8.1 Other ideas that carry his name

From 1965 Ulam chaired mathematics at the University of Colorado in Boulder. He was also Graduate Research Professor at the University of Florida from 1974 to 1984, and at his death he was professor of biomathematics at Colorado [1, 2, 3]. His books include A Collection of Mathematical Problems (1960) and the memoir Adventures of a Mathematician (1976) [1].

The Borsuk–Ulam theorem. In plain words: any continuous map from a sphere to the plane sends some pair of opposite points to the same point. Karol Borsuk proved it in a 1933 paper, and a footnote of that paper says "Dieser Satz wurde als Vermutung von St. Ulam aufgestellt": the theorem was stated as a conjecture by Ulam [4].

Hyers–Ulam stability. A stability property of functional equations is named after Hyers and Ulam. D. H. Hyers published "On the Stability of the Linear Functional Equation" in the Proceedings of the National Academy of Sciences in 1941 [5].

Project Orion. Ulam, with C. J. Everett, proposed the "Orion" plan. Their Los Alamos report LAMS-1955, "On a method of propulsion of projectiles by means of external nuclear explosions", is dated August 1955 [1, 6].

Problem 38. Ulam's Problem 38 of the Scottish Book, about chains of friends, is seen today as a forerunner of random graph theory [7].

Ulam died on 13 May 1984 in Santa Fe, New Mexico [1, 2, 8]. His papers are held by the American Philosophical Society, Mss.Ms.Coll.54 [9].

Sources

1. MacTutor, "Stanisław Marcin Ulam", https://mathshistory.st-andrews.ac.uk/Biographies/Ulam/
2. IEEE Computer Society, Computer Pioneers, "S. M. Ulam", https://history.computer.org/pioneers/ulam.html
3. University of Florida, Department of Mathematics, "Ulam Colloquium", https://math.ufl.edu/research/ulam-colloquium/
4. K. Borsuk, "Drei Sätze über die n-dimensionale euklidische Sphäre", Fundamenta Mathematicae 20 (1933) 177–190, doi:10.4064/fm-20-1-177-190, https://doi.org/10.4064/fm-20-1-177-190
5. D. H. Hyers, "On the Stability of the Linear Functional Equation", PNAS 27(4) (1941) 222–224, doi:10.1073/pnas.27.4.222, https://doi.org/10.1073/pnas.27.4.222
6. LANL report library record, LAMS-1955, "On a method of propulsion of projectiles by means of external nuclear explosions, part I", Aug. 1955, mirrored at, https://sgp.fas.org/othergov/doe/lanl/lib-www/la-pubs/00350011.html
7. S. Domoradzki, M. Stawiska, M. Zarichnyi, "90+ years of the Scottish Book", arXiv:2603.27867 (2026), https://arxiv.org/abs/2603.27867
8. LANL Center for Nonlinear Studies, "Stanislaw Marcin Ulam", https://cnls.lanl.gov/External/Ulam/Biography.html
9. American Philosophical Society, Stanislaw M. Ulam Papers, Mss.Ms.Coll.54, https://search.amphilsoc.org/collections/style/pdfoutput/Mss.Ms.Coll.54-ead.pdf