Science fiction (often referred to as either Sci-Fi or SF) 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." Science Fiction: Its Nature, Faults and Virtues in The Science Fiction Novel: Imagination and Social Criticism, Advent: Publishers, 1959. (This is a collection of lectures by Heinlein, Cyril Kornbluth, Alfred Bester, and Robert Bloch given at the U of Chicago in 1957). He immediately adds that if you "strike out the word 'future' it can apply to all and not just almost all SF."
Science fiction 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." quoted in James Blish, More Issues at Hand: Critical Studies in Contemporary Science Fiction (Advent Publishers, 1970) ISBN 091168218X.
More on [ Science fiction ]

Constructing an SF Universe - Excellent article by professional, published science fiction author, S. Andrew Swann.
Planetary Fact Sheets - Extensive physical data describing the planets, satellites, and comets of our solar system, courtesy of NASA's National Space Science Data Center. Potentially useful to designers of science fiction settings and the detail-minded.
| Halo: Combat Evolved Playthrough [Part 1] | |
| Next Video | |