Jürgen Kurt Moser was born on July 4, 1928, in Königsberg, then part of Prussia. He could hardly have been born under more auspicious circumstances: the city is well known to mathematicians for the problem of the bridges of Königsberg, which inspired Euler and gave rise to two fields of mathematics, topology and graph theory.
The Nazis' rise to power in 1933, followed by the war, made Moser's youth difficult and perilous. Separated from his parents for a long time, he survived by a miracle and had to make his way from Königsberg to Göttingen, mostly on foot and under fire from Soviet soldiers and police forces. There, he was able to join the mathematics department in 1947. The mathematician Franz Rellich (1906–1955) took him under his wing and quickly recognized his talent: Moser completed his doctorate in 1952 with a thesis on the spectral theory of differential operators. Carl Siegel then sparked his interest in number theory and astronomy, particularly the n-body problem (the study of the behavior of n point masses, each pair subject to Newtonian attraction).
"Great self-confidence"
--------------------------------
Thanks to a prestigious American Fulbright scholarship, Moser spent 1953 at the Courant Institute in New York. His colleague there, Peter Lax, said of him: "We realized that he was truly special, a prince among men, a knight in shining armor… He worked hard and loved outdoor sports, beauty and music. He was an excellent companion. He loved adventure and testing his strength; he had great self-confidence." Another of his students, who later became his colleague, Paul Rabinowitz (born in 1939), said that he was "one of those rare people gifted with the ability to see mathematics as a whole. Moser was attentive to its connections with other sciences. His research had a profound impact on mathematics, astronomy and physics alike".
