Timeline of thermodynamics

A timeline of events related to thermodynamics, statistical mechanics, and random processes.

• c. 3000 BC - The ancients viewed heat as that related to fire. The ancient Egyptians viewed heat as related to origin mythologies. One example, is the theory of the Ogdoad, or the “primordial forces”, from which all was formed. These were the elements of chaos, numbered in eight, that existed before the creation of the sun.^[1]
• c. 500 BC - Heraclitus became famous as the "flux and fire" philosopher for his proverbial utterance: "All things are flowing." Heraclitus argued that the three principal elements in nature were fire, earth, and water. Of these three, however, fire is assigned as the central element controlling and modifying the other two. The universe was postulated to be in a continuous state of flux or permanent condition of change as a result of transformations of fire. Heraclitus summarized his philosophy as: "All things are an exchange for fire." In 460 BC, Hippocrates postulated that: "Heat, a quantity which functions to animate, derives from an internal fire located in the left ventricle."
• c. 485 BC - Parmenides makes the ontological argument against nothingness, essentially denying the possible existence of a void.
• c. 460 BC - Leucippus, in opposition to Parmenides' denial of the void, proposes the atomic theory, which supposes that everything in the universe is either atoms or voids; a theory which, according to Aristotle, was stimulated into conception so to purposely contradict Parmenides' argument.
• c. 350 BC - Aristotle proclaims, in opposition to Leucippus, the dictum horror vacui or “nature abhors a vacuum”. Aristotle reasoned that in a complete vacuum, infinite speed would be possible because motion would encounter no resistance. Since he did not accept the possibility of infinite speed, he decided that a vacuum was equally impossible.

Atomic postulates

• 5th century BC – the classical elements are used to support various theories of combustion; Empedocles writes about his four-element theory of earth, water, air, and fire
• 5th century BC – Leucippus and Democritus formulate the philosophy of atomism
• 1st century BC – Lucretius writes his epic atomistic poem De Rerum Natura
• Several arguments are proposed supporting Aristotle's arguments for the impossibility of a void including, Plato, Al-Farabi (Alpharabius) and others, but was criticized by Leucippus, Hero of Alexandria, Ibn al-Haytham and others.

• 1000s – Avicenna invents the refrigerated coil, which condenses aromatic vapours, in order to produce essential oils through steam distillation.^[2][3][4]
• 1000s – Avicenna gauged the relative "coldness" or "hotness" of air, using a rudimentary air thermometer (or thermoscope),^[5][6] similar in design to an earlier device which could expand and contract the air constructed by Philo of Byzantium and Hero of Alexandria.
• 1500s-1600s – Cornelius Drebbel, Robert Fludd, Galileo Galilei and Santorio Santorio were able to gauge the relative "coldness" or "hotness" of air, using an air thermometer (or thermoscope), likely influenced by an earlier device which could expand and contract the air constructed by Philo of Byzantium and Hero of Alexandria.
• 1600 – Francis Bacon surmised: "Heat itself, its essence and quiddity is motion and nothing else."
• 1620 – Francis Bacon reviews a wide range of observations about heat and related phenomena, and suggests that heat is related to motion (Novum Organum, Book II, XI)
• 1643 – Galileo Galilei, while generally accepting the horror vacui of Aristotle, believes that nature’s vacuum-abhorrence is limited. Pumps operating in mines had already proven that nature would only fill a vacuum with water up to a height of 30 feet. Knowing this curious fact, Galileo encourages his former pupil Evangelista Torricelli to investigate these supposed limitations and in doing so invented the first vacuum and mercury thermometer.
• 1650 – Otto von Guericke builds the first vacuum pump
• 1660 – Robert Boyle experimentally discovers Boyle's Law, relating the pressure and volume of a gas
• 1665 – Robert Hooke stated: "Heat being nothing else but a very brisk and vehement agitation of the parts of a body."
• 1669 – J.J. Becher puts forward a theory of combustion involving combustible earth (Latin terra pinguis).
• 1676–1689 – Gottfried Leibniz develops the concept of vis viva, a limited version of the conservation of energy
• 1694–1734 – Georg Ernst Stahl names Becher's combustible earth as phlogiston and develops the theory
• 1702 – Guillaume Amontons introduces the concept of absolute zero, based on observations of gases
• 1738 – Daniel Bernoulli publishes Hydrodynamics, initiating the kinetic theory
• 1761 – Joseph Black discovers that ice absorbs heat without changing its temperature when melting
• 1772 – Black's student Daniel Rutherford discovers nitrogen, which he calls phlogisticated air, and together they explain the results in terms of the phlogiston theory
• 1776 – John Smeaton publishes a paper on experiments related to power, work, momentum, and kinetic energy, supporting the conservation of energy
• 1777 – Carl Wilhelm Scheele distinguishes heat transfer by thermal radiation from that by convection and conduction
• 1783 – Antoine Lavoisier discovers oxygen and develops an explanation for combustion; in his paper "Réflexions sur le phlogistique", he deprecates the phlogiston theory and proposes a caloric theory
• 1784 – Jan Ingenhousz describes Brownian motion of charcoal particles on water
• 1791 – Pierre Prévost shows that all bodies radiate heat, no matter how hot or cold they are
• 1798 – Count Rumford (Benjamin Thompson) performs measurements of the frictional heat generated in boring cannons and develops the idea that heat is a form of kinetic energy; his measurements refute caloric theory, but are imprecise enough to leave room for doubt

• 1804 – Sir John Leslie observes that a matte black surface radiates heat more effectively than a polished surface, suggesting the importance of black body radiation
• 1805 – William Hyde Wollaston defends the conservation of energy in On the Force of Percussion
• 1808 – John Dalton defends caloric theory in A New System of Chemistry and describes how it combines with matter, especially gases; he proposes that the heat capacity of gases varies inversely with atomic weight
• 1810 – Sir John Leslie freezes water to ice artificially
• 1813 – Peter Ewart supports the idea of the conservation of energy in his paper On the measure of moving force; the paper strongly influences Dalton and his pupil, James Joule
• 1819 – Pierre Louis Dulong and Alexis Thérèse Petit give the Dulong-Petit law for the specific heat capacity of a crystal
• 1820 – John Herapath develops some ideas in the kinetic theory of gases but mistakenly associates temperature with molecular momentum rather than kinetic energy; his work receives little attention other than from Joule
• 1822 – Joseph Fourier formally introduces the use of dimensions for physical quantities in his Theorie Analytique de la Chaleur
• 1822 – Marc Séguin writes to John Herschel supporting the conservation of energy and kinetic theory
• 1824 – Sadi Carnot analyzes the efficiency of steam engines using caloric theory; he develops the notion of a reversible process and, in postulating that no such thing exists in nature, lays the foundation for the second law of thermodynamics, and initiating the science of thermodynamics
• 1827 – Robert Brown discovers the Brownian motion of pollen and dye particles in water
• 1831 – Macedonio Melloni demonstrates that black body radiation can be reflected, refracted, and polarised in the same way as light
• 1834 – Émile Clapeyron popularises Carnot's work through a graphical and analytic formulation
• 1841 – Julius Robert von Mayer, an amateur scientist, writes a paper on the conservation of energy, but his lack of academic training leads to its rejection
• 1842 – Mayer makes a connection between work, heat, and the human metabolism based on his observations of blood made while a ship's surgeon; he calculates the mechanical equivalent of heat
• 1842 – William Robert Grove demonstrates the thermal dissociation of molecules into their constituent atoms, by showing that steam can be disassociated into oxygen and hydrogen, and the process reversed
• 1843 – John James Waterston fully expounds the kinetic theory of gases, but is ridiculed and ignored
• 1843 – James Joule experimentally finds the mechanical equivalent of heat
• 1846 – Karl-Hermann Knoblauch publishes De calore radiante disquisitiones experimentis quibusdam novis illustratae
• 1846 – Grove publishes an account of the general theory of the conservation of energy in On The Correlation of Physical Forces
• 1847 – Hermann von Helmholtz publishes a definitive statement of the conservation of energy, the first law of thermodynamics

• 1848 – William Thomson extends the concept of absolute zero from gases to all substances
• 1849 – William John Macquorn Rankine calculates the correct relationship between saturated vapour pressure and temperature using his hypothesis of molecular vortices
• 1850 – Rankine uses his vortex theory to establish accurate relationships between the temperature, pressure, and density of gases, and expressions for the latent heat of evaporation of a liquid; he accurately predicts the surprising fact that the apparent specific heat of saturated steam will be negative.
• 1850 – Rudolf Clausius gives the first clear joint statement of the first and second law of thermodynamics, abandoning the caloric theory, but preserving Carnot's principle.
• 1851 – Thomson gives an alternative statement of the second law.
• 1852 – Joule and Thomson demonstrate that a rapidly expanding gas cools, later named the Joule–Thomson effect or Joule–Kelvin effect
• 1854 – Helmholtz puts forward the idea of the heat death of the universe
• 1854 – Clausius establishes the importance of dQ/T (Clausius's theorem), but does not yet name the quantity.
• 1854 – Rankine introduces his thermodynamic function, later identified as entropy
• 1856 – August Krönig publishes an account of the kinetic theory of gases, probably after reading Waterston's work
• 1857 – Clausius gives a modern and compelling account of the kinetic theory of gases in his On the nature of motion called heat
• 1859 – James Clerk Maxwell discovers the distribution law of molecular velocities
• 1859 – Gustav Kirchhoff shows that energy emission from a black body is a function of only temperature and frequency
• 1865 – Clausius introduces the modern macroscopic concept of entropy
• 1865 – Josef Loschmidt applies Maxwell's theory to estimate the number-density of molecules in gases, given observed gas viscosities.
• 1867 – Maxwell asks whether Maxwell's demon could reverse irreversible processes
• 1870 – Clausius proves the scalar virial theorem
• 1872 – Ludwig Boltzmann states the Boltzmann equation for the temporal development of distribution functions in phase space, and publishes his H-theorem
• 1874 – Thomson formally states the second law of thermodynamics.
• 1876 – Josiah Willard Gibbs publishes the first of two papers (the second appears in 1878) which discuss phase equilibria, statistical ensembles, the free energy as the driving force behind chemical reactions, and chemical thermodynamics in general.
• 1876 – Loschmidt criticises Boltzmann's H theorem as being incompatible with microscopic reversibility (Loschmidt's paradox).
• 1877 – Boltzmann states the relationship between entropy and probability.
• 1879 – Jožef Stefan observes that the total radiant flux from a blackbody is proportional to the fourth power of its temperature and states the Stefan–Boltzmann law.
• 1884 – Boltzmann derives the Stefan–Boltzmann blackbody radiant flux law from thermodynamic considerations.
• 1888 – Henri-Louis Le Chatelier states his principle that the response of a chemical system perturbed from equilibrium will be to counteract the perturbation.
• 1889 – Walther Nernst relates the voltage of electrochemical cells to their chemical thermodynamics via the Nernst equation.
• 1889 – Svante Arrhenius introduces the idea of activation energy for chemical reactions, giving the Arrhenius equation.
• 1893 – Wilhelm Wien discovers the displacement law for a blackbody's maximum specific intensity.

• 1900 – Max Planck suggests that light may be emitted in discrete frequencies, giving his law of black-body radiation
• 1905 – Albert Einstein argues that the reality of quanta would explain the photoelectric effect
• 1905 – Einstein mathematically analyzes Brownian motion as a result of random molecular motion
• 1906 – Nernst presents a formulation of the third law of thermodynamics
• 1907 – Einstein uses quantum theory to estimate the heat capacity of an Einstein solid
• 1909 – Constantin Carathéodory develops an axiomatic system of thermodynamics
• 1910 – Einstein and Marian Smoluchowski find the Einstein–Smoluchowski formula for the attenuation coefficient due to density fluctuations in a gas
• 1911 – Paul Ehrenfest and Tatjana Ehrenfest–Afanassjewa publish their classical review on the statistical mechanics of Boltzmann, Begriffliche Grundlagen der statistischen Auffassung in der Mechanik
• 1912 – Peter Debye gives an improved heat capacity estimate by allowing low-frequency phonons
• 1916 – Sydney Chapman and David Enskog systematically develop the kinetic theory of gases.
• 1916 – Einstein considers the thermodynamics of atomic spectral lines and predicts stimulated emission
• 1919 – James Jeans discovers that the dynamical constants of motion determine the distribution function for a system of particles
• 1920 – Megh Nad Saha states his ionization equation
• 1923 – Debye and Erich Huckel publish a statistical treatment of the dissociation of electrolytes
• 1924 – Satyendra Nath Bose introduces Bose–Einstein statistics, in a paper translated by Einstein
• 1926 – Enrico Fermi and Paul Dirac introduce Fermi–Dirac statistics for fermions
• 1927 – John von Neumann introduces the density matrix representation and establishes quantum statistical mechanics
• 1928 – John B. Johnson discovers Johnson noise in a resistor
• 1928 – Harry Nyquist derives the fluctuation-dissipation relationship for a resistor to explain Johnson noise
• 1929 – Lars Onsager derives the Onsager reciprocal relations
• 1942 – Joseph Leo Doob states his theorem on Gauss–Markov processes
• 1944 – Lars Onsager gives an analytic solution to the 2D Ising model including its phase transition

• 1948 – Claude Elwood Shannon establishes information theory.
• 1957 – Aleksandr Solomonovich Kompaneets derives his Compton scattering Fokker–Planck equation.
• 1957 – Ryogo Kubo derives the first of the Green-Kubo relations for linear transport coefficients.
• 1957 – Edwin T. Jaynes gives MaxEnt interpretation of thermodynamics from information theory.
• 1972 – Jacob Bekenstein suggests that black holes have an entropy proportional to their surface area.
• 1974 – Stephen Hawking predicts that black holes will radiate particles with a black-body spectrum which can cause black hole evaporation

• History of physics
• History of thermodynamics
• Timeline of information theory
• List of notable textbooks in statistical mechanics
• Physics
• Thermodynamics
• Parmenides influence on the development of thermodynamics