Science fiction is a native 20th century art form that came of age at the same time as jazz. Like jazz, science fiction is very street-level, very American, rather sleazy, rather popular, with a long and somewhat recondite tradition. It's also impossible to avoid, no matter how hard you try.
Science fiction boasts an impressive predictive track record--if you squint hard and ignore most of the evidence. Atom bombs, spacecraft, comsats, credit cards, jukeboxes, waterbeds, gene splicing--they all appeared in science fiction first, well before showing up at the mall or on the military base. But science fiction is visionary by design and prophetic only by accident. You'll have a hard time finding androids, aliens, time travelers or psychic powers at the K-mart, even though science-fiction writers have obsessed about them for 70 years.
The U.S. Congress's Office of Technology Assessment had all the virtues sometimes claimed for science fiction. The OTA was concerned with genuine hard-core technological prediction. It paid close scholarly attention to technical trends and their social implications with facts, figures and footnotes--and Congress abolished it in the mid-1990s. The OTA didn't work out; science fiction suits us better. American society prefers having supergizmos dropped on its head out of nowhere, with no time to prepare and no real thought of the consequences. We love it that way. It's livelier, funnier, freer and just more American. "Leap, and the net will appear!"
If science fiction outlived the OTA, it also gets more girls, gold and glory than its other big rival, professional corporate futurology. Corporate trend spotting, after all, is limited to gizmos that might conceivably make someone money. Science fiction, in its sleep and entirely by accident, makes absurd amounts of money: SF films, comic books, action figures, CD-ROMs, computer games, chrome cards, costumes--there's no end to it.
Science fiction is a fun-house mirror for a society warped by raging technological advance. Science fiction doesn't want or need to make much sense. It seeks astonishment, terror, wonder, ecstasy and dread. It is spectacular and mythic, an oxygen tent for society's daydreams. Science fiction cordially ignores many vital technologies, such as, say, garbage recycling. Recycling is hugely important, but it has zero science-fictional thrill.
SF's saga of the techno-sublime is about power, speed and transcendence of human limits. Ray guns, starships, artificial intelligence, virtual reality, nanotechnology--all beloved of SF, and every last one of them a big Technicolor disruption of the mundane.
When science fiction gets over its trite romance with the parts catalog, it can achieve unnerving power. Aldous Huxley and George Orwell are the classic exemplars of that small, elite class of science-fiction writers who frighten and annoy science-fiction devotees. Huxley's Brave New World (1932) bursts with prescient speculation: "feelie" multimedia, Prozac-like "soma" tranquilizers, test-tube babies. Late in life Huxley became a psychedelics guru, seduced by the potent allure of brain chemistry.