• ------Maxwell theorizes that light and electromagnetism have the same source
  • 1869 --- Mendeleyev formulates the periodic table of the elements
  • 1873 --- van der Waals understands intermolecular forces
  • 1878 --- Kuhne coins term enzyme
  • 1879 --- Stefan understands thermal radiation
  • 1883 --- Reynolds defines his number
  • ------Thomson (Lord Kelvin) publishes about the size of atoms
  • 1887 --- Hertz observes the photoelectric effect
  • 1888 --- Hertz and Lodge independently prove that light and radio are the same phenomena
  • 1891 --- Eotvos shows equality of gravitational and inertial mass
  • 1895 --- Lorentz discovers his force
  • ------Rontgen discovers x-rays
  • 1896 --- Becquerel discovers rays which will be called radioactivity
  • 1897 --- Braun invents the oscilloscope
  • ------Rutherford separates alpha and beta rays
  • ------Thomson discovers the electron
  • 1898 --- Benda discovers mitochondria
  • 1900 --- Planck formulates quantum theory
  • ------Richardson discovers electron emission
  • ------Villard discovers gamma rays
  • 1901 --- Curie measures heat equivalent of radioactivity
  • 1903 --- Einthoven invents the EKG
  • 1905 --- Einstein formulates photon theory of light and Special Theory of Relativity
  • ------Hertzsprung relates stellar luminosity to spectra
  • 1906 --- Nernst understands absolute zero
  • 1907 --- Boltwood invents radioactive dating
  • 1908 --- Perrin calculates the size of an atom
  • 1911 --- Milliken measures elementary charge (electron q)
  • ------Rutherford's scattering experiments lead to his theory of atomic structure
  • 1912 --- Laue discovers x-ray diffraction
  • 1913 --- Bohr Theory of the atom
  • ------Russel develops theory of stellar evolution
  • 1914 --- Adams discovers white dwarf stars
  • ------Hertzsprung identifies main sequence stars
  • ------Rutherford suggests that H nucleus is fundamental "proton"
  • 1915 --- Einstein formulates the General Theory of Relativity
  • 1916 --- Schwarzschild theorizes black holes
  • 1918 --- Secchi defines stellar spectral classes
  • 1919 --- Aston builds mass spectrograph and discovers isotopes
  • ------Rutherford discovers nuclear reactions
  • 1921 --- Stern and Gerlach discover spin
  • 1923 --- Compton identifies his wavelength
  • ------Svedberg invents the ultracentrifuge
  • 1924 --- de Broglie publishes his wave theory of matter
  • 1925 --- Pauli introduces the exclusion principle
  • 1926 --- Fermi links spin with statistics
  • 1927 --- Thomson observes electron diffraction
  • 1928 --- Hartree develops his approximation
  • ------London and Heitler apply quantum mechanics to chemical bonds
  • 1930 --- Dirac theorizes antimatter
  • 1931 --- Fermi theorizes the neutrino
  • 1932 --- Anderson discovers the positron
  • ------Chadwick discovers the neutron
  • ------Ruska builds first electron microscope
  • 1934 --- Fermi theorizes weak interactions
  • ------Zwicky theorizes neutron stars
  • 1935 --- Yukawa theorizes strong interactions
  • 1937 --- Rabi does first NMR experiments
  • ------Tiselius invents electrophoresis
  • 1938 --- Bethe understands solar fusion
  • ------Krebs dscovers the TCA cycle
  • 1939 --- Hahn and Strassman and Meitner observe fission
  • 1940 --- McMillan and Abelson manufacture first artificial element
  • ---Fermi and Szillard prevail upon Einstein to convince Roosevelt of Nazi Atomic intentions. Manhattan project under direction of Robert Oppenheimer and Groves
  • 1941 --- Lipmann understands high energy phosphates (ie., ATP)
  • 1946 --- Bloch and Purcell make NMR practical as an observational instrument
  • ------First electronic computer built at PennsylvaniaUniversity
  • 1947 --- Libby does first carbon-14 dating
  • 1948 --- Feynman develops QED (with Schwinger and Tomonaga)
  • 1951 --- Hodgkin and Huxley and Katz work on transmission of nerve impulses
  • 1952 --- First use of isotopes in medicine
  • ------First artificial fusion reaction (after Teller denounced Opie) (U.S. Hydrogen bomb at Eniwetok Atoll)
  • ------Franklin studies DNA with x-ray diffraction
  • ------Sanger understands (first) protein structure
  • 1953 --- Watson and Crick and Rosalind Franklin discover stucture of DNA
  • 1956 --- Lee and Yang understand parity violation
  • ------Neutrino discovered at Los Alamos
  • 1957 --- Calvin discovers his cycle
  • ------Esaki discovers tunneling in diodes
  • 1960 --- First laser constructed by Maiman
  • 1961 --- Gell-man and Ne'emen theorize quarks
  • 1964 --- Fitch and Cronin do experiments leading to CPT theorem
  • 1968 --- Development of Electroweak Model by Glashow, Salam and Weinberg
  • 1972 --- Gell-man theorizes QCD (Quantum ChromoDynamics, about strong force)
  • 1973 --- Gross, Politzer and Wilczek theorize asymptotic freedom
  • 1974 --- First experimental evidence of quarks
  • 1980 --- First Personal Computers
  • 1983 --- W & Z bosons first observed
  • 1988 --- First release of Mathematica
  • 1994 --- Hubble Space Telescope confirms existance of black holes
  • 1995 --- Top quark discovered