Gilbert discovered that the earth behaves like a giant magnet. Modern scientists have learned even more. The Magnetic Field. The law of Biot and Savart, the force between electric currents, and Ampere's law. Vector Fields and Hydrodynamics.
Force fields have definite properties of their own suitable for scientific study.
The discovery of electromagnetic induction in 1831 creates an important technological breakthrough in the generation of electric power. Electromagnetic induction makes it easy to generate alternating current while transformers make it practical to distribute it over long distances. Maxwell discovers that displacement current produces electromagnetic waves or light. Many properties of light are properties of waves, including reflection, refraction, and diffraction. The Michelson- Morley Experiment.