ESHS/HSS Annual Meeting

Hydrodynamic Fields of Force: Bjerknes' Experimental Program on the Mechanical Nature of Electromagnetism

• In Event: Models, Concepts and Boundaries in the 19th and Early 20th Century

English Abstract

In my talk, I want to discuss the epistemic function of physical models and experiments in the study of the mechanical nature of electromagnetism at the end of the 19th century. Carl Anton Bjerknes, professor of mathematics at the Royal Frederik University of Christiania (now Oslo) developed a set of models that showed hydromechanical analogies of electricity and magnetism, specifically the attraction and repulsion of pulsating and vibrating bodies, and the field lines they created in the water. Bjerknes' demonstrations received much acclamation at the 1881 Paris International Electric Exhibition. While Carl Anton had worked in relative isolation, his son Vilhelm Bjerknes worked with Heinrich Hertz in Bonn, which secured him international recognition. Vilhelm continued and extended his father's mathematical and experimental program into the first decade of the 20th century, citing specifically its relation to Hertz's Principles of Mechanics of 1894. Hendrik Anton Lorentz referred to Bjerknes' experiments in his Nobel lecture in 1902 but mechanical theories and models of electromagnetic phenomena quickly lost traction in the physics community. Vilhelm Bjerknes, however, went on to adapt his hydromechanical studies to the atmospheric sciences.
Vilhelm Bjerknes is today celebrated as a founding figure of physical meteorology. While his work in electromagnetism is today rarely mentioned, Bjerknes himself continued to point towards the close connection between the two. What were the attractions and limitations developing physical models exploring the analogies, and why have they disappeared from our historiographies?

Author

• Roland Wittje, University of Oslo, Norway