The heat $delta Q$ was the conundrum of the ancient age of Thermodynamics, until Boltzmann's H-theorem and Botzmann Principle (BP) $S=kappa ln W$, made it possible to express the entropy in terms of the number $W$ of available states. At this stage, the Second Principle $delta Q=TdS$ could be used to calculate the heat, even in the absence of a clear relationship between what Thermodynamics calls "heat exchange" and the forces acting at a microscopic level. We recover Max Born's definition of heat exchange, as the mechanism that modifies the energy levels' populations. From this definition, BP can be demonstrated, without recursion to the H-theorem, as shown by Born itself. Dragging to the light Born's contribute to Statistical Thermodynamics, modestly relegated by the Author to a textbook appendix, is the main aim of the present note. The second one is showing that Born's definition of heat exchange follows from the notion of generalized scattering process.
A microscopic view of heat exchanges: Born's contribution to the demonstration od Boltzmann Principle
FERRARI, LORIS
2013
Abstract
The heat $delta Q$ was the conundrum of the ancient age of Thermodynamics, until Boltzmann's H-theorem and Botzmann Principle (BP) $S=kappa ln W$, made it possible to express the entropy in terms of the number $W$ of available states. At this stage, the Second Principle $delta Q=TdS$ could be used to calculate the heat, even in the absence of a clear relationship between what Thermodynamics calls "heat exchange" and the forces acting at a microscopic level. We recover Max Born's definition of heat exchange, as the mechanism that modifies the energy levels' populations. From this definition, BP can be demonstrated, without recursion to the H-theorem, as shown by Born itself. Dragging to the light Born's contribute to Statistical Thermodynamics, modestly relegated by the Author to a textbook appendix, is the main aim of the present note. The second one is showing that Born's definition of heat exchange follows from the notion of generalized scattering process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
