Lyne Starling Trimble Public Event Series
Hertha Sponer and the Path from Electron Diffraction to Wave/Particle Duality
Elise Crull, Associate Professor of Philosophy, City College of New York
Friday, March 20, 2026
5:45pm, Reception
6:30pm, Lecture and Q&A
American Center for Physics
555 12th Street NW, Suite 250
Washington, DC 20004
Abstract
Elise Crull.
The historical trajectory from electron diffraction experiments to the acceptance of matter’s wave-particle duality is interesting to trace for several reasons. First, it foregrounds the crucial role in scientific progress of idea exchange among experimentalists—n.b. not experiments—and theorists. This is an aspect of quantum history often minimized to make room for heroic tales of Knabenphysik, that is, the daring theoretical leaps made by Knaben, or “boys.” Second, highlighting experimentalists creates room for the overlooked contributions of women who, if allowed to practice science at all in this period, were usually relegated to labs or classrooms. Hertha Sponer and her significant yet unappreciated role in matter diffraction experiments is a case in point. Third, this complex historical episode offers novel insights regarding how, when, and why a scientific community accepts experimental results as sufficient evidence for new features of reality
Speaker biography
In addition to history and philosophy of science, Elise Crull frequently ponders (sometimes aloud in front of audiences) philosophical problems associated with quantum theory: the quantum-to-classical transition, quantizing gravity, understanding quantum causal models, the metaphysical nature of entanglement (including temporal entanglement!), and, as of late, interpreting the alternate quantum formalisms used in quantum computing. She also has the occasional thought about quantum cosmology. While these questions keep her in conversation with physicists, Crull also loves a good metaphysics chin-wag. Topics of special interest there include ontology, meta-ontology, and mereology. Since her research interests are fundamentally interdisciplinary, she often finds herself engaging with related “meta” issues, such as the ethics of emergent techno-science, science in the public sphere/in education, and the nature of the science-theology-philosophy triad.
In 2024, Crull published The Einstein Paradox: The Debate on Nonlocality and Incompleteness in 1935 with Guido Bacciagaluppi. Another book, God and the Problem of Quantum Physics, will appear in Cambridge University Press’s “Elements” series. She wrote the chapter on Hertha Sponer in last year’s volume Women in the History of Quantum Physics: Beyond Knabenphysik and edited the 2017 volume Grete Hermann: Between Physics and Philosophy.
Top image: Hertha Sponer. AIP Emilio Segrè Visual Archives, from the Lisa Lisco collection, gift of Jost Lemmerich.