Great Scott! If my calculations are correct, it's
Back to the Future Day! And you know what that means: when we get this baby up to eighty-eight miles per hour, you're going to see some serious … discussion about the different types of time travel?!
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| That line isn't in the script … (source) |
More to the point, depictions of time travel in fiction can be classified into four types. These classifications are based on the purpose and volition of the traveler and/or their associates. More broadly, instances of time travel could be classified into "intentional" vs. "unintentional," but what's the fun in that? (Also, you run the risk of painting with too broad a brush—there is some utility in digging one layer deeper.) The four categories are as follows:
- Influence
- Surveillance
- Concomitance
- Coincidence
It's important to note that these four types aren't necessarily mutually exclusive within the same work, or even the same time-traveler's motives—for example, in
Superhero Black Hole, the main character at one point travels to the ancient Roman era in an attempt to save his skin (Concomitance) so he can survive long enough to stop the antagonist in the future (Influence).
Let's take a look at each one, with examples from media you may (or may not) be familiar with. For the purposes of this article, "time travel" encompasses only those instances where someone or something is actually displaced from its origin in time. Simply flinging a message into the future or past doesn't count unless it's on a physical medium.
Also,
beware of unmarked spoilers.
Influence
Back to the Future
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| Judging by the green graph behind him, that DeLorean either has one tricked-out subwoofer or one seriously leaky plutonium reservoir (source). |
It qualifies, but not how you might think: the Influence factor isn't in Marty ending up in 1955—that's Concomitance—but in him getting back to 1985. Marty wants to return the flow of events to how it was, in the sense that he belongs in the '80s. (For why he ended up thirty years in the past, see below.)
Star Trek
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| Your greenhouse gas emissions are without honor! (source) |
Oh, boy. So, so much time travel happens in Star Trek. The crew of the original series went back to the '70s in Star Trek IV: the Voyage Home to teach us, in a roundabout way, proper wildlife conservation practices. The Next Generation had "Firstborn" (S7E21), where future!Alexander basically tries to turn past!Alexander into John McClane. Deep Space Nine had "Trials and Tribble-ations" (S5E6), in which a Klingon with a bat'leth to grind hijacks the Orb of Time and tries to blow up Captain Kirk. Voyager had "Relativity" (S5E23), in which Temporal Investigations tries to stop someone from blowing up Voyager (interestingly, the culprit had also traveled through time in order to plant the thing, and basically manages to stop himself).
The Terminator
We see both the "affect" and "effect" senses in James Cameron's franchise-igniting sci-fi flick. John CENA!!!! Connor is the leader of the Resistance, fighting against Skynet and its robotic army. Skynet has managed to figure out how to make a time machine work and has hit upon the simple idea of killing Connor's mother and preventing his birth in the first place. (Who cares about the Butterfly Effect, anyway? Not Skynet, apparently.) That's how Ahnold finds himself in '80s-era Los Angeles. Kyle Reese, meanwhile, is sent back to stop the T-800 and keep the timeline intact—in more ways than one.
Continuum
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| Liber8 aw8s their f8 (source). |
The plot of this Canadian sci-fi series is set in motion when a terrorist cell, "Liber8," escapes a legal sentence to go back in time sixty-five years or so. Their plans involve blowing up a building and radicalizing a newborn. Not only do they succeed, but interestingly enough, they also end up killing off one major character's ancestor. Despite the fact that he's from the future, he still apparently survives.
Surveillance
"Surveillance" refers to an agent instigating time travel for purposes of observation. The agent can intend either to document events at the desired point in time as they happen, or they can simply test whether their methods for time travel actually work in the first place. Like Influence, the agent intends to make the trip; unlike it, they don't want to disturb. It's like window-shopping through the ages.
Back to the Future
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| One less minute to wait for the season premiere of Game of Thrones (source). |
Doc Brown had to test the DeLorean somehow, after all. Einstein, being a dog, can't himself choose to run the DeLorean, but he's under the auspices of the good Doctor, and that counts for our purposes.
The Time Machine (2002)
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| No Whammies, no Whammies… (source) |
In a nice example of the mutual compatibility of time travel types, Dr. Hartdegen's initial reasons for traveling into the future are to conduct research—he wants to see if humanity ever learned if changing the past is even possible, but can't wait like everybody else. He wasn't intending to actually alter the course of the future because of his travels there. All he wanted to do was learn if he could save his fiancée's life. (That would be Influence, but would have involved travel to the past to actively prevent her death.)
A Sound of Thunder
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| The description text for this image in Google Images read "An error occurred." This is an accurate summation of just about everything about this movie (source). |
I almost don't want to dignify this film with discussion, but it was one of the first examples that came to mind. The upshot is that there's a company that basically offers prehistoric safaris. You're not supposed to do anything except watch—there's even a pathway that gets generated so that you don't step on anything. Naturally, some idiot messes this up it doesn't go according to plan.
Primer
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| Randall Munroe comes about as close as anybody ever has to accurately summarizing the plot (source). |
Oh, boy. Shane Carruth's Primer is a real rat king of a movie, and some hold it to be the best time-travel movie of all time. The film ends up as a multi-car pileup of gambits and agendas, but the core reason for Abe and Aaron traveling through time in the first place is Surveillance—they want to see if the box actually works. The two Abes at the self-storage place pretty much confirmed that for Aaron … the first time around.
Concomitance
As
Baron Mordu said, "The bill comes due." A concomitant event occurs as a consequence of some other action. Here, the actual act of traveling through time is not usually considered a "consequence" for our purposes (otherwise every instance would qualify); instead, "concomitance" refers to the motivation behind the time travel. Someone who researches and participates in time travel because he wants to does not travel because of concomitance, but a criminal forced by his captors to serve as a guinea pig for a new time-travel method does. It's kind of surprising how rare this motive is.
Back to the Future
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| Am I the only one who doesn't think the future as presented in Back to the Future Part II was all that great aside from hoverboards and self-velcroing Nikes? (source) |
A bit of an odd example because it takes place due to actions Marty McFly hasn't performed yet, but the reason that Doc Brown takes Marty to 2015 at the end of the film (and in the first part of Back to the Future, Part II) is ultimately because Marty stupidly gets involved in a street race, breaks his hand, can't play the guitar anymore, and turns into a worn-out, underachieving shell of a man who isn't there to help his kid stay out of trouble. Perhaps stretching it a bit, but hey, I've got to tie this into the franchise somehow.
Star Trek
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| Overall, the double-Picard shots in this episode were extremely well-done (source). |
Probably the clearest example of Concomitance for the
Trek franchise is
The Next Generation S2E13, "Time Squared." The
Enterprise runs across a shuttlecraft tumbling in space. It turns out to be one of theirs, and Captain Picard is in it. Except, Captain Picard is on the bridge, and the
El-Baz is sitting right next to itself in the shuttle bay. It turns out that this is future!Picard, who tried to escape the
Negative Space Wedgie of the week, only for it to destroy the future!
Enterprise and fling him back six hours so he could try again. Present!Picard shoots him with a phaser, the dead body and shuttlecraft vanish, the Negative Space Wedgie is satisfied, and Picard is left to grapple with whether he just committed suicide or murder. (Incidentally, per
Deep Space Nine, you could probably charge him with the latter.)
Samurai Jack
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| Aku's not staring so much in fear of Jack's attack as he is in awe of his hair (source). |
From Jack's perspective, at least, the raison d'être for the series is due to Concomitance. His initial temporal displacement is a direct consequence of his challenging Aku. Jack himself didn't want to end up in the future. Note that, on the flipside, Aku's motivation was Influence—getting rid of Jack let him move forward with his plans.
Looper
The gist of Looper is that really bad dudes from the future send people back in time for really bad dudes in the present to kill. (Hard to prove a murder if there's no body, right?) Why these victims are sent back in time isn't always known, but part of the contract with these hitmen involves having themselves sent back. Basically, past!guy kills future!guy in the past—a result of his prior actions.
Coincidence
Stuff happens in general. Sometimes, stuff happens to people. With respect to time travel, "coincidence" considers both accidents and happenstance, and is basically an umbrella term for any time travel where the traveler did not initiate the travel of his own volition and where said travel did not result directly from his actions. "Coincidence" may not be the best name, but it rhymes and doesn't imply that the traveler had anything to do with it.
Back to the Future
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| I'd be remiss if I didn't find a way to work this in (source). |
Marty didn't ask for the Libyans. It's not his fault that he got shot at. When he was getting shot at, his only thought was getting out of dodge. Unfortunately, in order to get out of dodge, he had to get into a heavily-modded DMC, and he ended up stranded in the '50s.
The Twilight Zone
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| Peter valiantly tries to change history (source). |
In "Back There" (S2E13), Peter Corrigan ends up in 1865 following a discussion about whether one can influence events via time travel. He doesn't intend to get transported to the past, and while he does try to change it—and sort of does, if only in a way that ends up with one guy getting rich—he didn't set out to do any of that initially.
Heroes
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| Up high! Down low! Too slow—what the heck?! (source) |
"Dual" (S3E13—what is it with all the episode thirteens in this post?) provides an instance of Coincidence for Hiro Nakamura, of all people. Hiro has been stranded in the past following his forcible depowering (how he got there is irrelevant for now). His brother Ando and their teammate Daphne manage to save the day for him thanks to some quick thinking. Hiro is returned and the status quo more-or-less restored when Ando augments Daphne's super-speed abilities so that she can travel faster than light.
Continuum
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| In the future, legibility will be sacrificed in favor of looking stereotypically futuristic (source). |
Liber8's voyage into the past was discussed above, but Kiera Cameron ends up in 2012 by accident. Liber8 was supposed to Influence history; Cameron joining them wasn't intended by anyone involved. She just happened to be in the right place at the wrong time.
Were my calculations correct? Is this too heavy? Let me know in the DeLoreans!
