Uncertainty as a Diagnostic of Admissibility and Coherence

Uncertainty appears across physics in contexts ranging from quantum measurement and wave interference to chaotic dynamics and the breakdown of effective descriptions. Despite this ubiquity, it is often conflated with randomness, noise, or epistemic limitation. This work reframes uncertainty as a diagnostic signal rather than a dynamical cause. Two diagnostic quantities are introduced: allowity, the effective extent of admissible histories consistent with constraints, and coherence, the degree of phase compatibility among those histories. Together, these quantities classify when physical descriptions remain stable, when organized interference persists, and when abrupt reorganization or chaos emerges. The framework does not modify existing theories, uncertainty relations, or probabilistic formalisms. Instead, it provides a conservative, framework-neutral lens for identifying structural limits of predictability and regions where modeling assumptions become brittle.