Planet of the Apes and Philosophy

by Huss, John

  The young apes caricaturing the “flower power” youth in Beneath the Planet of the Apes, sitting on the road and chanting “We want peace and freedom, not war” may have it right, no matter how unrealistic cynics may deem them to be. No true morality can come about between distrustful enemies analyzing each other objectively.

  Equality doesn’t have to do with strangers’ respective capacities. It’s a matter of recognition of the other person’s intrinsic worth, rather than of some evaluation of their objective value from the standpoint of the universe. It is a matter of establishing bonds of trust and learning the ways in which we are alike. When these bonds are established, we are equals, not in the sense of possessing the same color, or height, or wisdom, or whatever, but in the sense that we are fundamentally concerned with other beings sharing our fate (or a similar fate) and our planet. We are nonetheless relational beings, capable of both a broad, universal, and a narrower, individualized concern. Such a concern may encompass various relationships which sometimes demand preferential treatment for members of our own species.

  IV

  Ape Spacetime

  8

  We Came from Your Future

  DAVID L. MORGAN

  The Planet of the Apes films are not time-travel movies, they are just movies in which people (and apes) travel through time. The original 1968 Planet of the Apes film, and its 1970 successor Beneath the Planet of the Apes rely on future-directed time travel of a sort that is entirely permissible within the confines of physics, although the mechanisms suggested in the movies are at times rather vague.

  The mere fact of time travel is simply a necessary plot element that sets up the situations explored in the series. In the first movie, as Taylor is recording his final log entry before hibernation, he explains that he and his crew have been in space for six months, “by our time that is. According to Dr. Hasslein’s theory of time in a vehicle traveling nearly the speed of light, the Earth has aged nearly seven hundred years since we left it.”

  In Beneath the Planet of the Apes, future-directed time travel comes with another explanation—Brent speculates that his ship must have “passed through a Hasslein curve—a bend in time.” Of course no such made-up science is necessary to explain this sort of travel into the future. And no new theories, Hasslein’s or otherwise, are necessary beyond Albert Einstein’s 1905 Special Theory of Relativity.

  Fast Forward

  While Einstein’s special theory of relativity does not exactly permit time travel in the sense of “skipping” from the present time to some future time, it does allow for an effect that accomplishes something similar. According to modern relativity, observers moving relative to one another do not experience time in the same way. If you are moving though space very fast—say at ninety percent of the speed of light—time will pass more slowly for you compared to a stationary observer. This allows the crew of an interstellar spacecraft to take a trip that lasts for ten years as measured by those left behind on their home planet, but only eight years as measured aboard the spacecraft. Or five years. Or one year. Or one month! There is no limit to how short the time experienced by the ship’s crew can be as the ship goes faster and faster—ninety percent, ninety-nine percent, 99.999 percent of the speed of light.

  We can deduce something from Taylor’s description of time aboard his ship from the numbers he cites in his log entry. He claims that six months of time have gone by aboard the ship while the earth has aged nearly seven hundred years. Unless Dr. Hasslein has significantly modified Einstein’s theory of relativity, we can conclude that, based on the implied time dilation factor of around 1,400, Taylor’s ship is traveling at around 99.99997 percent of the speed of light.

  This sort of time-travel is a well-established fact of nature. Unstable particles created by cosmic rays at the top of Earth’s atmosphere live longer when they are hurtling towards the ground than when they are sitting relatively still in the lab. Short-lived particles produced in high-energy particle accelerators like the Large Hadron Collider experience this relativistic time dilation in precise agreement with the predictions of Einstein’s theory.

  Gravity can have a similar effect on time. Time flows more slowly for observers in a strong gravitational field than in a weak one. This means that a clock at the top of a tall building ticks a little bit more slowly than one on the ground floor. Of course the difference is measured in fractions of a nanosecond, but the difference is real, and measurable. In fact, the network of GPS satellites, which allow you to determine your location on Earth’s surface to within a few meters based on timing signals received from multiple orbiting satellites, has to take these relativistic time differences into account. If the system didn’t compensate for the fact that time flows at a different rate up in orbit where the satellites are located relative to our GPS receivers on the ground, the timing signals would gradually drift out of sync, and this would cause your location to be determined incorrectly.

  This means that another way to “time travel” into the future is to hang out someplace where the gravitational field is very strong, say just outside the event horizon of a black hole. Time will flow more slowly there for you than for someone located where the force of gravity is much weaker, such as the surface of a planet. If you spend a few years orbiting close to the black hole and then return to your home planet, you might find that centuries have elapsed there. Without violating any laws of physics, you would have effectively travelled into your planet’s future.

  A Backward Disturbance in Time

  The idea that time “flows” at different rates for different moving observers seems strange to us, but it turns out that the sort of limited time travel into the future permitted by Einstein leads to no logical inconsistencies or paradoxes. Time travel into the past is another matter.

  The first entry in the series that deals with time travel into the past is the third movie, Escape from the Planet of the Apes. The film opens with Cornelius, Zira, and Dr. Milo emerging from a spaceship that has splashed down off the California coast in 1973. We eventually learn that the three apes escaped to our time by repairing Taylor’s ship from the first film, and that shortly after leaving Earth they witnessed its destruction via the doomsday bomb explosion that closes the second film. The exact physical mechanism for their time travel from the future back to 1973 is not made particularly clear. Dr. Milo simply refers to a “backward disturbance in time” caused by the shockwave of the exploding Earth.

  Is such a thing possible? There’s no clear consensus among physicists over whether or not the laws governing our universe might permit time travel into the past. But there are enough reasons for hope not to discount the possibility out of hand. The first reason is that the fundamental laws of physics themselves are almost entirely agnostic about the difference between the past and future. The only place the difference between past and future is apparent is on the macroscopic scale—when discussing the flow of heat, or the expansion of the universe, or the functioning of our brains.

  All of the laws of physics that govern the individual interactions between individual objects at the microscopic scale are symmetric with respect to the reversal of time. So it seems as if that “arrow of time” that defines the flow of our experience from past to future is more like an emergent property of our universe than a fundamental one. If this is true, then traveling into the past might not break any fundamental laws of physics.

  But how would we actually do it? How could we build a “time machine”? It turns out that Einstein’s general theory of relativity, the same one which predicts the effect of gravity on the flow of time, allows certain solutions that appear to permit trajectories through spacetime that start in the present and wind up in the past. On paper, anyway. The various time-traveling solutions of general relativity involve exotic objects like “wormholes,” “ring singularities,” and “cosmic strings”—entities which may not actually exist outside of Einstein’s equations as part of the real world. But the very fact that the laws of phys
ics do not seem to expressly forbid time travel into the past, means that it’s worthwhile examining the philosophical implications of the idea.

  Paradox of Escape

  Whatever as-yet undiscovered physics enabled them to travel back to 1973, Escape from the Planet of the Apes opens with the three apes (four if you count Cornelius and Zira’s unborn child) present in the Earth’s “present”—which for them is the past. Their subsequent interaction with modern-day humans gives rise to an apparent paradox. If the humans of the twentieth century learn the fate of their civilization, might they take action to prevent it? This is exactly what Dr. Hasslein has in mind as he tries to exterminate the apes, considering them a threat to humanity’s very existence. But if this attempt to change the Earth’s fate were to succeed, how would we explain the presence of intelligent apes from a future that will now never come?

  The situation which arises in Escape from the Planet of the Apes is an example of what is often referred to as the “Grandfather Paradox.” Imagine you travel into the past to a time before your mother was born, and you track down your grandfather and, for whatever reason, you kill him. With your grandfather dead, your mother will never be born. If your mother is never born, then the question arises—where did you come from?

  Many sci-fi story plots run afoul of the grandfather paradox by choosing to ignore it. Take the plot of the 1984 movie The Terminator. Robots from the future, having nearly won the war against humans, decide to take a radical step to eliminate the remaining human resistance forces. They send a cyborg into the past to murder Sarah Connor, the mother of John Connor, leader of the human resistance. Had the Terminator, played by Arnold Schwarzenegger, succeeded in killing Sarah Connor, we would have been faced with a variation on the Grandfather Paradox—namely, if John Connor never exists, who exactly were the robots of the future trying to kill? Why would the machines of the future send a Terminator back in time to kill the mother of a person who, for them, never existed?

  The scenario that arises in Escape from the Planet of the Apes—where Professor Hasslein’s awareness of Earth’s ape-dominated future seems to enable him to avert it—sets up something like a “Grandfather Paradox” for the franchise as a whole. Should he succeed in averting the rise of the apes, the entire society which gave rise to Cornelius and Zira would never come to pass.

  Of course, that’s not how the story unfolds. Hasslein does succeed in killing Cornelius and Zira, but their son Milo survives, switched as an infant with a circus chimp and raised to adulthood by Señor Armando. Not only does Milo (re-christened “Caesar” by Armando between the third and fourth films) survive, but he goes on to become a leader of the ape rebellion in Conquest of the Planet of the Apes. Not only has Hasslein failed to change the future, it seems he may have been instrumental in setting events in motion that would lead to the rise of apes and the fall of humankind. This suggests a different sort of potential relationship between the actions of past-travelers and their impact on the future from which they departed.

  Escaping Paradox

  The simplest way around the Grandfather Paradox is to deny that it’s possible to change the past. This is not an unreasonable thing to do, given our common-sense understanding of past events. Past events have already happened, so they are “true” for all time. Thus, they cannot be changed. To do so would simply be a logical contradiction. I cannot travel back to 1930 and kill my grandfather, because it’s an eternally true fact about the world that my grandfather did not die in 1930. If I travel into the past, I can only do those things that were done in the past by a time traveler. (Me!) So I cannot travel back to 1930 to kill my grandfather, but I could travel back to 1963 and assassinate John F. Kennedy. But—and this is important—only if it has always been true all along that the “second gunman” conspiracies about the JFK assassination were true, and that second gunman was myself, a time traveler from the future!

  This version of time travel, where time travelers cannot change the past, but only bring about past events as they originally happened, relies on the concept of “closed causal loops.” The idea is that time travel can proceed only via closed loops where past events can be caused by a time traveler, but are never changed by a time traveler. This concept can lead to compelling and paradox-free time travel stories when handled carefully. (My personal favorite is the 1995 movie 12 Monkeys, directed by Terry Gilliam and starring Bruce Willis.)

  At first glance anyway, the third and fourth Apes movies seem to obey the rules for past time travelers as dictated by this “closed causal loop” concept of time travel. Not only do the apes who travel back to the twentieth century not change their past, they take part in those very activities that brought about the future from which they departed.

  Another Model of Time Travel

  What are we to make of time travel stories in which the time traveler changes the past, thereby altering the future that they knew? Are they simply wrong? Is there any room in either physics or philosophy for the notion that we can change the past? There does seem to be room for another way of thinking about time travel into the past.

  An alternative model of time travel asserts that when a time traveler changes events in the past, he or she simply creates another timeline that exists independently of the one they departed. The future they are familiar with ceases to exist, or at least exists now only in an alternate, parallel reality. Events in this new timeline unfold in a way that places no limits on the actions of the time traveler. You are free to kill your grandfather, or Kennedy, or Hitler, or whomever you wish in the past. The Grandfather Paradox is sidestepped, since the answer to the question “If my grandfather died before my parents were born, where did I come from?” becomes—“You came from the future of an alternate universe.” In this conception of time travel, the traveler is more than just a traveler through time—they are a traveler between realities.

  This approach to time travel is encountered frequently in science-fiction stories. One somewhat silly example comes from the 1985 comedy Back to the Future. When Marty McFly arrives in the past, he accidentally prevents his parents from meeting, setting up a version of the Grandfather Paradox that threatens his existence. When he tries to set the situation straight by arranging for his parents to meet at the school dance, he also changes some of the circumstances of the past, by for example convincing his father George McFly to stand up to the bully Biff. The result of this change to his past is evident when he returns to the future (his present) to find his parents as hipper, thinner, and more successful versions of the ones he left originally. By changing the past, Marty gave rise to an alternate universe with an alternate history.

  A more recent movie that takes this approach to time travel is J.J. Abrams’s 2009 Star Trek reboot. When the troubled Romulan, Nero, pursues an elderly Spock through a black hole and back in time, he sets off a whole sequence of events—from the death of Kirk’s father to the destruction of the planet Vulcan—that change their past. This means that the young crew of the Enterprise will experience an entirely new timeline from the one described by the events of the original series. This frees the story from the implications of the Grandfather Paradox altogether. (It also frees the screenwriter and director from the requirement of appeasing demands of continuity and consistency from fans of the franchise!)

  If we examine the Planet of the Apes movies from this angle, we can interpret the small inconsistencies between the films as evidence that the various installments of the series are taking place in multiple parallel timelines. Consider the inconsistencies that are evident between the third and fourth films in the series. In Escape from the Planet of the Apes, Zira and Cornelius describe the events that lead up to the fall of humankind. After a plague kills off the world’s dogs and cats, humans domesticate apes as pets. “They were quartered in cages, but they lived and moved freely in human homes. They became responsive to human speech. And, in the course of less than two centuries, they progressed from performing mere tricks to performing services.” And th
en some three centuries later, according to Zira, the apes began to recognize their enslavement and to quietly rebel. The stage was set for a full-scale revolution when a chimpanzee named Aldo was the first ape to speak. He said “No.”

  Contrast this story with the plot that unfolds in the next movie, Conquest of the Planet of the Apes. Only twenty years elapse from the birth of Caesar until the time when apes are being used in a service role by humans. And it’s Caesar himself who instigates what seem to be the first battles of the ape revolution. Speaking much more than a simple “No,” he delivers an impassioned speech about the coming ape domination.

  What happened to Aldo and the slow, five-hundred-year process of ape advancement and growing discontent? Could it be that by traveling into their past and giving birth to the infant Milo, who would become the revolutionary Caesar, Zira and Cornelius changed their past and set into motion a series events that would accelerate the rise of the apes by centuries? As viewers, we could simply chalk up the inconsistencies as sloppy attention to continuity on the part of the screenwriters. But we might instead use the discrepancies as a case-study for the multiple-timeline conception of time travel.

  There is some direct support for the multiple-timeline idea from the Apes series itself, through one of the few explicit statements made about the nature of time by any of the characters. In Escape from the Planet of the Apes, Dr. Hasslein explains to a television reporter that