Jens Lindhard (26 February 1922 – 15 October 1997) was a

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish a ...

physicist and professor at

Aarhus University Aarhus University ( da, Aarhus Universitet, abbreviated AU) is a public research university with its main campus located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Gr ...

working on

condensed matter physics Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases which arise from electromagnetic forces between atoms. More generally, the sub ...

statistical physics Statistical physics is a branch of physics that evolved from a foundation of statistical mechanics, which uses methods of probability theory and statistics, and particularly the Mathematics, mathematical tools for dealing with large populations ...

and

special relativity In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates: # The laws o ...

. He was the president of the

Royal Danish Academy of Sciences and Letters {{Infobox organization , name = The Royal Danish Academy of Sciences and Letters , full_name = , native_name = Det Kongelige Danske Videnskabernes Selskab , native_name_lang = , logo = Royal ...

between 1981 and 1988. He is known for the development of the

Lindhard theory In condensed matter physics, Lindhard theoryN. W. Ashcroft and N. D. Mermin, ''Solid State Physics'' (Thomson Learning, Toronto, 1976) is a method of calculating the effects of electric field screening by electrons in a solid. It is based on quant ...

, that describes the behaviour of metals under the influence of electromagnetic fields, named in his honour. He is also known for the development of channelling theory, to describe the path of a charged

particle In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object which can be described by several physical property, physical or chemical property, chemical ...

in a

crystalline solid A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

Early life

Jens Lindhard was born in Tystofte, Denmark in 1922, son of Erik and Agnes Lindhard. He was the youngest son of six, consisting of four girls and two boys. Jens' father was a professor at University of Copenhagen Faculty of Life Sciences but died young in 1928. Jens' older brother was a bomber in England and died during the

Invasion of Normandy Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful invasion of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Norm ...

. Jens went to school at the

Metropolitanskolen Metropolitanskolen ("The Metropolitan School") was a school in Copenhagen, Denmark founded in 1209 by the Bishop , and for centuries one of the most prestigious schools in the country. History The school was founded in 1209 next to the Church of ...

. Later, during his university studies, Jens joined the

Danish Brigade in Sweden The Danish Brigade in Sweden ( da, Den Danske Brigade i Sverige) or in short, the Danish Brigade (''Den Danske Brigade''/''DDB'') (also referred to as Danforce) was a military unit made up of Danish refugees during World War II. Trained and suppl ...

and also joined them back in the defence of the Danish-German border. He started his studies in physics at the

Niels Bohr Institute The Niels Bohr Institute (Danish: ''Niels Bohr Institutet'') is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics ...

and in 1945 he received a

Master of Science A Master of Science ( la, Magisterii Scientiae; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree in the field of science awarded by universities in many countries or a person holding such a degree. In contrast to ...

degree in physics from

University of Copenhagen The University of Copenhagen ( da, Københavns Universitet, KU) is a prestigious public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in ...

Research

During his university years, he worked under the supervision of Oskar Klein in

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

superconductivity Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

, publishing his first major work on the subject in 1944. Later he moved to work with

Rudolf Peierls Sir Rudolf Ernst Peierls, (; ; 5 June 1907 – 19 September 1995) was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied ...

in the

University of Birmingham , mottoeng = Through efforts to heights , established = 1825 – Birmingham School of Medicine and Surgery1836 – Birmingham Royal School of Medicine and Surgery1843 – Queen's College1875 – Mason Science College1898 – Mason Univers ...

. There, in 1954, he published the first description of the dielectric function of metals in the

linear response A linear response function describes the input-output relationship of a signal transducer such as a radio turning electromagnetic waves into music or a neuron turning synaptic input into a response. Because of its many applications in information ...

regime, today known as

. In 1950, he worked in close collaboration with

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. B ...

Blegdamsvej Blegdamsvej is a street in Copenhagen, Denmark, connecting Sankt Hans Torv in Nørrebro to Trianglen in Østerbro. The busy artery Fredensgade separates the Nørrebro and Østerbro sections of the street from each other. The north side of the st ...

on the penetration of particles in matter. There Lindhard, Morten Scharff and H. E. Schiøt developed what is now known as the (carrying their initials), which describes the penetration of low-energy ions. He also worked in fundamental problems related to statistical physics and relativity. As a teaching assistant, he helped to verify the formulas and problems in

Christian Møller Christian Møller (22 December 1904 in Hundslev, Als (island), Als14 January 1980 in Ordrup) was a Danish people, Danish chemist and physicist who made fundamental contributions to the theory of relativity, theory of gravitation and quantum chemi ...

's ''The Theory of Relativity.'' Later Lindhard would provide a solution to the controversy related to the transformation of temperature in

. Lindhard moved to

in 1957 in collaboration with experimentalist Karl Ove Nielsen, where he created and led a research group to study the penetration of charged particles in crystal lattices. During his time in Aarhus, Lindhard developed what is now known as the classical theory of channelling (sometimes also referred as Lindhard's theory) in continuum models in 1965.

Awards and membership

Jens Lindhard received several awards including: * the

Rigmor and Carl Holst-Knudsen Award for Scientific Research The Rigmor and Carl Holst-Knudsen Award for Scientific Research is one of Denmark's oldest and most prestigious science prizes. It was established in 1956, on the birthday of Carl Holst-Knudsen, who was at that time the Chairman of the Board at Aa ...

in 1965 * the

H. C. Ørsted Medal The H. C. Ørsted Medal is a medal for scientific achievement awarded by the Danish ''Selskabet for naturlærens udbredelse'' (The Society for the Dissemination of Natural Science). Named for the society's founder Hans Christian Ørsted, it is awa ...

in 1974 * the Danish Physical Society Physics award in 1988 * Honorary Doctorate degrees from

Odense University Odense University was a university in Odense, Denmark. It was established in 1966. In 1998, the university was merged with two other institutions to form the University of Southern Denmark. Its campus is now known as University of Southern Denmark ...

in 1996 and

Fudan University Fudan University () is a national public research university in Shanghai, China. Fudan is a member of the C9 League, Project 985, Project 211, and the Double First Class University identified by the Ministry of Education of China. It is als ...

, Shanghai, in 1997 Jens Linhard was member of the

and a member of the since 1962. We was president of the Royal Society from 1981–1988. He was also member of the

Koninklijke Hollandsche Maatschappij der Wetenschappen The Koninklijke Hollandsche Maatschappij der Wetenschappen (Royal Holland Society of Sciences and Humanities), located on the east side of the Spaarne in downtown Haarlem, Netherlands, was established in 1752 and is the oldest society for the sci ...

since 1984.

References

{{DEFAULTSORT:Lindhard, Jens 1922 births 1997 deaths 20th-century Danish physicists Condensed matter physicists Academic staff of Aarhus University University of Copenhagen alumni