In July of 1820, Hans Christian Ørsted announced that a wire carrying electricity from a voltaic pile could deflect a magnetic compass needle, a finding that is now considered the discovery of electromagnetism. Importantly, the technological requirements for Ørsted’s discovery were met no later than 1802, and the discovery would have been straightforward for any natural philosopher who suspected that an electric current could produce magnetism. Yet, despite persistent speculation that electricity and magnetism had a deeper connection, electromagnetism was not discovered until eighteen years later. This case study analyzes why the discovery did not occur sooner and why it was Ørsted who uncovered it. 

 

Ørsted’s discovery was made possible by his metaphysics of nature—acquired from his reading of Immanuel Kant and Friedrich Wilhelm Joseph von Schelling—and his use of that metaphysical picture to develop a theory of electrical conduction which later suggested to him that the current-carrying wire might produce a detectable magnetic effect. Those without Ørsted’s philosophical inclination overlooked the discovery for several reasons. The mathematical approach that was ascendant in Paris between 1805 and 1815 suffered from an early fixation on mathematical formalization and precise measurement and focused only on the pile’s static electric properties overlooking the distinct and important properties of the electric current. The experimentalist approach that was dominant in England and the German states was misled by the association between the pile and the galvanic research tradition into searching the open pile—where no electric current is present—instead of the closed pile for electromagnetism. Additionally, a decline in exploratory experimentation that occurred between the middle of the eighteenth century and the beginning of the nineteenth century prevented experimentalists from discovering electromagnetism in the absence of a correct hypothesis about where to look.