Hans Christian Ørsted (1777 - 1851) was a Danish physicist and chemist who in 1820 discovered that an electric current creates a magnetic field, establishing the connection between electricity and magnetism and founding the science of electromagnetism.[1] His observation that a compass needle is deflected by a nearby current-carrying wire opened one of the most consequential lines of research in nineteenth-century physics.
Early life and education
Ørsted was born on 14 August 1777 in Rudkøbing, a small town on the Danish island of Langeland, where his father worked as a pharmacist.[2] Largely self-taught in his early years, he assisted in the family pharmacy and developed an interest in the natural sciences. He enrolled at the University of Copenhagen, earning a doctorate in 1799 with a dissertation influenced by the philosophy of Immanuel Kant.[1]
Scientific career
After completing his studies, Ørsted travelled through Europe and spent time at the University of Jena, coming into contact with the ideas of German Naturphilosophie. Returning to Denmark, he was appointed professor of physics at the University of Copenhagen in 1806.[1] He became a devoted teacher and public lecturer, and worked to raise the standing of the physical sciences in Danish intellectual life.
Discovery of electromagnetism
In April 1820, during a lecture demonstration, Ørsted noticed that a magnetic compass needle was deflected whenever an electric current flowed through a nearby wire. This showed that electricity and magnetism were physically related, contradicting the prevailing view that the two forces were independent.[1] His short Latin pamphlet announcing the finding circulated rapidly across Europe and prompted immediate further work by physicists such as André-Marie Ampère and Michael Faraday.
Chemistry and later work
Ørsted also made contributions to chemistry. In 1825 he became the first to produce metallic aluminium, isolating the element in impure form.[1] He founded the Society for the Dissemination of Natural Science and, in 1829, established what later became the Technical University of Denmark. His scientific standing was recognised with the Copley Medal of the Royal Society and the Prussian order Pour le Mérite for Sciences and Arts, among numerous other honours.[1]
Legacy
Ørsted died in Copenhagen on 9 March 1851. His name is commemorated in the oersted, the unit of magnetic field strength in the centimetre-gram-second system, and in institutions and awards across Denmark.[3] His 1820 discovery is regarded as a founding moment in the study of electromagnetism.
