Scales, Time, and Structural Coherence in a Single Universe An operational framework for scale-dependent regimes

This work develops a rigorous conceptual framework for understanding time, scale, and coherence in a single universe without invoking a universal temporal parameter. Rather than treating physical theories as competing descriptions of reality, the treatise formalizes them as scale-dependent regimes, each governed by its own operational notion of time and structural coherence. Time is defined operationally as the minimal ordering function required to sustain coherent processes within a regime. Transitions between scales are shown to arise from structural saturation and loss of regime manageability, necessitating the emergence of new collective variables and a new temporal ordering. What persists across these transitions are not entities or laws, but structural invariants: relational coherence, viability, localized causality, information as constraint, and critical thresholds. The framework demonstrates how multiple operational times can coexist without contradiction, formalizing conditions under which partial synchronization between scales is possible and when it must fail. Apparent paradoxes—such as the absence of a universal present, the tension between quantum and relativistic descriptions, irreversibility, and the interpretation of singularities—are reinterpreted as consequences of applying descriptions outside their appropriate regimes. This treatise is intended as a foundational and unifying conceptual contribution. It does not propose a new physical theory or predictive model, but provides a coherent structural language for organizing existing physical descriptions and clarifying their domains of validity across scales.