This is interesting , I have been giving the problem of devising an experiment to ascertain the wave – particle duality some more thought and have come to the conclusion that it should be relatively simple to do. Just as in the “Quantum Encryption “

Setup described at the beginning of this thread , a pair of entangled photons is created using the parametric down conversion method. It should be noted that at this time the photons can have any polarization , all that is certain is that they will have opposite polarizations. (This has been amply demonstrated by the fact that such a quantum encryption has been carried out.) One of these photons is sent to a spatially separated location ( i.e., a location sufficiently distant that light takes a perceptible time to reach it) at B and the other photon is kept at A. The photon kept at A maybe made to travel ( through an optical cable etc., ) for a distance longer than the distance to B. The photon at B is polarized using a vertical filter , and then its presence or absence is detected and a similar vertical polarizer and detector is placed in front of A. There are now only two possibilities , if the photon at B is detected then the photon at A will not be detected and vice versa. Here is the important thing , if after 100 or so repetitions there is a 100% correspondence (i.e., photon at B no photon at A and vice versa etc., ) then wave particle duality , the wave function and everything else in Quantum Mechanics is validated. If however there is an appreciable discrepancy in the results , then it proves once and for all , that wave particle duality is false , that the wave function at least to do with photons does not exist and that faster than light transactions and non locality are a myth. The question is , since the equipment already exists to carry out such an experiment , why has it not been done and why have the results not been widely disseminated? After all if the results are positive it would be the greatest vindication of Quantum mechanics ever.