Reproduction from Robert Wood, <i>Physical Optics</i>, 1911 showing the optical dispersion by sodium vapour.
Old Quantum Theory
History and Foundations of Quantum Physics: Old Quantum Theory
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The old quantum theory was a period of transition between classical and quantum mechanics. Successive crises led to a gradual disintegration of the mechanical worldview. At first, attempts were made to capture quantum phenomena by ad hoc modifications of the description in classical mechanics, such as quantum conditions. The problems of these attempts led to an increasing awareness that a more fundamental revision of mechanical concepts was necessary.
Research on the life and work of Max Planck as a pioneer of quantum physics concentrates on his institutional, social and personal environment (Dieter Hoffmann). It includes a comprehensive scientific biography of Planck and a new edition of his writings on thermodynamics. Further, a study of his role as an editor of the Annalen der Physik, the transcription of the correspondence between Planck and his co-editor at the Annalen, Wilhelm Wien, as well as an extensive annotated collection of Planck’s Annalen papers, were published in 2008.
Another founding father of quantum theory was Albert Einstein whose papers on quantum physics are the subject of a study based on correspondence and manuscripts available at the Einstein Papers Project (Tilman Sauer). A Cambridge Companion to Einstein, which studies all facets of Einstein’s work and its impact on philosophy, is in preparation (Michel Janssen, Christoph Lehner).
A previous study of the project had pointed out the central role of optical dispersion in the genesis of matrix mechanics (Anthony Duncan, Michel Janssen). For a better understanding of the historical context, a long-term study is conducted on the history of theories and experiments of optical dispersion from 1870 to 1925, and especially on the challenge of reconciling the classical theories of dispersion with quantum theory (Marta Jordi).
A study of the interactions between statistical mechanics and old quantum theory from 1911 to 1925 (Massimiliano Badino) focuses on the way in which the quantum hypothesis changed the understanding and the application of the conceptual tools of statistical mechanics to the description of matter. Related is a study on Erwin Schrödinger's 1912 work on solid dielectrics, which reflects early signatures of Erwin Schrödinger's approach to physical theory and displays the wide range of possible conceptions about the structure of solids before it became accessible experimentally through X-ray diffraction (Christian Joas, Shaul Katzir). An interesting case of transfer of knowledge from pure science to technology is the history of piezoelectricity, leading to such applications as the sonar and frequency control in electronic circuits (Shaul Katzir). Research on the history of radioactivity and early nuclear physics is devoted to the investigation of the relationships between persons and institutions in Germany, and their international connections; it also treats the correlations between experiment and theory in this area (Horst Kant). The investigation concentrates on the research groups at the Kaiser Wilhelm-Institutes of Chemistry and Physics (Berlin) and Medical Research (Heidelberg).
Early atomic physics and the reception of quantum physics in Britain in the 1920s is the subject of a study on J. J. Thomson and G. P. Thomson (James Navarro). The impact that drawings and three-dimensional models of the atom (originally conceived to make atoms and their structure accessible to a broad public) had on the development of atomic physics and its methods is the subject of a study on the emergence of modern physics in the public sphere (Arne Schirrmacher).