1612 
Sancorius Sanctorius's
Commentariar in artem medicinalem Galeni makes mention of Galileo's
thermoscope, the forerunner to the thermometer. 
1620 
Johannes van Helmont
defines "gas" (the Flemish word for chaos) for airlike substances. 
1638 
Galileo
Galilei (15641642) points out that simple pumps can only raise water
about 32 feet, though this had been common knowledge to pump makers of
the time. 
1641 
Ferdinand II, Grand
Duke of Tuscany, invents a thermometer using liquid in a glass tube with
one end sealed, a slight improvement to Galileo's thermoscope. 
1643 
Evangelista
Torricelli (16081647) invents the barometer, also producing the first
partial vacuum. 
1647 
Gilles
Personne de Roberval (16021675) performed an oftquoted experiment
on air pressure whereby a carp's swimbladder is partially removed, squeezed
of almost all air and tied shut. The carp is then placed in a Torricellian
vacuum and the bladder is then observed to expand. 
1648 
Florin Perrier experimentally
shows that the height achieved by mercury in a barometer decreased as one
scaled a mountain, a theoretical prediction of his brotherinlaw, Blaise
Pascal, and also known as the Puy de Dôme experiment. 
1651 
Jean Pecquet's (16221674)
book on psychology popularizes the Roberval experiment (English translation
in 1653). He also introduces the term "elater" as the tendency of air to
expand, and theorizes that air on the earth's surface is compressed by
the weight of the atmospheric air. 
1654 
Otto
von Guericke's (160286) experiment with two iron hemispheres held
together by a strong partial vacuum being strong enough to resist the pull
of a train of horses on either side.
Ferdinand II invents the sealed thermometer. 
1660 
Robert
Boyle (162791) publishes New Experiments PhysioMechanicall, touching
the Spring of the Air, and its Effects, One experiment clearly shows
the dependency on Torricelli's vacuum on ambient air pressure. Also presented
are discussions of both Pecquet's idea of
air modelled by coiledup woollike or springlike atoms (which was preferred
by Boyle) and of Descarte's idea of whirling particles which repell one
another at short distances.
In response to Boyle's
ideas, Franciscus Linus proposes a theory
whereby a vacuum is explained by the creation of an invisible collection
of threadlike "funniculus," which strive to hold nearby objects together.
Richard Townley and Henry
Power's experiments establishing the PV law for expansion (the socalled
"Boyle's Law" or "Marriotte's Law"). 
1661 
Boyle
adds an appendix to his 1660 work, responding to the criticisms of Linus
and Thomas Hobbes, presenting improved experimental
results and giving a version of what is now known as "Boyle's Law" for
the case of compression. 
1662 
Boyle's
"Defense of the Doctrine touching the Spring and Weight of the Air." 
1663 
Blaise
Pascal (16231662) writes On the Equilibrium of Liquids (published
posthumously) suggesting that pressure is transmitted equally in all directions
in a fluid (later known as Pascal's Law), probably discovered around 1648.
Henry Power's book Experimental Philosophy,
publishing early results on the PV law. 
1669 
Johann Joachim Becher's
Subterranean Physics, a tract on alchemy and experimental results
on minerals, introduces the idea that a "terra pingus" (oily earth) causes
fire. This idea is later picked up to the form flogiston theory of heat. 
1670 
Boyle
discovers that when acid interacts with certain metals a flammable gas
is produced, known now as Hydrogen. 
1673 
Christiaan
Huygens (162995) builds a motor driven by the explosion of gunpowder. 
1674 
John Mayow suggests
that air may consist of two different gases from experiments done on mice
and candles, reported in his Five MedicoPhysical Treatises. 
1676 
Edmé Mariotte
independently finds relationship between pressure and volume, in his work
On the Nature of Air. (Known as Mariotte's Law in France, and Boyle's
Law elsewhere.) 
1685 
Mariotte's The Motion
of Water and Other Fluids published (posthumously). 
1690 
Denis
Papin (16471712) uses steam pressure to move a piston for the first
time. 
1697 
Georg Ernts Stahl introduces
the idea of phlogiston as the agent of burning and rusting. 
1702 
Guillaume Amontons extrapolates
the idea of absolute zero from the observation that equal drops in temperature
produce equal drops in pressure, and since pressure cannot become negative,
there must be a lower limit to temperature. 
1705 
Francis Hauksbee shows
that sound needs air for propagation. 
1712 
Thomas Newcomen's steam
engine. 
1714 
Gabriel Fahrenheit's
mercury thermometer. 
1723 
Stahl's Foundations
of Dogmatic and Experimental Chemistry popularizes phlogiston and the
ideas of Johann Becher. 
1724 
Hermann Boerhaave proposes
that heat is a fluid of some sort. 
1730 
Johann Juncker's Conspectus
of Chemistry systematically expands phlogiston theory. 
1738 
Daniel
Bernoulli (17001782), in a treatise on hydrodynamics, gives a derivation
of the gas laws from a billiard ball model, derives the BoyleMariotte
relation and used conservation of mechanical energy to show that as temperature
changes the pressure will change proportionally to the square of the particle
velocities. The paper is all but forgotten until 1859. 
1739 
George Martine establishes
that the volume of an object is not proportional to the amount of heat
it have. 
1744 
Mikhail Vasilievich Lomonossov
publishes a paper on the causes of heat and cold, stating that heat is
a form of motion. 
1748 
Lomonosov formulates
the laws of conservation of energy and mass. 
1756 
William Cullen's An
Essay on the Cold Produced by Evaporating Fluids and some Other Means of
Producing Cold. 
1761 
Joseph Black uses melting
ice to discover latent heat. 
1765 
James Watt invents his
steam engine, which is over six times for effective than Newcomen's. 
1772 
Johan Carl Wilcke calculates
the latent heat of ice. 
1781 
Wilcke comes up with
the concept of specific heats. 
1782 
Lavoisier establishes
an early version of the conservation of matter through his finding of constancy
of weight before and after chemical reactions. 
1783 
Lavoisier's work, Reflections
on Phlogiston, on the weaknesses of phlogiston theory with respect
to combustion. 
1786 
Lavoisier and Laplace's
work Memoir on Heat. 
1787 
JackuesAlexandre Charles
determines that at a given temperature change, different gases expand the
same amount (known as Charles's Law). 
1789 
Lavoisier's book Elementary
Treatise on Chemistry, containing the law of mass conservation. 
1791 
Richard Kirwan, previously
a staunch defender of phlogiston theory, concedes that the experimental
evidence says otherwise.
Pierre Prévost's theory of heat
and radiation exchange, stating that cold is the absence of heat, hot bodies
radiate continually and that a lack of radiation indicates equilibrium
with surroundings temperature.
Jeremias Richter founds stoichiometry,
the principle of fixed chemical reactions. 
1798 
Cannonboring experiments of Benjamin
Thompson (Count Rumford) (17531814) demonstrating the conversion of
work into heat in his work Enquiry Concerning the Source of Heat which
is Excited by Friction, showing also that additional weight of an object
due to heating (a prediction of caloric theory) was not detected. 
1799 
Icerubbing experiments of Humphrey
Davy (17781829) demonstrating the conversion of work into heat,
and suggesting that an indefinite amount of heat could be generated from
a body (whereas caloric theory severely limits its available amount).
JosephLouis Proust formulates that elements
in a compound always combin in definite mass ratios (Proust's Law). 
1800 
William Herschel publishes
"An investigation of the powers of prismatic colours to heat and illuminate
objects" investigating the effects of different wavelengths of light on
a thermometer, finding light just beyond the red to be the hottest. 
1801 
Johann Ritter discovers
ultraviolet radiation while doing work with silver chloride.
John Dalton finds that two gases in the
same region produce the same pressure as if they occupied the region alone,
known as the law of partial pressures. 
1802 
JosephLouis GayLussac
finds that, at a given pressure, the change in volume is proportional to
the change in temperature. 
1803 
John Dalton formulates
his atomic theory of matter, stating that chemicals are formed by integer
numbers of atoms, by studying the weights of chemicals and reactants.
ClaudeLouis Berthollet demonstrates that
reaction rates depend on both the amount of substances present as well
as their affinities in his work Essay on Static Chemistry.
William Henry finds that a gas's mass when
dissolved in a liquid is proportional to the pressure (later known as Henry's
law). 
1804 
John
Leslie (17661832) writes An Experimental Inquiry into the Nature
and Propagation of Heat, showing that light and radiated heat have
similar properties. 
1805 
PierreSimon
Laplace (17491827) formulates his theory of capillary forces based
on his studies of molecular forces in liquids. 
1806 
Thomas Young formulates
the physical concept of energy.
Thomas Thomson's System of Chemistry
contains the first published account of Dalton's
ideas on atomic theory. 
1807 
Jean
Baptiste Joseph Fourier (17681830) publishes his On the Propagation
of Heat in Solid Bodies, introducing many mathematical novelties, including
his series expansion techniques. 
1808 
(Dec 31st) GayLussac
states that gases chemically combine in exact proportions of volume. 
1811 
SiméonDenis
Poisson (17811840) develops his mathematical theory of heat, based
on the work of Fourier.
Amedeo Avogadro formulates that all gases
of a given volume have the same number of molecules, regardless of pressure
or temperature (Avogadro's law).
Jöns Jakob Berzelius states that electrical
and chemical forces are one and the same and that atoms are electrically
charged, in his work Theory of Chemical Proportions and the Chemical
Action of Electricity. 
1812 
Davy writes Elements
of Chemical Philosophy, including a hypothesis that in addition to
the vibrational and undulatory motion of solids, gasses as well exhibit
rotational motion about an axis.
Delaroche and Bérard's
measurements of specific heats at atmospheric pressure of a large number
of gasses. Their measurements agreed with Laplace's
predictions and remained a cornerstone for caloric theory. 
1819 
PierreLouis Dulong
and Aléxis
Thérèse Petit (17911820) find constant specific heat
at constant pressure for metals over wide range of temperatures, finding
that the product of the specific heat and the atomic mass remains constant
(known as the Law of Dulong and Petit). 
1821 
John Herapath publishes
an account of the kinetic theory of gas in the Philosophical Transactions
of the Royal Society (after being rejected the year before), influencing
Joule's ideas.
Thomas Johann Seebeck discovers a process
by which heat is converted into electricity in the junction of some metals,
known as theormoelectricity. 
1822 
Charles Cagniard de la Tour,
in liquification experiments, finds that both temperature and pressure
must be appropriately controlled, and discovers what is now know as the
critical point of a substance. 
1824 
Sadi
Carnot (17961832) publishes "Reflections on the Motive Power of Fire,"
introducing the ideal gas cycle analysis, showing that when heat passes
between two bodies theormodynamic work (which he defines) is done, and
proposes an idea for an internal combustion engine.
PierreSimon
Laplace (17491827) publishes several papers refining an idea of Newton's
that gasses are formed through repulsive interactions. 
1827 
Robert Brown discovers
and studies, using a microscope, tiny particles suspended in liquid which
are seen to be in constant motion. 
1829 
GustaveGaspard Coriolis
defines the term "kinetic energy" in his studies published as On the
Calculation of Mechanical Action.
Thomas Graham experimentally uncovers the
law of gas diffusion, by which the rate of a gas's diffusion, squared,
is proportional to its density. 
1833 
Heinrich Friedrich Emil Lenz
determines that resistence in metals increases with temperature. 
1834 
Clapeyron formulates
the first version of the second law of thermodynimcs, based on studies
of steam engines.
JeanCharlesAthanase Peltier shows that
heat can be absorbed or given off when current is passed one way or the
other across a junction between two different metals (knows as the Peltier
effect). 
1837 
von Suerman's experiments
on air at reduced pressures verifying Clappeyron's
version of Carnot's formulas. 
1842 
R.J. Mayer becomes the
first to clearly formulate the conservation of energy, and that heat is
a form of (mechanical) energy.
William
Thomson (Lord Kelvin)'s (18241907) On the Uniform Motion of Heat
in Homogeneous Solid Bodies. 
1843 
(through 1848) Through a series of experiments, James
Prescott Joule (18181889) establishes the exact relationship between
heat and mechanical work.
John James Waterston anonymously publishes
Thoughts on the Mental Functions containing in a note at the end
a full and accurate account of the kinetic theory of gases. The work goes
all but completely unread. 
1845 
Waterston submits a
papers on the kinetic theory of gases to the Royal Society, who rejects
it. The paper precisely lays out the ideas of energy equipartition and
introduced the notion of the mean free path. A short abstract appears in
another journal, but the work is ignored. 
1847 
Joule
publishes "On Matter, Living Force, and Heat" in the Manchester Courier,
stating the principle of the conservation of energy and giving the conversion
from heat to kinetic energy.
Hermann
Ludwig Ferdinand von Helmholtz (182194) publishes his On the Conservation
of Energy. (Independently of Joule's publications.)
John William Draper finds that all substances
begin to glow around 525°C, starting in the red and eventually becoming
white. 
1848 
Joule
reads a paper using Herapath's kinetic theory.
The paper contains the first numerical results from the kinetic theory.
(Not published until 1851, and not well known until Clausius's
reference to it in 1857.) 
1849 
James Thomson, using
Carnot's theories, predicts the lower of the
freezing point of water under high pressures.
Kelvin,
in speaking of Carnot's theory, coins the
term "thermodynamics." 
1850 
Rudolf
Clausius (182288) gives a verbal formulation of the second law, for
which there is no mechanism whose only function is the transfer of heat. 
1851 
Kelvin
independently rediscovers the idea of absolute zero (149 years after Amontons),
extrapolating from Charles' law that it must be about 273°C, and suggesting
that the energy of the molecules would tend to zero. He also derives the
second law of thermodynamics using Carnot's
ideas. 
1852 
HenriVictor Regnault
shows that gas behavior doesn't quite follow Boyle's law at low temperatures
and extrapolates a value of 273°C for absolute zero.
Joule
and Kelvin
shows that expanding gases become cooler in the process. 
1854 
Hendrik Roozeboom experimentally
determines the phase law, later derived mathematically by Gibbs. 
1856 
Karl Krönig (182279)
writes a paper suggesting that gas molecules in equilibrium travel in straight
lines until they collide with something, published in Poggendorfs Annalen
der Physik. 
1857 
Clausius
publishes a paper on a mathematical kinetic theory, explaining evaporation
and establishing heat as energy distributed statistically among particles. 
1858 
Clausius
introduces the idea of the mean free path of a particle in working out
a kinetic theory of diffusion. 
1859 
James
Clerk Maxwell (183179) reads a paper on kinetic theory, printed in
1860 as "Illustrations of the Dynamical Theory of Gases," using random
velocity distributions for gases, and showing viscosity to be independent
of temperature.
Gustav
Robert Kirchhoff (18241887) derives from the second law of thermodynamics
that objects cannot be distinguished by their thermal radiation at a given
uniform temperature, one must also use reflected light.
Bernoulli's
paper republished due to renewed interest in kinetic theory. (Herapath
henceforth goes into obscurity.) 
1860 
Michael Faraday's paper
"Pressure Melting Effect" describing the lowering of the freezing point
of water using pressure. 
1861 
Thomas Andrew, in a
series of experiments with CO 2 through 1869, finds
that at low temperatures Boyle's law breaks down, and there are regions
on a PV chart where, for a given isotherm, changes in volume produce no
change in pressure. This region is recognized to be the liquidvapour equilibrial
state. He rigorously finds the critical point and triple point. 
1863 
John Tyndall's Heat
as a mode of Motion, popularizing Maxwell's
ideas on heat. 
1865 
Clausius
uses Carnot's
techniques to derive entropy (and shows the two laws of thermodynamics
expressible in the same ways as the older caloric theory). 
1871 
Maxwell
comes up with his parabol of the daemon to conceptually explain heat statistics. 
1872 
Ludwig
Boltzmann's (18441906) derives his HTheorem,
showing explicitly that isolated systems must always evolve in such a way
that entropy increases. (He introduces a number of mathematical innovations,
including a of technique of discretizing the allowed energy levels for
a molecule, and allowing this energy bin to go to zero.) The paper meets
with widespread opposition. 
1873 
Josiah
Willard Gibbs (18391903) publishes Graphical Methods in the Thermodynimcs
of Fluids and A Method of Geometrical Representation of the Thermodynamic
Properties of Substances by Means of Surfaces.
Van der Waals creates theory for the liquid
to gas transition. 
1876 
Gibbs
publishes the first part of On the Equilibrium of Heterogeneous Substances
(the 2nd part in 1878).
Josef Loschmidt's (182195) "reversibility
paradox" formulated, pointing out the irreversibility of Boltzmann's
kinetic theory despite the underlying classical laws of physics remaining
timeinvariant.
(Karl Paul Gottfried von Linde builds the
first practical refrigerator using liquid ammonia.) 
1877 
Boltzmann
formulates a statistical mechanical version of the second law of thermodynamics
in the paper, "On the Relation Between the Second Law of the Mechanical
Theory of Heat and the Probability Calculus with Respect to the Theorems
on Thermal Equilibrium". There he formulates that the entropy of a system
is proportional to the log of the phase space volume occupied by the macrostate
of the system, S = k ln O, making use
of his mathematical innovation of using finite areas of phase space.
Liquification of oxygen achieved, after nearly one hundred years of
trying, by Cailletet (on Dec 2nd) and Raoul
Pictet (on Dec 22nd). 
1879 
Josef
Stephan (18351893) determines that the amount of radiation given off
by a body through heating is proportional to the fourth power of its temperature
(known as the StephanBoltzmann law), RT = sT^4. 
1884 
Boltzmann
(18441906) succeeds in theoretically deriving the radiation law found
by Stephan.
Gibbs
coins the term "statistical mechanics" for the kinetic theory's treatment
of thermodynamic issues. 
1893 
Wilhelm
Carl Werner Otto Fritz Franz Wien (18641928) experimentally finds
that the wavelength of maximum radiation of thermal body is proportional
to the inverse of its temperature (known as Wien's law) using an oven with
a small hole as an approximation to a theoretical blackbody. 
1895 
Pierre Curie shows that
magnets loses their magnetic properties as their temperature is increases,
eventually losing it completely above a certain temperature for that material
(knows as the Curie point). 
1896 
Ernst Zermelo's (18711953)
recurrence paradox formulated. 
1899 
Lummar and Alfred
Pringsheim complete the first accurate measurements of the spectral
radiancy of blackbodies, sharply contrasting the prediction made by the
RayleighJeans radiation law (the socalled "ultraviolet catastrophe").
Emile Hilaire Amagat publishes The Laws
of Gases of extensive experiments with gases under very high pressures. 
1900 
Max
Karl Ernst Ludwig Planck (18581947), studying blackbody radiation
and following Boltzmann's
techniques of dividing the energy continuum into cells, proposes fixing
cell sizes to be proportional to oscillator frequency, and in so doing
derives the correct radiation spectrum for blackbodies. Planck proposes
the constant, h (Planck's constant), as a quantum of action in phase
space. (Though the derivation is technically only valid for hn
<< kT it stands until corrected by Einstein
in 1909. In 1908, derivations appear in Planck's work involving an assumption
of energy quantization.) 
1902 
Gibbs
publishes Elementary Principles in Statistical Mechanics, his treatise
on the subject. 
1905 
Marian von Smoluchowski
and Albert
Einstein (18791955) independently investigate Brownian motion, convincing
many of the atomic hypothesis. 
1906 
Walther Nernst formulates
his "heat theorem," stating that in the limit of absolute zero temperature,
both the entropy change and the heat capacity go to zero (subsequently
recognized as the Third law of thermodynamics).
Weiss creates general theory of paramagnetic
to ferromagnetic transitions. 
1907 
Andrei
Andreyevich Markov (18561922) develops his theory of linked probabilities.
Pierre Weiss explains ferromagnetism by
way of small domains of magnetic polarization within a material. 
1908 
JeanBaptiste Perrin
calculates the approximate size of a water molecule using early work on
Brownian motion. 
1909 
Constantin
Carathéodory publishes a purely mathematical and axiomatic account
of thermodynamics. 
1911 
Planck's
first paper explicitly quantizing the allowed radiation of oscillators
in a blackbody.
Otto Sackur suggests at the Solvay Conference
that phase space be divided into cells of volume h^3.
Ladislaw Natanson proposes that Planck's
law is the result of the indistinguishability of states of light quanta.
Niels
Henrik David Bohr (18851962) begins constructing atomic models which
try to forge a connection with Planck's constant as a fundamental constant
of quantization.
Heike Kamerlingh Onnes experimentally finds
that mercury will become superconductive when cooled very close to absolute
zero. 
1912 
Otto Sackur and H
Tetrode independently solve Boltzmann's Law to obtain
S = Nk ln[ (2pmkT)^(3/2) V / N h^3 ] + (5/2)
Nk 
showing the need for quantization in classical gas laws. 
1916 
Robert Andrews Millikan,
in experiments with the photoelectric effect, both confirms the theoretical
work of Einstein
and confirms the value of Planck's constant independent of work done with
blackbodies. 
1922 
Louis
Victor Pierre Raymond duc de Broglie (18921987) applies Sackur's
technique of quantizing phase space to derive the Wien distribution law
for energy density:
du = (8ph/c^3) exp(hn/kT)
n^3 dn 
Charles Darwin and Ralph
Fowler publish a work on methods of evaluating statistical probabilities. 
1923 
Gilbert N Lewis's Thermodynamics
and the Free Energy of Chemical Substances, bringing thermodynamics
in closer contact with chemistry. 
1924 
(June) Satyendranath
Bose (18941974) sends Einstein
a copy of his paper, containing a new derivation of Planck's radiation
law based purely on photon statistics, after it was rejected by Philosophical
Magazine. Einstein
translates it into German and submits it to the Zeitschrift für
Physik for him with a recommendation.
Einstein
presents a paper showing that in the limit of high temperatures, a gas
of indistinguishable Bose particles approaches the characteristics of a
Boltzmann gas.
de Broglie writes two papers in the Comptes
rendus of the Paris Academy elaborating on a fundamental principle
of waveparticle duality. The works mature into his 1925 doctoral thesis. 
1925 
Max
Born (18821970), Werner
Karl Heisenberg (19011976), and Pascual Jordan
formulate quantum mechanics based on the mathematics of matrix algebra.
Einstein,
citing works by Bose
and de
Broglie, suggests that the analogy between quantum gases and molecular
gases are complete, and that both photons and molecules have both particle
and wave characteristics. He also points out that molecules at low temperatures
cannot be considered independent entities, even in the absence of intermolecular
forces.
Samuel Goudsmit hypothesis an extra degree
of freedom to electrons termed "spin" due to the mathematical similarity
to classical spin. Later, with George
Eugene Uhlenbeck (19001988), halfinteger quantum numbers are introduced
in the theory of the hydrogen atom.
Wolfgang
Pauli (19001958) formulates the exclusion principle for the electron,
accounting for a number of chemical properties in atoms and molecules.
Planck
devises a new derivation of thermodynamic formulas for Boltzmann gases
using the formulations,
z = exp(e/kT) , Z = z^N / N! 

1926 
Born
introduces into quantum mechanics his probability interpretation of interactions.
Enrico Fermi derives the statistical properties
of gases which obey the Pauli exclusion principle.
Erwin
Rudolf Josef Alexander Schrödinger (18871961) developes a second
formulation of quantum theory in terms of wave mechanics independently.
Paul
Adrien Maurice Dirac (19021984) relates the symmetry of quantum mechanical
wave functions to the statistics of Bose,
Einstein
and Fermi. He also derives the Planck distribution
from first principles.
Arthur
Stanley Eddington's (18821944) The Internal Constitution of the
Stars, relating the radiation pressure of stars to their luminosity.
Robert Hutchings Goddard launches the first
rocket, using liquid fuel and reaching a height of 184 feet and 60 miles
per hour. 
1927 
John
von Neumann (19031957) formulates a fully quantum mechanical generalization
of statistical mechanics.
Bohr
pronounces his notion of complimentarity in quantum theory.
Heisenberg
formulates the uncertainty principle of quantum mechanics. 
1928 
Arnold
Sommerfeld (18681951) treats electrons in metals as a degenerate Fermi
gas using the new techniques of quantum theory.
Dirac
comes up with a relativistic quantum mechanical wave equation for the electron. 
1930 
Discover of the lambda point of helium at which it
becomes a superfluid (sonamed in 1941) at 2.2°K. 
1931 
George
David Birkhoff (18841944) proves the general ergodic theoreom. 
1934 
Bragg and Williams
formulates an Ising model for paramagnetic to ferromagnetic transitions. 
1935 
William Francis Giauque
achieves a temperature of only 0.1°K for helium using a magnetic trap
to slow the motion of the molecules.
Lev
Davidovich Landau (19081968) publishes his phenomenological meanfield
treatment for phase transitions. 
1937 
Peter Leonidovich Kapitza
theoretically explains superfluidity in helium. 
1938 
Claude
Elwood Shannon (1916) publishes A Symbolic Analysis of Relay and
Switching Circuits, instigating the study of information theory and
giving a systematic way of mathematically treating noise. 
1939 
W Conyer Herring calculates
bulk properties of materials from quantum principles, specifically explaining
how beryllium acts as a metal. 
1946 
N N Bogolyubov works
on a generalization of the Boltzmann equation, working from the timereversal
invariant Liouville equation, further clarifying the internal structure
of statistical mechanics. 
1948 
Shannon's
major publication on information theory and symbolic logic, A Mathematical
Theory of Communication. 
1955 
Erwin Wilhelm Mueller's
field ion microscope is the first instrument to allow imaging of individual
atoms. 
1958 
BJ Alder and T
Wainwright's experiments on low particle equilibrium distributions. 
1958 
BJ Alder and T
Wainwright discover vortex diffusion in liquids. 
1980 
Heinrich Rohrer and
Gerd Binnig develop the scanning tunnelling
microscope, allowing for imaging of atoms embedded on surfaces.
Klaus von Klitzing discovers the quantum
hall effect. 