Radiation, Vacuum, and Constraint Accumulation in the Universe An Operational Account of Motion, Inertia, and Cosmic Evolution

Radiation pressure and vacuum response are commonly described using force-based orparticle-exchange language that obscures the operational mechanisms by which matter andenergy interact. This paper reframes radiation and vacuum phenomena as constraint-basedprocesses, in which energy flux and boundary conditions condition the electromagnetic andspace-phase environments that bias allowed motion, energy flow, and storage. Part Idevelops this operational translation explicitly for radiation pressure and vacuum response,eliminating the need for force language while preserving established predictions. Part IIextends the same framework across cosmic history, assessing how gravity, angularmomentum, charge, radiation flux, vacuum response, and inertia collectively accumulatedas constraints over time. Special attention is given to the question of inertia as the energeticcost of restructuring conditioned space-phase, raising the possibility that inertia waseffectively lower in the early universe when fewer constraints had yet been laid down.Present-day cosmic behavior is then interpreted as a natural consequence of a universewith high constraint density and deep operational memory.