People sometimes mistake short stories for trifles, wee vignettes that are over before they start. But there's a reason why many of the best movies are based on short fiction rather than novels: a short story is just the right length to blow your mind. Here are 18 science fiction and short stories that rock our world.

Top image: Cover art for The Martian Way and Other Stories by Isaac Asimov, Art by Paul Lehr

1) "The Last Question" by Isaac Asimov

This is one of the all-time great idea-driven stories, and it's one that manages to be both cosmic and poignant. In 2061, humans create the first truly awesome supercomputer, Multivac, and decide to ask it how the net amount of entropy in the universe could be reduced. This turns out to be kind of a tricky question, and it takes rather a long time to get a satisfactory answer. This story contains all of Asimov's penchant for big-picture storytelling, in one brilliant dose. Amazon/Powells

2) "The Daemon Lover" by Shirley Jackson

Everybody thinks of "The Lottery" as Jackson's all-time great short story, but as Joyce Carol Oates says in her introduction to Jackson's collected stories, this one is actually "deeper, more mysterious, and more disturbing." A woman is engaged to be married, but she can't remember what her fiance looks like. And when she goes looking for him, she can't find him — it's a great gothic horror story, but also a beautifully written look at aging and vulnerability. You can listen to Jackson reading it here. Amazon/Powells

3) "The Janitor on Mars" by Martin Amis

Basically, there's a robot living on Mars, but it's been programmed not to reveal itself to Earth people until we've changed the atmosphere of our planet enough that we are already doomed to extinction. This happens in 2049, and the encounter with an ancient, extraterrestrial machine, which calls itself the "janitor," causes a worldwide sensation. The janitor on Mars reveals the three billion year history of Martian civilization, and why it ended suddenly. Meanwhile, back on Earth, a boy named Timmy has been raped so violently he's in the school infirmary — and the school janitor suspects the principal did it. The juxtaposition between the huge-picture "end of civilizations" stuff and the personal, small-scale stuff is just brilliant. Amazon/Powells

4) "Uncle Chaim and Aunt Rifke and the Angel" by Peter S. Beagle

Really, you should just read all of Beagle's short stories — they're available in nice editions from Tachyon Books, plus you can still get Mirror Kingdoms: The Best of Peter S. Beagle used. Beagle's stories are sly, endearing, and moving when you least expect it. This one features the narrator reminiscing about his childhood, and the angel that visited his uncle and demanded to be painted. Even though Beagle's tales of adults are brilliant, his short fiction about childhood is some of his most provocative, and this story is a miracle. (Amazon)

5) "Aye, And Gomorrah" by Samuel R. Delany

Let's just get this out of the way right off the bat: The whole story collection Dangerous Visions remains required reading even after nearly 50 years. Not every story in Dangerous Visions has aged well, but they're pretty much all fascinating and audacious. The most provocative of these stories, even after all this time, remains Delany's Nebula-winning tale of Spacers, who have been neutered in order to survive in deep space, and the Frelks who fetishize them sexually. Delany's world feels lived-in and vast, even as he tells a story of sex work, subcultures and terrible, terrible loneliness. (Amazon/Powells)

6) "There Will Come Soft Rains" by Ray Bradbury

Wasn't sure which Bradbury short story to include here — because they're pretty much all gems. But this one, in which basically a smart house keeps going after its human inhabitants are all dead, is in a special league in the knife-twisting sweepstakes. Like a lot of stories in the years following World War II, it's concerned with the threat of nuclear annihilation, but also with how our technology might outlive us. The whole thing is one big gut-punch. (Amazon/Powells)

7) "Evil Robot Monkey" by Mary Robinette Kowal

This is a pretty simple story, but it contains enough ideas and emotional heft to stick with you for a long time after reading. Sly is a monkey who's been uplifted thanks to a cybernetic implant that gives him human-level intelligence — but that doesn't mean he's not still a monkey. By the end of the story, you absolutely feel for Sly, who is one of those tragic characters who can't escape his circumstances, but he's smart enough to understand his situation. You can read the story, and hear it read by Kowal, here.

8) "That Only A Mother " by Judith Merril

Basically, this is a story about a mother and her mutant baby — at a few months old, her baby can talk in complete paragraphs and sing beautifully. And at first, you think it's kind of sweet that this baby is so precocious, considering all the other kinds of mutations she could have had. The note of danger and tension in the story comes from the mother's correspondence with her husband Hank, who's away at the front in World War III. Her letters to Hank are flowery and jubilant, but Hank's terse telegraphs make you wonder about just what will happen when Hank comes home and meets his special little girl. (Amazon)

9) "Escape From Spiderhead" by George Saunders

This one story has a lot of Saunders' most frequent concerns, but with even more creepiness and dystopian satire than usual. The main character is a test subject in a special facility, where they completely control his mind and emotions using bizarre drugs — and this leads to a lot of weirdly unsettling sex scenes. But that's just the beginning. Fiction is full of dystopias where corporations or science gone mad are controlling people, but this story still stands out for how powerfully it examines questions of what makes us who we are. But mostly, just creepy as hell. Like a lot of the stories on this list, I chose this one because it keeps bugging me. (Amazon/Powells)

10) "Solitude" by Ursula K. Le Guin

Le Guin's best fiction often looks at the meetings between cultures, and the efforts of an outsider to understand a strange culture, and this story is no exception. The main character is in a unique position to discover how the people on another planet interact, because she's a little girl and will be accepted by them in a way that her mother won't. But this leads, over time, to a rift between the girl and her mother, who wind up having been raised in different cultures. There are so many brilliant ideas and powerful emotions in this one short story — it's reminiscent of Le Guin's Left Hand of Darkness, but more personal. (Amazon/Powells)

11) "The Girl Who Was Plugged In" by James Tiptree, Jr.

Along with E.M. Forster's "The Machine Stops" and some of Philip K. Dick's weirder stories about advertising and surveillance, this novella feels weirdly prescient — it really feels like it could be an episode of Black Mirror, in fact. In the near future, instead of advertising, corporations own celebrities, who are basically "famous for being famous" and go around conspicuously buying and using the companies' products. One of these is Delphi, a teen girl who's beautiful but brain-dead (literally), and she's controlled cybernetically by a normal girl, whose body has been damaged by a disease. (Amazon/Powells)

12) "Message in a Bottle" by Nalo Hopkinson

This is a somewhat hard-to-categorize story — without giving too much away, it's another story about a weird child who's not entirely what she appears to be. And Kamla isn't actually a child at all: She's a visitor from the future, who's come back in time to collect something. The main character's interactions with this eerie visitor are fascinating and kind of intense, and the story's big "twist" is one of those things that makes you rethink humanity's place in the world. (Amazon/Powells)

13) "The Seventh Voyage" by Stanislaw Lem

Speaking of time travel... this chaotic, insane story is Lem at his absolute best and silliest. Ijon Tichy is traveling through a strange region of space, when his ship's rudder gets damaged. But that's not his main problem — he goes through some kind of time warp, and soon the ship is full of different versions of Ijon Tichy from the past and the future. Can he live with himself? Especially when there are so many of him? (Amazon/Powells)

14) "The Lifecycle of Software Objects" by Ted Chiang

Chiang famously has never written a novel — just these perfect, mind-altering pieces of short fiction. And yet, Chiang packs enough cleverness, and enough twists and turns, into his stories for a whole series of books. This novella, about digital creatures that are "raised" by a community of developers and enthusiasts, is no exception. Chiang explores deep questions about the nature of consciousness and innocence, but then serves up surprise after surprise, turning your expectations on their head over and over again. (Amazon/Powells)

15) "Stone Animals" by Kelly Link

All of Link's short stories are provocative and vexing, but this is probably my favorite — the story of a family that goes to live at a house in the middle of nowhere, while the husband keeps commuting back into the city. There are no answers here, and not even any satisfying questions, but you'll keep looking deeper into this story to find your own meaning in its gothic strangeness. Electric Literature's mini-essay about "Stone Animals" is well worth reading for more insights. (Amazon/Powells)

16) "The Cartographer Wasps and the Anarchist Bees" by E. Lily Yu

This is one of those great stories that works both as a metaphor (for colonialism, for what happens when one nation makes another a "client state") but also as a straight-up piece of speculative biology — a group of wasps conquer a group of bees, and some of the highly educated wasps think that they can take some of the bee offspring and turn them into scholars. But the bee colony also has to work way harder to service the wasps' needs as well as its own. And this arrangement has vastly unpredictable results, for both sides. There are huge lessons for human societies here, but also something irreduceably alien. (Amazon)

17) "The Father Thing" by Philip K. Dick

Unlike Ted Chiang and Kelly Link, Dick isn't primarily known for his short stories — but his short fiction is often his most powerful and well-constructed writing. There's a reason why most of the movies of Dick's works have been based on short fiction rather than his novels. Subterranean Press did a five-volume set of Dick's complete short stories, and it's an eye-opening assortment of brilliant ideas, with enough inventiveness to sustain a novel but none of the meandering and wheel-spinning. This one, though, stands on its own — at first, it feels like a weird Twilight Zone episode, as a kid sees his father standing in the garage with a duplicate father. But it soon turns into a kind of Body Snatchers motif, with only a small group of kids aware of what's going on — and those kids behave in a way that Spielberg would never sanction. (Amazon/Powells)

18) "The Paper Menagerie" by Ken Liu

This story swept the Hugo, Nebula and World Fantasy Awards, and we were proud to republish it at io9. It's a tear-jerking story about origami that comes to life — but it's really about the challenges faced by children who are caught between two cultures, and how internalized racism can damage a family. (Amazon)

We're just scratching the surface here — I wanted to include stories by Carol Emshwiller, Theodore Sturgeon, Maureen McHugh, Karen Joy Fowler, Robert A. Heinlein and a ton of others, but couldn't settle on just one. What's your favorite short story?