. "necessary heat" . . "Laws of thermodynamics" . "laws of thermodynamics" . "the second law of thermodynamics" . "firmly established in physics" . "second law of thermodynamics" . "first law of thermodynamics" . . "laws of statistical mechanics" . "Laws of thermodynamics" . "fourth law of entropy" . . "passive process" . . . "thermodynamic law" . "thermodynamics" . "Laws_of_thermodynamics" . . "principle of energetics" . . "law of thermodynamics" .