What can you do here
Look closely at the pattern on the wheel. Start spinning it. Slowly increase the spinning speed. What are you seeing? Experiment by rotating the disc with various angular velocities in both directions. At a certain slow speed you will be under the impression that the object is three-dimensional. If you don’t see the third dimension straightaway, gaze at the spinning disc for a while.

How does it work
The sequence of lines and their thickness make you think the object is 3D. Thicker lines are interpreted as closer and thinner as more distant.

When you look at anything, either of your eyes gets a slightly different image, which enables your brain to assess the distance. This mechanism is the basis of depth perception. This perception, however, is also possible with a single eye because of a number of phenomena that the brain uses to interpret images. Relative object sizes or shadows may play a part.

Interesting facts
French artist Marcel Duchamp (1887–1968) used the stereoscopy (the illusion of depth) in 1935 in spinning cardboard wheels called Rotoreliefs. Two different designs of his are presented in our exhibition as ‘Colourful crater’ and ‘Wandering wheel’.