2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/150712This is an article on the interaction between topology and physics which will appear in 1998 in a book called: A History of Topology, edited by Ioan James and published by Elsevier-North Holland.Plain TeX, 60 pages, postscript figures included. v2: Spelling of Königsberg corrected, thank you to all those who told me of this infelicity. v3: Some extra material added. I am much obliged to the numerous people who sent me emails about this article. v4: Some final additions. I am again much obliged to the numerous people who sent me emailsHigh Energy Physics - TheoryAlgebraic GeometryDifferential GeometryQuantum Algebratext