Professor (2013– ), history of science, University of Minnesota;
Associate professor (2005–2013), history of science, University of Minnesota;
Assistant professor (2000–2005), history of science, University of Minnesota.
Assistant professor, philosophy, Boston University (1997–2000);
Editor, Einstein Papers Project, Boston (1995–2000);
Named an APS Fellow (2012) for his "path-breaking contributions to the history of early twentieth-century physics."
I work on the history of relativity theory (special and general) and quantum theory.
In the history of general relativity, I have been especially interested in Einstein's heroic but ultimately unsuccessful struggle to find a true theory of relativity. My work for the Einstein Papers Project editing all material on general relativity in Vols. 7 and 8 of Einstein's Collected Papers has put me in an ideal position to tell this tale. The moral of my story is that Einstein's struggle was not in vain. Along the way, he achieved important results that are still with us today: a new theory of gravity improving greatly on Newton's and opening up entirely new fields such as relativistic cosmology, gravitational waves, and gravitational lensing. A line from "Love minus zero/no limit," a song by Minnesota's greatest son, Bob Dylan, provided the perfect title for a paper about this story that I wrote for the Cambridge Companion to Einstein of which I am one of the two editors: "'No success like failure …': Einstein's quest for general relativity, 1907-1920."
In the history of special relativity, my main interest is in the transition from the electromagnetic mechanics of Max Abraham to the relativistic continuum mechanics of Max Laue. Work in the history of special relativity typically focuses on the transformations of our concepts of space and time, treating such well-known phenomena as the slowing-down of moving clocks and the universal contraction of moving objects. The profound implications of special relativity for mechanics usually go unaddressed, even though the theory's most famous formula, E = mc2, is part of relativistic mechanics. Classical mechanics lacked the resources to deal with systems involving the interaction of matter and electromagnetic fields, an area of particular interest in the early 1900s. Classical theory led to such baffling and counter-intuitive predictions that electric forces would move a charged body into a position in which its energy is at a maximum rather than at a minimum; or that charged bodies carry momentum that is at right angles with their direction of motion. Many of these puzzles arose from the experiments by Trouton and Noble, analyzed in my dissertation. They are easily solved once classical mechanics is replaced by relativistic mechanics. Even though Einstein identified this transition in 1912 as the watershed advance in relativity theory, it has never been systematically discussed in the extensive literature on the history of special relativity.
In the history of quantum mechanics, I've written several papers with Tony Duncan, a high-energy theorist at the University of Pittsburgh, on the origins of matrix mechanics in dispersion theory and its further development, especially through the work of Pascual Jordan. In 1927, Jordan published his version of the Dirac-Jordan (statistical) transformation theory. It was largely in response to Jordan's work that John von Neumann developed the Hilbert space formalism of quantum mechanics (see our paper "(Never) mind your p's and q's").
Charles Midwinter and Michel Janssen, Kuhn Losses Regained: Van Vleck from Spectra to Susceptibilities, Research and Pedagogy: A History of Early Quantum Physics through its Textbooks. Editors: Massimiliano Badino and Jaume Navarro. Berlin: Edition Open Access, 2013 [abstract]
Anthony Duncan and Michel Janssen, (Never) Mind your p’s and q’s: Von Neumann versus Jordan on the Foundations of Quantum Theory, The European Physical Journal H—Historical Perspectives on Contemporary Physics 38 (2013): 175–259 [abstract]
Michel Janssen, The Twins and the Bucket: How Einstein Made Gravity rather than Motion Relative in General Relativity, Studies in History and Philosophy of Modern Physics 43 (2012): 159–175 [abstract]
Michel Janssen, Drawing the Line between Kinematics and Dynamics in Special Relativity, Studies in History and Philosophy of Modern Physics 40 (2009) 26–52 [abstract]
Michel Janssen and Matthew Mecklenburg, From Classical to Relativistic Mechanics: Electromagnetic Models of the Electron., Interactions: Mathematics, Physics and Philosophy, 1860–1930. Editors: V. F. Hendricks, K. F. Jørgensen, J. Lützen, and S. A. Pedersen. Dordrecht: Springer, 2007
Michel Janssen, Of Pots and Holes: Einstein’s Bumpy Road to General Relativity., Annalen der Physik 14, Supplement (2005)
Anthony Duncan and Michel Janssen, Pascual Jordan’s Resolution of the Conundrum of the Wave-Particle Duality of Light, Studies in History and Philosophy of Modern Physics 39 (2008): 634–666 [abstract]
Anthony Duncan and Michel Janssen, On the Verge of Umdeutung: John Van Vleck and the Correspondence Principle. Part Two, Archive for History of Exact Sciences 61 (2007): 625–671 [abstract]
Anthony Duncan and Michel Janssen, On the Verge of Umdeutung in Minnesota: Van Vleck and the Correspondence Principle. Part One, Archive for History of Exact Sciences 61 (2007): 553–624 [abstract]
Michel Janssen and Jürgen Renn, Untying the Knot: How Einstein Found His Way Back to Field Equations Discarded in the Zurich Notebook, Jürgen Renn (Ed.), Einstein’s Zurich Notebook. Vol. 2, Commentary and Essays. Dordrecht: Springer, 2007.