Carathéodory's principle

Carathéodory's principle

[‚kär·ə‚tā·ə′dȯr·ēz ′prin·sə·pəl]
(thermodynamics)
An expression of the second law of thermodynamics which says that in the neighborhood of any equilibrium state of a system, there are states which are not accessible by a reversible or irreversible adiabatic process. Also known as principle of inaccessibility.