Decoherence Transition

A Decoherence Transition is the critical transition in which the substrate's entropy exceeds the threshold for maintaining quantum coherence, so coherence is lost and behavior passes from the quantum to the classical regime. It is the first of the book's three Transition Classifications, each triggered when entropy crosses a different critical value: decoherence at the quantum threshold, Structural Collapse at the structural threshold (null well formation), and dimensional emergence at the dimensional threshold (new dimensional substrates). All three thresholds follow the Critical Entropy Threshold, which scales exponentially with the ratio of recursive tension to a characteristic recursion scale, so the onset of decoherence is set by how much recursive tension the substrate carries. The book states the condition as S > S⊡, where S is the substrate entropy and S⊡ the entropy threshold for quantum coherence; in this section entropy is tagged [𝕃³]. The Decoherence Transition connects to Critical Transitions, Transition Classifications, Structural Collapse, Critical Entropy Threshold, Decoherence Mechanisms and Classical-to-Quantum Transition Dynamics.