Hans Christian Ørsted (14.08.1777-9.03.1851) was a Danish physicist and, from 1815, permanent secretary of the Royal Danish Society. He was born in Rudkøbing (Langeland Island). He graduated from the University of Copenhagen (1797). From 1806 he was professor at this university, and from 1829 at the same time director of the Copenhagen Polytechnic.
His work concerned electricity, acoustics and molecular physics. In 1820 he detected the action of an electric current on a magnetic needle, which led to the emergence of a new field of physics — electromagnetism. The idea of an interconnection between different phenomena of nature is characteristic of Ørsted's scientific work; in particular, he was one of the first to put forward (1821) the idea that light is an electromagnetic phenomenon. In 1822 — 23, independently of J. Fourier, he rediscovered the thermoelectric effect and constructed the first thermocouple. He studied experimentally the compressibility and elasticity of liquids and gases and invented the piezometer (1822). He carried out research in acoustics, in particular trying to detect the production of electrical phenomena by sound. He investigated deviations from the Boyle — Mariotte law.
He was a brilliant lecturer and popularizer, organised in 1824 the Society for the Dissemination of Natural Science, created the first physical laboratory in Denmark, and contributed to improving the teaching of physics in the country's educational institutions.
He was an honorary member of many academies of sciences, in particular the St Petersburg Academy of Sciences (1830).