History of Physics and Astronomy

1900 AD to 1924 AD

This section shows the important events in Physics and Astronomy from 1900 AD until 1924 AD. The names of people are highlighted in blue, important people are in bold blue.

1900 Black body radiation – Rayleigh- Jeans law
1900 Conduction in metals due to electron motion demonstrated - Drude
1900 Conductivity of gases – Geitel and Wilson
1900 Cosmic rays predicted – Wilson
1900 Gamma rays identified – Villard
1900 Quantum theory - Planck
1900 Searle's apparatus for elasticity
1900-1958 Pauli
1901 Black body radiation curve – Planck
1901 MKS units Giorgi
1901 Nobel prizes instituted
1901 Radio signal – first transatlantic
1901 Rφntgen – Nobel prize for Physics
1901-1954 Fermi
1901-1958 Lawrence
1902 Constant flow method for J – Callendar and Barnes
1902 Liquefaction of air – Claude
1902 Lorentz and Zeeman - Nobel prize for Physics
1902 Spontaneous disintegration - Soddy
1903 Aeroplane – first flight – Wright brothers
1903 Curies and Becquerel – Nobel prize for Physics
1903 Thermionic emission theory - Richardson
1903 Ultra microscope
1904 Alpha particle experiments - Rutherford
1904 Planetary model of the atom proposed - Hantaro Nagaoka
1904 Thermionic diode – Fleming (first vacuum tube patented)
1904 Wireless pulses – depth finding
1904-1967 Oppenheimer

1905 Lennard – Nobel prize for Physics
1905 Lowell – search for a planet beyond Neptune
1905 Photoelectric cell
1905 Photon theory for photoelectric effect - Albert Einstein
1905 Relativity (special) – Einstein
1905-1950 Jansky
1906 Alpha particle – e/m measurement – Rutherford
1906 Earthquake waves used by Oldham to prove that the Earth has a core
1906 Lyman series in hydrogen
1906 Thermodynamics– third law – Nernst
1906 Thomson, J.J – Nobel prize for Physics
1906 Triode – Forrest
1907 Domain theory of ferromagnetism – Weiss
1907 Expansion – Henning's method
1907 Michelson – Nobel prize for Physics
1907 Zeeman – Nobel prize for Physics
1908 Coal mines – eight hour day
1908 Helium liquefied – Kammerlingh Onnes – 0.7K
1908 Mount Wilson 100" opened
1908 Sunspots – large magnetic field discovered - Hale
1908 Superfluidity - Kammerlingh Onnes
1909 Alpha particle - identification of the alpha particle – Rutherford and Royds
1909 Alpha particle scattering

1910 Halley's comet returns
1910 Knudsen gauge
1911 Cosmic ray detection in balloons – Victor Hess
1911 Millikan's method for the electron charge
1911 Nuclear atom theory – Rutherford
1911 Superconductivity – Onnes
1912 Cepheid – period-luminosity relation
1912 Cloud chamber – Wilson
1912 Continental drift theory proposed – Wegener
1912 Curvature of space- time - Einstein
1912 Mass spectrograph – Thomson
1912 Planck's constant - measurement by Millikan
1912 Red shift of galaxies observed – Vesto Slipher
1912 Titanic sunk
1912 X ray diffraction – Laue
1912 X ray wavelength measured using crystal diffraction - Braggs
1913 Atomic theory – Bohr orbits
1913 Hertzsprung- Russel diagram finalised
1913 Isotopes – Soddy
1913 Positive ray analysis – neon isotopes
1913 Stark effect
1913 X ray diffraction – Friedrich and Knipping
1913 X ray tube – Coolidge
1913 X rays – Moseley
1914 Beta particle spectra - Chadwick
1914 Frank and Hertz – stationary states in the atom – energy levels
1914 Laue – Nobel Prize for Physics
1914 The World Set Free – H.G.Wells
1914-1918 War - First World War

1915 Bragg – Nobel prize for Physics
1915 Diffusion pump - Gaede
1915 Relativity (General Theory)
1915 White dwarfs – first discovered
1916 Elliptical orbits– Sommerfield
1916 Photoelectric equation – Millikan
1917 Mount Wilson 100" opened (date clash?)
1918 Barton's pendulums
1918 Planck – Nobel prize for Physics
1919 Aston mass spectrograph
1919 Deflection of light in a gravitational field – total solar eclipse
1919 Gravitational lensing predicted – Oliver Lodge
1919 Milky Way layout described – Shapley
1919 Rutherford – director of Cavendish Laboratory
1919 Rutherford – transmutation of atom
1919 Stark – Nobel prize for Physics

1920 Proton – name suggested by Rutherford
1920 Radio broadcasting is regular in USA
1921 Einstein – Nobel prize for Physics
1921 Light – speed of light in water - Michelson
1922 Aston and Bohr – Nobel prize for Physics
1922 BBC founded
1922 Cosmic rays – electroscopes in balloons
1923 Andromeda galaxy –distance – Hubble – Cepheids and 100" reflector
1923 Compton effect
1924 De Broglie – wave equation for a particle (l=h/p)
1924 Galaxies shown to exist outside the Milky Way - Hubble
1924 Stellar spectral classification – Henry Draper catalogue published