Otto von Guericke, Physics, Biographies

Related Category: Physics, Biographies

Otto von Guericke[O´tO fun gA´riku] Pronunciation Key, 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.