Superhero science

Fans of the "Watchmen" graphic-novel series are scrutinizing the film for its faithfulness to original characters and story lines. James Kakalios is looking for something else -- whether the film gets its science right.

"When I saw 'Iron Man,' I was one of very few people who got excited about the soldering," he said. "Robert Downey Jr. was using the same soldering tool I have in my lab to build his armor, and he was holding it correctly."

Kakalios, a physics professor at the University of Minnesota, was an adviser on the "Watchmen" film, which opened last weekend. He was referred after the National Academy of Sciences got a call from the production staff requesting a consult. No one was more suited to the job than Kakalios, who wrote "The Physics of Superheroes." A lifelong comic-book fan, he even used them as stress relief while working on his dissertation. Then he hit on a way to get students engaged in physics -- using science to explain the powers of comic-book characters.

"I've covered everything from Isaac Newton to the transistor with comics," he said. "With the superpowers, we grant each character a one-time miracle exemption from the laws of nature, because of course what they do is physically impossible."

Take Dr. Manhattan of "Watchmen," a physicist who has a nasty lab accident that turns him into a blue-hued superhero able to instantly move himself great distances, such as from Earth to Mars, via quantum mechanics. Listening to Kakalios explain that is enough to strain an average brain:

"Matter can sometimes leak through barriers and be where it's not supposed to be. When light is reflected off a barrier, electric fields can leak through and propagate.

"Even electrons do this; you can have a metal separated from another metal by a space vacuum, and there's a small probability one will leak to the other. This is no less weird for being true.

"This seems like strange mumbo-jumbo, but this is what's involved in making your cell phone work. Dr. Manhattan is extending his wave out to extreme locations."

Then there's the matter of why Dr. Manhattan is blue: "Cerenkov radiation," Kakalios said. "When a charged particle, such as an electron, moves through water faster than light can in water, it creates the analog of an electromagnetic sonic boom. The speeding electron generates light in the blue/ultraviolet region of the spectrum, which is the source of the blue glow one sees from nuclear-reactor piles at the bottom of pools of water."

Does your head hurt yet?

"Presumably, a side effect of having to rebuild himself atom by atom is that Dr. Manhattan is continually leaking high-energy electrons, emitting a blue glow via Cerenkov radiation," Kakalios said. "Not strictly true, but a hand-waving explanation. And see, I just squeezed in a lesson. Sneaky ninja physics teaching!"

As for the movie's flying Owl Ship: "This is why we don't have flying cars," he said. "It would take an incredible amount of energy to levitate an SUV."

Kakalios spent a day on the set in Vancouver, and told the filmmakers that a physicists' lab is very messy.

"We're always trying to solve the latest problem; we don't care whether it's pretty or not," he said. "But the movie used the original 'Watchmen' series as its ultimate visual guide. You couldn't swing a cat without hitting a copy. Better that they annoy one physics professor from Minnesota than a million rabid fans."

Kakalios also advised actor Billy Crudup, who plays Dr. Manhattan.

"Billy actually knows quite a bit of science," he said. "He asked me mostly about the psychology of being a physicist. The more Dr. Manhattan feels alienated, the more he throws himself into his work. That is very typical."

Kakalios gives the "Watchmen" crew high marks for trying so hard to get the science right.

"Hollywood is trying more and more to create a believable artificial reality," he said. "They're asking audiences to buy into some ridiculous premises, so the more serious and straight they are with the details, the more you'll be able to suspend disbelief."

Kristin Tillotson • 612-673-7046