Rattleback (Celt)

Description
A carved piece of wood, known as a rattleback, reverses its direction of spin when spun in a particular way. This behavior demonstrates the principles of angular momentum and torque. The asymmetric shape and mass distribution cause an interaction between rotational kinetic energy and translational motion, resulting in the reversal of spin direction, providing insight into complex rotational dynamics.
PIRA DCS Number
1M40.90