A Relational Resolution of the Duality of Matter and Radiation

Any physical experiment must be described relationally consistent: observations are always made from a reference frame that is either co-moving with the system under study (zero relative velocity) or moving with respect to it (non-zero relative velocity). This applies equally whether the observer is associated with the entity under observation (e.g. an electron beam) or with the apparatus (e.g. a detector).a These are the only possible relational viewpoints, and consistency requires that one such viewpoint be maintained from the initial to the final stage of the experiment. The observer must either remain at rest relative to the apparatus or remain at rest relative to the particles, but cannot switch relational roles midway. Failure to maintain this consistency introduces interpretational difficulties that are often taken to reflect the “dual” nature of matter and radiation. In the initial stage of the double-slit experiment, the observer is implicitly treated as co-moving with the incoming electron beam, effectively assigning zero relative velocity between observer and electrons. However, in the final stage at the detection screen, the same observer is implicitly assumed to have a zero relative velocity with respect to the detector. The implicit assumption that the observer of the experiment can simultaneously be co-moving with the detector, and co-moving with the electrons, is the inconsistency. The relational viewpoint is changed between the initial and final parts of the same experiment without explicit justification. This inconsistency in the choice of relational reference frame constitutes the conceptual cause of the conclusion traditionally expressed as the wave–particle duality. I conclude this is the relational resolution to the mysterious ”wave– particle” duality of matter and radiation. The Wave-Particle Duality has always been framed as the intrinsic mystery of quantum physics. I revisit two foundational experiments–the Davisson–Germer electron scattering experiment (1927) and the Merli–Missiroli–Pozzi (MMP) biprism interference experiment (1976). I provide compelling evidence for a unified physically grounded relational resolution for that perplexing mystery. By analyzing the conditions under which interference patterns emerge, it is argued that wave-particle duality is not intrinsic to individual particles but arises from coherent ensembles of monoenergetic, indistinguishable quantum entities. The wave nature is precived by a rest-observer co-moving with the entity under observation. The particle nature is the relative view of a non co-moving observer with non-zero relative velocity. This interpretation challenges conventional mechanism and quantum narratives.