Chapter 3
Thermodynamics
Newtonian mechanics is a study of determination of location of points in space-time
(x, y, z and time) coordinate system after being subjected to external forces. Since
Newton’s 1687 formulations, many other mechanics theories were proposed. However, they are all based on Newton’s laws of motion and are referred to as Newtonian
mechanics. In this book, the term “Newtonian mechanics” is used to refer to all
mechanics theories that use Newton’s universal laws of motion.
In Newtonian mechanics formulation, the object being studied is assumed to be
ageless, and energy loss (entropy generation) is not considered.
Thermodynamics is about past, present, and future of objects, under given set of
conditions. Directly quoting Callen’s (1985) excellent description, “Thermodynamics is concerned with the macroscopic consequences of the myriads of atomic
coordinates that, by virtue of the coarseness of macroscopic observations, do not
appear explicitly in a macroscopic description of the system.” Therefore, thermodynamics is actually the study of nature at macroscopic scale that reflects what happens
at the atomic scale. However, “Among the many consequences of the ‘hidden’
atomic modes of motion, the most evident is the ability of these modes to act as a
repository for energy” Callen (1985).
Thermodynamics is a universal subject. As such, it is assumed that laws of
thermodynamics are universally valid for all systems at macro level under equilibrium conditions.
Therefore, we can treat any structure or system or any piece of material as a
thermodynamic system. The size of the system studied is very important for the laws
of thermodynamics. In this book, we are only concerned with continuum mechanics
where Newton’s laws are applicable. The boundary between quantum mechanics
and continuum mechanics is not an easily quantifiable one. There is a gray area.
However, continuum mechanics is the primary topic in this book.
When we treat a continuum system (solid or fluid), we will assume that it is a
closed system. This means that for a given time period (time increment), there is no
exchange of matter or energy with its surroundings. This can be considered as a fixed
© Springer Nature Switzerland AG 2021
C. Basaran, Introduction to Unified Mechanics Theory with Applications,
https://doi.org/10.1007/978-3-030-57772-8_3
73
Thermodynamics
Newtonian mechanics is a study of determination of location of points in space-time
(x, y, z and time) coordinate system after being subjected to external forces. Since
Newton’s 1687 formulations, many other mechanics theories were proposed. However, they are all based on Newton’s laws of motion and are referred to as Newtonian
mechanics. In this book, the term “Newtonian mechanics” is used to refer to all
mechanics theories that use Newton’s universal laws of motion.
In Newtonian mechanics formulation, the object being studied is assumed to be
ageless, and energy loss (entropy generation) is not considered.
Thermodynamics is about past, present, and future of objects, under given set of
conditions. Directly quoting Callen’s (1985) excellent description, “Thermodynamics is concerned with the macroscopic consequences of the myriads of atomic
coordinates that, by virtue of the coarseness of macroscopic observations, do not
appear explicitly in a macroscopic description of the system.” Therefore, thermodynamics is actually the study of nature at macroscopic scale that reflects what happens
at the atomic scale. However, “Among the many consequences of the ‘hidden’
atomic modes of motion, the most evident is the ability of these modes to act as a
repository for energy” Callen (1985).
Thermodynamics is a universal subject. As such, it is assumed that laws of
thermodynamics are universally valid for all systems at macro level under equilibrium conditions.
Therefore, we can treat any structure or system or any piece of material as a
thermodynamic system. The size of the system studied is very important for the laws
of thermodynamics. In this book, we are only concerned with continuum mechanics
where Newton’s laws are applicable. The boundary between quantum mechanics
and continuum mechanics is not an easily quantifiable one. There is a gray area.
However, continuum mechanics is the primary topic in this book.
When we treat a continuum system (solid or fluid), we will assume that it is a
closed system. This means that for a given time period (time increment), there is no
exchange of matter or energy with its surroundings. This can be considered as a fixed
© Springer Nature Switzerland AG 2021
C. Basaran, Introduction to Unified Mechanics Theory with Applications,
https://doi.org/10.1007/978-3-030-57772-8_3
73