German natural philosopher (physicist). Born in Magdeburg in 1602. Died in Hamburg in 1686.
Born into a wealthy aristocratic family in Magdeburg, Germany, Otto von Guericke was well-equipped by fate to pursue whatever fancies occupied his mind. To our fortune, the interest that he eventually pursued was natural philosophy.
Like so many other aristocrats, von Guericke never achieved any sort of degree - his education was eclectic, and he dabbled in lots of subjects. In the 17th century, this was common practice for young aristocrats.
As a young man (from 1617 to 1620), Otto von Guericke studied the humanities at Leipzig. The brewing war in the Leipzig region (this was at the beginning of the Thirty Years' War) caused him to be moved briefly to Helmstedt. However, when his father died the same year, he returned to his home, instead. For about a year, he studied law at Jena, then moved (1622) to Leiden to continue his legal studies there. While at Leiden, he also studied mathematics and military science (fortification, an important subject in those years).
Finishing his studies, he went on a grand tour of Europe (another aristocratic practice), visiting England and France. He returned to Magdeburg in 1626. Upon his return he was, almost at once, elected alderman of the city, and he continued to serve in one capacity or another for the next five decades.
In 1631, the war came to Magdeburg, to the ruin and heartbreak of its citizens. The conflict nearly obliterated the city, and von Guericke, believing he had lost everything, took up employment as a military engineer, building fortifications in the region for the Swedes (at Erfurt), then for the Elector of Saxony (who acquired Magdeburg in 1635). By his careful efforts throughout this period, von Guericke did inestimable service to his city, helping to reconstruct it after its near-ruin.
In 1646, he was elected Burgomeister (mayor, one of four rotating mayoral officials of Magdeburg), and he participated in the diplomatic efforts to resolve the political aftermath of the Thirty Years' War, regularly attending the Imperial Diet at Regensburg in the 1650s, and was ennobled in 1666.
The physical experiments, for which Otto von Guericke is now most known, began as a result of his work as a military engineer. Dissatisfied with the plenist theories of René Descartes, he undertook to disprove Descartes' claim that a vacuum was an impossibility. In 1647, he constructed a suction pump, and worked to develop it further into an air pump (1654). It was at this time that he undertook what is now known as "the experiment of the Magdeburg hemispheres", or simply the Magdeburg experiment.
Using a pump to evacuate the air between two hemispheres of a globe 62 cm in diameter, he demonstrated that it took 16 horses to pull them apart again. The experiment, first reported in Gaspar Schott's Mechanica hydraulico-pneumatica (1657) and repeated in Berlin in 1663 in the presence of Ferdinand III, caught the public imagination. The amazing spectacle of over a dozen horses pulling with all their might, seemingly against nothing at all (though, of course, the opposing force was atmospheric pressure) was impressive, to say the least.
The Magdeburg experiment was more carefully dsescribed by Otto von Guericke himself in Experimenta Nova (ut vocantur) Magdeburgica De Vacuo Spatio, published in Amsterdam, 1672, and dedicated to the Elector of Brandenburg.
Recognising the elasticity of air, he further investigated the subject. When he learned of Evangelista Torricelli's experiments, he undertook to repeat them. He also made an early barometer, and using this to measure changes in atmospheric pressure, made significant steps towards what is now the science of meteorology.
Other subjects studied by von Guericke, although with less enthusiasm and productivity, were astronomy (he was a Copernican, and while he did not carry out many observations, we do know that he observed the comet of 1664) and static electricity (using a large globe of sulphur, with which he could accumulate a static charge).
Today, the University of Magdeburg is named for Otto von Guericke, in recognition of his unusual achievements, both on behalf of his city and in the field of science.*
* I knew this, but it took BtS to remind me. Thanks, dude!