In economic thermodynamics, material entropy is an approximate term used to define the amount of entropy or order associated with a structure. The term was coined in 1966 by English-born American economist Kenneth Boulding and defined as “a measure of the uniformity of the distribution of elements and, more uncertainly, compounds and other structures on the earth’s surface.” [1] Material entropy, as generally found, is a spinoff term having little theoretical substance to it. Some will state, for instance, that “there is, fortunately, no law of increasing material entropy, as there is in the corresponding case of energy, as it is quite possible to concentrate diffused materials if energy inputs are allowed.” [2]

The general difficulty of using the concept of material entropy, beyond that involved in the formation of small molecules or small chemical systems, is that, in the words of Rudolf Clausius, “it is not possible to determine the whole energy of a body, but only the increase which the energy has received, whilst the body was passing into its present condition; and the same is also true of entropy”. [3] Shown adjacent, for instance, are various measures of entropies S° for different chemical species. In other words, the entropies of bodies, depend upon various factors involved related to the heats and energies released or absorbed during their formation, and are based on reference points. It is not simply a matter of assigning low entropy values to ordered structures, e.g. coal, and high entropy values to disordered structures, e.g. burned coal and waste gas.

History of missapplication
In the popular 1971 book The Entropy Law and the Economic Process, Romanian-born American mathematical economist Nicholas Georgescu-Roegen outlined a type of material entropy theory by stating that “entropy is an index of the relative amount of bound energy in an isolated structure or, more precisely, of how evenly the energy is distributed in such a structure”. In other words, he states, “high entropy means a structure in which most or all energy is bound, and low entropy, a structure in which the opposite is true”. These, in turn, stimulated American economist Jeremy Rifkin to state, in his 1980 book Entropy: A New World View, a supposed fourth law of thermodynamics: “in a closed system, the material entropy must ultimately reach a maximum”, which he translated into the postulate that humans are squandering the world's natural resources.

Objections
The use of material entropy, as seeded by Georgescu-Roegen and promulgated by Rifkin, is generally seen as point of non-logic. Israeli physical chemist Brian Silver, in commentary on what he calls “Georgescu-Roegen’s brainchild”, for instance, states that “the term material entropy is meaningless; it has not the slightest connection with entropy. [4] Likewise, American chemist Glen Gordon states that “in taking up entropy, Rifkin is like a child with a new toy—he has great fun applying the concepts to all aspects of our high-technology society.” [5]

In a recent 14-page article “The Three Laws of Thermodynamics”, in Redorbit News, a staff writer takes issue with Georgescu-Roegen's interpretation of the second law of thermodynamics (entropy law) and its relevance to the economics of production. The paper concurs with experts on thermodynamics that Georgescu-Roegen has committed a major error. Namely, Georgescu-Roegen's notion of "material entropy," which he christened as the "fourth law of thermodynamics," is unfounded. They conclude that Georgescu-Roegen's purported law, as the application of the second law to the realm of matter, is a grave conceptual blunder. [6]

References
1. Boulding, Kenneth E. (1966). Environmental Quality in a Growing Economy. John Hopkins Press.
2. Lippit, Victor D. (1995). Radical Political Economy: Explorations in Alternative Economic Analysis, (pg. 360). M.E. Sharpe.
3. Clausius, Rudolf. (1879). The Mechanical Theory of Heat, (chapter IX: "Determination of Energy and Entropy", pg. 196). London: Macmillan & Co. (second edition).
4. Silver, Brian L. (1998). The Ascent of Science, (pg. 231). Oxford University Press.
5. Gordon, Glen E. (1981). “Thermodynamics and Society” (review of Rifkin’s Entropy: A New World Order), Science, Vol. 211, March. 1340-41.
6. Staff Writer. (2004). “The Three Laws of Thermodynamics and the Theory of Production”, RedOrbit News, March 13.