Revisiting The Second Law of Energy Degradation and Entropy Generation: From Sadi Carnot's Ingenious Reasoning to Holistic Generalization

Abstract

Sadi Carnot's ingenious reasoning of reversible cycles (1824) laid foundations for The Second Law before The First Law of energy conservation was even known (Joule 1843) and long before Thermodynamic concepts were established in 1850s. A century later, Bridgman (1941) 'complained' that "there are almost as many formulations of The Second Law as there have been discussions of it." Even today, The Second Law remains so obscure, due to the lack of its comprehension, that it continues to attract new efforts at clarification, including this one.The Laws of Thermodynamics have much wider, including philosophical significance and implication, than their simple expressions based on the experimental observations -they are The Fundamental Laws of Nature: The Zeroth (equilibrium existentialism), The First (conservational transformationalism), The Second (directional transformationalism), and The Third (unattainability of emptiness). They are defining and unifying our comprehension of all existence and transformations in the universe. The forces, due to non-equilibrium of mass-energy in space (non-uniform 'concentrations'), causing the mass-energy displacement, thus defining the process direction, are manifested by tendency of mass-energy transfer in time towards common equilibrium --cause-andeffect forced tendency of equi-partition of mass-energy. It should not be confused with local creation of non-equilibrium and/or 'organized structures' on expense of 'over-all' non-equilibrium, by spontaneous and irreversible conversion (dissipation) of other energy forms into the thermal energy, always and everywhere accompanied with entropy generation (randomized equi-partition of energy per absolute temperature level).The fundamental laws of nature are considered to be axiomatic and many believe they could not be explained, proven or questioned. However, everything may and should be questioned, reasoned, explained and possibly proven. The miracles are until they are comprehended and understood.

The Elusive Nature of Entropy and Its Physical Meaning

“…Note that Carnot erroneously assumed that the same caloric (heat) passes through the engine and extracts (produces) work by lowering its temperature, similar to how the same water flow passes through the water-wheel and produces work by lowering its elevation potential. This error, considering the knowledge at the time, in no way diminishes Carnot's ingenious reasoning and conclusions about limiting, reversible processes and its accurate limitations of heat to work conversion [5].…”

“…This simple, thermodynamic temperature scale happened to be the same as the absolute temperature scale obtained using an ideal gas thermometer with constant specific heat [5].…”

“…The consequence of a process and cycle reversibility is most ingenious and far-reaching, see elsewhere [5]. Carnot's simple and logical reasoning that mechanical work is extracted in heat engine due to the caloric (heat) passing from high to low temperature, led him to a very logical conclusion that any heat transfer from higher to lower temperature (like in a heat exchanger), without extracting possible work (like in a reversible heat engine), will be an irreversible loss of work potential [4,5].…”

“…Actually, the "Carnot Ratio Equality" is probably the most important equation in Thermodynamics and among the most important equations in natural sciences. Carnot's ingenious reasoning opened the way to the generalization of Thermodynamic reversibility and energy process-equivalency, definition of absolute thermodynamic temperature, and a new thermodynamic material property "Entropy", as well as the Gibbs Free Energy, one of the most important Thermodynamic functions for the characterization of electro-chemical systems and their equilibriums, thus resulting in the formulation of the universal and far-reaching Second Law of thermodynamics [5,6].…”

“…Carnot's simple and logical reasoning that mechanical work is extracted in heat engine due to the caloric (heat) passing from high to low temperature, led him to a very logical conclusion that any heat transfer from higher to lower temperature (like in a heat exchanger), without extracting possible work (like in a reversible heat engine), will be an irreversible loss of work potential [4,5]. Then he expended his logical reasoning to conclude that all reversible (ideal) heat engines, working between the same heat reservoirs, must have equal and maximum possible efficiency.…”