Isaac Asimov, 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 about 500 books and over 9,000 letters and postcards. His works have been published in nine of the ten major categories of the Dewey Decimal System (the sole exception being the 100s: philosophy and psychology). Isaac Asimov is widely considered a master of the science-fiction genre and, along with Robert A