The Philosophy Club will host two Filmosophies this year. This is our discussion of film and philosophy, showing some philosophical issues depicted in popular films. The first one we will present, on a day still to be determined, but soon, is on Star Trek, and conceptions of time.
A famous argument about the possibility of time travel rests on the so called "Grandfather's Paradox." It is argued that time travel is impossible. Suppose someone [a] could go back in time, to a time before their father was born. Suppose that either by accident or by choice [though it would be strange choice], the person going back in time kills their own grandfather. Then it is impossible for a to have ever been born, and thus that a went back in time to kill his grandfather. But if time travel is possible, it seems odd to think some power keeps him from killing his own grandfather. The possibility of time travel thus creates the possibility of inconsistent self-reference, like the liars paradox ["I always lie. Even that is a lie."] But that is impossible, so time travel is impossible.
Many works of science fiction present time travel as a real possibility, however. Some movies which do this include Back to the Future, the original Star Trek series, The Terminator, and the new Star Trek movie. All three attempt to deal with the grandfather's paradox in different ways.
In Back to the Future, McFly goes back into time, and alters it. He meets his mother, instead of his father. His mother develops a crush on him, instead of developing a crush on his father. As the movie continues, the effects of this change continue to develop. While looking at a picture, McFly's brother and sister start to disappear. Because the situation is impossible, one horn of the dilemma is physically eliminated. But oddly, this happens slowly, so that the future is half there, half not, like in some quantum state. This, if we stop and think about it, is very odd. If McFly's actions eliminate the future he knew, how could it still be half there? Why would it eliminate the lower half of someone? And how could that affect a picture taken in the future? Some sort of reverse causation would have to be in effect. The absence of something [McFly's brother] would cause an independnent thing [the picture of McFly] to cease to exist. By 'independent, I mean under normal circumstances, the picture can continue to exist even if the object of the picture does not, and vise versa.
The old Star Trek series used time travel serveral times, and each time the Grandfather paradox plays a central role. In one episode, "The City on the Edge of Forever," involves a McCoy who accidentally injects himself with a serum that drives him insane, and jumps into a time travel machine, where he changes history, making the Enterprise immediately disappear. McCoy apparently saves the life of someone who keeps The USA out of WWII for too long, making Nazi Germany win the war, and history to change. [Interestingly enough, though the Enterprise disappears, the members of Kirk's landing party do not.] Here, the grandfather paradox still works itself out by eliminating one future, and replacing it with another, but inconsistently does not apply itself to itself, eliminating the self reference. Kirk is still there, even though he cannot be if the Enterprise is not in orbit around the planet. The same is true for McCoy. But if McCoy does not jump into the time machine, then how did the past unfold? Someone changed history. Where did that someone come from, if there is no Enterprise?
In the Terminator, the machines attempt to use the Grandfather paradox to eliminate the person who threatens their victory. But it is not clear what happens to the reality that the cyborg and John Conner's world if the cyborg wins. Be that as it may, the Terminator suggests a strongly deterministic view, where the changes that someone appears to make actually are the things which happened to lead to the future that 'really' happens. Here time travel is possible, and does not lead to the paradox. Instead, Like Oedipus Rex, attempting to avoid our fate leads us right to it. I suppose that if we were to go back and kill our grandfather, we may only discover that he was not our grandfather, but that our grandmother had an affair, so that we are still born, and can still go back in time. Time becomes something that has an endless loop within, as each time the future reaches the point where someone goes back in time, they go back, and do the exact same things.
More next week.