1927 in science
Astronomy and astrophysics
- Edward Emerson Barnard's A Photographic Atlas of Selected Regions of the Milky Way is published posthumously.
- The Cholodny-Went model of tropism in emerging monocotyledon shoots is first proposed by Nikolai Cholodny of the University of Kiev.
- Fritz London and Walter Heitler apply quantum mechanics to explain covalent bonding in the hydrogen molecule, which marks the birth of quantum chemistry.
- American biologist Raymond Pearl publishes an influential attack on the basic assumptions of eugenics.
- Publication of the 2nd edition of Principia Mathematica by Alfred North Whitehead and Bertrand Russell, one of the most important and seminal works in mathematical logic and philosophy.
- February 23 – German theoretical physicist Werner Heisenberg writes a letter to fellow physicist Wolfgang Pauli in which he describes his uncertainty principle for the first time.
- April – Abbé Georges Lemaître publishes in the Annales de la Société Scientifique de Bruxelles "Un Univers homogène de masse constante et de rayon croissant rendant compte de la vitesse radiale des nébuleuses extra-galactiques" proposing the theory of the expansion of the Universe, deriving what will become known as Hubble's law, making the first estimation of what will become called the Hubble constant, and proposing what becomes known as the Big Bang theory of the origin of the Universe, which he calls his 'hypothesis of the primeval atom'.
- October – The fifth Solvay Conference meets in Brussels to discuss the newly formulated quantum mechanics. Albert Einstein attacks the theories of Niels Bohr and Werner Heisenberg.
- August 2 – American electrical engineer Harold Stephen Black invents the negative-feedback amplifier.
- September 7 – Philo Farnsworth's electronic image dissector television camera tube transmits its first image at his laboratory at 202 Green Street in San Francisco.
- November 5 – Completion of a bridge by Westinghouse Electric and Manufacturing in Turtle Creek, Pennsylvania, the world's first railroad bridge of wholly welded construction.
- Date unknown - Emil Lerp invented the transportalble gasoline chainsaw.
- Nobel Prizes
- Copley Medal: Charles Sherrington
- Wollaston Medal for Geology: William Whitehead Watts
- January 29 – Lewis Urry (died 2004), Canadian inventor of the long-lasting alkaline battery.
- March 9 – Julian Tudor Hart, British physician.
- March 16 – Vladimir Komarov (died 1967), Russian cosmonaut on Soyuz 1.
- April 10 – Marshall Warren Nirenberg (died 2010), American biochemist and geneticist; recipient of Nobel Prize in Physiology or Medicine.
- April 18 – Nicole Grasset (died 2009), Swiss-French medical virologist and microbiologist-epidemiologist.
- April 26 – Anne McLaren (died 2007), English developmental biologist.
- April 29 – Walter Thirring (died 2014), Austrian mathematical physicist.
- June 10 – Eugene Parker, American solar astrophysicist.
- June 21 – Ye Shuhua, Chinese astronomer.
- July 2 – R. J. G. Savage (died 1998), Northern Ireland-born palaeontologist.
- July 29 – Gerald Westbury (died 2014), English cancer surgeon.
- August 2 – Gabriel Horn (died 2012), English biologist.
- August 9 – Marvin Minsky (died 2016), American computer scientist, pioneer of artificial intelligence.
- September 4 – John McCarthy (died 2011), American computer scientist and cognitive scientist.
- October 27 – Mikhail Postnikov (died 2004), Soviet mathematician, known for his work in algebraic and differential topology.
- November 12 – Yutaka Taniyama (suicide 1958), Japanese mathematician.
- November 13 – Billy Klüver (died 2004), Swedish-American engineer, co-founded Experiments in Art and Technology
- November 20 – Kikuo Takano (died 2006), Japanese poet and mathematician.
- December 23 – Edith Irby Jones, born Edith Mae Irby, African American physician.
- December 27 – George Streisinger (died 1984), Hungarian-born molecular biologist; first person to clone a vertebrate.
- January 19 – Carl Gräbe (born 1841), German chemist.
- February 9 – Charles Walcott (born 1850), American paleontologist.
- March 27 – William Healey Dall (born 1845), American malacologist and explorer.
- May 2 – Ernest Starling (born 1866), English physiologist.
- August 3 – Edward B. Titchener (born 1867), American structuralist psychologist.
- August 13 – James Oliver Curwood (born 1887), American novelist and conservationist.
- September 14 – Julian Sochocki (born 1842), Polish-born mathematician.
- October 2 – Svante Arrhenius (born 1859), Swedish winner of the Nobel Prize in Chemistry.
- November 11 – Wilhelm Johannsen (born 1857), Danish plant physiologist and geneticist.
- December 2 – Paul Heinrich von Groth (born 1843), German mineralogist.
- December 24 – Vladimir Bekhterev (born 1857), Russian psychologist.
- Heitler, Walter; London, Fritz (1927). "Wechselwirkung neutraler Atome und homöopolare Bindung nach der Quantenmechanik". Zeitschrift für Physik. 44: 455–472. Bibcode:1927ZPhy...44..455H. doi:10.1007/BF01397394.
- Grattan-Guinness, Ivor (2003). Companion Encyclopedia of the History and Philosophy of the Mathematical Sciences. Johns Hopkins University Press. p. 1266.
- Mehra, Jagdish; Rechenberg, Helmut (2001). The Historical Development of Quantum Theory. Springer. p. 540.
- "A brief history of climate change". BBC. Retrieved 2015-06-17.
- Pearl, Raymond (1927). "The biology of superiority". American Mercury. 12: 257–266.
- Allen, Garland E. (1987). "The role of experts in scientific controversy". In Engelhardt, Hugo Tristram; Caplan, Arthur Leonard. Scientific controversies: case studies in the resolution and closure of disputes in science and technology. Cambridge University Press. pp. 169‒202. ISBN 9780521275606.
- "World of Scientific Discovery on Antonio Egas Moniz". BookRags. Retrieved 2011-12-27.
- Lemaître, G. (April 1927). "Un Univers homogène de masse constante et de rayon croissant rendant compte de la vitesse radiale des nébuleuses extra-galactiques" (PDF). Annales de la Société Scientifique de Bruxelles (in French). 47: 49–59. Bibcode:1927ASSB...47...49L. ("A Homogeneous Universe of Constant Mass and Growing Radius Accounting for the Radial Velocity of Extra-galactic Nebulæ".)
- van den Bergh, Sidney (2011-06-06). "The Curious Case of Lemaitre's Equation No. 24". arXiv: [physics.hist-ph].
- Block, David L. (2011-06-20). "A Hubble Eclipse: Lemaitre and Censorship". Astrophysics and Space Science Library: 89–96. arXiv: [physics.hist-ph]. doi:10.1007/978-3-642-32254-9_8.
- Reich, Eugenie Samuel (2011-06-27). "Edwin Hubble in translation trouble". Nature. doi:10.1038/news.2011.385. Retrieved 2011-12-27.
- Livio, Mario (2011-11-10). "Lost in translation: Mystery of the missing text solved". Nature. 479 (7372): 171–3. Bibcode:2011Natur.479..171L. doi:10.1038/479171a. PMID 22071745. Retrieved 2011-12-27.
- "Big bang theory is introduced, 1927". People and Discoveries. PBS. 1998. Retrieved 2011-12-27.
- "1927: Lemaître – Big Bang". Chemsoc Timeline. Royal Society of Chemistry. 2004. Retrieved 2011-12-27.
- Pescatore, Jean-Pierre; Borgeot, Jean-Henri (2010). "Chapter 10: Welding Steel Structures". In Blondeau, Regis. Metallurgy and mechanics of welding: processes and industrial application. John Wiley & Sons. p. 359. ISBN 9780470393895.