Physics Lournal

This is the way in which the individuality of photons are preserved, although this is only doable because we abandon the determinism, of classical theory. The most that one can predict is the probability of the occurrence of each outcome.

Questions about what decides whether the photon is to go through or not and how it changes its direction of polarization when it does go through cannot be investigated by experiment and should be regarded as outside the domain of science.

I disagree highly with this quote, though I accept from the literature/pedagogy that "hidden variables" are not at play/responsible.

Referenced in

The Principle Of Superposition

The information we have about them is that they each are located in the region of space through which the beam is traveling, and they have a momentum which is given by the frequency times a universal constant, according to the photo-electric law. This information constitutes what is called a translational state.

The Principle Of Superposition