Michel Janssen

Professor
Physics and Astronomy
130-27 John T. Tate Hall
+1 612 624 5880
Janssen

Specialities
History of modern physics, relativity and quantum revolutions, Einstein, philosophy of science

Bio
I am a historian of physics studying conceptual developments in the late 19th and early 20th century. I got a Master's in theoretical physics at the University of Amsterdam (1988) and a Ph.D. in History and Philosophy of Science at the University of Pittsburgh (1995). I wrote my dissertation on the history of special relativity, paying special attention to the role of my countryman, H. A. Lorentz. I then worked for several years for the Einstein Papers Project, annotating various documents (published papers, research manuscripts, and correspondence) related to the genesis of general relativity. I continue to publish on the history of both special and general relativity. The main focus of my research, however, has shifted to the history of quantum theory. Together with University of Pittsburgh physicist Tony Duncan, I have published a series of papers on the transition from the old quantum theory to modern quantum mechanics and we are currently working on a book on this topic. A great promotor of such collaborative work in history of science is Jürgen Renn, one of the directors at the Max Planck Institute for the History of Science in Berlin, where I am a regular visitor. Guiding my research in general are broader philosophical questions about theory change. I have been pursuing two ideas in particular. The first is that a new theory sometimes gets off the ground when odd coincidences in the old theory are traced to a common origin (see my paper, "COI Stories").  Second, old theories are often used as scaffolds to build new theories (see my paper, "Arches and Scaffolds").  I have long been interested in making the results of my work accessible to a broad audience. I co-edited The Cambridge Companion to Einstein, an introduction to Einstein's life and work for non-specialists. And I enjoy explaining my work to undergraduates (I have taught several honors seminars at the U and given talks at various liberal arts colleges in the area) and high school students.

Selected Publications

Michel Janssen and Christoph Lehner (eds). The Cambridge Companion to Einstein. Cambridge: Cambridge University Press, 2014

Michel Janssen and Anthony Duncan, "The Stark effect in the Bohr-Sommerfeld theory and in Schrödinger’s wave mechanics." Pp. 217–271 in Finn Aaserud and Helge Kragh (Eds.), One Hundred Years of the Bohr Atom. Copenhagen: Det Kongelige Danske Videnskabernes Selskab, 2015

Michel Janssen and Jürgen Renn, "Arch and scaffold: How Einstein found his field equations." Physics Today, November 2015, pp. 30–36.

Michel Janssen, "COI Stories: Explanation and Evidence in the History of Science." Perspectives on Science 10 (2002): 457-522.

Michel Janssen, "Arches and Scaffolds: Bridging Continuity and Discontinuity in Theory Change." Forthcoming in: Alan C. Love and William C. Wimsatt (Eds.), Beyond the Meme. Articulating Dynamic Structures in Cultural Evolution. Minneapolis: University of Minnesota Press, 2017.