Light as a Boundary Mode in Phase-Selective Realization

This paper examines the ontological status of light within the framework of phase-selective realization. While light is conventionally described as a propagating wave or particle, such interpretations introduce persistent conceptual tensions, including the absence of a rest frame, proper time, and observable intermediate states. We show that these features are not anomalies but direct consequences of the realization structure underlying physical phenomena. By analyzing relativistic kinematics, classical electrodynamics, and quantum field theory, we demonstrate that none of these formalisms require light to exist as a traveling physical object. Instead, light emerges as a boundary mode: the saturation of the null realizability condition separating admissible from non-admissible event sequences. Within this view, wavelengths characterize spatial phase structure, frequencies arise only through projection onto realized temporal reference frames, and energy appears exclusively at interaction, not during propagation. The framework preserves all empirical predictions of Maxwell theory, relativity, and quantum electrodynamics, while offering a unified interpretational account consistent with phase-selective gravitation, gravitational lensing, and black hole boundary phenomena.