The Quantum Measurement Problem Revisited: A Structural Resolution and the Irreducible Role of the Born Rule

This note presents a structural resolution of the quantum measurement problem by decomposing it into three distinct physical layers: the persistence of quantum coherence, the emergence of a single definite classical outcome, and the origin of quantum probability. It provides physical explanations for coherence loss and outcome definiteness based on coordination limits, thermodynamic irreversibility, and information stability, without introducing new dynamics or observer postulates. The analysis further clarifies that the Born rule does not arise from measurement or macroscopic processing, but is an irreducible structural constraint governing microscopic quantum interactions. By correctly delimiting the scope of measurement theory, the note resolves longstanding conceptual confusion while remaining fully consistent with standard quantum mechanics.