1749 – Émilie du Châtelet, in her French translation and commentary on Newton's Philosophiae Naturalis Principia Mathematica, derives the conservation of energy from the first principles of Newtonian mechanics.
1761 – Joseph Black discovers that ice absorbs heat without changing its temperature when melting
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
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 boringcannons and develops the idea that heat is a form of kinetic energy; his measurements are inconsistent with caloric theory, but are also sufficiently imprecise as to leave room for doubt.
1800–1847
1802 – Joseph Louis Gay-Lussac publishes Charles's law, discovered (but unpublished) by Jacques Charles around 1787; this shows the dependency between temperature and volume. Gay-Lussac also formulates the law relating temperature with pressure (the pressure law, or Gay-Lussac's law)
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
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 Théorie Analytique de la Chaleur
1822 – Marc Seguin 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. He also combined Boyle's Law, Charles's Law, and Gay-Lussac's Law to produce a Combined Gas Law. PV/T = k
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
1845 – Henri Victor Regnault added Avogadro's Law to the Combined Gas Law to produce the Ideal Gas Law. PV = nRT
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
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
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
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
1938 – Anatoly Vlasov proposes the Vlasov equation for a correct dynamical description of ensembles of particles with collective long range interaction.
1939 – Nikolay Krylov and Nikolay Bogolyubov give the first consistent microscopic derivation of the Fokker-Planck equation in the single scheme of classical and quantum mechanics.
1945–1946 – Nikolay Bogoliubov develops a general method for a microscopic derivation of kinetic equations for classical statistical systems using BBGKY hierarchy
1947 – Nikolay Bogoliubov and Kirill Gurov extend this method for a microscopic derivation of kinetic equations for quantum statistical systems
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.
1960–1965 – Dmitry Zubarev develops the method of non-equilibrium statistical operator, which becomes a classical tool in the statistical theory of non-equilibrium processes
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
1977 – Ilya Prigogine wins the Nobel prize for his work on dissipative structures in thermodynamic systems far from equilibrium. The importation and dissipation of energy could reverse the 2nd law of thermodynamics