BASIC CONCEPTS AND THE LAWS OF GASES
Adam Smith's Wealth of Nations was published in the year 1776. Seven years earlier, James Watt
(1736-1819) obtained a patent for his version of the steam engine. Both men worked at the University of
Glasgow. Yet, in Adam Smith's great work the only use for coal was in providing heat for workers i. The
machines of the eighteenth century were driven by wind, water and animals. Nearly 2000 years had
passed since Hero of Alexandria made a sphere spin with the force of steam; still fire's power to generate
motion and drive machines remained hidden. Adam Smith (1723-1790) did not see in coal this hidden
wealth of nations.
The steam engine revealed a new possibility. Wind, water and animals converted one form of
motion to another. The steam engine was fundamentally different: it converted heat to mechanical
motion. Its enormous impact on civilization not only heralded the industrial revolution, it also gave birth
to a new science: thermodynamics. Unlike the science of Newtonian mechanics -- which had its origins
in theories of motion of heavenly bodies -- thermodynamics was born out of a more practical interest:
generating motion from heat.
Initially, thermodynamics was the study of heat and its ability to generate motion; then it merged
with the larger subject of energy and its interconversion from one form to another. With time,
thermodynamics evolved into a theory that describes transformations of states of matter in general,
motion generated by heat being a consequence of particular transformations. It is founded on essentially
two fundamental laws, one concerning energy and the other, entropy. A precise definition of energy and
entropy, as measurable physical quantities, will be presented in the second and third chapter respectively.
In the following two sections we will give an overview of thermodynamics and familiarize the reader with
the terminology and concepts that will be developed in the rest of the book.
Every system is associated with an energy and an entropy. When matter undergoes
transformation from one state to another, the total amount of energy in the system and its exterior is
conserved; total entropy, however, can only increase or, in idealized cases, remain unchanged. These