The Time Travel Fallacy, part 2

This is the second part of a multi-part series on time travel, posted weekly on Tuesdays. For part 1, click here.

A sequel? Well, all right...

Now that we've discussed the problem with time travel's effects on reality and events, I'd like to move on to the issue of why no one has ever been outed as a time traveler. (I think the closest we've come is Nicolas Cage, the immortal / time-traveler).  Are time travelers that stealthy? What's the deal? Without further ado, let's dive in.

Issue 2: If time travel were possible, we would have already encountered travelers at some point in history.

This one is pretty easy to wrap your head around, even if its implications are pretty far-reaching. If, at some future time, humans gain the ability to time travel, why have there been no confirmed (or as far as I know, officially reported) instances of encounters with time travelers? One could easily imagine a situation where someone heads back in time and is unable to hide their identity as a future-person, thus tipping off those of us in the past. For instance, if future time travel becomes a new recreational activity (like the time vacations that are so common in the future in Family Guy), it would seem inevitable that someone would slip up and let the cat out of the bag. Because this has never happened, it leads to one of three possible results:

     (1) time travelers have been unfailingly diligent in covering their tracks,
     (2) time travelers have rarely to never visited a time in which humans exist, or
     (3) time travel simply is not possible.

I would argue that possibility (3) is the most likely on this list. The chances that no one will ever slip up while time traveling is all but impossible, even if authorities are somehow able to restrict its use to "official, non-commercial use only," like the military tries to do with a lot of groundbreaking new technologies today. Only an outright ban on all time travel (before it even begins to be used) will prevent a foul up in traveling to the past. Possibility (2) is also very unlikely, because the thought of traveling to times in which past, historically recorded events have occurred is essentially the main draw to the ability to time travel. There is very limited utility in only traveling to times in which trilobites roamed free and humans were millions of years in the future.

This list of possibilities ignores the possibility that is always looming in the margins of such things: that the answer is "we can't comprehend it with current understandings." I'm willing to accept that as a possibility, it just doesn't make for a very interesting discussion. Perhaps there is some future technology that renders it impossible to unmask a time traveler, or perhaps there is some aspect of the time travel process that perfectly disguises the fact of travel. But while that is possible, remember that the simplest explanation is usually the right one. And in our case, the simplest explanation is that, given the concerns above, time travel is not possible.

I recognize that an argument could be made that relates the fact that no one has verifiably encountered aliens. The gist would be that, the above scenario, when applied to alien encounters would essentially mean that there are no intelligent life forms on other planets. That is a logic leap I am less willing to make for a few reasons. First, there is a difference between the two subjects because aliens would travel (presumably) in their contemporary time, so there's nothing that says we would have to have already encountered them if they are out there. Think: if they are progressing technologically at the same rate as humans (from the same starting point), we would not have encountered them at this point because we have not been able to travel intergalactically ourselves.

If he can become a flaming skeleton, time travel's a cinch.

The other key difference is the application of Occam's Razor. In the time travel situation, it is indeed simpler to say we have not encountered time travelers because time travel is not possible. But with regard to aliens, the unimaginable vastness of space tilts the scale, leading me to believe that the simplest explanation (which is usually the right one) is that we haven't encountered visitors because (1) we haven't expanded our own universal footprint enough to find them ourselves and (2) there is simply a lot of empty space out there.


To summarize: if time travel is possible, where are the travelers? Is Nicolas Cage the only one who has been allowed access to time travel? Or is he the only one who (may have) slipped up? I suppose we just don't know (yet).