A top physicist unpacks the surprising real-life science behind the shrinking superhero – and that Thanos fan theory.

By Stephen Kelly

Published: Friday, 17 February 2023 at 12:00 am


It’s a tiny bird! It’s a miniature plane! It’s Ant-Man! Yes, the bite-sized superhero is back in the new film Ant-Man And The Wasp: Quantumania, where he is set to shrink to the size of particles.

The idea of shrinking people is a popular one in science fiction – just take Fantastic Voyage or Honey, I Shrunk The Kids – but is it feasible in reality?

James Kakalios, a physics professor at the University of Minnesota, and author of The Physics Of Superheroes, is not convinced.

“My first thought is: I wish. My second thought is: no,” he says. “The size of atoms is determined by quantum mechanics and electrostatics, which involve a set of fundamental constants and fundamental interactions. Constants are constant; they don’t change.

“Without being able to change those constants, and without being able to change the nature of the electrostatic interaction, there’s no way to reduce the size of an atom.”

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Well, that’s not right, because Dr Hank Pym – the original Ant-Man, played by Michael Douglas in the films – has not only figured out how to shrink Scott Lang (Paul Rudd) to the size of an ant, but also how to retain his full-sized strength while remaining lightweight.

“If you have the mass of an ant, you are not knocking down a bad guy,” says Kakalios, who theorises that Pym would have had to figure out a way for Lang to change his mass at will during a fight.

“When he sits on an ant, he doesn’t smush it in the same way I would,” he says.

“This makes me think that Pym can manipulate the Higgs field, the thing that gives all matter the mass and inertia that it has. So, only two impossible things! What a genius!”

Without such an innovation, Lang would struggle to punch his way out of a paper bag. But if Pym had indeed figured out how to increase a tiny Lang’s mass at the same time as he is throwing a punch, it could make him deadly.

“He would have to be careful,” says Kakalios. “You could punch a small hole in their neck and pierce the jugular vein. It would be like being struck with a bullet.”

Speaking of which, there is a popular fan theory floating around the internet that Ant-Man is perhaps the most powerful Avenger of all; that it is he, and only he, that has the power to kill Thanos and stop all the events of Infinity War and Endgame from happening.

All he would have to do is to shrink down to the size of an ant, climb inside Thanos from a certain orifice, and then blow up to full-size, theoretically destroying Thanos in the process.

What does James Kakalios, a distinguished professor, think of that theory?

“Oh god,” he says. “You’re talking about Thanos’ butt!” Yep, that’s exactly what we’re talking about.

“What I will say is that Thanos is very strong, possibly inside and out. Say that Scott, initially the size of an ant, expands in a room that is surrounded by miles thick concrete walls in all directions – all he’s going to do is crack his own skull.”

So what you’re saying, James, is that Thanos could have bowels of steel?

“You know,” he says, “I’d say this is one case where I’m willing to take my science hat off and say: I don’t need experimental verification.”

About our expert

James Kakalios is a professor of physics and astronomy at the University of Minnesota. He is the author of The Physics of Superheroes and The Amazing Story of Quantum Mechanics. In 2009, He won a regional Emmy Award for his short film The Science of Watchmen.

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