A German physicist, engineer and natural philosopher who built the first machine to create an electric spark. He used this electrical generator for many experiments with electricity, he was the first man to view electroluminescence.
He invented the first air pump and used it to study the phenomenon of vacuum and the role of air in combustion and respiration. On November 20, 1602, Otto Gericke was born as son of a patrician family resident for three centuries in Magdeburg. The mother, nee Anna von Zweidorff, came from a similar family. It is clear that the family was wealthy. Guericke family inherited extensive property both in the city and in the countryside around it.
Otto Gericke attended the city school to learn read and write, and he was tought additional private lessons. At the age of 15, he entered the Faculty of Arts at the Leipzig University. At the age of 16, with the early stages of the Thirty Years War threateninng Leipzig, his parents moved him to Helmstedt to study jurisprudence at the Helmstedt University. He was there only briefly before the death of his father called him home. When Otto Gericke was 18 years old, his father died and in 1621 he went to Jena to study at the university there. To complete his studies, Otto Gericke studied in Leiden (Netherlands) in 1623. He especially looked into problems of constructing fortresses there and Mathematics, Mechanics and Geometry were the most important subjects. Guericke did not take any degree in all of this–in accordance with his standing and needs. After finishing his studies, he went on a nine months journey through France and England as young men of noble houses were entitled to.
Guericke’s house after the reconstruction of 1637
In 1626, at the age of 24, Otto Gericke returned to Magdeburg and married shortly thereafter. When Guericke returned home after his education, he was elected alderman of Magdeburg almost immediately, and he served the city continuously over the following fifty years. In 1630, he became city contractor. After the destruction of Magdeburg in 1631, as part of the Thirty Years War, he drew up a map of the city for the Swedish authorities. Since he had lost everything for the moment, Guericke became a military engineer in the army of Gustavus II Adolphus of Sweden, though the locale of the work was mostly Magdeburg, and then when control of the city passed into the hands of the Elector of Saxony in 1635, in his service. In this capacity, and also in his capacity as a magistrate of the city, Guericke played a large role in its reconstruction, both its fortifications and its bridges over the Elbe.
He functioned as a diplomatic representative of the city to the occupying powers, and later he represented the city at the peace negotiations that led to the Peace of Westphalia. Guericke attended the Imperial Diet at Regensburg (in the 50′s). Diplomacy consumed much of his time from 1642 until 1666. He was elected one of the four rotating mayors of Magdeburg in 1646 and remained one of the mayors until 1676. On January 4, 1666, Otto Gericke was raised to the peerage by the emperor Leopold I. and was now called Otto von Guericke. Von Guericke was also a brewer in Magdeburg. Although little is said about it, this must have contributed considerably to his income.
In 1663 he built one of his Wettermannchen in Berlin for the Great Elector. His relation to the Great Elector, who became sovreign over Magdeburg as a result of the Peace of Westphalia, is intriguing. Von Guericke’s son was an official in Hamburgin the service of the Great Elector. Apparently the son arranged the construction of the Wettermannchen, and that incident raises the speculation that the clientage of von Guericke, who was a wealthy men, was performed for the benefit of his son.
Guericke’s scientific work
Guericke studied astronomy and as a convinced Copernican, von Guericke was concerned with the nature of space and the possibility of empty space and the means of action across it. He constructed a physical world view, embodying Copernicanism, based on empty space across which magnetic action controls the movements of the planets. Each celestial body has its own finite sphere of activity. In addition to his interest in astronomy as a Copernican, von Guericke owned a telescope, which he apparently did not use extensively. He did observe the comet of 1664 and predicted that comets would return regularly from outer space.
Guericke was conducting several scientific experiments in his yard. He become interested in the atmosphere, thus he studied the work of Galileo and Torricelli. When he learned of the Torricellian experiment, he repeated it, made barometric forecasts of the weather based on systematic observations over a period of years, and proposed a network of stations to make systematic reports of the barometer and weather. He made a special barometer in which the column of mercury moved the arm of a man, which thus pointed out rising and falling pressure. This was the Wettermannchen.
Guericke’s pumps and famous experiments with them
He made his first suction pump in 1647 and continued in the following years to work at improving it into a real air pump. In 1650 he invented the air pump, which he used to create a partial vacuum. Guericke used his pumps to study vacuums and the role of air in combustion and respiration. His first pumps were inverted pumps (for fire fighting) that could evacuate larger volumes of air than could be done using static methods. His latter pump designs used lever pumping systems.
Guericke’s famous experiment with the Magdeburg hemispheres
Otto van Guericke made several very spectacular experiments with his air pumps. In 1654, in a famous series of experiments that were performed before Emperor Ferdinand III at Regensburg, Guericke placed two copper bowls (Magdeburg hemispheres) together to form a hollow sphere about 35.5 cm (14 inches) in diameter. After he had removed the air from the sphere, two teams of eight horses were unable to pull the bowls apart, even though they were held together only by the air around them.
Thus the tremendous force that air pressure exerts was first demonstrated. He demonstrated his experiments in 1657 at the emperor’s court in Vienna. In 1661 he also travelled to Berlin to demonstrate the experiment with the Magdeburg hemispheres to the German Elector Friedrich Wilhelm. A scaled-down version of the demonstration became standard in courses of natural philosophy.
Otto von Guericke in 1672 made a cylinder with a close fitting piston. This he strongly fixed in the vertical position. By a rope and pulley 20 men effortlessly raised the piston to the top of the cylinder. Von Guericke had earlier prepared a large hollow sphere from which he had removed the air using a vacuum pump of his invention. When the sphere was connected to the cylinder atmospheric pressure pushed the piston down in spite of the efforts of the 20 men to restrain it. This demonstrated that the atmosphere was a potential source of energy but a vacuum was also needed to make use of it. No easy means existed of creating a vacuum except by a mechanical pump.
In 1663, Otto von Guericke finished his work “Experimenta nova Magdeburgia de vacuo spatio” (“New Magdeburg Experiments About the Vacuum”), published in Amsterdam 1672. Von Guericke dedicated his Experimenta nova to the Elector of Brandenburg. He received no money for the book because he was known to be wealthy. Guericke used his air pumps for many other experiments including experiments with electricity and magnetism. He proved that a lodestone, or magnet, can attract iron even in a vacuum; and that electrical attraction works in a vacuum as well. Air is needed by neither magnets nor electrics. It is especially significant that air is not needed for electrical attraction.
Guericke’s electric generators
He experimented with what we know to have been static electricity. In 1663 Otto van Guericke invented the first electric generator, which produced static electricity by applying friction in the machine. The generator was made of a large sulphur ball cast inside a glass globe, mounted on a shaft.
The ball was rotated by means of a crank and a static electric spark was produced when a pad was rubbed agains the ball as it rotated. The globe could be removed and used as source for experiments with electricity. It is necessary here to note that von Guericke did not recognize the effect he generated as static electricity.
The first Guericke’s electric generator with a rotating sulphur ball
Later editions increased the speed of the rotation with a belt and and rotating wheel. Electrical demonstrations became a favorite parlor trick for guests, but the electric machine also allowed serios scientists to perform experiments that could not be performed earlier. In 1672 he discovered that the electricity thus produced could cause the surface of the sulfur ball to glow; hence he became the first man to view electroluminescence. It was Guericke who noted that like charges repelled each other.
Through his diplomatic activity, which involved much travel, von Guericke came into contact with intellectual and scientific circles in Germany. He corresponded with Schott, Lubieniechy, Leibniz, et al.
In 1678, after younger aldermen more and more denied his priviledges, he retired. In 1681, Otto von Guericke left Magdeburg and moved to his son in Hamburg. On May 11, 1686, the diplomat and scientist died at the age of 83 in his son’s house. Guericke’s son arranged for the return of the dead to Magdeburg.
Otto van Guericke’s contributions to the social life of Magdeburg and his scientific achievements are well remembered in Germany and his monument on a Magdeburg square is memorizing his life in the city.