Editing Lars Onsager (section)

==Career and research==
In 1925 he arrived at a correction to the [[Debye–Hückel equation|Debye-Hückel theory]] of [[electrolyte|electrolytic]] [[Solution (chemistry)|solution]]s, to specify [[Brownian movement]] of [[ion]]s in solution, and during 1926 published it. He traveled to [[Zürich]], where [[Peter Debye]] was teaching, and confronted Debye, telling him his theory was wrong. He impressed Debye so much that he was invited to become Debye's assistant at the [[ETH Zürich|Eidgenössische Technische Hochschule (ETH)]], where he remained until 1928.<ref>{{cite web|url=https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1968/onsager-bio.html |title=Lars Onsager - Biographical |website=Nobelprize.org |access-date=2016-03-07}}</ref>

===Johns Hopkins University===
In 1928 he went to the United States to take a faculty position at the [[Johns Hopkins University]] in [[Baltimore, Maryland]]. At JHU he had to teach freshman classes in [[chemistry]], and it quickly became apparent that, while he was a genius at developing theories in physical chemistry, he had little talent for teaching. He was dismissed by JHU after one semester.<ref name=":1">{{Cite journal |last1=Christopher Longuet-Higgins |first1=H. |last2=Fisher |first2=Michael E. |date=1995-01-01 |title=Lars Onsager: November 27, 1903–October 5, 1976 |url=https://doi.org/10.1007/BF02183371 |journal=Journal of Statistical Physics |language=en |volume=78 |issue=1 |pages=605–640 |doi=10.1007/BF02183371 |bibcode=1995JSP....78..605C |issn=1572-9613}}</ref>

=== Brown University===
On leaving JHU, he accepted a position (involving the teaching of [[statistical mechanics]] to graduate students in chemistry) at [[Brown University]] in [[Providence, Rhode Island]], where it became clear that he was no better at teaching advanced students than freshmen, but he made significant contributions to statistical mechanics and [[thermodynamics]]. His graduate student [[Raymond Fuoss]] worked under him and eventually joined him on the Yale chemistry faculty. His statistical mechanics course was nicknamed "Sadistical Mechanics" by the students.<ref name=":0">{{Cite journal |last1=Christopher Longuet-Higgins |first1=H. |last2=Fisher |first2=Michael E. |date=1995-01-01 |title=Lars Onsager: November 27, 1903–October 5, 1976 |url=https://doi.org/10.1007/BF02183371 |journal=Journal of Statistical Physics |language=en |volume=78 |issue=1 |pages=605–640 |doi=10.1007/BF02183371 |bibcode=1995JSP....78..605C |issn=1572-9613}}</ref>

His research at Brown was concerned mainly with the effects on [[diffusion]] of [[temperature gradient]]s, and produced the [[Onsager reciprocal relations]], a set of equations published in 1929 and, in an expanded form, in 1931, in [[statistical mechanics]] whose importance went unrecognized for many years. However, their value became apparent during the decades following [[World War II]], and by 1968 they were considered important enough to gain Onsager that year's [[Nobel Prize in Chemistry]].

In 1933, when the [[Great Depression]] limited Brown's ability to support a faculty member who was only useful as a researcher and not a teacher, he was let go by Brown. He traveled to [[Austria]] to visit [[electrochemistry|electrochemist]] [[Hans Falkenhagen]]. He met Falkenhagen's sister-in-law, Margrethe Arledter. They were married on September 7, 1933, and had three sons and a daughter.<ref>{{cite web |date=1991-12-06 |title=Lars Onsager – Norsk biografisk leksikon |url=https://nbl.snl.no/Lars_Onsager |access-date=2016-03-07 |website=Nbl.snl.no}}</ref>

===Yale University===
After the trip to [[Europe]], he was hired by [[Yale University]], where he remained for most of the rest of his life, retiring in 1972.<ref>{{cite web |title=Lars Onsager |url=http://www.nndb.com/people/579/000100279/ |access-date=2016-03-07 |website=Nndb.com}}</ref>

At Yale, he had been hired as a postdoctoral fellow, but it was discovered that he had never received a [[Doctor of Philosophy|Ph.D.]]<ref name="PhysToday" /> While he had submitted an outline of his work in reciprocal relations to the [[Norwegian Institute of Technology]], they had decided it was too incomplete to qualify as a doctoral dissertation. He was told that he could submit one of his published papers to the Yale faculty as a dissertation, but insisted on doing a new research project instead. His dissertation laid the mathematical background for his interpretation of deviations from Ohm's law in weak electrolytes.<ref>{{Cite journal |last=Onsager |first=Lars |date=1934-09-01 |title=Deviations from Ohm's Law in Weak Electrolytes |url=https://pubs.aip.org/jcp/article/2/9/599/201481/Deviations-from-Ohm-s-Law-in-Weak-Electrolytes |journal=The Journal of Chemical Physics |language=en |volume=2 |issue=9 |pages=599–615 |doi=10.1063/1.1749541 |bibcode=1934JChPh...2..599O |issn=0021-9606}}</ref> It dealt with the solutions of the [[Mathieu function|Mathieu equation]] of period <math>4\pi</math> and certain related functions and was beyond the comprehension of the [[chemistry]] and [[physics]] faculty. Only when some members of the [[mathematics]] department, including the chairman [[Einar Hille]] (who also liked ''A Course of Modern Analysis''), insisted that the work was good enough that ''they'' would grant the doctorate if the chemistry department would not, was he granted a Ph.D. in chemistry in 1935.

Even before the dissertation was finished, he was appointed assistant professor in 1934,<ref name="PhysToday" /> and promoted to associate professor in 1940. He quickly showed at Yale the same traits he had at JHU and Brown: he produced brilliant theoretical research, but was incapable of giving a lecture at a level that a student (even a graduate student) could comprehend. He was also unable to direct the research of graduate students, except for the occasional outstanding one.<ref>{{cite web |url=http://emur.org/chemists/lars-onsager.htm |title=Famous Chemists Web Site |website=Emur.org |access-date=2016-03-07 |url-status=dead |archive-url=https://web.archive.org/web/20160304065912/http://emur.org/chemists/lars-onsager.htm |archive-date=2016-03-04 }}</ref> His two courses on statistical mechanics were nicknamed "Advanced Norwegian I" and "Advanced Norwegian II" for being incomprehensible.<ref name=":0" />

During the late 1930s, Onsager researched the [[dipole]] theory of [[dielectric]]s, making improvements for another topic that had been studied by Peter Debye. However, when he submitted his paper to a journal that Debye edited in 1936, it was rejected. Debye would not accept Onsager's ideas until after [[World War II]]. During the 1940s, Onsager studied the [[statistical mechanics|statistical-mechanical theory]] of [[phases of matter|phase]] transitions in [[solid]]s, deriving a mathematically elegant theory which was enthusiastically received. In what is widely considered a tour de force of mathematical physics, he obtained the exact solution for the two dimensional [[Ising model]] in zero field in 1944.<ref>{{cite web |url=http://www.aip.org/history/acap/biographies/bio.jsp?onsagerl |title=Lars Onsager &#124; Array of Contemporary American Physicists |website=Aip.org |access-date=2016-03-07 |url-status=dead |archive-url=https://web.archive.org/web/20160308131122/https://www.aip.org/history/acap/biographies/bio.jsp?onsagerl |archive-date=2016-03-08 }}</ref><ref>{{cite web |url=http://faculty.cua.edu/may/ |title=index.htm |website=Faculty.cua.edu |access-date=2016-03-07 |url-status=dead |archive-url=https://web.archive.org/web/20150624044914/http://faculty.cua.edu/may/ |archive-date=2015-06-24 }}</ref><ref>{{Cite journal |doi = 10.1103/PhysRev.65.117|title = Crystal Statistics. I. A Two-Dimensional Model with an Order-Disorder Transition|journal = Physical Review|volume = 65|issue = 3–4|pages = 117–149|year = 1944|last1 = Onsager|first1 = Lars|bibcode = 1944PhRv...65..117O}}</ref>

In 1960 he was awarded an [[honorary degree]], doctor techn. honoris causa, at the [[Norwegian Institute of Technology]], later part of [[Norwegian University of Science and Technology]].<ref>{{cite web |url=http://www.ntnu.edu/phd/honorary-doctors|title=Honorary doctors at NTNU|publisher=Norwegian University of Science and Technology|language=en|website=Ntnu.edu|access-date=2016-03-07}}</ref>

In 1945, Onsager was [[naturalization|naturalized]] as an American citizen, and the same year he was awarded the title of ''J. Willard Gibbs Professor of Theoretical Chemistry''. This was particularly appropriate because Onsager, like [[Willard Gibbs]], had been involved primarily in the application of [[mathematics]] to problems in [[physics]] and [[chemistry]] and, in a sense, could be considered to be continuing in the same areas Gibbs had pioneered.
In 1947, he was elected to the [[United States National Academy of Sciences|National Academy of Sciences]],<ref>{{Cite web |title=Lars Onsager |url=http://www.nasonline.org/member-directory/deceased-members/20001605.html |access-date=2022-12-07 |website=www.nasonline.org}}</ref> the [[American Academy of Arts and Sciences]] in 1949,<ref>{{Cite web |title=Lars Onsager |url=https://www.amacad.org/person/lars-onsager |access-date=2022-12-07 |website=American Academy of Arts & Sciences |language=en}}</ref> and in 1950 he joined the ranks of [[Alpha Chi Sigma]].

After [[World War II]], Onsager researched new topics of interest. 
He proposed a theoretical explanation of the [[superfluidity|superfluid]] properties of [[liquid]] [[helium]] in 1949; two years later the [[physicist]] [[Richard Feynman]] independently proposed the same theory. He also worked on the theories of [[liquid crystal]]s and the electrical properties of [[ice]]. While on a [[Fulbright scholarship]] to the [[University of Cambridge]], he worked on the magnetic properties of [[metal]]s. He developed important ideas on the quantization of magnetic flux in metals. He was awarded the [[Lorentz Medal]] in 1958, [[Willard Gibbs Award]] in 1962,<ref>{{cite web|url=http://chicagoacs.org/content.php?page=Willard_Gibbs_Award |title=Willard Gibbs Award |website=Chicagoacs.org |access-date=2016-03-07}}</ref> and the [[Nobel Prize in Chemistry]] in 1968. He was elected a member of the [[American Philosophical Society]] in 1959 and a [[List of Fellows of the Royal Society elected in 1975|Foreign Member of the Royal Society (ForMemRS) in 1975]].<ref>{{Cite web |title=APS Member History |url=https://search.amphilsoc.org/memhist/search?creator=Lars+Onsager&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |access-date=2022-12-07 |website=search.amphilsoc.org}}</ref><ref name=formemrs/>

===After Yale===
[[Image:Kirkwood onsager.jpg|thumb|right|Graves of Onsager and Kirkwood]]
In 1972 Onsager retired from Yale and became emeritus. He then became a member of the [[Center for Theoretical Studies, University of Miami]], and was appointed Distinguished University Professor of Physics.<ref>{{cite book |author=National Academy of Sciences |chapter-url=http://www.nap.edu/openbook.php?record_id=6061&page=218  |doi=10.17226/6061 |access-date=2016-03-07|year=1991 |isbn=978-0-309-07865-8 |title=Biographical Memoirs |chapter=Lars Onsager|volume=60 |publisher=The National Academies Press}}</ref> At the [[University of Miami]] he remained active in guiding and inspiring postdoctoral students as his teaching skills, although not his lecturing skills, had improved during the course of his career. He developed interests in semiconductor physics, biophysics and radiation chemistry. However, his death came before he could produce any breakthroughs comparable to those of his earlier years.