Léon Rosenfeld (; 14 August 1904 in

Charleroi Charleroi ( , , ; wa, Tchålerwè ) is a city and a municipality of Wallonia, located in the province of Hainaut, Belgium. By 1 January 2008, the total population of Charleroi was 201,593.

– 23 March 1974) was a

Belgian Belgian may refer to: * Something of, or related to, Belgium * Belgians, people from Belgium or of Belgian descent * Languages of Belgium, languages spoken in Belgium, such as Dutch, French, and German *Ancient Belgian language, an extinct languag ...

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 cau ...

and

Marxist Marxism is a left-wing to far-left method of socioeconomic analysis that uses a materialist interpretation of historical development, better known as historical materialism, to understand class relations and social conflict and a dialecti ...

. Rosenfeld was born into a

secular Secularity, also the secular or secularness (from Latin ''saeculum'', "worldly" or "of a generation"), is the state of being unrelated or neutral in regards to religion. Anything that does not have an explicit reference to religion, either negativ ...

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 ...

family. He was a polyglot who knew eight or nine languages and was fluent in at least five of them. Rosenfeld obtained a

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * '' Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. al ...

at the

University of Liège The University of Liège (french: Université de Liège), or ULiège, is a major public university of the French Community of Belgium based in Liège, Wallonia, Belgium. Its official language is French. As of 2020, ULiège is ranked in the ...

in 1926, and he was a close collaborator of the physicist

Niels Bohr Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922 ...

. He did early work in quantum electrodynamics that predates by two decades the work by

Paul Dirac Paul Adrien Maurice Dirac (; 8 August 1902 – 20 October 1984) was an English theoretical physicist who is regarded as one of the most significant physicists of the 20th century. He was the Lucasian Professor of Mathematics at the Univer ...

and

Peter Bergmann Peter Gabriel Bergmann (24 March 1915 – 19 October 2002) was a German-American physicist best known for his work with Albert Einstein on a unified field theory encompassing all physical interactions. He also introduced primary and secondar ...

. Rosenfeld contributed to a wide range of physics fields, from statistical physics and quantum field theory to astrophysics. Along with

Frederik Belinfante Frederik Jozef Belinfante (6 January 1913 – 5 June 1991) was a Dutch physicist and a professor at Purdue University. He was a proponent of the hidden variable interpretation of quantum mechanics. Belinfante was born in the Hague and was a st ...

, he derived the

Belinfante–Rosenfeld stress–energy tensor In mathematical physics, the Belinfante– Rosenfeld tensor is a modification of the energy–momentum tensor that is constructed from the canonical energy–momentum tensor and the spin current so as to be symmetric yet still conserved. In a cl ...

. He also founded the journal ''

Nuclear Physics Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies t ...

'' and coined the term

lepton In particle physics, a lepton is an elementary particle of half-integer spin (spin ) that does not undergo strong interactions. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), and neutr ...

. In 1933, Rosenfeld married Yvonne Cambresier, who was one of the first women to obtain a Physics PhD from a European university. They had a daughter,

Andrée Rosenfeld Andrée Jeanne Rosenfeld FAHA (1934-2008) was an archaeologist specialising in rock art. Early life and education Rosenfeld was born in 1934 in Liège, Belgium, the daughter of the physicists Yvonne and Léon Rosenfelds. After the Second Worl ...

(1934–2008) and a son, Jean Rosenfeld.

Awards and honors

Rosenfeld held chairs at multiple universities: Liège,

Utrecht Utrecht ( , , ) is the fourth-largest city and a municipality of the Netherlands, capital and most populous city of the province of Utrecht. It is located in the eastern corner of the Randstad conurbation, in the very centre of mainland Net ...

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The ...

, and

Copenhagen Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan a ...

. In 1949 Léon Rosenfeld was awarded the Francqui Prize for Exact Sciences.

References

External links

*
Oral history interview transcript for Léon Rosenfeld on 3 September 1968, American Institute of Physics, Niels Bohr Library & Archives
1904 births 1974 deaths Belgian Jews Scientists from Charleroi Belgian physicists Jewish physicists University of Liège alumni Members of the German Academy of Sciences at Berlin {{Belgium-scientist-stub