ABSTRACT
All quantum physical phenomena are maximally closed. Thus, if a photon emitted by a source later is registered in a detector, it is not meaningful “to try to find out what might have happened to the photon on its travel from source to detector.” To find out means to make an experiment. Hence, if a new detector is placed somewhere on the photon route, one has a new phenomenon. In a double-slit experiment the wave interference disappears if one tries to determine which way the particle went. Such mutually exclusive (complementary) particle and wave experiments, represent in the words of Bohr [27], “a rational generalization of classical physics.” To obtain human knowledge of the photon we must make observations.
