Otto von Guericke (20.11.1602-02.05.1686) was a German physicist. He was born in Magdeburg. In 1617 — 23 he studied at the universities of Leipzig, Helmstedt, Jena and Leiden. In 1646 —78 he was burgomaster of Magdeburg.
In 1641 he invented the air pump and, having improved it, carried out a number of experiments: in 1654 he demonstrated the existence of air pressure (the experiment with the Magdeburg hemispheres), proved its elasticity, determined its density and found that air is a conductor of sound, that sound does not propagate in a vacuum, and so on. About 1660 Guericke built one of the first electrostatic machines. It was a sphere that could rotate about an iron rod as an axis. By turning the sphere and rubbing it with his palms, Guericke electrified it. With the help of this device he studied electrical phenomena, and in particular he discovered the phenomenon of electrical repulsion, electrification by influence and electrical luminescence (in the dark he observed the glow of an electrified sulfur sphere). He also built the first water barometer (1657) and used it to forecast the weather, invented a hygrometer, and built an air thermometer and a manometer (not later than 1662).
He studied magnetic phenomena and noticed the magnetisation of long iron objects placed in the meridional direction during forging. He drew attention to the decrease in the intensity of light on reflection. He was the author of the treatise “New, so-called Magdeburg Experiments on Empty Space” (1672).