Suppose that I have a source of monochromatic light of which I can lower that intensity so that it emits one photon, say, per minute. At the other end of the beam I have some kind of photoelectric detector that records the arrival of each photon. It seems like one could construct a detector to record the arrival time of each photon. But the Heisenberg Uncertainty Principle says that because the light is monochromatic (one precise frequency) then we cannot pin down the photons in time. Does that mean that it is impossible to construct a detector to record the “precise” arrival time of monochromatic photons? Thank you in advance.