Someone just broke the entire Marvel universe with basic chemistry! Oxygen molecules (Oโ) are what we breathe, but individual oxygen atoms are much smaller! The diameter of an oxygen atom is about 0.14 nanometers, while Ant-Man supposedly shrinks to subatomic size (smaller than atoms). If he's smaller than oxygen atoms, he couldn't possibly interact with oxygen molecules to breathe! This is the perfect "wait a minute..." moment that science nerds live for. Next time you're watching Ant-Man, you can be that person who ruins the movie with science facts! ๐ Though honestly, the Pym Particle explanation probably covers this somehow... superhero physics always finds a way!