1925 in science

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The year 1925 in science and technology involved some significant events, listed below.

Astronomy and space science

  • January 1 – Cecilia Payne completes her PhD thesis Stellar Atmospheres: a Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars{{cite thesis|last=Payne|first=Cecilia H.|title=Stellar Atmospheres: a Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars|publisher=Radcliffe College|year=1925|type=PhD|bibcode=1925PhDT.........1P|oclc=1443459|id={{ProQuest|301786588}}}} at Radcliffe College of Harvard University, providing spectral evidence that stars are composed almost entirely of hydrogen with helium, contrary to scientific consensus at the time; however, her findings will be vindicated by 1929 and astronomer Otto Struve will describe her work as "the most brilliant PhD thesis ever written in astronomy".{{cite web|url=https://www.aps.org/publications/apsnews/201501/physicshistory.cfm|title=January 1, 1925: Cecilia Payne-Gaposchkin and the Day the Universe Changed|website=American Physical Society|date=January 2015|accessdate=2021-04-01}}

Biology

Cartography

  • Adams hemisphere-in-a-square projection published by American cartographer Oscar S. Adams.{{citation|title=Cartographic Science: A Compendium of Map Projections, with Derivations|first=Donald|last=Fenna|publisher=CRC Press|location=Boca Raton|year=2006|isbn=9780849381690|url=https://books.google.com/books?id=8LZeu8RxOIsC&pg=PA357|page=357}}.

Chemistry

  • May – Rhenium is discovered by Walter Noddack and Ida Tacke in Berlin, the last stable, non-radioactive naturally occurring element to be found.{{cite book|title=Nature's Building Blocks: An A-Z Guide to the Elements|last=Emsley|first=John|publisher=Oxford University Press|year=2001|isbn=0-19-850340-7|chapter=Rhenium|pages=[https://archive.org/details/naturesbuildingb0000emsl/page/358 358–360]|url=https://archive.org/details/naturesbuildingb0000emsl/page/358}}
  • The Fischer–Tropsch process for production of hydrocarbons is first developed by Franz Fischer and Hans Tropsch at the Kaiser-Wilhelm-Institut für Kohlenforschung in Mülheim an der Ruhr, Germany.

History of science

Physics

Technology

  • June 13 – Charles Francis Jenkins achieves the first synchronized transmission of pictures and sound, using 48 lines, and a mechanical system. A 10-minute film of a miniature windmill in motion is sent across 5 miles from Anacostia to Washington, DC. The images are viewed by representatives of the Bureau of Standards, the U.S. Navy, the Department of Commerce and others. Jenkins calls this "the first public demonstration of radiovision".
  • October 2 – John Logie Baird successfully transmits the first television pictures with a greyscale image, in London.{{cite book|first=R. W.|last=Burns|title=Television: An International History of the Formative Years|location=London|publisher=Institution of Electrical Engineers|isbn=9780852969144|page=264}}
  • October 22 – Julius Edgar Lilienfeld files the first patent for a form of field-effect transistor.{{US patent|1745175}} Method and apparatus for controlling electric currents, first filed in Canada, describing a device similar to a MESFET. Granted 28 January 1930. {{cite book|first=Thomas H.|last=Lee|title=The Design of CMOS Radio-Frequency Integrated Circuits|edition=New|publisher=Cambridge University Press|year=2004|isbn=9780521835398|pages=167ff}}
  • November 4 – Charles F. Brannock files a patent for the Brannock Device for measuring shoe sizes."Foot-Measuring Instrument." [https://patents.google.com/patent/US1682366 U.S. Patent 1,682,366.]
  • late 1925 or early 1926Vladimir K. Zworykin demonstrates a cathode-ray tube television system using Braun tubes at the Westinghouse Electric laboratories in Pittsburgh, Pennsylvania.
  • Jonas Hesselman introduces the Hesselman engine.

Other events

  • Sinclair Lewis's novel Arrowsmith is published in the United States, notable in having the culture of medical science as a principal theme.{{cite journal|url=http://mh.bmj.com/cgi/content/full/32/2/82|title=The novel Arrowsmith, Paul de Kruif (1890-1971) and Jacques Loeb (1859–1924): a literary portrait of "medical science"|first=H. M.|last=Fangerau|journal=Medical Humanities|volume=32|year=2006|pages=82–87|issue=2|doi=10.1136/jmh.2006.000230|pmid=23673799}}

Awards

Births

Deaths

References

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Category:20th century in science

Category:1920s in science