But could someone build a particle accelerator in his home (or tiny lab), like Tony Stark does? The answer might surprise you. "People have," Satogata says. "As a matter of fact, occasionally you get a really smart teenager building one." (Fun fact: The first particle accelerator, called a cyclotron, was 5 inches in diameter—small enough to hold.) You'd need a beam tube with a large vacuum, charged particles, magnets to bend the beam, and radio frequency oscillators, or RF cavities, to accelerate the particles. "For the types of things he's doing, he'd probably need much bigger magnets—I didn't even see any magnets," Satogata says. "So that's a little bit unrealistic unless he's got really, really strong magnets." There's nothing to accelerate the particles, either, but Satogata says the RF cavities could be offscreen.