Can you detect the direction of motion? Crank the handle to set the experiment in rotation. Look at the two attached spirals. Are they moving? Look carefully at the two metal rings hanging on the spirals. Are they moving?
The double spiral consists of two joined spirals with different diameters and directions of movement. There are two metal rings hanging from the two joined spirals. If you follow the movement of the metal rings along the spiral, the direction of movement is clearly visible. One of the spirals moves inwards, while the other one moves outwards. Because they are joined together, the rings move round and round on the spirals.