Time travel is a genre unto itself, one that spans sci-fi, mystery, fantasy, history and more. But there are distinct categories of time travel narratives, each with its own set of rules—and each with a different baked-in outlook.
Getting to a taxonomy of time travel stories, the first question is—who or what is actually time-traveling? Because while the first stories we think of involve spaceships and Deloreans, the oldest time travel stories are stories about…
1. SEEING THE FUTURE
In these stories, it is actually INFORMATION that travels through time. And this might be the most scientifically plausible form of time travel, one that is already happening all the time on the quantum level.
Visions of the future have shown up in literature and mythology for millennia, it’s just that we used to call them prophecy. But the fundamental storytelling device has changed little, even as it evolved with the times, manifesting in various communication technologies. Characters connect to the future through newspapers (the film It Happened Tomorrow, which inspired the show Early Edition), letters (The Lake House), radio (Frequency), photography (Time Lapse) and now, the Internet (my own recent novel The Future Is Yours, the reason I’m interested in sorting all this out.)
All these stories of peering forward in time differentiate into two categories on the basis of one crucial question: If you see the future, can you change it?
1A: Stories of Inevitable Foresight
These are stories where the future can be seen—but ultimately, what you see can’t be stopped.
The archetype for this form is one of the oldest works of dramatic literature in the Western canon—Sophocles’ play Oedipus Rex, where the titular king is warned by the seer Tiresias that he will murder his father and wed his mother… and despite his best efforts to the contrary, he ends up inadvertently doing just that (and then gouges his eyes out for good measure).
Stories of inevitable prediction speak to one of our deepest fears: that we have no free will, no agency, no power to control our fate. A glimpse of the future, foreknowledge of what’s to come, only ends up causing the events we aim to prevent.
Sound depressing? Maybe that’s why it’s a theme that spoke to sci-fi author Philip K. Dick, author of Minority Report— which is, for all its superficial differences, a story very similar to Oedipus Rex. It features a trio of precogs who dream of future-murders, and a cop assigned to prevent such killings—until he finds himself accused of one himself.
Dick was a pessimist about the prospect of free will, and in his story (spoiler alert!) his character ends up going through with the predicted murder. But perhaps unsurprisingly, when Steven Spielberg got hold of the same material, the outcome changed, and Tom Cruise’s version of the character was able to alter his destiny. How? Sheer force of movie-star charisma mostly. Which brings us to—
1B: Stories of Preventable Foresight
Other stories of seeing the future treat altering the timeline as quite evitable. In fact, the very act of viewing what’s ahead empowers the individual to change things, and prevent the foreseen events from coming to pass. That’s how Early Edition worked, with Kyla Chandler given the thankless daily task of averting tragedies only he could foresee.
But the prototype for this story form can be traced at least to 1843, in A Christmas Carol. Yes, even Dickens wrote some timey-wimey shenanigans; what else are the Ghosts of Christmas Past and Yet To Come? And when Scrooge beholds the pitiful sight of Tiny Tim dead, and his own neglected grave, he is promised a chance to rewrite the narrative if he can merely change his ways.
Which means that Dickens was much more of an optimist than Sophocles or Philip K. Dick. Being able to see the future and change it, whether through an epiphany or a magical newspaper, is the sort of world most of us want to believe in… whether that’s the way things actually work or not.
But in other types of stories, it’s not only information that travels through time. Many stories concern people getting to do so too—and the way authors treat those journeys says just as much about who they are and how they view the world.
2. TRAVELING TO THE FUTURE
One of the clearest progenitors of the time travel narrative, H.G. Wells’ The Time Machine, is about a man zipping off into the distant future. But the world he encounters—one full of peaceful Eloi and belligerent Morlocks—is so disconnected from our own, it’s hard to know why it’s not simply a story about aliens on another planet.
This points to a problem with time-travel forward. The future feels so unknowable, it often ends up being less interesting than we’d expect. That’s why some “travel into the future” stories make our present the future of the characters—like Time After Time, which features Jack the Ripper fleeing 1890’s London and winding up (via a time-machine that belongs to H.G. Wells) in 1970’s San Francisco (it’s as ridiculous as it sounds, and well worth a watch). But this plot device is really no different from the fish-out-of-water Rip Van Winkle premise, dressed up with technology.
Perhaps this is why “travel into the future” has perhaps been used most effectively as a last-minute twist ending, as in the original Planet of the Apes.
In other words—time-travel into the future is just not that special… maybe because we’re doing it all the time, at a consistent rate of 60 minutes per hour. And given that our own lifetimes have witnessed such seismic changes in technology and society, do we really need to imagine a cosmic leap forward to see things that will blow our minds?
That’s why the most interesting physical-time-travel stories have focused on…
3. TRAVELING TO THE PAST
Some of these stories are just touristy jaunts that don’t bother with the ramifications of intervening in history (like A Connecticut Yankee in King Arthur’s Court). Which is fine and well, but more interesting are stories that grapple with the question: Can we alter the past? And by implication… can we alter our own present? Which breaks the category down into two distinct groups…
3A: Changing History
Perhaps the most intuitive mode of time travel is where characters travel to the past, and in doing so, alter the present they left behind. Back to the Future is probably the most popular of all. It’s fun to meet your teenage parents, but if you mess things up, you risk erasing yourself from existence. So then you have to… fight off your mom’s sexual advances and help your dad save her from getting raped? (Yeah, I didn’t really get how messed-up that was as a kid either…) Fix the past, fix the present, life goes on.
Of course, beyond just keeping your parents married and yourself in the family portrait, what people dream of is using time travel to fix history, the easiest go-to being the plot to kill baby Hitler. But in the massive time travel canon, it’s almost exclusively villains who try to rewrite the past. Very few stories feature heroes changing history for the better. Butterfly effects are almost always negative, and even the most well-intentioned time travel plans (like saving Kennedy from assassination in Stephen King’s 11/22/63) result in horrible misfortune for the world (catastrophic earthquakes in that case, for, ya know, reasons).
All of which points to the fact that on some profound level, as much as our minds love playing with the possibilities of altering the timeline, we are deeply attached to the one we have, and innately suspicious of any effort to correct it. Which is why we have…
3B: Immutable Timelines
Stories where characters find themselves fundamentally incapable of altering history, regardless of their level of intervention. 12 Monkeys (and the French film it’s based on, La Jetee) tells the story of a time traveler seeking to prevent an apocalyptic manmade plague. He ultimately fails and realizes, too late, that as a child he witnessed the death of himself, as an older time traveler. The ending is incredibly satisfying—despite the fact that it’s profoundly fatalistic, suggestive of a world in which not even high-tech time-bending can save the human race from killing itself.
A less fatalistic example of this approach to time-rules is found in Avengers:Endgame, in which the characters travel to various moments throughout Marvel history to steal Infinity Stones (think Oceans 11 with a lot of fan-service). Smart Hulk (yes, seriously) gives the stipulation that history will “heal” itself of their interventions, preserving the timeline. On its face, this sounds like a lame gimme of a screenwriting rule — but turns out, it’s actually reasonably well-supported by recent experiments on quantum time travel. Science and sci-fi both point to the same idea: we can’t change the past.
4. TIME LOOPS
Which brings us to the final category—the pinnacle of unalterability—stories where a character is stuck reliving the same day again and again. The prototype here is the 1993 comedy Groundhog Day. The formula it set out brilliantly has been replicated in other genres, including but not limited to YA melodrama (Before I Fall), slasher-horror (Happy Death Day), sci-fi action with aliens (Edge of Tomorrow), sci-fi action without aliens (Source Code, ARQ), episodic existential-dramedy (Russian Doll) and then circling all the way back to comedy again in last year’s Palm Springs.
These films don’t merely share a high-concept, they all have essentially the same theme: life doesn’t change until you change. Which would seem to make them remarkably unoriginal, if not for the surprising fact that they’re ALL good. (Seriously, I’ll go to bat for Before I Fall). No doubt there are some bad time-loop movies that I missed, but the fact that one hyper-specific premise has resulted in so many excellent movies points to the fact that there is a deep, resonant truth to the notion of being trapped in time.
Of course, this is only a partial taxonomy of time travel, but even this incomplete catalogue points to a few key takeaways. Most time travel stories are cautionary tales. Attempting to meddle with history is punished; defying prophecy is futile; the best we can do is pull a Marty McFly and close the Pandora’s box we opened in the first place. These stories, for all their far-flung leaps through space and time, are ultimately about how, if we want to change our lived reality, we need to start with ourselves.