If there's a flash of light near a moving object, the flash appears to lag a little behind.
In this movie there are three rotating dots. On one frame four addittional dots are flashed. When this happens all the dots are physically aligned, however they do not look aligned - the rotating dots seem to be ahead of the flashed dots.
Accessed: 4123 times Created: Wednesday, 2nd December 2009 by paulj Modified: Thursday, 8th November 2012 by paulj