Equations are all well and good when you have things like "Let x = something" "Let b = the spin" "Let y = the weight" ect... But if you wanted to really do your own experiement at home. I have a penny on my desk, I'm sure you have all done it before but if I hold it on it's edge and then spin it, I want to measure with precision the rate at which the angle of the penny changes. I also want to measure the rate at which the spin slows down per second. How would someone, without any kind of computer or anything prove anything like this? The point I'm getting at is newton used calculus to show the orbits of planets... no technology existed then that could possibly help him.