The Dawn of Electro-Magnetism

Abstract

So far, we have explored magnetism and electricity as separate phenomena. This is the legacy of William Gilbert, who recognized that while magnets and electrically charged bodies can exert forces, they do not exert forces on each other: electrically charged bodies attract or repel other electrically charged bodies; magnetic bodies attract or repel other magnetic bodies. This simple and pleasant demarcation was upset by the work of Hans Christian Oersted (1777–1851), who was born in Rudkøbing, Denmark.

Today, Oersted is best known for his discovery of the connection between electrical currents and magnetism. This work, described in the reading selection in this chapter, inspired later experiments on electromagnetic phenomena by both Faraday and Ampère and culminated in Maxwell’s electromagnetic theory of light. Originally written in Latin, Oersted’s Experiments on the Effect of a Current of Electricity on the Magnetic Needle was translated into English and published in 1820 in Thomson’s Annals of Philosophy.

It is sufficiently evident from the preceding facts that the electric conflict is not confined to the conductor, but dispersed pretty widely in the circumjacent space.

—Hans Christian Oersted