1900 | Quantum theory proposed / Planck |
1901 | Discovery of human blood groups / Landsteiner |
1905 | Wave-particle duality of light / Einstein |
1905 | Special theory of relativity / Einstein |
1906 | Existence of vitamins proposed / Hopkins |
1906 | Evidence that Earth has a core / Oldham |
1908 | Synthesis of ammonia from its elements / Haber |
1909 | Idea of genetic disease introduced / Garrod |
1909 | Boundary between Earth's crust and mantle identified / Mohorovicic |
1909 | Discovery of Burgess Shale: ancient invertebrate fossils / Walcott |
1910 | First mapping of a gene to a chromosome / Morgan and others |
1911 | Discovery of the atomic nucleus / Rutherford |
1911 | Superconductivity discovered / Onnes |
1912 | Discovery of cosmic rays / Hess |
1912 | Idea of continental drift presented / Wegener |
1914 | First steps in elucidating chemical transmission of nerve impulses: neurotransmitters / Dale; Barger; Loewi |
1914 | Astronomical theory of climate change / Milankovitch |
1915 | General theory of relativity / Einstein |
1918 onward | Synthesis of genetics with the theory of evolution by natural selection (neodarwinism) / Fisher; Haldane; Wright |
1921 | Isolation of insulin / Banting & Best |
1923 | Nature of galaxies discovered / Hubble |
1925 | Description of Australopithecus africanus / Dart |
1925-26 | Matrix and wave formulations of quantum mechanics / Heisenberg; Schrödinger |
1927 | Matter is proved to be wavelike / Davisson & Germer |
1928 | Discovery of penicillin / Fleming |
1929 | Expansion of the Universe established / Hubble |
1929 | First suggestion that Earth's magnetic field reverses / Matuyama |
1930 | First absolute geological timescale / Holmes |
1930s | Theory of chemical bonds developed / Pauling |
1930s onward | Establishment of the scientific study of animal behavior / von Frisch; Lorenz; Tinbergen |
1931 | Birth of radioastronomy / Jansky |
1931 | First electron microscope / Ruska |
1932 | Discovery of the neutron / Chadwick |
1932 | Discovery of the positron, first antimatter particle / Anderson |
1935 | Magnitude scale for earthquakes / Richter |
1935 | Theory of the nuclear force / Yukawa |
1937 | Discovery of the citric acid cycle / Krebs |
1938 | Nuclear reactions in stars / Bethe; von Weizsäcker |
1938 | First observation of superfluidity / Kapitza |
1939 | Discovery of nuclear fission / Meitner & Frisch |
1943 | Mutations in bacteria identified / Luria & Delbrück |
1944 | Evidence in bacteria that DNA is the genetic material / Avery, MacLeod, and McCarty |
1944 | Start of Mexican wheat improvement program, leading to the "green revolution" / Borlaug |
1945 | Formulation of the one-gene, one-enzyme hypothesis / Beadle & Tatum |
1946 | Radiocarbon dating / Libby |
1946 | Initial elucidation of the reactions involved in photosynthesis / Calvin |
1947 | Invention of the transistor / Shockley, Bardeen, and Brattain |
1948 | Big Bang theory for origin of the Universe / Gamow, Alpher, and Herman |
1948 | Quantum electrodynamics / Feynman; Schwinger; Tomonaga |
1949 | Immunological tolerance hypothesis proposed / Burnet |
1951 | Presentation of the idea of gene transposition: "jumping genes" / McClintock |
1952 | First polio vaccine / Salk |
1952 | Theory of nerve-cell excitation announced / Hodgkin & Huxley |
1953 | Production of amino acids in "early Earth" conditions / Miller & Urey |
1953 | First determination of the amino-acid sequence of a protein / Sanger et al. |
1953 | Structure of DNA: the double helix / Watson & Crick |
1956 | Discovery of the neutrino / Cowan & Reines |
1957 | Superconductivity explained / Bardeen, Cooper, and Schrieffer |
1958 | Quantum tunneling of electrons in semiconductors / Esaki |
1958 | First three-dimensional protein structure published / Kendrew et al. |
1960 | First laser / Maiman |
1960 onward | Discoveries of fossils of early Homo in East Africa / Leakeys and others |
1961 | Nature of the genetic / triplet code proposed / Crick et al. |
1963 | Deterministic chaos: the butterfly effect / Lorenz |
1963 | Discovery of quasars / Schmidt |
1963 | Explanation for magnetic stripes on the sea floor: seafloor spreading / Vine & Matthews |
1964 | Existence of quarks proposed / Gell-Mann; Zweig |
1964 | Genetic explanations proposed for animal social behavior / Hamilton |
1965 | Discovery of cosmic microwave background radiation / Penzias & Wilson |
1967 | First warning of an anthropogenic "greenhouse effect" / Manabe & Wetherald |
1967 | Theory of plate tectonics / McKenzie & Parker; Morgan |
1967 | Electroweak theory, first unification of fundamental forces / Weinberg; Glashow; Salam |
1967 | Proposal that certain cell organelles are descended from free-living bacteria / Margulis |
1968 | Pulsars discovered / Hewish et al. |
1968 | Theory of random molecular evolution / the neutral theory proposed / Kimura |
1970 | Reverse transcriptase discovered / Baltimore; Temin & Mizutani |
1973 | Gamma-ray bursts from outer space / Klebesadel, Strong, and Olsen |
1973 | Advent of genetic engineering techniques / Cohen, Boyer, and Berg |
1973 | Invention of magnetic resonance imaging / Lauterbur |
1974 | Identification of CFCs as threat to ozone layer / Molina & Rowland |
1974 | Principles of cell-mediated immunity unveiled / Zinkernagel & Doherty |
1974 | Discovery of "Lucy," Australopithecus afarensis / Johanson & Taieb |
1974 | First Grand Unified Theory of particle physics / Georgi & Glashow |
1975 | Monoclonal antibodies created / Köhler & Milstein |
1976 | Patch-clamp technique for studying single ion channels / Neher & Sakmann |
1977 | First complete DNA sequence of an organism / Sanger et al. |
1977 | Discovery of deep-sea hydrothermal vents / Corliss et al. |
1978 | Observation of astronomical dark matter / Rubin |
1980 | Unveiling of genetic controls on animal body-plan development / Nüsslein-Volhard & Wieschaus |
1980 | First human oncogene / "cancer gene" identified / Weinberg |
1980 | Impact hypothesis for extinctions at the Cretaceous/Tertiary boundary / Alvarez et al. |
1981 | Superstring theory / Green & Schwarz |
1982 | Prion hypothesis proposed / Prusiner |
1983 | AIDS virus identified / Barré-Sinoussi et al. |
1985 | Genetic fingerprinting invented / Jeffreys |
1985 | Ozone hole discovered / Farman et al. |
1985 | Discovery of buckminsterfullerene / Kroto et al. |
1986 | First high-temperature superconductor / Bednorz & Müller |
1987 | Formulation of the "Out of Africa" hypothesis of human evolution using molecular data / Cann, Stoneking, and Wilson |
1995 | Bose-Einstein condensation of trapped atoms / Cornell & Wieman |
1995 | First extrasolar planet identified / Mayor & Queloz |
1997 | Dolly the sheep created by cloning / Wilmut et al. |
2001 | Publication of near-complete sequences of the human genome / International Human Genome Sequencing Consortium; Venter et al. |