OK. Weird question. What is a technology that couldn't exist without calculus? Like, a specific engineered artifact -- a bridge, a segway, a waterjet cutter -- that couldn't have come into being without calculus. Not necessarily a hard question, just something I'm pondering for fun. Trying to get a better grasp on the real value of things like mathematics. (One thought I'm having is that if you were intuitive enough, you could engineer anything without explicit math/science. Say, if you started building small bridges as a kid, and by the time you were an adult you had gotten a good "feel" for it, and could do it without any book learning. So I'm thinking about whether math is truly necessary.) But... that's kinda off the deep end :D. Let's keep it as "What is a technology that couldn't exist without calculus?"