"Superman Returns" Science: Decoding the Movie Hero's Powers

Richard A. Lovett
for National Geographic News
June 23, 2006
This month Superman Returns opens in U.S. movie theaters, and the world's oldest comic book superhero turns 68—stronger, more resilient, and presumably more super than ever.

Most of us would view the Man of Steel as a purely fantastic creation. After all, he has x-ray vision, leaps tall buildings in a single bound, blows icy winds, is impervious to bullets—the list goes on.

But while a lot of the action in Superman Returns will undoubtedly be impossible, much about the Last Son of Krypton is anchored in real science.

"Comic books get their science right more often than one would expect," said James Kakalios, a University of Minnesota physics professor.

"Of course, the hero's superpowers violate the laws of nature as we understand them, but once you grant a one-time 'miracle exception,' what follows is often surprisingly consistent with known physics," said Kakalios, who authored The Physics of Superheroes.

(Related photos and news: animals with Superman "powers".)

Consider Superman's strength.

As any fan knows, the original explanation for Big Blue's power and skyscraping leaps was gravity. He comes, the story goes, from the destroyed planet Krypton, where gravity was stronger than it is on Earth.

Under this theory, Superman on our planet is like a human astronaut bounding around on the moon, only more so. The same applies to any of his other feats of strength, Kakalios says.

The biggest problem with this idea, says Michael Dennin, a physics professor at the University of California, Irvine, is that he can also walk normally—rather than bounding around like an astronaut on the moon.

Another problem is that he remains powerful no matter how long he stays on Earth. Because weightlessness forces people to use their muscles less, "astronauts get weaker with time," Dennin says.

You Will Believe a Man Can Fly?

Superman's ability to fly is even more problematic.

"You need a source of thrust and lift," Dennin said. "There's no way around that."

"In the early [comic books] he could jump and be an unguided missile," the University of Minnesota's Kakalios said.

"But he's [now] able to change direction at will, so he's gained some ability over gravity that would baffle scientists."

Not that this stops the Man of Tomorrow's fans from speculating.

Hal Sparks, an actor and comic book fan, holds forth in The Science of Superman, a National Geographic Channel television special premiering in the U.S. on Thursday, June 29, at 9 p.m. ET/PT. (National Geographic News is part of the National Geographic Society, which is part owner of the National Geographic Channel.)

"This is my theory: [His] flying is based on the magnetic content of his body and the Earth's polarity, so he can push himself away and pull himself toward it," Sparks said.

Science writer Mark Wolverton, another guest on the show, suggests that Superman might be able to generate hypothetical subatomic particles called gravitons.

"If Superman has a way of generating gravitons … I would say he would be flying by essentially riding the waves of gravity that are in his immediate environment."

Similarly, magnetic fields have been used to levitate trains. And in the laboratory, frogs have been elevated when a very strong magnetic field is applied to the water in their bodies. (Watch video of a levitating frog.)

But it's hard to see how Superman could draw enough power from the Earth's magnetic field.

As for gravitons, Minnesota's Kakalios points out that they're particles that haven't yet been observed and that repulsion would presumably require the even-more-theoretical antigravitons.

"If you're going to make up particles, you might as well just make up that he flies," Kakalios said.

(Related: "The Science of Superheroes: Beyond The Incredibles" [November 12, 2004].)

Could Superman's other superpowers be easier to explain?


"Maybe he 'superheals,'" Kakalios suggests. Perhaps "it looks like he's invulnerable because no matter what harmed him, his cells instantly regenerate"—a sort of supercharged version of the signature power of the X-men comic book and movie character Wolverine.

X-Ray Vision

Strictly speaking, this power would require Superman's eyes to somehow emit x-rays, which would penetrate what he's looking at and then bounce back at him.

But, the University of California's Dennin says, x-rays don't bounce. Even if they did, that doesn't explain how his vision allows him to "peel away" obstructing layers one at a time, like a medical CT scanner.

For this reason, Frank Frisch, a biology professor from Chapman University, will present an entirely new theory in The Science of Superman: Maybe Superman doesn't really have x-ray vision.

Instead, he may use sound waves for a sonarlike mapping power that doesn't need x-rays—much as doctors use sound to create sonograms of unborn babies.

Heat Vision

To melt things with laserlike beams from his eyes, Superman would need "a very large power source," Dennin says—which brings us to …


Heat vision isn't the only superskill that requires a lot of power. One explanation is that Superman converts light from our yellow sun—which is presumably more intense than the red sun of Krypton—into energy that he then stores like a humanoid battery.

Unfortunately, our sunlight isn't really all that different from the light of other stars.

Todd Barber, a propulsion engineer for NASA's Jet Propulsion Laboratory in Pasadena, California, has calculated the amount of energy needed for some of Superman's feats.

It turns out that, even assuming he goes into space, where the sunlight is more intense, he'd have to spend a lot of time recharging his batteries between superdeeds.


The Man of Steel's superacute hearing would seem to be one of his more mundane talents. But it's actually rather inexplicable, says Minnesota's Kakalios. Not because it's so acute, but because there have been instances where he's heard the crack of a gun and flown all the way across his home city of Metropolis in time to stop the speeding bullet.

The problem is that—the speed of sound being what it is—by the time the noise got to him, the bullet would have long since found its mark.


Perhaps a more believable talent is the ability to blow very, very hard—hard enough to push away thunderstorms or freeze nearby objects.

Assuming his superlungs can drastically compress air, the freezing effect might actually work, Barber says. That's because gas cools as it expands—an effect that Superman facilitates by pursing his lips so that the air blasts out like rocket exhaust through a nozzle.

Survival in Space

The same superbreath may be what allows him to survive in space without a space suit. To blow so hard, he would have to be able to inhale large quantities of air. And if he can do that, he may be able to hold his breath and "dive" into space for long periods of time.

Bottom line: For his powers to work, Superman would require more than one "miracle exemption." But after 68 years, perhaps he's earned them.

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