Who doesn’t expect time travel to occur? It’s all over our science fiction. In any real, fun, and good science fiction, time travel is explored in at least some minor fashion. Need I list all of the fiction of our time that explores the possibility?
Back to the Future
Meet the Robinsons
Men in Black
Star Wars: Rebels
Anyway…you get the idea. Certainly you can think of a list much longer than my own. The point is, time travel is one of those things that we don’t understand…yet. Science will, again, uncover it sometime in the near future and it will be great. All we need is that miracle scientific breakthrough, the magic key that allows us to do what no man has done before. Is there an ethereal Time Vortex, an element of physical space waiting to be traversed? A spacial wormhole that is warped, perhaps by a black hole, that we need to go through? Is it left to magic? Or do we rely on a more intimate connection with a universal force that transcends the body? Or, more obscurely, do we have to find a way to traverse the quantum realm, a degree of physical existence that is so unpredictable we might be able to navigate from one time period to another?
We could, of course, debate all of these minute elements of physical science, but at the end of every single line of debate we will necessarily end up at a question of metaphysics. What, even, is time? Is it an element of reality controlled by a stone? Sorry, that was my last rhetorical question poking fun at a movie…maybe…
But, seriously, is time an underlying force of physical reality? Is it another dimension of space, meaning that it can be traversed with the right vehicle?
For the present article, I have to admit, I will be relying heavily on the philosophical backbone of Edward Feser’s own blog about time. While I have not read his book Aristotle’s Revenge (but I probably should), I am not sure whether Feser directly addresses the matter of time travel. He does have, thought, in that previously linked blog post, a picture mentioning time travel…
Either way, when wondering about time and time travel, one has to conceptualize what the actual nature of time is, and what the consequences of that conceptualization would be.
What exists? You, at the time of reading this, but I may or may not. I might have suffered a tragedy and perished, but if you’re reading this then you certainly exist. But if I have already died, then I no longer exist. My body might exist in some decaying fashion, but that would be all. My person would not exist (in the physical world). When I have drawn a triangle in the sand, it exists. When the ocean washes away the triangle, it no longer exists. I am, of course, speaking of existence in the most strictest of terms. Either something exists or it does not.
If something, like that triangle, used to exist but no longer do, do they exist somewhere else? Most readily I answer: no. Memories of things are not the things themselves, and if they no longer exist in the physical world then they no longer exist. They don’t come back. It’s the terrible notion of death that plagues us all. They don’t keep existing on some back burner somewhere, hiding from our point of view until we want to ‘travel back in time’ and see them again. That beautiful (or terrible) first kiss only happens once. Peanut butter and jelly, mixed together, do not come apart again and into their original containers.
There is certainly evidence of the past having existed, but the point is that it no longer does. Were it not for human memory, were it not for human reason that can deduce temporally anterior causes, there would be no existence of the past, as far as we were concerned. If the past no longer exists, then how can we travel to it?
Similarly we can think about the future. The future is that which is yet to exist. In many ways it is so dependent on the individual choices that there are an almost infinite amount of possible ‘futures’ to go towards. The reality, though, is that one ‘future’ will come true out of all of them, and only one. Once that future comes it will exist, but the future does not exist until it does come.
This idea is explored by St. Augustine in his Confessions. The future is not a year from now, the past a year back, and the present a current year. The whole year does not currently exist. The future is not a day from now, the past a day back, and the whole present day that currently exists. The future is not a minute from now, the past a minute ago, and the present the whole current minute. The future is not a second from now, the past a second ago, and the present the current second. The present is but a fleeting moment, and yet the present is all that exists.
Feser, in his above article, argues that Aristotelians should be presentists, believing that the present is all that exists. The past is no longer accessible and the future isn’t accessible either. All a person has dominion over is the present. Why is that?
Here we answer the question of what time is: itself is nothing. Time is but a measurement of change. Remember what Aristotelian change is? We look at the reduction of potency to act. That change is the movement of future to present. Once that act suffers another change, that act moves into the past and it no longer exists. That is all time is.
So what would be necessary to traverse time? Is it a question of finding the right physical channel? Nope.
This is an impossible modern possibility: we will never be able to physically travel to the past and we will never be able to “travel” into the distant future.
To be able to travel in time means needing to transcend the reduction of potency to act, but can we ever do that? The sheer act of traveling in time, the idea at least, is itself a reduction of potency to act, not a transcendence of the movement of change itself.
At best, even if we could manage some level of transcending material change, existing sans-materiality, the type of time travel would never be something of a material journey – it would have to be an immaterial journey. As the past is only known through memory, we would essentially have to travel within someone’s memory. Once we were there, all we would be able to see is the immaterial. Here, essentially, think like Assassin’s Creed – going into “genetic memory” (a ludicrous idea, by the way) and reliving past experiences. But that isn’t really time travel, is it?
Of course, we are always traveling towards the future, and as we pass moment to moment one might argue we are time traveling into the future. One could even conceive of traveling to the future by means of some deep sleep that somehow preserves our bodies. But usually when someone talks about traveling to the future, an inherent sequiter is ‘and also traveling back to the past.’ But, as already argued, there wouldn’t be a return journey. So would it really count as “traveling” to the future?
In the end, the most resolute conclusion we can come to is that time travel is not, and never will be, possible. No future discovery of science will unveil the means for us to transcend causality and change, for if a subject of study transcended change, science would never be able to study it. Every moment preoccupied about the past or future is another moment of the present that is wasted.