I never really felt like I understood Calculus until I watched the Mechanical Universe on PBS. Here's an example, demonstrating how Kepler's Second Law is an e

I never really felt like I understood Calculus until I watched the Mechanical Universe on PBS. Here's an example, demonstrating how Kepler's Second Law is an expression of the conservation of angular momentum. https://www.youtube.com/watch?v=0tSmY4fn5xY#t=7m50s https://www.youtube.com/watch?v=0tSmY4fn5xY#t=7m50s