5,000 years ago, humans discovered natural magnets (Fe3O4)
2300 years ago, Chinese people polished a natural magnet into a scoop on a smooth surface. Under the effect of geomagnetism, the spoon handle was the first guide in the world.
The Chinese people used magnets and iron needles to rub magnetized 1,000 years ago to make the earliest compass in the world.
Around 1100, China integrated magnet needles and azimuth disks into a magnet-guided instrument for navigation.
1405-1432 Zheng He started a great pioneering move in the history of mankind with a guide meter.
1488-1521 Columbus, Gamma, and Magellan used compasses to conduct world-renowned navigational discoveries.
1600 British William Gibber published his monograph "magnet" about magnetism. He developed the ancient Greeks Thales, Aristotle and other predecessors of the world to learn about magnetism and experiments.
1785 French physicist C. Coulomb established the "Coulomb's law" describing the interaction between charge and magnetic poles.
1820 Danish physicist H.C. Oster discovered current-induced magnetic force.
1831 British physicist M. Faraday discovers electromagnetic induction.
1873 British physicist J.C. Maxwell completed a unified electromagnetic theory in his monograph "On Electricity and Magnetism."
1898-1899 French physicist P. Curie discovered that the ferromagnetic substance became paramagnetism at a specific temperature (Curie temperature).
1905 French physicist P.I. Lang Zhiwan explains the paramagnetic variation with temperature based on statistical mechanics theory.
1907 French physicist P.E. Weiss proposed molecular field theory and extended Lang Zhiwan's theory.
1921 The Austrian physicist W. Pauli proposed that Bohr magnetons serve as basic units of atomic magnetic moments. The American physicist A. Compton proposed that electrons also have spin-dependent magnetic moments.
1928 British physicist P.A.M. Dirac perfectly explained the intrinsic spin and magnetic moments of electrons using relativistic quantum mechanics. And with the German physicist W. Heisenberg to prove the existence of the exchange of electrostatic origin, laid the foundation for the modern magnetics.