Time Travel, DeLoreans and Grandfathers

 Perhaps I am biased, but I see Robert Zemeckis’ Back to the Future (1985) as one of the landmarks of American cinema, incorporating elements of science fiction, adventure, and comedy.  I have probably seen it 20 or 30 times during my life, and it is the movie that got me interested in science fiction, interested in playing guitar, and interested in movies in general.  The classic story follows teenager Marty McFly (Michael J. Fox), who is accidentally sent 30 years into the past in a time machine that mad scientist Dr. Emmett Brown (Christopher Lloyd) built out of a DeLorean.  In the year 1955, Marty runs into his parents and inadvertently prevents them from meeting, resulting in Marty’s mother (Lea Thompson) falling in love with Marty instead.  The rest of the film chronicles Marty’s quest to reintroduce his parents to each other, as well as find a way to get back to 1985.

            I think that my love for Back to the Future is apparent, but it is also important to note that the film requires a certain suspension of disbelief on the part of the audience.  Plots driven by time travel are difficult, and even though Back to the Future is a clever and entertaining film, there are numerous paradoxes and plot holes.  I remember that when I was younger, I would always argue with my dad about how Back to the Future did time travel “wrong.”  The same points that my 7-year old self was trying to make are discussed much more eloquently in David Lewis’s essay “The Paradoxes of Time Travel”, particularly in reference to the famous Grandfather paradox.  Lewis considers a character named Tim, who wishes to kill his own grandfather.  However, Grandfather died peacefully in his bed in 1957 when Tim was a young boy, so Tim builds a time machine and travels to the year 1921 so he can kill Grandfather himself.  Tim practices with a rifle and waits for the ideal conditions to fire on Grandfather, but Lewis makes the argument that it is impossible for Tim to kill Grandfather.  This is because, “Grandfather lived, so to kill him would be to change the past.  But the events of a past moment are not subdivisible into temporal parts and therefore cannot change.” (497).  Tim grew up with his Grandfather alive and kicking, which would create a contradiction if Grandfather was murdered by an unknown sniper in 1921.  Therefore, for the story to be consistent, Tim must somehow fail to kill Grandfather.

            Back to the Future treats time travel in a way such that the past can be altered, evidenced by several scenes in 1955, as well as when Marty finally returns to the year 1985 at the end of the film.  One famous scene from the 1955 portion of the film involves Marty performing a rendition of Chuck Berry’s “Johnny B. Goode” at his parents’ high school dance after he has successfully set them up together.  When another boy tries to dance with Marty’s mom, Marty begins to dramatically evaporate while he is trying to play the guitar.  Though this situation is obviously emphasized for theatrical effect, David Lewis would argue that this creates another logical contradiction.  In a given timeline, Marty can either exist or he cannot – it does not make sense for there to be a sort of “in-between” where he momentarily becomes a ghost.  When Marty returns to his proper time period, his family lives in the same place, but his house is completely transformed and his parents (particularly his father’s) personalities have totally changed.  Marty’s formerly unemployed siblings have steady office jobs and the formerly successful and arrogant Biff Tannen (Thomas Wilson) now makes his living washing cars.  At the end of “The Paradoxes of Time Travel”, Lewis maintains that the only way for this situation (as well as the Grandfather paradox) to be plausible would be if time travelers could create different branches, “separated not in time, and not in space, but in some other way.” (499).  Therefore, returning to the Grandfather example, there would be one branch of time where Grandfather lives and Tim does not appear in the year 1921, and there would be separate branch that diverts in 1921 when Tim arrives to kill Grandfather.  However, in this second branch where Tim succeeds, he has the potential to prevent his own birth.  Much like Back to the Future, depicting one branch of time where Marty’s parents are more successful than in another, at every point of Tim’s life there are two subsequent timelines, one where Grandfather lives and the other where Grandfather dies.  However, since the differing branches in this theory are not connected by space or time, this adds a whole new dimension to the concept of a time machine.  How would one be able to control which branch the time machine travels to?  Would one have to create an entirely new vessel to travel between branches?  In Back to the Future, it appears that the portrayal of time travel would have to be a lot less linear than it already is for the resulting plot to be logically feasible.  However, despite the paradoxes in the plotline, Back to the Future is extremely entertaining and my personal favorite film of all time, so I would obviously recommend it if you haven’t seen it.            

Not Like Back to the Future

Time travel has long been thought about by pretty much everyone at some point in their life.  Whether it be due to wanting to change things in the past or gain insight into what the future holds, time travel is, in our nature, an interest.  Being able to achieve time travel would open humanity up to countless possibilities, ranging from a greater understanding of the past to gaining the knowledge of the future.  However, despite all this, there seem to be some inherent problems with time travel in general.

In the 1984 film, Back to the Future, the main character, Marty McFly, meets the eccentric scientist Dr. Emmett Brown, and travels back in time in a tampered with Delorean.  In the past Marty accidentally causes his mother to prefer him over his would-be father, and so he must find a way to get them back together so that he and his siblings can exist 'back in the future'.  While this makes an entertaining film, as far as theoretical 'actual time travel' goes, it, and including the simple theory behind the movie's version of time travel, are simply not viable.

The first problem many people interested in time travel become aware of is the simple question: "if time travel were possible, then why haven't we met any time travelers yet?"  People like to disprove this argument, saying things like "people in the future wouldn't be interested in coming back to our time," or "there might be laws against interfering in the past," but frankly these are childish excuses.  Given the ever stretching possibilities of the future, it just isn't reasonable to assume that if time travel was possible in it's pure form that we would have seen no signs of it by now.  All it takes is one lunatic getting hold of the technology for us to have future-men parading the streets with absurd technology from the future.  This would seem to disprove time travel with relative certainty, but fortunately for potential time travel, the nature of time is just not that simple.

Many scientists and other such thinkers are still convinced that time travel is, or at least 'should be' possible.  David Lewis, for example, opens up with the line "Time travel, I maintain, is possible," in his article "The Paradoxes of Time Travel."  Similarly, in Richard Taylor's "Space and Time," he also holds that time travel, that is, the moving away from a  point in time, and then 'later' returning to it, should logically be possible as well.  But how can these things be possible given the problem I stated above?  To move forward in my discussion at this point I will use evidence from these articles as well as information I have learned from a scientific class on the subject.

Time and space are inherently related.  It has been proven that at incredible speeds, time will actually slow down.  While this is only significant for near-light speeds, it nonetheless proves that the two are eternally linked, and that we can think of time is a similar way to space, much as E=mc^2 proved that mass and energy are interchangeable.  So this means that if we were to be able to go at near-light speeds and come out alive, we could slow the time around us, while the rest of the world goes at normal speeds.  In this way, we could travel for, say, a year, but in the meantime the Earth could move ahead 10, 20, or any other amount of years depending on the speed.  Thus, when we returned to the Earth, we would have effectively traveled into the future.  While this method provides for no means to move into the past, it at least proves that moving along the timeline separately from our local world is possible.  We would just need a greater understanding of the nature of time to discover a way to move in the opposite direction.  Perhaps this could be done through great distances, in which we have seen that the velocity of an object, if moving towards or away from another object, slightly shifts the 'present moment' in which a person standing at either location would say is happening 'now' (this bit of science is wildly hard to get your mind around, so you'll just have to bear with me for the moment).  So then by moving away from Earth from many light years away, we could shift the 'present moment' into the past, and if we were then to cross the distance back to Earth while maintaining the same velocity (only possible due to the theoretical wormhole given our current understanding- remember, nothing can move faster than light speed) then we could arrive back any amount of years in the past.

So simple!

But this still does address the problem I previously mentioned, the "why haven't we met time-travelers" problem.  Scientists have come to the conclusion that assuming the forth dimension is time, then moving one step up from that, the fifth dimension would be alternate realities.  So then we would be in a timeline that is 'yet to discover time travel.'  Our timeline would move up to the point of finding a way to move.  Then, should someone go back in time, they would create a branching reality in which time travelers do exist, and things would move forward parallel to our current, no-time traveler universe.  Without this way of thinking, time traveling encounters the paradox that Back to the Future touches on, that if you changed the 'present' in the past, then the present you might have never existed to change it, or just never have had any reason to time travel in the first place.  The movie just lets the Marty, who is faced with not being born, start to fade out, to cease to exist.  While this works for the film's purposes, it is not reasonable for reality.

But I digress.  I myself believe that time travel is possible, it is simply now a question of application of our theories, which we currently do not possess the proper technology.

Loops and Loopholes in Time Travel

Robert Zemeckis’ Back to the Future (1985) displays an interesting interpretation of time travel. Throughout the film there are interactions with the idea of time, and traveling between time, causing inconsistencies to arise in the plot. Using Taylor’s ideas of space and time in comparison with Lewis’ theories of time travel, I will diagnose specifically what happened in the film.

In the film a young man, Marty (Michael J. Fox), is sent from the year 1985 to 1955, and becomes entangled in his parents’ lives, threatening his own existence. Due to the story being laid out in Marty’s personal time, we must first acknowledge that the beginning of the movie is the start and the end of the film is… well, the end. Throughout Marty’s personal time of about a week, Marty experiences character growth and ends up right where he left off in 1985 to pick up as if he had never left. This is hardly the point of concern. Where things get messy is the idea that 1955 is in the past, and then all of a sudden in the present (of Marty’s personal time) giving him control over his perception of what actually happened, since he never personally experienced 1955 himself.

            One thing we can all agree on is that at the end of the film, Marty’s life is back to normal, minus negligible changes considering the fragility of the space-time continuum. Sure he has a different car and his brother has a real job. Yea, his dad is slightly cooler than he was before, but ultimately it can be argued that the 1985 that we experienced with Marty is the 1985 that had happened anyways (before his travel).

            This can be reinforced by looking at several “loops” as Lewis calls them. Loops are essentially events caused by time travel whose explanation is explained only by time travel. This would be like if I go back in time and give myself a blue ribbon… only to give it to myself again and again and again. Several of these loops include Marty’s name, the African American man running for mayor, and Chuck Berry’s Johnny B Goode. The fact that these loops exist in Marty’s life much prior to (in his personal time) his travel to 1955 doesn’t prove the continuity of this time travel absolutely. Chrisholm and Taylor would argue that his interference with time is sufficient but not necessary to these events taking place. Something could have happened to cause these things to happen regardless of whether or not Marty got involved. The loop that ultimately comes together to prove Marty’s impact on the past is that Doc Brown (Christopher Lloyd) takes Marty’s advice in 1955 to wear a bulletproof vest. While it is still only sufficient, Doc hints that Marty’s letter had something to do with it.

Throughout the film, there are arguments to back up the possibility of a branching away from the “normal” timeline and reconnecting; however, there are several inconsistencies. While I will continue to ignore the changes after Marty’s return to 1985, I want to address a few issues. While Doc continues to refuse knowledge of his future due to the space-time continuum and how it can change the events that are to come, he did make a time machine. He also knows, because of Marty’s video, that he will live at least until 1985 at the point in which the video is made, yet he is afraid of falling from the clock tower. As a matter of fact, he shouldn’t care much about his future, because it is still uncertain to him, aside from his assured existence for the next 30 years. The only logical reason for him to care about changing the events of his future is because these events could interfere with what Marty and us would consider the normal chain of events. This all gets muddy, however he is slightly right in agreeing with both Lewis, Chrisholm and Taylor. Past events will remain past events and future events will remain future events, mainly because they are in someone’s past, even if that person exists in the future (Marty and us).

The most consistent aspect of the film is perhaps that Marty did not change, oddly enough. After his return to 1985 Marty’s life around him had changed, maybe only slightly. Still, would one not expect Marty to be different having been raised by such different parents? His brother and sister changed. Maybe his experience going back in time developed a change in his character. Maybe he learned some sort of lesson. Maybe this is exactly what the director intended! In dealing with such unknown and unexplored subjects such as space-time, time travel, and the understood continuum, could one expect the film to “get it right” without cracking the code of time travel itself? It is precisely these paradoxes and inconsistencies that make the idea of a time machine so difficult and foreign. After all, we had a time traveling experience of our own (cheesily enough). In the year 2013, we got to enter the world of 1985, then 1985’s interpretation of 1955, then 1985 again, and ultimately right back in our own present… our infinitesimally small concept of present.

Going Back to the Future with David Lewis

David Lewis in his essay The Paradox of Time Travel exclaims that ‘time travel is possible” (492). Before talking about the 1984 film Back to the Future featuring Michael J. Fox, Christopher Lloyd, and a cast of other great actors and actresses, I want to discuss Lewis’s thoughts on time travel and his philosophy that time travel is not an impossible notion. Lewis claims that if, “he can defend the consistency of some science fiction stories of time travel, then he supposes parallel defenses might be given of some controversial physical hypothesis” (492). In other words, Lewis knows that by defending the idea of time travel being possible he is also allowing other hypotheses to be possible, but Lewis exclaims that time travel should not be held as a scientific myth. The explanation of what time travel is precisely is a discrepancy between time and time. He explains this idea further that the “time travelers” world is much like ours, but is a four-dimensional manifold of events, meaning that time is one dimension of the four and there are differences between various time-like dimensions and various space-like dimensions (493).

Hopefully I have no confused you all too much… So where does this leave Back to the Future?

First, a quick description of Back the Future. Marty McFly (Michael J. Fox) is a normal 1980s teenager (what does that mean you ask? Faded jeans, skateboards, and ugly colored vests), who is sent back to 1955 by the crazy Dr. Emmett Brown (Christopher Lloyd) in a plutonium fueled DeLorean. Not only is he sent back thirty years, but when he is there he has to ensure his parents hit it off so the future Marty as well as his brother and sister can exist in the future. Not to mention while he is there he also creates the future “sound” at the school dance by playing “Jonny B. Goode” by Chuck Berry.

Basically Marty needs to ensure that his actions in the past do not erase the reality of himself in the future. As Lewis describes, “a time traveler, like anyone else, is a streak through the manifold of space-time, a whole composed of stages located at various times and places” (493). As Marty travels back in the past his streak is a zig-zag doubling back on himself, actually so far back on himself that it is before he was born. Lewis explains, “you cannot change a present of future event from what it was originally to what it is after you change it. What you can do it change the present of future from the unactualized way they would have been without some action of yours to the way the actually are” (497). This quote ties in directly with Back to the Future because it explains the desire to want to go back and change something in your past to more readily set up your future. Although Marty does not intentionally go back to the future to change something, he has to make sure his parents do in fact end up together so that his life and his brother and sisters lives can be saved.

Now it is time for some personal reflection… Do you think that time exists in this four dimensional sense? If time travel did/does exist and you could travel back to a point in your past would you? Would it be ethical?? My first response is YES I want to go back but then I realize that all the reasons I would want to return are purely motivated by greed or some other poor emotion. Do you think the past is what makes us who we are today? If we could change that past then would we be risking changing who we are for the worst? What do you think other philosophers would say to potential ability to change our pasts?

If you have not yet seen this movie… I highly suggest it and I am hoping that most, if not all, of you have seen it. This was probably my millionth time watching this film. It comes on TV all the time if I am not mistaken. So watch it!