Why do car wheels seem to be turning backward on TV?

Answer 1

It's an optical illusion. I noticed it often as a child watching Western movies - sometimes it seemed as if the wagon wheels were turning backwards as they tried to outrace the Indians.. I believe it has to do with the frames-per-second speed of a film camera and the rotational speed of the wheel - at some point a relationship exists where the wheel appears to be turning normally - and then as the wagon or car or whatever, speeds up, it gets ahead of the speed of the film moving past the lens of the camera somehow, and the wheel appears to be turning backwards. I don't think you'd notice this in a video or other mode of capturing moving images - it's probably only an artifact of film cameras which have film moving past an aperture at a fixed rate.