Gravity as Closure Geometry: A Law-Level Unification of Light, Gravitational Radiation, and Universal Free Fall

This paper presents a law-level structural classification of gravity within the Tier-0 admissibility framework, unifying gravitational radiation, everyday gravitational motion, and quantum-completion constraints without modifying general relativity or introducing new dynamics. Rather than treating gravity as a single phenomenon, the paper shows that what is commonly called “gravity” comprises distinct admissible sector roles once boundary structure, persistence, and global closure are enforced. In particular, it demonstrates that: Gravitational radiation propagates at the invariant speed of light not by assumption, but by structural necessity. Any causal influence that propagates without forming records during transit must occupy the null (record-silent) sector fixed by closure. Gravitational waves therefore share the same causal boundary as light because they belong to the same admissible transport class. Everyday gravitational phenomena (free fall, universality of acceleration) arise from motion in Ω-stable closure geometry, not from a force mediated by an object-specific charge. The equivalence principle is reinterpreted as a sector consequence: trajectories in closure geometry are blind to the internal, record-bearing details selected by dissipative processes. Gravity is neither “just another quantum field” nor an incomplete classical interaction, but a geometric closure structure whose quantum-consistent completion is constrained at the spectral and operator level. The paper outlines how quantum gravity should be formulated as a spectral completion problem (stability, semiboundedness, and coarse-graining invariance), rather than as a naive graviton gas. The analysis cleanly distinguishes: null, record-silent transport (light and gravitational radiation), anchored, record-bearing curvature (ordinary matter and tidal gravity), localized record-silent curvature loads (dark matter), and global closure-dominant background curvature (dark energy). Importantly, the paper does not propose new particles, modified field equations, or speculative dynamics. Its contribution is classificatory and unificatory: it explains why gravitational phenomena have the causal, universal, and quantization-resistant features they do, by showing how those features follow from admissibility at the level of law structure. Clear falsifiability criteria are provided, separating tests of Einstein’s equations from tests of the sector classification itself. This work is intended for readers interested in the foundations of gravity, causal structure, and quantum gravity, and is compatible with standard general relativity, semiclassical gravity, and existing observational constraints.