The Curvature of a Green Fly Line

i'm going to ask these questions where i have a physical need to or text for it. I know if i put a bead head nymph six inches below the surface that's dragging through water that moves at a certain speed, i know exactly how far down in the water that's going to go. There's this other element of math iis basely fancy calculus. It's called differential equations. And so differential equations lets you do more interesting things. So imagine like a, everything is it's like an unbalanced seesaw. And then you havea d. If you were a master at tuning things with math, you could do what's called control systems using differential equations.