Editing Stanisław Ulam (section)

==Return to academia==
[[File:Ulam 1.png|thumb|300px|When the positive integers are arrayed along the [[Ulam spiral]], prime numbers, represented by dots, tend to collect along diagonal lines.|alt=A lot of dots, but forming diagonal lines]]
During his years at Los Alamos, Ulam was a visiting professor at Harvard from 1951 to 1952, [[MIT]] from 1956 to 1957, the [[University of California, San Diego]], in 1963, and the [[University of Colorado at Boulder]] from 1961 to 1962 and 1965 to 1967. In 1967, the last of these positions became permanent, when Ulam was appointed Professor and Chairman of the Department of Mathematics at the University of Colorado. He kept a residence in Santa Fe, which made it convenient to spend summers at Los Alamos as a consultant.<ref name="AIP"/> He was an elected member of the [[American Academy of Arts and Sciences]], the United States [[National Academy of Sciences]], and the [[American Philosophical Society]].<ref>{{Cite web |title=Stanislaw Marcin Ulam |url=https://www.amacad.org/person/stanislaw-marcin-ulam |access-date=2022-09-21 |website=American Academy of Arts & Sciences |language=en}}</ref><ref>{{Cite web |title=S. M. Ulam |url=http://www.nasonline.org/member-directory/deceased-members/49612.html |access-date=2022-09-21 |website=www.nasonline.org}}</ref><ref>{{Cite web |title=APS Member History |url=https://search.amphilsoc.org/memhist/search?creator=Stanislaw+Ulam&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |access-date=2022-09-21 |website=search.amphilsoc.org}}</ref>

In Colorado, where he rejoined his friends Gamow, Richtmyer, and Hawkins, Ulam's research interests turned toward [[biology]]. In 1968, recognizing this emphasis, the [[University of Colorado School of Medicine]] appointed Ulam as Professor of Biomathematics, and he held this position until his death. With his Los Alamos colleague Robert Schrandt he published a report, "Some Elementary Attempts at Numerical Modeling of Problems Concerning Rates of Evolutionary Processes", which applied his earlier ideas on branching processes to evolution.<ref name='LA-4246'/> Another, report, with William Beyer, [[Temple F. Smith]], and M. L. Stein, titled "Metrics in Biology", introduced new ideas about numerical taxonomy and evolutionary distances.<ref name='LA-4973'/>

When he retired from Colorado in 1975, Ulam began to spend winter semesters at the [[University of Florida]], where he was a graduate research professor. In 1976, he was awarded the Commander's Cross with the Star of the [[Order of Polonia Restituta]] by the [[Polish government-in-exile]] in [[London]].<ref>{{cite web|url= http://eprints.hist.pl/336/1/1976-12-31_nr6.pdf|title= Komunikat o nadaniu Orderu Odrodzenia Polski|newspaper=Dziennik Ustaw Rzeczypospolitej Polskiej (s. 23, nr 6 z)|date=December 31, 1976|access-date= July 25, 2023|archive-date= April 24, 2018|archive-url= https://web.archive.org/web/20180424205236/http://eprints.hist.pl/336/1/1976-12-31_nr6.pdf|url-status= dead}}</ref> Except for [[sabbatical]]s at the [[University of California, Davis]] from 1982 to 1983, and at [[Rockefeller University]] from 1980 to 1984,<ref name="AIP"/> this pattern of spending summers in Colorado and Los Alamos and winters in Florida continued until Ulam died of an apparent heart attack in Santa Fe on 13 May 1984.<ref name='NYTIMES-OBIT'/>
[[Paul Erdős]] noted that "he died suddenly of heart failure, without fear or pain, while he could still prove and conjecture."<ref name="ERDOS"/> In 1987, [[Françoise Aron Ulam|Françoise Ulam]] deposited his papers with the [[American Philosophical Society]] Library in [[Philadelphia]].<ref name="PAPERS"/> She continued to live in Santa Fe until she died in 2011, at the age of 93. Both Françoise and her husband were buried with her family in [[Montparnasse Cemetery]] in Paris.<ref name='FULAMOBIT'/><ref name=RB/>