(b. Schickenhof. Upper Palatinate, Germany, 15 April 1874; d. Traunstein, Upper Bavaria, Germany. 21 June 1957), experimental physics.
Stark, the son of a farmer, entered the University of Munich in 1894 and received the doctorate in May 1897 for a dissertation entitled “Untersuchungen über Russ” (“Investigations on Lampblack”). After passing the two state examinations required for the teaching of mathematics at an advanced level, he began work on 1 October 1897 at the University of Munich, spending most of his time as private assistant to Eugen Lommel. On I April 1900 he became assistant to Eduard Riecke at the University of Göttingen, where the following autumn he qualified as lecturer and was appointed Privatdozent on 24 October 1900. While noting Stark’s highly developed technical and experimental skill and his gift for conceptualization, the Faculty observed in its confidential report to the university curator that “it is accompanied by a definite deficiency in the area of exact mathematical formulation of the problems under consideration.”.
Stark’s main field of interest was electrical conduction in gases, and his first book dealt with this subject. In 1904 he founded Jahrbuch der Radioaktivität und Elektronik to publish studies in the newly developing field of particle physics. He rapidly acquired a broad understanding of this field through intensive reading of the literature and his own experiments. This knowledge prompted him to test for the existence of the optical phenomenon known as the Doppler effect in canal rays, which had been recognized as fast-moving particles by Wilhelm Wien. The effect had never been detected in terrestrial light sources; but, as Stark later said, he found it “almost effortlessly” in the hydrogen lines. He made this discovery immediately after moving into the new physics institute at Göttingen.
Seeking to determine the scientific significance of his discovery, Stark attempted to make the optical Doppler effect a proof of Einstein’s theory of special relativity and, a year later (1907), with the quantum hypothesis as well. Stark was thus one of the earliest defenders of the hypothesis, and he remained in the forefront of research until 1913. Curiously, after that year he turned vehemently against both the quantum theory and the general theory of relativity. He therefore is still remembered by older physicists as a conservative, indeed as a reactionary.
In his initial campaign for the quantum hypothesis, Stark, following Einstein, sought new natural phenomena that could be understood in terms of it—and only in those terms. Along with many correct deductions, such as the interpretation of the ultraviolet boundary of X radiation due to electron deceleration, he arrived at a considerable number of erroneous interpretations. At the end of 1909 he initiated a vigorous debate with Arnold Sommerfeld on quantum theory that was conducted in the pages of Pkysikalische Zeitschrift and in their correspondence. Stark sought to understand the distinctive features of the radiation—especially the directional dependence —with the aid of the quantum hypothesis of light; and he tried, virtually by brute force, to wrest agreement from Sommerfeld. “I am so bold as to hope.” he wrote, “that just as you changed your position regarding the theory of relativity, so you will modify your stand on the quantum hypothesis and. . . that the differences between us will have been the reason for it.” But it was not difficult for Sommerfeld to point out that Stark had made serious errors in physics. The classical electromagnetic theory was already leading to experimentally discovered directional dependence. Thus Sommerfeld wrote: “Nothing is further from my intention than to begin a feud with you. That would be a very unfair match. For you far surpass me in experimental ideas, just as I excel you in theoretical clarity.” The discussion eventually veered off into a polemic. Only a few months before, Sommerfeld had supported Stark’s appointment to Aachen; the resulting enmity later overshadowed the careers of both men.
On 1 April 1906 Stark had become Dozent in applied physics and photography at the Technical College in Hannover, where he also received the associated post of assistant and was named professor. He soon came into conflict with his superior Julius Precht, who repeatedly requested the Ministry of Education to dismiss Stark and finally succeeded in having him temporarily transferred to Greifswald on 1 October 1907. Following Stark’s return the tensions between the two increased until Stark with the energetic support of Sommerfeld, was appointed full professor at the Technical College in Aachen on 1 April 1909.
With the relatively elaborate equipment available to him in his own laboratory at Aachen, Stark completed his research in progress, chiefly on the dissymmetry of Bremsstrahlung, and undertook new series of experiments on the splitting of spectral lines in an electric field. While at Göttingen he had been encouraged by Woldemar Voigt to investigate this electrical analogy to the magnetic Zeeman effect. Stark’s first preparatory experiment, at the beginning of 1906, had been a failure; but he was successful in October 1913. He described the experiment in a short autobiographical account. Having procured all the necessary equipment—“a high-intensity spectrograph of rather large dispersion, high-tension sources, and Gaede pumps”—he looked for the effect “simultaneously in the hydrogen and helium lines.” An electric field of between 10,000 and 31,000 volts/cm, was established in the canal-ray tube.
One afternoon soon after courses resumed in October, I began recording the canal rays in a mixture of hydrogen and helium. About six o’clock I interrupted the exposure and. . . went to the darkroom to start the developing process. I was naturally very excited, and since the plate was still in the fixing bath, I took it out for a short time to look at the spectrum in the faint yellow light of the darkroom. I observed several lines at the position of the blue hydrogen line, whereas the neighboring helium lines appeared to be simple [“Die Entdeckung des Stark-Effekte”].
At the beginning of July 1913, several months before Stark’s discovery, Niels Bohr published his concept of a quantum-mechanical model of the atom. This provided, in principle, the possibility of understanding the reason for the Stark effect, which the classical theory was powerless to explain. Stark therefore had an opportunity to be doubly gratified, having also been one of the first, after Max Planck and Einstein, to stress the “fundamental significance” of Planck’s elementary law (since 1907). which he had championed in many polemical discussions. Yet, almost incomprehensibly, Stark denied himself the satisfaction of seeing his own experiments confirm a theory for which he had helped prepare the way conceptually, even if he had not directly participated in its creation. Apparently he always had to oppose the accepted point of view. Thus, as Bohr’s theory continued to gain adherents in 1914–1916, Stark set out to reverse this inexorable development. From the moment that Eduard Riecke’s retirement from his chair at Göttingen was announced in June 1914. Stark hoped to be his successor. The process of selection, however, dragged on for years and ended with a bitter dispute between Stark and the Göttingen faculty. In 1917, therefore, Stark went to Greifswald. While there he received the Nobel Prize for physics in 1919, for the “completeness and reliability”of his measurements.
More than ever Stark claimed to be Germany’s leading physicist; and in 1920 he founded, in opposition to the Deutsche Physikalische Gesellschaft, the Fachgemeinschaft der deutschen Hochsehullehrer der Physik. The latter remained an essentially insignificant organization, but with its help Stark managed to join the board of physics (Fachausschuss) of the Notgemeinschaft der Deutschen Wissenschaft and the Helmhottz-Gesellschaft, the two most important science foundations of German scientists. Since the members of the physics boards had to be confirmed by vote of the entire membership, Stark was obliged to resign from the Notgemeinschaft in 1922 and from the Helmholtz-Gesellschaft in 1924.
In 1920 Stark was appointed successor to Wilhelm Wien at Würzburg. He soon quarreled with almost all his colleagues, and tensions reached a peak in a fight over the habilitation of a student. Unhappy with his situation at Würzburg, Stark was able, by virtue of the large sum of money he received with the Nobel Prize, to resign and move to his native Upper Palatinate, where he devoted himself to the development of a porcelain industry. In the difficult postwar years, however, he was unable to make his project a financial success. He decided to return to science but could not obtain another teaching post: he had made too many enemies. The only physicist whom he had not alienated was Philipp Lenard, who had become an outsider and whose battle against “Jewish, dogmatic physics” Stark unreservedly supported.
After the Nazi seizure of power, Stark, as a partisan of Hitler, was appointed president of the Physikalisch-technische Reichsanstalt (PTR), effective 1 April 1933. He conceived ambitious—not to say grandiose—plans for the expansion of the institution, which was to be part of a total reorganization of physics in Germany. Further, in accord with the “Führerprinzip” and in his capacity as resident of the PTR, he hoped to become permanent president of the Deutsche Physikalische Gesellschaft. At the physics congress at Würzburg, however, he encountered such strong resistance, crystallized above all by a courageous speech by Max von Laue, that he had to abandon this ambition. Similarly, Lane again intervened successfully against Stark when he was about to be forced upon the Prussian Academy—with Friedrich Paschen, Max Planck, and Karl Willy Wagner proposing his nomination on the ground that the academy had no real alternative to accepting him.
In June 1934 the government appointed Stark president of the Notgemeinschaft der Deutschen Wissenschaft (which was renamed “Deutsche Forschungsgemeinschaft”), replacing Friedrich Schmidt-Ott. who had been dismissed. In his new, powerful position as head of both this organization and the PTR, Stark intensified his fight against modern theoretical physics, designating its proponents, led by Laue, Arnold Sommerfeld, and Werner Heisenberg, as “white Jews in science”and “viceroys of the Einsteinian spirit”in Germany. Stark emphasized that the Nazi seizure of power and the Nuremberg laws had brought only a partial victory in the fight against the Jews. The “viceroys of Judaism in German intellectual life,” he insisted, must disappear. The violence of his attacks made Stark increasingly appear pathologically quarrelsome.
Struggles within the hierarchy of the Third Reich compelled Stark to retire from the presidency of the Forschungsgemeinschaft at the end of 1936, and he was subsequently pensioned by the PTR. Shortly before the outbreak of war Stark, on bad terms with virtually everyone, retired to his estate of Eppenstatt, near Traunstein in Upper Bavaria. Even more than Philipp Lenard, Stark has been condemned, even despised, by contemporaries and posterity. Nevertheless, he contributed significantly to the development of physics, especially in his earlier years: and he later exerted a strong, if disastrous, influence.
I. Original Works. A complete list of Stark’s writings is in Poggendorff, IV, 1430–1431; V, 1196– 1198; VI, 2524; VIIa. S-Z, I, 485–486.
Papers on the Doppler effect include “Der DopplerEffekt bei den kanalstrahlen Und die Spektra der positiven Atomionen,” in Physikalische Zeitschrift, 6 (1905), 892–897; and “über die Lichtemission der Kanalstrahlen in Wasserstoff,”in Annalen der Physik, 4th ser., 21 (1906), 401–456.
On the quantum hypothesis, see “Elementarquantum der Energie, Modell der negativen und positiven Elektrizität,”in Physikalische Zeitschrift,8 (1907), 881–884; “Beziehung des Doppler–Effekts bei Kanalstrahlen zur Planckschen Strahlungstheorie,” ibid., 913–919;“Zur Energetik und Chemie der Bandenspektra,” ibid., 9 (1908), 85–94, 356–358; “Neue Beobachtungen zu Kanalstrahlen in Beziehnng zur Lichtquantenhypothese,” ibid., 889–900; and “Über Röntgenstrahlen und die atomistische Konstitution der Strahlung,” ibid., 10 (1909), 826.
His major work on the Stark effect is “Beobachtungen über den Effekt des elektrischen Feldes auf Spektrallinien. I-VI ,” in Annalen der Physik, 4th ser., 43 (1914), 965– 1047, and 48 (1915), 193–235, repr. as Johannes Stark. Paul S. Epstein, Der Stark–Effekt, which is vol. 6 of Dokumente der Naturwissenschaft (Stuttgart, 1965).
Among his books are Die Elektrizität in Gasen (Leipzig, 1902); Die Prinzipien der Atomdynamik, 3 vols. (Leipzig, 1910– 1915); Die gegenwärtige Krisis in der deutschen Physik (Leipzig, 1922); Die Axialität der Lichtemission und Atomstruktur (Berlin, 1927); Atomstruktur und Atombindung (Berlin, 1928); Adolf Hitler und die deutsche Forschung (Berlin, 1935): and Jüdische und deutsche Physik(Leipzig, 1941), written with Wilhelm Müller.
Letters from the Stark estate, including 90 percent of his scientific correspondence up to 1920, are at the Staatsbibliothek der Stiftung Preussischer Kulturbesitz, Handschriften Abteilung, Berlin–Dahlem.
II , Secondary Literature. See Armin Hermann, “Die Entdeckung des Stark–Effekte,” in Johannes Stark. Paul S. Epstein, Der Stark-Effekt (Stuttgart, 1965). 7–16; “Albert Einstein und Johannes Stark, Briefwechsel und Verhältnis der beiden Nobelpreisträger,”in Sudfofffs Archiv für Geschichte der Medizin und Naturwissenchaften. 50 (1966), 267–285: “H. A Lorentz — Praeceptor physicae. Sein Briefwechsel mit dem deutschen Nobelpreisträger Johannes Stark,” in Janus, 53 (1966), 99–114; and “Die frühe Diskussion zwischen Stark und Sommerfield über die Quatuenhypothese,” in Centaurus, 12 (1967), 38–59; and Kurt Zierold, Forschungsförderung in drei Epochen. Deutsche Forschungsgemeinschaft. . . (Wiesbaden, 1968), 173 –212.