Science fiction

Science fiction is a genre of fiction in which at least part of the narrative depends on the impact of science, either real or imagined, to generate settings or events which have not yet occurred in reality (and may never do so).

Robert A. Heinlein, a leading writer of science fiction, wrote "A handy short definition of almost all science fiction might read: realistic speculation about possible future events, based solidly on adequate knowledge of the real world, past and present, and on a thorough understanding of the nature and significance of the scientific method." [1] He immediately adds that if you "strike out the word 'future' it can apply to all and not just almost all SF."

SF author Theodore Sturgeon wrote "A good science fiction story is a story about human beings, with a human problem, and a human solution, that would not have happened at all without its science content." [2].

Of course, both of these authors are defining what they consider to be good science fiction. Not all writers or fans agree on how important realism and characterization are in science fiction. Any story, film, game, or toy that includes aliens, spaceships, time travel, or the future is called science fiction.