Franz Eugen Simon

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Franz Eugen ("Francis") Simon
Franz Eugen Simon at the meeting of the Bunsen Society in 1928

Francis Simon (later in the United Kingdom: Sir Francis Simon CBE , * 2. July 1893 in Berlin , † 31 October 1956 in Oxford ) was a German - British physical chemist and physicist , which the gaseous diffusion method of isotope separation of 235 uranium developed and thus made a significant contribution to the development of the first atomic bomb .

Origin and career

Franz Eugen Simon came from an upper-class German-Jewish family in Berlin; the physicist Kurt Mendelssohn was his cousin. In Berlin he attended the old-language Kaiser-Friedrich-Reformgymnasium in Charlottenburg, whereby his inclinations towards the natural sciences were already evident during his school days. Among other things, at the suggestion of Leonor Michaelis , a friend of the family, he made the decision to study natural sciences. After graduating from high school in 1912, Simon began studying first in Göttingen and then in Munich , which he had to interrupt in autumn 1913 because he was called up for military service as a one-year volunteer . Shortly before the end of his year of service, the First World War broke out and Simon continued to serve on the Western Front from 1914 to 1918. He was injured in a gas attack and wounded twice, most recently seriously on November 9, 1918, just two days before the armistice came into force , received the Iron Cross 1st Class as an award and was promoted to officer. In the summer of 1919, after his war injuries had healed, he was able to leave the military hospital.

Simon belonged to a generation who had lost many years of academic training through their participation in the war. He began his studies again, now in Berlin at the Friedrich-Wilhelms University (now Humboldt University of Berlin ), where he in 1921 at Walther Nernst on a theme from the area Low Temperature Physics to Dr. phil. PhD in physics . His academic teachers in Berlin also included Max Planck , Max von Laue and Fritz Haber . In 1922 Simon became a scientific assistant in Nernst's laboratory at the Kaiser Wilhelm Institute for Physics in Dahlem . In the same year he married Charlotte Münchhausen. In 1924 he became a private lecturer and in 1927 an associate professor (Extraordinarus) in Berlin. In his Berlin years he developed an extraordinary scientific productivity and published a total of 50 scientific papers from 1922 to 1931. Most of them dealt with problems of thermodynamics and low temperature physics.

In 1931 Simon followed a call to the Technical University of Wroclaw , where he took over the position of director of the local institute for physical chemistry. In 1932, when the political prospects in Germany darkened with the swelling of the National Socialist movement, Simon was briefly visiting professor at the University of California at Berkeley. There he developed, among other things, a method for liquefying helium . After the so-called " seizure of power " by the National Socialists in January 1933, Simon was initially spared from anti-Semitic measures of the new regime (on April 7, 1933, " Law for the Restoration of the Professional Civil Service "), unlike other colleagues who were considered Jews Wish Hindenburg's active World War II participants were excluded. But Simon was realist enough to realize that he would no longer have a longer-term academic future in Germany. He resigned from his post as director of the institute and in September 1933 took a research position in the laboratory of Frederick Lindemann in the Clarendon Laboratory of the University of Oxford in Great Britain. In England he called himself "Francis". His job opportunities there were initially very limited and he did not have anywhere near the resources that he had in Breslau or Berlin. In 1938 he and Bernard Vincent Rollin discovered the Rollin effect of thin films of liquid helium. Gradually, the job opportunities improved and in 1939 Simon finally acquired British citizenship. After the outbreak of war in 1939, Simon offered to help the British government. However, she was suspicious of German emigrants and initially turned down the offer. Faced with a feared invasion of the British Isles after the fall of France in 1940 , Simon had his family evacuated to Canada. However, he himself remained in Cambridge. There he became increasingly interested in the problem of constructing an atomic bomb, as he and others feared that Nazi Germany could develop such weapons. In 1940 he was considered one of the world's top experts in the field of gas diffusion was, by the MAUD Committee commissioned the feasibility of enrichment of uranium - isotope 235 to investigate U by gaseous diffusion. He worked out the technical basis for this together with his colleague Nicholas Kurti . The experience gained later flowed into the Manhattan project .

Immediately after the end of the war in 1945, he became a professor of thermodynamics at Christ Church College in Oxford and developed the laboratory into one of the world's leading laboratories for low-temperature physics.

Simon fell ill and died less than a month after he was appointed to succeed Frederick Lindemann as director of the Clarendon Laboratory, at the age of 63 in Oxford.

Honors

In 1941 Simon was elected as a member (" Fellow ") in the Royal Society , which in 1948 awarded him the Rumford Medal . In 1946 he was appointed Commander of the Order of the British Empire (CBE). In 1952 he was elected to the American Academy of Arts and Sciences . In 1955 he was beaten to the Knight Bachelor . Simon joked that he was definitely the only person who had received both the Iron Cross and the CBE.

literature

swell

Unless expressly stated otherwise, the biographical information is taken from the following obituaries.

Individual evidence

  1. ^ Nicholas Kurti: Kurt Mendelssohn . In: Physics Today , Vol. 34, No. 4 (April 1981), pp. 87-89 (obituary).
  2. ↑ a b c d e f g P. W. Bridgman : Sir Francis Simon. Science. 1960; 131 (3414): 1647-1654. doi: 10.1126 / science.131.3414.1647
personal data
SURNAME Simon, Franz Eugen
ALTERNATIVE NAMES Simon, Sir Francis
BRIEF DESCRIPTION German-British physical chemist
DATE OF BIRTH July 2, 1893
PLACE OF BIRTH Berlin
DATE OF DEATH October 31, 1956
Place of death Oxford