The Hulk: Fact vs. Fiction

Stefan Lovgren
for National Geographic News
July 2, 2003
A few years ago, the filmmakers behind The Hulk began surfing the Internet in search of some real-life science to update the classic comic book story about a shy scientist who transforms into a raging beast.

On the Web site for the Lawrence Berkeley National Laboratory, they found what they were looking for: the Gamma Sphere, a super-advanced spectrometer designed to detect gamma rays, extremely powerful radiation.

With its vivid colors and angled metal supports, the hulking machine looked the perfect part. Hollywood technology wizards quickly built their own replica of the Gamma Sphere. In the movie, the monster within Bruce Banner is unleashed after the scientist is hit with gamma rays during an experiment.

"The Gamma Sphere in the movie is very realistic and looks the same as the real one," said I-Yang Lee, who heads Berkeley's nuclear physics program. "But there's one big difference. Our Gamma Sphere doesn't emit radiation, it detects it."

OK, so there may not be a real gamma ray machine that occasionally zaps poor scientists and turns them into giant green monsters. Hollywood can still twist the truth to fit or embellish a story.

But the science behind Hollywood movies is turning increasingly sophisticated. As audiences grow more science savvy—there are even Web sites rating movies based on the plausibility of movie physics—filmmakers strive to make their movies as scientifically realistic as possible.

Mutated DNA

In The Hulk, Banner's father, David, an Army scientist, gets a little carried away with an experiment to boost his immune system by mutating his DNA. He survives, but passes on the mutated DNA to his son, Bruce.

When Bruce, who grows up to be a scientist, is hit with a massive dose of gamma radiation—fatal to anyone with a normal genetic makeup—he doesn't die. Instead, the accident triggers the mutated DNA and unleashes the Hulk within Bruce.

To ensure that the story was based on accurate science, Universal Pictures hired a science consultant, John Underkoffler, to work on the movie.

"The first thing they wanted me to come up with was an explanation for the research that the scientists in the film were pursuing, which would then lead to the accident that creates the Hulk," said Underkoffler.

"[The director] also wanted all the background, the techniques and gestures, from how to hold a beaker to the more theoretical, to be as realistic as possible."

While the mutations that the Hulk goes through are clearly in the comic book realm, doctors in real life are able to introduce genes into the body to repair damage on a sub-cellular level.

The catalyst that triggers the younger Banner's transformation may not be that far-fetched either. Studies have documented the amazing effects of the addition of a simple dose of adrenaline into the bloodstream of animals and humans.

Adrenaline boosts has been known to provide brief episodes of superhuman strength, like the time when a 123-pound (56-kilogram) Florida mom reportedly lifted a 3,000-pound (1,350-kilogram) vehicle off her trapped child.

Teaching Comic Book Science

A few books, such as The Science of Superheroes by Lois H. Gresh and Robert Weinberg, test the science depicted in comic books. Some university professors, like James Kakalios of the University of Minnesota in Minneapolis, even believe the fantastic feats of superheroes are useful for teaching physics.

Kakalios teaches a physics course nicknamed, "Everything I know of science, I learnt from reading comic books," where final exam projects have posed such questions as: "If you, like the comic book hero the Flash, were to run around the world in 80 seconds, how much would you have to eat in order to have the calories?" (Answer: everything in The Joy of Cooking—26 times).

"Students are so busy enjoying their superhero ice cream sundae that they don't notice that I'm sneakily getting them to lower their guard and eat their spinach at the same time," Kakalios told an American Physical Society meeting in Austin, Texas, this spring.

Insultingly Stupid Movie Physics

Then there are the self-proclaimed "techno-nerds," who dissect and criticize every technical or scientific detail in movies. One Web site, "Insultingly Stupid Movie Physics," even reviews movies based on their scientific merit.

Titanic, Pearl Harbor and the first Terminator movie all receive a "PGP" rating for "pretty good physics." Meanwhile, Star Wars: The Phantom Menace, Armageddon, and AI: Artificial Intelligence were slapped with "XP" ratings for containing "physics from an unknown universe." Tom Rogers, an engineer who runs the Web site, has not seen The Hulk, but based on the trailers and on-line reviews his impression is that its physics are "pure comic book silliness."

"In theory, a rapid metamorphosis process is possible, but not on the level depicted in the movie," he said.

Rogers believes that, short term, the Hulk's strength could increase by as much as ten times, and the perceived size could increase by, say, 25 percent.

This could be done by some combination of inhaling and changing to a more upright posture.

"However, it couldn't be done without decreasing density," he said. "The Hulk appears to be at least twice his normal human height when he first appears.

"This would mean an increase in volume of eight times and an increase in weight of eight times. Where would all this mass come from?"

Meanwhile, I-Yang Lee, the nuclear scientist at the Berkeley lab, saw the movie. He agrees that it's not realistic, but says he still liked it.

"At least it had a plot," he said. "Science fiction movies don't always have that."

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