Isaac Asimov (c. January 2, 1920 – April 6, 1992) was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000 letters and postcards. His works have been published in all ten major categories of the Dewey Decimal System (Although his only work in the 100s -- which covers philosophy and psychology -- was a foreword for The Humanist Way).
Isaac Asimov is widely considered a master of hard science fiction and, along with Robert A. Heinlein and Arthur C. Clarke, he was considered one of the "Big Three" science fiction writers during his lifetime. Asimov's most famous work is the Foundation Series; his other major series are the Galactic Empire series and the Robot series, both of which he later tied into the same fictional universe as the Foundation Series to create a unified "future history" for his stories much like those pioneered by Robert A. Heinlein and previously produced by Cordwainer Smith and Poul Anderson. He wrote many short stories, among them "Nightfall", which in 1964 was voted by the Science Fiction Writers of America the best short science fiction story of all time. Asimov wrote the Lucky Starr series of juvenile science-fiction novels using the pen name Paul French.
The prolific Asimov also wrote mysteries and fantasy, as well as much non-fiction. Most of his popular science books explain scientific concepts in a historical way, going as far back as possible to a time when the science in question was at its simplest stage. He often provides nationalities, birth dates, and death dates for the scientists he mentions, as well as etymologies and pronunciation guides for technical terms. Examples include his Guide to Science, the three volume set Understanding Physics, Asimov's Chronology of Science and Discovery, as well as numerous works on astronomy, mathematics, the Bible, William Shakespeare's works and chemistry subjects.