Physical Applications of Target Determinability under Partial Causal Observation Quantum Measurement, Thermodynamic Coarse-Graining, and Black-Hole-Inspired Finite Models

This companion paper applies the published target-determinability framework $(\mathcal{F},\Omega ,D)$ to three classical problem domains in physics: finite quantum measurement histories, thermodynamic coarse-graining, and black-hole-inspired finite evaporation models. For each domain, we construct an admissible physical reduction and derive structural determinability corollaries using the same imported criterion: a target is zero-error determinable from an observation iff the observation partition refines the target partition (ΠΩ⪯ΠD ). In the quantum domain, we obtain a zero-error incompatibility statement for target properties not resolved by a chosen measurement. In thermodynamics, we show that macroscopic observables generally fail to determine microscopic targets while coarse thermodynamic targets survive. In the black-hole-inspired toy model, early radiation observations fail to determine an interior target, while later cumulative observations succeed. We provide finite verification tables and a runnable checker logic for all three domains. The paper does not claim a new fundamental law of physics, nor does it resolve the full black hole information paradox. Its contribution is narrower and reviewable: explicit domain reductions, structural corollaries, and finite examples showing how the published determinability framework can be used in physical settings.