William Gilbert (24.05.1544-30.11.1603) was an English physicist. He was born in Colchester. He studied at Cambridge and Oxford. He was court physician to Queen Elizabeth. In 1600 he published the work “On the Magnet, Magnetic Bodies, and the Great Magnet the Earth...”, in which he described his research (more than 600 experiments) on magnetic and electric phenomena and constructed the first theories of electricity and magnetism. He established that a magnet always has two poles, a north and a south one, and that by sawing a magnet apart one can never obtain a magnet with only one pole; that like poles repel and unlike poles attract; and that iron objects acquire magnetic properties under the influence of a magnet (magnetic induction); he found the strengthening of natural magnetism by means of an iron armature. Studying the magnetic properties of a magnetised sphere with a magnetic needle, he concluded that they correspond to the magnetic properties of the Earth, that is, that the Earth is a large magnet. On this basis he explained the dip of the magnetic needle.
He is the founder of the science of electricity. Until 1600 the study of electric phenomena had remained practically at the level of the knowledge of Thales of Miletus, who discovered the electric properties of rubbed amber. Thanks to Gilbert the study of electricity was enriched by a number of discoveries, observations and instruments. With his “versorium” (the first electroscope) he showed that the ability to attract light bodies (straws) belongs not only to rubbed amber but also to diamond, sapphire, carborundum, opal, amethyst, rock crystal, glass, shale, sulfur, sealing wax, rock salt and others, which he called “electrics”. He also noticed that a flame destroys the electric properties that bodies acquire by friction. After Gilbert, electric and magnetic phenomena were studied very slowly, and for more than 100 years little that was new was obtained. He regarded heat (1590) as the motion of the particles of a body. He criticised the teaching of Aristotle and helped to spread the ideas of the Copernican heliocentric system in England.