Bob Dobbs wrote:
dave wrote:

Incandescent lamps turn on and off 60 times a
second.

Not hardly

They indeed do.

Could see it a mile away with a stroboscope.

A stroboscope doesn't see any further
than its own calibrated pulse will illuminate.

Calibrated pulse? A stroboscope is essentially a calibrated shutter.
Nothing more. You heterodyne it against the 60 Hz flicker of the lamps.

http://en.wikipedia.org/wiki/Stroboscope