Time travel is something that has always interested me immensely.  It seems like much of my free time ends up being allocated to reading about time travel. Although I very clearly lack the technical skills to understand it very well from a physics perspective, I still try to read the sort of science books that are intended for people of my deficiencies in addition to science fiction. By these I mean books like a Brief History of Time, which are clearly intended to elucidate these concepts for a numbskull like myself.

While I would undoubtedly find it impossible to debate or even understand many of the actual mechanics of time travel, I can still approach it from a literary and philosophical perspective to try and explicate some of its apparent inconsistencies and logical issues.

One thing that has always fascinated me is the time paradox.  I’m sure we are all familiar with the concept; everyone is always asking, “What would happen if we killed our own grandfather?” For many it has become clear that time paradoxes cannot exist because if they do it would destroy causality, which to most of us would be unthinkable. It would create an endless and illogical time loop. Authors and others who like to hypothesize about time travel often get around this by saying you must create your grandfather or even be your grandfather. Reality is contingent on this act; therefore it must necessarily happen.

There is a problem with this, however, because in order to have made your grandfather, logically a grandfather must also have existed in the first place without your intervention. Otherwise the cycle could have no beginning. So then we must say that a grandfather did initially exist but it was destroyed when you traveled back in time. There was one reality, but it was permanently removed and a new timeline was started.

In other words the present hasn’t changed, but the events that lead to the present have. We are all the same people, but what made us the same people has changed. But now there is a new problem: we have violated the philosophical notion of non-contradiction. An object cannot both have existed and then have never existed. Reality cannot be contingent on something that never existed, but to suggest anything else is equally absurd.  So if time travel is possible in the sense that literature describes it to be, it either violates causality or non-contradiction.

I will admit that there are other ways to avoid this scenario, you may tweak the perceptions of the people involved or historical perceptions to allow for it to happen that the grandfather was always created by you, it was just never known. I feel that what is of most import is ruling out what cannot happen to avoid creating a situation that will render the reader, or in this case the thinker, a gibbering mass of metaphysical angst.

Something else that interests me hugely was something Stephen Hawking once said. He noted that the absence of tourists from the future constitutes evidence that time travel must be impossible.  This got me thinking about the other explanations for why we aren’t being hounded by tourists for authentic 21st century Macbooks or other souvenirs.

There are actually quite a few other potential reasons why this doesn’t happen. One: time travelers have wisely decided to disguise themselves in order to avoid messing with causality.  Two: time travel does exist, but nobody does it to avoid messing with causality. Three: time travelers have already interfered with causality, but we would have no way to know how and why (maybe Jesus was from a future in which he never existed). Four: time travel does exist, but our civilization destroys itself before developing the technical ability to utilize it.

These were the best of the ones I could come up with; however, I do not expect them to be the end of the list.  Number four is probably the one that is most in the vogue of our current time, but it is also interesting because it introduced the idea to me of extrapolating the future based on that which hasn’t happened.

But at this point you may be asking yourself “What is the point of all this positing? We don’t know time travel even exists, and you clearly don’t have much knowledge about it.”  Well to answer this I say that we think about these things because they amuse us and because they are a curiosity. Is there any real practical value to consider things like this that are a small shaky step from metaphysics?  Probably not. Without understanding the real driving forces behind time this level of extrapolation is basically irrelevant.

But it is interesting, is it not?  And ultimately considering a curiosity or just following a line of thought because it amuses us is really all there is to life.

Everything else is just a more complicated form of survival.  Sometimes people ask me “why do you continue to live?”  usually after I explain my philosophical and theological perspectives.  The answer to this is quite simple: life can be interesting. As soon as it ceases to be so you will find me quietly exiting the arena of life but until then I will pursue whatever inane tangent my mind takes me on.