Modern physics possesses extraordinarily successful mathematical descriptions of quantum phenomena, elementary particles, fields, inertia, and gravitation, yet these domains remain ontologically fragmented. Quantum theory describes structured possibility without supplying a universally accepted account of how definite identity arises. Particle physics classifies stable and unstable excitations but does not fully explain why field structure condenses into persistent particlehood. General relativity describes gravitation geometrically, while the equivalence of inertial and gravitational mass remains foundationally imposed rather than derived from a deeper common ontology. Closure physics is a framework for unifying these domains. Its central claim is that every physically admissible state is a structured configuration of closure and nonclosure. Closure is not isolation, but the recurrent retention of relation sufficient for identity, persistence, and localized organization. Nonclosure is not formlessness or absence, but the continued extension of structured relation beyond any completed local identity. Physical reality therefore occupies neither absolute closure nor absolute nonclosure. Every physical state retains sufficient closure to possess structure and sufficient nonclosure to remain relationally embedded. Within this framework, fields are predominantly extended relational structures; quantum states are structured but incompletely localized closures; particles are recurrently stabilized partial closures; measurement is contextual reclosure; inertia is resistance to reconfiguration of a localized closure’s relation to the surrounding continuum; and gravitation is the universal field structure of retained nonclosure among localized closures. The equality of inertial and gravitational mass is interpreted as evidence that inertia and gravitation arise from complementary aspects of the same closure–nonclosure interface. The framework also motivates a conditional antigravity no-go theorem: if massive identity, inertial response, and gravitational participation are co-generated by one closure–continuum interface, gravitational coupling cannot be independently eliminated while the complete original massive closure is preserved. A narrower escape condition remains possible only through finite anisotropic reconfiguration of coupling that preserves matter closure, retains nonzero continuum participation, couples to an external gradient, and respects energy–momentum conservation. The framework is presented as an ontological and formal research program rather than as a completed theory of everything. It identifies primitive objects, admissibility conditions, regime maps, theorem-like constraints, and derivational obligations. A completed theory must recover quantum mechanics, relativistic field theory, particle representations, gauge interactions, general relativity, the equivalence principle, classicality, and thermodynamics while producing at least one novel quantitative prediction. Keywords: closure physics; nonclosure; quantum foundations; particle ontology; gravitation; inertia; measurement; relational ontology; unified physical theory; theory of everything
Philip Lilien (Sat,) studied this question.