Temple professors teach scientific principles through the lens of sci–fi and disaster films.
Story by Gary M. Kramer, SBM ´05
When it comes to action sequences, stunts, special effects and explosions in Hollywood movies—from volcanoes and earthquakes in the end–of–the–world film 2012 to nuclear explosions used to save the world from doomsday in Armageddon—most viewers wonder, "How did they do that?" But when Temple professors Leroy Dubeck and Jonathan Nyquist see science presented on the silver screen, such eye–popping scenes usually prompt them to ask, "Why did they do that?" instead.
Leroy Dubeck, professor of physics, and Jonathan Nyquist, Weeks Chair in Environmental Geology, respectively teach How Things Work: The Physics of Everyday Life and Disasters: Geology vs. Hollywood, two courses that explain scientific principles to nonmajors. Both classes debunk myths about everything from global warming and the greenhouse effect to natural disasters, such as earthquakes and tsunamis. Examples from action, sci–fi and disaster films illustrate scientific principles. For example, global warming may cause the polar ice caps to melt, but the idea that the event would flood Earth—as the premise of Waterworld suggests—just does not hold, well, water. "There´s not enough ice in the caps to cover all the land," says Nyquist, a geophysicist.
Even Yoda was Wrong
Dubeck, a longtime film buff, started using examples from films in his classes when he witnessed the popularity of Star Wars. However, even that sci–fi classic maligned a few principles of physics, such as telekinesis and the sounds of zooming, soaring ships as they plunge through space.
The law of conservation of energy proves that minds do not produce enough energy to move objects, Dubeck says."You cannot get energy from nothing—you can only transform energy from one form to another, or transfer it between objects." In Star Wars, Yoda moves a weighty spaceship with his mind, which violates the law of conservation of energy.
Likewise, there is no air in space to transmit sound. "Sound waves move in air by compressing air molecules," Dubeck confirms. "No molecules, no sound transmitted." Or, to cite the famous movie tagline for Alien, "In space, no one can hear you scream."
Getting a Kick Out of Terminator
Dubeck believes that showing films can captivate pupils. He uses cinema to make science "more relevant and interesting" to students who tend to remember scientific ideas more successfully with cinematic examples. He illustrates the law of conservation of momentum, which reads, "If one object exerts a force on a second, the second exerts an equal and opposite force on the first."
Dubeck applies this theory to gunplay in film. "If a gun pushes the bullet forward, the bullet pushes back on the gun, which is why recoil occurs. The more powder there is in the bullet, the more recoil. That´s reality." He points to the Terminator series, which relies heavily on gunfire.
"When you see the bullet hit someone, the impact knocks them down. But there is never recoil" Dubeck rejects the idea that the character of the larger–than–life Terminator is so big and strong, he could "resist" the force of the recoil. And when the Terminator is later knocked down by a gunshot, the human who shoots the robot does not experience recoil, either.
"In class, I compare that scene to a video of real guns—a Colt .38 and a sawed–off rifle," Dubeck says. "The kick is enormous—you can´t hold the gun! In the movies, the human saws it off and knocks the Terminator down and he doesn´t recoil at all."
Whether disasters on film are natural or manmade, moviegoers tend to retain expectations about such events. For example, Nyquist notes that when viewers watch a volcanic eruption, they assume that lava always moves at a flood–like speed. But different kinds of volcanoes produce lava of varying thicknesses.
Headed Right for Us
But Hollywood is not always wrong. Dubeck is impressed that the disaster film Deep Impact—about a comet heading toward Earth—is "actually quite accurate."
"A comet 7 miles wide, seen two years before impact, is plausible," he explains. "When [those chasing it] land on the comet, there is no gravity. Their attempt to destroy it with nukes fails—they just split it in two. The smaller comet piece falls into the sea and creates a tsunami."
The tsunami is caused because a comet the size of the one depicted in Deep Impact would release "energy equal to millions of Hiroshima–sized atomic bombs. That energy would be released, in part, as a pressure wave through the oceans," Dubeck notes.
Therefore, the energy would be great enough to displace sufficient amounts of water to generate giant tidal waves hundreds or thousands of feet high, as shown in the film.
But some moments in Deep Impact favor visual appeal over accuracy. "The surfaces of comets have very low reflectivity—like a black carpet," Dubeck says. "All you would see is black. Sunlight would not be reflected from the surface as seen in the film. You can´t see black in the movies, so they make it much lighter than it is. Viewers have to see it."
Professors Jonathan Nyquist (left) and Leroy Dubeck debate the scientific merits of sci–fi, disaster and action films. Photo credit: Ryan S. Brandenberg
In his class, Dubeck contrasts Deep Impact with the aforementioned Armageddon, a film he admonishes for its "laughable" physics. Yet he uses Armageddon to assign research projects, such as plotting the trajectory of a near–Earth asteroid and calculating its value and probability employing the Torino impact hazard scale. (The scale is used by NASA to predict the possible impact threat of asteroids and comets.)
"It would take the simultaneous detonation of 10,000 atomic bombs to destroy the asteroid in Armageddon," he says. "Often, movies will take five minutes of screen time to solve a scientific problem that would take 500 years in real time."
Dubeck aims to teach his students the laws of physics so they can better understand the world in which they live. "I want them to learn more about the universe and the way things work, and look critically at the information they get from mass media," he says. "Most of them get their information from media, not scientific papers. If they learn to be more critical, that will be with them for the rest of their lives."
Earthquakes Are Predictable
Nyquist also wants his students to keep reading about the topics he presents in class, so they can "read between the lines" and be educated about the next earthquake. Nyquist says that one fallacy students often believe is that during earthquakes, the Earth breaks apart and sucks the landscape and its inhabitants into fault lines. "Earthquake faults don’t do that," he notes. "That´s a classic Hollywood cliché."
"Part of California is on a separate plate," he explains. "It is sliding past the North American plate, but it is not going to fall into the ocean. It´s on continental crust, which is buoyant and floats on the mantle material below it. When two continents collide, neither one of them sinks; instead, the result is something like the Himalayas. California is not going to get sucked underneath."
Nyquist uses those geological principles to get students thinking about quakes and, more importantly, how to prepare for and even predict them. "Earthquakes kick out waves. ´P waves´—primary waves—come first, but don´t do much damage. The ´S waves,´ or secondary waves, are next; they shake things up. The P wave travels faster. When the P wave hits, you know the S wave is coming."
In Hollywood films, earthquakes almost always happen without warning, Nyquist notes. He is amazed at how sloppy Hollywood is about details. In the film The Core—about a nuclear bomb deployed by a team of scientists, government officials and military officers—a ship tunnels through solid rock.
"The filmmakers wanted the ship to have a window," Nyquist recalls, positing that viewers needed to see what the ship´s crew was seeing and doing. "But the whole ship would break under the geologic pressure near the core." A window would melt, so the writers "solved" the problem of showing the action by using an invented metal called "unobtainium" that could withstand the heat and pressure.
While writers and directors sometimes come up with interesting solutions to scientific problems, sometimes they simply take chances. Consider how disaster movies depict volcanoes. Nyquist expresses his exasperation: "They take everything a volcano can do and throw it into one disaster."
He goes on to explain why this is wrong. "Volcanoes come in different types. Stratovolcanoes, like Mount St. Helens, are found along coastlines. They are more explosive than shield volcanoes, which are common in Hawaii and erupt almost continuously. Shield volcanoes don´t erupt the way Mount St. Helens erupts. Hawaiian lava is less viscous, so it flows more easily, which reduces the pressure buildup and chance of an explosive eruption. Mount St. Helens has high–viscosity magma, so its lava does not flow easily. When Hollywood creates a volcano, it does all those things."
He continues, shaking his head. "Look at Dante´s Peak, about a dormant volcano that wreaks havoc: It´s an explosive volcano and it has lava flows. Audiences expect that. If there are no lava flows, it doesn´t seem right."
Scenes like these might endanger Nyquist´s—and his colleague Dubeck´s—suspension of disbelief, but he certainly understands why directors do it. "You want a lot of special effects, so you have to draw the action out. These movies are rollercoaster rides. You go for the thrill, and not for the science. And, it´s easy to root for the heroes when the bad guy is nature."
Gary M. Kramer, SBM ´05, is a Philadelphia–based freelance writer whose work appears regularly in numerous magazines and journals. He also is publicity manager for Temple University Press.