Leonard Ornstein mural, Oosterkade, Utrecht, 2021 - 1

Leonard Salomon Ornstein (November 12, 1880 in

Nijmegen Nijmegen (;; Spanish and it, Nimega. Nijmeegs: ''Nimwèège'' ) is the largest city in the Dutch province of Gelderland and tenth largest of the Netherlands as a whole, located on the Waal river close to the German border. It is about 6 ...

, the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

– May 20, 1941 in

Utrecht Utrecht ( , , ) is the List of cities in the Netherlands by province, fourth-largest city and a List of municipalities of the Netherlands, municipality of the Netherlands, capital and most populous city of the Provinces of the Netherlands, pro ...

, the Netherlands) was a Dutch

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

Biography

Ornstein studied theoretical physics with

Hendrik Antoon Lorentz Hendrik Antoon Lorentz (; 18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the Lorentz t ...

University of Leiden Leiden University (abbreviated as ''LEI''; nl, Universiteit Leiden) is a public research university in Leiden, Netherlands. The university was founded as a Protestant university in 1575 by William, Prince of Orange, as a reward to the city of Le ...

. He subsequently carried out Ph.D. research under the supervision of

Lorentz Lorentz is a name derived from the Roman surname, Laurentius, which means "from Laurentum". It is the German form of Laurence. Notable people with the name include: Given name * Lorentz Aspen (born 1978), Norwegian heavy metal pianist and keyboar ...

, concerning an application of the

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. It does not assume or postulate any natural laws, but explains the macroscopic be ...

of Gibbs to molecular problems. In 1914, Ornstein was appointed professor of physics, as successor of

Peter Debye Peter Joseph William Debye (; ; March 24, 1884 – November 2, 1966) was a Dutch-American physicist and physical chemist, and Nobel laureate in Chemistry. Biography Early life Born Petrus Josephus Wilhelmus Debije in Maastricht, Netherlands, D ...

, at

University of Utrecht Utrecht University (UU; nl, Universiteit Utrecht, formerly ''Rijksuniversiteit Utrecht'') is a public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2018, it had an enrollme ...

. Among his doctoral students was

Jan Frederik Schouten Jan Frederik Schouten (29 May 1910 – 12 August 1980) was a Dutch physicist, and Professor at the Eindhoven University of Technology, known for his contributions to biophysics. H. BoumaLevensbericht J.F. Schouten in: ''Jaarboek, 1980'', Amsterda ...

. In 1922, he became director of Physical Laboratory (''Fysisch Laboratorium'') and extended his research interests to experimental subjects. His precision measurements concerning intensities of spectral lines brought Physical Laboratory in the international limelight. Ornstein is also remembered for the Ornstein-Zernike theory (named after himself and Frederik Zernike) concerning correlation functions, and the Ornstein-Uhlenbeck process (named after Ornstein and

George Uhlenbeck George Eugene Uhlenbeck (December 6, 1900 – October 31, 1988) was a Dutch-American theoretical physicist. Background and education George Uhlenbeck was the son of Eugenius and Anne Beeger Uhlenbeck. He attended the Hogere Burgerschool (High S ...

), a

stochastic process In probability theory and related fields, a stochastic () or random process is a mathematical object usually defined as a family of random variables. Stochastic processes are widely used as mathematical models of systems and phenomena that appea ...

. Together with

Gilles Holst Gilles Holst (20 March 1886 – 11 October 1968) was a Dutch physicist, known worldwide for his invention in 1932 of the low-pressure sodium lamp. Early life His father was a manager of a shipyard. In 1904 he went to ETH Zurich to study mechanic ...

, director of

Philips Research Laboratories Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is ...

(''Philips Natuurkundig Laboratorium''), he was the driving force behind establishing the Dutch Physical Society ( Netherlands Physical Society, ''Nederlandse Natuurkundige Vereniging'', NNV) in 1921. From 1939 until November 1940 he was Chairman of this Society. From 1918 until 1922 Ornstein was Chairman of the Dutch Zionist Society (''Nederlandse Zionistische Vereniging''). In 1929, he became member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences ( nl, Koninklijke Nederlandse Akademie van Wetenschappen, abbreviated: KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed ...

. Immediately after the involvement of

the Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

in the

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

(see

Battle of the Netherlands The German invasion of the Netherlands ( nl, Duitse aanval op Nederland), otherwise known as the Battle of the Netherlands ( nl, Slag om Nederland), was a military campaign part of Battle of France, Case Yellow (german: Fall Gelb), the Nazi Ge ...

), a friend from the

United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

, the

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

Peter van de Kamp Piet van de Kamp (December 26, 1901 in Kampen (Overijssel), KampenLaurence W. Fredrick, Peter van de Kamp (1901–1995)', Publications of the Astronomical Socitiey of the Pacific 108:556–559, July 1996 – May 18, 1995 in Amsterdam), known a ...

, offered to bring Ornstein and his family to America. However, Ornstein did not accept this offer, since, as he put it, he would not leave his laboratory in Utrecht. Owing to his

Jewish Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...

heritage, Ornstein was summarily dismissed from the University in September, 1940. He was even barred from entering his own laboratory. In November, 1940, he was officially dismissed from the University. On November 29, 1940, Ornstein willingly withdrew his membership of the Dutch Physical Society. During this period he increasingly distanced himself from public life, to the degree that he no longer wished to receive guests at home. Ornstein died on May 20, 1941, six months after being barred from University. One of the five buildings of Department of Physics of University of Utrecht, the Ornstein Laboratorium, is named in his honor.

Publications

* ''Toepassing der statistische mechanica van Gibbs op moleculair-theoretische vraagstukken'', Phd Thesis 26 March 1908, in Dutch * ''Problemen der kinetische theorie van de stof'', 1915 * ''Strahlungsgesetz und Intensität von Mehrfachlinien'', 1924 * ''Intensität der Komponenten im Zeemaneffekt'', 1924 * ''On the theory of the Brownian motion'', 1930 * ''De beteekenis der natuurkunde voor cultuur en maatschappij'', 1932Speech in Dutch on the significance of physics to culture/civilisation and society:

References

External links

*Snelders H.A.M. (2007-02-01).
Ornstein, Leonard Salomon (1880-1941)
, in: ''Biografisch Woordenboek van Nederland''. Retrieved on 2007-03-30. ''(in

Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refer to: Places * Dutch, West Virginia, a community in the United States * Pennsylvania Dutch Country People E ...

)''.

* {{DEFAULTSORT:Ornstein, Leonard Salomon 1880 births 1941 deaths 20th-century Dutch physicists Probability theorists Leiden University alumni Academic staff of Utrecht University Jewish scientists Members of the Royal Netherlands Academy of Arts and Sciences People from Nijmegen Statistical physicists

Biography

Publications

See also

References

External links