Time Travel Movies

And how would you describe Heinlein’s classic story “All You Zombies”? Of course it’s not a movie, but it ought to be.

Not to be anal or anything, but Marty does not play in a Huey Lewis cover band. Huey is the judge who tells Marty that his band is “just too loud” to play the school dance. The only song Marty actually plays in the movie is “Johnny B. Goode.” The bandleader, who is supposedly Chuck Berry’s cousin, calls him (Chuck) up to tell him about this great new song. This brings up the question of where exactly the song comes from, if you like those sort of silly philosophical time-travel questions. Which I guess you do.

I only saw the first movie, but I have fond memories of catching the most pompous professor in my department coming out of BTF III at the theater. Listening to him try to explain his “interest in the level of current popular culture.” is one of my fondest memories of grad school.

Ahem. Marty plays for Huey Lewis as a judge. But what he and his band play appears to be a thrashed-out version of the opening chords to “The Power of Love,” though this is far from explicit.

If you’re not teaching “Timecop,” your students are missing out. Also, don’t forget that John Woo’s terrible version of the time-travel story “Payback” is coming out.

Don’t forget “Bill and Ted’s Excellent Adventure.”

I’m serious!

–Kynn

Note to self: remove Brown from list of schools to consider for children.

let me second the motion on bill and ted’s excellent adventure. near the end of the film, when the heroes realize that they need something, they decide that in the future they will travel back in time and leave it for themselves to find. they then go to the spot they plan to drop the item and discover that it is there.

i always wanted to have that power.

Thanks Kieran!

Actually much of the course will be about general issues about the role of time in classic philosophical problems – like whether the past and future are real, what (if anything) is wrong with the argument for fatalism, whether free will and determinism are compatible, how many concepts of possibility we have in our folk conceptual scheme and whether we can say something substantive about personal identity across time. There’s plenty of other philosophical issues we could get into – the nature of causation, the aesthetic issues raised by incoherent stories, etc. If anything the problem is that the course will end up being too unfocussed, too much like a week-of-everything-intro course. In any case, I certainly don’t feel bad about making some effort to make these topics interesting to as many students as possible.

I am fairly dismissive of the many-worlds interpretation (largely because I’ve never seen a good account of how we generate the _probabilities_ distinctive of QM in the many-worlds account), but really I don’t think it’s particularly relevant to time travel. What might be relevant to time travel are Godel’s models for general relativity that include closed time-like curves. Of course, it doesn’t look like our world is particularly like any of those models, and time travel in such a world would be, at best, prohibitively expensive, but it is at least relevant in principle. Still, it’s hard to see how the existence of such a solution to GR is relevant to the issues about fatalism, free will, personal identity, etc. that are the main _philosophical_ focus of the course.

Keith – don’t be so quick. The “note to self” was not too harsh. I was at Browm (for a grad degree), and would never, ever recommend it for an undergraduate education. It is a University that has consciously made the decision to trade academic rigor for a summer camp atmosphere, on the belief that graduates will remember the latter more fondly and demonstrate that through their donations. To be fair, it is once again “under new management,” but it will take a while for the effects to wear off and the boutique courses (“Hard Choices” et al.) to disappear even if the new leadership charts a different course.

May I suggest watching Donnie Darko. While following a many-worlds theory, it has a couple interesting insights into perhaps the choices one would make given the knowledge of time travel.

Sounds like a cool class. When I have room in my schedule next year, I’ll travel back in time to audit it.

Re: Back to the Future. The best line is a throwaway about Miami winning the World Series in 1997, which did in fact happen, even though Miami didn’t even have a baseball team when the movie came out.

Time travel stories I take to be, and yes, occasionally teach about (strike Swarthmore off the list too, I guess) as a kind of thought-experiment about causality, and they’re kissing cousins in that respect to more formal counterfactual writing in history and other social sciences, and even to social scientific exercises in model-making that isolate a single variable and “test” its importance by subtracting and adding through manipulations of data sets.

Time travel stories are in that respect no different than the kind of (absolutely crucial) philosophical and theoretical discussions that begin with “Suppose we had no senses whatsoever: what would we know about the world?” or “Suppose a man was stranded on a desert island with no human companionship: what would he become?” or even “What were people like before they lived in settled communities?” This is the kind of thinking without which Western philosophy, historiography, literature and science could not have existed. You could imagine a time travel story where the time traveller travels back and eliminates the idea of the time travel story and that might change everything!

To deal with the issue raised about Back to Future, though, that type of time travel story commonly uses a “perspectival exception”, meaning that the traveller himself is exempted from being enmeshed in the changes his actions introduce into the world by virtue of his participation in those actions.

There’s a variation on that formula where there is a sort of amnesiac wave that catches up with the traveller once he returns to a changed present, eradicating his awareness of the transformation, but this is commonly used only when the time travel is “restorative”, meaning it is undertaken to move events back to a status quo state after some other traveller has moved them onto another causal branch.

What I would say is that you’ve identified something that is perishingly rare in the entire genre of time travel stories, which is a traveller who returns to a changed present and is not changed himself where the consequences of the traveller’s lack of being “native” to the new branch of time are then explored.

E.g., it doesn’t strike me as intrinsically weird that Marty should return to a new branch of his present and still be the “old” Marty. What strikes me as weird is that the “old” Marty should be able to live comfortably in the “new” branch–every detail of his life within his family should be completely unknown to him, and in very short order, he should be exposed as a kind of imposter or changeling, or an amnesiac.

Very few time travel stories explore those kinds of issues. Which in the end has to do with the underlying hypothesis that a story like Back to the Future is making about causality: it proposes that its protagonist’s character at the *outset of the story* developed individually, an aberrational exemption from his family and surroundings, and therefore, a change in his surroundings does not change him, it only increases his comfort level within the world. Marty is already outside the causal loop of his world before he ever travels in time.

I’m not familiar with Heinlein’s story “All You Zombies,” but I can attest that his story “By His Bootstraps” that he published under the pseudonym Anson MacDonald is excellent.

My favorite time travel story is one from (outer limits or twilight zone, don’t remember which) where a woman goes back in time to kill hitler. She becomes the nanny for the hitler family, kills the baby hitler. Then, she goes out and gets a kid from a poor woman on the street and replaces the original baby.

Well, this new baby is hitler and the other baby woulda just been a normal guy.

I think that is the most coherent type of time travel, where there aren’t two different timelines.

John Wyndham wrote a number of good time travel stories: “Opposite Number” from the “Seeds of Time” collection explores the branch theory (using the comparison with quantum mechanics) and “Chronoclasm” has fun with the whole idea of inventions that are never actually invented – because someone from the future shows the “inventor” how it’s done, using information that originally came from the inventor.

I didn’t know anyone had actually made a case for Terminator 2 making sense – I always felt the difference in coherence between that and the first film showed how success has allowed James Cameron to get away with increasingly nonsensical plots.

Bonus points to flicks like 12 Monkeys for taking a decent intellectual stab at time travel, but a close viewing of even that film reveals logical inconsistencies that cripple its approach (of course, throw in the suspension of disbelief you need for just about any work of fiction, and it’s a great watch – better than the vast majority of stuff out there). I have yet to see a fully fleshed-out theory of time travel at all, let alone one not reliant on physics sleight-of-hand. Frankly, having studied some physics and QM in university, it seems to me that modern cutting-edge physicists often have little real comprehension of the processes underlying their research, instead substituting analogies and metaphor as alternatives more palatable to the layman’s understanding. It raised the disturbing question of whether or not the physicists really understood what was going on, or whether they simply attempted to grab the first working system that floated by.

I’ve never been to Brown but i’d like to play devil’s advocate in response to tim’s anecdotal report on his experience there.

Brown is a respectable 17 on the annual US News report, and according to Brian Leiter’s Philosophical Gourmet it’s tied with Yale, Cornell, and The University of Chicago for 16, at 3.4 in its overall ranking of American philosophy departments.

To give an idea of what that means, I am a student of the University of Toronto which has an overall rank of 3.5 (pretty much the same as Brown, but for reasons peculiar to the method of the report probably worse) and next semester I’m taking classes with both Ian Hacking and Thomas Hurka, two very good philosophers. I expect the case for students is the same or better at Brown.

And if the US News Ranking is indicative of anything, Brown in general is certainly not in the same league as Timbuktu college; not that anyone was implying that, but you get the point.

Sounds like a cool class. When I have room in my schedule next year, I’ll travel back in time to audit it.

Why would you need room in your schedule?

I have a theory, based in part on a general sense of Terry Gilliam’s approach to these things, that 12 Monkeys does not present a one-dimensional timeline. It’s at least possible that the man we see in the yellow coat in memories early on is not the man we see in the yellow coat in present time at the end – that the time traveler succeeded in changing the past in ways that neither he nor anyone else ever recognizes.

The anime series X, now up to six discs out of, um, thirteen or so, has some very nice stuff with prophecy and destiny, and the limits on each. It’s supernatural, of course, rather than strictly scientific. (Yes, I do realize this is far too long for a class.)

For the thorough-going mindfuck, there’s always David Lynch’s film Lost Highway. Now of course it’s got a literally incomprehensible moment smack in the middle, but it seems to play out quite smoothly all around that if it’s taken as a given.

Minority Report is worth mentioning if you bring up the possibility that, just as we were told the prisoners all do, the protagonist is dreaming in his confinement of the perfect or at least an acceptable outcome.

Donnie Darko’s a delight, and one of the most thoroughly Phildickian movies I’ve seen.

I’d definitely like to second the recommendation of “Slaughterhouse Five.” I’m actually teaching it this semester in a course that has nothing to do with time travel, but for a time travel course, it’s spot on.

12 Monkeys is also a necessity. In terms of consistency alone, the best time travel movie ever made.

I’d like to comment briefly on the Missing Marty problem. You might not remember, but the “missing Marty” is seen going back in time to 1955 at the very end of Back to the Future Part I. So there should be only one Marty at the end of the movie, because the one who grew up in that timeline is gone.

But there’s still a problem. If the Second Marty can’t possibly do everything that the first Marty did because he starts with different information. He doesn’t know that Biff is a bully who runs/ruins his dad’s life, and he doesn’t know the original story of how his parents yet. (He doesn’t know the birdwatching story, for instance.) Because of this it may not even occur to him to intervene until it is too late.

BTTF therefore gives us a sort of endless loop where a Marty goes back and time and mucks around in 1955, only to return to the future moments before the New Marty heads back in time to change everything around again.

Marties would spring up into existence and then replace themselves forever until finally the universe hit upon a successful, self-causing, self-consistent pattern.

Connie Willis has written a couple of time-travel novels using the notion that time travel is achievable, but a physical property of the universe prevents actions that would foul the timeline. Thus, a traveler by definition cannot get close enough to major events to affect them (in one book, researchers trying to visit the bombing of Coventry keep winding up in turnip fields outside the city at several days’ remove). History, in her conception, is robust, with small perturbations collapsing back into a timeline that is unchanged overall.

Also, another consequence of her theory of time travel is that time travelers cannot bring objects forward from the past. Because of this, after an initial flurry of interest in the technology, the corporate world gave up on time travel as a money-making proposition, so that it is now wholly the province of underfunded university researchers. The crowd on this weblog might particularly enjoy that aspect.

Her first such book is Doomsday Book, about a creepy and tragic visit to England at the outset of the Black Death. Her second is To Say Nothing Of The Dog, an immensely funny Victorian-era comedy of manners, which actually hinges on the fate of a cat. The restraints built into her theory of time travel make for intricate (and generally coherent, I think) philosophical and practical puzzles, especially in the second book.

This bit gets awkward, but it is consistent with 1D time that a time traveller could go back and cause or prevent an historical event. It’s just that it must be the case that the even they cause (prevent) was (not) part of the history they were already in.

If there was an oddly knowledgeable kinda nerdy red-haired Australian who played a crucial role in stopping the Cuban missile crisis turning into WWIII, then I could go back in time and be that very Australian. And since he prevented WWIII, that means I could go back in time and prevent WWIII. Indeed I better, because if I hadn’t there would have been a nuclear war in the 1960s, and we wouldn’t be here. (If you prefer you could go back and lobby for all the treaties that led to WWI. I might try and kill you though if you’re going to, just on general anti-WWI principle. Whether I succeed will depend, inter alia, on whether it really was you who did that 1910s lobbying.)

It’s really hard to think about these cases, because all of our normal ways of thinking about causation involve it propagating forward through time, and the idea of time travel is that there can be backwards causation.

Some people think this means time travel in 1D time is incoherent. (See, for example, the site gc mentions, which has some rather weak arguments to that conclusion.)

I’m much more inclined to think that, as David Lewis said, the correct conclusion is that a world with 1D time travel would be radically different to the kind of world we normally think we inhabit. Since QM already tells us that the world we do inhabit is radically different from the one we think we do, it’s hard to know just how big a strike against time travel that is.

I was going to spend some time on that argument, but I realised I didn’t have a whole lot to say about it. Here’s two things one might say:

(1) We have met time travellers, they’ve just been very well disguised. There are some books that take that line, but it’s obviously not the most plausible thing in the world.

(2) It turns out the only kind of time machine that is feasible requires you to put some part of the machine at either end of the travel. It’s like a telephone – you can talk across long distances but only if there’s a machine of the right kind at the other end. When the first of these machines is built it will be possible to travel back to it, but since there is no such machine in 2003, no time travellers in 2003.

Option (2) looks suspiciously ad hoc as a solution to the ‘no time travellers’ argument, but I’ve met a few people who take it seriously.

As for what it reveals about the students who bring it up – perhaps just that they read the textbook because it has a moderately long discussion of this puzzle, including stories that follow option (1).

If the course is hot limited to movies check out Poul Anderson’s time travel stories.

Jack Finney’s first time travel book Time and Again is also a must (but not the sequel).