(This is a preprint version of a technical paper. I’m making it available here in addition to the usual preprint servers. Questions/comments welcome.) Click here for the paper: Light Tight Box Preprint
Abstract: This paper discusses the nature of the boundary condition applying to the direct-action theory of fields, also known as the ‘absorber’ theory, first developed in a classical version by Wheeler and Feynman. The traditional understanding of these authors and others who followed is that the direct-action theory requires that ‘all emitted radiation be absorbed,’ or that ‘the universe is a perfect (or complete) of absorber of radiation,’ implying the need for a specific sort of cosmological boundary condition that may or may not obtain in our universe. It is pointed out that this interpretation requires critical scrutiny even at the classical level, and in any case does not apply to the fully quantum form of the direct-action theory (QDAT), which involves discrete energy transfers by way of photons. In the latter case, the absorption boundary condition describes a specific interactive relationship between emitters and absorbers that is independent of cosmological boundary conditions. Thus, the quantum direct-action theory does not require any special cosmological boundary condition in order for it describe the physical world.