Hans Christian Ørsted

Discovered electromagnetism, unifying electricity and magnetism into a single phenomenon

Danish physicist Hans Christian Ørsted (1777–1851) altered the course of scientific history during an 1820 lecture when he observed that an electric current deflected a compass needle – the first experimental proof of electromagnetism. This serendipitous discovery, detailed in Experimenta Circa Effectum Conflictus Electrici in Acum Magneticam, revolutionized physics and laid groundwork for modern electrical technologies.

Ørsted's breakthrough demonstrated that electricity and magnetism were interconnected phenomena, inspiring Michael Faraday's subsequent work on electromagnetic induction. The oersted unit of magnetic field strength honors his contribution to field theory.

Beyond physics, Ørsted founded Denmark's Technical University (1829) and advocated for Kantian philosophy in science education. His chemical research produced the first isolation of aluminum (1825) and pioneered metallic element studies.

The annual Ørsted Lecture at American Association of Physics Teachers continues his legacy of scientific communication. His electromagnetic discovery directly enabled technologies from electric motors to telecommunications, making him a pivotal figure in the Second Industrial Revolution.