Operational Mass-Energy Equivalence: Accessibility, Kinematic Cloaking, and Composite Probes

Arc III — Matter Paper 1 Title Operational Mass–Energy Equivalence: Accessibility, Kinematic Cloaking, and Composite Probes Zenodo DOI 10.5281/zenodo.18225809 This paper develops an operational reinterpretation of mass–energy equivalence grounded in finite accessibility rather than intrinsic substance. Mass is treated not as a protocol-independent property of matter, but as an emergent measure of how strongly a system suppresses the accessibility of external correlations. By analyzing composite probes, kinematic cloaking, and operationally defined response functions, the paper shows that what is conventionally identified as inertial or gravitational mass arises from accessibility renormalization induced by internal degrees of freedom. Systems with identical rest energy can exhibit distinct operational mass depending on probe protocol, resolution, and correlation structure. The framework reframes mass–energy equivalence as a statement about inference cost and signal degradation rather than ontological conversion between mass and energy. This perspective naturally accommodates composite systems, clarifies apparent paradoxes involving hidden internal structure, and sets the stage for no-go theorems regarding protocol-independent mass developed in subsequent papers. This work inaugurates the Matter Arc of the Finite Accessibility program and provides the foundational operational definition of mass used throughout later treatments of dark-sector cloaking, information-volume collapse, and composite-system renormalization. Keywords Finite accessibility; operational mass; mass–energy equivalence; composite systems; kinematic cloaking; inference limits; protocol dependence; foundations of physics Notes (Optional / Internal) Arc III — Matter Builds on Arc I–II accessibility framework Precedes: Operational Mass and Accessibility Renormalization in Composite Systems