Portrait of Rudolf Hertz Henrich

Rudolf Hertz Henrich (February 22, 1857, Hamburg — January 1, 1894, Bonn) was a German physicist of Jewish origin. He graduated from the University of Berlin, where he was taught by Herman von Helmholtz and Gustav Kirchhoff. From 1885 to 1889 he was a professor of physics at the University of Karlsruhe. Since 1889 he has been a professor of physics at the University of Bonn.
Hertz introduced into science the concept of a physical picture of the world.

Since 1933, Hertz has been the unit of measurement of the hertz frequency, which is part of the International System of Units (SI).

Although Hertz was a Lutheran, his portrait was taken by the Nazis from his place of honor in Hamburg City Hall because he is “partly of Jewish origin”.