Bill S.

I'm not sure that I have ever seen that effect that isn't in a moving picture of some sort, or created by a stroboscopic light source. However, I think that under certain conditions you might see something like that if you were looking at something with the light coming from something like a flourescent lamp, which can have a sort of a 60 Hz (50 Hz many places) blink to it. I do seem to recall that you used to be able to buy a gadget to check the speed of the turntable on your record player. It came with a little disk that you slipped over the spindle of the turntable. The disk had radial lines engraved on it. You also got a special little lamp that used something like neon. The gas would be energized at a 120 Hz (or a 100 Hz rate in may countries) rate (once for each half of the power line frequency). If your turntable was turning at the correct speed the lines on the disk stood still, otherwise they rotated one way or the other. You may have been seeing something like that.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.