With Tenet having come out the past few weeks, I’ve been thinking of my favorite time travel movies. I’m not entirely sure if the new Nolan flick is time travel in the traditional sense, as it seems that people travel in reverse, real-time, but I still wanted to talk about it, so let’s see how it goes.
All time travel stories seem to subscribe to one of three theories on how time travel, if it could work, would work. Below is a cool graphic, that I’ll be expanding on.
This is my favorite form of time travel, because it’s the only one that holds up to scrutiny according the laws of physics that we currently understand. Everything that has happened, will happen because it has. Also, things that will happen, will happen regardless of your actions. This is the least dramatic of all time travel, because there is no way you can change the past or the future via your actions. My first foray into the idea of time travel, if I remember properly, was in Harry Potter and the Prizoner of Azkaban. In it, they try to save Buckbeaks life, by going back in time, and when they do, they realize that they were warned of the executioners arrival via themselves, in that moment. Not only that, but when they initially saw Buckbeak’s death, they didn’t actually see him, just heard the sound of the axe chopping, which they later realize was through a pumpkin out of frustration, meaning they had always succeeded. They went to the past, and didn’t change any outcomes, but instead ensured what happened will happen, as would always happen. They saved the day, but didn’t change anything.
In Tenet, the time travel is fixed, and the characters travel in that fixed timeline, backwards. We see this in the trailer, when one character gets into a fight, and it’s clear that the person he’s fighting’s actions are influenced by that fight, but backwards.
Next, we have a the Dynamic Timeline. This is the basis of most time travel movies, because to put it simply, this is the one that you have the power to control, and meddling with it could cause problems. If you go back in time, you can prevent something that has happened, but in doing so, you could cause the future to change, so much so that you might even prevent your own birth.
The most popular version of this is in Back to the Future, where Marty McFly goes back in time, and almost erases his own existence. This causes a paradox, as he starts to vanish from reality itself.
This is the theory of time travel that is rising in popularity, especially in comic book movies. Whether it’s the Worlds of DC universe, with the Flashpoint movie (both Keaton and Affleck Batmans! Batmen?) or the Marvel universe, in Endgame when they took the Infinity Stones out of their time, and the upcoming Doctor Strange in the Multiverse of Madness. In both of these stories, they rely on the theory that every decision that is made in the world, splits reality into two parallel universes, wherein each of those decisions are made, and so there are infinite parallel universes, depending on every single combination of possibilities over all of time. So whenever you go back in time, you are actually going to that alternate reality where your actions were the truth. This is, in effect, similar to the Fixed Timeline theory, it’s just that there are multiple Fixed timelines. You aren’t only travelling in time, but also in space, between the multiverses.
Lastly, we have the logic of Doctor Who, which is a mix of all of these. There are times when The Doctor goes back in time and changes history, and there are other times when history happens the same way, regardless of his involvement. The show calls these “fixed points in time”, or moments that are too important to be changed, and will happen no matter what you do. The show used these fixed points primarily as a way to teach about history, as the shows original intent was educational.
In The Umbrella Academy, we see an almost Whovian style of time travel with the Commission, who ensures that specific moments in time play out the way they are supposed to. They find out that different events might be changed by specific people doing things a certain way, and they must travel through time to kill the right person, to ensure that the event should happen. Of course, the addition of problems in time, that they find out over time, doesn’t make sense by traditional time theories. At one point, they find out that the Hindenburg might not blow up, which is, in essence, a “fixed” point in time. Therefore Five decides that a butcher needs to die, so that his unhygienic son would take over the business, making the problem person unable from stopping the destruction of the airship. But why do they find out at that point that the problem person is a problem in the first place?
The answer is that time is just a “big ball of wibbly-wobbley, timey-wimey, stuff.”