Rate of change is this mathematics known as Calculus. ... Now I hope you understand this, because I've never been able to make head nor tail of it. It must be some sort of a Black Magic operation, started out by the Luce cult - some immoral people who are operating up in New York City, Rockefeller Plaza - been thoroughly condemned by the whole society. Anyway, their rate-of-change theory - I've never seen any use for that mathematics, by the way - I love that mathematics, because it - I asked an engineer, one time, who was in his 6th year of engineering, if he'd ever used Calculus, and he told me yeah, once, once I did, he said. When did you use it? And he said I used it once. Let me see, what did you use it on? Oh yeah. Something on the rate-of-change of steam particles in boilers. And then we went out and tested it and found the answer was wrong.