The study of Thermodynamics is not a new discipline in physics.
For most of its history, Thermodynamics and its postulates and equations
had little theoretical basis but were accepted because they were well
verified by experiment. However, with the advent of quantum mechanics
in the early 20th Century, quantum-level explanations were formulated
that could explain the macroscopic behaviors of thermal systems.
For this reason, we begin our treatment of Thermodynamics with a look at
the quantum basis for the statistics that govern macroscopic behavior.
Do not fear if you don't understand Quantum Mechanics; we won't focus on
that aspect of the physics but instead will utilize the quantum way of
thinking about the state of a system. We will examine the
Fundamental Assumption of Thermodynamics and investigate its
application to probability via the multiplicity function. We will
close our quantum inspection by learning about the average value of
a variable in an ensemble.
We delve into the heart of Thermodynamicsm, then, by defining the
entropy and temperature of a system, making sure to
distinguish between the conventional and fundamental definitions
of these two variables. We'll close by looking at the 3 Laws of
Thermodynamics that govern our approach to the subject.