Light Speed as an Emergent Property of Electromagnetic Superposition

Polarization is treated as a secondary electromagnetic field rather than a property of matter. Within linear Maxwell theory and linear response, overlapping electromagnetic waves generate phase-delayed secondary fields whose superposition alters phase evolution and yields an effective refractive index. Electromagnetic waves therefore interact through the total field configuration they jointly create, and the effective local speed of light depends on the electromagnetic energy density of the environment. Refraction emerges as a consequence of field superposition and delayed response, without invoking particles, atoms, or nonlinear modifications of Maxwell's equations.