by Sam Morris, Staff Writer

For as long as I can remember, I’ve loved thinking and talking about time travel. Logic puzzles were one of my favorite things to spend time on as I grew up during the 1980s. Time travel is very much a logic puzzle: If a single event in history changes, what anticipated changes will also occur? My dad is an engineer, so I was familiar with the principle of anticipating variables and eliminating as many as possible. (Yes, I was in the theater the day that Jurassic Park premiered—and, yes, I thought Ian Malcolm’s chaos theory was awesome. But that’s a different story.) Later, in college, because I wasn’t a big enough nerd as an English major, I began to study physics to understand the real science behind a not-real pursuit. 

More than anything else, though, Michael J. Fox and Keanu Reeves are directly responsible for my love of time travel. Marty McFly and Ted “Theodore” Logan are the consummate accidental time travelers. Their journeys fueled my interest, although it was much later in life before I figured out why. Sure, both actors are two of the most charismatic people in Hollywood, but what it comes down to are the ways in which they both portray characters who discover during their time traveling adventures what it means to do the right thing for the right reason. Time travel, in other words, is the study of ethics. You can keep your trolley car—give me a DeLorean or a phone booth. Or, more accurately, as I will do here every month, give me a time travel film and I’ll break down the science and ethical philosophy behind it.

History cannot be changed. Metaphysical philosopher William Grey claims, “The whole notion of time travel rests on an unfortunate spatial analogy which leads to a denial that there is any significant asymmetry between past and future. Time however branches forward but not back. The past is the realm of determinate fact; the future is the realm of unrealized possibility. The past is fixed, the future is fluid” (68). In his discussion on the matter, physicist and mathematician Paul J. Nahin argues that many religious philosophers, including Thomas Aquinas, argued that even God is incapable of changing History: “Aquinas took the . . . position that part of God’s law is that there be no contradictions in the world and that certainly God would be bound by his own law” (264). There is no messing with history; it cannot change nor can it be changed.

But how is that true? History changes all the time! Literally! History has changed from the time you began reading this article to right now. And now it has just changed again! History as we know is added to at the end of each moment by the moment that we just experienced. Not only does History change, we provide agency to History when we talk about how it determines the various courses of our lives; we can be victims or victors, we believe, depending on how History produces a given set of circumstances. Picture George McFly at the beginning of Back to the Future talking about how a single event determined his entire future.

That brings us to the big question: What if we had the ability to directly interact with History? What if, instead of glimpsing History out of the corner of our collective eye, we could interact with it? Would we be able to affect it just as we claim that it affects us? These are some of the questions taken up in many classic science fiction narratives when time travel is involved. In Stephen King’s 2011 novel 11/22/63, History does not want to be affected by the time traveler and fights back. Theorist and critic Slavoj Žižek wrote that “we can say that in a sense everything has already happened; all that is actually going on is a pure change of form through which we take note of the fact that what we arrived at has always already been” (221). But what if that wasn’t true? In the 1980s, films such as The Terminator (1984), Back to the Future (1985), and Bill & Ted’s Excellent Adventure (1989) showed audiences that the past can (and should) be changed for the sake of some societal benefit. 

That brings us to the other big question: Given the ability to change History, should History be changed? Does the time traveler have an ethical obligation to either History or humanity? If there is such an ethical obligation, we must then determine what that obligation is and whether or not it is met in time travel narratives. In the The Terminator and Bill & Ted’s Excellent Adventure, a narrative device is created by the filmmakers to let audiences know immediately that if the time travel the film features does not occur, then humanity will end. If there is a suitable and ethical rationale for time travel, surely the extinction of humanity must be it. Alternatively, in Back to the Future, Marty McFly travels to the past by accident, and he ends up changing his present in a personally profitable manner (though perhaps at the expense of others). An examination of the ramifications of these narratives, fictional and (currently) scientifically implausible as they are, allow for an exploration of how we conceptualize, rationalize, and interact with History.

Ah, ethics. Is time travel problematic because it violates the laws of physics via reverse causation, or is time travel an ethical problem? When the machines send the T-800 back to 1984, are they violating the laws of physics or are they “cheating” by breaking the audience’s code of ethics? Even if the audience believes that the machines are cheating, it would be difficult for that same audience to see the actions of John Connor and Kyle Reese as unethical since they are working to police the unethical actions of the machines. Besides, Reese wants to become integrated into 1984 because of love, which is, at least in Hollywood, a good reason to do just about anything. The fact that Reese dies at the end of the film happily precludes the possibility of any extra interference with the past. 

Since time travel is beyond the scope of scientists today, there is no way to definitively determine which consequences of time travel are real and which ones are imagined. The only answer that one can provide is one that is bound by the particular point in time in which the question is answered. In the 1980s, time travel was generally permitted under certain ethical parameters: 1) the future of humanity depends on it, or 2) the person who benefits from changing the past deserves it. In the 21st century, the conversation has shifted; gone is the narrative of a single timeline, replaced by a more popular narrative that is supported by quantum theory. In quantum theory, when Marty McFly steps out of the time machine in the new 1985, he actually steps into a parallel universe. Loser Marty still exists in the “original” universe of 1985, but Time Traveler Marty has accessed a “new” universe that is identical in every way to the original one except for the local changes that occurred as the result of his sojourn into 1955. 

Indeed, since the 1980s, Hollywood has come to embrace the quantum theory of time travel; after the critical and commercial failures of Terminator 3: Rise of the Machines and Terminator Salvation, the most recent entry in the Terminator franchise, Terminator Genisys, deconstructed the timeline with which audiences were familiar by changing the events that occurred in The Terminator—meaning that events in subsequent films never happened. In actuality, however, the writers of the film asserted that the events of The Terminator did happen—but in a parallel universe.

While films that operate in this more relativistic theory of time travel, such as Terminator Genisys and Looper, operate with an attitude toward time travel that borders on flippancy due to the complexity and inherent exhaustion mentioned above, audiences today remain interested in the paradoxes and ethical dilemmas of earlier time travel films. Were we simply more interested in films with “heart” in the 1980s than we are now? For an audience in the 21st century that has to struggle with quantum physics to comprehend the plot of Interstellar, answers to the ethical dilemmas that time travel narratives pose are not as simple or as important as they once were in films such as The Terminator, Back to the Future, and Bill & Ted’s Excellent Adventure. 

Science fiction provides a unique opportunity for authors to explore humanity—both the nature of humanity itself and issues related to it—in a speculative space that is still not out of the realm of possibility. In time travel narratives particularly, authors often challenge the notion that history is a fixed object. In doing so, their goal is not to imagine what a world would look like without Hitler and the Third Reich; rather, their goal is to examine how a traveler’s conception of ethics and humanity are challenged by this new possibility.

Works Cited

• Grey, William. “Troubles with Time Travel.” Philosophy, vol. 74, no. 287, 1999, pp. 55-70.

• Nahin, Paul J. Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction. 2nd ed., AIP, 1999.

• Žižek, Slavoj. The Sublime Object of Ideology. Verso, 1989.