After the wars
The period immediately before the outbreak of World War II and especially during the war proved difficult for the ETH. In the wake of the global economic crisis the ETH mainly experienced financial difficulties. Switzerland's forced isolation resulted in an almost complete standstill of international scientific exchange; even correspondence with the US for instance was blocked for several years.
Beno Eckmann founds the Research Institute for Mathematics
With the end of the war, and especially in the 1950s and 1960s the emphasis at the ETH Zurich shifted away from teaching and training towards a far greater focus on research. This was reflected in the strong expansion of theoretical mathematics, where Beno Eckmann (1917-2008, in office 1948-1984) played an important role. As a student of Heinz Hopf, he supervised the field of algebraic topology and algebra together with Hopf. In 1964, he founded the Forschungsinstitut für Mathematik (FIM). The FIM quickly established itself as an important institution where ETH mathematicians could get in contact with top level mathematical research, represented by the many international guests at the FIM.
Expansion of applied mathematics
In the 1950s and 1960s, a number of new developments appeared in mathematics. They included statistics and probability theory, applied mathematics, the use of electronic calculators, the discipline of operations research, as well as the logic and set theory. Not least because of generous general conditions and its own initiative could the ETH absorb these new areas rather quickly.
Computer by Konrad Zuse
An illustrative example here is Eduard Stiefel (1909-1978, in office 1943-1978) in applied mathematics. As a student of Heinz Hopf in algebraic topology, Stiefel increasingly turned his attention towards applied mathematics already in the 1940s. Shortly after the end of the war, he managed to get the world's first commercial digital computer Z4 constructed by Konrad Zuse from Germany to Zurich. Later he became head of the newly formed Seminar for Applied Mathematics (SAM), which also operated ERMETH, a computer built at the ETH. Computer science seceded in 1981 as a separate division. The field of applied mathematics remained within the SAM in its original location and expanded in scope over the years.
Logic and set theory
The area of logic and set theory was covered by Paul Bernays (1888-1977, in office 1945-1959), Ernst Specker (1920-2011, in office 1955-1987) and Erwin Engeler (1930-, in office from 1972-1997). Being Jewish, Bernays lost his job in Göttingen when the National Socialists came to power. He returned to Switzerland, where he had been employed as senior lecturer at the University of Zurich (1912-1919) before going to Göttingen, and subsequently worked as a lecturer at the ETH. Specker did his doctorate under Heinz Hopf in algebraic topology, but afterwards devoted himself entirely to logic and set theory.
On 1st January 1967 the Institute for Operations Research (IFOR) was established by the board of the ETH Zurich. Franz Weinberg (1924-2016, in office 1964-1990) was appointed as the first director, and shortly afterwards received support from Hans P. Kuenzi (1924-2004, in office 1966-1972).
Statistics and insurance mathematics
The field of statistics and probability theory and its neighbouring area of insurance mathematics were supervised for a longer period by Walter Saxer (1896-1975, in office 1927-1966). Saxer developed the mathematical basis for the introduction of the federal retirement and survivors' insurance (AHV) in the 1940s, and advised the administration and political committees on the subject. In line with their increased significance, statistics and probability theory were extended at the ETH in the early 1960s. Peter Huber (1934-, in office 1964-1979), Hans Bühlmann (1930-, in office 1966-1997) and others were appointed for this task. From their activities the Seminar für Statistik (SfS) emerged.