How ‘3 Body Problem’ Explores The Laws Of Physics

ARIELLE DUHAIME -ROSS: Last week, Netflix released its adaptation of the Hugo Award-winning sci-fi book The Three-Body Problem, written by novelist Cixin Liu. It follows the journey of several scientists from the Chinese Cultural Revolution to the present day as they seek to understand why their scientific results no longer make sense. Along the way, they discover an ultra-advanced VR game and a dark secret that suggests we might not be alone in the universe.
TRAILER: Someone or something is targeting scientists. They’re going after our best and brightest. There’s someone behind everything. You just have to dig.
ARIELLE DUHAIME-ROSS: Just a heads-up, to talk about the science in the show, we do have to reveal some minor spoilers. But we’ll try to limit it to the first few episodes. And I swear the show is still worth watching. Here to tell us more about the science behind “The Three-Body Problem” is the show’s science advisor Dr. Matt Kenzie who is an associate professor of physics at the University of Cambridge. Dr. Kenzie, welcome to Science Friday.
DR. MATT KENZIE: Hello.
ARIELLE DUHAIME-ROSS: Thank you so much for coming on the show. So, Matt, the book and the show includes some pretty complicated physics concepts. We’re talking about particle accelerators, which you work with, nanofibers, astrophysics. When you were asked to be the science advisor, what was your reaction?
DR. MATT KENZIE: Well, I was kind of excited, really, to get involved in the project. I mean, it’s a little bit different from my day-to-day job, which is as a particle physics researcher. And I really enjoyed the book or the book series and lots of the concepts it explores and concepts beyond science in sociology and so on. So I guess, yeah, I was pretty excited to get involved and to see how they were going to try and put this epic novel series onto the screen.
ARIELLE DUHAIME-ROSS: That’s really nice to hear. Had you read the book before you were even asked to be an advisor?
DR. MATT KENZIE: No, I hadn’t, actually. But when I first got contacted by Dan and David, the creators of the show–
ARIELLE DUHAIME-ROSS: And this is David Benioff and Dan Weiss, who ran “Game of Thrones,” and were also the showrunners for “3 Body Problem,” as well.
DR. MATT KENZIE: Right. We threw back and forth a couple of questions and ideas. And then they started asking me for a bit more feedback. And at that point, I thought it would be a good idea to actually read the book. And then I–
ARIELLE DUHAIME-ROSS: [LAUGHS]
DR. MATT KENZIE: –crashed through the whole trilogy in a couple of weeks. I got really, really into it.
ARIELLE DUHAIME-ROSS: Wow. OK. So I got to ask, once you actually started your role as science advisor for the show, did you worry about having to teach the show writers and actors to talk about this stuff accurately?
DR. MATT KENZIE: Yeah. I wouldn’t say I worried too much. I mean, the creators of the show are really smart guys. But I did do a kind of physics 101 or physics crash course right at the beginning. And I had a couple of days around the time they were doing the read-throughs of the scripts with some of the cast. And they asked various different questions about not just the science in the show, but about scientists and how we kind of would approach problems or how we would think about certain scenarios.
ARIELLE DUHAIME-ROSS: What were some of the actors’ reactions to getting these physics lessons?
DR. MATT KENZIE: [LAUGHS] Yeah, it was kind of varied. It was interesting seeing some of the actors not really believing that certain elements of the science could even be possible, let alone realistic.
ARIELLE DUHAIME-ROSS: Right. I mean, some of this stuff is really mind-bending, right? Like, for instance, the three-body problem, right? The name of the show is a famous concept in astrophysics. And I want to ask you about that. I want to know, what role does this problem play in the show? And if you could actually explain it, that would also be great.
DR. MATT KENZIE: Yeah. So as the title suggests, it plays a pretty significant role. In essence, the three-body problem or the n-body problem is where you have any number of objects– more than two– that are all exerting a significant force on each other. And in that scenario, if you know their initial velocities and their starting positions, you can then use the equations of motion to tell you exactly where any of those bodies will be at any point in the future.
But once you have three bodies or more, you now cannot solve that equation.
ARIELLE DUHAIME-ROSS: So the introduction of a third body kind of throws everything out of whack and makes everything hard to predict?
DR. MATT KENZIE: Yeah. So if you could imagine us living in a three-body system or a system with three similarly sized stars that are all kind of a similar distance apart so they’re all exerting a similar-sized force on each other, then you end up in completely chaotic orbits. You do not know when the year is going to end, when the day is going to end. You have no concept of seasons. So that’s the three-body problem.
ARIELLE DUHAIME-ROSS: Ah. OK.
DR. MATT KENZIE: And of course, this plays a really significant part in the show.
ARIELLE DUHAIME-ROSS: What role does the three-body problem play in the show itself?
DR. MATT KENZIE: Well, essentially, something that our physicist characters get exposed to fairly early on is this virtual reality game. And you go into this virtual reality world and it seems to be on another kind of planet or in some kind of different planetary system. And there is very erratic behavior of the sun– or as it transpires, suns in this system. And eventually, the characters work out that this planet goes through these shocking, chaotic eras where the planet will melt or the planet will freeze.
And essentially, what our characters work out is that this game is set in a system with three suns.
ARIELLE DUHAIME-ROSS: Right. So in this game, they’re on a planet. There’s also a species, I think, that’s living on this planet. Which means that species would be living in highly variable conditions, right?
DR. MATT KENZIE: Yes.
ARIELLE DUHAIME-ROSS: Like, apocalyptic on a highly irregular basis.
DR. MATT KENZIE: Right. So that species does very well not to become extinct.
ARIELLE DUHAIME-ROSS: Right. It depicts what living on a planet in a three-body system would actually look like, right? And you had to advise the show on how to translate that for the screen. What details did you decide to include to get that experience of life across?
DR. MATT KENZIE: I mean, we talked about things like, there’s going to be three different suns. And sometimes, they will be very close to the planet. Sometimes they’ll be very far away. And so you can have so many different kinds of sunsets and sunrise, right? You can have a sun that appears very quickly and then plummets away. Or you might have an incredibly slow sunrise that lasts many, many Earth days. And of course, then you can get anything in between where you have two suns rising.
So it’s a perfectly temperate day and then the two suns kind of line up near each other and it suddenly becomes incredibly hot or they then both disappear and it becomes freezing. And the studio, they had this whole massive stage which was surrounded on three sides by this huge screen. Essentially, banks of LED lights covered by a sheet that was– it must have been 10 meters high and 40 meters long or something. And it meant they could just emulate this environment in the most incredible way.
So these scenes you see that are set in the game have these effects where you have double sunrises or low sunrises. And yeah, so it was fun to imagine what these would look like and the color spectrums that you’d get out of that.
ARIELLE DUHAIME-ROSS: We don’t get a lot of shows that feature this many scientists. In particular, this show has a ton of women researchers, which is really nice to see. Is there anything you hope people will take away from the way these researchers are portrayed in the show?
DR. MATT KENZIE: Yeah, I mean, I hope it can be inspirational on some level. But the fact that there are a lot of female scientists in the show is great. There is also a lot of scientists from different ethnic backgrounds, which I think is also good.
ARIELLE DUHAIME-ROSS: And, frankly, realistic.
DR. MATT KENZIE: Yes. Exactly. I think that was a question that I was asked quite early on by the creators, saying, do you think people will really buy that these people are physicists? And I said, well, I bought that they were physicists. Because I think that the stereotype is someone who is quite reclusive and not very good at communicating, et cetera, et cetera. But the reality is that you have to be able to communicate and the people who are successful tend to be quite good at communicating.
And I think also the fact that the characters are kind of inverted come as quite normal. OK. One of them is a bit of a Jack the Lad. One of them is a bit quiet. There are two that sort of have an ongoing romance, but it’s not that serious. And they’re sort of this old group of really close friends. I think that draws a lot of parallels with my experience. So I said I found that perfectly plausible, basically.
ARIELLE DUHAIME-ROSS: Yeah. That’s a very nice thing of you to point out. By the way, this is somewhat off-topic, but I was told that you grew up in a film and TV production family. I think your dad worked on “Game of Thrones?”
DR. MATT KENZIE: Yeah, that’s right. That’s how I got the job, I guess. My dad was the director of photography on the second series of “Game of Thrones.” And so I went out to the set. And at the time, I was part of the team looking for the Higgs boson. And yeah, I met Dan and David, and they kind of indulged me to some sense. And I talked to them for half an hour about particle physics, probably. But I didn’t hear from them then for I don’t know how long. A long time. I mean, my dad has been dead for 12 years now.
So it must have been 12, 14 years later or something that they then reached out to me. They were kind of putting the show together, realized we could do with some advice from a particle physicist. But yes, that was how I got into it. But it’s still pretty different from what I normally do.
ARIELLE DUHAIME-ROSS: Right. Well, it does sound like that makes you the perfect candidate. Dr. Kenzie, thank you so much for taking the time to talk to us about this show.
DR. MATT KENZIE: No problem at all.
ARIELLE DUHAIME-ROSS: Dr. Matt Kenzie is an associate professor of physics at the University of Cambridge in the UK.

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