What happens to the oceans under the full moon? What flings you outward when your car cuts a corner too sharply? It's easy to visualize the effects of inertial movements with this device. Horizontal acceleration creates characteristic wave patterns as the colored liquid inside our transparent housing moves in the direction opposite to the acceleration. You can even measure the patterns with the imprinted horizontal and vertical grid. Includes hook and loop connector to attach to a dynamics car or rotating platform; imprinted grid lines; instructions. You need water and food coloring.