If you enrol for a physics class at the University of Central Florida, you may be in for a big surprise. Instead of being sent to the campus bookshop to buy course books, you’ll be directed to the local video store to rent a few DVDs. The directors of this class, Costas Efthimiou and Ralph Llewellyn, believe they have hit on a novel way of getting non-science students not just to bury their hatred of physics but to embrace the subject with enthusiasm. Marcus Chown talked with Efthimiou about the course that he says is designed to challenge the pseudoscientific ideas propagated by the entertainment industry – and to show students some of the joys of physics.
How did you come up with the idea of teaching physics using movies?
In 2001 I was given the task of teaching physics to several hundred students at the University of Central Florida who were not majoring in the subject. The students simply did not get what I was teaching. In fact, I was taken aback by their aggression. The whole thing was such a miserable experience that when I was asked to teach the course again I said no – unless I was able to try something new. For a while I’d had this idea in my head about using films to teach. I was also aware of Lawrence Krauss’s best-seller The Physics of Star Trek [Flamingo, 1997], though I hadn’t read it at the time. I talked to Ralph Llewellyn, who had been teaching physics to non-science students at the university for a number of years, and we decided to give it a go.
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Are you trying to make scientists out of the students?
No. Our goal is to show the students, and the public, that science is fun and entertaining when expressed through popular activities. We also want to promote science literacy and attack pseudoscientific beliefs that have been gaining ground over the last two decades. Research indicates that the entertainment industry is partially responsible for this trend. Our course is a way of challenging ideas that the industry presents about the supernatural.
What does the course involve?
Before each class, we ask the students to rent a video. They’re perfectly happy to rent 10 videos at $4.50 a time over the course, whereas before they were reluctant to buy a single book. At home, they watch the video, pick three scenes where they think physics plays a role, and write a paper on whether they think it’s realistic or not. It doesn’t matter whether they are right or wrong. The point is to get them thinking rationally about what they are viewing. When they come to class, we replay the scenes and discuss them.
Can you give me an example of a scene from a film and how you use it?
One of the films we use is Armageddon, one of the worst films ever made. An asteroid is on a collision course with the Earth, and NASA sends Bruce Willis to the rescue. He drills a hole in the asteroid and plants a nuclear bomb there that splits it into two fragments which miss the Earth. We get students to work out whether this is realistic, based on data presented in the movie. First they estimate the asteroid’s mass. Then, using a reasonable assumption about the size of the explosion, they estimate the deflection speed of the fragments. Finally, they estimate the time it would take for the fragments to collide with the Earth and the distance they are deflected during this period. What they discover is that all Willis would really manage would be to create two asteroid fragments that would hit the Earth about two city blocks apart.
It’s quite a sophisticated calculation that involves applying two principles: the conservation of momentum in two directions – parallel to the trajectory of the asteroid and perpendicular to it – and the conservation of energy. We call it a Fermi problem, a back-of-the-envelope calculation characteristic of the physicist Enrico Fermi, who famously dropped a scrap of paper at the first atomic bomb test in 1945 and from its horizontal deflection estimated the blast at about 10 kilotons of TNT.
Are there other Fermi calculations you can do from movie scenes?
There’s another scene in Armageddon where they generate artificial gravity by spinning the Mir spacecraft. The problem, as the students discover, is that this doesn’t work because the amount of artificial gravity generated by centrifugal force varies widely from one part of the space station to another.
This doesn’t happen in the pinwheel space station in 2001: A space odyssey because everyone lives in the rim of the wheel, where the centrifugal force due to rotation is the same everywhere. You can estimate the size of the wheel – about 100 metres across – as you can see people in the windows. Combining this with the spin rate, which you can also estimate from the film, gives you the artificial gravity, which turns out to be close to 1 g. Stanley Kubrick and Arthur C. Clarke were careful to get things absolutely right. Unfortunately, students find the film impossible to watch because of its lack of dialogue.
What other types of films do you use?
We’ve developed several different flavours of our course. One is science fiction. We also use action films such as Eraser or Tango & Cash or Speed 2: Cruise control. But we get far and away our best response from students when we use pseudoscientific films such as The Sixth Sense and White Noise. There seems to be a deep-rooted belief in things like extrasensory perception, vampires and crop circles, which is difficult to shift. From the feedback we get from the students we know we are making them more sceptical, and the debate in class often gets so furious we have to step in and call a halt.
“The debate in class often gets so furious we have to call a halt”
Does it matter that Hollywood gets it so wrong in modern science-fiction movies?
No, I don’t think it does. What I do think is seriously dangerous, though, is when movies portray pseudoscience – everything from telepathy to remote viewing – as real. I tell the students that physics is stranger than pseudoscience but they are attracted to pseudoscience and repelled by physics because the former requires no work and the latter does.
What do your students think of the course?
The response is very positive. Some say: “I would watch movies anyway, but now I’m getting credits for it!” Others complain that they can’t watch movies for enjoyment any more – they end up analysing scenes for how realistic they are.
What are the best and worst movies as far as the physics is concerned?
Contact, based on the Carl Sagan book and starring Jodie Foster, is pretty good. It gets all sorts of stuff spot on, including the physics of wormholes. The worst film is The Core, in which a US military project stops the outer core of the Earth rotating. It has to be restarted with nuclear bombs. There isn’t a minute in that film where the writers haven’t rewritten the laws of physics.
Profile
Costas Efthimiou obtained his BSc from the University of Athens and his PhD from Cornell University. Since August 2000, he has been at the department of physics at the University of Central Florida. Two years later he developed the “Physics in Films” course with Ralph Llewellyn in an effort to revitalise the traditional physical science course that is offered in almost every university and college in the US. It has been in continuous development ever since. For more information see their paper at .
