Sometimes you want to just kick back with a cool beverage of choice, and you know...? Do something crazy with your iPad!! Maybe something radical like: observe the conservation of angular momentum applied to a smooth body in motion as it turns ever more rapidly around it's center of mass. Huh, you say?!.. Ever see a skater speed up in a spin just by pulling in her arms? That's an application of exactly what I'm talking about, and you can learn a lot more about these interesting physics principles using the HyperPhysics app!