Johannes Stark Biography

Johannes Stark's life can be divided into two fairly distinct and contrasting halves. During the earlier period, he demonstrated unusual skills as an experimentalist and won acclaim as a brilliant physicist, holding posts at universities throughout Germany. Founder and editor of the prestigious Jahrbuch der Radioaktivität und Elektronik (Yearbook of Radioactivity and Electronics ), he is credited with discovering the Doppler effect in canal rays, and the splitting of the spectral lines of hydrogen by means of an external electrical field, a phenomenon now known as the Stark effect. For these discoveries, Stark received the 1919 Nobel Prize in physics. After 1913, however, Stark began to withdraw from the scientific community and to ally himself with Adolf Hitler's program of National Socialism. Along with Philipp von Lenard , Stark called for a "purification" of German science, an adoption of a non-Jewish "Aryan science." He failed to receive the recognition he sought in the political arena and eventually found himself ostracized by fellow scientists in Germany and throughout the world.

Stark was born on April 15, 1874, in Schickenhof, Bavaria. Raised on a farm, he attended local schools in Bayreuth and Regensburg. In 1894, he entered the University of Munich as a science major, earning his doctorate in 1897 for a dissertation entitled "Investigations on Lampblack." He then accepted a post as assistant to Eugen Lommel at Munich, a position he held for the next three years. In the spring of 1900, Stark moved to the University of Göttingen as assistant to Eduard Riecke, and was appointed privatdozent in 1903.

Stark Discovers the Doppler Effect in Canal Rays

During his tenure at Göttingen, Stark made the first of his important discoveries, the Doppler effect in canal rays. The Doppler effect is the change in frequency that occurs in a wave as its source advances toward or retreats from an observer. Wavelengths shorten as they approach, producing a higher pitch or frequency, and lengthen as they recede, producing a lower pitch. The apparent change in pitch of a train whistle as it passes an observer is a familiar example of the Doppler effect. The Doppler effect had been predicted by Johann Christian Doppler in 1842, and, by 1900, had been observed by the American astronomer Edwin Hubble in the red shift of galaxies, though no terrestrial example had yet been described. Stark decided that an appropriate way to observe the Doppler effect in the laboratory was with canal rays, beams of positively charged particles generated in a vacuum tube. In 1905, Stark used canal rays of hydrogen atoms to conduct the experiment and observed the predicted Doppler effect in hydrogen spectral lines--as they approached they reached higher frequencies, the violet end of the spectrum, and, like Hubble's galaxies, they shifted to the red, or lower, frequencies as they receded.

In 1906, Stark was appointed lecturer in applied physics and photography at the Technical College in Hannover. During his three-year tenure there, Stark was continuously on bad terms with his superior, Julius Brecht. Finally, in 1909, Stark accepted an appointment as professor at the Technical College at Aachen, where he remained for eight years.

Observes the Splitting of Spectral Lines

Since his days at Hannover, Stark had been thinking about a problem originally suggested by the work of the Dutch physicist Pieter Zeeman . In 1896, Zeeman had observed that the presence of a magnetic field can cause an element's spectral lines to split. This analogy to an electric field was too obvious for physicists to miss, and while a number of them had tried in the first decade of the twentieth century to produce this effect, none were successful. But in 1913, Stark succeeded in splitting spectral lines in an electric field. He placed a third electrode a few centimeters from the cathode in a vacuum tube and applied a potential difference of 20,000 volts between the two. When canal rays were generated in the tube, Stark was able to observe the splitting of the spectral lines of hydrogen gas, a phenomenon that is now known as the Stark effect. For his work on the Doppler and Stark effects, Stark was awarded the 1919 Nobel Prize in physics. In addition, he received the Baumgartner Prize of the Vienna Academy of Sciences in 1910, the Vahlbruch Prize of the Göttingen Academy of Sciences in 1914, and the Matteuci Gold Medal of the National Academy of Sciences of Italy.

Shifts from Scientific to Political Activities

After 1913, Stark slowly fell out of the mainstream of scientific research. Scholars have suggested a number of reasons for this change. A major factor seems to have been his inability to get along with other scientists and subsequent failure to receive an appropriate academic appointment. In 1917, he accepted a post as professor of physics at the University of Greifswald. He seems to have been happy in the conservative climate of this university, but decided to leave in 1920 to accept a similar post at the University of Würzburg. Stark was much less comfortable there, as his colleagues and superiors found a number of reasons to object to his presence, including his use of Nobel Prize money to finance the construction of a new ceramics factory. Although he devoted an increasing amount of time and attention to the factory, it eventually failed. Stark's colleagues found his attention to non-academic concerns ethically questionable. In addition, Stark's increasingly conservative political views were not well received in the liberal environment of Würzburg.

By 1922, Stark had become so uncomfortable at Würzburg that he resigned his post. He then became increasingly active politically in opposition to the post-World War I Weimar Republic, and in efforts to establish conservative, anti-governmental scientific organizations. One of these, the Fachgemeinschaft der deutschen Höchschulehrer der Physik (Professional Association of the German Higher Education Teachers of Physics), he established as an attempt to counterbalance the older, more liberal Deutsche Physikalische Gesellschaft (German Physical Society), based in Berlin.

When Stark decided to return to academic life, he found that he had made too many enemies and offended too many colleagues. He was rejected for posts at the universities of Berlin and Tübingen in 1924, Breslau and Marburg in 1926, Heidelberg in 1927, and Munich in 1928. By the early 1930s, Stark had become almost entirely an administrator of science, and then only in posts that his political influence had won for him. During the mid-1930s, he worked diligently to gain control over the direction of German science policymaking, but eventually lost out in that struggle to men who were even more closely allied to Adolf Hitler and the Nazi party.

By the beginning of World War II, Stark had become a self-made loner, having angered and annoyed both his former scientific colleagues and his former political allies. He sat out the war in his estate of Eppenstatt, in Bavaria, where he had constructed a laboratory. Stark had married Louise Uepter and had five children; beyond his professional interests Stark also enjoyed forestry and cultivating fruit trees. In 1947 he was sentenced to four years in a labor camp by a German de-Nazification court; he died in Eppenstatt on June 21, 1957.