Barber-Pole-Illusion

The barber pole illusion is an optical illusion of perceived movement, which is based on the aperture problem.

The barber pole illusion is one of the best-known motion illusions. It takes its name from the painted with blue and red diagonal stripe bars which are facing many hair salons to find in the U.S.. It is caused by the rotation of a vertical screw- shaped strip of the cylinder. This is not perceived by observers as a purely horizontal motion, but he interpreted it, depending on the direction of rotation, being hiked the strip up or down. This is due to the aperture problem, which states that for homogeneous lines that move within an otherwise empty field, their motion is always perceived as being perpendicular to the line orientation running.