Spider-Man has always been tied up with the world of science. After all, it is a bite from a radioactive spider—developed, we learn, in the latest chapter of the Hollywood franchise by Peter Parker’s own scientist father—that would transform the teenager into a human arachnid. The new Amazing Spider-Man movies abound with mad scientists whose experiments go awry, from Harry Osborne’s ill-fated DNA-mixing transformation into the Green Goblin to Curt Connor’s similar metamorphosis into The Lizard.

In The Amazing Spider-Man 2, Electro is the latest human to fall prey to the dark side of science. Jamie Foxx plays nerdy electrical engineer Max Dillon, who accidentally electrocutes himself, falls into a vat of electric eels, and emerges as a powerhouse bad-guy. While the high-voltage character stretches the limits of scientific reality, Science and Film spoke with Professor Richard Sonnenfeld, a professor of physics at the New Mexico Institute of Mining and Technology and a research scientist at the Langmuir Laboratory for Atmospheric Research, about human batteries and capacitors, the power of lightning, and how to stop a 10-million-volt super-villain from destroying your city.

Sloan Science and Film: The city of New York is powered by an electromagnetic power grid. Is that effective for the future powering of cities?

Richard Sonnenfeld: One of the problems in movies often is that they use the right words, but they don’t know what they mean. The power grid is already electromagnetic. Electricity and magnetism are closely tied together. The power grid is electrical, and electric currents can make magnetic fields. Unless they’re implying that there is some electromagnetic source of power. But that doesn’t make sense, because they have to convert some other energy source—sun, fission, fossil fuels—into electricity.

SSF: Well, this gets into how Electro is formed. In the world of Spider-Man, we see biogenetic engineering with animals—hence, “spider-man”—and in the new film, scientists have harvested electric eels for the power grid, and they’re in these enormous vats. The guy who turns into Electro falls into one.

RS: That’s cool. When I was thinking of Electro and how unrealistic he was, I thought about electric eels, and thought, “It can be done.” If he could pick up some of the electrical producing cells of the eels (called electrocytes), that would be a good thing. If we wanted to splice electric eel power cells into him, I could go for that.

SSF: I realize you’re not a biologist, but how would that work?

RS: My understanding is that all of our cells operate electrically; they are pumping ions in and out all the time and changing charges, and nerve cells absolutely work on electrochemistry. My sense is that if you can generate half a volt out of a nerve cell, and you could stack up a bunch of them, in theory, you could get a reasonable voltage. Electric eels generate about 1/6th of a volt per electrocyte, but stack up thousands of them to generate typically 600 volts. But they do not shoot lighting bolts, because their voltage isn’t high enough.

SSF: So can you explain if Electro were to pull electric eel cells into his body, how would this make him an electrical powerhouse?

RS: So rather than a capacitor, he’s more like a battery. He digests his hamburger; he feeds his cells, and among the things the cells will do with chemical energy is create electricity. So he would be feeding his electrical cells with food, and when he needs to produce a charge, he would generate a charge electro-chemically. It makes a lot more sense than if he were a living capacitor.

SSF: Why is that?

RS: A capacitor stores charge and stores energy. I’ve worked with 100,000 volt capacitors. Depending on how it’s designed, you can make nice arcs. But the problem with a conventional capacitor is that you have bunch of conducting plates with an insulator in between them, so that’s a problem with a human body. Because it’s full of salt water, it’d short itself out all the time. If it did hold a charge, there are all sorts of problems. If he has a million volts moving from one side of the body to another, why wouldn’t he electrocute himself? If he’s shooting sparks out of his fingers, that means that his fingers are going to a much higher voltage than the rest of the world, so how does he do that? The electric eel does it by doing some chemistry on the fly, and I guess that’s my best theory for him. But he’s really a battery, not a capacitor. By the way, there is some evidence that electric eels do in fact shock themselves, but that they are more resistant to the effect than their prey is.

SSF: So let’s talk about arcs and lightning, because that is what it looks like Electro is shooting out from his hands. Can you talk about the power that we are dealing with? Electro is able to stop trucks and knock down buildings with his arcs, but how much power do lightning bolts actually have?

RS: First, people always confuse power and energy. Energy is measured in joules. Power is measured in watts. If you go with the biggest numbers, I’d say 10 million volts up to 100,000 amps, which is a lot. Now how much energy is in a lightning flash? It is a surprisingly small amount: the peak power of a lightning flash is a terawatt. But you get it for, at most, a millisecond. So for energy, you get a gigajoule. That sounds like a lot, except 3.6 megajoules is a kilowatt-hour. So basically you’re best lightning flash is 300 kilowatt hours. So if you were to use lightning as an alternative energy source, one lightning flash is worth $30.
So what can you do with a gigajoule—lightning will punch holes in metal objects, in some circumstances. But if you look at lightning rods that have been a hit, it will have a little divot in it. So that’s not really exciting for Hollywood. In terms of knocking over a truck, no. Lightning does blow up trees, but it does it by superheating the water underneath the bark and the hot water blows off the bark. People who are hit by lightning, their clothes get blown off, but probably from vaporizing the sweat on their skin. If you’re soaking wet, you might survive, because most of the current would happen on the surface. You can certainly kill someone with a lightning flash. But I don’t know about knocking over trucks.

SSF: So how much lightning would it take to do real damage?

RS: This whole absorbing and re-transmitting power, I have no idea how he does it. Batteries and capacitors do similar things; they both store energy; they both have voltage; you can make high voltage batteries. But since capacitors are purely electrical, they can release their current and store their current very quickly. If you want to make a lightning bolt, you want a capacitor, but lightning flashes are fast, the peak current is a 1000th of a second, or 10,000th of a second, and once you get an electrical arc you’re done. But Hollywood wants lightning bolts to last a couple seconds, so that’s more of a battery. But batteries aren’t good at producing high currents. Electro is an engineering compromise. Everyone would love something that can produce high currents like a capacitor, and produce them for a long time like a battery, but we don’t know how to do either of those things, and certainly not in a human body.

SSF: [SPOILER ALERT!] This gets to this question of how they defeat him. It appears that Spider-Man magnetizes his web-shooters and over-charges Electro.

RS: Many people don’t know the difference between magnetism and electricity. But I don’t see how magnetized web-shooters would short-out an electrical guy. I thought they would dump him in a bucket of salt water, which seems like a better idea to me. Since he produces such a high current, throw him in the ocean; that’s how I would defeat him.

SSF: If he is a more like a battery, how would they overcharge him?

RS: Every device (capacitors or batteries) does have a maximum voltage rating. On YouTube, you can see people making cheap capacitors, by taking sheets of aluminum foil with wax paper between them. And in every capacitor, if you put too much voltage on it, it will short out; if you really push it, you can blow holes in the insulator—or the wax paper, in my YouTube example—and it will short out. If he has some internal non-conducting membranes to separate his charges, if you over-volted him, you could blow holes in his membrane, and he wouldn’t be able to hold a charge anymore. He probably is 10 million volts himself, so you’d need 100 million volts to short him out. I’d short him with natural lightning. I’d take him up in the mountains where I work and with one of the lightning triggering rockets we use at Langmuir lab.

SSF: In terms of real lightning research, can you tell me what is going on in the field right now that’s exciting to you?

RS: We have an understanding of lightning that is much better now. Almost every lightning flash that reaches the ground in the continental U.S. is measured and digitally archived and available on the web, and that’s extremely helpful for public safety, and some of these instruments we have developed are diagnostic, which can, for example, predict tornados slightly in advance. Because lightning goes up in high altitudes right before a tornado. So there’s some nice forecasting, or what’s called nowcasting research, coming out of our studies.