The concept of time travel has always been a prevalent idea used in science fiction. Many science fiction stories and novels have dealt with time travel, from classics such as The Time Machine by H. G. Wells to more modern stories such as Woman on the Edge of Time by Marge Piercy. Most believe that real scientists would scoff at the notion that time travel could be possible. It is widely assumed that only na ve science fiction fans would believe that time travel is actually possible.
However, there is much debate between physicists in the science community today over whether Einstein's theory of relativity allows for the possibility of time travel or not. This purpose of this paper is not to discuss the hard science debate on time travel, however. I am going to assume that there is a way to travel in time which modern science cannot comprehend yet. However, if science does eventually allow for time travel, I believe that the question is whether the paradoxes involved in time travel allow for the possibility of going to the past or future. That is the subject of this paper. First, let us look at an example of the paradoxes involved in time travel.
There is of course the classic paradox that is most widely used when discussing time travel. This is the question of what happens if a time traveler goes back in time and kills his parents The answer is he was therefore never born. But if he was never born, how could he have traveled in time to kill his parents He could not have, so therefore his parents should meet and he should be born. And so on, the paradox spiraling in an endless loop of impossibility. An example similar to the previous one is found in Robert Heinlein's 1941 story "By His Bootstraps." While in the future, the narrator, who is also the main character, receives a notebook from an older version of himself. The notebook contains a dictionary of futuristic vocabulary to help the narrator on hi travels.
As the years pass and the notebook becomes tattered, the narrator recopies it into a new notebook from the present. As an old man the narrator then proceeds to give this notebook to his younger version. But the paradox that is created is where did the notebook originally come from (Ross) Originally someone had to have created it. But no, it seems that the notebook was written by nothing. The original knowledge seems to have been lost in a closed temporal loop (Ross).
How is this possible There seems to be no explanation. One more example of the paradoxes involved in time travel is the man with no past. Let us say that a man is trying to invent a time machine, but is having no success at it. Suddenly, an old man appears out of nowhere and offers the aspiring inventor the secret to time travel. The man then proceeds to become wealthy from gambling on the horse tracks and sporting events. Then as an old man he goes back in time to give the secret of time travel to his younger self.
Where did the original idea come from How are these paradoxes resolved Does the universe simply cease to exist in order to end the paradox Or is it something more simple, such as the time traveler and whatever he causes to become a paradox just wink out of existence, and the world moves on as if they had never been there Or is there another explanation that could be given to resolve such a paradox One idea to deal with the problem of paradoxes is that there are an infinite number of timelines that can be created which are parallel to, but at the same time different from the original time line (Kiekeben). This means that as soon as a time traveler arrived in the past or future, that time line would split off from the original one. As a result of this, a time traveler would not be able to change the history of his time line. For example, let us say a time traveler wanted to go back to Nazi Germany and assassinate Hitler in order to prevent the Holocaust. If he was successful in his assassination attempt, the time traveler would be surprised to learn upon his arrival home that the Holocaust did in fact occur and that nothing had changed. This would be because when the time traveler assassinated Hitler, that time line split off from the time traveler's original time line.
If this theory is accepted, then this could not actually be considered time travel. As soon as the time traveler arrives in the past, he is no longer in his past but is instead in another temporal continuum. Therefore this is traveling to parallel universes, which is not really time travel (Kiekeben). Another theory is that time travelers would merely play out the role they have in history (Kiekeben).
If we take the example of the assassination of Hitler in the previous paragraph, then the time traveler would go back in history and for some reason he would be stopped in his attempt. This theory says that the time traveler was present during this period of time but the natural course of history plays itself out and Hitler continues on with his plan of genocide. The problem with this theory is that the time traveler could simply figure out what he did wrong on his first attempt, travel back to the present, and proceed to go back to the past to try again and again until he succeeds (Kiekeben). Eventually there could be a whole army of time travelers trying to assassinate Hitler. Why could they not succeed A solution to this problem would be that time travel is limited.
Perhaps it is not possible to travel to a time where you already exist. This would make sense and fits in with the theory nicely. In the Hitler example, the time traveler would travel back in time, be stopped in his plot to assassinate Hitler, travel back to the present, and in any future attempts to travel back to that time period would be unable to do so. Of course there is the theory that a time traveler is unable to change the past, but is instead reduced to an observer in the past or future, unable to do anything to alter time. Some advocates of this theory believe that there would be some sort of all-powerful force preventing any changes in the time line (Myers 33). Others think that there would be a conservation of events in time (Woolf).
That is, if a time traveler were to travel to the past in order to prevent a friend from being hit by a car and killed and was successful, then the friend would be killed in a new way, perhaps by being hit by a car the next day. No matter how many times the time traveler saved his friend, fate would just deal him another mortal blow in a new way. An example in literature of conservation in time is the story "Behold the Man" by Michael Moorcock. In it a time traveler visiting Jesus Christ is forced to take over Christ's role and impersonate him (Woolf).
This theory of conservation of time leads to Larry Niven's Law of Time Travel. Larry Niven is a science fiction writer who himself has dealt with the issues of time travel in some of his works. Niven believes that the constant smoothing over of a time traveler's meddling would eventually lead to a universe where no time machine was ever invented, and therefore humans are unable to travel in time. Thus Niven states that, "in any universe where time travel is possible, it will never be invented (Woolf)." Arthur C. Clarke, one of science fictions most prolific writers, once said that if time travel were easy, "our past history would be full of time travelers (Bainbridge 81)." This raised a valid point. If time travel were ever to be invented in the future, it would stand to reason that time travelers would be arriving in the present and in the past with great frequency.
There are a couple of theories to deal with this. One is that perhaps when time travel is invented, some sort of government agency is created to watch over the time continuum and prevent abuses of time travel. This is addressed in the movie "Time Cop" starring Jean-Claude Van Damme. In the movie, a technology has been developed to determine when the time line is being tampered with and "time cops" are dispatched to the past to deal with the problem. This would prevent any person from travelling back to make themselves rich or to change history, and it would explain the fact that none of us have ever actually met a time traveler- no one except specially trained people are allowed to travel in time. Another theory to deal with the fact that time travelers from our future are not arriving all of the time is given by L.
Sprague de Camp, a science fiction writer. De Camp says that perhaps time travel is possible only at very weak points, or perhaps critical junctures, in our history (Bainbridge 81). This could be used to explain Connie's travels to the future in the novel Woman on the Edge of Time by Marge Piercy. Connie is able to travel in spirit to the future because she has a special quality about her that allows Luciente to contact her.
Luciente tells Connie that her actions will help to decide the fate of the future. One possible future is the one Luciente is from, a small, back to nature commune called Mattapoisett. The other possible future is a hellish nightmare version of New York City. In an attempt to prevent the evil future, Connie poisons her doctors because they are running immoral tests on her and other mental patients, tests that would help lead to the nightmare society.
Without her travels to the future, Connie would be ignorant of the role she played in deciding which time line the world would follow (Myers 180). Perhaps Connie's trips into the future are only allowed because it is a weak point in the time continuum, a crucial point in deciding the fate of the world. This would fit into de Camp's theory nicely. One more possibility raised by the question of time travel is the occurrence of closed loops (Myers 34). An example of this would be if a man traveled to the past and impregnated a woman with a male child. That child then has a child, who grows up to be the original man who traveled into the past.
The time loop presented here is obvious. Gilbert Fulmer presents an interesting time loop theory (Myers 34). Fulmer wonders if it is at all possible that a time traveler set off the Big Bang, which created our universe. Fulmer says that perhaps in the distant future a time traveler travels back to the beginning of creation to set off the Big Bang. Thus, the time traveler would be what many religions worship as god. Although this theory is certainly interesting, I find it implausible and unlikely.
Somehow the universe would have to have been created originally in order for the time traveler to exist and come back to set off the Big Bang. It is certainly interesting to consider the possibility, however. I have pointed out many of the paradoxes involved in the theory of time travel. A great multitude of stories and movies has dealt with time travel over the course of science fiction's history.
Some of these have dealt with the paradoxical questions raised, and some have ignored them. What is the truth about the solutions to the paradoxes in time travel Perhaps the solution is as simply that time travel is scientifically impossible. Or perhaps one of the solutions I have mentioned previously in this paper solves the problem of paradoxes. New ideas are constantly being generated, and possibly the answer is waiting out there for someone to discover. If time travel is possible, we will not know the answer to the question of paradoxes until the first time traveler makes his first trip into either the past or future.