This paper completes the constructive reformulation of classical electromagnetism initiated in Paper I and extended in Paper II. It addresses the question of time dependence, showing that it does not arise from acceleration—which is not a primitive in this theory—but from the cancellation condition Eₘ = -Eₛ in the atomic potential scenario. Choosing a fixed surface in the nucleus rest frame, Gauss's law together with the continuity equation yields the dynamical relation ₜ Eₘ = J /. Combining this with the steady-state curl equations derived in Paper II gives the full time-dependent Maxwell equations: Eₘ = -ₜ B and B = c^-2 ₜ Eₘ. From these, the homogeneous wave equation ² Eₘ = c^-2 ₜ² Eₘ follows directly. Key insights include: the displacement current emerges naturally rather than as an ad-hoc addition; the wave equation is homogeneous, separating generation from propagation; light is a wave of the field under the cancellation condition, not detached radiation; and the atomic potential provides a natural setting for discrete light emission (spectra). This paper sets the stage for applications to atomic structure and quantum theory.
Akintunde Abiodun Olawale (Thu,) studied this question.