page_title: List of multiple discoveries
section_title: 20th century
hierarchical_section_title: List of multiple discoveries / 20th century
caption_attribution_description: English: Marie Curie
context_page_description: Historians and sociologists have remarked the occurrence, in science, of "multiple independent discovery". Robert K. Merton defined such "multiples" as instances in which similar discoveries are made by scientists working independently of each other. "Sometimes," writes Merton, "the discoveries are simultaneous or almost so; sometimes a scientist will make a new discovery which, unknown to him, somebody else has made years before."
  Commonly cited examples of multiple independent discovery are the 17th-century independent formulation of calculus by Isaac Newton, Gottfried Wilhelm Leibniz and others, described by A. Rupert Hall; the 18th-century discovery of oxygen by Carl Wilhelm Scheele, Joseph Priestley, Antoine Lavoisier and others; and the theory of the evolution of species, independently advanced in the 19th century by Charles Darwin and Alfred Russel Wallace.
  Multiple independent discovery, however, is not limited to such famous historic instances. Merton believed that it is multiple discoveries, rather than unique ones, that represent the common pattern in science.
context_section_description: 1902:  Walter Sutton and Theodor Boveri independently proposed that the hereditary information is carried in the chromosomes.
  1902:  Richard Assmann and Léon Teisserenc de Bort independently discovered the stratosphere.
  E = mc², though only Einstein provided the accepted interpretation – Henri Poincaré, 1900; Olinto De Pretto, 1903; Albert Einstein, 1905; Paul Langevin, 1906.
  Brownian motion was independently explained by Albert Einstein (in one of his 1905 papers) and by Marian Smoluchowski in 1906.
  The Einstein Relation was revealed independently by William Sutherland in 1905, by Albert Einstein in 1905, and by Marian Smoluchowski in 1906.
  1904:  Epinephrine synthesized independently by Friedrich Stolz and by Henry Drysdale Dakin.
  1905:  The chromosomal XY sex-determination system—that males have XY, and females XX, sex chromosomes—was discovered independently by Nettie Stevens, at Bryn Mawr College, and by Edmund Beecher Wilson at Columbia University.
  1907:  Lutetium discovered independently by French scientist Georges Urbain and by Austrian mineralogist Baron Carl Auer von Welsbach.
  Hilbert space representation theorem, also known as Riesz representation theorem, the mathematical justification of the Bra-ket notation in the theory of quantum mechanics – 1907 independently proved by Frigyes Riesz and Maurice René Fréchet.
  The Hardy–Weinberg principle is a principle of population genetics that states that, in the absence of other evolutionary influences, allele and genotype frequencies in a population will remain constant from generation to generation.  This law was formulated in 1908 independently by German obstetrician-gynecologist Wilhelm Weinberg and, a little later and a little less rigorously, by British mathematician G.H. Hardy.
  The Stark–Einstein law (aka photochemical equivalence law, or photoequivalence law) – independently formulated between 1908 and 1913 by Johannes Stark and Albert Einstein. It states that every photon that is absorbed will cause a (primary) chemical or physical reaction.
  Frequency-hopping spread spectrum in radio work was described by Johannes Zenneck (1908), Leonard Danilewicz (1929), Willem Broertjes (1929), and Hedy Lamarr and George Antheil (1942 US patent).
  By 1913, vitamin A was independently discovered by Elmer McCollum and Marguerite Davis at the University of Wisconsin–Madison, and by Lafayette Mendel and Thomas Burr Osborne at Yale University, who studied the role of fats in the diet.
  Bacteriophages (viruses that infect bacteria) – Frederick Twort (1915), Félix d'Hérelle (1917).
  Rotor cipher machines – Theo A. van Hengel and R.P.C. Spengler (1915); Edward Hebern (1917); Arthur Scherbius (Enigma machine, 1918); Hugo Koch (1919); Arvid Damm (1919).
  Sound film – Joseph Tykociński-Tykociner (1922), Lee De Forest (1923).
  The Big Bang theory of the universe—that the universe is expanding from a single original point—was developed from the independent derivation of the Friedmann equations from Albert Einstein's equations of general relativity by the Russian, Alexander Friedmann, in 1922, and by the Belgian, Georges Lemaître, in 1927.  The Big Bang theory was confirmed in 1929 by the American astronomer Edwin Hubble's analysis of galactic redshifts.  But the Big Bang theory had been presaged three-quarters of a century earlier in the American poet and short-story writer Edgar Allan Poe's then much-derided essay, Eureka: A Prose Poem (1848),
  Georgios Papanikolaou is credited with discovering as early as 1923 that cervical cancer cells can be detected microscopically, though his invention of the Pap test went largely ignored by physicians until 1943. Aurel Babeş of Romania independently made similar discoveries in 1927.
  "Primordial soup" theory of the evolution of life from carbon-based molecules – Alexander Oparin (1924), J.B.S. Haldane.
  Jet stream was detected in the 1920s by Japanese meteorologist Wasaburo Oishi, whose work largely went unnoticed outside Japan because he published his findings in Esperanto. Often given some credit for discovery of jet streams is American pilot Wiley Po
caption: Marie Curie
exif: {}