Illusion of Rotation

Click the Play button to start the animation. You can pause the animation at any time with a click on the Pause button. All the white points move along one of the straight white diameters. For each one of the points there is no rotation involved, it just moves repeatedly back and forth in 1 dimension. But if you look at all the points they seem to be part of a rotating circle.

Video with explanation (jump to 4:45)