2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/166512We formulate the 2-body problem of electrodynamics using functional differential equations, and explain the peculiar features of these equations which indicate a paradigm shift in physics. We examine the possible empirical existence of advanced interactions using various absorber theories of radiation. Functional differential equations were connected to quantum mechanics in a subsequent paper in this series and in later publications.24 pages, 5 figures. New prefatory note addedGeneral Physicstext