Welcome back to the Retromash Time Travel Week. Yesterday I looked at several different methods of time travel used in popular culture and sci-fi. Today I’m taking a bit of a closer look at some of the cliches and tropes that are regularly used in these movies and TV shows and asking questions about some things that arise from them. Some of them are just tropes that can help move the plot along and others are fundamental tenets of time travel which merit proper discussion.

Photo from http://www.sarednabworldprops.com

The best example of this is Marty McFly’s family photograph in Back to the Future. It doesn’t really make much logical sense. After all three of them disappeared from the photo would we be left with a blank photo? Who would have taken a blank photo of that wishing well? And why do the people disappear in the order starting with the oldest child? If the oldest child doesn’t exist then surely none of the siblings exist? And also why would they only disappear gradually? But obviously the reason for it all is that it’s a great visual metaphor for Marty’s existence being in peril. It shows you the progress he’s making towards either self-annihilation or getting his parents back together.

Let’s move on to one of the main ones in terms of plot cliches. Going back in time in order to change the future (i.e. your present). This is regularly raised in movies and I’m not sure there is any movie that deals with this that does not mention the words ‘killing Hitler’. So the premise is that you go back and change something and then when you return home your present is a much nicer place. But on the flip side there are many movies that cannot stress enough that you’ve not to change anything in the past because the tiniest change could be catastrophic for the future. And if you look at it from one perspective that makes perfect sense. The world is such a chaotic place that any slight change along the way could have a ripple affect that could affect who you or ancestors meet, or what important inventors did in their careers, or who became world leaders and started or ended wars. If you travel back and change something then either it somehow changes everything from that point on when you return or it creates multiple timelines or parallel universes. The old argument about if time travel was possible then why haven’t we seen anyone from the future is valid here too. If people have been travelling back from the future and presumably doing little things that affects everything then how do we all have a complete collective memory. For example if someone travelled back to the mid 80s and changed something that affected the whole world, would I (and all of us) then relive our lives again from that point on? I would have to live it again in a linear way because I have memories right now of every day from that point until now. And the fact that the person is coming from the future means that I had already lived a life. So them coming back and changing stuff caused me to actually live my life again from that point on. And if lots of time travellers are travelling back then everything has to be replayed again every time. So the whole essence of time in the whole universe is scrubbing back and forth every time a time traveller goes for a little ‘time vacation’? My fingers and head are both hurting after writing those last few lines. Again it brings me back to parallel universes. That’s my default answer to any complicated time travel question. Not because I understand it any more but just because it seems to be an ‘easy explanation’ for certain things.

So this leads us on to a specific result of the above point. After you have changed a few things in the past (whether inadvertently or on purpose), you return home in the present and some things have changed. I’ve never really understood how this can work. It can make the time traveller a real fish out of water when they get home. Here are some examples. In Back to the Future, Marty returns home to a family that has suddenly gone from arguably working class losers to middle class successes. But he hasn’t lived that life. He hasn’t been brought up that way. Everyone else is wearing fancy clothes and he’s wearing the same clothes he had on at the start of the film. He won’t have all the memories of the childhood things you do on family holidays and Christmases together. He is basically completely alienated from his family because he is a different person from a different life. And from the family’s perspective I can only assume that their Marty has suddenly changed into a Marty from an alternate universe who is all of a sudden acting all strange. Or did that new timeline just suddenly burst into existence? And if it did then what would happen if you went back in time from that point? How can you go back to see what happened earlier in a timeline that hadn’t existed? Jeez it makes my tiny mind hurt. Back to the Future is one of my all time favourite films but that ending has always troubled me.

Timecop also has a bit that I really didn’t like. Jean Claude van Damme is friends with his superior officer. They go to each other’s houses for dinner etc. But one time when he travels back he changes something which affects his whole work environment when he travels back to the present. Some small things like there is a new company name on the wall but some big things like his commanding officer doesn’t know that they used to be friends. This guy was his only ally in the plot of the film and also one of his only friends and now all of a sudden the superior officer hardly knows who JCvD is! Van Damme takes it pretty well but I’d be a bit traumatised.

Hot Tub Time Machine has something which is pretty cool but also made me think (spoilers here if you haven’t seen it yet). When Lou stays in the past and and makes lots of money, the rest of the gang travel back to the present and everything has changed. For example Nick is now a big music producer with lots of experience of producing tracks for big artists. But how is he supposed to walk right into that job and keep producing high quality music when he probably doesn’t know how to use the high end editing software (yep, I’m getting pretty anal here, but hey, these questions need to be asked. These are the sort of thing that can keep a retro blogger up at night!). When these people go back to their present they must almost feel like Sam Beckett after leaping into a stranger’s body in some ways.

A common trope is to go back in time to make yourself rich in the present day. I think you have to be very careful here. If you go back and change something massive like you become friends with Steve Jobs right before he starts Apple and somehow negotiate 50% of the company with him, if you then skip forward to the new future then things are going to be hugely changed in your life and you won’t know most of the new people around you in your new life. That’s my guess anyway. So you would have to be smart with maybe just investing in companies that you know will become big and put the money in a Swiss back account which you can access when you’re back in the present. Or alternatively find something that is very valuable in the past or that increases in value over time and bury it somewhere really safe so that when you are back in the present you can just dig it up.

Some movies go with the premise that you can’t change the future. That the future has already happened in the same way that the past has already happened. You therefore can’t change anything. “But what if you do this? Nope, you’ve already done that in your future. But what if I do that? Nope, that means you will have already done that. So what if I don’t do anything. Well, that means THAT’s what you’ve already done.” I find this fatalist approach frustrating and a bit depressing. In movies this is kind of represented in films like Deja Vu (slight spoilers) where you see glimpses of things during the film that don’t quite make sense when you see them first time round but then later on when Denzel travels back in time and tries desperately to change things and leave messages for himself etc you realise that this stuff was all done earlier in the film and therefore in the past before Denzel travelled back in time. It was already done and so Denzel was just destined to do it. It’s some kind of weird time travel chicken and egg thing and, although it can be clever in several movies (I think Twelve Monkeys maybe has something like this too) personally I don’t really like this form of predeterminism. I guess it only makes sense to me in some way if you argue that time flows both ways. But that gets very confusing and it’s just kind of depressing if it means that nothing we do has any point because everything has already happened.

I touched on it in the last point about having things which couldn’t have happened in the ‘past’ without someone coming back from the future to do it. But if time flows in one direction from past to future then how did this future person come back before the past was written? The most common example of this perhaps is in The Terminator when Kyle Reese comes back to protect the mother of John Connor and then finds himself becoming John Connor’s father. If he’d kept it in his pants then the resistance wouldn’t have had it’s leader to rise against the machines. Good job, Kyle. Taking one for the team there buddy. But it messes with your mind about what would have happened if he hadn’t had sex with Sarah Connor. John Connor would never have existed and so Kyle would never have been sent back in time, which doesn’t make sense.

This is the classic time-travel paradox. The time traveller goes back in time and kills his grandfather before his grandfather meets his grandmother. As a result, the time traveller is never born. But, if he was never born, then he is unable to travel through time and kill his grandfather, which means the traveller would then be born after all, and so on. I’ve never known why they go for the grandfather and not just the father. Perhaps because that leaves an element of doubt about whether or not you got to your father before he conceived you with your mother. But I guess it still counts if you go back and kill your father as a child or yourself as a child. But do you immediately cease to exist or do laws of probability kick in to somehow stop you from creating the paradox? There’s a fascinating page about this and other paradoxes on Wikipedia.

Here’s another thing I don’t get with time travel. I personally feel that the time traveller has their own timeline which they can travel back and forth in, which is separate from the ‘universe’ timeline. This one might be hard to explain. If the traveller goes from 2014 to 1985 to 1800 and then back to 2014 then that is their journey, in that order. If they literally press rewind on their own personal timeline then it would do their travels in reverse, so they would go from 2014 to 1800 to 1985 to 2014 and then backwards from 2014 as normal in their own life. It’s literally like pressing rewind on their own personal timeline. Or like going through the Undo History in Word or Photoshop. If they’re going back in time it’s relative from their perspective. It’s back in time on their own timeline rather than a master timeline. That kind of makes sense to me, because after all we’re not talking about immortals here who can just control time, we’re talking about normal people with a time machine. So they will be getting older themselves in their own timelines while they time travel. And on that point, what if they just repeat the same day over and over again in their time machine. They would get older themselves in real time but to everyone else’s perspective there will come a day when someone realises that they have suddenly become really old overnight. This doesn’t happen to Bill Murray in Groundhog Day because it is some kind of magical time loop for him but for a bog standard time traveller with a time machine they would age as normal. So my point here is that personally I feel that I would like to think that I could go back in time and do whatever I want with no fear of changing the future because to get back home I wouldn’t go forward into a new future but I would go back in my own timeline to the point when I was back in the present. I hope that makes sense. I think it does to me. ‘Heavy’ indeed, Marty.

There’s something fundamentally strange about two instances of one person existing at the same time. Particularly when they’re the same age. For some reason I find it easier to get my head round going back in time to see a younger version of myself in the 80s than I would visiting myself last week. It’s why it also makes me feel weird when Marty McFly returns to 1985 and sees himself getting into the DeLorean in the parking lot. There’s two Martys. Which one is the ‘real’ one then? Has an extra version of Marty been created? Like a clone? Shawn Robare from Branded in the 80s addresses this a bit in his awesome post about the other Marty McFly. Another very realistic and almost unnerving portrayal of this issue is raised in the movie Primer.

When people travel this way they normally become a duplicate of themselves, in the sense that they can go back and visit their younger selves. Their ‘current self’ and their younger self both exist and can interact. And supposedly if you touch yourself then the universe will explode or something like that. It’s like crossing the streams. There are a couple of questions this raises. You supposedly can’t create or destroy any matter in the universe. The exact same number of particles must always be present. So how can a new person be created out of thin air? But I guess your time travelling self could perhaps use up dark energy or dark matter or something like that (if a movie’s science consultant had to explain it). Then there is the question about the exact same particles occupying the same universe twice, although that could maybe be explained away by the fact that we actually regenerate all our particles every few months or years or whatever it is (maybe that’s a long shot though).

If this form of time travel was indeed possible wouldn’t you have to be really careful not to time travel to a place where you had been before? For example if you had been sitting in a chair for an hour then you shouldn’t just time travel back 30mins because you will end up just sitting on yourself, which would be weird. But by the same theory you shouldn’t time travel in any location where you think you might be there in your past time. You would always need to know that your past self wasn’t in exactly that location every time you time travel. Or alternatively find a new unique location to travel from every time you travel.

The best way of describing this one is to watch this totally awesome clip from Bill & Ted’s Excellent Adventure.
They need to get Ted’s dad’s keys so they just say out loud that they will time travel later on to two days ago and leave the keys right where they are now. They reach down and find the keys! Then Ted says they must remember to do that in the future otherwise this won’t happen, but then Bill points out that it already did happen! It’s total genius although they’re probably taking several liberties with the rules of time travel so I’m not sure the logic would hold up to further scrutiny.

When people stay in another time period for any length of time they are always shown to be in full health. They never seem to become ill due to not having the right antibodies to handle the current strain of the cold or flu going round at that time, or alternatively you could bring a strain of a bug with you that would wipe out an earlier civilisation. This entertaining video has a great list about why time travel just wouldn’t be that great.

As I mentioned before, any time I come across any kind of paradox or question mark around time travel I just think that the only way round it is if a parallel universe or alternate timeline is created every time, and if the time traveller wants to return ‘home’ they just have to go back in time in their own personal timeline.

In summary, I feel that the biggest question marks with time travel films are about how the future is affected by actions in the past. There are several theories that say time travel to the past could be possible but the big question is what is the ‘state’ of the traveller. If time for the whole universe is reversed then we’re not really aware of anything happening, but if it’s relative to the time traveller and they just jump to a point in time then the consequences depend on if he is regressing through his past life, or if he is being a voyeur or if he is a duplicate of himself etc. And to be honest, as we don’t have any true scientific answers for any of these questions I think that the plethora of different interpretations in time travel movies is what makes it such a rich and vibrant genre.

Tune in tomorrow when our Time Travel Week continues with a look at the different kinds of Time Travel Vehicles used to traverse the annals of time. Which is the most sensible way of travelling through time? Which is the most random? And perhaps most importantly which is the coolest?

#timetravelweek

• Tweet