Entropy models

In thermodynamics, entropy models are any of various verbal, visual, heuristic, or statistical teaching models used to describe the 1865 quantity 'entropy', defined in various ways by German physicist Rudolf Clausius during the years 1850 to 1875. Some of the various oft-cited entropy models are as follows:

Model

PictureNotes




Four element theory
Aristotle 75
Aristotle
350BC four elements (s) Denser elements tend to rise; lighter elements fall; earth is the heaviest element; fire the lightest.

“For any two portions of fire, small or great, will exhibit the same ratio of solid to void; but the upward movement of the greater is quicker than that of the less.”
Three principles
Geber 75
Geber
790Three principlesMetals are formed of two elements: sulphur, ‘the stone which burns’, the principle of combustibility, and mercury, the principle of metallic properties. Salt gives solidity.
Sulphur combustion model
Paracelsus 75
Paracelsus
1524Paracelsus combustion model
Terra pinguis model
Johann Becher 75
Johann Becher
1699Becher combustion model
Phlogiston model
Georg Stahl 75
Georg Stahl
1703Stahl combustion theory
Caloric model
Lavoisier 75
Antoine Lavoisier (1789)
1789Caloric theory model
Re-establishment of equilibrium in the caloric
Sadi Carnot 75
Sadi Carnot
1824re-estabishment of equilibrium in the caloricA Lavoisier-base view that heat consisted of indestructible caloric particles and that a body returned to its original position (state) at the end of one heat cycle.
Transformation content
Clausius (75px)
Rudolf Clausius
1850Joule experiment (1843)
Dissipation
(law of dissipation)
William Thomson 75
William Thomson
1852Dissipation
Disgregation
Clausius (75px)
Rudolf Clausius
1862Disgregation[3]
Entropy (melting ice)
Clausius (75px)
Rudolf Clausius
1862ice melting[1]

1870Pouring water into sea 300px“The second law of thermodynamics has the same degree of truth as the statement that if you throw a tumblerful into the sea, you cannot get the same tumblerful out again.”
— James Maxwell (1870), “Letter to John Strutt”, Dec 6; the “moral” of his Maxwell’s demon argument [21]
Velocity distribution model
(H-theorem)
Boltzmann 75 young
Ludwig Boltzmann
1872Maxwell Boltzmann distribution
Entropy of mixing
Gibbs (75px)
Willard Gibbs
1876Entropy of mixingNote: this could have been Gibbs' 1902 work; see: Gilbert Lewis' 1925 The Anatomy of Science (pg. 148).
Disorder
Helmholtz 75
Hermann Helmholtz
1882solid, liquid, gas
Ghostly quantity
John Perry 75
John Perry
1899Entropy ghost
S = k ln W
Planck 75
Max Planck
1901Multiplicity
Mixed-up-ness
Gibbs (75px)
Willard Gibbs
1903

Image needed
Note: ditto to previous note.
Elementary disorder
Planck 75
Max Planck
1906Adiabatic-demagnitization
Typing monkeys
Emile Borel 75
Emile Borel (1913)
1913Typing monkeys 250
Entropies of bodies
Lewis 75
Gilbert Lewis
1923Entropy of silver
Entropy (shuffling cards)
Lewis 75
Gilbert Lewis
Arthur Eddington
1925Ordered - Shuffled CardsSeems to have been first described in Lewis' The Anatomy of Science (1925); then expanded be Eddington in his The Nature of the Physical World (1928).

Arrow of time
Eddington 75
Arthur Eddington
1928arrows of time

Entropy (information)
Szilard 75
Leo Szilard (1929)
1929Szilard's demon

Information theory
Shannon 75
Claude Shannon
1948Hartley (voltage transmissions)Note: this has nothing to do with thermodynamics; contrary to popular opinion; but rather is a mis-informed urban myth existing in ignorant science.
Unscrambled eggs
(Broken eggs)
icon 75 (test)
Walter Albersheim?
1955Entropy (eggs)
Entropy (child’s playroom)
Landsberg 75
Peter Landsberg
1961Child's  playroom
Energy dispersal
Peter Atkins 75
Peter Atkins
1984Energy dispersial  (diagram)
(spreading out of energy)
Frank Lambert 75
Frank Lambert
1999Image needed
Entropy ≠ Disorder
In a view of entropy as "energy spreading out"; a misinformed view promoted by American organic chemist Frank Lambert; based on a reading of one of William Thomson's articles.

See also
Entropy formulations
Entropy (misinterpretations)

References
1. Sladek, John T. (1974). The New Apocrypha: a Guide to Strange Science and Occult Beliefs (pg. 258). Stein and Day.
2. Lindberg, David C., Porter, Roy, Jo Nye, Mary, and Numbers, Ronald. (2003). The Cambridge History of Science: the Modern Physical and Mathematical Sciences (pgs. 494-95). Cambridge University Press.
3. Disgregation – Wikipedia.

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