"THE GREATEST human significance of science fiction may be as thought experiments, as attempt to minimize future shock, as contemplations of alternative destinies," Carl Sagan wrote in The New York Times Magazine in 1978. "This is part of the reason that science fiction has so wide an appeal among young people: It is they who will live in the future. No society on earth today is well adapted to the earth of 100 or 200 years from now (if we are wise enough or lucky enough to survive that long). We desperately need an exploration of alternative futures, both experimental and conceptual."

Sagan's Times piece—"Growing Up with Science Fiction," about how reading pulp fiction led him to a career as one of history's great scientists—is as nitpicky as it is euphoric, taking pains to point out how unlikely it is that mankind will ever face that '50s staple of giant bug invaders ("Since insects and arachnids breathe by diffusion, such marauders would asphyxiate before they could savage their first metropolis") and how it's even more unlikely we'll ever meet a half-human, half-Vulcan like Mr. Spock ("such a cross is about as likely as the successful mating of a man and a petunia"). But even as he mocks the dull-witted scientists of Douglas Trumbull's 1972 space-hippie saga Silent Running (or damns the film with the faint praise of being "technically proficient"), Sagan finds purpose in even the goofiest of sci-fi: Of all genres, it might be the one that most directly impacts our creation and understanding of the future.

Silent Running will never look more technically proficient than on Thursday, April 16, when it'll screen as part of OMSI's Sci-Fi Film Fest, a collection of 14 films playing at the museum's recently renovated Empirical Theater. Not only does the Empirical offer one of the biggest screens in Portland, but the sound is there to match; there are few better places to witness some of Hollywood's contemplations of alternative destinies.

Top among OMSI's selections—for me, at least—might be Alfonso Cuarón's melancholy, still-astounding Children of Men (2006, screening Sat April 18), a near-future thriller set in a world without children. Along those same dystopic lines is another oft-overlooked, relatively modern classic: Terry Gilliam's 1995 psych-out 12 Monkeys (Fri April 17), with a glowering Bruce Willis and a wall-eyed Brad Pitt.

Older classics are well represented, too: There's 1956's Forbidden Planet (Mon April 13 & Sun April 19), a take on The Tempest that improves on Shakespeare by adding Robby the Robot, and 1951's The Day the Earth Stood Still (Tues April 14 & Sat April 18), its warning about mankind's destructive tendencies as timeless as its special effects are dated. And 1968's Planet of the Apes (Fri April 17 & Sat April 18) harkens back to that halcyon era when relentlessly bleak movies about monkey overlords starred people in latex rubber and yak hair instead of Andy Serkis in a unitard.

As legally required by any sci-fi film festival, Ridley Scott's two great contributions to the genre, 1979's Alien (Thurs April 16 & Sun April 19) and the "final cut" of 1982's Blade Runner (Wed April 15 & Sat April 18) will screen. So will the director's cut of Alex Proyas' underseen 1998 mind-bender Dark City (Wed April 15), and the Wachowskis' The Matrix (Mon April 13 & Sat April 18). At a time when the Wachowskis are more famous for making ambitiously weird sci-fi movies that people don't see—Speed Racer, Cloud Atlas, Jupiter Ascending—revisiting their ambitiously weird sci-fi movie that everyone saw in 1999 seems appropriate. Speaking of beloved bombs: On Tuesday, April 14, Joss Whedon's excellent space-western Serenity (2005) will be introduced by PSU Urban Studies and Planning professor Carl Abbott, author of Big Sky Country: Reliving the American West in Serenity, Firefly, and American Science Fiction (it also screens Sun April 19).

Though Serenity gains much of its charm from diametrically opposing the gleaming idealism of Star Trek, it's worth noting Trekkies won't be left out: Star Trek II: The Wrath of Khan (1982) will screen twice (Fri April 17 & Sun April 19), both times preceded by the 1999 comedy Galaxy Quest, an unofficial Star Trek movie that might also be the best Star Trek movie. And while OMSI is likely relying on little more than hazy nostalgia to sell tickets to 1984's unremarkable The Last Starfighter, at least they're going all in: From noon-2 pm before The Last Starfighter's Saturday, April 18, screening, the Portland Retro Gaming Expo will set up old-school videogames, and they'll be joined by Portland and Seattle's Star Wars cosplaying and charity organization the Cloud City Garrison, so you can finally get that picture of yourself with Chewbacca you've been wanting for your mantel. And from noon-2 pm on Sunday, April 19—leading up to the screening of Galaxy Quest—attendees can get their pictures taken with "a Klingon, some Starfleet security officers, and other friends."

I hope that one of those "other friends" isn't Neelix. He's the only thing that could ruin a festival with this good of a lineup.