Hans Christian Oersted (1777-1851)

Electromagnetism

Born to a pharmacist in Rudkoebing in central Denmark, Oersted became a professor of physics at the University of Copenhagen in 1806. Like many contemporary investigators, he sought to identify the links that were widely expected to exist between electricity and magnetism. In 1812, his View of Chemical Laws announced his belief in the relationship, based partly on a philosophical conviction, in the inherent interconvertibility of all forces, but also on the observation that if electricity could generate heat and light, it could perhaps do the same for magnetism. With the probable exception of the Italian lawyer Gian Domenico Romagnosi, who only published his results in his local newspaper, no experimenter had hitherto succeeded in getting the new-found power of the voltaic pile to make an electrical current deflect a compass needle.

However, in 1819-20 Oersted discovered the fundamental connection during a classroom experiment: the needle was unexpectedly deflected at right angles to the plane of the current. Moreover, Oersted inferred that the current tended to generate magnetic forces that acted ‘rotationally‘ in a circle around the axis of the wire, a phenomenon that neither he nor fellow physicists could explain at first. Nevertheless, this breakthrough was widely heralded throughout European scientific communities and opened up a whole new field soon known as ‘electromagnetism’. In Denmark Oersted is especially remembered for founding the Danish Society for the Promotion of Natural Science in 1824, and for first isolating metallic aluminium a year later.

In 1932, the international scientific community acknowledged Oersted’s foundational work in electromagnetism by adopting the term "oersted" as the unit of magnetic field intensity.

Web page generated 09 February 2010