A Resonant-Cavity Interpretation of the Double-Slit Experiment Without Wavefunction Collapse or Nonlocality

The double-slit experiment is typically presented as evidence for the non-classical nature of microscopic particles, especially when performed in the single-particle regime. However, the interference pattern that emerges on the detection screen is generated by wave propagation through two structured apertures, each acting as a narrow resonant cavity supporting longitudinal modes of a scalar field. In this work we derive the outgoing fields from the slits directly from boundary conditions and show that their superposition yields the standard far-field intensity profile of diffraction theory. The remaining aspect of the experiment — namely discrete, localized detection events — is accounted for by a minimal discrete-event model in which the continuous classical field drives quantized energy transfers at the detector. This approach is fully classical, requires no collapse postulate or nonlocality, and remains compatible with all known data. It clarifies which features of the experiment arise from field propagation and which arise from the discrete nature of detection.