- Hedwig Kohn
Hedwig Kohn (
April 5 ,1887 – 1964), was a pioneer inphysics and one of only three women who obtained Habilitation (the qualification foruniversity teaching inGermany ) in physics beforeWorld War II . She and the other two physicists,Lise Meitner andHertha Sponer , were forced to leave Germany during the Nazi regime.Early life
Born in
Breslau ,Province of Silesia , Kohn was the daughter of Georg Kohn (1850–1932), a wholesale merchant of finecloth , and Helene Hancke (1859–1926), a member of a well-to-do Breslau family. Hedwig entered the university in Breslau in 1907. She obtained herdoctorate in physics underOtto Lummer in 1913, and was soon appointed as Lummer's assistant. She stayed at the university's Physics Institute duringWorld War I , and obtained her Habilitation in 1930.Escape from Germany
Kohn was dismissed from her position in 1933, due to Nazi regulations which barred
Jew s fromgovernment service. She survived by fulfillingcontract s forapplied research in theillumination industry until 1938, when she found herself without work or financial resources and came very close to being a victim of theHolocaust . Finally, she was offeredtemporary positions at three women's colleges in theUnited States through the aid ofRudolf Ladenburg , Lise Meitner, Hertha Sponer, theAmerican Association of University Women (AAUW ), and many others. She obtained a visa and left Germany in July 1940.Life in America
The journey to her first position, at the Women's College of the University of North Carolina in Greensboro, took Kohn through
Berlin ,Stockholm ,Leningrad ,Moscow ,Vladivostok ,Yokohama ,San Francisco , andChicago . She taught at the Women's College of the University of North Carolina for a year and a half. In 1942, she began teaching atWellesley College inMassachusetts . She retired in 1952 as aprofessor . Upon her retirement, Hertha Sponer, then professor of physics atDuke University inDurham, North Carolina , offered her a position as a research associate. Kohn set up a laboratory at Duke and resumed research, guiding twograduate student s to their doctorates and recruiting twopost-doctoral fellow s. She worked there until very shortly before her death, in 1964.Contributions to science
Kohn was trained by Lummer in the quantitative determination of the intensity of light, both from broad-band sources, such as a "black body", and from the discrete
emission line s ofatom s andmolecule s. 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 onepatent , and wrote numerous articles in scientific journals, some of which were still being cited into the 1980s. Two of her students became professors in Germany.elected bibliography
* "Mueller-Pouillets Lehrbuch der Physik". (II. Auflage), unter Mitwirkung zahlreicher Gelehrter herausgegeben von
A. Eucken , O.Lummer (+),E. Waetzmann . In fuenf Baenden: I. "Mechanik und Akustik"; II. "Lehre von der strahlenden Energie (Optik)"; III. "Waermelehre"; IV. "Elektizitaet und Magnetismus"; V. "Physik der Erde und des Kosmos (einschl. Relativitaetstheorie)".Braunschweig : 1925-1929. Band II, Zweite H{a}lfte, Erster Teil (Volume II, 2. half, 1. part), volume editorKarl W. Meissner : 1929.
* Kohn, Hedwig. In Band II, Chapter 22, "Photometrie." 1104ñ1320; Chapter 25, "Temperaturbestimmung auf Grund von Strahlungsmessungen." 1428ñ1469; Chapter 26, "Ziele und Grenzen der Lichttechnik." 1470ñ1482.
* Kohn, Hedwig, Umkehrmessungen an Spektrallinien zur Bestimmung der Gesamtabsorption und der Besetzungszahlen angeregte Atomzust"ande, "Phys. Zeitschrift" 1932: 33, 957-963.Further reading
* Winnewisser, Brenda P. Hedwig Kohn ó eine Physikerin des zwanzigsten Jahrhunderts. "Physik Journal". (2003): November, 51-57.
* Winnewisser, Brenda P. The Emigration of Hedwig Kohn, Physicist, 1940. "Mitteilungen der ÷sterreichischen Gesellschaft f¸r Wissenschaftgeschichte." (1998): 41ñ58.
* Winnewisser, Brenda P. Hedwig Kohn, in "Jewish Women. A Comprehensive Historical Encyclopedia." Shalvi Publishing Ltd. Jerusalem 2007.
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