One of the rarest birds in the lands of literature is the scientist who writes novels. In mainstream fiction, such a creature is almost unknown. As C.P. Snow observed in The Two Cultures and the Scientific Revolution (1959), modern civilization is split in two. The scientists go one way, the humanists another, and those who would travel with both (like Snow himself, a novel-writing scientist) court the condemnation of both.

But one courageous band of writers straddles the two cultures ineluctably, no matter what the training or allegiance of its members. Their patron saint is H.G. Wells, and their craft is science fiction, the fiction of science.

Some few writers of science fiction are bona fide men or women of science, such as the biochemist Isaac Asimov, the astronomers Fred Hoyle and Carl Sagan, the physicists Gregory Benford and David Brin, or the experimental psychologist Alice B. Sheldon (better known by her pseudonym of James Tiptree, Jr.). Many others have no special competence in science at all, or, in curious deference to C.P. Snow's thesis, may even be hostile to the scientific world-view. But they share with their scientist-colleagues a fascination, almost an obsession, with the powers of science.