Well, that was a hugely fun evening! The Cinefamily screening of Primer was sold out to a packed and enthusiastic audience. (That alone was worth it…) I met Shane Carruth back stage for a few minutes and immediately was impressed. I like people who take the time to think carefully about what they are going to say before saying it, visibly carefully weighing what was just said in the conversation and then adding to it in an interesting way. He’s one of those people. So I knew that the panel discussion was going to be great.
We started off with an introduction from the executive director of Cinefamily, Hadrian Belove, who introduced us and asked me to say a few words before the film began. I kept it brief, and started by congratulating Cinefamily on doing the Science on Screen series, saying that it is an important thing to do (which it is -it is part of a Sloan funded national program; more here) and then went on to say how much a lot of scientists I know like Primer. I can’t speak for others, but for me one of the most striking things is how authentic it feels in terms of the depiction of the kinds of conversations scientists/engineers have when they are engaged in what they’re doing. That is rare to get up on screen, as it is often so artificial and “cleaned up” in film. I also congratulated him on writing something that was complex and, yes, confusing. I think it is great to see something genuinely challenging up on screen. I said that it was brave of Shane to do that, and he got a round of applause.
The film started, and it was a pleasure to see it again. I actually watched my copy of it last week, since I had been asked to make comment about it to the New York Times and thought it best to remind myself of it. This was the text I sent to them last week in response to the question about what I was going to talk about in the panel discussion (although they were not able to use most of it):
I’ll be talking about how strikingly true the film is in showing a little of what real conversations between scientists are like, and how they work when involved in discovery. You see real collaboration and gradual, methodical realization, which is a much more human and beautiful process than the tropes of solitude and eureka that you usually see in films with scientists. The scientists are shown confused, excited, a little frightened, and concerned about the consequences (good or bad), which also feels very real. Time travel is a deliciously confusing subject, and it is great that the film is deliberately delicious confusing too. That’s a bold choice on the part of the filmmakers. I’ll also talk about what we understand about the nature of time, and of time travel, in real scientific research today.
Even though I saw it again just last week, it was fun to see it again, and with a good audience (films can be like theatre performances that way – seeing it with good audiences can lift them). As I said later when we started the panel, the film is a gift that keeps on giving since every time you watch it there’s more there to notice, and another interpretation to be made about what you think happened. I like that. I emphasized again that it is great to see a film that has not been over-simplified. It is so hard to get things green lit to be made without it being sent back by executives who express the fear that the audience “won’t get it”… Our culture has a problem if this is the prevailing view, since there are things – many things (maybe some of the things that matter most) – that require several viewings/readings/listenings (etc) to fully appreciate. It’s ok to not get part of something, but to let it wash over you, to sit with it a while and let it soak in over time. I was happy to hear that the audience agreed with this, and they made it known.
We touched on many things in the panel discussion, and got lots of great questions from the audience, some for Shane about writing and filmmaking, and some for me about physics and time travel and so forth. I kept finding analogies between, on the one hand, the physics and on the other hand, of him remembering his process of writing the film, and of other aspects of making the film.I think it helped illustrate the whole business of the physics of time travel. That sounds strange, I know, but there it is. Let me take one aspect. At one point during an answer about process, he was apologizing, in his thoughtful way, for maybe giving an overly neat narrative about how he arrived at his ideas and put the film together, and that probably the full story was maybe much more complicated and less deliberate at times, but he can’t recall all the details. I responded to that point by saying that was just fine. That’s often how it is… in memory and reflection about the past, we need a narrative arc (sometimes a simpler one than the reality of things) that makes sense to us in order to organize and rationalize what we did, to make sense of how we got to a certain place. In order to articulate remembered sequences of events to others (and perhaps even ourselves) we need to hang it on a sensible narrative to some extent. Perhaps this is how the classical laws of physics (where there is a simple, macroscopic thing we call time with a definite forward direction) work out too, even though microscopically there’s a much more complicated story going on involving summing over all sorts of quantum paths and histories…. and maybe even things that would be interpreted as closed timelike loops if we were to look closely. So in the end, lots of “strange” physics is allowed -including what might be interpreted from some perspective as time-like loops- as long as the top level narrative makes sense – as long as there’s a paradox-free narrative… Well, that’s a bit of what I was getting at.
We also talked (at Hadrian’s prompting – he leads discussions very well) about what I thought of the physics, and of the physics in lots of science fiction. The issue of it being right or wrong. There, I spoke of the need for less focus on whether the physics is right or wrong in some absolute sense (but of course, it is important not to mislead the audience) and more focus on what it’s there for in the first place – it’s often not about the science (in some of the best science fiction, for example) so much as about the opportunity the science gives to explore stories, relationships, internal journeys, etc. The stuff of being human. So I talked more about wanting whatever science is there to at least be internally consistent so as to not just make you feel like you’ve wasted your time (as so often happens when bad writing just resorts to messing with the rules – or making up last minute ones – to “fix” everything)… If there was a focus on how the science is coming off for its own sake, I said, I’m usually most concerned that the scientific process is shown, since that’s the aspect of science that’s most central to communicate to a wide audience. (It is of course fun and satisfying to see when a lot of details of some science area of other make it up on screen in good shape, and it is great when that happens, and provides opportunities to show what’s going on in a field, but one has to be careful to not think that’s always the point.) I mentioned that my teenage self would have obsessed more about whether the science in some movie was right or wrong, but, you know… you grow up and realize what’s really at stake.
Shane spoke a lot about the business of using science as an opportunity for writing avenues too. He spoke about ways of giving characters power over each other, opportunities for conflict, and so forth. That in another era, a writer would have used (for example) the powers of the Gods of the day as the setting for their drama. Our current understanding of the universe through science is a modern writer’s setting for their drama.
(By the way, he also talked about his new upcoming film “Upstream Color” a little bit, which sounds like it will be fascinating.)I did get an opportunity to try to explain about where research into the matter of time travel is right now, and the various camps into which people find themselves. I won’t go into it here, except to say that (having a patient audience who does not mind getting into the depths a bit) I did a description of Special and General Relativity, and explained how making a time machine is consistent as a solution of the equations of GR, but then the issues start about how you would go about making such a solution (can the kind of matter required even be assembled?), how much energy you’d need (probably a forbidding amount… although I threw in the possibility that maybe Nature made some and we just need to find them and not need to manufacture them), and then whether or not it is all consisten quantum mechanically (it seems to not be, in a broad class of semiclassical computations). There’s the issue of whether Nature forbids closed timelike loops completely (Hawking’s “Chronology Protection Conjecture” is the term people like to bring out in these conversations) or whether they are allowed but somehow the laws of physics prevents paradoxes from appearing (which then raises issues of free will, etc…). (I recommend the writing of Kip Thorne as a good source, for example his book Black Holes and Time Warps. See also some web material here.)
The bottom line is that the jury is out until we get to grips with how to answer these questions in a complete (and tested) theory of quantum gravity (whether it be string theory or some other theory). (Actually, I was put in mind of my own paper on this that I wrote in 2004 with Harald Svendsen. I’ve not looked at it in many years, until yesterday, and I got sort of excited by it all over again. I really like it. It is a way of embedding a model of closed timelike loops in a string theory model that allows you to control at least one class of string theory corrections to all orders…)
Well, anyway, it was a great night, with conversation continuing well after the Q&A in the auditorium, and then with a group of friends over drinks in the nearby Rosewood Tavern for another hour or two.