Johann Radon

16th December 1887 to 25th May 1956

Johann Radon, signature, University of Breslau, 1935

Mathematician Johann Radon was born in Austria-Hungary. He received his doctoral degree at the University of Vienna in 1910 for his work on the calculus of variations: ‘Über das Minimum des Integrals ∫S1S0F(x, y, theta, kappa)ds’.

Next, Radon worked at the universities of Göttingen, Vienna and Hamburg, among others, gaining a professorship at Breslau from 1928 to 1945.

During the early years in which my father was a student at Breslau, Radon was director of a mathematics seminar series, with an address at Leerbeutelstraße.

Johann Radon, University of Breslau handbook, 1930-1931

Radon taught on the same pure mathematics course as his colleague Professor Rademacher, and finally in that academic year, Radon gave a number of classes in the Astronomy and mathematics module, including differential geometry on Tuesdays, Wednesdays and Thursdays, from 9am to 10am; a mathematics seminar on Tuesdays from 5pm to 7pm; differential equations from Tuesdays to Fridays, from 8am to 9am; and differential equation exercises on Fridays from 6pm to 7pm.

According to the 1935 to 1936 handbook, Radon’s address was now Wagnerstraße.

Wagnerstraße, Breslau 1931 Source: fotopolska online

As he was still teaching at this point, Johann Radon will have taken the Oath of Loyalty to the National Socialist party after 1933.

Radon is listed in the handbook for this academic year as being Director of Mathematics, and he gave mathematics seminars. He continued to teach on the pure mathematics course, and on the Mathematics and Astrology module again, teaching differential and integral equations, and advanced mathematics, and giving private tutorials to advanced students.

Johann Radon, University of Breslau handbook, 1935

Radon is known for a number of  contributions to mathematics – real analysis, functional analysis, the calculus of variations, and differential geometry. He may be best know for the Radon-Nikodym theorem on conditions for the existence of a density function (or derivative) of one measure with respect to another.

At the end of the war, Radon and the remaining members of the mathematics department of Breslau were moved away from the advancing troops of the USSR. Anecdotally, with no books or materials, Radon apparently still gave his lecture from memory – on complex analysis.

Radon was Chair of the mathematics and physics section of the Austrian Academy of Science from 1952 to 1956. He died in Vienna in 1956.


All black and white extracts on this page are from the 'Vorlesungs und Personal Verzeichnis der Schlesischen Friedrich Wilhelms Universität zu Breslau Winter Semester 1930/1931', and the equivalent handbook for 1935-1936, available online at the University of Wrocław.

The map extract is from the excellent fotopolska.eu.