Eternalism vs. Presentism: How Soon is Now?

“Yes, and imagine a world where there were no hypothetical situations” ― Jasper Fforde, First Among Sequels

I have a bone to pick with the science fiction genre.  Well, two bones really.  The first is that they cancelled Farscape and Firefly.  The second is that the entire oeuvre makes us believe anything is possible, and we are sadly disappointed when this turns out to be existentially untrue.  For generations we have been steeped in the notion that time travel is possible.  It’s a trope that has spawned many a popular book or movie and has led the rest of us to presume that it’s just a matter of applying enough brain power to the problem, and eventually we’ll be vacationing on dinosaur safaris or having Christmas dinner with Henry II and Eleanor of Aquitaine.

One of my favorite pastimes is envisioning worst-case scenarios, which makes me the perfect candidate for a position in threat analysis, but a rather insufferable husband. I have been nigh well obsessed with time travel since as a 10 year old lad I read William Sleator’s The Green Futures of Tycho.  I’ve followed the strange phenomena literature for a few decades looking for evidence, or at least tantalizing clues that the miracle of time travel might one day be a reality, and been sadly disappointed (nobody showed up to Stephen Hawking’s party, which is just rude).  Since we’re delving into my twisted psyche, I’m also a big fan of Boethius’ Consolations of Philosophy, a treatise on “how happiness is still attainable amidst fickle fortune” that he wrote while awaiting trial and eventual execution.  Thus, when my expectations exceed reality, I turn to philosophy.  This really doesn’t solve anything, as most philosophers die resoundingly dissatisfied and in abject poverty.  That’s why I keep my day job and have a fondness for scotch.  Since physicists largely can’t agree on what time actually is, the ultimate question about whether time travel is possible comes down to the ontological debate about eternalism vs. presentism, the two leading philosophical perspectives on time.

The basic conundrum is this: (1) If the presentists are right (save a few philosophical contortions out of desperation and wishful thinking), time travel is impossible, or (2) If the eternalists are right, time travel could be possible.  I’m a glass is half-empty kind of dude, so my suspicion is that the presentists have a good handle on the universe, since anything else suggests our reality is a lot more interesting than we give it credit for.

Let’s start with eternalism.  General Relativity, according to many philosophers, implies that both the past and future exist in a real sense.  If time is indeed a dimension, like location in space, then the same way that two locations exist independently, so too might two times exist independently and simultaneously.  Good news for our would-be time travelers.

Alternatively, presentism suggests that the future and past only exist in relation to the present and have no existence of their own.  In this case, time travel would be fundamentally impossible because there would be nothing to travel to.  This would imply that we are stuck in the now.  Presentism is usually thought to be irreconcilable with General Relativity, because, well, it’s all relative.  One person standing still and another moving close to the speed of light would disagree on what constitutes “the present”, and both would be correct, since presentism would require the same physical object moving in time to be both real and unreal.  The main problem is those darn quantum physicists busy getting uppity about General Relativity.  Physicists can ruin any party.

So, what if we are stuck in the “here-now”, as the presentists suggest?  This is a problem for anomalists as there would be no fundamental mechanism for such things as clairvoyance, precognition, prophecy, and a bevy of other Fortean phenomena involving time to operate upon.  Ontological questions can be a real downer sometimes.

I am of course, grossly oversimplifying the whole matter, but the essential point is that ontological perspective can be quite determinative of what goes on in our tiny little brains.  Learning to examine our ontological assumptions compels skeptic and believer alike to step into the realm of infinite possibilities (including one where maybe time travel is possible, if I’m lucky).  Obviously, this is not a simple thing to do.  Our patterns of thinking become engrained and comfortable, but we can take solace in the likelihood that Samuel Beckett was correct when he said, “One is what one is, partly at least”.  And if there are any time travelling tourists out there reading this, I’m having a party at my house last Thursday.  Bring your own beer.