Connection between the Principles of Thermodynamics and the Conservation Laws: Physical Meaning of the Principles of Thermodynamics

L I Petrova

doi:10.4236/jamp.2018.612223

Abstract

It has been shown that the first principle of thermodynamics follows from the conservation laws for energy and linear momentum. And the second principle of thermodynamics follows from the first principle of thermodynamics under realization of the integrating factor (namely, temperature) and is a conservation law. The significance of the first principle of thermodynamics consists in the fact that it specifies the thermodynamic system state, which depends on interaction between conservation laws and is non-equilibrium due to a non-commutativity of conservation laws. The realization of the second principle of thermodynamics points to a transition of the thermodynamic system state into a locally-equilibrium state. Phase transitions are examples of such transitions.

Highlights

During the process of science evolution the concept of “conservation laws” in thermodynamics, physics and mechanics was taken different senses
The second principle of thermodynamics follows from the first principle of thermodynamics under realization of the integrating factor and is a conservation law
The significance of the first principle of thermodynamics consists in the fact that it specifies the thermodynamic system state, which depends on interaction between conservation laws and is non-equilibrium due to a non-commutativity of conservation laws

Summary

Introduction

During the process of science evolution the concept of “conservation laws” in thermodynamics, physics and mechanics was taken different senses. These are conservation laws that are described by differential equations or by the equations in terms of increments of physical quantities and governing variables From here on they will be referred as the balance conservation laws. In the field theory and in the theoretical mechanics “the conservation laws” are those that claim an existence of conservative physical quantities or objects. Such conservation laws are described by closed exterior skew-symmetric forms. That is; the concept of “conservation laws” is connected with the balance conservation laws, exact conservation laws and some regularities; the example of which are the principles of thermodynamics. That corresponds to an exact conservation law (the existence of entropy as a state function) and describes the transition of thermodynamic system to the locally-equilibrium state that is accompanied by emergence of some fluctuations

Connection the Thermodynamic Principles with Conservation Laws

Connection the Second Principle of Thermodynamics with Conservation Laws

Physical Meaning of the Principles of Thermodynamics

Conclusions