Otto von Guericke (UK: /ˈɡɛərɪkə/, US: /ˈɡ(w)ɛərɪkə, -ki/; German: [ˈɔtoː fɔn ˈɡeːʁɪkə]; spelled Gericke until 1666; born 30 November [O.S. 20 November] 1602 – died 21 May [O.S. 11 May] 1686) was a German scientist, inventor, mathematician, and physicist. His important scientific work included developing experimental methods and repeatable experiments about the physics of the vacuum, atmospheric pressure, and electrostatic repulsion. He supported the idea of "action at a distance" and the concept of "absolute space." These contributions were important for the Scientific Revolution.
Biography
Otto von Guericke was born into a wealthy family in Magdeburg. He received private lessons until he turned fifteen. In 1617, he began studying law and philosophy at Leipzig University. However, in 1620, his studies were interrupted by his father’s death. He briefly returned home before continuing his education at the Academia Julia in Helmstedt and later at the universities of Jena and Leiden. At Leiden, he first took classes in mathematics, physics, and military engineering. He completed his education with a nine-month trip to France and England.
When he returned to Magdeburg in 1626, he married Margarethe Alemann. They had three children—Anna Catherine, Hans Otto, and Jacob Christopher—before Margarethe died in 1645. Anna Catherine and Jacob Christopher died as infants, and in 1652, Otto married Dorothea Lentke.
Otto was born into one of Magdeburg’s most influential families, which were well-educated and connected. His father and grandfather had both served on the city council and held mayor positions. In 1626, Otto began working as a political representative for Magdeburg and joined the city council. However, the Thirty Years’ War had started in 1618, a long and destructive conflict that soon reached Magdeburg. In 1630, Otto fled the city before an army from the imperial Catholic League, led by Count Tilly, surrounded and attacked Magdeburg. This event, known as the Sack of Magdeburg, was one of the war’s most devastating moments. In May 1631, imperial troops destroyed the city walls, looted its riches, and killed about 80% of its 25,000 residents. Fires destroyed nearly 1,700 of Magdeburg’s 1,900 buildings, including Otto’s personal property. He returned to Magdeburg in 1631, and his engineering background earned him a position on the city’s reconstruction committee.
To rebuild his personal wealth and help Magdeburg, Otto became a master brewer. In 1646, he was elected Burgomeister, the city’s chief magistrate, a role that held significant power. He held this position until his retirement in 1678. During his time in office, he traveled to many European courts and councils, meeting leaders such as kings, dukes, and emperors. In 1666, Emperor Leopold I granted Otto the title of nobility, allowing him to use the name "von Guericke" and change his last name’s spelling from "Gericke" to "Guericke."
Otto’s first diplomatic mission in 1642 took him to Dresden, where he sought better treatment for Magdeburg from the Saxon military commander. In 1648, he represented Magdeburg at the peace treaty that ended the Thirty Years’ War. During a 1654 mission to Regensburg, Otto demonstrated his invention of an air pump to impress officials and support his goals. His diplomatic work, which was often dangerous and demanding, occupied much of his time for two decades. Otto used his official position and scientific knowledge to advance Magdeburg’s political interests. He showcased inventions like the air pump and electrostatic generator to impress audiences and improve communication. When necessary, he avoided explaining the technical details of his inventions, leaving people to believe in his skill.
Inspired by the idea of space as described by Copernicus, Otto studied how air and matter behave in empty space. He first tested vacuum concepts using fire pumps to remove water from wooden barrels but found that water trapped air entered the barrels, ruining the vacuum. In 1647, he switched to removing air from enclosed spaces to solve this problem.
Otto’s scientific and diplomatic work came together in 1654 when he demonstrated his vacuum experiments at the Reichstag in Ratisbon before the Holy Roman Empire’s leaders. He built a vacuum pump, removed air from two joined Magdeburg hemispheres, and attached horses to each side to pull them apart, proving the power of air pressure. He repeated this demonstration for the King of Prussia in 1663 and received a lifetime pension. One leader, Archbishop Johann Philipp von Schönborn, purchased Otto’s equipment and sent it to a Jesuit college in Würzburg. A professor there, Fr. Gaspar Schott, corresponded with Otto, and in 1657, Otto’s work was published as an appendix to Schott’s book Mechanica Hydraulico-pneumatica. This book influenced Robert Boyle, who later conducted his own experiments on air pressure and the vacuum.
After his work was published, Otto continued his scientific research alongside his diplomatic duties. He wrote Ottonis de Guericke Experimenta Nova Magdeburgica de Vacuo Spatio, which detailed his vacuum experiments and early electrostatic demonstrations. He also shared his views on the nature of space. Though he completed the book in 1663, it was not published until 1672. In 1664, Schott again helped publish parts of Otto’s work in Technica Curiosa, where the famous Magdeburg hemispheres experiment was first described.
The 1660s marked the end of Magdeburg’s hope to gain Free Imperial City status, a goal Otto had worked toward for two decades through diplomacy.
Scientific work
Book II of the Experimenta Nova is a long philosophical essay in which von Guericke shared his ideas about the nature of space. His views were similar to those later expressed by Newton. He criticized the ideas of Aristotle and Descartes, who believed space was always full. He specifically opposed the idea that "nature abhors a vacuum," which had become a rule in physics used to explain things like suction, even though it was not based on experiments. Von Guericke said his ideas were new and not copied from others like Lessius, though he did not mention Gassendi. There is no evidence he knew about Pascal’s work from 1647. In Book III, Chapter 34, he described learning about Torricelli’s mercury tube experiment from Valerianus Magnus in 1654. Pascal’s work built on reports of this experiment shared in Paris by Marin Mersenne in 1644. Pascal wrote that while nature seems to dislike empty space, this is only a limited force, and vacuums can exist.
Von Guericke disagreed with three main ideas. First, Aristotle’s belief that space could not be empty and that everything exists as substance. This view lost support in the 17th century due to Newtonian mechanics but was revived in the 19th century as a theory about an invisible substance called aether, which later failed with Einstein’s theory of relativity. Second, Augustine’s belief that space, time, and matter began together as a single unity, making phrases like "before the universe" meaningless. This idea has similarities with Einstein’s theory of relativity. Third, the belief that space is a human invention, not real in the same way as matter. Later thinkers like Leibniz and Kant shared this view, but it did not lead to scientific progress.
Von Guericke avoided the question of what "nothing" means by dividing reality into two groups: created and uncreated. He believed space and time were real but uncreated, while matter was created. This idea was similar to Newton’s view in the Principia. He wrote that God cannot be contained in space or a vacuum because God is space itself.
In 1650, von Guericke invented a vacuum pump. His design used a piston and cylinder with flaps to remove air from containers. He used it to test how vacuums work. In 1657, he made two large hemispheres, removed all the air, and sealed them. The air pressure outside held them together so tightly that sixteen horses could not pull them apart. It would take over 4,000 pounds of force to separate them. This showed that the idea that nature dislikes vacuums was wrong. Aristotle had argued against vacuums, but von Guericke proved that air pressure, not a vacuum, pushes objects.
All of von Guericke’s experiments on vacuums and air pressure are described in Book III of the Experimenta Nova (1672). Details about his work include accounts from 1654 in Regensburg and later writings by Fr. Schott in 1657 and 1663. In Chapter 27, he described an experiment where a non-spherical container collapsed as air was removed. He also showed that men could not pull a piston up a copper tube unless he used his vacuum pump to create a vacuum below it. A letter from 1656 mentions ten experiments likely done in Regensburg, including using a pump to remove air, extinguishing a flame in a sealed jar, and showing that air has weight. The earliest drawing of his vacuum pump appears in Mechanica Hydraulico-pneumatica, matching his description in Experimenta Nova.
After 1654, von Guericke continued his work. In 1656, he wrote to Fr. Schott that he had improved his understanding of these topics. The famous hemispheres experiment was performed between 1656 and 1657. He designed a better vacuum pump to demonstrate his experiments to Frederick William. A demonstration in 1663 at the Elector’s library was recorded by a tutor. Experiments like those with rats were also conducted.