Background
Carl Viktor Eduard Riecke was born on December 1, 1845, in Stuttgart, Germany.
University of Tübingen, Tübingen, Baden-Württemberg, Germany
In 1866 Riecke entered the University of Tübingen to study mathematics under Carl Neumann, son of Franz Neumann, the great theoretician. He completed his undergraduate studies in 1869.
University of Göttingen, Göttingen, Lower Saxony, Germany
Riecke received his doctorate in 1871 from the University of Göttingen under Wilhelm Weber and Friedrich Kohlrausch and qualified as a professor shortly thereafter.
Carl Viktor Eduard Riecke was born on December 1, 1845, in Stuttgart, Germany.
Riecke received his early education in Stuttgart and in 1866 entered the University of Tübingen to study mathematics under Carl Neumann, son of Franz Neumann, the great theoretician. He also studied experimental physics with E. Reusch, who whetted his interest in theoretical studies in crystal physics. This combination of experimental and theoretical work was to be a hallmark of Riecke’s later work. He completed his undergraduate studies in 1869.
At the beginning of 1870 Riecke was offered a state scholarship to continue his studies at the University of Göttingen. He had hardly begun this work when he was conscripted to serve in the Franco-Prussian War. The following year he returned to Göttingen to study mathematics with Clebsch and experimental physics with W. Weber and Kohlrausch. In May 1871, under Weber’s guidance, he completed his dissertation on the magnetization numbers of iron in weak magnetic fields.
After completing his undergraduate studies in 1869, Riecke took a teaching post in mathematics at a school in Stuttgart. Riecke received his doctorate in 1871 from the University of Göttingen under Wilhelm Weber and Friedrich Kohlrausch and qualified as a professor shortly thereafter.
In 1873 Riecke was called to Göttingen as an extraordinary professor of physics; and in 1881 he became an ordinary professor, taking over Weber’s laboratory and institute. When W. Voigt was named ordinary professor of theoretical physics (1883) at Göttingen, he and Riecke were promised a new physics institute. Although this institute did not actually begin functioning until 1905, Riecke carried out, under difficult conditions, both experimental and theoretical studies over a wide range of areas in physics and physical chemistry during his forty-five-year tenure at Göttingen. His competence in physics is reflected in his textbook. Lehrbuch der Physik (1896), which went through five editions. In 1899 Riecke became the first editor of the journal Physikalische Zeitschrift; he continued his close association with the journal until his death, Even at the age of seventy he remained an active worker in physics. His last work, published posthumously in June 1915, was a rigorous mathematical résumé of particle physics and line spectra in which he concentrated on Bohr’s theory of series spectra in hydrogen and helium.
Early in his career Riecke studied ferromagnetism and showed (1871) that in the presence of weak magnetic fields the magnetization numbers for iron are not independent of the strength of the external field, as had been assumed by Franz Neumann. About 1885 Riecke conducted theoretical and experimental researches in hydrodynamics and later, about 1890, undertook theoretical studies in thermodynamics, concentrating on the concept of thermodynamic potentials, which he applied to problems in physical chemistry. Noteworthy among these studies was one, in 1893 in which he analyzed muscle contraction in living organisms by using thermodynamic potentials.
The chief thrust of Riecke’s research was related to the revival and establishment of granular theories of electricity and crystal structure. The particulate nature of electricity had been proposed by Weber but had been under severe attack during the 1860s and 1870s. It was largely through the efforts of Helmholtz that the granular theory of electricity was revived in the 1880s.
Riecke sought to confirm this atomic hypothesis of electricity: with the aid of (1) Geissler tubes, (2) studies of atmospheric electricity and the motion of electrified particles in the electromagnetic field, (3) mathematical and experimental studies on the behavior of crystals, and (4) researches in the metallic state and electrical conduction in metals. His researches in these areas were not done serially but were intertwined, stretching over the period 1880–1915.
The most noteworthy of his results in Geissler tubes was the identification of negatively charged particles projected from the cathode; and he demonstrated that this charge is the same regardless of the metal from which the cathode is constructed (1899), Riecke’s analysis of the motion of electrified particles in electromagnetic fields (1902) had direct application to the theory of the aurora. Also, he made important contributions to the molecular theory of pyroelectric and piezoelectric phenomena in tourmaline and quartz (1891, 1914). But his most important and influential researches were undoubtedly on the theory of conduction in metals and a granular theory of the properties of metals. Riecke’s major paper on this subject was published in 1898.
He envisaged the metal as being composed of neutral atoms bound together in a lattice. Provision was made for ionization of some of these atoms to explain positive metal ions and negative electrons. The properties of the metal were accounted for by hypothesizing relationships between the two types of charged particles and their environment. The theory attempted to analyze electrical conduction; heat conduction; the Wiedemann-Franz ratio; various contact effects (including the Peltier effect, contact potentials, and the Thompson effect); various phenomena associated with the presence of an external magnetic field (including the Hall effect, the Nernst effect, and the Ledue effect); and electrical and thermal conductivity in alloys.
Riecke’s basic assumption was that the space between molecules contained not only negative but also positive particles. Each metal molecule was capable of discharging both positive and negative charges by collision. The discharged ions then drifted in straight lines until they came under the influence of metal molecules still bound in the lattice, under the influence of which the ions were bent into circular paths of various sizes. Thus the charges would move randomly through the metal. The model was that of gas; and Riecke assumed that the average speed of the particles was proportional to the square root of the absolute temperature, thus making it possible to apply the mathematical techniques of the kinetic theory of gases to the properties of metals.
The Bavarian Academy of Sciences appointed Riecke in 1909 as a corresponding member.