8.1 Introduction: The Energy Conversion Doctrine Truism
It is a universally accepted truism that “everything that happens involves conversion of energy,” [1, 2] and that energy conversion processes are divided into two
kinds: one kind in the direction of spontaneous changes from energy of high-grade
form to energy of lower grade form eventually to heat, and the other in the reverse
direction including the conversion of heat into mechanical energy; whereas the
spontaneous or natural changes are limitless, the reverse-direction changes are
subject to strict limitation.
How did we arrive at this understanding on energy? There were three critical
steps. First, by 1850, Joule had succeeded to demonstrate equivalence correlation
between consumed mechanical work and produced heat [3] and, additionally proposed equivalence between “consumed” heat and produced mechanical work. The
equivalence principle (or, MEH) is not, however, an interconvertibility principle.
Carnot, earlier in his private writing, had argued that motive power could not be
created by mere destruction, or consumption, of the heat of bodies [4].
What happened in 1850–1854 was the second step: Joule, Clausius, and, finally,
Kelvin accepted that heat was a form of energy; with the “doctrine of heat energy,”
they made the inference that the doctrine of heat being a form of energy infers
“equivalence of heat and work” to be synonymous with “convertibility of heat and
work” (see Sect. 4.8). The MEH was thereby upgraded to the interconvertibility
principle: evidence of MEH correlation was accepted as evidence of causation. Any
doubt Carnot had had was swept away, as interconvertibility became the defining
characteristic of thermodynamics as Fermi put it, “Thermodynamics is mainly
concerned with the transformations of heat into mechanical work and the opposite
transformations of mechanical work into heat” [5]. The principle has the merit of
identifying in heat its apparent utility, which together with the discovery of petroleum as a new source of heat made possible the Second Industrial Revolution.
The third step was the result of Kelvin’s energy principle, which expanded the
meaning of the interconvertibility principle. We noted in Chap. 4 that the energy
principle itself was a self-evident proposition as declared by Kelvin in three General
Conclusions (only the first two, are reproduced here),
General Conclusion 1.There is at present in the material world a universal tendency
to the dissipation of mechanical energy.
General Conclusion 2.Any restoration of mechanical energy, without more than an
equivalent of dissipation, is impossible in inanimate material
processes, and is probably never effected by means of
organized matter, either endowed with vegetable life or
subjected to the will of an animated creature.
190
8 The Second Law: The Entropy Growth Potential Principle …
It is a universally accepted truism that “everything that happens involves conversion of energy,” [1, 2] and that energy conversion processes are divided into two
kinds: one kind in the direction of spontaneous changes from energy of high-grade
form to energy of lower grade form eventually to heat, and the other in the reverse
direction including the conversion of heat into mechanical energy; whereas the
spontaneous or natural changes are limitless, the reverse-direction changes are
subject to strict limitation.
How did we arrive at this understanding on energy? There were three critical
steps. First, by 1850, Joule had succeeded to demonstrate equivalence correlation
between consumed mechanical work and produced heat [3] and, additionally proposed equivalence between “consumed” heat and produced mechanical work. The
equivalence principle (or, MEH) is not, however, an interconvertibility principle.
Carnot, earlier in his private writing, had argued that motive power could not be
created by mere destruction, or consumption, of the heat of bodies [4].
What happened in 1850–1854 was the second step: Joule, Clausius, and, finally,
Kelvin accepted that heat was a form of energy; with the “doctrine of heat energy,”
they made the inference that the doctrine of heat being a form of energy infers
“equivalence of heat and work” to be synonymous with “convertibility of heat and
work” (see Sect. 4.8). The MEH was thereby upgraded to the interconvertibility
principle: evidence of MEH correlation was accepted as evidence of causation. Any
doubt Carnot had had was swept away, as interconvertibility became the defining
characteristic of thermodynamics as Fermi put it, “Thermodynamics is mainly
concerned with the transformations of heat into mechanical work and the opposite
transformations of mechanical work into heat” [5]. The principle has the merit of
identifying in heat its apparent utility, which together with the discovery of petroleum as a new source of heat made possible the Second Industrial Revolution.
The third step was the result of Kelvin’s energy principle, which expanded the
meaning of the interconvertibility principle. We noted in Chap. 4 that the energy
principle itself was a self-evident proposition as declared by Kelvin in three General
Conclusions (only the first two, are reproduced here),
General Conclusion 1.There is at present in the material world a universal tendency
to the dissipation of mechanical energy.
General Conclusion 2.Any restoration of mechanical energy, without more than an
equivalent of dissipation, is impossible in inanimate material
processes, and is probably never effected by means of
organized matter, either endowed with vegetable life or
subjected to the will of an animated creature.
190
8 The Second Law: The Entropy Growth Potential Principle …