# Entropy **Domain:** Thermodynamics / Information Theory **Doc Type:** Scientific Concept Node **Maturity:** Established **Related:** [[Information Theory]], [[Time Asymmetry]], [[U10 Thermodynamic Data Classes]] --- ## Definition **Entropy** quantifies multiplicity, uncertainty, or the distribution of possible states, with distinct but mathematically related uses in thermodynamics and information theory. Thermodynamic entropy concerns physical state and irreversible processes; information entropy concerns uncertainty in a probability distribution. ## Continuity relevance Living neural systems preserve organized, history-dependent states through ongoing energy and matter exchange. A continuity model must avoid treating informational description as if it automatically captures the thermodynamic process that sustains the described system.