Visualizing the Movement of the Celtic Stone as High School Students Activity

Abstract

The Celtic Stone (also known as a rattleback) is a semi-ellipsoidal shaped solid object which when spun rotates on its axis in a preferred direction. If spun in the opposite direction, it goes to the stop and reverses its spin to the preferred direction. As the movement of the stone is multidirectional it is a challenge to perform quantitative measurements of its motion characteristics. The work presents the experimental set-up and the procedure for collecting date of a rattleback motion as the high school students activity. Proposals for specific student actions and their benefits for learning were described in connection with the results obtained. Some preliminary results of video measurements performed with a specific metal rattleback and meant to visualize its motion are reported. Attempts to compare the results with predictions based on the numerical model of the situation are undertaken. The advantages and disadvantages of the measurement system are presented and discussed.