Can a Human See a Single Photon? (1996)
I’ve been aware of this fact as Feynman points it out in the course of the lectures, but find it totally nuts — there is some sense of scale I’m missing.Matter consists of discrete chunks, atoms, but these chunks are so infinitesimal and numerous that there is no question of seeing them and any effect involving a handful of them is far, far below the human scale.Light also comes in chunks, and the number of these chunks should be comparable to number of atoms since, e.g every single atomic transition generates a photon. Actually they should be far more numerous as they are massless and easily created, destroyed.Yet, somehow, they are not far below the human scale of detection — as few as 5 (!) results in a perceivable flash.What am I missing here? (Obviously this boils down to a numeric estimation and the numbers are what they are — my question is why do the numbers wind up even remotely in the human ballpark.)