# Time Asymmetry **Domain:** Thermodynamics / Dynamical Systems **Doc Type:** Scientific Concept Node **Maturity:** Established Concept, Specialized Continuity Application **Related:** [[U10 Thermodynamic Data Classes]], [[Information Theory]], [[Entropy]] --- ## Definition **Time asymmetry** describes processes whose evolution distinguishes past from future, commonly through irreversibility, entropy production, causal ordering, or history-dependent state. Biological systems maintain organization through continuous energy and matter exchange rather than static equilibrium. ## Continuity relevance An emulation may require not only a structural state but sufficient dynamic and historical variables to reproduce how that state changes. U10 modeling uses time asymmetry to keep those constraints visible.