In human thermodynamics, Charles Galton Darwin (1887-1962), or C.G. Darwin, was an English physicist and grandson of Charles Darwin, notable, through the publication of his 1952 book The Next Million Years, conceived of people as "human molecules" and coined the term "human thermodynamics". [1] Specifically, after defining people to be molecules, he then grandly states: [2]

“Through determining some kind of laws of human thermodynamics, we shall be more successful in doing good in the world.”

In short, Darwin argued that in order to logically predict human history, one would first need to define the person as a point molecule and to model human social systems as "conservative dynamical systems" such that when human molecules collide there exists a conservative nature to the interaction and that both internal and external parameters must be accounted for in a statistical thermodynamic analysis of any human system. [2] Darwin spent the last 15 years of his life musing over these ideas.

This same logic, with the exception of the use of chemical thermodynamics (more correct for human social systems) verses statistical thermodynamics (less correct for human social systems), and terminology, i.e. "human molecule" and "human thermodynamics", was developed independently by American chemical engineer Libb Thims between 1995 to 2005. [1] C.G. Darwin also was the first to postulate the existence of a set of "laws of human thermodynamics". [2]

C.G. Darwin, in this light, was one of the founders of "history thermodynamics", the thermodynamic study of human history.

Education
Darwin was educated at Cambridge at Trinity College where he graduated from in 1910 with a degree in mathematics. Following this, he did post-graduate work at the Victoria University of Manchester, working under Ernest Rutherford and Niels Bohr. In 1912, his interests developed into using his mathematical skills assisting Henry Moseley on X-ray diffraction of crystals using Rutherford's atomic theory. Later he would spend one year working at the California Institute of Technology. On the outbreak of World War I, he joined the Royal Engineers, where he worked on problems in ballistics, and later served in the Royal Flying Corps.

Thermodynamics
Following World War I, from 1919 to 1922, he was fellow and lecturer at Christ's College, Cambridge, where he and Ralph Fowler, the founder of the zeroth law of thermodynamics, developed new methods of statistical mechanics, i.e. the Darwin-Fowler method, that later served as a foundation for quantum statistics.

Later years
In 1924, he became a Tait professor of natural philosophy at the University of Edinburgh, where he worked on quantum optics and magneto-optic effects. He also anticipated some of P.A.M. Dirac's relativistic theory of the electron. He was a professor at Edinburgh from 1924 to 1936 and master of Christ's College from 1936, and directed the National Physical Laboratory during World War II, leaving the post in 1949. The last 15 years of his life were devoted to the study of the sociological implications of the population explosion, as reflected in his book The Next Million Years (1952).

References
1. (a) Thims, Libb. (2008). The Human Molecule, (preview). Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume One), (preview). Morrisville, NC: LuLu.
(c) Thims, Libb. (2007). Human Chemistry (Volume Two). Morrisville, NC: LuLu.
2. Darwin, Charles G. (1952). The Next Million Years (pg. 26), (Scribd) (Google Books). London: Rupert Hart-Davis.

Further reading
● Charles Galton Darwin - The Columbia Encyclopedia, Sixth Edition 2007.
● Charles Galton Darwin – GaltonInstitute.org