What happened to live long & prosper?

Billboards that know a passerby's underwear size. (Hideous thought!) Vertical highways. Animated cereal boxes. For his new movie, "Minority Report," Steven Spielberg gathered together 28 futurists and asked them to dream up a vision of the world 50 years from now.

But while it is filled with nifty gadgets (I mean, who wouldn't want a jet pack?), this vision of the future is not a place where you'd let your children play outside. And that's despite a police state that's gone beyond even what George Orwell foretold. In an attempt to wipe out murder, the police arrest citizens for future crimes they may not yet have thought of committing. In the case of Tom Cruise, his character has never met the man he's supposed to murder.

It's a provocative premise: a Dystopia created from a Utopian ideal. That's not surprising, since it springs from the powerful imagination of sci-fi author Philip K. Dick, who inspired films like "Blade Runner" and "Total Recall" – neither of which was particularly cheerful.

So why, when we envision the future, is it usually a place in which no one would ever choose to live? ("Star Trek" and "Contact" being notable exceptions.)

In fact, sci-fi author Paul Levinson ("The Consciousness Plague") categorizes the landscape of current science fiction as "ranging from mixed to bleak to utterly catastrophic."

That's partly because two of the acknowledged classics of the genre, "1984" and "Brave New World" – out of which whole universes of literature have sprung – are grimly dystopic. And like Orwell and Aldous Huxley, Levinson says that thoughtful writers use futuristic novels as warnings against present-day evils, like the loss of privacy and the corporatization of, well, everything.

But cultural historian Tim Burke says you can also blame the Christian tradition of the apocalypse. The idea that things can not only go horribly wrong, but that someday it could be Game Over for everyone is a powerful fear that has been worked out in Western culture for centuries.

Plus, he points out, after the 20th century, the writings of Utopian futurists looked downright silly, as do those sci-fi movies that traffic in outlandish notions of happily ever after. (To bolster his point, he brings up "The Fifth Element" and "Demolition Man," starring Sylvester Stallone, which is kind of like swatting an ant with a howitzer.)

And although we humans have enjoyed several thousand years in which the world has not ended, somehow, the doomsayers have never been as thoroughly discredited as the dreamers. The bad stuff is just easier for us to believe, Burke says. Frankly, even Thomas More didn't have high hopes for the creation of a perfect society: "utopia" means "nowhere."

That's not to say that dark and depressing automatically equals deep, he adds. A lot of filmmakers use Dystopias as a kind of literary shorthand. A sterile steel landscape or blasted wasteland appears on screen, and the audience nods sagely and says as one, "Ah, it must be set in the future."

Case in point: This summer's "Reign of Fire" in which Matthew McConaughey slays dragons in a postapocalyptic world. And does anybody want to argue that "Waterworld" was an Important film?

Film professor Eric Faden sees another motive behind the effects-laden movies decrying the evils of technology. "Writers don't want to lose their jobs. So they write movies about how dangerous and bad technology is – even though an amazing amount of high technology is needed to create the message." (This is admittedly tangential to our line of discussion, but I'll write a mile out of my way to include cheap irony.)

Finally, as Milton famously discovered, it's just a lot harder to make goodness interesting. But Levinson, who is also a professor of communications and media at Fordham University in New York, doesn't think that's entirely a cop-out. "In the real world, goodness doesn't come down from the clouds like cotton candy." In fact, it's never achieved without a struggle.

The main difference in sci-fi thought today, he says, is between stories that believe in the struggle and those that hold that resistance is futile.

For all these reasons, it will be a while before you see a trailer for " 'Sirius 6: Oh, What a Wonderful World' – coming soon to a theater near you."