Isaac Asimov was born in the Soviet Union, in Petrovichi, on January 2, 1920. When he was three, his family emigrated and settled in Brooklyn, where they operated a series of candy stores. An early and voracious reader, Asimov advanced rapidly through the public school system and completed junior high school at age eleven and high school at fifteen. During this period he discovered science fiction and became an ardent fan as well as an aspiring writer. His first story came out when he was eighteen and others followed steadily. "Nightfall," the most frequently anthologized science-fiction story ever, was published when Asimov was twenty-one.

At Columbia University, Asimov began to drift away from medical studies in favor of chemistry. (His distaste for zoology intensified when one assignment required him to capture, chloroform, and dissect a stray cat—something that Asimov says he still regrets having...