Jerry Lu’s technology demystifies winter sports by tracking athletes’ speed, jumps, and rotations. Part of a figure skater’s job is to make their routine look as effortless and graceful as possible, as if they’re floating on ice and soaring into the air through sheer force of will. In reality, they’re often launching themselves multiple feet into the air with what amounts to sand bags on their feet; generating hundreds of pounds of centripetal force through rotations; and landing on a blade that’s just 3/16 of an inch wide.