Just a few miles down the highway from Open Culture’s gleaming headquarters you will find Los Gatos High School, where Dan Burns, an AP Physics Teacher, has figured out a simple but clever way to visualize gravity, as it was explained by Einstein’s 1915 General Theory of Relativity. Get $20 of spandex, some marbles, a couple of weights, and you’re all good to go. Using these readily-available objects, you can demonstrate how matter warps space-time, how objects gravitate towards one another, and why objects orbit in the way they do. My favorite part comes at the 2:15 mark, where Burns demonstrates the answer to a question you’ve maybe pondered before: why do all planets happen to orbit the sun moving in a clockwise (rather than counter-clockwise) fashion? Now you can find out why.