Often in discussions on time travel(theoretical of course…oh god I’ve said too much!) from discussing fictional films to more educated musings there seems to be a given that there is an original timeline where the time travel did not take place.
Just for example the movie Terminator, you’ll see people wonder how Skynet came about the first time around and who was John Conner’s father the first time around. It seemed pretty clear to me there was no “first time” and what we see is what has always been, nothing changed.
I realize this is all pie in the sky nonsense but I’m wondering if I am missing something obvious here.
Well, of course. But even if there is an “original” timeline . . . why do people assume that’s what we’re in? We could be the result of that stepped-on butterfly.
Closed timelike loops can form pseudo-stable eddies in the timestream, especially for trivial things in the Big Time, such as the parentage of one individual or the nature of a civilization on one planet.
Of course, in a work of fiction, like a movie or a novel, there are two sorts of time: the timeline within the fictional world, and the timeline in which the viewer/reader experiences the story. So in that sense, the “first time” is the way things were in Chapter One.
I don’t know whether we have any reason to suspect that there may be similarly more than one timeline to Reality.
Robert Forward, a physicist vwho actually demonstrated some SF concepts, and proposed others, and who was also a science fiction author himself, famously stated that he didn’t believe in the Grandfather Paradox, and wouldn’t until he saw a mathematical proof of it. He wrote his own Time Travel novel, TimeMaster, to show his impressions of things – there is only one “Time Line”, with no “branches”. If you go back in time, you have contributed to the State of Things As They Are – your actions in the past define the past, which is immutable. So, in his way of looking at things, you’re quite right, there is only the “original timestream”.
Other people take a cue from the Other Worlds view of Quantum Mechanics, and assume that if you go back in time and change things, you create a “new branch”, and if you travel forward in time you ebnd up in that New Future that you have changed. A lot of classic Time Travel stories take this tack, even if they didn’t think it all through beforehand. L. Sprague de Camp’s Lest Darkness Fall and Aristotle and the Gun are definitely of gthis type – the heroes go back in time (intentionally or not) and change the ghistory that they were familiar with. They clearly weren’t part of the past as they knew it, because they remember a past without their changes in it. Martin Padway in Lest Darkness Fall prevents the Fal of Rome, and gets to see its effects (he doesn’t have any kind of time machine, so he can’t go forward to what would have been his time and see the changes). The hero in Aristotle and the Gun does go back, and finds an America that hasn’t been colonized by Europeans, but has an American Indian nation running it. Clearly this is all very different from Forward’s “Everything’s all in one timestrweam” concept, and the time-line de Camp
's heros came from is clearly the “original” timeline. Certainly the one they exist in at the end of the story, which only exists because of the actions of the time travelers, couldn’t be the “original”.
This brings up that Grandfather Paradox* – if they changed the past, then the timeline they came from couldn’t possibly exist, so they themselves wouldn’t be the same, and probably wouldn’t even exist, so they couldn’t go back in time to produce the existing timeline. It’s incompsatible with Forward’s model. The movie The Terminator sidestepped all this by having Reese (the time-travelling Michael Biehn character) saying “I Don’t Know Tech Stuff”. But the usual way to “explain” this is to say that one has created an alternate time stream with that change made in the past, and that two different futures (at least) now exist, somehow. It’s not really all that different from the “many worlds” hypothesis, and people don’t usually think about it beyond that.
Then, of course, there’s that idea of the guy who goes back in time and gives himself the plans for a device (maybe even a time machine), or even the device itself, leading to the question “Where did it come from in the First Place?” An interesting idea, once. It’s been done to death. Arguably the best use (but not the first) was Heinlein’s All You Zombies.
And then there’s the idea of people going back multiple times to change the past, either going back themselves, over and over (Robert Heinlein’s By His Bootstraps is probably the gbest of these, but there are LOTS of others). Again, in these stories, there’s an “original time line” before anybody from the future started meddling in the past. None of these stories are compatible with Forward’s “only one timeline” scenario.
So, if you consider only Forward-type scenarios believable, then I understand your confusion – there is no “original time line”, because there’s only one timeline. But in the other scenarios there clearly is an original timeline. In the example you choose, the Forward scenario works perfectly well, up to a point – Reese’s going back in time was “always” part of what happened, and Connor sent Reese back in order to get himself conceived. But it’s also believable that the Terminator existed in a “multiple timeline” scenario, in which a John connor in an “original” timeline, who wasn’t Reese’s kid, sent reese back to save Sarah Connor from the Terminator to prevent the future that he lived in, in which Reese impregnated Sarah with John Connor. This caused a branch in the time stream, in which we thus now have a John Cobnnor with a different father.
The thing is, the Terminator films all assume that it’s possible for Time Travelers to change the past – otherwise there’s no point in sending either reese or the Terminators back in time. So they must by “multiple timestream” stories, which brings us back to the question of who the hell John Connor’s father was in the “original” timestream.
I’m sure this is all covered to death in TV Tropes. But we used to think and write about these things before TV Tropes existed, you know. Look up Time Travel in The Encyclopedia of Science Fiction, or Larry Niven’s essay The Theory and Praxctice of Time Travel, or any of a number of other places.
My first sig line was the ministory:
Of Course, said my Grandfather, pulling a gun from his belt as he stepped from the Time Machine, there’s no paradox if I shoot you*!*
take the scenario, if you go back in time [from today] to kill Hitler and succeed, then why did you go back in time? If Hitler died in 1930something, then he didn’t exist and no one had any reason to go back in time.
If you succeed in travelling back in time and if you killed Hitler before WWII, then history becomes a very very different place, and all the millions of people who died as a result of the war would be put back into existence, and all the people who were born after the war (when the population sought to rebuild itself) would be erased - which might well include yourself, or the person who developed time travel. Tricky.
Unless, of course you go back in time to assassinate him during WWII, which doesn’t stop the war, or remove the Death Camps, therefore leaving the time line relatively undisturbed. But what would be the point in doing that?
Who knows, maybe someone went back in time already and Hitler was the result of their pesky meddling!
There are many SF variations on what might happen if you go into the past; part of the point of time travel stories is to speculate on paradoxes. Some ideas have been:
Alternate timelines (very common).
You are prevented from doing anything that changes the timeline (Fritz Leiber’s “Try and Change the Past” is a variation – you can change it slightly, but the net result is that it’s unchanged).
You can change the past, but only in minor ways (there was a Twilight Zone episode where they try to save Lincoln. They fail, but their actions inadvertently make a servant a rich man).
The slightest change causes major variations (Bradbury’s “A Sound of Thunder”).
You can change things as much as you want, but it only affects* your* timeline (Afred Bester’s “The Men Who Murdered Muhammad”)
The past is built on a consensus; your actions won’t change the consensus reality (implied in George Alec Effinger’s “The Bird of Time Bears Bitter Fruit”).
The author doesn’t try to explain it logically (Lester Del Rey “. . . And It Comes Out Here” and David Gerrold’s The Man Who Folded Himself). Del Ray’s character basically said “I can’t figure it out, but it happened so I have to go back”).
Anything you do in the past is already part of history (The Anubis Gates by Tim Powers).
That’s just a few off the top of my head. The point is that dealing with the paradoxes is part of the fun in writing and reading time travel stories.
I think the first Terminator film by itself is consistent without having an original time line, that the events of the past were always as they were and the time travelers actions were always part of that past. That the people or machines from the future who sent them back may have believed they could change the past doesn’t mean that they actually could. It only gets complicated when the sequels are put in because they actually do manage to change the future from which the terminators were sent back because in that future skynet was created using the technology from the original terminator but most or all of that research was destroyed and judgment day was pushed off. But even then, maybe it’s some sort of more complicated loop that includes sub-loops; after all, the T-X and T-101 interaction were integral in ensuring that John Connor survived; had they not gone back, he never would have survived Judgment Day.
One other possibility that may work in solving this sort of scenario is that perhaps the timeloop creates some sort of infinite feedback. In some “original” timeline, someone went back for some reason and created a small change, and each subsequent loop grew more and more dependent on those small changes until it eventually converges on being fully dependent on the changes that the loop itself creates. But since there’s still only one timeline there never really was an “original” one to begin with.
So going off of that, I could see it going something like this. Someone goes in the past and brings future technology with them, as the loop progesses the technology they bring back gets more and more advanced and it eventually leads to creating a self-aware technology that is fully dependent on it’s only technology leading to its development. So this technology realizes its own existence depends on this and makes an effort to perpetuate the loop getting more and more advanced. Somewhere someone tries to stop it which means on the subsequent loop it is aware of this attempt and sends back a machine to stop it. This feedback gets worse and worse leading to contempt and eventual war and it tries to go back and kill the leaders. Eventually over countless loops it works out that one of the guys fathers someone who ends up helping in the future. This person, aware of this from his mother, makes the effort to ensure he exists and it makes him more and more important in the timeline because his mom is able to pass on more and more valuable information about the eventual future. And this eventually converges on the timeline we see in the Terminator films.
As has been discussed, the part which I see that you are missing: the past, as we perceive it, has already happened. If one were to go back in time, one of two possibilities will happen:
The past changes as a result of your actions
It doesn’t
Take the standard trope “go back to 1930s Germany and kill Hitler” scenario, for example. You arrive in that time period, find your target and kill him. WWII never happens. Why did you go back in time, then, since this person never caused the global atrocities which motivated your time travel? Ah! but you “remember” that, when he lived until the end of WWII, many people died as a result of his atrocities.
So he either lived until 1945, or died in the 1930s. You “remember” both timelines. Those people in the “present”, at the time you went back, “remember” Hitler as a major figure in WWII. Those people in the 21st century after your sojourn into the past, will not “remember” WWII the same way, if it happened at all.
Ursula K LeGuin’s excellent story, The Lathe of Heaven, explored a similar theme—that by “effective dreaming”, the protagonist changed reality, and that everyone “remembered” the altered past, but that the doctor who was “coaching” him also “remembered” the past as it was before the effective dream.
There is a class of time travel fiction where the “travel” consists of the ability to view the past, but not to interact with it in any way, or to appear as an unseen “phantom”, who can freely move through the actual environment of the past, but cannot interact with it at all. In these cases, there would be no paradox, as the time traveler would not be able to effect any changes to the timeline.
Any scenario whereby the time traveling hero can, in theory at least, change the course of history, implies that there must have been an “original” timeline, which has now been changed to the “new and improved” timeline.
The driving force in stories of this kind is usually the desire for the protagonist to return to the the ‘original’ timeline. It may only be original in his perception, in other words, the first timeline that he can remember. As timelines change, or the one timeline changes, he may have a perception of new timelines, but no one else will. The universe doesn’t appear to be changing to them. So the term ‘original timeline’ could be called a literary form of identifying the first history that a time traveler can recall.
“Thudlow” is a butt-head!" (Not really, okay? Just an example)
Oh, fuck! I wish I hadn’t said that! Let me just hit this little button on my wrist and set it back to 2 minutes earlier, and wait…
Then I’ll say, “Thudlow is a bud and can do no wrong!”
Let me do that… right … now!
click
But Thudlow is detained in traffic and doesn’t arrive at the exact time you insulted him.
Now what?
If you really want to change history and have the power to do it, then you REALLY have to be there at the pivotal moment, right or wrong?
But what is the pivotal moment?
Hitler’s daddy suddenly thinking that Frau Schickelgruber looks pretty good at “closing time”, and sinking 3 drunken inches into her thigh instead of where it’s supposed to go??
There is no pivotal moment.
What’s happened is gone.
As “Brother Dave” Gardner once said, “You can’t do anything AGAIN!”
Once it’s done, it’s gone.
However… Wasn’t it Jules Verne who wrote about going to the moon?
And didn’t we?
And wasn’t it Jules Verne who wrote about time travel?
We haven’t managed that one yet, but who was it that said something like “To conceive of a purple cow, is essentially to have met one.”?
Some thoughts from what’s left of my mind. Take nothing I wrote seriously, and please don’t challenge me, because I probably won’t even be able to defend my position.
On the “circularity” idea…
There was a little throw-away line in one of the Star Trek movies (“The Voyage Home” I think, where they go back to 1980’s-era San Francisco to collect a whale). Needing some 20th century money, Kirk and McCoy go to a pawn shop and pawn McCoy’s eyeglasses. McCoy says wistfully, “Those were my grandfather’s glasses”. Kirk says: “They will be again.”
I’d have to imagine you’d be plenty insane and pretty positive you’re bound for “greatness” based just on the number of strangely garbed people who keep showing up trying to kill you or prevent you from being killed.
And everybody thought Hitler shot himself because of his imminent defeat, when all he ever really wanted was to be an artist. Why couldn’t time travelers have just left him alone? The art of his later years in the original timeline wasn’t that bad.
And, if taken literally, that is a paradox, as the glasses should decay on each return trip. There’s an easy fix, though: have someone somehow restore them each time.
Y’all have already hit on the problem with not having an original timeline. I in fact posit that, even in situations where an original timeline is not shown, there really had to be one. For example, in the Doctor Who episode Blink, it’s not possible that the Doctor was just reading the questions he was going to ask. He must’ve originally asked questions from his own knowledge, and then those questions were written down in a hypothetical original timeline, and then sent back so that he could copy them. Information can’t arise from nowhere–all effects must have a cause, or else you have an ontological paradox. A hypothetical original timeline takes care of this quite nicely.