§ ii · dramatis personae
People
The pioneers who pulled the atom inside-out. Click any name for the full portrait, dates, contribution, and chapters in which they appear.
§ pre-xix
Before the long nineteenth
before 1801 · 1 figure
§ xix
The nineteenth century
1801 – 1900 · 19 figures
- Image: Wikimedia Commons · Public domain · Johann Jakob Balmer Johann Jakob Balmer 1825 – 1898 In 1885, found the formula for hydrogen's visible spectrum: pure pattern-matching, decades before anyone understood why. appears in balmers-ladder
- Image: Wikimedia Commons · Public domain · Unknown author August Kekulé 1829 – 1896 1865: proposed the ring structure of benzene. Founder of structural chemistry.
- Image: Wikimedia Commons · Public domain · Unknown author Edmond Laguerre 1834 – 1886 1879: introduced the polynomials that, decades later, would be the radial wavefunctions of the hydrogen atom.
- Image: Wikimedia Commons · Public domain · Not Mentioned J.J. Thomson 1856 – 1940 1897: discovered the electron in cathode rays. First subatomic particle. 1906 Nobel.
- Image: Wikimedia Commons · Public domain · Hugo Erfurth Max Planck 1858 – 1947 Introduced the quantum hypothesis in 1900, the foundational act of quantum mechanics. appears in plancks-catastrophe
- Image: Wikimedia Commons · Public domain · Bain News Service, publisher Restored by: Bammesk Ernest Rutherford 1871 – 1937 Discovered the atomic nucleus in 1911. Bohr's Manchester mentor; the 1911 gold-foil experiment that forced the nuclear atom is the experiment Bohr built his 1913 model on. appears in bohrs-leap
- Image: Wikimedia Commons · Public domain · Not mentioned Karl Schwarzschild 1873 – 1916 1915-1916: derived the first exact non-trivial solution of Einstein's field equations, describing the geometry around a non-rotating massive body. Foundation of black hole physics.
- Editorial placeholder · too.foo Albert Einstein 1879 – 1955 His 1905 paper on the photoelectric effect established the photon: light itself is quantized. appears in einsteins-photons
- Image: Wikimedia Commons · Public domain Max Born 1882 – 1970 1926: |ψ|² is a probability density. The Born rule, footnoted into the foundations of quantum mechanics.
- Image: Wikimedia Commons · Public domain · The American Institute of Physics credits the photo [1] to AB Lagrelius & Westphal , which is the Swedish company used by the Nobel Foundation for most photos of its book series Les Prix Nobel . Niels Bohr 1885 – 1962 1913: quantized angular momentum in the atom, explained Balmer's formula, founded the Copenhagen interpretation. appears in bohrs-leap
- Image: Wikimedia Commons · Public domain · Unknown author Erwin Schrödinger 1887 – 1961 1926: wrote down the equation iℏ∂ψ/∂t = Ĥψ that governs nonrelativistic quantum mechanics.
- Image: Wikimedia Commons · Public domain · Nobelprize.org Otto Stern 1888 – 1969 1922: with Gerlach, observed the discrete deflection of silver atoms in an inhomogeneous magnetic field. Established spin quantization.
- Editorial placeholder · too.foo Walther Gerlach 1889 – 1979 1922: ran the Stern-Gerlach experiment that proved spin is quantized.
- Image: Wikimedia Commons · Attribution · Los Alamos National Laboratory James Chadwick 1891 – 1974 1932: discovered the neutron. Manhattan Project British team leader. 1935 Nobel.
- Image: Wikimedia Commons · Public domain · Unknown author Louis de Broglie 1892 – 1987 Postulated that every particle of matter carries a wavelength λ = h/p, opening the door to wave mechanics. appears in de-broglies-wavelength
- Image: Wikimedia Commons · CC BY 3.0 · GFHund Friedrich Hund 1896 – 1997 1927: rule of maximum multiplicity for electron configurations. Foundational MO theory with Mulliken.
- Editorial placeholder · too.foo Douglas Hartree 1897 – 1958 1928: self-consistent-field method for atoms. Built mechanical differential analyzers for atomic calculations.
- Editorial placeholder · too.foo Vladimir Fock 1898 – 1974 1930: extended Hartree's method with antisymmetrization. Hartree-Fock theory.
- Image: Wikimedia Commons · Public domain · Nobel foundation Wolfgang Pauli 1900 – 1958 1925: the exclusion principle. 1927: the spinor formalism (Pauli matrices). 1930: postulated the neutrino.
§ xx
The twentieth century
1901 – 2000 · 23 figures
- Image: Wikimedia Commons · CC BY-SA 2.0 · Unknown author Linus Pauling 1901 – 1994 1931: orbital hybridization theory. 1939 book 'The Nature of the Chemical Bond.' Two unshared Nobels (Chemistry 1954, Peace 1962).
- Image: Wikimedia Commons · CC BY-SA 3.0 de · Unknown author Werner Heisenberg 1901 – 1976 1925: matrix mechanics. 1927: the uncertainty principle Δx·Δp ≥ ℏ/2.
- Editorial placeholder · too.foo George Gamow 1904 – 1968 1928: explained alpha decay as quantum tunneling. 1948: Big Bang nucleosynthesis. Popular-science author of the Mr Tompkins books.
- Image: Wikimedia Commons · Attribution · Fot. Comm. A. Petitti, Roma, courtesy of AIP Emilio Segrè Visual Archives, Goudsmit Collection Walter Heitler 1904 – 1981 1927: with London, first quantum calculation of the H₂ molecule. Pioneer of quantum chemistry.
- Image: Wikimedia Commons · No restrictions · Smithsonian Institution Carl Anderson 1905 – 1991 1932: discovered the positron in cosmic ray cloud chamber tracks. 1936 Nobel.
- Image: Wikimedia Commons · Public domain · Unknown author Felix Bloch 1905 – 1983 Introduced the Bloch sphere for spin states. Co-invented NMR with Purcell. 1952 Nobel. appears in the-bloch-sphere
- Image: Wikimedia Commons · Attribution · Los Alamos National Laboratory Hans Bethe 1906 – 2005 1938: derived the proton-proton chain and CNO cycle, explaining how stars actually fuse hydrogen into helium. 1967 Nobel.
- Image: Wikimedia Commons · Public domain · Nobel foundation Sin-Itiro Tomonaga 1906 – 1979 1947: renormalization of QED, independent of Schwinger. 1965 Nobel.
- Image: Wikimedia Commons · Public domain · Nobel Foundation archive Hideki Yukawa 1907 – 1981 1935: predicted the pion as the mediator of the nuclear force. First Japanese Nobel (1949).
- Image: Wikimedia Commons · CC BY-SA 3.0 · Anefo Hendrik Casimir 1909 – 2000 1948: predicted the Casimir effect (force between two uncharged parallel plates due to vacuum mode quantization).
- Image: Wikimedia Commons · Attribution · AIP Emilio Segrè Visual Archives, Gift of Kameshwar Wali Subrahmanyan Chandrasekhar 1910 – 1995 1930: derived the maximum mass of a white dwarf (~1.4 solar masses), a foundational result of stellar structure. 1983 Nobel.
- Image: Wikimedia Commons · Public domain · Nobel foundation Julian Schwinger 1918 – 1994 1948: independent QED renormalization framework. 1965 Nobel with Feynman and Tomonaga.
- Image: Wikimedia Commons · PD-Sweden · The Nobel Foundation Richard Feynman 1918 – 1988 1948: Feynman diagrams. Path integral formulation of QM. 1965 Nobel.
- Image: Wikimedia Commons · CC BY-SA 2.0 · ioerror Freeman Dyson 1923 – 2020 1949: proved Feynman and Schwinger's QED formulations are equivalent. Foundational to all later QFT.
- Image: Wikimedia Commons · CC BY-SA 3.0 · Markus Pössel (User name: Mapos) Roy Glauber 1925 – 2018 1963: rigorous coherent-state theory of light. Foundations of quantum optics. 2005 Nobel.
- Image: Wikimedia Commons · Attribution · Photograph by Mark Godfrey, courtesy of AIP Emilio Segrè Visual Archives, Gift of Vera Rubin Vera Rubin 1928 – 2016 1970s: galactic rotation curves provided the most compelling evidence for dark matter. Foundational to modern cosmology.
- Image: Wikimedia Commons · CC BY-SA 3.0 · Melirius Murray Gell-Mann 1929 – 2019 1964: proposed quarks. Eightfold Way classification of hadrons. 1969 Nobel.
- Image: Wikimedia Commons · CC BY-SA 3.0 · NIMSoffice Heinrich Rohrer 1933 – 2013 Co-invented the scanning tunneling microscope. 1986 Nobel.
- Image: Wikimedia Commons · CC BY-SA 4.0 · Peacearth George Zweig b. 1937 1964: independently proposed quarks (called them 'aces'). Switched to neurobiology.
- Editorial placeholder · too.foo Kip Thorne b. 1940 Co-founded LIGO with Weiss and Drever. Theoretical groundwork for gravitational-wave detection. 2017 Nobel.
- Image: Wikimedia Commons · Public domain · NASA Stephen Hawking 1942 – 2018 1974: showed that black holes emit thermal radiation (Hawking radiation) at temperature ℏc³/(8πGMk_B). Connected gravity, quantum mechanics, and thermodynamics.
- Image: Wikimedia Commons · CC BY-SA 3.0 · Launch_of_IYA_2009,_Paris_-_Grygar,_Bell_Burnell.jpg : Astronomical Institute, Academy of Sciences of the Czech Republic derivative work: Anrie ( talk ) Jocelyn Bell Burnell b. 1943 1967: discovered the first pulsar as a Cambridge grad student. Foundational confirmation of neutron stars.
- Image: Wikimedia Commons · CC BY 2.0 · ibm research zurich Gerd Binnig b. 1947 Co-invented the scanning tunneling microscope at IBM Zürich. 1986 Nobel.