Harmonic Physics: Light as Recursion-Neutral Propagation

Version 2.0 is a substantive scientific revision of the original 2025 paper. It retains the title “Light as Recursion-Neutral Propagation” while replacing the earlier proposal that light occupies a special harmonic layer outside the temporal, curvature and material organisation of physical systems. Established electromagnetism remains the governing physical baseline. Electromagnetic radiation possesses spectral, phase, polarisation, amplitude, coherence and energy-momentum structure. Lightlike propagation is embedded in relativistic spacetime, curvature can alter propagation, coherence depends on source preparation and measurement, and electromagnetic radiation interacts physically with matter. The revised Harmonic Physics account does not replace Maxwell electrodynamics, quantum electrodynamics or relativity. Recursion-neutral propagation is redefined as a bounded organisational hypothesis. At a declared resolution, electromagnetic propagation may be represented as the continuity of one propagating organisation across non-identical but sufficiently compatible local field states, without treating every intermediate state as a newly formed persistent material whole. This does not imply state invariance, zero propagation time, exemption from curvature or interaction, global coherence, a photon rest frame, or persistent photon identity through scattering, conversion or absorption. The revised explanatory hierarchy is: phase differentiation → relational organisation → relative phase evolution where defined → electromagnetic mode content → observer-conditioned registration. These relations express logical dependency rather than temporal succession. Differentiation is treated as logically prior to relative phase rate because distinguishable components or relations must first be declared before their phase difference or rate of evolution can be defined. The electromagnetic spectrum is then interpreted as the distribution of physically available and observer-resolvable mode content, not as a set of separate ontological realms. Visible light is one biologically accessible band within the continuous electromagnetic spectrum. Instruments extend observer access into radio, infrared, ultraviolet, X-ray and gamma-ray regimes through distinct coupling and transduction chains. Darkness is therefore treated as insufficient visible-band registration under declared conditions, not as an opposing physical substance. Heat is likewise not identified with light; thermal radiation is one electromagnetic channel of energy transfer among others. The evidence remains bounded. JPR-01 demonstrates that controlled phase evolution can produce an electromagnetic radiation record in a conventional Josephson-junction/resonator model, but the matched conventional model reproduces the result, leaving it correspondence-only. Interferometry establishes that relative phase can generate bright and dark detector structure under physical and measurement constraints. EPR-P04 supplies a separate cross-domain example in which multiple known components produce one observer-resolved relational-frequency record, but it does not establish an electromagnetic formation mechanism. The decisive open requirement is a Phase-native model that independently recovers Maxwell/QED observables, Lorentz-invariant propagation, spectrum, polarisation and energy-momentum behaviour, or produces a preregistered prediction not already fixed by the complete conventional source–path–detector model. Until that bridge is supplied, recursion-neutral propagation and differentiation as the origin of spectral organisation remain open organisational hypotheses rather than established physical laws.