Physicist and chemist — Hans Christian Ørsted (Rudkøbing, 1777 – Copenhagen, 1851) was a Danish physicist and chemist, professor at the University of Copenhagen. In 1820, during a demonstration lecture, he observed that a compass needle placed near a current-carrying wire was deflected: this was the first experimental proof that electricity produces magnetic effects. This discovery founded electromagnetism and immediately spurred the work of Ampère, Faraday and eventually Maxwell. Ørsted was also the first to isolate metallic aluminium, in 1825. In his honour, the CGS unit of magnetic field strength is called the oersted.

Theories and contributions

  • Ørsted’s experiment — A current-carrying wire deflects the surrounding compass needle, demonstrating that electric currents generate magnetic fields.
  • Birth of electromagnetism — First unification of electrical and magnetic phenomena, the starting point for the work of Ampère, Faraday and Maxwell.

Linked atoms

2 linked atoms.

15 Circuiti elettrici

17 Il campo magnetico