Guericke, Otto von
Guericke, Otto von
(ô`tō fən gā`rĭkə), 1602–86, German physicist, noted for his study of pneumatics. He carried out his most important researches while burgomaster (1646–81) of Magdeburg. In the course of his attempts to create a vacuum he made the first air pump (c.1650). To demonstrate the pressure of air he devised the so-called Magdeburg hemispheres—two hollow copper hemispheres fitted together to form a globe c.14 in. (36 cm) in diameter from which the air could be pumped. A famous woodcut depicts the claim that it required two opposing eight-horse teams to pull the hemispheres apart. He invented (1660) a machine to generate electricity from the friction of the hand held against a rotating sulfur ball; he also predicted the periodicity of comets.Guericke, Otto Von
Born Nov. 20, 1602, in Magdeburg; died May 11, 1686, in Hamburg. German physicist. Mayor of Magdeburg from 1646.
In trying to prove the existence of the vacuum, Guericke invented the air pump in 1650. In a series of experiments he proved the existence of air pressure (the experiment with the “Magdeburg hemispheres”), determined the elasticity of air, its ponderability, its ability to support combustion and to conduct sound, and the presence in it of water vapor. Guericke created one of the first electrical machines, a rotating sulfur sphere polished by hand, and discovered the phenomenon of electrical repulsion as well as electrical luminescence. In 1660 he was the first to build a water barometer and use it to predict the weather.
WORKS
Experimenta nova (ut vocantur) Magdeburgica de vacuo spatio. Amsterdam, 1672.REFERENCES
Lebedev, V. I. Istoricheskie opyty po fizike. Moscow-Leningrad, 1937. (Contains translations of excerpts from Guericke’s works.)Hoppe, E. Otto von Guericke. Berlin, 1927.