In thermodynamics, principle of elementary disorder, “elementary disorder hypothesis” or “Boltzmann’s order-disorder principle” (Schrodinger, 1944), states that actual order-disorder positional and vibrational micro-states achievable by the atoms and molecules of physical systems, correspondent to the macro-state satisfaction of the second law of thermodynamics, in that "the principle of the growth of entropy will be satisfied in every direction". [1][5]
Overview
The principle of elementary disorder, according to American mechanical engineer Joseph Klein (1910), was introduced by German physicist Max Planck, beginning in about 1899, based on the macro-state conception of molar-order and molar-disorder of Austrian physicist Ludwig Boltzmann, as found in his 1896 Lectures on Gas Theory. [2]
In 1900, the term "principle of disorder" is first used by Planck. [3] In 1901, Planck gave the following outline his elementary disorder principle, in relation to the radiation energy emitted by the energy elements of a black body: [4]
“Entropy depends on disorder and this disorder, according to the electromagnetic theory of radiation for the monochromatic vibrations of a resonator when situated in a permanent stationary radiation field, depends on the irregularity with which it constantly changes its amplitude and phase, provided one considers time intervals large compared to the time of one vibration but small compared to the duration of a measurement. If amplitude and phase both remained absolutely constant, which means completely homogeneous vibrations, no entropy could exist and the vibrational energy would have to be completely free to be converted into work.”
The principle was given great emphasis by Planck in his 1906 Warmestrahlung (Heat Radiation) and in other writings on irreversibility up until 1914.
References
1. Planck, Max. (c.1914). The Theory of Heat Radiation, (pg. xvii). Springer (reprint).
2. Klein, Joseph F. (1910). Physical Significance of Entropy: of the Second Law (pgs. 5-10). D. Van Nostrand Co.
3. (a) Planck, Max. (1900). “Entropy and Temperature of Radiant Heat.” (Entropie und Temperatur Strahlender Warme), Annalen der Physik, vol. 1. no 4. April, pg. 719-37.
(b) Garola, Claudio and Rossi, Arcangelo. (2000). The Foundations of Quantum Mechanics: Historical Analysis and Open Questions: Lecce, Italy, 13-16 October 1998, (term: “elementary disorder hypothesis”, pgs. 88-95). World Scientific.
4. Planck, Max. (1901). "On the Law of Distribution of Energy in the Normal Spectrum". Annalen der Physik, vol. 4, p. 553 ff.
5. Schrödinger, Erwin. (1944). What is Life? (ch. 6 “Order, Disorder, and Entropy”, pgs. 67-75, esp. 74). Cambridge: Cambridge University Press.
