"Hey, no hard questions right out the gate." Tony ran his fingers over the deck in his hand, swaying his head this way and that as he considered her question.

"I like differential equations. I use them a lot for making my armor." Tony tapped the broad side of the card against his thigh. "Reality, nature, it's always changing. Differential equations help you break mother nature's laws into a language we can understand. And when we understand it, we can adapt."