The Nobel Prize in Physics 1919
Born: 15 April 1874, Schickenhof, Germany
Died: 21 June 1957, Traunstein, West Germany (now Germany)
Affiliation at the time of the award: Greifswald University, Greifswald, Germany
Prize motivation: “for his discovery of the Doppler effect in canal rays and the splitting of spectral lines in electric fields”
Prize share: 1/1
Johannes Stark was born in Schickenhof in Bavaria and studied in Munich. He worked at a number of universities. During the 1920s he became an outspoken critic of modern physics, and in particular of Einstein. His criticism was not merely scientific, however, and was strongly influenced by anti-Semitism. After the Nazis took power in 1933 and until his retirement in 1939, he was head of Physikalische-Technische Bundesanstalt, today the National Metrology Institute of Germany. After World War II, he was charged and convicted for his collaboration with the Nazis.
If an electrical charge is placed between two metal plates in a glass tube filled with rarefied gas, charged atoms—ions—rush through the tube at high speed. Johannes Stark studied the light that the ions emitted. In 1905 he showed that a Doppler effect occurred: the frequency of the light was higher for light emitted in the direction of the atoms’ movement that for light emitted in the opposite direction. In 1914 Stark also discovered the Stark effect: lines in a spectrum are split up into several lines under the influence of an electrical field.