Double slit interference: Part I

Feynman referred to interference as "the only mystery," and we continue to pursue that idea here by examining the theory behind it with heightened scrutiny. Three interpretations are described: The standard model, Feynman's sum-over-paths, and Einstein's photon model. The standard model bases its arguments on the wave function and its subsequent collapse. The sum -over-paths model is equivalent to the standard model, but it explains interference by avoiding use of the wave function and its conceptual problems due to collapse. The Einstein model is the most challenging for it is revolutionary and intuitively demanding. We critique the three models by studying their treatment of polarized light. In Part II, the interference of low intensity light will be discussed. VC 2023 Physics Essays Publication.