Notes on Thermodynamics

Thermodynamics (from the Greek thermos meaning heat and dynamis meaning power)
is a branch of physics that studies the effects of changes in temperature, pressure, and
volume on physical systems at the macroscopic scale by analyzing the collective motion
of their particles using statistics. Roughly, heat means "energy in transit" and dynamics
relates to "movement"; thus, in essence thermodynamics studies the movement of energy
and how energy instills movement. Historically, thermodynamics developed out of the
need to increase the efficiency of early steam engines.
The starting point for most thermodynamic considerations are the laws of
thermodynamics, which postulate that energy can be exchanged between physical
systems as heat or work. They also postulate the existence of a quantity named entropy,
which can be defined for any system. Central to this are the concepts of
system and surroundings. A system is composed of particles, whose average motions
define its properties, which in turn are related to one another through equations of state.
Properties can be combined to express internal energy and thermodynamic potentials are
useful for determining conditions for equilibrium and spontaneous processes.

Quotes
 "Thermodynamics is the only physical theory of universal content which,
within the framework of the applicability of its basic concepts, I am
convinced will never be overthrown." — Albert Einstein
 "The law that entropy always increases - the Second Law of
Thermodynamics - holds, I think, the supreme position among the laws of
physics. If someone points out to you that your pet theory of the universe is
in disagreement with Maxwell's equations - then so much the worse for
Maxwell's equations. If it is found to be contradicted by observation - well.