Hedwig Kohn

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Hedwig Kohn
Breslau University
University of North Carolina
Wellesley College
Duke University
Thesis (1913)
Doctoral advisorsOtto Lummer, Rudolf Ladenburg

Hedwig Kohn (5 April 1887 – 26 November 1964) was a physicist who was one of only three women (along Lise Meitner and Hertha Sponer) to obtain habilitation (the qualification for university teaching) in physics in Germany before World War II. Born in Breslau in the German Empire (now Wrocław, Poland), she was forced to leave Germany during the Nazi regime because she was Jewish. She continued her academic career in the United States, where she settled for the rest of her life.

Biography

Early life

Born in Breslau (now Wrocław, Poland), Kohn was the daughter of Georg Kohn, a wholesale merchant of fine cloth, and Helene Hancke, a member of a well-to-do family.

German Jews
.

In 1907, Kohn enrolled in Breslau University (Universität Breslau, now University of Wrocław), a year before women were officially allowed to matriculate. She became the second woman to enter the physics department.[2] She obtained her doctorate in physics under Otto Lummer in 1913 and was soon appointed as Lummer's assistant.[1] She stayed at the university's Physics Institute during World War I, teaching and advising doctoral students in spite of her youth, even receiving a medal for this service after the war. She obtained her habilitation in 1930.[1]

Kohn was trained by Lummer in the quantitative determination of the

emission lines of atoms and molecules
.

Escape from Germany

Kohn was dismissed from her position in 1933 due to Nazi regulations which barred

Kovno
and murdered.

Although a good and respected physicist, she was not internationally famous. The hurdles to her obtaining a job offer out of Germany were enhanced by the lack of university positions in western countries during the Great Depression, her German nationality, her age and being a woman. In some cases, antisemitism may have been a usually unspoken factor.

Offered temporary positions at three women's colleges in the United States through the aid of Rudolf Ladenburg, Lise Meitner, Hertha Sponer, the American Association of University Women, and many others,[1] Kohn left Germany. She had been given a visa to the United Kingdom in 1939, but it was cancelled because of World War II; she eventually secured a visa to travel to Sweden and immediately went there in July 1940.

On receiving a visa from the United States, she then moved there.

Leningrad, Moscow, Vladivostok, Yokohama, San Francisco, and Chicago
.

Life in United States

When Kohn arrived in the United States in January 1941, she was seriously ill.[1] After recovering, Kohn taught at the Women's College of the University of North Carolina at Greensboro for a year and a half.[1]

In 1942, she began teaching at

flame spectroscopy while at the college.[1]

She was a member of a number of professional associations in the United States, including the American Physical Society, the American Association of Physics Teachers, and Sigma Xi: The Scientific Research Honor Society.[3]

Upon Kohn's retirement as

post-doctoral fellows to assist in her study of flame spectroscopy.[1] She worked there until very shortly before her death in 1964.[1]

Legacy

Kohn was trained by Otto Lummer in the quantitative determination of the

emission lines of atoms and molecules. She further developed such methods and devised ways of extracting information from intensity measurements and from emission line shapes. She wrote 270 pages in the leading physics text of the 1930s and 1940s in Germany, received one patent, and wrote numerous articles in scientific journals, some of which were still being cited into the 2000s.[4]
Kohn also published a textbook that was used to introduce students to radiometry well into the 1960s. Two of her students became professors in Germany.

A Google Doodle on 5 April 2019 commemorated Kohn's 132nd birth anniversary.[5][6][7]

Published works

  • Müller-Pouillets Lehrbuch der Physik. (II. Auflage), unter Mitwirkung zahlreicher Gelehrter herausgegeben von
    Karl W. Meissner
    : 1929.
  • Kohn, Hedwig (1929). "Photometrie". Band II (in German) (22): 1104–1320.
  • Kohn, Hedwig (1929). "Temperaturbestimmung auf Grund von Strahlungsmessungen". Band II (in German) (25): 1428–1469.
  • Kohn, Hedwig (1929). "Ziele und Grenzen der Lichttechnik". Band II (in German) (26): 1470–1482.
  • Kohn, Hedwig (1932). Umkehrmessungen an Spektrallinien zur Bestimmung der Gesamtabsorption und der Besetzungszahlen angeregter Atomzustände (in German). Vol. 33. Phys. Zeitschrift. pp. 957–963.

Further reading

  • Winnewisser, Brenda P (November 2003). "Hedwig Kohn – eine Physikerin des zwanzigsten Jahrhunderts" [Hedwig Kohn – a physicist of the twentieth century]. Physik Journal (in German): 51–57.
  • Winnewisser, Brenda P. (1998). "The Emigration of Hedwig Kohn, Physicist, 1940". Mitteilungen der Österreichischen Gesellschaft für Wissenschaftsgeschichte. (in German): 41–58. Communications of the Austrian Society for the History of Science
  • Winnewisser, Brenda P (2007). "Hedwig Kohn". In Hyman, Paula E.; Ofer, Dalia (eds.). Jewish Women. A Comprehensive Historical Encyclopedia (CD). Jerusalem: Shalvi Publishing.
    ISBN 978-0827608672
    .

References

  1. ^ a b c d e f g h i j k l Winnewisser, Brenda P. "Hedwig Kohn". Jewish Women's Archive. Retrieved 5 April 2019.
  2. ^ Kuhn, Thomas S. (7 June 1962). "Oral History Interviews: Hedwig Kohn". American Institute of Physics. Retrieved 5 April 2019.
  3. ^
    ISSN 0031-9228
    .
  4. doi:10.1016/0022-4073(64)90060-3
    . Retrieved 5 April 2019.
  5. ^ "Hedwig Kohn's 132nd Birthday". 5 April 2019. Retrieved 5 April 2019.
  6. ^ Ryan, Jackson. "Google Doodle celebrates pioneering physicist Hedwig Kohn". CNET. Retrieved 5 April 2019.
  7. ^ "Google celebrates Hedwig Kohn's 132nd Birthday with colorful doodle". Retrieved 5 April 2019.

External links

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