Why do we step inside the dreams of science-fiction heroes so often? We're already in the future, or on an alien world, so why take an extra leap into the world of the unreal? Here are some theories.

After compiling 43 clips of science-fiction dream sequences, we started to wonder exactly why we invade people's dreams so often in SF stories. What purpose does this unreality serve?

We all want to venture past our own limited little reality fields and pop our limiting bubbles of experience — and sometimes aliens, spaceships, time-machines and weird mutations just aren't enough to make that possible. Sometimes we have to get all the way liminal. Stand in the doorway for a bit.

But more specifically, here are some reasons why science fiction gets so dream-happy:


1) The cheap foreshadowing

So we haven't thought about the Borg in months, and they haven't flashed so much as a single implant around these parts. But they're never far from our thoughts — or our dreams, for that matter. And it's just a nifty coincidence — and by "nifty," we mean "ominous and horrifying" — that our hero has a terrible dream about the Borg right before they pop up again. Such a dream does double duty: it reminds us of exactly what the Borg are about and why they're so fearsome. And it sets the mood for another round of Borgian devilry.

2) The prophetic dream

This is similar to the use of dreams as foreshadowing, but usually the foreshadowing dream also includes some actual useful information that our heroes can decipher and use against the monster/villain later. The prophetic dream is a plot device as well as (or sometimes instead of) a grace note. It's not just thrown in for effect, it's actually providing useful info, or at least clues to future developments. The frequent dream sequences in Buffy The Vampire Slayer often set up developments years down the road, like the coming of Dawn. A cruder version is the Doctor's dream at the start of the Doctor Who story "The Time Monster," which gives him tons 'o' clues.


3) Escaping the straitjacket of realism

Science fiction often works really hard to establish a mood of complete realism, paradoxically because it features so many elements that don't, and maybe couldn't, exist in our world. And sometimes, the only excuse for letting go of that need for realism is to stick in a dream sequence, where everything goes loopy.


4) Heightened realism

On the other hand, if people really did meet aliens or their own grandparents, or whatever, people would probably have severe, bizarre mental reactions as a result. Reactions that, honestly, would seem over the top or crazy if you tried to depict them normally. So sometimes the only way to convey a realistic sense of humans coming face-to-face with the unreal is by representing their terror and confusion in the form of an alarming dream. It's actually a form of added realism.

5) Thematic gracenotes

This is something that seemed to leap out from many of the dream sequences we looked over. Like Fahrenheit 451, for example — the hero is facing a conflict, or a mind-blowing decision, and we see that mental anguish amplified in a dream sequence. Preferably full of whirling shapes, and faces going around in a circle. Whoosh.


6) The easy scare that doesn't break any toys

Oh no, Ripley has an alien in her stomach, and it just burst out! Oh, except she doesn't, and it didn't. False alarm, folks.


7) Padding the running length.

What do you mean, we still have another ten minutes left? Do we have any explosives we haven't set off? No? Can we afford another monster costume or some extra CG? No? Okay, how about a long, trippy dream sequence where people stand around and recite e.e. cummings. It's puddlewonderful — in space! The fans will be debating what it means for decades...

8) Up the surrealism ante.

Imagine you're David Lynch. Okay, that may be asking too much. But pretend for a moment that you're impersonating a guy (or Laura Dern) and who has weird hair. And the person you're impersonating has done a lot of drugs, and it's making him or her have loopy visions of worm babies. What can you possibly do to make this guy (or Laura) have more weirdness on top of that? How about a totally batfreak dreamsequence, preferably featuring David Bowie? Or maybe a tiny radiator lady with facial hair?


9) Meeting the alien

Sometimes alien creatures (and gods, and demons) are so alien that no real-life encounter will work. The only way we can talk to them, or have any kind of meaningful communication, is in a dream, or a dreamlike world, where everything is semi-nonsensical and there's a bit of vaseline on the lens... because we're meeting a consciousness that's totally unlike our own.


10) Extra sexiness without consequences

And most importantly, we want to see Mulder shirtless and handcuffed. We want to see Sookie and Eric doing the wild thing. We crave random titillation, and we don't care if it makes sense in the context of the story. In fact, the less sense it makes, or the more it hints at undercurrents of sexitude under the surface, the more exciting it is. So it's almost mandatory for dream sequences to include "I can't believe they went there" friskiness.

The truth is, we want to be smacked in the face with strangeness. Our desire for the bizarre and ridiculous is so much greater than our pitiful suspension of disbelief that you need to short-circuit the whole "is this really happening" question.