Hans Christian Oersted

Hans Christian Ørsted—also spelled Oersted—(Rudkøbing, August 14, 1777 – Copenhagen, March 9, 1851) was a Danish physicist and chemist. He is best known for his discovery of the influence of an electric current on the orientation of a compass needle (April 1820). Ørsted, at the time professor of physics at the University of Copenhagen, discovered that a magnetic needle aligns itself perpendicular to a current-carrying wire fed by a Voltaic pile. This was the first evidence that electricity and magnetism are related. Until that time these two natural phenomena were seen as unrelated. The same year Ørsted published his finding in Experimenta circa effectum conflictus electrici in acum magneticam [Experiments on the conflicting effect of electricity on the magnetic needle]. Ørsted did not try to cast his experimental result into a mathematical model, this was done soon after by Biot and Savart, Pierre-Simon Laplace, and most thoroughly by André-Marie Ampère.

Also in 1820 Ørsted discovered piperine, one of the pungent components of pepper. Later (1825) he found how to prepare metallic aluminum. In 1824 Ørsted founded a society devoted to the spread of scientific knowledge among the general public. Since 1908 this society has awarded the Ørsted Medal for outstanding contributions by Danish physical scientists. In 1932 the name oersted was adopted for the physical unit of magnetic field strength in the cgs system of units. Ørsted was one of the founders of the Polytechnical Institute in Copenhagen, now the Technical University of Denmark, where engineering students receive a scientific foundation. He became the first director of this Institute (1829).