Physics in Film

I really like this movie; it’s the closest any feature presentation has come to showing what the life of an astronomer is really like. That’s probably because the movie is based on a novel written by the eminent astrophysicist Carl Sagan, and some of the characters in the story are based loosely on real life astronomers (Jodie Foster’s character is supposedly based loosely on the life experiences of an astronomer named Jill Tartar, and there really is a blind astronomer named Kent Cullers who worked for SETI). Besides that, though, I think “Contact” presents some compelling plot lines, most crucially the question of what really would happen to our society if we made contact with an alien civilization. It also addresses what many see as a conflict between science and religion.

I was surprised when doing some quick research for this review to find some feminists who complained about the portrayal of Jodie Foster’s character (example here); personally, I found it refreshing for presenting a strong, smart, motivated female lead character. OK, so she had some emotional issues, but do we really expect her to be perfect?

Anyway, the movie is also great because it really tries to get as much of the physics right as possible. The opening sequence has a problem with the scale of objects and distances, but it at least has everything in the right place. The idea that another intelligent civilization may discover our existence by capturing stray radio transmissions from Earth is also sound. That’s how we’re hoping to discover them after all! And wormholes (if they’re real) are our best hope for accomplishing interstellar travel in a single lifetime. However, with all its scientific successes, the movie plot does have one glaring flaw…

Assignment: Toward the very end of the movie, we are presented with a version of the “Twin Paradox.” I want you to point out what is wrong with the portrayal in the movie and come up with a revised movie script that gets this point right.

Please post on your blog by Monday, 17 Nov.

Man, some of the Star Trek heroes are looking old in this one. No wonder the brand moved on to making “Next Generation” movies.

In my opinion, this isn’t one of the best Star Trek movies; it’s a little too cheesy and there’s too little action for my taste. Still, the movie plot is built around a great irony – having to crew a salvaged enemy vessel back to Earth for your own courts martial is fantastic. That’s almost like sticking a bunch of Taliban enemy combatants in a Navy battleship (by themselves) and instructing them to sail to Guantanamo to await trial. I wonder where that ship would end up. In the world of Star Trek, though, persons must have a much stronger sense of justice because the crew does exactly as they are told. That is, until they arrive at Earth and find it under attack from some sort of alien probe. Here Kirk’s crew disobeys an order basically telling them to save themselves and get away. Instead they risk their lives to save planet Earth, and in so doing, guarantee that their trial can proceed. Of course, all ends happily (and predictably).

Still, Star Trek is a great franchise to study in a “Physics in Film” class. As with all great science fiction, Star Trek did its best to weave great science and great fiction into a very imaginitive tapestry. Many of the technologies introduced in Star Trek were predictive of technologies we already have today – the communicator devices in Star Trek are earily similar to push-to-talk cell phones that are commonly used by businesses today. Other technologies in the series are likely many centuries away or even impossible. But even here, the Star Trek series tried whenever possible to stay within the realm of things that were at least physically plausible based on our current understanding of science. Only a few of the technologies are the stuff of pure fiction.

Assignment: Most of the technologies introduced in the Star Trek series were necessary to fulfill one plot requirement or another. There were very few gratuitous technologies, which is consistent with how new technologies are really developed. Necessity is the mother of invention, after all. So what I want you to do for your assignment this week is to explain the plot need behind two of the technologies in the Star Trek series. For your first technology, I want you to consider the “warp drives” on the USS Enterprise. Why was the warp drive a necessary plot device in Star Trek? Remember, this is a physics question. So discuss what some of the physical limitations were, based on what you already know, and why it was necessary to go beyond current technology. The choice for the second technology is yours, but I’d like for you to talk about why the technology was necessary for the plot and what the feasibility of the technology is in the real world.

I’ll admit I was a little disappointed when I watched this movie. Although it does a good job of recreating many of the elements of the Manhattan Project (most of the factual occurances in the movie are true, or at least reasonably close to the truth), I thought the portrayal of the characters lacked any real depth. This was particularly disappointing for me because each of the past two summers I have read biographies of two of the scientists involved in the Manhattan Project, Robert Oppenheimer and Richard Feynman. I can assure you both men were much more conflicted, quirky, brilliant, and interesting than they were portrayed in the movie. Nevertheless, the movie manages to convey the main dilemma I want you to comment on in your blogs this week: the morality of having scientists design and build weapons of mass destruction. Many scientists who do this hide behind one of the moral shields presented in the movie: the scientists are only responsible for developing the weapons, not using them. Other scientists openly embrace their role. Edward Teller was one prominent Manhattan Project scientist who felt that the only way to keep the world safe was for the United States to have weapons of such terror that no other nation would dare to step too far out of line. Even after WWII ended, Teller advocated further development of atomic and then nuclear weapons. In a very real sense, he was the architect of America’s modern nuclear arsenal. Still other scientists have felt that there is no way to divorce the results of such weapons’ use from their development, and therefore have refused to work on weapons-related research. (Sadly, the right or privilege NOT to work on weapons-related research is not always afforded to scientists.)

Assignment: This week I’d like for you to just write about the movie. I want you to record what you think and feel as you watch the story progress. You might want to comment on the drive and ambition of the military officer, General Groves. You might want to comment on the gradual shift in the moods of the scientists from ebullient enthusiasm and excitement to gnawing guilt and remorse. You might want to comment on Dr. Oppenheimer’s “God complex”, the notion that he could control everything around him. There are many other themes you could choose to comment on as well (I don’t really need to hear your comments on the love story unless you just can’t resist talking about it).

Alternative assignment: If you attend the Festa Lecture on Monday, Nov 3 (see entry below), then you can instead write a blog entry summarizing the main points of Dr. Roble’s talk, particularly as they relate to this course.

Please post your blog by Tuesday, 4 Nov.

I had asked the library to get a copy of the original “Godzilla” (1954), but it appears it was easier for them to get a copy of the much more recent remake (1998). It’s not really that I thought the original (which I still have not seen myself) would be a higher quality movie (Godzilla was, after all, one of the stalwarts of 1950’s era B-rated sci-fi flicks, so you have to appreciate it for what it is). It’s just that the original (Japanese) version made a little more of a political statement about the effects of nuclear testing and the nuclear age in general. The more recent version sweeps most of the politics under the rug (blaming the French instead of the Americans for creating Godzilla, for instance) and appears satisfied to just be a corny monster movie. I could live with that except that our goal this week is to consider the role movies play in shaping and reinforcing people’s opinions about scientific issues. Nuclear power is one such issue. By some estimates 27% of Americans say they fear nuclear power, even though a far smaller percentage actually understand it at even a rudimentary level.

Assignment: Write a blog entry on how you perceive nuclear power. Do the pros of: 1) relatively cheap energy and 2) energy independence outweigh the cons of: 1) nuclear waste disposal and 2) safety concerns. What factors have influenced your thinking? What about nuclear weapons? Do you feel they have a role in modern warfare or are they too devastating to actually use? Do you favor the development of “tactical” nuclear weapons (low yield devices intended for use on the battlefield) or is that too likely to provide further impetus for other countries to develop and use nuclear weapons? Movies about nuclear armageddon were popular during the Cold War, but the theme has fallen out of favor in Hollywood in the last couple decades. Do you think a nuclear holocaust could happen in today’s world? Under what scenarios?

Please post your response on your blog by Monday, 27 Oct.

There is plenty of bad physics in this movie, just like “The Core”. Enough that we could make another assignment of just trying to find as many examples as we can. Instead, though, I want to shift gears a bit with this assignment. Rather than looking at a bunch of different specific examples of science in this movie, I want you to focus on the overarching science in the movie – that of global warming. Clearly this is a controversial issue, at least among the public and politicians; scientists are mostly in agreement about the problem, although not necessarily about the potential impact or how to solve it. One of the problems seems to be that, although the bulk of the reliable scientific evidence points toward the reality of global warming and man’s role in it, there are occasionally studies released that appear to contradict this conclusion or scientists who are willing to speak out against this conclusion. However, none of these counter-claims has ever been able to produce as compelling and large a body of evidence against global warming as that in support of it. The naysayers only a few small anecdotal pieces of evidence that seem to point the other way. For unscrupulous politicians and others who have vested interests in the status quo, however, this is usually all they need. People (particularly non-scientists) are willing to discard mountains of evidence that go against their opinions in favor of a much smaller body of evidence that support them. This is a very illogical way to make decisions, but it happens all the time. This is a great week to discuss this issue because on Thursday, during class, Dr. Terry Richardson from here in the Physics department will come in to lecture exactly on the topic you are to be writing on – the science and policy of global warming. Also, on Thursday at 12:15 in our usual classroom, the Physics Colloquium speaker will be a former CofC graduate who now works as a Regional Climate Extension Specialist, whose job it is to try to bridge the gap between the science of global warming and the policy. I encourage all of you to attend that talk if you can.

Assignment: Analyze and discuss the movie “The Day After Tomorrow” from the perspective of how did/does this movie and others like it affect public discourse and opinion on the topic of global warming. Does the movie present any compelling and accurate information or arguments? You may also want to consider the role that documentaries, such as “An Inconvenient Truth”, play. Is there any evidence that either of these movies affected public opinion? Is that a good thing or a bad thing?

Bad physics:
1. The wavelength (and speed) of sound changes when it passes from one medium to another, but not the frequency.
2. Birds don’t have enough mass or fly fast enough to have the momentum required to break through a piece of glass.
3. The shuttle does not spin around nearly as quickly as portrayed. The amount of angular momentum involved would require a huge (and perfectly timed) thruster burn. The real thing would be done much more gradually. You’ve watched NASA television, right?
4. The Earth does not have an electric field, only a magnetic one.
5. THE BIG ONE: Angular momentum conservation requires that if the Earth’s core stop spinning, something else must take up the angular momentum lost by the core. In the movie angular momentum apparently can just disappear. I don’t know if the movie’s numbers are right, but the movie even claims that there are “a trillion tons of hot metal moving at 1000’s of miles per hour”. That’s a lot of momentum.
6. OK, another big one: conservation of mass. What happens to all the matter that makes up the rock that the laser obliterates. Even if the laser completely vaporizes the rock, that vapor has to go somewhere.
7. An explosive charge inside the Earth would not restart its rotation. Again, conservation of angular momentum must apply and angular momentum can only change whenever a torque is applied. An explosion inside Earth would not create a torque.
8. When they break through the “geode” the terranauts would be in freefall. They would “float” like astronauts, not dangle in their seatbelts.
9. Not quite sure how walking from compartment to compartment works with the whole gimbal system…
10. Microwaves don’t fry the planet, though they are pretty useful for making a quick bag of popcorn. Also, your cell phones work in the microwave band. They are not particularly harmful and certainly the intensity of microwaves from the Sun is not enough to do any damage (microwaves make it right through the Earth’s magnetic field and atmosphere, anyway).
11. Just having some extra plutonium around is not going to make a nuclear bomb stronger.

Obviously I let a few bad physics examples pass. I tried to just concentrate on some of the really big ones.

Good physics:
1. An electromagnetic (EM) pulse could disrupt all electronics within some specified radius. However, the only weapon that is known to create an EM pulse this large is a nuclear bomb, which creates many things other than just an EM pulse. [FYI, a supposed prototype EM pulse weapon was used by Ocean's gang in the movie "Ocean's 11" to knock out the electricity in Las Vegas.]
2. Earth’s auroras are the result of the interaction between the solar wind, the Earth’s magnetic field, and the Earth’s atmosphere. Changes in our magnetic field would affect the auroras over time.
3. The Earth does have a crust, a mantle, and a core made of two components: a solid inner core and a molten outer core.
4. The deepest humans have ever penetrated inside the Earth’s surface is 2 miles (significantly less than the 7 miles claimed in the movie). The point, though, is that we have barely even scraped into the crust. The mantle goes down to a depth of 1800 miles or so, hundreds of times deeper than we’ve ever gone.

Good/Bad physics:
1. Some birds do navigate using the Earth’s magnetic field. However, this is for long-distance navigation, not to fly around in a public square. I doubt birds would suddenly start flying into objects even if the Earth’s magnetic field suddenly changed (birds can see after all).
2. The solar wind is not “radioactive particles and microwaves”. It’s made of ions, protons, and electrons. But the Earth’s magnetic field does deflect the solar wind away from the Earth.

This is another movie we probably won’t officially review this semester, but I wanted the library to have a copy on hand. For car enthusiasts, it’s probably a must-see. For a physics class, you might think there’s not much to work with here. To some extent that’s true, but the movie does have one great physics scene: a 120 or so foot jump of a 1967 Shelby Mustang GT over the top of a traffic accident on the Vincent Thomas bridge in Los Angeles (view a clip of this scene on the Nicholls State U. website here). In the context of a “Physics in Film” class this scene is remarkable for one particular reason: it serves as the perfect contrast to the infamous bus jump scene in the movie “Speed” (view clip here). In “Gone in 60 seconds” the jump is depicted in a physically plausible (if highly dangerous) way; the car takes off with an appropriate launch speed and angle to make the jump and follows a realistic trajectory (we’ll analyze this scene in class), whereas the jump in “Speed” is not at all possible as portrayed in the movie. “Why does it matter?” you may ask. Maybe it doesn’t, but I would counter with the question, “If you can do the scene realistically and still make it exciting, why wouldn’t you?” For me, the scene in “Gone in 60 seconds” left me feeling “Wow!” The danger of the jump fits in with the plot – Randall Raines (Nicolas Cage) has already demonstrated he’s willing to give up everything (even his own life) to save his brother. If it’s going to take a nearly impossible jump over a log-jam of cars and emergency vehicles, so be it! The scene in “Speed,” on the other hand, left me feeling, “Oh, come on.” The plot is ludicrous as it is (a psycho ex-cop decides to hold a city hostage by booby-trapping a transit bus?), but the bus jump scene pushes the movie completely outside the realm of possibility. That’s not what I’m looking for in my action movies. So, my question to you is, why do Hollywood directors choose to film impossible scenes rather than construct equally exciting ones that are at least physically plausible? I think “Gone in 60 seconds” demonstrates emphatically that physically realistic scenes can still be exciting.

Another scene in this movie worth considering from the perspective of “Physics in Film” is the one where the police SUV gets knocked through the wall by the wrecking ball. It’s probably not realistic to think that the SUV would actually go through the wall (or that the cop involved wouldn’t have been more seriously hurt). Clearly that was a special “Hollywood” wall. Still, the scene was presented somewhat tongue-in-cheek. I mean consider the dialog following the scene:

G.R.A.B. special agent: “Are you alright?”
Patrol cop: “I think so.”
G.R.A.B. special agent: “Are you sure? ‘Cause you just went through a wall.”

Personally, I’m willing to forgive some lapses in physical reality, especially when they’re presented in a way that’s clearly not meant to be taken seriously, as in this scene.

This movie gets my vote for the worst movie physics of any of our feature films this semester; it even got ISMP’s vote as the #1 worst physics movie they’ve ever reviewed. To me, the bad physics is made even worse by the fact the movie takes itself way too seriously; there is very little humor; and I just don’t find myself connecting emotionally with any of the characters. So…

Assignment: The physics in this movie is so bad, your assignment is to try to keep track of all the physics blunders in the movie. You don’t have to work out all the details of why the physics is wrong, just give a brief description of each bit of bad physics you find in the movie. If you think you’ll need help, start by reading the ISMP review.

Please post your response on your blog by Monday, 29 Sep.

OK, there are plenty of things to criticize in this movie from a physics perspective, but at least they get off on the right foot. The opening sequence describes pretty well the event most scientists believe killed off the dinosaurs (they even have the asteroid hitting the Earth in the correct location). It’s also true that something like this will happen again someday. After that, things get pretty sketchy to put it mildly. Of course, there is the obligatory destruction of NY City, even though the likelihood of a few stray meteorites hitting one of the largest cities on Earth are remote to say the least (remember 70% of the Earth’s surface is covered with water, so most likely the meteoroids are going to hit an ocean). Still, I find this movie entertaining. To me it never appears to take itself too seriously and there are some very humorous scenes. I’ll admit to even getting caught up in the stories of heroism and personal sacrifice. But when it comes right down to it, NASA’s plan to save the world (as portrayed in the movie) is pure bunk; it just wouldn’t work as we’ll discover in class.

Assignment: Come up with a plan of your own to save the Earth; hopefully one that will work. Remember, this scenario (asteroid collision threatening all humanity) will happen sooner or later, so it would be good to have a working plan. You can adjust any of the following variables you like: how much time you have, how big the meteoroid is, what it is made of, how massive it is, how dense it is. You cannot, however, adjust the fact that on final approach to Earth any meteoroid will be traveling at roughly 25,000 mph (1.1×10⁴ m/s – the escape velocity at the surface of the Earth). So, tell me, how are you going to save mankind? If you’re stuck, I encourage you to brainstorm with other members of the class.

Please post your response to your blog by Monday, 22 Sep.

You could substitute just about any action movie here. Anything starring Arnold Schwarzenegger, Sylvester Stallone, Bruce Willis, Vin Diesel, etc. should do fine. They all have the same cliches and the same bad examples of physics. The two most widely violated physical principles in movies such as “Eraser” are the Law of Conservation of Momentum and the Law of Conservation of Energy. Mind you these are two of the most immutable laws of the universe for us mere mortals, yet somehow they don’t seem to apply in Hollywood action films. (You could add the Law of Conservation of Bullets to this list, too.) One of the most egregious examples of the violiation of the Law of Conservation of Momentum comes across this way: the hero can fire away on his/her gun with practically no recoil whatsoever, yet any bad guy hit by a bullet from said gun will be violently launched off their feet and into whatever structure happens to be behind them (often a glass wall or window). It just can’t happen that way!

Assignment: Analyze in detail any of the scenes where someone fires the rail gun and hits a victim, sending them flying. Your analysis should be centered around the application of the law of conservation of momentum. This will require calculating the momentum of each of the objects involved (shooter, victim, bullet, and gun) and then appropriately applying the law of conservation of momentum. Keep in mind that you may need to invoke conservation of momentum more than once. Also remember that objects can exchange momentum with other objects, provided the total momentum remains constant. If you have trouble, help each other out or write back to me for more input. As always, you should also feel free to comment on any other violations of the laws of physics that you happen to notice.

Please post your answers to your blog by Monday, 15 Sep.