There's actually a theoretically reasonable explaination behind the Hulk: be kind to all your biologist friends.
Separating fact from fan fiction in the world of comic books is an herculean task, especially when faced with thousands of inextricably tangled storylines spread throughout multiple multiiverses. Thankfully, Stanford biologist Sebastian Alvarado is on the case! Explaining the scientific possibilities some of our favorite costumed crusaders, thus far, Alverado's taken the physical transformations of Captain America and The Incredible Hulk down to the molecular level. We're hoping that if he tries to take Bruce Wayne or Tony Stark on next, he'll bring in an Economics major— we wouldn't mind some super-heroic stock market tips, either!
For more of Stanford's educational forays into pop culture, visit its YouTube channel.