Try the following experiment. Find a mercury-vapor street light or other mercury vapor light. Holding your eyes straight ahead, quickly move your head to one side or the other. You will actually see the flicker. If you can find one, you can do the same experiment with a drive-in theater from a distance of, say, a mile. However, that is a much lower rate--24 frames a second.
I think the same effect can be observed with sodium lamps.
Florescent lighting is worse. While it also goes on and off 120 times a second when being fed with 60-cycle AC, there are often sub-harmonics that give amplitude changes at a lower, more easily perceived frequency.
So it is not unreasonable that one can observe AC power cycles, even if only occasionally.
Try the following experiment. Find a mercury-vapor street light or other mercury vapor light. Holding your eyes straight ahead, quickly move your head to one side or the other. You will actually see the flicker. If you can find one, you can do the same experiment with a drive-in theater from a distance of, say, a mile. However, that is a much lower rate--24 frames a second.
I think the same effect can be observed with sodium lamps.
Florescent lighting is worse. While it also goes on and off 120 times a second when being fed with 60-cycle AC, there are often sub-harmonics that give amplitude changes at a lower, more easily perceived frequency.
So it is not unreasonable that one can observe AC power cycles, even if only occasionally.