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The Helmholtz theorem of classical mechanics reads as follows: Let : be the Hamiltonian of a one-dimensional system, where : is the kinetic energy and : is a "U-shaped" potential energy profile which depends on a parameter . Let denote the time average. Let : : : : Then : == Remarks == The thesis of this theorem of classical mechanics reads exactly as the heat theorem of thermodynamics. This fact shows that thermodynamic-like relations exist between certain mechanical quantities. This in turn allows to define the "thermodynamic state" of a one-dimensional mechanical system. In particular the temperature is given by time average of the kinetic energy, and the entropy by the logarithm of the action (i.e.). The importance of this theorem has been recognized by Ludwig Boltzmann who saw how to apply it to macroscopic systems (i.e. multidimensional systems), in order to provide a mechanical foundation of equilibrium thermodynamics. This research activity was strictly related to his formulation of the ergodic hypothesis. A multidimensional version of the Helmholtz theorem, based on the ergodic theorem of George David Birkhoff is known as generalized Helmholtz theorem. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Helmholtz theorem (classical mechanics)」の詳細全文を読む スポンサード リンク
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