On the history of time travel.

On the history of time travel.

From the beginning, artists understood that time travel either denies humans free will or else creates absurd paradoxes.

This conundrum arises whenever an object or information is allowed to travel backward through time.  Traveling forward is perfectly logical – after all, it’s little different from a big sleep, or being shunted into an isolation cell.  The world moves on but you do not… except for the steady depredations of age and the neurological damage that solitary confinement inevitably causes.

A lurch forward is no big deal.

But backward?

oedipusConsider one of the earlier time travel stories, the myth of Oedipus.  King Laius receives a prophecy foretelling doom.  He strives to create a paradox – using information from the future to prevent that future, in this case by offing his son – but fails.  This story falls into the “time travel denies humans free will” category.  Try as they might, the characters cannot help but create their tragic future.

James Gleick puts this succinctly in his recent New York Review essay discussing Denis Villeneuve’s Arrival and Ted Chiang’s “Story of Your Life.”  Gleick posits the existence of a “Book of Ages,” a tome describing every moment of the past, present, and future.  Could a reader flip to a page describing the current moment and choose to evade the dictates of the book?  In Gleick’s words,

the_red_book_-_liber_novusCan you do that?  Logically, no.  If you accept the premise, the story is unchanging.  Knowledge of the future trumps free will.

(I’m typing this essay on January 18th, and can’t help but note how crappy it is that the final verb in that sentence looks wrong with a lowercase “t.”  Sorry, ‘merica.  I hope you get better soon.)

timetravelGleick is the author of Time Travel: A History, in which he presents a broad survey of the various tales (primarily literature and film) that feature time travel.  In each tale Gleick discusses, time travel either saps free will (a la Oedipus) or else introduces inexplicable paradox (Marty slowly fading in Back to the Future as his parents’ relationship becomes less likely; scraps of the Terminator being used to invent the Terminator; a time-traveling escapee melting into a haggard cripple as his younger self is tortured in Looper.)

It’s not just artists who have fun worrying over these puzzles; over the years, more and more physicists and philosophers have gotten into the act.  Sadly, their ideas are often less well-reasoned than the filmmakers’.  Time Travel includes a long quotation from philosopher John Hospers (“We’re still in a textbook about analytical philosphy, but you can almost hear the author shouting,” Gleick interjects), in which Hospers argues that you can’t travel back in time to build the pyramids because you already know that they were built by someone else, followed by with the brief summary:

All Giza PyramidsAdmit it: you didn’t help build the pyramids.  That’s a fact, but is it a logical fact?  Not every logician finds these syllogisms self-evident.  Some things cannot be proved or disproved by logic.

Gleick uses this moment to introduce Godel’s Incompleteness Theorem (the idea that, in any formal system, we must include unprovable assumptions), whose author, Kurt Godel, also speculated about time travel (from Gleick: If the attention paid to CTCs [closed timelike curve] is disproportionate to their importance or plausibility, Stephen Hawkins knows why: “Scientists working in this field have to disguise their real interest by using technical terms like ‘closed timelike curves’ that are code for time travel.”  And time travel is sexy.  Even for a pathologically shy, borderline paranoid Austrian logician).

Alternatively, Hospers’ strange pyramid argument could’ve been followed by a discussion of Timecrimes [http://www.imdb.com/title/tt0480669/], the one paradox-less film in which a character travels backward through time but still has free will (at least, as much free will as you or I have).

But James Gleick’s Time Travel: A History doesn’t mention Timecrimes.  Obviously there are so many stories incorporating time travel that it’d be impossible to discuss them all, but leaving out Timecrimes is a tragedy!  This is the best time travel movie (of the past and present.  I can’t figure out how to make any torrent clients download the time travel movies of the future).

timecrimesTimecrimes is great.  It provides the best analysis of free will inside a sci-fi world of time travel.  But it’s not just for sci-fi nerds – the same ideas help us understand strange-seeming human activities like temporally-incongruous prayer (e.g., praying for the safety of a friend after you’ve already seen on TV that several unidentified people died when her apartment building caught fire.  By the time you kneel, she should either be dead or not.  And yet, we pray).

Timecrimes progresses through three distinct movements.  In the first, the protagonist believes himself to be in a world of time travel as paradox: a physicist has convinced him that with any deviation from the known timeline he might cause himself to cease to exist.  And so he mimics as best he can events that he remembers.  A masked man chased him with a knife, and so he chases his past self.

screenshottimecrimesIn the second movement, the protagonist realizes that the physicist was wrong.  There are no paradoxes, but he seems powerless to change anything.  He watched his wife fall to her death at the end of his first jaunt through time, so he is striving to alter the future… but his every effort fails.  Perhaps he has no free will, no real agency.  After all, he already remembers her death.  His memory exists in the form of a specific pattern of neural connections in his brain, and those neurons will not spontaneously rearrange.  His memory is real.  The future seems set.

But then there is a third movement: this is the reason Timecrimes surpasses all other time travel tales.  The protagonist regains a sense of free will within the constraints imposed by physics.

Yes, he saw his wife die.  How can he make his memory wrong?

Similarly, you’ve already learned that the Egyptians built the pyramids.  I’m pretty confident that none of the history books you’ve perused included a smiling picture of you with the caption “… but they couldn’t have done it without her.”  And yet, if you were to travel back to Egypt, would it really be impossible to help in such a way that no history books (which will be written in the future, but which your past self has already seen) ever report your contributions.

Indeed, an analogous puzzle is set before us every time we act.  Our brains are nothing more than gooey messes of molecules, constrained by the same laws of physics as everything else, so we shouldn’t have free will.  And yet: can we still act as though we do?

We must.  It’s either that or sit around waiting to die.

Because the universe sprung senselessly into existence, birthed by chance fluctuations during the long march of eternity… and then we appeared, billions of years later, through the valueless vagaries of evolution… our actions shouldn’t matter.  But: can we pretend they do?

I try.  We have to try.

On wasteful medical spending.

On wasteful medical spending.

Given that our bizarre medical spending practices could doom the U.S., it feels strange to write about this topic as a participant-observer.  So let me state upfront: I tried!  I argued with my medical care providers for several minutes, trying to keep them from wasting money.  I used logic.  I cited evidence.  I lost the argument.  They stuck to their position with the unwavering intransigence of bureaucratic rule-followers.

They were probably right to ignore me.  If a bigwig in a suit writes guidelines saying, “Do it this way,” a nurse or doctor might be fired for doing things differently.

Art by MTS<:U on Flickr.

The background: many people in my hometown recently contracted mumps.  Those who work with young people were instructed to get a “mumps titer” — this means measuring the concentration of mumps antibodies in a person’s blood — and those with low readings would be told to get vaccinated.

Sounds sensible enough.  But the titer is more expensive than the vaccine, and we have the vaccine in abundance, so I went in and asked them to just vaccinate me.  Yes, I was vaccinated already as a child, but it doesn’t hurt to get a booster.

They refused.  It’s a live vaccine, see?  To vaccinate you, they inject the actual virus.  The goal is to produce a “subclinical infection.”  But some adults have an adverse reaction — they get sick.  To minimize risk, our health care provider wanted to vaccinate only those people who seemed to need it.

The problem with this logic is fairly clear — although some people may get sick from the vaccination, the people who get sick are going to be those who were not yet immune.  By screening people with high titers, the total number of patients suffering an adverse reaction won’t go down at all.

The faulty logic would be problematic even if the mumps titer was a good assay.  But it’s not.  It’s fairly well known that it produces many false negative results — people who appear not to be immune to mumps, but are.  According to my health care provider’s policy, many people who are already immune to mumps will be vaccinated again.

This is fine from a health perspective, of course.  A second immunization will not hurt.  These people are very unlikely to get sick from the attenuated virus.  The only problem is that money was wasted on the titer.

Worse, common titer assays have a fairly high false positive rate: that is, people who appear to be immune, but aren’t.  Under my health care provider’s plan, these people won’t be vaccinated.  Now, these are people who might get sick from the vaccine — but they’d get much sicker if exposed to the actual virus.  If they’re not vaccinated, they’ll be left at high risk.


Compared to simply vaccinating everyone, testing everyone by mumps titer costs somewhere around twice as much.  Add in the number of vaccines that have to be given after the tests and the plan is even more expensive — even if everyone in the population already is immune to mumps and you’re only giving booster shots to those with false negatives, that could easily be twenty percent or more.  If you’re dealing with a mixed population where some people aren’t immune, the outlook is worse.  Then you’re also risking that someone with a false positive result, whom you decline to vaccinate, gets sick.  Mumps can make you very sick, especially adults.  It can cause brain inflammation — my father, who contracted mumps as a child, needed a spinal tap to get through it.  A scary procedure.  Much more expensive than the vaccine.

(Well, a spinal tap now is much more expensive than the vaccine now.  For my father to have been vaccinated, someone would have had to build a time machine and launch the shot into the past.  Time travel takes huge amounts of energy & is rather more expensive than a spinal tap.)

Nobody at my health care clinic was convinced.  They were adamant.  No vaccine without phlebotomy!

At least the universe has a sense of humor.  After all that, of course my titer would be a false negative.  Their money wasted, they called me back and had me get the unnecessary shot.  Just like I’d requested from the beginning.

On time travel movies, particularly Timecrimes.

TImecrimesTimecrimes is the best time travel movie I’ve ever seen.

Which seems like pretty high praise.  There are lots of time travel movies out there: this isn’t a category like “best cowboy movie where the shootouts are replaced by drug trips” (Renegade) or “best cowboy movie where the shootouts are replaced by ramen noodles” (Tampopo) or “best cowboy movie that’s actually a t.v. show and set in outer space” (Cowboy Bebop  – although if you want to add the stipulation “and isn’t a cartoon” then my answer would be Firefly).

“Time travel movies” is a category broad enough that it probably takes more thought coming up with the answer than was put into delineating the category, as opposed to all the above.  And there are plenty of reasonable entries: Donnie Darko, Terminator 2, Primer, Back to the Future, Groundhog Day.  But I think Timecrimes is best.

You should watch it, if you haven’t.  If you like time travel movies.  Maybe even if you don’t, or haven’t yet.  Because, who knows, maybe you’ll still appreciate seeing the best.

And you should watch it, if you haven’t, before you read this essay.  Because you might be one of those people who likes to be surprised by things, or likes to experience a plot with your mind untarnished by expectation, and I can’t very well explain what’s so great about it without giving a lot of that away.

Here, look, just to be extra kind, I’ll do some more dithering-style typing.  So that your eyes don’t accidentally flit down and spoil things for you.

After borrowing the movie from the library, I wound up quite worried that it would be terrible.  Because often movie previews are for things that are vaguely similar to what you’re watching, right?  Like, “if you liked this enough to rent / buy / borrow it, maybe you’ll want to see these other things, too.”  And one of the previews was for (I assume I’ll have the names wrong for these, because I am actually writing this essay about four years after last watching Timecrimes – it’s that good!  Sticks with you, man) a movie called like “Bus!” or something, about sorority women who couldn’t step off this bus or else they’d be attacked and killed, and one called “Quill!“, about a deadly porcupine?  Something like that.

So I felt worried.

And then the movie started, and it was terrible.  Like, it felt unwatchably bad.  But I switched the audio from the English dubbing (why would that be the default?) into the original Spanish and it was much better.

Okay, that’s plenty of dithering.  If you’ve read this far and still haven’t watched the film, you deserve to have it ruined for you.

Timecrimes is great because it has this really serious message about information sets, and it conveys it in an interesting way, in the form of a puzzle that the protagonist has to solve.

And there are some objections you might raise, as far as why you might think that the virtues described in the above sentence are insufficient to redeem the film.  At least, K had these objections.  So maybe you would have them to?  I don’t know what kind of movies you like.

• Why did the innocent woman have to die?

This was what upset K most.  But the thing is, someone had to die.  Because the protagonist realized that the time machine was horrible, so there had to be extremely high stakes in order to get him to go into the machine again.  This aspect lends a degree of nobility to his acts – the only reason he would have used the machine again would be to save his wife.

• Why did he mimic all those horrible acts at first?

Right, so, he chased and stabbed his past self after first going back in time.  But only because he thought he had to.  The time machine technician had convinced him that if anything happened differently on this trip through the time line, horrible consequences could occur.  Who knows, maybe incongruity / destruction of the universe type consequences.  So he was worried that he would disrupt things and tried his best to ensure that everything happened exactly the way he remembered it.

It was only on his second trip back through time that he tried to change things.  Because at that point his wife had been killed.  So, in order to save her, he specifically tried to alter the past.

For me, the movie progresses through three phases, all after he finds the time machine.  In the first, he is afraid of changing anything and is trying to act in ways that reproduce his memories of the past.  In the second, he is afraid that he won’t change things and that will mean his wife will die.  And then, in the third phase, after he wakes up in the car, he has realize that he can’t change anything.  He tried to, he failed, everything matched his previous memories perfectly.  And it would make sense, right?  If there were time travel, then everything should line up, because the inside of his brain is already in a certain state – he has these memories of what for him is the past, and what for other characters is the future – and so those thing must happen to justify the current state of his own mind.

So then the puzzle for him to solve is, How can I be wrong?  He knows that his wife will die.  He watched it happen.  He has a memory of it.  So how can he change things so that falling off the roof does not actually kill his wife?

Personally, I hoped he’d use his third trip through that stretch of time to put a mattress on the ground where his wife was going to fall.  But I guess that’s because I’m a softy.  I don’t like tragedy in art.  Which is kind of crumby, because obviously good art is often tragedy.

But the end-of-movie haircut seemed very clever.  He knew his wife died because he saw a woman with his wife’s haircut fall to her death.  But by giving that haircut to the innocent victim, he makes his own memory incorrect, and his wife is saved.

And, really, that’s all.

But isn’t that enough?  Isn’t doing one beautiful thing, presenting one thing in an interesting way, enough to make a great movie?

Also, in case you were interested, the director does interesting things with information sets in the other film I’ve seen of his, Extraterrestrial.  Like, information sets are the things you care about in game theory.  Why, for instance, a car loses most of its value as soon as you buy it and drive it off the lot.  Now you are privy to secret knowledge about how well it works, and a buyer has to make a guess in the dark.

And, anyway, the fact that he’s making these movies seems cool to me – there are directors out there who seem to be fascinated by outlaws, or motherhood, or precipitous camera angles, or by jacket sleeves that don’t come as far down the wearer’s arms as most people think they ought to.  Like, all sorts of things a director might obsess over.  So isn’t it nice that there is also somebody obsessed with information sets?