Minimal Six-Dimensional Light Null Entity with Tetrahedral Coupling Structure

We present a minimal six-dimensional (6D) null entity as an intrinsic geometric description of light, unifying propagation, polarization, phase, and frequency within a single closed manifold. Experimentally observed pairwise, triple, and quadruple couplings among these degrees of freedom define a tetrahedral coupling structure corresponding to a minimal closed information topology. This structure gives rise to an invariant geometric scaling relation for the speed of light C = (αk0)-1, thereby identifying C as the consequence of topological closure rather than a postulate. Observed optical phenomena, including apparent discreteness in measurement and wave-particle duality, arise as projections of the 6D entity into four-dimensional (4D) spacetime. The framework predicts quantitatively measurable deviations governed by a universal quadratic scaling law and experimentally falsifiable signatures beyond conventional quantum electrodynamics.