In c.485 BC, Parmenides makes the ontological argument against nothingness, essentially denying the possible existence of a void.
In 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.
In 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.
In 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.
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 first philosophy of atomism
1st century BC - Lucretius writes his epic atomistic poem De Rerum Natura
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)
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
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 molecularmomentum 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
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 - 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
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