Mark Ruffalo went on The Colbert Report to talk about fracking, and Stephen yelled at him — even though he acknowledged later that it’s probably a bad idea to yell at the Hulk.

Favorite part: the extended attempts to interrupt each other, followed by the extended attempts to defer to each other, followed by Colbert’s irrefutable assertion that “you can’t run your car on the sun, it is huge and super-hot.”