History of Magnetism

900 a.C. Magnes, a Hellenic shepherd, walked across a field of black stones (loadstone Fe3O4) and recognized that these stones attracted the iron nails of his sandals.
cannot be dated exactly: Vikings and Chinese used the compass.
1269 Petrus Peregrinus (Italy) found out that loadstone arranges iron needles along lines of longitude between the poles.
1600 William Gilbert, court physician of Queen Elizabeth, discovered the analogy of the geomagnetic field to the stones of Peregrinus. Explanation how the compass works.
1742 Thomas Le Seur and Francis Jacquier discovered that the force between two magnets is proportional to 1/r3.
1750 John Michell discovers that both poles of a magnet have the same strength.
1820 Hans Christian Oersted found out that electric current, flowing through a conductor, aligns compass needles vertical to the conductor.
1820 One week after he had heard of Oersteds discovery, André Marie Ampère showed that conductors flowed through by electric current exert force on each other.
1820 Jean-Baptiste Biot and Felix Savart showed that forces, which are exerted on an magnet by a conductor that is flowed through by electric current, drop with a rate of 1/r (later: Biot-Savart's law).
1825 Ampère published the extensive results of his research on magnetism.
1831 Michael Faraday showed that alternating currents in a circuit also induce currents in a neighboring circuit. Introduction of the "Magnetic flow".
1834 Faraday discovered the self-induction. Emil Lenz defined his law of definition of the direction of induced currents (Lenz's rule).
1838 Faraday ascertained the analogy of induced electricity in isolators and induced magnetism in magnetic materials.
1845 Faraday ceased his four years of rest and discovered that the polarity level of light rotates if it runs in glass along flux lines of an electromagnet (Faraday rotation).
1846 Faraday published the presumption that light is of electromagnetic origin. He discovered diamagnetism, for example in glass, bismuth and other materials.
1847 Weber proposed that diamond magnetism arises from Faraday induction of molecular currents. Diamagnetism is omnipresent and is merely overlapped in para- and ferromagnets.
1850 William Thomson (Lord Kelvin) introduced the magnetic permeability and susceptibility
1864 Maxwell completed his comprehensive characterization of electricity and magnetism (Maxwell Equations).
1879 Edwin Hall discovered the Hall effect.
1896 P. Zeeman discovered the splitting of line spectrum caused by magnetic fields (Zeeman effect).
20th Century Theory of relativity, quantum mechanics, nuclear physics, solid state physics, material sciences ...