
A Schott diagram depiction of German engineer Otto Guericke's famous circa 1649 beer keg vacuum experiment, in which Guericke and another man (or Guericke's two assistants) try to completely evacuate the fluid from a well-caulked beer keg, so to see if a "vacuum" could be made (at the top of the keg), the existence of which that was deemed impossible by Parmenides.

A Schott diagram depiction of German engineer Otto Guericke's famous circa 1649 beer keg vacuum experiment, in which Guericke and another man (or Guericke's two assistants) try to completely evacuate the fluid from a well-caulked beer keg, so to see if a "vacuum" could be made (at the top of the keg), the existence of which that was deemed impossible by Parmenides.

In science, nature abhors a vacuum, aka "axiom of Aristotle" (Galileo, 1638) or horror vacui, is a postulated, originating in Parmenides c.485BC argument that a void or rather a vacuum, in nature, cannot exist, which became assimilated in the writings of Aristotle (320BC) to the conclusion that vacuums might exist in partially, but are abhorrent to nature. [1]

This void abhorrence postulate, and the two-millennia long debate that followed, can be said to be directly responsible for the invention or development of a number of things: atomic theory (c.450BC), barometer (1643), vacuum pump (1650), piston and cylinder (1650), air pump (1657), steam engine (1690), gas laws (1645-1897), and the science of thermodynamics (1865). In a dictionary sense, the term has come to represent an idiom used to express the idea that empty or unfilled spaces are unnatural as they go against the laws of nature and physics. [2]

Early history

See also: Parmenides vs Heraclitus

The nature abhors a vacuum argument was first presented in stated in Greek physicist-philosopher Parmenides (510-450BC) circa 485 BC by essay “On Nature”, in which he stated, via reasoning and argument, that a void or rather a vacuum, in nature, cannot exist. [1]

The first to object was Leucippus (c.500-450BC) who in circa 475BC invented the now-famous atomic theory, which was stimulated into conception to purposely contradict Parmenides, which stated explicitly that everything in the universe is either atoms or voids, or combinations of both.

Greek standard model philosopher Empedocles (495-435BC) denied the existence of empty space—in his own words: “the universe has no space that is empty nor space that is overcrowded.”

Next, Plato (427-348BC) found the idea of a vacuum inconceivable.

In circa 350BC, Aristotle, student of Plato, declaring the famous dictum horror vacui, on the logic that in a "complete vacuum" infinite speed would be possible because motion would encounter no resistance, hence if infinite speed was impossible, so to is a vacuum. Aristotle seems, however, to have had in mind the conception of a partial void as evidenced by the following view of his on quantities of fire:

“For any two portions of fire, small or great, will exhibit the same ratio of solid to void; but the upward movement of the greater is quicker than that of the less, just as the downward movement of a mass of gold or lead, or any other body endowed with weight, is quicker in proportion to its size.”

The Aristotlean universe, being that it was adopted by Christianity (via Aristotle's mentoring of Alexander the Great), is the model that would go on to dominate scientific thinking for the next millennium-and-a-half.

In 50AD, Hero, a Greek engineer of Alexandria, challenge the horror vacui dictum by attempting to create an artificial vacuum. [14] His Pneumatica employed vacuum logic, e.g. he outlined what seems to have been a Leucippus-base atomic theory in which matter consists of particles mixed with distributed vacua.


Left: Basic "siphon" principle, in which water will drain though a tube as long as final end of the tube is lower than the liquid surface in the reservoir. Center: Italian physicist Galileo Galilei’s circa 1630-1646 experiment for testing the “force of the vacuum”. [13] Right: The 1641 siphon experiment, done by Gasparo Berti, created by means of an 11 meter high column of water. Demo in Rome, for an invited audience which included Raffaelo Magiotti, Athanasius Kircher, and Nicolo Zucchi. [11]

Left: Basic "siphon" principle, in which water will drain though a tube as long as final end of the tube is lower than the liquid surface in the reservoir. Center: Italian physicist Galileo Galilei’s circa 1630-1646 experiment for testing the “force of the vacuum”. [13] Right: The 1641 siphon experiment, done by Gasparo Berti, created by means of an 11 meter high column of water. Demo in Rome, for an invited audience which included Raffaelo Magiotti, Athanasius Kircher, and Nicolo Zucchi. [11]

Cartesian view
In the 1630s, French philosopher-physicist Rene Descartes, supposedly, held the view that there could be no void, no vacuum, because empty space could only be conceived in terms of matter, which is an extension. [8]

Suction pump issues

See main: Pump problem

Sometime in the early 17th century, pumpmakers of the Grand Duke of Tuscany attempted to raise water to a height of 12 meters or more, but found that 10 meters (33 feet) was the limit to which it would rise in the suction pump.

Baliani' s 1630 siphon problem
On July 27, 1630, Italian physicist Giovanni Baliani wrote a letter to Galileo Galilei about the explanation of an experiment he had made in which a siphon, led over a hill about twenty-one meters high, failed to work. Galileo responded with an explanation of the phenomena: he proposed that it was the power of a vacuum which held the water up, and at a certain height (in this case, thirty-four feet) the amount of water simply became too much and the force could not hold any more, like a cord that can only withstand so much weight hanging from it.

Galileo's ideas reached Rome in December of 1638 in his Discorsi. Rafael Magiotti and Gasparo Berti were excited by these ideas, and decided to seek a better way to attempt to produce a vacuum than with a siphon. Magiotti devised such an experiment, and sometime between 1639 and 1641, Berti (with Magiotti, Athanasius Kircher and Nicolo Zucchi present) carried it out. [2]

Four accounts of Berti's experiment exist, but a simple model to his experiment consisted of filling a long tube with water that had both ends plugged up, then placing the tube into a basin already full of water. The bottom end of the tube was opened, and the water that had begun inside of it poured out of the bottom hole into the basin. However, only part of the water in the tube flowed out, and the level of the water inside the tube stayed at an exact level, which happened to be thirty-four feet, the exact height Baliani and Galileo had observed that was limited by the siphon. What was most important about this experiment was that the lowering water had had left a space above it in the tube which had had no intermediate contact with air to fill it up. This seemed to suggest the possibility of a vacuum existing in the space above the water. [3]

A modern small-scale version of Italian physicist Evangelista Torricelli's 1643 testing of the nature abhors a vacuum theory, wherein a filled tube of mercury is upended into a dish of mercury, without letting any mercury escape, the result of which is that the column falls by a certain height which varies with the atmospheric pressure of the earth; the top evacuated space is called "Torricelli vacuum"; the device itself has since come to be called a barometer.

Torricelli's 1643 experiment

See main: Torricelli vacuum

Italian physicist Evangelista Torricelli, a friend and student of Galileo, dared to look at the entire problem from a different angle. In a letter to Michelangelo Ricci in 1644 concerning the experiments with the water barometer, he wrote: [4]

"Many have said that a vacuum does not exist, others that it does exist in spite of the repugnance of nature and with difficulty; I know of no one who has said that it exists without difficulty and without a resistance from nature. I argued thus: If there can be found a manifest cause from which the resistance can be derived which is felt if we try to make a vacuum, it seems to me foolish to try to attribute to vacuum those operations which follow evidently from some other cause; and so by making some very easy calculations, I found that the cause assigned by me (that is, the weight of the atmosphere) ought by itself alone to offer a greater resistance than it does when we try to produce a vacuum."

It was traditionally thought (especially by the Aristotelians) that the air did not have lateral weight: that is, that the miles of air above us don't weigh down on the air at our level. Even Galileo had accepted the weightlessness of air as a simple truth. Torricelli questioned that assumption, and instead proposed that the air had weight, and that it was the weight of the air (not the attracting force of the vacuum) which held (or rather, pushed) up the column of water. He thought that the level the water stayed at (thirty-four feet) was reflective of the force of the air's weight pushing on it (specifically, pushing on the water in the basin and thus limiting how much water can fall from the tube into it). In other words, he viewed the barometer as a balance, an instrument for measurement (as opposed to merely being an instrument to create a vacuum), and because he was the first to view it this way, he is traditionally considered the inventor of the barometer (in the sense in which we use the term now).


Left: A 1644 rendition of experiments of Torricelli on making a vacuum by means of a mercury column, Florence. [12] Right: A depiction of one of Blaise Pascal's vacuum experiments, using a water column, in the city of Rouen, France. [14]

In 1643, Galileo Galilei, believing that Aristotle’s horror vacui postulate was true, but to within limits, encouraged his pupil Evangelista Torricelli to investigate the subject. Pumps operating in mines had already proven that nature would only fill a vacuum with water up to a height of thirty feet. Knowing this curious fact, Galileo encourages his former pupil, Torricelli to investigate these supposed limitations. Torricelli did not believe that vacuum abhorrence was responsible for raising the water. Rather, he reasoned, it was the result of the pressure exerted on the liquid by the surrounding air. To prove this theory, he filled a glass tube, sealed at one end, filled with mercury and upended it into a dish also containing mercury, as shown adjacent. Torricelli found that only a portion of the tube emptied, as shown above; thirty inches of the liquid remained. As the mercury emptied, a vacuum was created at the top of the tube. This barometer-type vacuum effectively disproved Aristotle’s theory and affirmed the existence of vacuums in nature.

Due to rumors circulating within Torricelli's gossipy Italian neighborhood, which included that he was up to some form of sorcery or witchcraft, Torricelli realized he had to keep his experiment more secretive, or run the risk of being arrested. He needed to use a liquid that was heavier than water, and from his previous association and suggestions by Galileo, he deduced by using mercury, a shorter tube could be used. With the use of mercury, then called "quicksilver", which is about 14 times heavier than water, a tube only 32 inches was now needed, not 35 feet.
Pascal's water/wine experiments
In 1646, Blaise Pascal along with Pierre Petit, had repeated and perfected Torricelli's experiment after hearing about it from Marin Mersenne, who himself had been shown the experiment by Torricelli toward the end of 1644. Pascal further devised an experiment to test the Aristotelian proposition that it was vapors from the liquid that filled the space in a barometer. His experiment compared water with wine, and since the latter was considered more 'spiritous', the Aristotelian's expected the wine to stand lower (since more vapors would mean more pushing against the liquid column).

Pascal performed his version of the vacuum experiment in front of 500 people. He used hoses of 10 meters' length hoisted by a ship's mast, as depicted above. [14]

Pascal performed the experiment publicly, inviting the Aristotelians to predict the outcome beforehand. The Aristotelians predicted the wine would stand lower. It did not. However, Pascal went even further to test the mechanical theory. If, as suspected by mechanical philosophers like Torricelli and Pascal, air had lateral weight, the weight of the air would be less in higher altitudes.

Therefore, Pascal wrote to his brother-in-law, Florin Perier, living near the mountain called the Puy de Dome, requesting that the latter perform a crucial experiment. Perier was instructed to take a barometer up the Puy de Dom and make measurements along the way of how high the column of mercury stood. He was then to compare it to measurements taken at the foot of the mountain to see if those measurements taken higher up were in fact smaller.


Above: a 16-horse demonstration of German engineer Otto Guericke's 1654 Magdeburg hemispheres, spheres with a mechanically-made vacuum inside (made using a vacuum pump), invented to disprove Greek philosopher Parmenides' circa 485BC "nature abhors a vacuum" (horror vacui) postulate; below: a statue of Guericke's famous vacuum demonstration proof in Altstadt, Magdeburg, Germany. [6]

Magdeburg hemispheres (illustration + monument)

Above: a 16-horse demonstration of German engineer Otto Guericke's 1654 Magdeburg hemispheres, spheres with a mechanically-made vacuum inside (made using a vacuum pump), invented to disprove Greek philosopher Parmenides' circa 485BC "nature abhors a vacuum" (horror vacui) postulate; below: a statue of Guericke's famous vacuum demonstration proof in Altstadt, Magdeburg, Germany. [6]

In September of 1648, Perier carefully and meticulously carried out the experiment, and found that Pascal's predictions had been correct. The mercury barometer stood lower the higher one went.

Guericke vacuums
In vacuum theory and experiment history German engineer Otto Guericke has cogently been described as one of the "giants" in the history of the subject. [14] It has been surmised that Guericke heard about or been stimulated or influenced in some way or another by the synergy of these Galileo-Torricelli vacuum investigations. [10] Guericke translated Aristotle's definition of the void as follows: [14]

"A void is a space that is not taken up by any extended object, but that is capable of being filled with such objects."

In circa 1649, Guericke attempted to make a vacuum in a beer keg, as depicted adjacent.

This experiment lead to the invention of the vacuum pump and in 1654 to the famous demonstration of the the Magdeburg hemispheres, vacuum containing copper spheres invented to prove that vacuums can exist in nature.

Pneumatical engine
Guericke's vacuum pump invention led to the development of the the pneumatical engine (pictured adjacent), build by Robert Hooke, under the direction of Robert Boyle, in 1658. This experimental device lead to the ideal gas law.


The pneumatical engine, used to make a partial vacuum (of various measurable pressures) in the detachable glass bulb H, built by Robert Hooke in 1658, under the direction of Robert Boyle, based on Otto Guericke's earlier vacuum pump designs, a device that led first to Boyle's law, then to the various gas laws, and eventually to the ideal gas law.

The pneumatical engine, used to make a partial vacuum (of various measurable pressures) in the detachable glass bulb H, built by Robert Hooke in 1658, under the direction of Robert Boyle, based on Otto Guericke's earlier vacuum pump designs, a device that led first to Boyle's law, then to the various gas laws, and eventually to the ideal gas law.

Gravity
In 1662, a nineteen-year-old college student named Isaac Newton, in his second year at University of Cambridge, was becoming self-educated through his voracious reading habit, had heard of both Evangelista Torricelli's 1643 barometer invention or "Torricelli vacuum" experiment as well as Robert Boyle’s recent experiments with an air pump-vacuum, and began fill out a notebook (section: Some Philosophical Questions) with 45 philosophical queries, one of which was entitled “The Flux and Reflux of the Sea”, in which he outline an experiment in which mercury barometer could be used to test the then-prevalent theory that the tides were caused by the moon’s “pressing the atmosphere”, as it had been believed. Newton wrote:

“[Fill a tube with mercury or water; seal the top]; “the liquor will sink three or four inches below it leaving a vacuum (perhaps)”; [then as the air is pressed by the moon, see if the water will rise or fall].”

The completion of his 1687 Principia, which contained the three laws of motion and the law of universal gravitation, would eventually disprove the moon pressure gravity theory.

In 1726, a year before Newton’s end (death), after being released from the Bastille (jail), on the condition that he go to England, French science-philosopher and writer Voltaire went to London, where he occupied himself mainly with mathematics and made himself familiar with the philosophy of Newton, where he remained for a period of three years. Upon arrival he reported that: [15]

“For us [Cartesian-based French science] it is the pressure of the moon that causes the tides of the sea; for the English [Newtonian-based science] it is the sea that gravitates towards the moon, so that when you think that the moon should give a high tide, these gentleman think you should have a low one.”

Hence, over the course of 65-years, starting from some loose outline queries in a college notebook, in regards to using a vacuum-making device to test Rene Descartes impulse theory of moon induced tide variations, Newton had revolutionized the way the operation of the universe was viewed.


An 1682 demonstration of Christiaan Huygens gunpowder engine, where a dram of gunpowder created enough vacuum to lift 7-8 boys into the air.

Huygens gun powder engine (lifting boys)

An 1682 demonstration of Christiaan Huygens gunpowder engine, where a dram of gunpowder created enough vacuum to lift 7-8 boys into the air.

Perfect vacuum
Building on the work of Hooke and Boyle, in 1678 Dutch mathematical physicist Christiaan Huygens invented the gunpowder engine, which worked by driving out the air of the cylinder during the explosion though one-way valves after which a partial vacuum in respect to the surrounding atmosphere was created inside the cylinder, to result in the piston being pushed down by the atmosphere to eliminate the vacuum. The aim of these endeavors was to create the so-called "perfect vacuum". The fowling of the explosion (products left over at the end of the explosion), supposedly, is what was said to prevent the perfect vacuum from resulting.

Steam engine
In 1690, after experimenting with gunpowder engine designs (with Huygens), French physicist Denis Papin drew out the designs for the steam engine (Papin engine) based on the idea of quickly cooling a body of steam in a piston and cylinder, resulting to create a vacuum, and drive the piston down.

Thermodynamics
Much of the theoretical structure of the follow-up science of thermodynamics, the subject of physics that arose to explain the operation of Papin's basic heat engine design, is based around this concept and explanation of "vacuum creation", whenever a body is quickly cooled, such as embodied in the notion of pressure volume work (PV work).


A 2006 section on nature abhors a vacuum in the context of the physical chemistry of liquids: enthalpy and entropy terms. [9]

A 2006 section on nature abhors a vacuum in the context of the physical chemistry of liquids: enthalpy and entropy terms. [9]

Physical chemistry
In physical chemistry, nature abhors a vacuum is sometimes explained in enthalpy and entropy terms, as discussed adjacent (in terms of liquids vs solids). [9]

Modern views
German physicist Henning Genz argues in his 1994 book Nothingness: the Science of Empty Space that quantum mechanics and particle physics make or indicate that a complete vacuum is impossible. [14]

In the 2005 book Into the Cool: Energy Flow, Thermodynamics, and Life, science writers Eric Schneider and Dorion Sagan twist the idiom around to argue that "nature abhors a gradient." [5]

In the 2007 book The Void, English particle physicist Frank Close gives a detailed history of the subject of "nature abhors a vacuum" and speculates on how the subject may be making a return in the concept of the Higgs field. [7]

References
1. Thims, Libb. (2007). Human Chemistry (Volume One) (section: Vacuums in nature, pgs. 46-47). Morrisville, NC: LuLu.
2. Nature abhors a vacuum – UsingEnglish.com.
3. History of the barometer – Strange-Loops.com.
4. Torricelli, Evangelista. (1644). “Letter to Michelangelo Ricci concerning Barometer”, June 11, Florence, Italy. In: Collected Works Vol. III (1919) [from William Francis Magie, A Source Book in Physics (New York: McGraw-Hill, 1935)].
5. Schneider, Eric D. and Sagan, Dorion. (2005). Into the Cool: Energy Flow, Thermodynamics, and Life. University of Chicago Press.
6. Von Guericke, Otto. Encyclopaedia Britannica, 11th Edition 9. (1910). The Encyclopaedia Britannica. 670.
7. Close, Frank. (2007). The Void. Oxford University Press.
8. Johnstone, James. (1921). The Mechanism of Life in Relation to Modern Physical Theory (pg. 161). Longmans, Green & Co.
9. Anslyn, Eric V and Dougherty, Dennis A. (2006). Modern Physical Organic Chemistry (§3.1.1: Nature Abhors a Vacuum, pg. 146). University Science Books.
10. Craik, George L. (1831). The Pursuit of Knowledge under Difficulties (pg. 81). C. Knight.
11. (a) The Vacuum – RadicalArt.info.
(b) Raffaello Magiotti: Letter to Marin Mersenne. March, 1648.
(c) Gaspar Schott: Technica curiosa, sive, Mirabilia artis. Würzburg 1664.
12. (a) The Vacuum – RadicalArt.info.
(b) Torricelli, Evangelista. (1644). " Letter to Michelangelo Ricci concerning the Barometer," June 11. In: Collected Works Vol. III (1919). Also in: William Francis Magie: A Source Book in Physics (New York: McGraw-Hill, 1935).
(c) Middleton, W.E.K. (1964). The History of the Barometer (pp. 23-30). Baltimore: Johns Hopkins Press.
13. (a) Boschiero, Luciano. (2007). Experimental and Natural Philosophy in Seventeenth-century Tuscany (pg. 118). Springer.
(b) Galilei, Galileo. (date). Discorsi e dimostraziono Matematiche Intorno a due Nuove Scienze Attenenti all Meccanica and I Movimenti Locali; in: Leida: Appresso gli Elsevirii, 1638, 15.
14. Genz, Henning (1994). Nothingness, the Science of Empty Space (translated from German by Karin Heusch) (Pascal, pg. 28; Guericke, pg. 44). Perseus Book Publishing, 1999.
15. Gleick, James. (2003). Isaac Newton (pgs. 28-31). Vintage Books.

Further reading
● Grant, Edward. (1981). Much Ado About Nothing: Theories of Space and Vacuum from the Middle Ages to the Scientific Revolution. Cambridge University Press.
● Schmitt, Charles B. (1967). “Experimental Evidence for and Against a Void: the Sixteenth-Century Arguments” (abs), Isis, 58(3):352-66.

External links
● Horror vacui (physics) – Wikipedia.
● The Vacuum – RadicalArt.info.