Many people don't know too much about angular momentum—and that's fine. But what about figure skaters? Whether they understand the concept of angular momentum doesn't matter but they use it in one of the all time classic skating moves. You've seen it before. The skater starts off in a standing position and spins about the vertical axis. After a few rotations, the skater pulls both arm in closer to the body and spins faster. In physics, we call this conservation of angular momentum.