Otto von Guericke
Encyclopedia
Otto von Guericke (November 20, 1602 – May 11, 1686 (Julian calendar
); November 30, 1602 – May 21, 1686 (Gregorian calendar
)) was a German
scientist, inventor, and politician. His major scientific achievements were the establishment of the physics of vacuum
s and the discovery of electrostatic repulsion.
, Germany
. In 1617 he became a student at the Univerity of Leipzig. Owing to the outbreak of the Thirty Years War his studies at Leipzig were disrupted and subsequently he studied at the Academia Julia in Helmstedt and the universities of Jena and Leyden. At the last of these he attended courses on mathematics, physics and fortification engineering. His education was completed by a nine-month long trip to France and England. On his return to Magdeburg in 1626 he married Margarethe Alemann and became a member of the Ratscollegium of Magdeburg. He was to remain a member of this body until old age. Von Guericke was personally distrustful of the city's enthusiasm for the cause of Gustavus Adolphus but was nonetheless a victim of the fall of Magdeburg to von Tilly's troops in May 1631. Destitute, but fortunate to escape with his life, he was an Imperial prisoner at a camp in Fermersleben until, through the good offices of Ludwig of Anhalt-Cothen, a ransom of three hundred thalers had been paid. Following a period of employment as engineer in the service of Gustavus Adolphus he and his family returned to Magdeburg in February 1632.
For the next decade he was occupied rebuilding his own and the city's fortunes from the ruins of the fire of 1631. Under the Swedish and subsequently Saxon authorities he remained involved in the civic affairs of the city, becoming in 1641 a Kammerer and in 1646 Burgermeister, a position he was to hold for thirty years. His first diplomatic mission on behalf of the city, in September 1642, was to the court of the Elector of Saxony at Dresden to seek some mitigation of the harshness with which the Saxon military commander treated Magdeburg. Diplomatic missions, often dangerous as well as tedious, occupied much of his time for the next twenty years. A private scientific life, of which much remains unclear, was developing in parallel.
His scientific and diplomatic pursuits finally intersected when, at the Reichstag in Regensburg in 1654, he was invited to demonstrate his experiments on the vacuum before the highest dignitaries of the Holy Roman Empire. One of them, the Archbishop Elector Johann Philip von Schonborn, bought von Guericke's apparatus from him and had it sent to his Jesuit-run College at Wurzburg. One of the professors at the College, Fr. Gaspar Schott
, entered into friendly correspondence with von Guericke and thus it was that, at the age of 55, von Guericke's work was first published as an Appendix to a book by Fr. Schott - Mechanica Hydraulico-pneumatica - published in 1657. This book came to the attention of Robert Boyle
who, stimulated by it, embarked on his own experiments on air pressure and the vacuum, and in 1660 published New Experiments Physico-Mechanical touching the Spring of Air and its Effects. The following year this was translated into Latin and, made aware of it in correspondence with Fr. Schott, von Guericke acquired a copy.
In the decade following the first publication of his own work von Guericke, in addition to his diplomatic and administrative commitments, was scientifically very active. He embarked upon his magnum opus - Ottonis de Guericke Experimenta Nova (ut vocantur) Magdeburgica de Vacuo Spatio - which as well as a detailed account of his experiments on the vacuum, contains his pioneering electrostatic experiments in which electrostatic repulsion was demonstrated for the first time and sets out his theologically based view of the nature of Space. In the Preface to the Reader he claims to have finished the book on March 14th 1663 though publication was delayed for another nine years until 1672. In 1664, his work again appeared in print, again through the good offices of Fr. Schott, the first section of whose book Technica Curiosa, entitled Mirabilia Magdeburgica, was dedicated to von Guericke's work. The earliest reference to the celebrated Magdeburg hemispheres
experiment is on p. 39 of the Technica Curiosa where Fr. Schott notes that von Guericke had mentioned them in a letter of July 22nd 1656. Fr. Schott goes on to quote a subsequent letter of von Guericke of August 4th 1657 in which he states that he now had carried out the experiment, at considerable cost, with 12 horses.
The 1660's saw the final collapse of Magdeburg's aim, to which von Guericke had devoted some twwnty years of diplomatic effort, of achieving the status of a Free City within the Holy Roman Empire. On behalf of Magdeburg, he was the first
signatory to the Treaty of Klosterberg (1666) whereby Magdeburg accepted a garrison of Brandenburg troops and the obligation to pay dues to the Great Elector, Friedrich Wilhelm I of Brandenburg. Despite the Elector's crushing of Magdeburg's political aspirations, the personal relationship of von Guericke and Friedrich Wilhelm remained warm. The Great Elector was a patron of scientific scholarship; he had employed von Guericke's son, Hans Otto, as his Resident in Hamburg and in 1666 had named Otto himself to the Brandenburg Rat. When the Experimenta Nova finally appeared it was prefaced with a fulsome dedication to Friedrich Wilhelm. The year 1666 also saw von Guericke's enoblement by Leopold I, Holy Roman Emperor
when he changed the spelling of his name from "Gericke" to "Guericke" and when he became entitled to the prefix "von". Schimank p.69 reproduces von Guericke's petition to Leopold requesting the prefix "von" and the change of spelling.
In 1677 von Guericke, after repeated requests, was reluctantly permitted to step down from his civic responsibilities. In January 1681, as a precaution against an outbreak of plague then affecting Magdeburg, he and his second wife Dorothea moved to the home of his son Hans Otto in Hamburg
. There he died peacefully on May 11th (Julian) 1686, 55 years to the day after he had fled the flames in 1631. His body was returned to Magdeburg for interment in the Ulrichskirche on May 23rd (Julian) (Schneider p. 144). The Otto von Guericke University of Magdeburg
is named after him.
There are only three important contemporary sources describing Von Guericke's scientific work - Fr. Schott's Mechanica Hydraulico-pneumatica and Technica Curiosa of 1657 and 1664 and his own Experimenta Nova of 1672. His scientific concerns may be divided into three areas, to each of which a Book of the Experimenta Nova is dedicated as follows:
. He is explicitly critical of the plenist views of Aristotle
and of their adoption by his younger contemporary Descartes. A particular and repeated target of his criticism is the manner in which the "nature abhors a vacuum" principle had migrated from simply a matter of experiment to a high principle of physics which could be invoked to explain phenomena such as suction but which itself was above question. In setting out his own view, von Guericke, while acknowledging the influence of previous philosophers such as Lessius (but not Gassendi
), makes it clear that he considers his thinking on this topic to be original and new. There is no evidence that von Guericke was aware of the "Nouvelles Experiences touchant le vide" of Blaise Pascal
published in 1647. In the Experimenta Nova Book III Ch. 34 he relates how he first became aware of Torricelli
's mercury tube experiment from Valerianus Magnus
at Regensburg in 1654. Pascal's work built upon reports of the mercury tube experiment which had reached Paris via Marin Mersenne
in 1644. An indication of the unresolved status of the "nature abhors a vacuum" principle at that time may be taken from Pascal's opinion, expressed in the conclusion of the Nouvelles Experiences, when he writes: "I hold for true the maxims set out below : (a) that all bodies possess a repugnance to being separated one from another and from admitting a vacuum in the interval between them - that is to say that nature abhors a void." Pascal goes on to claim that this abhorrence of a void is however a limited force and thus that the creation of a vacuum is possible.
There were three broad currents of opinion from which von Guericke dissented. Firstly there was the Aristotelian view that there simply was no void and that everything that exists objectively is in the category of substance.An Aristotelian could take a position on the spectrum between the view that the non-existence of the void was just a brute fact (like the non-existence of unicorns) or it was a high principle of physics (like conservation of energy). Aristotle's general position remains attractive to people of a positivist turn of mind, inclined to laying about them with Occam's razor. The general plenist position lost credibility in the 17th century, owing primarily to the success of Newtonian mechanics. It was revived again in the 19th century as a theory of an all pervading aether and again lost plausibility with the success of Special Relativity
. Secondly, there was the Augustinian position of an intimate relation between space time and matter; all three, according to St. Augustine
in the Confessions and the City of God, came into being as a unity and ways of speaking that purport to separate them - such as "outside the universe" or "before the beginning of the universe" are, in fact, meaningless. Augustine's way of thinking is also attractive to many and seems to have a strong resonance with General Relativity
. The third view, which von Guericke discusses at length, but does not attribute to any individual, is that Space is a creation of the human Imagination. Thus it is not truly objective in the sense that matter is objective. The later theories of Leibniz and Kant seem inspired by this general outlook, but the denial of the objectivity of Space has not been scientifically fruitful.
Von Guericke side-stepped the vexed question of the meaning of "nothing" by asserting that all objective reality fell into one of two categories - the created and the uncreated. Space and Time were objectively real but were uncreated, whereas matter was created. In this way he created a new fundamental category alongside Aristotle's category of substance, that of the uncreated. His understanding of Space is theological and similar to that expressed by Newton in the Scholium to the Principia. For instance, von Guericke writes (Book II Chapter VII) "For God cannot be contained in any location, nor in any vacuum, nor in any space, for He Himself is, of His nature, location and vacuum."
consisting of a piston and an air gun cylinder with two-way flaps designed to pull air out of whatever vessel it was connected to, and used it to investigate the properties of the vacuum in many experiments. This pump is described in Chapters II and III of Book III of the Experimenta Nova.Guericke demonstrated the force of air pressure with dramatic experiments.
With his experiments Guericke disproved the hypothesis of "horror vacui
", that nature abhors a vacuum, which for centuries was upheld by philosophers and scientists as aprinciple of nature. Guericke showed that substances were not pulled by a vacuum, but were pushed by the pressure of the surrounding fluids.
All of von Guericke's work on the vacuum and air pressure is described in Book III of the Experimenta Nova (1672). As regards the more detailed chronology of his work we have, in addition to the Experimenta Nova's description of his demonstrations at Regensburg in 1654, the two accounts published by Fr.Schott in 1657 and 1663.
In Chapter 27 he alludes to what transpired at Regensburg in 1654. The first experiment he explicitly records as having been demonstrated was the crushing of a non-spherical vessel as the air was withdrawn from it. He did not use a vacuum pump directly on the vessel but allowed the air in it to expand into a previously evacuated receiver.
The second was an experiment in which a number of men proved able to pull an airtight piston only about half way up a cylindrical copper vessel. Von Guericke then attached his evacuated Receiver to the space below the piston and succeeded in drawing the piston back down again against the force of the men pulling it up. In a letter to Fr. Schott of June 1656, reproduced in Mechanica Hydraulico-pneumatica, von Guericke gives a short account of his experiences at Regensburg. Based on this, Schimank [1936] gives a list of ten experiments which he considers likely to have been carried out at Regensburg. In addition to the above two, these included the extraction of air using a vacuum pump, the extinction of a flame in a sealed vessel, the raising of water by suction, a demonstration that air has weight, and a demonstration of how fog and mist can be produced in a sealed vessel. The Mechanica Hydraulico-pneumatica also provides the earliest drawing of von Guericke's vacuum pump. This corresponds to the description in the opening chapters of Book III of the Experimenta Nova of the first version of his pump.
Stimulated by the interest taken in his work von Guericke was scientifically very active in the decade after 1654. In June 1656 we find him writing to Fr. Schott (Mechanica Hydraulico-pneumatica p.444) "Since the time when I produced the exhibition for the said eminent Elector, I have a better and clearer grasp of all these matters and many other topics as well." The celebrated hemispheres experiment was, as noted in the biographical section above, carried out between July 1656 and August 1657. In Chapter IV of Book III he describes a new and much improved design of vacuum pump and attributes its invention to the need for a more easily transportable machine with which he could demonstrate his experiments to Frederick William who had expressed the desire to see them. The new pump is also described on p. 67 of the Technica Curiosa. The demonstration in the Elector's Library at Colln and der Spree took place in November 1663 and was recorded by a tutor to the Elector's sons. (Schneider p. 113.) There are a number of experiments, such as the rather cruel testing of the effect of a vacuum on birds and fish (Experimenta Nova Book III Chapter XVI), which are not described in the Technica Curiosa. Although the Experimenta Nova does contain correspondence from 1665, there is no reason to doubt von Guericke's assertion that the work was essentially finished by March 1663.
Throughout Books II and III he returns again and again to the theme of there being no abhorrence of a vacuum and that all the phenomena explained by this supposed principle are in fact attributable to the pressure of the atmosphere in conjunction with various incorporeal potencies which he held to be acting. Thus the Earth's "conservative potency" (virtus conservativa) provided the explanation for the fact that the Earth retains its atmosphere though travelling through space. In countering the objection of a Dr. Deusing that the weight of the atmosphere would simply crush the bodies of all living things, he shows explict awareness of the key property of a fluid - that it exerts pressure equally across all planes. In Chapter XXX of Book III he writes: "Dr. Deusing ought to have borne in mind that the air does not just press on our heads but flows all around us. Just as it presses from above on the head, it likewise presses on the soles of the feet from below and simultaneously on all parts of the body from all directions."
to weather prediction and thus prepared the way for meteorology
. His later works focused on electricity, but little is preserved of his results. He invented the first electrostatic generator
, the "Elektrisiermaschine", of which a version is illustrated in the engraving by Hubert-François Gravelot
, c. 1750.
Von Guericke thought of the capacity of body to exert an influence beyond its immediate boundaries in terms of "corporeal and incorporeal potencies". Examples of "corporeal potencies" were the giving off of fumes, smells, gases etc. by bodies. An example of an "incorporeal potencies" was the Earth's "conservative potency" whereby it retained its atmosphere and caused the return of objects thrown upwards to the Earth's surface. The Earth also possessed an "expulsive potency" which was deemed to explain why objects that fall bounce back up again. The notion of an "incorporeal potency" is similar to that of "action at a distance" except the former notion remained purely qualitative and there is no inkling of the fundamental "action and reaction" principle.
Von Guericke describes his work on electrostatics in Chapter 15 of Book IV of the Experimenta Nova. In a letter of November 1661 to Fr. Schott, reproduced in the Technica Curiosa, he notes that the then projected Book IV would be concerned with "cosmic potencies" (virtutes mundanae. Accepting the claim of the preface to the Experimenta Nova that the entire work had been essentially completed before March 1663, von Guericke can be fairly credited with inventing a primitive form of frictional electrical machine before 1663. He used a sulphur globe that could be rubbed by hand.
In Chapter 6 of Book IV von Guericke writes: "It seems reasonable to suppose that if the Earth has a fitting and appropriate attractive potency it will also have a potency of repelling things that might be dangerous or disagreeable to it. This is to be seen in the case of the sulphur sphere described below in Chapter 15. When that sphere is stroked or rubbed not only does it attract all light objects, but it sometimes arbitrarily also repels them before attracting them again. Sometimes indeed it doesn't even attract them again." The key Chapter 15 is entitled "On an experiment, in which these potencies, listed above,can be evoked by the rubbing of a sulphur ball." In Section 3 of this chapter he describes how light bodies are repelled from a sulphur sphere which has been rubbed with a dry hand, and are not again attracted until they have touched another body. These remarks of von Guericke record the first observation of the phenomenon of electrostatic repulsion.
Oldenburg's review of the Experimenta Nova (November 1672) in the Proceeding of the Royal Society does not challenge von Guericke's priority but sceptically observes: "How far this globe may be confided in, the Tryals and Consideration of some ingenious person here may perhaps inform us hereafter." In fact, Robert Boyle
repeated von Guericke's experiments for the Royal Society in November 1672 and February 1673. (Schneider p. 127)
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
); November 30, 1602 – May 21, 1686 (Gregorian calendar
Gregorian calendar
The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...
)) was a German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
scientist, inventor, and politician. His major scientific achievements were the establishment of the physics of vacuum
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
s and the discovery of electrostatic repulsion.
Biography
Otto von Guericke was born to a patrician family of MagdeburgMagdeburg
Magdeburg , is the largest city and the capital city of the Bundesland of Saxony-Anhalt, Germany. Magdeburg is situated on the Elbe River and was one of the most important medieval cities of Europe....
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
. In 1617 he became a student at the Univerity of Leipzig. Owing to the outbreak of the Thirty Years War his studies at Leipzig were disrupted and subsequently he studied at the Academia Julia in Helmstedt and the universities of Jena and Leyden. At the last of these he attended courses on mathematics, physics and fortification engineering. His education was completed by a nine-month long trip to France and England. On his return to Magdeburg in 1626 he married Margarethe Alemann and became a member of the Ratscollegium of Magdeburg. He was to remain a member of this body until old age. Von Guericke was personally distrustful of the city's enthusiasm for the cause of Gustavus Adolphus but was nonetheless a victim of the fall of Magdeburg to von Tilly's troops in May 1631. Destitute, but fortunate to escape with his life, he was an Imperial prisoner at a camp in Fermersleben until, through the good offices of Ludwig of Anhalt-Cothen, a ransom of three hundred thalers had been paid. Following a period of employment as engineer in the service of Gustavus Adolphus he and his family returned to Magdeburg in February 1632.
For the next decade he was occupied rebuilding his own and the city's fortunes from the ruins of the fire of 1631. Under the Swedish and subsequently Saxon authorities he remained involved in the civic affairs of the city, becoming in 1641 a Kammerer and in 1646 Burgermeister, a position he was to hold for thirty years. His first diplomatic mission on behalf of the city, in September 1642, was to the court of the Elector of Saxony at Dresden to seek some mitigation of the harshness with which the Saxon military commander treated Magdeburg. Diplomatic missions, often dangerous as well as tedious, occupied much of his time for the next twenty years. A private scientific life, of which much remains unclear, was developing in parallel.
His scientific and diplomatic pursuits finally intersected when, at the Reichstag in Regensburg in 1654, he was invited to demonstrate his experiments on the vacuum before the highest dignitaries of the Holy Roman Empire. One of them, the Archbishop Elector Johann Philip von Schonborn, bought von Guericke's apparatus from him and had it sent to his Jesuit-run College at Wurzburg. One of the professors at the College, Fr. Gaspar Schott
Gaspar Schott
Gaspar Schott was a German Jesuit and scientist, specializing in the fields of physics, mathematics and natural philosophy, and known for his piety.-Biography:...
, entered into friendly correspondence with von Guericke and thus it was that, at the age of 55, von Guericke's work was first published as an Appendix to a book by Fr. Schott - Mechanica Hydraulico-pneumatica - published in 1657. This book came to the attention of Robert Boyle
Robert Boyle
Robert Boyle FRS was a 17th century natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. He has been variously described as English, Irish, or Anglo-Irish, his father having come to Ireland from England during the time of the English plantations of...
who, stimulated by it, embarked on his own experiments on air pressure and the vacuum, and in 1660 published New Experiments Physico-Mechanical touching the Spring of Air and its Effects. The following year this was translated into Latin and, made aware of it in correspondence with Fr. Schott, von Guericke acquired a copy.
In the decade following the first publication of his own work von Guericke, in addition to his diplomatic and administrative commitments, was scientifically very active. He embarked upon his magnum opus - Ottonis de Guericke Experimenta Nova (ut vocantur) Magdeburgica de Vacuo Spatio - which as well as a detailed account of his experiments on the vacuum, contains his pioneering electrostatic experiments in which electrostatic repulsion was demonstrated for the first time and sets out his theologically based view of the nature of Space. In the Preface to the Reader he claims to have finished the book on March 14th 1663 though publication was delayed for another nine years until 1672. In 1664, his work again appeared in print, again through the good offices of Fr. Schott, the first section of whose book Technica Curiosa, entitled Mirabilia Magdeburgica, was dedicated to von Guericke's work. The earliest reference to the celebrated Magdeburg hemispheres
Magdeburg hemispheres
The Magdeburg hemispheres are a pair of large copper hemispheres with mating rims. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses...
experiment is on p. 39 of the Technica Curiosa where Fr. Schott notes that von Guericke had mentioned them in a letter of July 22nd 1656. Fr. Schott goes on to quote a subsequent letter of von Guericke of August 4th 1657 in which he states that he now had carried out the experiment, at considerable cost, with 12 horses.
The 1660's saw the final collapse of Magdeburg's aim, to which von Guericke had devoted some twwnty years of diplomatic effort, of achieving the status of a Free City within the Holy Roman Empire. On behalf of Magdeburg, he was the first
signatory to the Treaty of Klosterberg (1666) whereby Magdeburg accepted a garrison of Brandenburg troops and the obligation to pay dues to the Great Elector, Friedrich Wilhelm I of Brandenburg. Despite the Elector's crushing of Magdeburg's political aspirations, the personal relationship of von Guericke and Friedrich Wilhelm remained warm. The Great Elector was a patron of scientific scholarship; he had employed von Guericke's son, Hans Otto, as his Resident in Hamburg and in 1666 had named Otto himself to the Brandenburg Rat. When the Experimenta Nova finally appeared it was prefaced with a fulsome dedication to Friedrich Wilhelm. The year 1666 also saw von Guericke's enoblement by Leopold I, Holy Roman Emperor
Leopold I, Holy Roman Emperor
| style="float:right;" | Leopold I was a Holy Roman Emperor, King of Hungary and King of Bohemia. A member of the Habsburg family, he was the second son of Emperor Ferdinand III and his first wife, Maria Anna of Spain. His maternal grandparents were Philip III of Spain and Margaret of Austria...
when he changed the spelling of his name from "Gericke" to "Guericke" and when he became entitled to the prefix "von". Schimank p.69 reproduces von Guericke's petition to Leopold requesting the prefix "von" and the change of spelling.
In 1677 von Guericke, after repeated requests, was reluctantly permitted to step down from his civic responsibilities. In January 1681, as a precaution against an outbreak of plague then affecting Magdeburg, he and his second wife Dorothea moved to the home of his son Hans Otto in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...
. There he died peacefully on May 11th (Julian) 1686, 55 years to the day after he had fled the flames in 1631. His body was returned to Magdeburg for interment in the Ulrichskirche on May 23rd (Julian) (Schneider p. 144). The Otto von Guericke University of Magdeburg
Otto von Guericke University of Magdeburg
The Otto-von-Guericke University Magdeburg was founded in 1993 and is one of the youngest universities in Germany. The university in Magdeburg has about 13,000 students in nine faculties. There are 11,700 papers published in international journals from this institute...
is named after him.
There are only three important contemporary sources describing Von Guericke's scientific work - Fr. Schott's Mechanica Hydraulico-pneumatica and Technica Curiosa of 1657 and 1664 and his own Experimenta Nova of 1672. His scientific concerns may be divided into three areas, to each of which a Book of the Experimenta Nova is dedicated as follows:
- Book II: the nature of space and the possibility of the void
- Book III: the experimental work on the production of vacua, the pressure of air and the Earth's atmosphere
- Book IV: the investigation into electrostatic forces.
Nature of Space and the Possibility of the Void
Book II of the Experimenta Nova is an extended philosophical essay in which von Guericke puts forward a view of the nature of Space similar to that later espoused by NewtonNewton
Newton is a contraction of "New Town", the name of many places in English-speaking countries. It may refer to:-People:* Isaac Newton , English mathematician, philosopher and scientist* Newton , lists of notable people with the surname...
. He is explicitly critical of the plenist views of Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
and of their adoption by his younger contemporary Descartes. A particular and repeated target of his criticism is the manner in which the "nature abhors a vacuum" principle had migrated from simply a matter of experiment to a high principle of physics which could be invoked to explain phenomena such as suction but which itself was above question. In setting out his own view, von Guericke, while acknowledging the influence of previous philosophers such as Lessius (but not Gassendi
Gassendi
* Pierre Gassendi was a French philosopher, scientist and mathematician* Gassendi is a large crater on the Moon named after him...
), makes it clear that he considers his thinking on this topic to be original and new. There is no evidence that von Guericke was aware of the "Nouvelles Experiences touchant le vide" of Blaise Pascal
Blaise Pascal
Blaise Pascal , was a French mathematician, physicist, inventor, writer and Catholic philosopher. He was a child prodigy who was educated by his father, a tax collector in Rouen...
published in 1647. In the Experimenta Nova Book III Ch. 34 he relates how he first became aware of Torricelli
Torricelli
-People:* Evangelista Torricelli, an Italian physicist and mathematician* Robert Torricelli, a former United States politician* Moreno Torricelli, a former Italian football player* Giuseppe Antonio Torricelli, an Italian sculptor-Science:* Torricelli's Law...
's mercury tube experiment from Valerianus Magnus
Valerianus Magnus
Valerianus Magnus or Valeriano Magni was an Italian Capuchin, missionary preacher in Central Europe, polemist and author.-Biography:...
at Regensburg in 1654. Pascal's work built upon reports of the mercury tube experiment which had reached Paris via Marin Mersenne
Marin Mersenne
Marin Mersenne, Marin Mersennus or le Père Mersenne was a French theologian, philosopher, mathematician and music theorist, often referred to as the "father of acoustics"...
in 1644. An indication of the unresolved status of the "nature abhors a vacuum" principle at that time may be taken from Pascal's opinion, expressed in the conclusion of the Nouvelles Experiences, when he writes: "I hold for true the maxims set out below : (a) that all bodies possess a repugnance to being separated one from another and from admitting a vacuum in the interval between them - that is to say that nature abhors a void." Pascal goes on to claim that this abhorrence of a void is however a limited force and thus that the creation of a vacuum is possible.
There were three broad currents of opinion from which von Guericke dissented. Firstly there was the Aristotelian view that there simply was no void and that everything that exists objectively is in the category of substance.An Aristotelian could take a position on the spectrum between the view that the non-existence of the void was just a brute fact (like the non-existence of unicorns) or it was a high principle of physics (like conservation of energy). Aristotle's general position remains attractive to people of a positivist turn of mind, inclined to laying about them with Occam's razor. The general plenist position lost credibility in the 17th century, owing primarily to the success of Newtonian mechanics. It was revived again in the 19th century as a theory of an all pervading aether and again lost plausibility with the success of Special Relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
. Secondly, there was the Augustinian position of an intimate relation between space time and matter; all three, according to St. Augustine
St. Augustine
-People:* Augustine of Hippo or Augustine of Hippo , father of the Latin church* Augustine of Canterbury , first Archbishop of Canterbury* Augustine Webster, an English Catholic martyr.-Places:*St. Augustine, Florida, United States...
in the Confessions and the City of God, came into being as a unity and ways of speaking that purport to separate them - such as "outside the universe" or "before the beginning of the universe" are, in fact, meaningless. Augustine's way of thinking is also attractive to many and seems to have a strong resonance with General Relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
. The third view, which von Guericke discusses at length, but does not attribute to any individual, is that Space is a creation of the human Imagination. Thus it is not truly objective in the sense that matter is objective. The later theories of Leibniz and Kant seem inspired by this general outlook, but the denial of the objectivity of Space has not been scientifically fruitful.
Von Guericke side-stepped the vexed question of the meaning of "nothing" by asserting that all objective reality fell into one of two categories - the created and the uncreated. Space and Time were objectively real but were uncreated, whereas matter was created. In this way he created a new fundamental category alongside Aristotle's category of substance, that of the uncreated. His understanding of Space is theological and similar to that expressed by Newton in the Scholium to the Principia. For instance, von Guericke writes (Book II Chapter VII) "For God cannot be contained in any location, nor in any vacuum, nor in any space, for He Himself is, of His nature, location and vacuum."
Air pressure and the vacuum
Probably around 1650 von Guericke invented a vacuum pumpVacuum pump
A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke.- Types :Pumps can be broadly categorized according to three techniques:...
consisting of a piston and an air gun cylinder with two-way flaps designed to pull air out of whatever vessel it was connected to, and used it to investigate the properties of the vacuum in many experiments. This pump is described in Chapters II and III of Book III of the Experimenta Nova.Guericke demonstrated the force of air pressure with dramatic experiments.
With his experiments Guericke disproved the hypothesis of "horror vacui
Horror vacui (physics)
In physics horror vacui, or plenism, is a theory first proposed by Aristotle in the Fourth book of Physics that nature abhors a vacuum, and therefore empty space would always be trying to suck in gas or liquids to avoid being empty. The theory was widely accepted for a long time and supported by...
", that nature abhors a vacuum, which for centuries was upheld by philosophers and scientists as aprinciple of nature. Guericke showed that substances were not pulled by a vacuum, but were pushed by the pressure of the surrounding fluids.
All of von Guericke's work on the vacuum and air pressure is described in Book III of the Experimenta Nova (1672). As regards the more detailed chronology of his work we have, in addition to the Experimenta Nova's description of his demonstrations at Regensburg in 1654, the two accounts published by Fr.Schott in 1657 and 1663.
In Chapter 27 he alludes to what transpired at Regensburg in 1654. The first experiment he explicitly records as having been demonstrated was the crushing of a non-spherical vessel as the air was withdrawn from it. He did not use a vacuum pump directly on the vessel but allowed the air in it to expand into a previously evacuated receiver.
The second was an experiment in which a number of men proved able to pull an airtight piston only about half way up a cylindrical copper vessel. Von Guericke then attached his evacuated Receiver to the space below the piston and succeeded in drawing the piston back down again against the force of the men pulling it up. In a letter to Fr. Schott of June 1656, reproduced in Mechanica Hydraulico-pneumatica, von Guericke gives a short account of his experiences at Regensburg. Based on this, Schimank [1936] gives a list of ten experiments which he considers likely to have been carried out at Regensburg. In addition to the above two, these included the extraction of air using a vacuum pump, the extinction of a flame in a sealed vessel, the raising of water by suction, a demonstration that air has weight, and a demonstration of how fog and mist can be produced in a sealed vessel. The Mechanica Hydraulico-pneumatica also provides the earliest drawing of von Guericke's vacuum pump. This corresponds to the description in the opening chapters of Book III of the Experimenta Nova of the first version of his pump.
Stimulated by the interest taken in his work von Guericke was scientifically very active in the decade after 1654. In June 1656 we find him writing to Fr. Schott (Mechanica Hydraulico-pneumatica p.444) "Since the time when I produced the exhibition for the said eminent Elector, I have a better and clearer grasp of all these matters and many other topics as well." The celebrated hemispheres experiment was, as noted in the biographical section above, carried out between July 1656 and August 1657. In Chapter IV of Book III he describes a new and much improved design of vacuum pump and attributes its invention to the need for a more easily transportable machine with which he could demonstrate his experiments to Frederick William who had expressed the desire to see them. The new pump is also described on p. 67 of the Technica Curiosa. The demonstration in the Elector's Library at Colln and der Spree took place in November 1663 and was recorded by a tutor to the Elector's sons. (Schneider p. 113.) There are a number of experiments, such as the rather cruel testing of the effect of a vacuum on birds and fish (Experimenta Nova Book III Chapter XVI), which are not described in the Technica Curiosa. Although the Experimenta Nova does contain correspondence from 1665, there is no reason to doubt von Guericke's assertion that the work was essentially finished by March 1663.
Throughout Books II and III he returns again and again to the theme of there being no abhorrence of a vacuum and that all the phenomena explained by this supposed principle are in fact attributable to the pressure of the atmosphere in conjunction with various incorporeal potencies which he held to be acting. Thus the Earth's "conservative potency" (virtus conservativa) provided the explanation for the fact that the Earth retains its atmosphere though travelling through space. In countering the objection of a Dr. Deusing that the weight of the atmosphere would simply crush the bodies of all living things, he shows explict awareness of the key property of a fluid - that it exerts pressure equally across all planes. In Chapter XXX of Book III he writes: "Dr. Deusing ought to have borne in mind that the air does not just press on our heads but flows all around us. Just as it presses from above on the head, it likewise presses on the soles of the feet from below and simultaneously on all parts of the body from all directions."
Other research
Guericke applied the barometerBarometer
A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. Pressure tendency can forecast short term changes in the weather...
to weather prediction and thus prepared the way for meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
. His later works focused on electricity, but little is preserved of his results. He invented the first electrostatic generator
Electrostatic generator
An electrostatic generator, or electrostatic machine, is a mechanical device that produces static electricity, or electricity at high voltage and low continuous current...
, the "Elektrisiermaschine", of which a version is illustrated in the engraving by Hubert-François Gravelot
Hubert-François Gravelot
Hubert-François Bourguignon, commonly known as Gravelot , was a French engraver, a famous book illustrator, designer and drawing-master...
, c. 1750.
Electrostatic Investigations
Von Guericke describes his work on electrostatics in Chapter 15 of Book IV of the Experimenta Nova. In a letter of November 1661 to Fr. Schott, reproduced in the Technica Curiosa, he notes that the then projected Book IV would be concerned with "cosmic potencies" (virtutes mundanae. Accepting the claim of the preface to the Experimenta Nova that the entire work had been essentially completed before March 1663, von Guericke can be fairly credited with inventing a primitive form of frictional electrical machine before 1663. He used a sulphur globe that could be rubbed by hand.
In Chapter 6 of Book IV von Guericke writes: "It seems reasonable to suppose that if the Earth has a fitting and appropriate attractive potency it will also have a potency of repelling things that might be dangerous or disagreeable to it. This is to be seen in the case of the sulphur sphere described below in Chapter 15. When that sphere is stroked or rubbed not only does it attract all light objects, but it sometimes arbitrarily also repels them before attracting them again. Sometimes indeed it doesn't even attract them again." The key Chapter 15 is entitled "On an experiment, in which these potencies, listed above,can be evoked by the rubbing of a sulphur ball." In Section 3 of this chapter he describes how light bodies are repelled from a sulphur sphere which has been rubbed with a dry hand, and are not again attracted until they have touched another body. These remarks of von Guericke record the first observation of the phenomenon of electrostatic repulsion.
Oldenburg's review of the Experimenta Nova (November 1672) in the Proceeding of the Royal Society does not challenge von Guericke's priority but sceptically observes: "How far this globe may be confided in, the Tryals and Consideration of some ingenious person here may perhaps inform us hereafter." In fact, Robert Boyle
Robert Boyle
Robert Boyle FRS was a 17th century natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. He has been variously described as English, Irish, or Anglo-Irish, his father having come to Ireland from England during the time of the English plantations of...
repeated von Guericke's experiments for the Royal Society in November 1672 and February 1673. (Schneider p. 127)
Literature
(Except for the first, all these books are in German or Latin)- Thinking about Nothing: Otto von Guericke and the Magdeburg Experiments on the Vacuum
- Conlon, Thomas E. St. Austin Press 2011
- ISBN 978-1-4478-3916-3
- Die Welt im leeren Raum.
- Otto von Guericke 1602-1686., Ausstellungskatalog, 2002.,
- ISBN 3-422-06374-9
- Otto von Guericke.
- Schneider, Ditmar: Ein Leben für die Alte Stadt Magdeburg. 2004,
- ISBN 3-519-25153-1
- Neue 'Magdeburgische' Versuche über den leeren Raum
- Otto von Guericke,
- Reihe Ostwalds Klassiker, Bd. 59: Übersetzung von Guerickes "Experimenta nova Magdeburgica de vacuo spatio", 1672. (Magdeburger Halbkugeln) 1996,
- ISBN 3-8171-3059-7
- Guericke, Otto von: Gesamtausgabe, 24 Bde.
- Bd.2/1/1 Guericke, Otto von: Otto von Guerickes Neue (so genannte) Magdeburger Versuche über den leeren Raum. Ottonis de Guericke Experimenta Nova (ut vocantur) Magdeburgica de Vacuo Spatio. Faksimile d. latein. Ausg., 1672. 2002.
- ISBN 3-89923-015-9,
- Otto von Guericke, Burgermeister der Stadt Magdeburg: Ein Lebensbild aus dem Deutschen Geschichte des Siebzehnten Jahrhunderts
- Hoffman, Friedrich Wilhelm (Verlag von Emil Baensch)(1874)
- ISBN 9 781145 081925
- Otto von Guericke: Burgermeister von Magdeburg. Ein deutscher Staatsman, Denker und Forscher
- Schimank, Hans (Herausgegeben von der Stadt Magdeburg)(1936)
- Otto von Guericke Philosophisches uber den leeren Raum
- Kauffeldt, Alfons (Akademie-Verlag Berlin) (1968)
- Mechanica Hydraulico-pneumatica
- Schott, Gaspar S.J. (Heinricus Pigin of Wurzburg)(1657) (also Googlebooks)
- Technica Curiosa
- Schott, Gaspar S.J. (Jobus Hertz of Wurzburg) (1664) (also Googlebooks)
External links
Otto von Guericke|Otto von Guericke- University at Magdeburg
- The complete text of Experimenta nova (ut vocantur) magdeburgica de vacuo spatio primùm
- http://www.desy.de/expo2000/deutsch/dhtmlbrowser/webthemen/04_vakuum/ottovonguericke_druck.htm
- Short Biography
- http://www.volksstimme.de/guericke/default.asp?column=introduktion
- Extensive pages on the Guericke Year in Magdeburg
- http://www.deutsches-museum.de/en/collections/ausgewaehlte-objekte/meisterwerke-i/halbkugel/
- The famous half-spheres
- http://video.uni-magdeburg.de/film.php?Kennz=8
- Otto of Guericke and Magdeburg hemisphere video (currently not available )
- http://www.mdcc-fun.de/rhythm.university/otto.gericke.video.translation.introduction.html
- English video translation
- http://www.thomaseconlon.info/OttovonGuericke1.html
- Online source material for Otto von Guericke