# Jens Lindhard

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Jens_Lindhard
> Markdown URL: https://mediated.wiki/source/Jens_Lindhard.md
> Source: https://en.wikipedia.org/wiki/Jens_Lindhard
> Source revision: 1301705948
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{short description|Danish theoretical physicist (1922–1997)}}
{{Infobox scientist
 |honorific_suffix = 
 |name          = 
 |image         = 
 |caption       = 
 |alt           = 
 |birth_name    = 
 |birth_date    = {{Birth date|df=y|1922|2|26}}
 |death_date    = {{nowr|{{Dath date and age|df=y|1997|10|15|1922|2|25}}}}
 |birth_place   = [Tystofte](/source/Tystofte), [Denmark](/source/Denmark)
 |death_place   = [Denmark](/source/Denmark)
 |resting_place = 
 |alma_mater    = 
 |known_for     = [Lindhard potential](/source/Channelling_(physics))<br>[Lindhard theory](/source/Lindhard_theory)<br>Lindhard–Scharff–Schiøt theory
 |spouse        = 
 |children      = 
 |awards        = [H. C. Ørsted Medal](/source/H._C._%C3%98rsted_Medal) {{small|(1974)}}<br>[Rigmor and Carl Holst-Knudsen Award for Scientific Research](/source/Rigmor_and_Carl_Holst-Knudsen_Award_for_Scientific_Research) {{small|(1965)}}
 |framestyle    = 
 |liststyle     = 
 |title         = 
 |field         = 
 |workplaces    = [University of Aarhus](/source/University_of_Aarhus)
 |style         = 
 |thesis_title  = 
 |thesis_url    = 
 |thesis_year   = 
 |doctoral_advisor  = 
 |academic_advisors = 
 |doctoral_students = 
 |notable_students  = 
 |influences    = 
 |influenced    = 
 |signature     =
}}
'''Jens Lindhard''' (26 February 1922 – 15 October 1997) was a [Danish](/source/Denmark) physicist and professor at [Aarhus University](/source/Aarhus_University) working on [condensed matter physics](/source/condensed_matter_physics), [statistical physics](/source/statistical_physics) and [special relativity](/source/special_relativity). He was the president of the [Royal Danish Academy of Sciences and Letters](/source/Royal_Danish_Academy_of_Sciences_and_Letters) between 1981 and 1988.<ref name=":0" />

He is known for the development of the [Lindhard theory](/source/Lindhard_theory), 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](/source/Channelling_(physics)) theory, to describe the path of a [charged](/source/Electric_charge) [particle](/source/particle) in a [crystalline solid](/source/crystalline_solid).

==Early life==
Jens Lindhard was born in [Tystofte](/source/Tystofte), Denmark in 1922, son of Erik and Agnes Lindhard.<ref name=":0">{{Cite web |last=Andersen |first=Jens Ulrik |date=1997 |title=Nekrolog |url=https://phys.au.dk/en/om-instituttet/historie/jens-lindhard-1922-1997/nekrolog |access-date=2022-09-09 |website=Aarhus Universitet – Department of Physics and Astronomy |language=da}}</ref> He was the youngest son of six, consisting of four girls and two boys.<ref name=":0" /> Jens' father was a professor at [University of Copenhagen Faculty of Life Sciences](/source/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](/source/Invasion_of_Normandy).<ref name=":0" />

Jens went to school at the [Metropolitanskolen](/source/Metropolitanskolen).<ref name=":0" /> 

Later, during his university studies, Jens joined the [Danish Brigade in Sweden](/source/Danish_Brigade_in_Sweden) and also joined them back in the defence of the Danish-German border.<ref name=":0" />

He started his studies in physics at the [Niels Bohr Institute](/source/Niels_Bohr_Institute) and in 1945 he received a [Master of Science](/source/Master_of_Science) degree in physics from [University of Copenhagen](/source/University_of_Copenhagen).<ref name="PT">{{Cite journal |last1=Andersen |first1=Jens Ulrik |last2=Sigmund |first2=Peter |date=September 1998 |title=Jens Lindhard |journal=Physics Today |language=en |volume=51 |issue=9 |pages=89–90 |bibcode=1998PhT....51i..89A |doi=10.1063/1.882460 |issn=0031-9228 |doi-access=}}</ref> 

== Research ==
During his university years, he worked under the supervision of [Oskar Klein](/source/Oskar_Klein) in [Sweden](/source/Sweden) on [superconductivity](/source/superconductivity), publishing his first major work on the subject in 1944.<ref name="PT" /><ref name=":0" /> 

Later he moved to work with [Rudolf Peierls](/source/Rudolf_Peierls) in the [University of Birmingham](/source/University_of_Birmingham).<ref name=":0" /> There, in 1954, he published the first description of the dielectric function of metals in the [linear response](/source/linear_response) regime, today known as [Lindhard theory](/source/Lindhard_theory).<ref name=":0" /><ref>{{cite journal|last=Lindhard|first=Jens|date=1954|title=On the properties of a gas of charged particles|url=http://gymarkiv.sdu.dk/MFM/kdvs/mfm%2020-29/mfm-28-8.pdf|journal=Danske Matematisk-fysiske Meddelelser|volume=28|issue=8|pages=1–57|access-date=2016-09-28}}</ref>

In 1950, he worked in close collaboration with [Niels Bohr](/source/Niels_Bohr) in [Blegdamsvej](/source/Blegdamsvej) on the penetration of particles in matter.<ref name="PT" /><ref name=":0" /> There Lindhard, Morten Scharff and H. E. Schiøt developed what is now known as the {{ill|LSS theory|de|LSS-Theorie}} (carrying their initials), which describes the penetration of low-energy ions.<ref name="PT" /> 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](/source/Christian_M%C3%B8ller)'s ''The Theory of Relativity.<ref name=":0" />''<ref>{{Cite book |last=Moller. C |url=http://archive.org/details/theoryofrelativi029229mbp |title=The Theory Of Relativity |date=1952 |publisher=At The Clarendon Press |others=Osmania University, Digital Library Of India}}</ref> Later Lindhard would provide a solution to the controversy related to the transformation of temperature in [special relativity](/source/special_relativity).<ref name="PT" /><ref name=":0" /><ref>{{Cite journal |last=Lindhard |first=J. |date=1968-06-05 |title=Temperature in special relativity |url=https://dx.doi.org/10.1016/0031-8914%2868%2990011-6 |journal=Physica |language=en |volume=38 |issue=4 |pages=635–640 |doi=10.1016/0031-8914(68)90011-6 |issn=0031-8914|url-access=subscription }}</ref> 

Lindhard moved to [Aarhus University](/source/Aarhus_University) 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.<ref name="PT" /> During his time in Aarhus, Lindhard developed what is now known as the classical theory of [channelling](/source/Channelling_(physics)) (sometimes also referred as Lindhard's theory) in continuum models in 1965.<ref>{{Cite journal |last=Davies |first=J A |date=1983-09-01 |title=The Channeling Phenomenon- and Some of Its Applications |url=https://iopscience.iop.org/article/10.1088/0031-8949/28/3/006 |journal=Physica Scripta |language=en |volume=28 |issue=3 |pages=294–302 |doi=10.1088/0031-8949/28/3/006 |s2cid=250837019 |issn=0031-8949|url-access=subscription }}</ref>

== Awards and membership ==
Jens Lindhard received several awards including:<ref name=":0" />
* the [Rigmor and Carl Holst-Knudsen Award for Scientific Research](/source/Rigmor_and_Carl_Holst-Knudsen_Award_for_Scientific_Research) in 1965
* the [H. C. Ørsted Medal](/source/H._C._%C3%98rsted_Medal) in 1974
* the [Danish Physical Society](/source/Danish_Physical_Society) Physics award in 1988
* Honorary Doctorate degrees from [Odense University](/source/Odense_University) in 1996 and [Fudan University](/source/Fudan_University), Shanghai, in 1997
Jens Linhard was member of the [Royal Danish Academy of Sciences and Letters](/source/Royal_Danish_Academy_of_Sciences_and_Letters) and a member of the {{ill|Akademiet for de tekniske Videnskaber|da}} since 1962. We was president of the Royal Society from 1981–1988. He was also member of the ''[Koninklijke Hollandsche Maatschappij der Wetenschappen](/source/Koninklijke_Hollandsche_Maatschappij_der_Wetenschappen)'' since 1984.<ref name=":0" />

==References==
{{Reflist}}
{{Authority control}}
{{DEFAULTSORT:Lindhard, Jens}}
Category:1922 births
Category:1997 deaths
Category:20th-century Danish physicists
Category:Condensed matter physicists
Category:Academic staff of Aarhus University
Category:University of Copenhagen alumni

---
Adapted from the Wikipedia article [Jens Lindhard](https://en.wikipedia.org/wiki/Jens_Lindhard) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Jens_Lindhard?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.