Editing Lars Onsager (section)

===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/>