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Timeline of quantum mechanics, molecular physics, atomic physics, nuclear physics, and particle physics

Timeline of quantum mechanics, molecular physics[?], atomic physics, nuclear physics, and particle physics

440 BC Democritus speculates about fundamental indivisible particles---calls them "atoms"
1766 Henry Cavendish discovers and studies hydrogen
1778 Carl Scheele and Antoine Lavoisier discover that air is composed mostly of nitrogen and oxygen
1781 Joseph Priestley creates water by igniting hydrogen and oxygen
1800 William Nicholson[?] and Anthony Carlisle[?] use electrolysis to separate water into hydrogen and oxygen
1803 John Dalton introduces atomic ideas into chemistry and states that matter is composed of atoms of different weights
1811 Amedeo Avogadro claims that equal volumes of gases should contain equal numbers of molecules
1832 Michael Faraday states his laws of electrolysis
1871 Dmitri Ivanovich Mendeleev systematically examines the periodic table and predicts the existence of gallium, scandium, and germanium
1873 Johannes van der Waals[?] introduces the idea of weak attractive forces between molecules
1885 Johann Balmer[?] finds a mathematical expression for observed hydrogen line[?] wavelengths
1887 Heinrich Hertz discovers the photoelectric effect
1894 Lord Rayleigh and William Ramsay discover argon by spectroscopically analyzing the gas left over after nitrogen and oxygen are removed from air
1895 William Ramsay discovers terrestrial helium by spectroscopically analyzing gas produced by decaying uranium
1896 Antoine Becquerel[?] discovers the radioactivity of uranium
1896 Pieter Zeeman studies the splitting of sodium D lines[?] when sodium is held in a flame between strong magnetic poles
1897 Joseph Thomson[?] discovers the electron
1898 William Ramsay and Morris Travers[?] discover neon, krypton, and xenon
1898 Marie Curie and Pierre Curie isolate and study radium and polonium
1899 Ernest Rutherford discovers that uranium radiation is composed of positively charged alpha particles and negatively charged beta particles
1900 Paul Villard[?] discovers gamma-rays while studying uranium decay
1900 Johannes Rydberg refines the expression for observed hydrogen line wavelengths
1900 Max Planck states his quantum hypothesis[?] and blackbody radiation law
1902 Philipp Lenard[?] observes that maximum photoelectron energies are independent of illuminating intensity but depend on frequency
1902 Theodor Svedberg suggests that fluctuations in molecular bombardment cause the Brownian motion
1905 Albert Einstein explains the photoelectric effect
1906 Charles Barkla[?] discovers that each element has a characteristic X-ray and that the degree of penetration of these X-rays is related to the atomic weight of the element
1909 Hans Geiger and Ernest Marsden[?] discover large angle deflections of alpha particles by thin metal foils
1909 Ernest Rutherford and Thomas Royds[?] demonstrate that alpha particles are doubly ionized helium atoms
1911 Ernest Rutherford explains the Geiger-Marsden experiment[?] by invoking a nuclear atom model and derives the Rutherford[?] cross section
1912 Max von Laue[?] suggests using lattice solids to diffract X-rays
1912 Walter Friedrich[?] and Paul Knipping[?] diffract X-rays in zinc blende
1913 William Bragg[?] and Lawrence Bragg[?] work out the Bragg condition for strong X-ray reflection
1913 Henry Moseley shows that nuclear charge is the real basis for numbering the elements
1913 Niels Bohr presents his quantum model of the atom
1913 Robert Millikan measures the fundamental unit of electric charge
1913 Johannes Stark[?] demonstrates that strong electric fields will split the Balmer spectral line series of hydrogen
1914 James Franck[?] and Gustav Hertz[?] observe atomic excitation
1914 Ernest Rutherford suggests that the positively charged atomic nucleus contains protons
1915 Arnold Sommerfeld develops a modified Bohr atomic model with elliptic orbits to explain relativistic fine structure
1916 Gilbert Lewis[?] and Irving Langmuir formulate an electron shell model of chemical bonding
1917 Albert Einstein introduces the idea of stimulated radiation emission
1921 Alfred Lande[?] introduces the Lande g-factor[?]
1922 Arthur Compton[?] studies X-ray photon scattering by electrons
1922 Otto Stern[?] and Walter Gerlach[?] show "space quantization"
1923 Louis de Broglie suggests that electrons may have wavelike properties
1924 Wolfgang Pauli states the quantum exclusion principle[?]
1924 John Lennard-Jones proposes a semiempirical interatomic force law
1924 Satyendra Bose and Albert Einstein introduce Bose-Einstein statistics
1925 George Uhlenbeck[?] and Samuel Goudsmit[?] postulate electron spin
1925 Pierre Auger[?] discovers the Auger autoionization process
1925 Werner Heisenberg, Max Born, and Pascual Jordan[?] formulate quantum matrix mechanics[?]
1926 Erwin Schrödinger states his nonrelativistic quantum wave equation and formulates quantum wave mechanics
1926 Erwin Schrödinger proves that the wave and matrix formulations of quantum theory are mathematically equivalent
1926 Oskar Klein[?] and Walter Gordon[?] state their relativistic quantum wave equation
1926 Enrico Fermi discovers the spin-statistics[?] connection
1926 Paul Dirac introduces Fermi-Dirac statistics
1927 Clinton Davission[?], Lester Germer[?], and George Thomson[?] confirm the wavelike nature of electrons
1927 Werner Heisenberg states the quantum uncertainty principle
1927 Max Born interprets the probabilistic nature of wavefunctions
1928 Chandrasekhara Raman[?] studies optical photon scattering by electrons
1928 Paul Dirac states his relativistic electron quantum wave equation
1928 Charles G. Darwin[?] and Walter Gordon[?] solve the Dirac equation for a Coulomb potential
1929 Oskar Klein discovers the Klein paradox[?]
1929 Oskar Klein and Y. Nishina derive the Klein-Nishina cross section for high energy photon scattering by electrons
1929 N.F. Mott derives the Mott cross section for the Coulomb scattering of relativistic electrons
1930 Paul Dirac introduces electron hole theory
1930 Erwin Schrödinger predicts the zitterbewegung motion
1930 Fritz London[?] explains van der Waals forces as due to the interacting fluctuating dipole moments between molecules
1931 John Lennard-Jones proposes the Lennard-Jones interatomic potential
1931 Irene Joliot-Curie and Frédéric Joliot observe but misinterpret neutron scattering in paraffin
1931 Wolfgang Pauli puts forth the neutrino hypothesis to explain the apparent violation of energy conservation[?] in beta decay
1931 Linus Pauling discovers resonance bonding and uses it to explain the high stability of symmetric planar molecules
1931 Paul Dirac shows that charge conservation[?] can be explained if magnetic monopoles exist
1931 Harold Urey[?] discovers deuterium using evaporation concentration techniques and spectroscopy
1932 John Cockcroft[?] and Thomas Walton[?] split lithium and boron nuclei using proton bombardment
1932 James Chadwick discovers the neutron
1932 Werner Heisenberg presents the proton-neutron model of the nucleus and uses it to explain isotopes
1932 Carl Anderson[?] discovers the positron
1933 Max Delbruck suggests that quantum effects will cause photons to be scattered by an external electric field
1934 Irene Joliot-Curie and Frédéric Joliot bombard aluminum atoms with alpha particles to create artificially radioactive phosphorus-30
1934 Leo Szilard realizes that nuclear chain reactions may be possible
1934 Enrico Fermi formulates his theory of beta decay
1934 Lev Davidovich Landau tells Edward Teller that nonlinear molecules may have vibrational modes[?] which remove the degeneracy of an orbitally degenerate state
1934 Enrico Fermi suggests bombarding uranium atoms with neutrons to make a 93 proton element
1934 Pavel Alekseyevich Cherenkov reports that light is emitted by relativistic particles traveling in a nonscintillating liquid
1935 Hideki Yukawa presents a theory of strong interactions and predicts mesons
1935 Albert Einstein, Boris Podolsky[?], and Nathan Rosen[?] put forth the EPR paradox
1935 Niels Bohr presents his analysis of the EPR paradox
1936 Eugene Wigner develops the theory of neutron absorption by atomic nuclei
1936 Hans Jahn[?] and Edward Teller present their systematic study of the symmetry types for which the Jahn-Teller effect[?] is expected
1937 H. Hellmann finds the Hellmann-Feynman theorem[?]
1937 Seth Neddermeyer[?], Carl Anderson, J.C. Street, and E.C. Stevenson discover muons using cloud chamber[?] measurements of cosmic rays
1939 Richard Feynman finds the Hellmann-Feynman theorem
1939 Otto Hahn and Fritz Strassman[?] bombard uranium salts with thermal neutrons and discover barium among the reaction products
1939 Lise Meitner and Otto Frisch[?] determine that nuclear fission is taking place in the Hahn-Strassman experiments
1942 Enrico Fermi makes the first controlled nuclear chain reaction
1942 Ernst Stuckelberg[?] introduces the propagator to positron theory and interprets positrons as negative energy electrons moving backwards through spacetime
1943 Sin-Itiro Tomonaga publishes his paper on the basic physical principles of quantum electrodynamics
1947 Willis Lamb[?] and Robert Retheford[?] measure the Lamb-Retheford shift[?]
1947 Cecil Powell[?], C.M.G. Lattes, and G.P.S. Occhialini discover the pi-meson by studying cosmic ray tracks
1947 Richard Feynman presents his propagator approach to quantum electrodynamics[?]
1948 Hendrik Casimir[?] predicts a rudimentary attractive Casimir force on a parallel plate capacitor
1951 Martin Deutsch[?] discovers positronium
1952 David Bohm propose his interpretation of quantum mechanics
1953 R. Wilson observes Delbruck scattering[?] of 1.33 MeV gamma-rays by the electric fields of lead nuclei
1954 Chen Yang and Robert Mills[?] investigate a theory of hadronic[?] isospin[?] by demanding local gauge invariance[?] under isotopic spin[?] space rotations---first non-Abelian gauge theory[?]
1955 Owen Chamberlain[?], Emilio Segre[?], Clyde Wiegand[?], and Thomas Ypsilantis[?] discover the antiproton
1956 Frederick Reines and Clyde Cowan[?] detect antineutrinos[?]
1956 Chen Yang and Tsung Lee propose parity violation[?] by the weak nuclear force
1956 Chien Shiung Wu discovers parity violation by the weak force in decaying cobalt
1957 Gerhart Luders[?] proves the CPT theorem[?]
1957 Richard Feynman, Murray Gell-Mann, Robert Marshak[?], and Ennackel Sudarshan[?] propose a variational approximation (VA) Lagrangian for weak interactions
1958 Marcus Sparnaay[?] experimentally confirms the Casimir effect
1959 Yakir Aharonov[?] and David Bohm predict the Aharonov-Bohm effect[?]
1960 R.G. Chambers experimentally confirms the Aharonov-Bohm effect
1961 Murray Gell-Mann and Yuval Ne'eman discover the Eightfold Way patterns---SU(3)[?] group
1961 Jeffery Goldstone[?] considers the breaking of global phase symmetry
1962 Leon Lederman[?] shows that the electron neutrino is distinct from the muon neutrino
1963 Murray Gell-Mann and George Zweig[?] propose the quark/aces model
1964 Peter Higgs[?] considers the breaking of local phase symmetry
1964 John Stewart Bell shows that all local hidden variable theories must satisfy Bell's inequality
1964 Val Fitch[?] and James Cronin[?] observe CP violation by the weak force in the decay of K mesons
1967 Steven Weinberg puts forth his electroweak model of leptons
1969 J.C. Clauser, M. Horne, A. Shimony, and R. Holt propose a polarization correlation test of Bell's inequality
1970 Sheldon Glashow[?], John Iliopoulos[?], and Luciano Maiani[?] propose the charm quark
1971 Gerard 't Hooft[?] shows that the Glashow-Salam-Weinberg electroweak model can be renormalized
1972 S. Freedman and J.C. Clauser perform the first polarization correlation test of Bell's inequality
1973 David Politzer[?] proposes the asymptotic freedom of quarks
1974 Burton Richter[?] and Samuel Ting[?] discover the psi meson implying the existence of the charm quark
1975 Martin Perl[?] discovers the tauon[?]
1977 S.W. Herb finds the upsilon resonance implying the existence of the beauty quark
1982 A. Aspect, J. Dalibard, and G. Roger perform a polarization correlation test of Bell's inequality that rules out conspiratorial polarizer communication
1983 Carlo Rubbia, Simon van der Meer[?], and the CERN UA-1 collaboration find the W and Z intermediate vector bosons
1989 The Z intermediate vector boson resonance width indicates three quark-lepton generations

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