.