Robert Anson Heinlein (July 7, 1907 – May 8, 1988) was an American science fiction writer. Often called the "dean of science fiction writers", he was one of the most influential and controversial authors of the genre in his time. He set a standard for scientific and engineering plausibility, and helped to raise the genre's standards of literary quality. He was one of the first science fiction writers to break into mainstream magazines such as The Saturday Evening Post in the late 1940s. He was one of the best-selling science fiction novelists for many decades, and he, Isaac Asimov, and Arthur C. Clarke are often considered to be the "Big Three" of science fiction authors. A notable writer of science fiction short stories, Heinlein was one of a group of writers who came to prominence under the editorship of John W. Campbell, Jr. in his Astounding Science Fiction magazine—though Heinlein denied that Campbell influenced his writing to any great degree. Within the framework of his science fiction stories, Heinlein repeatedly addressed certain social themes: the importance of individual liberty and self-reliance, the obligation individuals owe to their societies, the influence of organized religion on culture and government, and the tendency of society to repress nonconformist thought. He also speculated on the influence of space travel on human cultural practices. Heinlein was named the first Science Fiction Writers Grand Master in 1974. He won Hugo Awards for four of his novels; in addition, fifty years after publication, three of his works were awarded "Retro Hugos"—awards given retrospectively for works that were published before the Hugo Awards came into existence. In his fiction, Heinlein coined words that have become part of the English language, including "grok" and "waldo", and popularized the terms "TANSTAAFL" and space marine. He also described a modern version of a waterbed in his novel The Door Into Summer, though he never patented or built one. Several of Heinlein's works have been adapted for film and television.