In science, the naming of a new branch of thermodynamics often results in a variety of near-synonymous names, particularly if approached in the typical haphazard, trial-and-error, type of naming process. Often is the case that names emerge unknowingly in text, for many years, before the subject begins to solidify, settling on the either the most used name or the one with the most intuitive sense.

Three system perspectives
The issue surrounding naming choice of subjects dealing with thermodynamics applications, generally, has to do with the fact that thermodynamics can be applied and used according to the three points of view by which the system and the system boundary can be defined: (a) processes occurring inside the body, (b) processes viewed external to the body, (c) processes of a system of interacting bodies (of types (a) and (b) subsumed).

To give an example of this, American physical chemist Alfred Lotka, in his 1925 Elements of Physical Biology, in application of physics and thermodynamics to the study of humans or, more generally, biological structures, devotes a portion of his preface to explaining that, in his view, the ‘biophysics’ refers to the physics study of the individual, whereas ‘physical biology’ refers to the physics study of biological systems of individuals. The following is the key section by Lotka: [2]

“The term physical biology has been employed to denote the broad application of physical principles and methods in the contemplation of biological systems, whereas biophysics, in common parlance, relates rather to the special field of certain physical aspects of life processes of the individual. With this terminology, physical biology would comprehend biophysics within its scope.”

The definition of system, used by Lotka is that of the thermodynamic system, a subject of which Lotka spends considerable time on.

The issue becomes even more diverged than this, being that there are two ways one can attempt to study the individual: the internal perspective and the external perspective, the former representative of the thermodynamics of biochemical processes inside of the body, e.g. cellular, membrane, transport, etc., the latter representative of subjects such as psychodynamics or exercise physiology.

Naming rule-of-thumb
A good rule, in naming new branches of thermodynamics, is to follow the protocol used behind the logic of name “chemical thermodynamics”, where (a) the additive new subject (e.g. chemistry) is affixed with the appropriate suffix (e.g. -ary, -ical, –al, etc.) and (b) the new core subject is followed by the word “thermodynamics”. This simple rule often saves decades of thought as to naming choice. The emergence of the branch of thermodynamics called specifically “chemical thermodynamics”, for instance, is as follows: [1]

1876: On the Equilibrium of Heterogeneous Substances Willard Gibbs
1882: "The Thermodynamics of Chemical Operations" Hermann Helmholtz
1884: Studies in Chemical DynamicsJacobus van't Hoff
1903: Thermodynamics and Chemistry: A Non-mathematical Treatise for Chemists and Students of Chemistry Pierre Duhem
1907: Experimental and Theoretical Applications of Thermodynamics to Chemistry Walther Nernst
1912: A Text Book of Thermo-Chemistry and Thermodynamics Otto Sackur
1913: Text-book of Thermodynamics with special reference to Chemistry James Partington
1921: Thermodynamics and Chemistry Frank MacDougall
1923: Thermodynamics and the Free Energy of Chemical Substances Gilbert Lewis and Merle Randall
1924: Chemical Thermodynamics James Partington
1933: Modern Thermodynamics by the Method of Willard Gibbs Edward Guggenheim
1949: Thermodynamics: Advanced Treatment for Chemists and Physicists Edward Guggenheim
1950: Chemical Thermodynamics Ilya Prigogine and Raymond Dufay
1950: Chemical Thermodynamics Frederick Rossini
1950: Chemical Thermodynamics: Basic Theory and Methods Irving Klotz
1965: Chemical Thermodynamics John Kirkwood and Irwin Oppeheim

Thus, given the above rule, the subject of "thermodynamics and chemistry" (1880s) became "chemical thermodynamics" (1920s) over a period of forty years. Hence, if one is to learn by example, in the naming of a new branch of thermodynamics, e.g. "the thermodynamics of surface interactions", one should skip to the chase (e.g. surface thermodynamics), and save years of thought on questions regarding name choice.

On this basis, for example, one might ask: how should the subject of sociology and thermodynamics be named? Possible naming examples might include some that have been used and other not yet used: social thermodynamics (1972), socio-thermodynamics (2002), sociology thermodynamics, sociodynamics (1990s), etc. Using the above rule, the correct name, in the future, should result to be: sociological thermodynamics.

Biochemical thermodynamics (rule-of-thumb correct name) biochemistry + thermodynamics
Synonyms: bioenergetics, bio-thermodynamics, biothermodynamics, biological thermodynamics, etc.

Geochemical thermodynamics (rule-of-thumb correct name) = geochemistry + thermodynamics
Synonyms: thermodynamics for geologists (1967), thermodynamics in Geochemistry (1993), etc.

Other examples
On this naming logic, the subject of the use of thermodynamics in information theory should correctly be called "information theory thermodynamics"; although the term "information thermodynamics" is a weaker alternative, that has been used in the past.

In other cases, to note, the above rule of thumb does not always work. The example of neurothermodynamics or neurological thermodynamics (brain-systems studies) vs. neurochemical thermodynamics (neurochemical operations studies) is one such case. In the case of the study of the thermodynamic aspects of psychology, the name “psychodynamics” as persevered, whereas the rule-of-thumb correct name psychological thermodynamics is non-existent.

The subject of the study of “thermodynamic and evolution” seems to logically be called “evolutionary thermodynamics” modeled on the new field of evolutionary psychology; whereas a weaker variant could be "evolution thermodynamics".

In some cases, at present, historical presidence seems to hold weight in naming use. The example of psychodynamics, the subject of the use of the first and second laws of thermodynamics, in the study of the psyche, should correctly be called "psychological thermodynamics", the rule-of-thumb correct name, a combination of psychology + thermodynamics, but it is not. The word seems to have roots in the 1860 term "psychophysics" used by German physicist and psychologist Gustav Fechner. Other synonyms include: psycho-dynamics, dynamic view or "mental dynamics (Freud, 1923), psychic energism and dynamism (Jung, 1928), the psychical energy model (Bowlby, 1969), "dynamic psychology", or energy psychology

1. De Donder, T. (1936). Thermodynamic Theory of Affinity: A Book of Principles, (pg. xvii). Oxford: Oxford University Press.
2. Lotka, Alfred J. (1925). Elements of Physical Biology. Williams & Wilkins Co.

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