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 of his discovery professor of physics at the University of Copenhagen, saw that a magnetic needle aligns itself perpendicular to a current-carrying wire fed by a Voltaic pile (the forerunner of the battery). This was the first evidence that electricity and magnetism are related. Until that time these two natural phenomena were seen as separate and unconnected. The same year Ørsted published his finding in the publication Experimenta circa effectum conflictus electrici in acum magneticam [Experiments on the conflicting effect of electricity on the magnetic needle], which he distributed among European physicists. 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.
Around 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 (Selskabet for Naturlærens Udbredelse) devoted to the spread of scientific knowledge among the general public. Since 1909 this society has awarded the H.C. Ørsted Gold Medal for outstanding contributions to Danish physical scientists. Ørsted was the founder of the Polytechnical Institute in Copenhagen, modeled after the École Polytechnique in Paris. This institute is now the Technical University of Denmark, where engineering students receive a scientifically founded education. Ørsted was the first director of this Institute (1829).
In 1932 the name oersted was adopted for the physical unit of magnetic field strength in the cgs system of units.