Sir Francis Simon (2 July 1893 – 31 October 1956), was a German and later British physical chemist and physicist who devised the

gaseous diffusion Gaseous diffusion is a technology that was used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF6) through microporous membranes. This produces a slight separation (enrichment factor 1.0043) between the molecules containi ...

method, and confirmed its feasibility, of separating the isotope

Uranium-235 Uranium-235 ( or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nat ...

and thus made a major contribution to the creation of the

atomic bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

Early life

Born Franz Eugen Simon to a Jewish family in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

, Franz was the son of Ernst Simon and Anna Mendelssohn, daughter of the mathematician Philibert Mendelssohn. Two of his cousins,

Kurt Mendelssohn Kurt Alfred Georg Mendelssohn FRS (7 January 1906, Berlin-Schoeneberg – 18 September 1980) was a German-born British medical physicist, elected a Fellow of the Royal Society in 1951. Family life He was the only child of Ernst Moritz Mendel ...

and Heinrich Mendelssohn, were also scientists. He won the

Iron Cross The Iron Cross (, , abbreviated EK) was a military decoration in the Kingdom of Prussia, the German Empire (1871–1918), and Nazi Germany (1933–1945). The design, a black cross pattée with a white or silver outline, was derived from the in ...

First Class during

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. He received his doctoral degree from the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

, working in the research group of

Walther Nernst Walther Hermann Nernst (; 25 June 1864 – 18 November 1941) was a German physical chemist known for his work in thermodynamics, physical chemistry, electrochemistry, and solid-state physics. His formulation of the Nernst heat theorem helped ...

on low-temperature physics related to the Nernst Heat Theorem, which is one statement of the

Third law of thermodynamics The third law of thermodynamics states that the entropy of a closed system at thermodynamic equilibrium approaches a constant value when its temperature approaches absolute zero. This constant value cannot depend on any other parameters characte ...

, and is sometimes referred to as the Nernst-Simon Heat Theorem. In 1931 he was appointed Professor of Physical Chemistry at the Technische Hochschule of Breslau.

Emigration

The rise of anti-Semitic fascism in Germany in the 1930s caused him and his wife to consider emigrating. Aware of his concerns

Frederick Lindemann, 1st Viscount Cherwell Frederick Alexander Lindemann, 1st Viscount Cherwell, ( ; 5 April 18863 July 1957) was a British physicist who was prime scientific adviser to Winston Churchill in World War II. He was involved in the development of radar and infra-red guida ...

met him in

's laboratory during Easter 1933, and invited him to join the

Clarendon Laboratory The Clarendon Laboratory, located on Parks Road within the Science Area in Oxford, England (not to be confused with the Clarendon Building, also in Oxford), is part of the Department of Physics at Oxford University. It houses the atomic and la ...

at the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

. He was also able to offer him a two-year grant research from

Imperial Chemical Industries Imperial Chemical Industries (ICI) was a British Chemical industry, chemical company. It was, for much of its history, the largest manufacturer in Britain. Its headquarters were at Millbank in London. ICI was listed on the London Stock Exchange ...

(ICI) of £800. Simon resigned on 1 July 1933, but before he could leave an official demanded that he and his wife surrender their passports. Simon then flung his Iron Cross and other medals onto the table. Their passports were later returned, for reasons unknown. Using the services of a corrupt customs official Simon was able to take his research equipment with him. His wife and children followed him two months later. Upon arrival in the UK, he started using the

Anglicised Anglicisation or anglicization is a form of cultural assimilation whereby something non-English becomes assimilated into or influenced by the culture of England. It can be sociocultural, in which a non-English place adopts the English language ...

name "Francis".

Work in England

Using the equipment he had brought with him from Germany he performed pioneering work in low temperature physics. In 1936 he was able to produce the first liquid

helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...

by using magnetic cooling at a laboratory at

Bellevue Bellevue means "beautiful view" in French. Bellevue or Belle Vue may refer to: Places Australia * Bellevue, Queensland * Bellevue, Western Australia * Bellevue Hill, New South Wales Canada * Bellevue, Alberta * Bellevue, Newfoundlan ...

near Paris. His ICI grant was extended to 1938 which allowed him to turn down an offer of a 10-year contract as Professor of Physical Chemistry at Istanbul. In 1936 despite being supported by

Einstein Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...

, Nernst,

Planck Max Karl Ernst Ludwig Planck (; ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918. Planck made many substantial contributions to theoretical p ...

and Rutherford he was unsuccessful in beating

Mark Oliphant Sir Marcus Laurence Elwin Oliphant, (8 October 1901 – 14 July 2000) was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and in the development of nuclear weapon ...

for the Chair of Physics at

Birmingham University The University of Birmingham (informally Birmingham University) is a Public university, public research university in Birmingham, England. It received its royal charter in 1900 as a successor to Queen's College, Birmingham (founded in 1825 as ...

. His job security in Oxford improved in 1936 when he was appointed Reader in

Thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed b ...

and a Student of Christ Church. Because he was naturalised, until 1940 he was prevented from working on

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

. Simon was among the 2,300 names of prominent persons listed on the

Nazi Nazism (), formally named National Socialism (NS; , ), is the far-right politics, far-right Totalitarianism, totalitarian socio-political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Germany. During H ...

s' Special Search List, of those who were to be arrested on the invasion of Great Britain and turned over to the

Gestapo The (, ), Syllabic abbreviation, abbreviated Gestapo (), was the official secret police of Nazi Germany and in German-occupied Europe. The force was created by Hermann Göring in 1933 by combining the various political police agencies of F ...

. Thus, his wife and children took up an offer to spend the war in Canada. Simon remained behind in Oxford. In 1940 in collaboration with

Nicholas Kurti Nicholas Kurti, () (14 May 1908 – 24 November 1998) was a Hungarian-born British physicist who lived in Oxford, UK, for most of his life. Career Born in Budapest, Kurti went to high school at the Minta Gymnasium, but due to anti-Jewish law ...

and

Heinrich Gerhard Kuhn Heinrich Gerhard Kuhn (10 March 1904 – 25 August 1994) was a British physicist. A graduate of the University of Göttingen, where he studied for his doctorate under the direction of James Franck, winner of the 1925 Nobel Prize for Physics, h ...

, he was commissioned by the

MAUD Committee The MAUD Committee was a British scientific working group formed during the Second World War. It was established to perform the research required to determine if an atomic bomb was feasible. The name MAUD came from a strange line in a telegram fr ...

to investigate the feasibility of separating uranium-235 by

. He initially adapted his wife's wire kitchen strainer to assist in this work before commissioning a membrane from ICI containing 160,000 holes to the square inch. His resulting conclusions on the separation of uranium isotopes was transferred to the

Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...

and was the basis of the process that produced sufficient U235 to make the atomic bomb. He spent the latter part of the Second World War at Los Alamos, returning in 1945 to Oxford to continue his low temperature research. He became a professor at the

and a Student of

Christ Church, Oxford Christ Church (, the temple or house, ''wikt:aedes, ædes'', of Christ, and thus sometimes known as "The House") is a Colleges of the University of Oxford, constituent college of the University of Oxford in England. Founded in 1546 by Henry V ...

in 1945. Upon the retirement of Lord Cherwell he became

Dr Lee's Professor of Experimental Philosophy The Dr Lee's Professorships are three named statutory professorships of the University of Oxford. They were created in 1919, and are named after Matthew Lee (1695–1755) who had endowed three readerships at Christ Church, Oxford, in the 19th cent ...

and head of the

in 1956, one month before his death from coronary disease.

Personal life

He married Charlotte Münchhausen in 1922. They had two daughters, Kathrin and Dorothee.Medawar & Pyke. Page 80.

Honours

* Fellow of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

, 1941 *

CBE The Most Excellent Order of the British Empire is a British order of chivalry, rewarding valuable service in a wide range of useful activities. It comprises five classes of awards across both civil and military divisions, the most senior two o ...

, 1946 *

Rumford Medal The Rumford Medal is an award bestowed by the Royal Society for "outstanding contributions in the field of physics". The award is named in honour of British scientist Sir Benjamin Thompson, Count Rumford, who is noted for his works on thermody ...

of the Royal Society, 1948 *

Knighted A knight is a person granted an honorary title of a knighthood by a head of state (including the pope) or representative for service to the monarch, the church, or the country, especially in a military capacity. The concept of a knighthood ...

, 1954

References

Bibliography

* * Clary, David C. (2022
''Schrödinger in Oxford''
World Scientific Publishing .

External links

Annotated bibliography for Francis Simon from the Alsos Digital Library for Nuclear Issues

Weintraub, B. Francis Simon. The Israel Chemist and Chemical Engineer, August 2018.
{{DEFAULTSORT:Simon, Francis 1893 births 1956 deaths Jewish emigrants from Nazi Germany to the United Kingdom Fellows of the Royal Society Fellows of Christ Church, Oxford Jewish scientists Knights Bachelor Commanders of the Order of the British Empire 20th-century British physicists 20th-century German physicists Recipients of the Iron Cross (1914), 1st class Dr Lee's Professors of Experimental Philosophy Jewish German physicists Members of the American Academy of Arts and Letters Fellows of the American Physical Society