Hi guys! This is going to be my first real attempt at a blog post. This is going to be a little unusual as posts go on this blog, as it’s not a short story or anything, but a bit of a non-fiction ramble. Some, who I guess you could describe as “experienced”, would argue that a more professional first post should serve to set the tone of the site, giving readers an idea of what future content will look like so that they can make an informed decision about whether to return. To which I say “Professional? No thanks!” Wouldn't you much rather tap into the demographic that prefers as patchwork an experience as possible? Why lure in potential views with consistency when you can deter them with delusional incongruity? Everyone knows all the best music is made up of dissonant notes.

With that, time travel!

Where we’re going, we don’t need roads: Time Travel in Fiction, Part I

People complain a lot about works of fiction that “don’t do time travel right”. As far as I’m concerned you might as well complain that Harry Potter doesn’t do magic right, or that Star Wars doesn’t do faster-than-light travel right. Time travel is an inherently fictional concept. Although you do get the occasional physicist speculating about it (who knows, it might turn out to be possible – I don’t especially think so, but maybe that’s for another time), how the causality of the whole business would actually work is totally up in the air. There’s no way of knowing whether it’s Back to the Future or Interstellar that has it right. Probably none of them are strictly correct; that would be like Shakespeare inferring general relativity in his writing about starlight. So why bother criticising one work of fiction or another about the accuracy of its portrayal of time travel?

Anyway, with that rant out of the way, here are some thoughts on exactly that.

In movies, books and television, time travel usually fits one of three different models. There’s the Novikov self-consistency principle, the branching timeline model, and the single amorphous timeline model. Here’s a bit of a rundown of each one:

In a Single Amorphous Timeline, as I’m calling them now, the future is always in flux. This is the model you see most commonly in time travel fiction, as it’s the way people tend to assume it would all work. In a SAT, when you travel back in time and change events, the future is simply rewritten. When you return to the future, you get to see how everything has changed. Back to the Future uses this, as does Looper. Doctor Who is somewhat inconsistent in the way it treats time travel, which fits pretty well with the show’s utter lack of continuity. Don’t get me wrong, I love me some Doctor Who, but 34 seasons and god knows how many writers will do that to a show. However, in general, it seems to subscribe to the SAT model. And, having possibly insulted Doctor Who I am now going to run to an undisclosed country to avoid the hoards of rabid Whovians that are now coming to sacrifice me to their life-size statues of Matt Smith.

A Branching Timeline uses a multiverse. That is, there are parallel universes branching from the original. When you travel back in time, you create a new parallel timeline that lives alongside the original reality. You change the future of the new timeline, but the original remains untouched, apart from the fact that you’re no longer there. There isn’t usually any way of returning to the original timeline, unless there’s some fictional way of hopping between timelines (which would itself just create a new timeline, I guess). The novel Rx: A Tale of Electronegativity does this to a certain degree by keeping your body in the normal timeline and sending a copy of you into the past (that book does some really cool things with time travel – see the bottom of the post for more information). Terminator seems to be a BT (although the first movie hints at a Novikov cosmology), as does Star Trek; in fact, the two reboot movies, Star Trek (2009) and Star Trek into Darkness (2013) take place in a timeline that branches away from the original when Nero arrives and kills Kirk’s father. However, storylines from the television series seem to demonstrate both SAT and Novikov characteristics, so, like Doctor Who, Trek lacks a unified time travel mechanic. I think the danger of Trekkies coming to hurt me is slightly less, but just in case...

From inside of one, it might be difficult to tell whether your universe is a SAT or a BT. The only difference to an internal reference frame is this: in a SAT, the time traveller may experience changes to itself because of actions it takes in the past. Marty McFly starts vanishing because he accidentally stops his parents from meeting; Bruce Willis gets new memories as Joseph Gordon-Levitt (his past self) takes a different path.

On the other hand, in a branching timeline, the time traveller remains unaffected by any changes it makes. I can shoot my past self in the head and I won’t suddenly blink out of existence, because I now inhabit an alternate universe to the one I sprang from. Provided I can dispose of my body, I might even be able to take over my past self’s life.

By contrast, it’s pretty easy to tell if you’re in a Novikov universe, because nothing you do ever changes a thing, which I imagine would be frustrating. The Novikov Self-Consistency Principle, named after Igor Novikov (who was an astrophysicist who thought about closed timelike curves a lot), is basically that even if you travel back in time, there’s actually no way of changing the future. By travelling back in time, you will always end up creating the conditions that led you to travel back in time in the first place. A good example is Harry Potter and the Prisoner of Azkaban. Harry believes he is seeing his father fend off the Dementors, before he loses consciousness. Later, he and Hermione travel a few hours back in time, and Harry ends up being the one who fends the Dementors off himself. His past self mistakes his future self for his father. Harry was always the one who did it, creating a sort of causal loop. You see the same thing in Interstellar (2014), where Cooper receives a message from an “alien race”, which later turns out to be from himself in the future.

Although it always seems pretty neat (I found myself going “Oooooh!” when I first read Azkaban), the Novikov principle has troubling implications for free will. It seems to mean that your actions are set in stone, no matter what you actually intend to do. So there’s that.

So there you have it. Time travel can be a little tough to get your head around, and those are the ways fiction has used to make it a little easier. Personally, the branching timeline model is the most appealing to me.

Stay tuned for my next post, which will explore a little of the actual theoretical science behind time travel. See you next week!

On to Part II: Timey-Wimey Stuff

Appendix

A list of some of the time travel fiction I can think of, and where they fit in:

Novikov Universes:

· Harry Potter and the Prisoner of Azkaban – A great book, and one of the best Harry Potter films. Maybe you should watch all of them. Heck, read all the books while you’re at it, too.

· Interstellar – Christopher Nolan’s latest, all about wormholes and black holes and all sorts of holes. I really enjoyed this movie when I saw it, and I’d definitely recommend it. There’s plenty of physics talk that’ll get anyone with an interest excited.

Single Amorphous Timeline Universes:

· Back to the Future – Nothing beats a classic. Parts II & III are a little weaker than the original film, but that movie still holds up fantastically.

· Doctor Who (sometimes) – I started watching this when it was revived in 2005, and loved it. I’ve gone a bit cold on it lately, and the quality of the show is wildly inconsistent, but I think it’s worth checking out the seasons 2005 onward. Maybe it’s even worth delving back into its long, long history if you really want to chew up your remaining years.

· Looper – A great movie that came out in 2012. Far from being a standard sci-fi film, it explores some pretty deep morality and turns into a human drama, albeit with time travel and some pretty excellent action scenes.

Branching Timeline Universes:

· Star Trek – My introduction to Star Trek came from the 2009 pseudo-reboot directed by J.J. Abrams, which had an act of time travel cause the birth of a new timeline where everything is shinier and lens flarier. It’s pretty great. I’ve gone back and watched some of the older stuff since then. There’s some excellent Trek, and there’s also some pretty mediocre Trek.

· Terminator – The first two films are just excellent; Terminator 3 is passable; skip Salvation if you can help it.

· Rx: A Tale of Electronegativity – A great little sci-fi novel by Robert Brockway, who also happens to write for one of my favourite websites, Cracked.com. It’s about a society that’s addicted to time travel, and it’s as funny as you would expect from a Cracked writer. You can get it as an ebook on Amazon.