Time Travel Thursday: Theories of Time Travel

Posted November 7, 2013 by Stormy in Books / 12 Comments


In honor of Sci-Fi November, I’m bringing Time Travel Thursdays back! At least this one. I might do a few more if I can swing it, but often Time Travel Thursdays take me the longest to write, and I’m doing NaNoWriMo as well, so. . . we’ll see.


And what is today’s Time Travel Thursday, you might be asking? Well, I thought I’d talk about the ins & outs of time travel, as much as I can understand it. See, even though time travel is fictional(as far as we muggles know. . .), not all time travel stories use time travel in the same. Time travel in say, Doctor Who, is different from time travel in the Ruby Red books or Back to the Future(well, I’m guessing there, as I’ve never seen it). So today, class, we’re going to talk about Theories of Time Travel. And bear with me, ‘cuz this stuff gets complicated and I’m not that great at science to begin with.


So in order to understand some of these theories of time travel, I have gone down a Google rabbit hole and I have a headache from trying to wrap my head around some of these theories. Because while time travel may be fictional, real physics do often come into play in these theories. The wikipedia page on time travel does quite well delving into the physics theories if you’re interested, but I want to focus more on timeline theories–or rather, when we use time travel as a device, do we used fixed or fluctuating timelines? So, on to our theories/ideas about timelines.

1. The Fixed Timeline

As much as I can understand it and condense it, the idea of a fixed timeline is this: Things happen, but nothing ever changes from the original. Things were MEANT to happen as they did, and no matter how much you muck around in time, you’re not going to change anything. You can’t kill Hitler, you can’t start WWIII in 1975. According to Wikipedia(and yes, Wikipedia is my main source because it’s the only one I can find that doesn’t make me want to weep from how complicated it all is):

The principle states that the timeline is totally fixed, and any actions taken by a time traveler were part of history all along, so it is impossible for the time traveler to “change” history in any way. The time traveler’s actions may be the cause of events in their own past though, which leads to the potential for circular causation and the predestination paradox

This principle comes from Novkiov’s self-consistency principle. The self-consistency principle has quite a bit of parts and seems quite complicated, but you get the basic ideas. However, because time travelers may be the cause of actions in the past, sometimes in a fixed timeline time loops happen. Or rather, just the circular motion. The person who goes back to the past influences everything, but the way the past happens is what leads that person to NEED to go back to the past, etc. It goes round and round like a merry-go-round. The Predestination Paradox page explains it well, but the gist of it is this:

A predestination paradox (also called causal loop, causality loop, and, less frequently, closed loop or closed time loop) is a paradox of time travel that is often used as a convention in science fiction. It exists when a time traveler is caught in a loop of events that “predestines” or “predates” him or her to travel back in time. Because of the possibility of influencing the past while time traveling, one way of explaining why history does not change is by saying that whatever has happened must happen. Time travelers attempting to alter the past in this model, intentionally or not, would only be fulfilling their role in creating history as we know it, not changing it. Or that time-travelers’ personal knowledge of history already includes their future travels to their own experience of the past

And as complicated as this paradox can be to wrap one’s head around, I think in the long run fixed timelines are less complicated as fictional devices. They can lead to some pretty awful things happening, but everything happens the same way. When I think of this time travel theory, I think of the third Harry Potter book, The Prisoner of Azkaban. The time-turners allow the trio to save Buckbeak, but they had already done it from the beginning, they just didn’t know it. There was no way they would have failed, because they already succeeded.

2. Flexible Timelines

Wikipedia calls this one a “plastic” timeline, but I like my word better because I think it describes it better. BASICALLY, time is wibbly-wobbly and can be influenced, though often in different ways. I think, having read over all the major timeline theories, this is the one that may lead to some of the most interesting situations but also causes my head to hurt the most.

With a flexible timeline, you can change the past as you want, but it may affect the future in ways you didn’t think of before. Think “Butterfly Effect” type change–often chaotic and seeming randomly, but each action is a tiny string on a timeline, and if you move one around, it changes the entire order. How hard it is to change the past can change depending on how this timeline is used.

It’s interesting that I find this one the easiest to explain on paper but when I start trying to think of movies/books/TV shows that employ this one, the timelines make me SO confused. Whereas it’s so difficult to explain a fixed timeline, but it does really streamline a story.

3. Alternative Timelines

Okay, so I think alternative timelines is my FAVORITE way of time travel. Again, the simple explanation of this, from the Wikipedia page:

In this version of time travel, there are multiple coexisting alternate histories, so that when the traveler goes back in time, he/she ends up in a new timeline where historical events can differ from the timeline he/she came from, but his/her original timeline does not cease to exist (this means the grandfather paradox can be avoided since even if the time traveler’s grandparent is killed at a young age in the new timeline, he/she still survived to have children in the original timeline, so there is still a causal explanation for the traveler’s existence). Time travel may actually create a new timeline that diverges from the original timeline at the moment the time traveler appears in the past, or the traveler may arrive in an already existing parallel universe (though unless the parallel universe’s history was identical to the time traveler’s history up until the point where the time traveler appeared, it is questionable whether the latter version qualifies as ‘time travel’).

And in case you don’t know, the grandfather paradox is the paradox that would occur if you were to go back and kill your grandfather in a timeline at a point that occurs before he has children of his own. Your grandfather is now dead, so how can you be alive if he hasn’t had kids himself yet? But you’re the one who killed him? And thus, the paradox is born.

The alternative timelines is basically, from what I understand, splitting timelines and realities. Each time you travel through time and enact some sort of change, you create a new timeline. Sort of like multiple revisions of the fabric of reality. Of course, then you have to deal with alternative realities and split timelines and CHAOS everywhere! though it may not seem like it.

WHEW. Okay, guys. That was a REALLY brief introduction to the physics and theories of time travel. There’s a LOT out there if you’re interested. And as I think is obvious throughout this post, it hurts my head too, which is why I really over skimmed over a few types of timelines. But there’s a lot out there about the nature of time in stuff, so if you’re interested, the Wikipedia page I referenced throughout really IS a great place to start, despite all the things you sometimes hear about Wikipedia, and the references section on that page. And if you’re looking for a list of books with time travel, here’s just a few. I haven’t read them all, but should be a pretty good sampling of different kinds of timelines/books.

Time Travel in Literature

  • A Christmas Carol(of sorts. . . Scrooge travels back to his past with the ghost & to his future as an observer ONLY)
  • A Connecticut Yankee in King Arthur’s Court by Mark Twain
  • The Time Machine by H.G. Wells
  • “A Sound of Thunder” by Ray Bradbury
  • Time After Time by Karl Alexander
  • Doomsday Book by Connie Willis
  • Timequake by Kurt Vonnegut
  • To Say Nothing of the Dog by Connie Willis
  • The Time Traveler’s Wife by Audrey Niffenegger
  • Ruby Red by Kerstin Gier

And if you’re interested more in the theories of the plausibility and “how-to” of time travel rather than timelines themselves, here’s a cool YouTube video I found about 10 Mind-Bending theories of time travel:

OKAY, I don’t know about you, but my brain is tired! So, if you’re a time travel fan, which of these timeline theories is your favorite to see enacted? And even if you’re not a huge fan, what do you think of these different timelines?

Tags: ,

12 responses to “Time Travel Thursday: Theories of Time Travel

  1. Bookish Recap: November 3rd – 9th | A Bookish Heart

    […] Chapteriosity shares six sci-fi books she hasn’t read. – Stormy @ Book. Blog. Bake. discusses theories of time travel. – Alix @ A Novel Idea says sci fi is not just a guy thing. – Tory @ The Sleeping Latte lists her […]

  2. Wibbly wobbly timey wimey!

    Time is one super confusing thing and you explained these theories really well =) I like the whole theory of alternate timelines too. Or darkest timelines… if you’ve seen Community you’ll know the episode I mean ;D

    Great post!

  3. I just finished Doomsday Book last night/early this morning. This book made me feel all the feels. I really like the idea of being able to travel in time, but you are unable to go to a point in time and make major changes.

  4. Wow, this is so interesting! I’m actually listening to the audiobook of 11/22/63 by Steven King, which is another book about time travel and I’m really like it so far. I love the idea of having time travel in a novel, and I really want to read more that involve it. I think that the different theories are all really intriguing, and I agree that the multiple realities thing sounds really cool.

  5. I bloody love time travel and this post seems like it was pretty much made for me. All of the different theories fascinate me and it’s just such an awesome idea, isn’t it? You should definitely read Outlander by Diana Gabaldon (review below!) if you’re looking for another time travel read. It’s one of my very favourite books.

  6. Ooh, interesting post, Stormy! One of my favorite shows, Continuum, seems to be employing a combination of 2 and 3 actually. Well, it’s more like the characters THINK it’s like #2, but then it kind of SEEMS like it’s actually #3? We don’t know! It’s fascinating!

    And speaking of time travel, I just watched an episode of Star Trek last night that was pretty interesting. So this guy keeps getting hit by a singularity that pushes him about 5 hours into the future, for like a minute, then brings him back to “now”. Each time he’s pushed into the future, he can actually see and interact with his future self. *I don’t want to spoil the episode* but in the end, something goes wrong and in his final time jump, he ends up having to send Future Him back to “now” to take his place. It’s so weird. But I can’t figure out what category that would fall under! Thoughts?

  7. *applause applause* Excellent explanations of the theories! The fixed timeline is the easiest one to understand, because like you said, they’d done it already. (Harry casting his Patronus because he knew he could do it because he already did.)

    The alternative timelines are perhaps the most entertaining, and it’s with the paradoxes that I think most authors and readers get jumbled. If you are able to change events in a flexible/alternative timeline, there should be consequences. Things in the future should change at least a little … right?! Augh too early. It’s only 9 Am and I haven’t had enough coffee!

Leave a Comment!

This site uses Akismet to reduce spam. Learn how your comment data is processed.