Even at 90 years old, Stan Lee is still always ready to talk up Marvel superheroes.

Lee has never stopped evangelizing for the characters he co-created, and this year he's got yet another platform for it. He'll appear in the new three-part PBS documentary Superheroes: A Never-Ending Battle, which will premiere next Tuesday, and in it he took some time to talk about the approach he took to the fictional science behind many of Marvel's most iconic characters.

Though he describes himself as "the least scientific person you'll ever know," Lee at least tried to inject some kind of scientific logic into many of his characters, often using the philosophy "If it sounds good, I'll use it" (he cites the Hulk's gamma-ray origins as an example of this) to inject science into his stories while keeping things as research-free as possible.

"The whole trick is to make something seem as if you gave it a lot of thought and did a lot of research about this," Lee said. "I never had time for research, because were too many books that had to be written and we always had those deadlines to worry about."

One bit of Marvel "science" that Lee is particularly proud of is how Thor, the God of Thunder, manages to fly. Lee first points out that, over at DC Comics, they never gave Superman's flight any real explanation.

"When Superman flies, he has no visible means of locomotion...Not us. At Marvel, we're scientific," he said.

So, with Thor, Lee tried to devise some kind of logical reason why Thor could take flight, and found an answer in Thor's magical hammer, Mjolnir, which he uses as a launching device.

"So when the hammer goes shooting off into space, it takes him with it," Lee said. "That's how he flies! Incontrovertible scientific fact! And that's the difference between us and the competition."

Check out the full clip of Lee talking Marvel science above. If you're a big fan of his, you've likely heard some of it before, but it's always fun to watch him get excited about those characters.

(Via Boing Boing)