I will venture a guess off the top of my head, but I think there is a
literature on it. (I don't have time to look it up.)
Backward appearing rotation of wheels (I have also observed this in the
rotor of a jet engine) implies a periodicity in the visual system that
matches the period of rotation of the object.
Donald McBurney
(I am sure Ron Blue will attribute it to correlational opponent
processing somehow.)
Richard Platt wrote:
> A student in Intro asked about why when you are looking at
> the wheels of a moving car it can sometimes appear that the
> wheels are turning in the opposite direction of the car's
> movement. I have heard an explanation of this kind of
> phenomenon when viewed in a film or under artificial
> lighting that relies on having a rotation rate that is a close
> match to the flicker rate of the artificial light. However,
> I can't explain why it would occur under natural light.
> The sun doesn't have a flicker rate. Can anyone
> help me with this question?
>
> Richard Platt
> St. Mary's College of Maryland
