Spoiler alert if you haven’t seen Captain America: Civil War yet. But go see it already, it’s great.

What was the best part of Captain America: Civil War? Spider-Man? The big Baron Zemo twist? For me, it was probably the airport battle where we got to see all the superpowers introduced Age the Ultron come into play. The biggest (literally) among these was Ant-Man‘s new “trick.”

In my latest Because Science, I’m breaking down the physics of Scott Lang’s long-awaited transformation into “Giant Man.” Turning into a massive, AT-AT-like enemy is pretty complicated, so for this episode I enlisted the help of quantum physicist Spyridon Michalakis, who consulted on the Ant-Man movie.

Not too long ago, we talked to Dr. Michalakis about how Ant-Man’s suit could work, but you can’t just reverse that process and get Giant-Man. Instead, Lang vis-à-vis Pym would have to use something like special neutrinos—ghostly particles that pass through pretty much everything without interacting with other particles. If the suit could produce those particles en masse, they would eventually interact with all the atoms in Lang’s body, transforming protons into neutrons. This sudden bulge of neutrons would push electrons out from the center of the atoms, increasing the size of the atoms and thus the object.

But it’s not so straightforward. Lang’s transformation might kill him, or produce another Hulk…

Check out my last video on whether Spider-Man could swing on actual spider silk, subscribe to this playlist to stay current with the show, buy a Because Science shirt (you know why), and follow me on Twitter to give me a suggestion for the next episode!