Motion sensors have a long history dating back to when early humans used movements of stars and crops to determine seasons. They were first widely used in World War II in mines and claymores to detect enemy movement. Technologically, motion sensors work by emitting waves that bounce off objects and are detected, with the information used to trigger a device. Today they have many applications in security, lighting, tracking, and more, bringing both benefits like convenience and disadvantages like easy accidental triggering. Motion sensors continue advancing, with potential uses like tracking performance through sensors embedded in clothing.

1. Motion Sensors Casey Corbin TED 111 Dr. Kallis