I have a lay question that needs answering please. If a photodetector can display a single 'white dot blip' where a single photon has struck it, how can this be explained without requiring a physical size of the incident photon? Side Questions 1) Does a photon of higher energy leave a smaller 'blip' than a lower energy photon would? 2) Does a photodetector measure any properties of an incident photon other than its energy? 3) Can a photon with a wavelength greater in size than the slit its passing through be detected by a photodetector? 4) Will ZapperZ answer this post, chew me up, make me feel bad and enjoy bashing me for the nth time? (please don't answer this one ) Anyhoo, answers appreciated, ty.