How does it take a diffraction pattern to appear?
suppose a light with intensity as equal as passing a photon per second.
Classical physics tells us a diffraction pattern appears as fast as the light reaches a screen but quantum physics tells that if the intensity of light is very low as a photon per second, the diffraction pattern takes many times because we must wait lots of seconds for lots of photons to reach a detector(suppose we put ,say, a photon detector instead of the screen )
Is there any experiment to measure the time of pattern appearance?