Seven (or Three) Types of Time-Travel Elasticity

In a previous post, I claimed to have spent Worldcon discussing such subjects as the “seven types of elasticity in time travel” and “four types of alternate technological history.” Ted Chiang was kind enough to take time off from his furious writing schedule and inquire if I could elaborate. (Bluff-calling bastard.)

Certainly, I can elaborate. I wouldn’t just throw those numbers around like they were nothing, would I?

Tonight, I’ll start with the major forms of time-travel elasticity. Seven of them. Um, yes.

But let us start by defining our terms. For those of you who may not know, elasticity in time travel stories is a tendency for historical events to wind up the way they’re “supposed to,” a narrative device to make things palatable to those of us living in a fixed history. Elasticity is the timeline “snapping back” to its “proper” shape, more or less. Generally, TV and Hollywood time travel tales are more conservative, employing firmer elastics than literary sf, which doesn’t mind messing up the timeline a little, or destroying it altogether.

So here are the seven flavors of time travel in all their glory. Well, okay, the first three:

Type 1: The Full Elastic Jacket
Doug and Tony go back in time, and find themselves on the Titanic. So they head up to the bridge and tell the captain that the ship will soon hit an iceberg and sink. Full of Victorian hubris (okay, Edwardian hubris, and maybe some gout) the Captain proclaims, “This ship is unsinkable!”

Doug and Tony try various other avenues, but nothing they do will change history. The Titanic sinks on schedule, but not before they are whisked back into the present, having learned a valuable lesson about pride going before a sink. And that you can’t to jack with a time tunnel.

This is an actual Time Tunnel episode. It’s also the plot of a kid’s book I read once. But you know what? There are 1,005 books on Amazon with the word “Titanic” in the title, so I ain’t looking it up.

Doug and Tony weigh the ethics of saving some male Guggenheims and a few hundred lower-class types.

Type 2: Achy Breaky Time
In this schema, travelers can go back in time and change history, but they better not mess it up too much! Basically, the timeline is like your parents’ liquor cabinet. You don’t have to leave it exactly like you found it, but be careful. One drop too many and there’s going to be a freakout of major proportions.

John Varley’s Millenium is about Achy Breaky Time. Travelers from the future jump back to the present to steal people who are seconds away from dying in plane crashes. They use these lucky/unlucky souls to repopulate their own barren era.

Generally, the plane crash destroys all evidence of the travelers’ appearance in our time, preserving the timeline from paradox. But one day, a weapon from the future is accidentally left behind, survives the crash, and is discovered by a present-day crash investigator. This anachronistic artifact begins a chain of changes in the timetime, history slowly stretching out of shape. The changes build up slowly but surely, until “timequakes” start to rumble. Unless the anomaly is fixed, the timeline itself may be destroyed, which pretty much means everyone, everywhere and everywhen, is doomed. Time is elastic like a rubber band; you can change its form, but it will eventually snap.

High stakes. Except, of course, that if the heroes fail all the people they were trying to save never existed in the first place. No harm, no foul.

Also, when exactly are the timequakes happening? And when the heroes say that time is running out, which time is running out?

Type 3: Heisenberged Time
In Kage Baker’s “Company” novels, you can change history, but not recorded history. Thus the agents of the Company can go back and grab extinct species, lost artworks, and other vanished ephemera. But these agents are limited in their actions by time’s elastic, which is inscribed in the history books in their future employers’ libraries.

Exactly how this works scientifically, and what constitutes “recorded history,” is best not thought about too much. But it does eliminate paradoxes, because we all know that all the important history is written down.

Baker’s other ingenious move is to make time travel possible back to any point, as long as it’s before time travel was invented. All eras after that moment are inaccessible, which is a totally cool and Heisenburgian idea: The invention of time travel has changed the nature of time itself, changing it from elastic to totally locked up and inaccessible.

Okay, that’s three. I’m going to sleep now, and I’ll do the other four . . . soon. (Help me out here, guys.)

And then the four types of alternate technology. Oh, yeah, looking forward to those.

17 thoughts on “Seven (or Three) Types of Time-Travel Elasticity

  1. I don’t know if it’s Type 1a or Type 4, but there’s the kind where it turns out that whatever intervention you were trying to make was already part of your past when you started.

    There’s the Connie Willis model (To Say Nothing of the Dog), where it’s flat-out impossible to get near certain pivotal events, and often if you do change something the universe will snap back in such a way that at some point down the line (possibly way down the line, maybe even farther into the future than your departure) things end up more or less the way they were. It gets pretty teleological.

    There’s the Terry Pratchett model (Mort), where the “real” timeline keeps trying to reassert itself, possibly in an amusing and hallucinatory way, in which people refuse to believe that events didn’t happen the way they were supposed to.

    …Okay, somebody else’s turn.

  2. Can’t reference this one, but it seems to fit the “elasticity” tag very nicely. If you change something, the change propagates (yes, through meta-time or whatever) up to the point where you launched your time machine. The circumstances of your departure probably change somewhat, and that change propagates back down, causing further changes that come back up, etc etc. But each time the resulting alterations are less severe, so eventually things settle back down to a stable single history.

    (Why should they be less severe each time? Erm… because the plot device doesn’t work otherwise?)

    Imagine twanging a rubber band, it vibrates back and forth for a while but eventually settles down. Except that it needn’t settle into the old shape, _or_ into the shape you intended to push it into. And mostly it settles into a shape without time travel, because that’s (unsurprisingly) more stable.

  3. David: Yeah, I know that one. At the end of the tale, the protags always open that one last pigeon-hole in the old desk and find the note they left for themselves, or whatever. But that pigeon-hole had been stuck until then; the note didn’t just “appear.”

    tikitu: That’s a cool one. I think it’s Larry Niven who said that any universe in which time travel is invented eventually collapses into a universe in which it’s not. (That’s “collapses” in the sense of moving to a state of lower energy. The only stable timeline is one without time machines, after all.)

    “Meta-time” seems like a useful coinage.

  4. You seem well on your way to conquering the 7 types of elasticity, so I’ll contribute one type of alternate technology I picked up while bluffing my way through a panel on the subject at the last WorldCon. 1)Alternate Standards; think betamax vs. vhs or direct current versus alternating current. A very smart woman who was an engineer, train expert and all around alternate technology geek claimed she could not find a single instance in history where a standard was chosen because it was better; standards, she claims are always chosen for non-technological, often arbitrary, reasons.

  5. There’s also the really simple form — the one where any changes in the past change the future completely. Total elasticity — in fact, elasticity would be the wrong word. Used by Orson Scott Card in Pastwatch: The Redemption of Christopher Columbus and by The Simpsons in the Toaster of Time segment from a Treehouse of Terror episode.

    (I just typed out a long digression about the actual status of time travel in Kage Baker’s Company universe, before realizing that it was full of spoilers and obnoxiously pedantic. Suffice it to say that (a) she’s brilliant, and (b) she appears to subvert many of the stated rules by the third book or thereabouts. The Heisenbergian description of elasticity is what The Company presents as truth in the books, but whether it’s entirely true is another question. Time-travel stories where the characters themselves don’t know the parameters probably don’t deserve their own category, but they’re some of the most interesting.)

  6. Branched Parallel Universes: You can change the past, but doing so simply creates a parallel universe. When you come back, you may or may not come back to your “own” present. This is more common as a parallel-worlds plot device than a time travel device, though.

    Explaining History: It turns out that the way things are only occurred because some intrepid time travellers went back and changed history from the way things were. For instance, the Doctor Who episode “Earthshock”, which explains what really killed the dinosaurs.

    The Heroes Can Fix It: Our Heroes somehow learn that Something’s Not Right (because they’re, you know, heroes), find that the past has been Tampered With, and go back to Fix It. An extremely common comic book superhero plot, first made famous by the original Degaton story in All-Star Comics in the 40s, in which he (a-heh) wiped out modern technology by changing the outcome of the Battle of Arbela (sp?).

  7. don’t know if this qualifies as alternate technology but this is what i’m using in my novel right now:
    in our past, aliens land and die and leave their incredibly advanced and conveniently easy-to-use technology behind (cf. “hand-waving”.) humans take it over and use it to do things they would never otherwise be able to do, in our past or in our present. unfortunately, the technology is so advanced that they can’t reverse engineer it. however, the fact that humans without, say, combustion engines or electricity, can fly to mars necessitates the creation of a secondary, human-made technology that caters to human needs arising from the use of this alien technology. e.g. a man-propelled (with a hand-crank) sledge to ride on the ice canals humans create on mars.

    also, before the advent of the term “mullet”, i used to refer to that hairstyle as “achy-breaky hair”, so it’s good that that adjective is back in circulation.

  8. Wow. fascinating. So, am I to take it (not being from the SF community) that the established acceptable time travel approach is one of time-elasticity, rather than actually time travel “changing” time a’la “Back to the Future” and such? Is that approach frowned upon, or is it written off as a “parallel worlds” story?

    In the romance genre, you’re lucky if the time travel plotline is used for anything more than a device to get the heroine into poufy long skirts and on a horse. Lots of being hit on the head with a magic rock in modern Cleveland and waking up in 15th century Scotland and the like. I don’t read TT romance for that reason. I have read Willis and even Stephen Baxter, though I don’t know if it’s possible to understand exactly what he’s getting at without a PhD in String Theory.

    I’d been trying to study the way time travel works in fiction (you should see my Netflix queue) and had THOUGHT I’d boiled it down to: 1) this was the way it was supposed to be (a’la THE TERMINATOR); 2) you can’t change anything, even if you try; 3) parallel worlds; 4) actually changing the future from the past.

    This is obviously much more complicated. Perhaps I need to start hanging with the SF folks more often.

  9. No, Diana, the changing thing happens fairly often, too. (Though Back to the Future’s way of dealing with the paradoxes by having the protagonist feel vaguely ill and start slowly fading away would probably be frowned upon by a lot of hard SF types.) I think what we’re talking about here is mostly variations on (1) and (2) — which could be treated as variants of “No, you can’t change anything,” with (3) and (4) as variants of “Yes, you can.”

  10. Thanks, David! I see what you mean. I think I’d have a greater understanding of those later ones if I’d actually read any of the Company novels. How would the “hard SF” types feel about the time travel in “Frequency” wherein the future would just suddenly change and even the “time traveler” (quotes because only his voice traveled) would have a difficult time remembering the original timeline?

    I think I can accept a variety of explanations as long as the logic works within the context of each story and they don’t go changing rules on me halfway through. For instance, I was fine with The Terminator, but disturbed how the theory was perverted in T2, and despite the fact that I hated almost everything about the third one, I was pleased that they made a few steps towards going back to the original interpretation of how time worked.

    Looking forward to the other three!

  11. I think the hard SF answer would have to be that you remember your original timeline, period. Either that or “you” never existed (any more, that is, after… um… having trouble with my tenses here…), though there may now be some other you around who remembers the new timeline.

    Though you might be able to get around that by waving your hands and saying “quantum” a lot.

  12. I believe it was Asimov, who in the END OF ETERNITY, submitted the “wave” theory of elastic time, that the effects of any change would be most noticable immediately after the point of interference/insertion, but would gradually diminish in intensity as you moved past the event. So, killing Hitler would radically alter the 20th century, marginally alter the 21st or 22nd century, and might leave the 23rd century or beyond virtually untouched and have no effect on the 30th century at all. Of course, larger alterations would carry further forwards, while smaller ones would fade out more rapidly.

    Oddly, this reminds me of a recent article I read on the resurgence of the “Great Man” theory of history. The idea that, at any given time, there are about 12 people who are creating the world had falled out of academic favor for some decades, replaced with the notion that economic, social, political etc forces were shaping events more than individuals, who were simply stepping in to fill roles dictated for them by larger forces. I.e., if you did assassinate Hitler, someone else would have stepped into the power vacuum in Germany and mobilized tensions there to similar effect. However, ironically, George W. has renewed interest in the “Great Man” theory. While the artile wasn’t suggesting W was in any way “great,” it pointed out that in almost-single handedly forcing a war that a) wasn’t necessary and b) wasn’t popular with congress, the people, or the world at large, he has demonstrated how much (catastrophic) effect one individual really can have.

    The other thing this discussion brings to mind is the way that science filters through into pop culture and effects our fictions. The original Star Trek very much adhered to the notion of “one timeline”, which, when broken, was always repaired – the break and it’s correction (as Spock points out in “City on the Edge of Forever”) always part of the design. This holds sway through the TNG episode, “Yesterday’s Enterprise,” in which Guinan senses the wrongness of a universe in with the Federation and Klingon Empire are at war, and impresses Picard on the necessity of repairing the damage. (Picard raises the question, “How do we know this timeline isn’t any more right than any other?” and Guinan stares him down.)

    But this notion of a single timeline begins to break down with the latter episode “Parallels”, which sees Worf permeating through a variety of alternative timelines until everything culminates in a clusterfuck of thousands of Enterprises from a myriad different universes.

    By Deep Space Nine, the notion of one time-line has radically broken down, as withness an episode whose title escapes me, in which Chief O’Brien is constantly teleporting back and forth to a future in which the station is destroyed. Despite the fact that each trip exposes him to radiation poisoning, he makes one final attempt to avert the encroaching disaster, meets himself of just minutes later on, dies, and sends his minutes-into-the-future self back in his stead. Upon his return, he wonders if he really has the right to call Kieko his wife, given that “her” O’Brien died in a timeline that was then prevented from occuring, and is reassured by his best friend that he’s still the Chief, even if his memories are out of whack by a few minutes. Since “most of him” is the same, that’s good enough.

    Finally, when we get to Voyager’s first few seasons (where my knowledge of Trek ends, as my viewing of Trek did too), time has become elastic, fractal, alterable, permeable, and generally good for twisting into any shape the writers need. The two-part episode “Future’s End” sees multiple versions of characters encountered with no attempt to match cause to effect. Here, a crashlanding in the past has resulted in a boom in 1990s computer technology (seemingly the boom we ourselves experienced – thus the alteration IS the correct time), but the 29th Century timecop that is sent to prevent it is re-encountered twice, once as a sane individual aware of the outcome of the episode’s action, and once as a homeless man wandering deranged from the initial crash. Both versions co-exist in the same (final) timeline, and alterations and corrections made in the episode do not erase or negate the mad homeless version’s existance. I quite watching soon afterwards, but kept enough tabs on the show to know that they continued to play with multiple versions of their characters, and multiple co-existing and interacting timelines.

    I haven’t quite put my finger on it yet, but I think that the move from an absolute time to fluid/fractal timelines somehow coincides with blurring questions of individuality and identity unconsciously coopted from the zeitgeist. It used to give me fits when Jeri Taylor would tell me “absolutely the holographic doctor is a person” and Brannon Braga would turn around and tell me “absolutely he is not.” They didn’t know themselves, but unconsciously, a lot of that series was about ascribing “personhood” to inanimate, but sentient-seeming, objects, which, to me, was perfectly appropriate for and indicative of an age where a woman ran over a biker because her tamaguchi needed food. As tragic as that sounds, one day our robot masters will site it as a watershed in human/machine empathy.

  13. Speaking of time travel movies (and the issue of the time traveller remembering different timelines), we have “The Butterfly Affect”, a surprisingly non-sucky movie in which Ashton Kutcher (I know. I know) discovers that the blackouts he experienced as a child were actually his adult self inhabiting his body, and goes about making things better, worse, much worse, much much much worse, and so on. Every time he returns to his own present, however, he gets migraines from having to accomodate yet another lifetime of memories. There’s even a hilarious scene in which his doctor looks at MRIs as if they were a disk-space usage diagram: “It’s almost as if… you were storing the memories of two lifetimes!”

  14. Ben Rosenbaum and I discussed this a bit elsewhere, but I’ll just add that the idea that time is unchangeable — that any attempt you make to change the past actually creates the past you already knew — is, in philosophical terms, essentially the same as the classical notion of fate, i.e. your destiny is predetermined. The idea that time is completely changeable is essentially the same as the idea of free will, i.e. individual choices are meaningful.

    The various forms of elasticity constitute a middle ground, where you can have a little of both. I think they’re popular because nowadays we’re attracted to both notions: we like the idea that some things are meant to be, but we also like the idea that our choices matter. (In the past, people were more accepting of the idea of fate than they are now, I think.)

    From a physics standpoint, I think you can argue for either immutable time or radically changeable time (or a multiverse), but I don’t know of any basis for an elastic model. Immutable time is a consequence of various physical theories, including special relativity. But if you posit that you can change anything, the mathematics of chaotic systems implies that shifting even a single molecule will eventually result in global changes.

  15. You also talked about this subject in your essay for Seven Seasons of Buffy, did you not? Very fascinating. Plus: Buffy is awesome.

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