Vacuum - Knowledge (XXG)

2308: 1360: 2217: 2154:, and their outgassing becomes important when the vacuum pressure falls below this vapour pressure. Outgassing has the same effect as a leak and will limit the achievable vacuum. Outgassing products may condense on nearby colder surfaces, which can be troublesome if they obscure optical instruments or react with other materials. This is of great concern to space missions, where an obscured telescope or solar cell can ruin an expensive mission. 412: 1229: 51: 1887: 685: 570: 1745: 2213:, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed cavity to create a vacuum. Because of the pressure differential, some fluid from the chamber (or the well, in our example) is pushed into the pump's small cavity. The pump's cavity is then sealed from the chamber, opened to the atmosphere, and squeezed back to a minute size. 1814:) consist of a vertical column of liquid in a tube whose ends are exposed to different pressures. The column will rise or fall until its weight is in equilibrium with the pressure differential between the two ends of the tube. The simplest design is a closed-end U-shaped tube, one side of which is connected to the region of interest. Any fluid can be used, but 265:, however, even the abstract concept of a featureless void faced considerable skepticism: it could not be apprehended by the senses, it could not, itself, provide additional explanatory power beyond the physical volume with which it was commensurate and, by definition, it was quite literally nothing at all, which cannot rightly be said to exist. 374: 1878:

measured, corrosion and surface deposits. Their calibration can be invalidated by activation at atmospheric pressure or low vacuum. The composition of gases at high vacuums will usually be unpredictable, so a mass spectrometer must be used in conjunction with the ionization gauge for accurate measurement.

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This shallow water well pump reduces atmospheric air pressure inside the pump chamber. Atmospheric pressure extends down into the well, and forces water up the pipe into the pump to balance the reduced pressure. Above-ground pump chambers are only effective to a depth of approximately 9 meters due to

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produced the first laboratory vacuum in 1643, and other experimental techniques were developed as a result of his theories of atmospheric pressure. A Torricellian vacuum is created by filling with mercury a tall glass container closed at one end, and then inverting it in a bowl to contain the mercury

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Cold or oxygen-rich atmospheres can sustain life at pressures much lower than atmospheric, as long as the density of oxygen is similar to that of standard sea-level atmosphere. The colder air temperatures found at altitudes of up to 3 km generally compensate for the lower pressures there. Above

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Animal experiments show that rapid and complete recovery is normal for exposures shorter than 90 seconds, while longer full-body exposures are fatal and resuscitation has never been successful. A study by NASA on eight chimpanzees found all of them survived two and a half minute exposures to vacuum.

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Deep wells have the pump chamber down in the well close to the water surface, or in the water. A "sucker rod" extends from the handle down the center of the pipe deep into the well to operate the plunger. The pump handle acts as a heavy counterweight against both the sucker rod weight and the weight

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is used in the study of atomically clean substrates, as only a very good vacuum preserves atomic-scale clean surfaces for a reasonably long time (on the order of minutes to days). High to ultra-high vacuum removes the obstruction of air, allowing particle beams to deposit or remove materials without

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version an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The current depends on the number of ions, which depends on the pressure in the gauge. Hot cathode

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In other words, most low vacuum gauges that read, for example 50.79 Torr. Many inexpensive low vacuum gauges have a margin of error and may report a vacuum of 0 Torr but in practice this generally requires a two-stage rotary vane or other medium type of vacuum pump to go much beyond (lower

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The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an

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maintaining an internal pressure of 1 atmosphere submerged to a depth of 10 atmospheres (98 metres; a 9.8-metre column of seawater has the equivalent weight of 1 atm) is effectively a vacuum chamber keeping out the crushing exterior water pressures, though the 1 atm inside the submarine would

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is generally much more empty than any artificial vacuum. It may or may not meet the definition of high vacuum above, depending on what region of space and astronomical bodies are being considered. For example, the MFP of interplanetary space is smaller than the size of the Solar System, but larger

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version is the same, except that electrons are produced in a discharge created by a high voltage electrical discharge. Cold cathode gauges are accurate from 10 torr to 10 torr. Ionization gauge calibration is very sensitive to construction geometry, chemical composition of gases being

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which isolates a known volume of vacuum and compresses it to multiply the height variation of the liquid column. The McLeod gauge can measure vacuums as high as 10 torr (0.1 mPa), which is the lowest direct measurement of pressure that is possible with current technology. Other vacuum

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within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pressure of blood vessels ensures that this boiling point remains above the

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Ultra-high vacuum systems are usually baked, preferably under vacuum, to temporarily raise the vapour pressure of all outgassing materials and boil them off. Once the bulk of the outgassing materials are boiled off and evacuated, the system may be cooled to lower vapour pressures and minimize

1523:(MFP) of residual gases, which indicates the average distance that molecules will travel between collisions with each other. As the gas density decreases, the MFP increases, and when the MFP is longer than the chamber, pump, spacecraft, or other objects present, the continuum assumptions of 1232: 2101:) are typically vacuum-powered, as protection against loss of all (electrically powered) instruments, since early aircraft often did not have electrical systems, and since there are two readily available sources of vacuum on a moving aircraft, the engine and an external venturi. 369:

and more implicitly, the spatial–corporeal component of his metaphysics would come to define the philosophically modern notion of empty space as a quantified extension of volume. By the ancient definition however, directional information and magnitude were conceptually distinct.

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astronauts wore a fitted elastic garment called the Crew Altitude Protection Suit (CAPS) which prevents ebullism at pressures as low as 2 kPa (15 Torr). Rapid boiling will cool the skin and create frost, particularly in the mouth, but this is not a significant hazard.

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The above explanation is merely a simple introduction to vacuum pumping, and is not representative of the entire range of pumps in use. Many variations of the positive displacement pump have been developed, and many other pump designs rely on fundamentally different principles.

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Pressure can be achieved by sophisticated materials (e.g. vacuum fired low-carbon stainless steel, aluminium, copper-beryllium, titanium), metal sealings, special surface preparations and cleaning, bake-out and additional getter pumps; molecular flow regime for gases

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can capture gases in a solid or absorbed state, often with no moving parts, no seals and no vibration. None of these pumps are universal; each type has important performance limitations. They all share a difficulty in pumping low molecular weight gases, especially

2258:. And sometimes, the final pressure is not the only relevant characteristic. Pumping systems differ in oil contamination, vibration, preferential pumping of certain gases, pump-down speeds, intermittent duty cycle, reliability, or tolerance to high leakage rates. 1134: 2201:. Suction can spread and dilute a vacuum by letting a higher pressure push fluids into it, but the vacuum has to be created first before suction can occur. The easiest way to create an artificial vacuum is to expand the volume of a container. For example, the 346:, which required there to be no restrictions on the powers of God, led to the conclusion that God could create a vacuum if he so wished. From the 14th century onward increasingly departed from the Aristotelian perspective, scholars widely acknowledged that a 1045: 2124:

is used for this purpose. The typical vacuum maintained in the condenser steam space at the exhaust of the turbine (also called condenser backpressure) is in the range 5 to 15 kPa (absolute), depending on the type of condenser and the ambient conditions.

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into the idea of a vacuum considered whether a vacuum was present, if only for an instant, between two flat plates when they were rapidly separated. There was much discussion of whether the air moved in quickly enough as the plates were separated, or, as

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Vacuum quality is subdivided into ranges according to the technology required to achieve it or measure it. These ranges were defined in ISO 3529-1:2019 as shown in the following table (100 Pa corresponds to 0.75 Torr; Torr is a non-SI unit):

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Therefore, to properly understand the following discussions of vacuum measurement, it is important that the reader assumes the relative measurements are being done on Earth at sea level, at exactly 1 atmosphere of ambient atmospheric pressure.

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The kenotometer is a particular type of hydrostatic gauge, typically used in power plants using steam turbines. The kenotometer measures the vacuum in the steam space of the condenser, that is, the exhaust of the last stage of the turbine.

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must be considered. Some oils and greases will boil off in extreme vacuums. The permeability of the metallic chamber walls may have to be considered, and the grain direction of the metallic flanges should be parallel to the flange face.

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attempted to detect a minute drag on the Earth's orbit. While the Earth does, in fact, move through a relatively dense medium in comparison to that of interstellar space, the drag is so minuscule that it could not be detected. In 1912,

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by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 32 millipascals

1855:(RTD) can then be used to measure the temperature of the filament. This temperature is dependent on the rate at which the filament loses heat to the surrounding gas, and therefore on the thermal conductivity. A common variant is the 1841:, in which the diaphragm makes up a part of a capacitor. A change in pressure leads to the flexure of the diaphragm, which results in a change in capacitance. These gauges are effective from 10 torr to 10 torr, and beyond. 2183: 2157:

The most prevalent outgassing product in vacuum systems is water absorbed by chamber materials. It can be reduced by desiccating or baking the chamber, and removing absorbent materials. Outgassed water can condense in the oil of

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has very low density and pressure, and is the closest physical approximation of a perfect vacuum. But no vacuum is truly perfect, not even in interstellar space, where there are still a few hydrogen atoms per cubic meter.

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and sinuses may be ruptured by rapid decompression, soft tissues may bruise and seep blood, and the stress of shock will accelerate oxygen consumption leading to hypoxia. Injuries caused by rapid decompression are called

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Rapid decompression can be much more dangerous than vacuum exposure itself. Even if the victim does not hold his or her breath, venting through the windpipe may be too slow to prevent the fatal rupture of the delicate

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wrote a treatise rejecting the existence of the vacuum in the 10th century. He concluded that air's volume can expand to fill available space, and therefore the concept of a perfect vacuum was incoherent. According to

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which uses a single platinum filament as both the heated element and RTD. These gauges are accurate from 10 torr to 10 torr, but they are sensitive to the chemical composition of the gases being measured.

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gauges can measure lower pressures, but only indirectly by measurement of other pressure-controlled properties. These indirect measurements must be calibrated via a direct measurement, most commonly a McLeod gauge.

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commented: "While the interstellar absorbing medium may be simply the ether, is characteristic of a gas, and free gaseous molecules are certainly there". Thereafter, however, luminiferous aether was discarded.

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are zero. This means that this region is devoid of energy and momentum, and by consequence, it must be empty of particles and other physical fields (such as electromagnetism) that contain energy and momentum.

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Pressure can be achieved by elaborate materials (e.g. low-carbon stainless steel), metal sealings, special surface preparations and cleaning, bake-out and high vacuum pumps; molecular flow regime for gases

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expands the chest cavity, which causes the volume of the lungs to increase. This expansion reduces the pressure and creates a partial vacuum, which is soon filled by air pushed in by atmospheric pressure.

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To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind

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is preferred for its high density and low vapour pressure. Simple hydrostatic gauges can measure pressures ranging from 1 torr (100 Pa) to above atmospheric. An important variation is the

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than small planets and moons. As a result, solar winds exhibit continuum flow on the scale of the Solar System, but must be considered a bombardment of particles with respect to the Earth and Moon.

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and must fire their engines every couple of weeks or a few times a year (depending on solar activity). The drag here is low enough that it could theoretically be overcome by radiation pressure on

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While outer space provides the most rarefied example of a naturally occurring partial vacuum, the heavens were originally thought to be seamlessly filled by a rigid indestructible material called

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The quality of a vacuum is indicated by the amount of matter remaining in the system, so that a high quality vacuum is one with very little matter left in it. Vacuum is primarily measured by its

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QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains

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gauges depend on a Bourdon tube, diaphragm, or capsule, usually made of metal, which will change shape in response to the pressure of the region in question. A variation on this idea is the

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But although it meets the definition of outer space, the atmospheric density within the first few hundred kilometers above the Kármán line is still sufficient to produce significant

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is always exactly true. For example, the electric potential generated by two charges is the simple addition of the potentials generated by each charge in isolation. The value of the

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experiment, showing that, owing to atmospheric pressure outside the hemispheres, teams of horses could not separate two hemispheres from which the air had been partially evacuated.

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believed that no void could occur naturally, because the denser surrounding material continuum would immediately fill any incipient rarity that might give rise to a void. In his

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There is only a limited amount of data available from human accidents, but it is consistent with animal data. Limbs may be exposed for much longer if breathing is not impaired.

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are necessary to prevent ebullism above 19 km. Most spacesuits use only 20 kPa (150 Torr) of pure oxygen. This pressure is high enough to prevent ebullism, but

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gauges rely on the fact that the ability of a gas to conduct heat decreases with pressure. In this type of gauge, a wire filament is heated by running current through it. A

1720:, typically as a subtraction relative to ambient atmospheric pressure on Earth. But the amount of relative measurable vacuum varies with local conditions. On the surface of 329:

in the 13th and 14th century focused considerable attention on issues concerning the concept of a vacuum. The commonly held view that nature abhorred a vacuum was called

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chambers, common in chemistry, physics, and engineering, operate below one trillionth (10) of atmospheric pressure (100 nPa), and can reach around 100 particles/cm.

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10 torrs (6.7 fPa) have been indirectly measured in a 4 K (−269.15 °C; −452.47 °F) cryogenic vacuum system. This corresponds to ≈100 particles/cm.

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Wheeler, R.M.; Wehkamp, C.A.; Stasiak, M.A.; Dixon, M.A.; Rygalov, V.Y. (2011). "Plants survive rapid decompression: Implications for bioregenerative life support".

1792:(mmHg) or pascals (Pa) below standard atmospheric pressure. "Below atmospheric" means that the absolute pressure is equal to the current atmospheric pressure. 4617:

Ferl, RJ; Schuerger, AC; Paul, AL; Gurley, WB; Corey, K; Bucklin, R (2002). "Plant adaptation to low atmospheric pressures: Potential molecular responses".

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and reduce their net speed drastically if gas ballasting is not used. High vacuum systems must be clean and free of organic matter to minimize outgassing.

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for vacuum experiments, used in science education during the early 20th century, on display in the Schulhistorische Sammlung ('School Historical Museum'),

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The fundamental state of minimum energy, the vacuum, is not unique and there are a continuum of degenerate states that altogether respect the symmetry...

1411:, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to 1306:. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include 2307: 275:, book IV, Aristotle offered numerous arguments against the void: for example, that motion through a medium which offered no impediment could continue 2233:, which bear some similarities to dynamic pumps used at higher pressures, can achieve much higher quality vacuums than positive displacement pumps. 504:). Early theories of light posited a ubiquitous terrestrial and celestial medium through which light propagated. Additionally, the concept informed 3533: 2313: 1610:

Pressure can be achieved by elaborate materials (e.g. stainless steel), elastomer sealings and high vacuum pumps; molecular flow regime for gases

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Pressure can be achieved by elaborate materials (e.g. stainless steel) and positive displacement vacuum pumps; transitional flow regime for gases

556:, or energy and time can be measured. This far reaching consequences also threatened whether the "emptiness" of space between particles exists. 1244: 1329:

is thought to have arisen from transitions between different vacuum states. For theories obtained by quantization of a classical theory, each

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The Quantum Vacuum: A Scientific and Philosophical Concept, from Electrodynamics to String Theory and the Geometry of the Microscopic World

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Cooke, J.P.; Bancroft, R.W. (1966). "Some cardiovascular responses in anesthetized dogs during repeated decompressions to a near-vacuum".

4919: 3391: 3232: 1291:.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next. 3322: 3295: 1581:

Pressure can be achieved by simple materials (e.g. regular steel) and positive displacement vacuum pumps; viscous flow regime for gases

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of void and atom. Although Descartes agreed with the contemporary position, that a vacuum does not occur in nature, the success of his

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is an even higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space.

809:(with zero electric charge) is an elegant example of a region completely "filled" with vacuum, but still showing a strong curvature. 4937: 1667: 768: 653: 2411:. A pressure drop of 13 kPa (100 Torr), which produces no symptoms if it is gradual, may be fatal if it occurs suddenly. 4973: 3823:

Returning to the vacuum of a relativistic field theory, we find that both paramagnetic and diamagnetic contributions are present.

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processes are industrially important for production of certain grades of steel or high purity materials. The elimination of air

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An experiment indicates that plants are able to survive in a low pressure environment (1.5 kPa) for about 30 minutes.

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is necessarily flat: the gravitational field can still produce curvature in a vacuum in the form of tidal forces and

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Jönsson, K. Ingemar; Rabbow, Elke; Schill, Ralph O.; Harms-Ringdahl, Mats & Rettberg, Petra (9 September 2008).

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Clemens Timpler: Physicae seu philosophiae naturalis systema methodicum. Pars prima; complectens physicam generalem

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becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or

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to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for

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with 1 torr equaling 133.3223684 pascals above absolute zero pressure. Vacuum is often also measured on the

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In effect, the dielectric permittivity of the vacuum of classical electromagnetism is changed. For example, see

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Although the blood will not boil, the formation of gas bubbles in bodily fluids at reduced pressures, known as

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further developed vacuum pump technology. Thereafter, research into the partial vacuum lapsed until 1850 when

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also proposed a geometrically based alternative theory of atomism, without the problematic nothing–everything

833:, is a standard reference medium for electromagnetic effects. Some authors refer to this reference medium as 2599: 2143: 2040: 2007: 1906: 1890: 1546:) the MFP of room temperature air is roughly 100 mm, which is on the order of everyday objects such as 1342: 1268: 944: 880: 702: 587: 521: 187: 36: 3076:

Gabrielse, G.; Fei, X.; Orozco, L.; Tjoelker, R.; Haas, J.; Kalinowsky, H.; Trainor, T.; Kells, W. (1990).

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Billings, Charles E. (1973). "Chapter 1) Barometric Pressure". In Parker, James F.; West, Vita R. (eds.).

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systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of

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The strictest criterion to define a vacuum is a region of space and time where all the components of the

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used vacuum instead of pressure to drive a piston. In the 19th century, vacuum was used for traction on

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Many devices are used to measure the pressure in a vacuum, depending on what range of vacuum is needed.

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of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas

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Beckwith, Thomas G.; Roy D. Marangoni & John H. Lienhard V (1993). "Measurement of Low Pressures".

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The vacuum of classical electromagnetism can be viewed as an idealized electromagnetic medium with the

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Much ado about nothing: theories of space and vacuum from the Middle Ages to the scientific revolution

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Similarly, much higher than normal relative vacuum readings are possible deep in the Earth's ocean. A

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in this range has large gradients of pressure, temperature and composition, and varies greatly due to

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proposed a model of the vacuum as an infinite sea of particles possessing negative energy, called the

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Ishimaru, H (1989). "Ultimate Pressure of the Order of 10 torr in an Aluminum Alloy Vacuum Chamber".

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is one of the few words in the English language that contains two consecutive instances of the vowel

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residual outgassing during actual operation. Some systems are cooled well below room temperature by

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void exists beyond the confines of the cosmos itself by the 17th century. This idea, influenced by

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Historically, there has been much dispute over whether such a thing as a vacuum can exist. Ancient

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invented the mercury displacement pump, achieving a partial vacuum of about 10 Pa (0.1

392: 255: 343: 335:. There was even speculation that even God could not create a vacuum if he wanted and the 1277 4933: 4824: 4803: 4694: 4626: 4553: 4543: 4485: 4458: 4341: 4294: 4271: 4261: 4122: 4093: 4085: 4063: 4035: 4027: 3917: 3911: 3858: 3812: 3792: 3772: 3766: 3744: 3709: 3703: 3682: 3674: 3653: 3513: 3488: 3478: 3453: 3443: 3388: 3271: 3261: 3186: 3108: 3060: 3048: 3021: 2998: 2988: 2939: 2371: 2334: 2262: 2098: 2086: 2060: 1926: 1815: 1785: 1512: 1408: 1299: 1252: 545: 478: 450: 436: 381: 358: 195: 178:(1605) philosophized about the experimental possibility of producing a vacuum in small tubes. 156: 4114: 4057: 3844: 3806: 3786: 3734: 3645: 3472: 3042: 4750: 4746: 4684: 4597: 4589: 4431: 4378: 4216: 3621: 3205: 3160: 3100: 2927: 2544: 2159: 2121: 2056: 1991: 1905:

Vacuum is useful in a variety of processes and devices. Its first widespread use was in the

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states that "there is no observable evidence that rules out the possibility of vacuum". The

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This article is about empty physical space or the absence of matter. For the appliance, see

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Webb P. (1968). "The Space Activity Suit: An Elastic Leotard for Extravehicular Activity".

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The Book of Nothing: Vacuums, Voids, and the Latest Ideas About the Origins of the Universe

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The Book of Nothing: Vacuums, Voids, and the Latest Ideas about the Origins of the Universe

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are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the

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has raised interest in the impact of vacuum on human health, and on life forms in general.

4953: 4929: 3395: 3211: 2877: 2871: 2375: 2167: 2151: 2066: 2011: 1951: 1947: 1524: 1451: 175: 3558: 194:, and a wide array of vacuum technologies has since become available. The development of 102:) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous 4907: 4875: 4680: 4585: 4374: 3854: 3617: 3142: 3096: 4968: 4914: 4536: 4007:

The NIST reference on constants, units, and uncertainty: Fundamental physical constants

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The NIST reference on constants, units, and uncertainty: Fundamental physical constants

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The NIST reference on constants, units, and uncertainty: Fundamental physical constants

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The NIST reference on constants, units, and uncertainty: Fundamental physical constants

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is variable but 101.325 and 100 kilopascals (1013.25 and 1000.00 mbar) are common

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Quantum Field Theory III: Gauge Theory: A Bridge Between Mathematicians and Physicists

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The relative permeability and permittivity of field-theoretic vacuums is described in

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The reasoning for the definition of the ranges is as follows (typical circumstances):

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In the theory of classical electromagnetism, free space has the following properties:

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Vacuum became a valuable industrial tool in the 20th century with the introduction of

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Theoretically, in QCD multiple vacuum states can coexist. The starting and ending of

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The 17th century saw the first attempts to quantify measurements of partial vacuum.

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Introduction to Quantum Optics: From the Semi-Classical Approach to Quantized Light

2916: 2882: 2658: 2415: 2387: 2360: 2322: 2078: 2048: 1922: 1914: 1874: 1856: 1848: 1819: 1428: 1260: 1223: 895: 790: 505: 500:, aether came to be regarded as the rarefied air from which it took its name, (see 474: 466: 462: 416: 401: 347: 292: 283: 279:, there being no reason that something would come to rest anywhere in particular. 3600:"Solar system, the motion of the, relatively to the interstellar absorbing medium" 250:, which posited void and atom as the fundamental explanatory elements of physics. 50: 4818: 4797: 3507: 4256:

John H., Moore; Christopher Davis; Michael A. Coplan & Sandra Greer (2002).

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For a qualitative description of vacuum fluctuations and virtual particles, see

3559:"Otto von Guericke | Prussian physicist, engineer, and philosopher | Britannica" 3156: 3129:

Tadokoro, M. (1968). "A Study of the Local Group by Use of the Virial Theorem".

3104: 2904: 2842: 2684: 2434: 2347: 2234: 2230: 2210: 2192: 2139: 1987: 1939: 1886: 1696: 1547: 1536: 1516: 1482: 1391: 1354: 802: 684: 569: 454: 420: 318: 191: 160: 127: 59: 3995: 155:

to reduce air pressure by around 20%. But higher-quality vacuums are possible.

4689: 4664: 4645: 4593: 3878: 3834: 3826: 3290: 2936:– controlling loose magnetic tape in early computer data recording tape drives 2422: 2408: 2147: 2134: 2074: 1999: 1979: 1963: 1781: 1744: 1684: 1494: 1455: 1424: 1399: 1311: 1280: 1272: 1219: 1215: 842: 838: 806: 794: 529: 518: 509: 123: 17: 3626: 1575:

Prevailing atmospheric pressure (31 kPa to 110 kPa) to 100 Pa

258:

tried unsuccessfully to create an artificial vacuum in the first century AD.

4602: 4557: 4435: 4404: 4293:(Fifth ed.). Reading, Massachusetts: Addison-Wesley. pp. 591–595. 4275: 3457: 3415: 3275: 3002: 2487: 2379: 2270: 2266: 1811: 1773: 1769: 1728: 1532: 1447: 1439:

to describe these environments, in units of particles per cubic centimetre.

533: 439: 384: 362: 307: 287: 266: 251: 4777: 4698: 4630: 4154: 3112: 4720: 4489: 4462: 3736:

The cosmic landscape: string theory and the illusion of intelligent design

1283:. QED vacuum is a state with no matter particles (hence the name), and no 709: in this subsection. Unsourced material may be challenged and removed. 594: in this subsection. Unsourced material may be challenged and removed. 404:

reported in the 14th century that teams of ten horses could not pull open

2922: 2750: 2343: 2274: 2239: 2171: 2003: 1971: 1898: 1717: 1692: 1478: 1372: 925: 873: 553: 541: 310:

in the 13th century, and later appeared in Europe from the 15th century.

144: 103: 55: 4898: 3346:"The Interplay of Science and Theology in the Fourteenth-century Kalam" 2910: 2901:– transport system using vacuum or pressure to move containers in tubes 2893: 2403: 2198: 2090: 2032: 1873:

gauges are accurate from 10 torr to 10 torr. The principle behind

1515:, but a complete characterization requires further parameters, such as 1490: 405: 300: 247: 152: 4505:"The Effect on the Chimpanzee of Rapid Decompression to a near Vacuum" 3348:. From Medieval to Modern in the Islamic World, Sawyer Seminar at the 2363:

was the first to show in 1660 that vacuum is lethal to small animals.

2182: 1519:

and chemical composition. One of the most important parameters is the

536:. This theory helped refine the predictions of his earlier formulated 400:

postulated, whether a 'celestial agent' prevented the vacuum arising.

4920:"Much Ado About Nothing" by Professor John D. Barrow, Gresham College 4646:"EBULLISM AT 1 MILLION FEET: Surviving Rapid/Explosive Decompression" 4382: 4340:(3rd ed.). Van Nostrand Reinhold, New York. pp. 1278–1284. 3185:. Hildesheim / Zürich / New York: Georg Olms Verlag. pp. 28–37. 2788: 2243: 2187:

of the water column standing on the upper plunger up to ground level.

1688: 1683:

is an ideal state of no particles at all. It cannot be achieved in a

1486: 1470: 1380: 1376: 1284: 891:

sum of the two electric fields from each of the charges acting alone.

493: 340: 110:. Physicists often discuss ideal test results that would occur in a 87: 4849: 4314: 4220: 3599: 2197:

Fluids cannot generally be pulled, so a vacuum cannot be created by

2017: 1427:, so the definition of pressure becomes difficult to interpret. The 2281:

The lowest pressures currently achievable in laboratory are about 1

4870: 4865: 4151:

Thermal Protection Systems Expert and Material Properties Database

2306: 2215: 2181: 2082: 2052: 2016: 1894: 1885: 1743: 1721: 1358: 887:

at any point around these two charges is found by calculating the

410: 373: 372: 262: 83: 1954:. The reduction of convection provides the thermal insulation of 3492: 2718: 2399: 2247: 1982:, and process purging. The electrical properties of vacuum make 1765: 1761: 1542: 1302:

that hop into and out of existence), and a finite energy called

482: 303: 3650:

Introduction to complex mediums for optics and electromagnetics

254:

argued for the existence of vacuum in the first century BC and

174:

times, but was not studied empirically until the 17th century.

4882:

Discussion of the effects on humans of exposure to hard vacuum

4086:"§ 19.1.9 Vacuum polarization in quantum electrodynamics" 3381: 3225:"What words in the English language contain two u's in a row?" 2425:, can survive vacuum conditions for periods of days or weeks. 1416: 678: 563: 246:

debated the existence of a vacuum, or void, in the context of

136:

is used to describe an object that is surrounded by a vacuum.

122:

to refer to an actual imperfect vacuum as one might have in a

4768:

University of New Hampshire Experimental Space Plasma Group.

4119:

Elementary Particles: Volume 21/A of Landolt-Börnstein series

3785:

John F. Donoghue; Eugene Golowich; Barry R. Holstein (1994).

2930:– natural process of solidifying homogeneous "dust" in vacuum 1407:

10 psi) at 100 kilometres (62 mi) of altitude, the

868:

Electromagnetic radiation travels, when unobstructed, at the

3214:

monthly, February 1919, Unnumbered page. Bonnier Corporation

387:

produced one of the first sustained vacuums in a laboratory.

3318:"Arabic and Islamic Natural Philosophy and Natural Science" 2022:

the water column weight balancing the atmospheric pressure.

1753: 1450:. Most artificial satellites operate in this region called 1341:

is believed to have a huge number of vacua – the so-called

4665:"Tardigrades survive exposure to space in low Earth orbit" 3078:"Thousandfold improvement in the measured antiproton mass" 4538:

Survival in Space: Medical Problems of Manned Spaceflight

2919:– vacuum state of semi-classical pure-Yang Mills theories 2370:

this altitude, oxygen enrichment is necessary to prevent

1554:

turns when the MFP is larger than the size of the vanes.

230: 4317:. Edmonton Power Historical Foundation. 22 November 2013 3675:"Electromagnetic Fields in Linear Bianisotropic Mediums" 3412:

A History of Engineering in Classical and Medieval Times

2390:

can still occur if decompression rates are not managed.

801:(technically, these phenomena are the components of the 512:

and of radiant heat. 19th century experiments into this

354:, helped to segregate natural and theological concerns. 2285:

10 torrs (13 pPa). However, pressures as low as 5

2035:, which has an even wider variety of applications. The 1359: 837:, a terminology intended to separate this concept from 4860: 3376:, "Mechanical Engineering in the Medieval Near East", 3260:. New York: Perseus Book Publishing (published 1999). 2224:, a momentum transfer pump used to achieve high vacuum 4336:

Robert M. Besançon, ed. (1990). "Vacuum Techniques".

3771:. Vol. 2. Oxford University Press. p. 389. 3702:

Gilbert Grynberg; Alain Aspect; Claude Fabre (2010).

3648:. In Werner S. Weiglhofer; Akhlesh Lakhtakia (eds.). 3646:"§ 4.1 The classical vacuum as reference medium" 2112:

is an important aspect of the efficient operation of

1477:, and quite likely a correspondingly large number of 1054: 972: 114:

vacuum, which they sometimes simply call "vacuum" or

2170:

to shut down residual outgassing and simultaneously

1371:

awash with charged particles, free elements such as

785:, a vanishing stress–energy tensor implies, through 214: 'an empty space, void', noun use of neuter of 147:

means higher-quality vacuum. For example, a typical

3916:. Vol. 1. New Age International. p. 577. 3805:R. Keith Ellis; W.J. Stirling; B.R. Webber (2003). 3765:Kurt Gottfried; Victor Frederick Weisskopf (1986). 3442:(1st American ed.). New York: Pantheon Books. 2890:– technical instrumentation to detect a vacuum leak 2568:

1.155 kPa to 0.03 kPa (mean 0.6 kPa)

446:'s experiments both demonstrated a partial vacuum. 4876:FAQ on explosive decompression and vacuum exposure 4535: 4115:"Chapter 2: Gauge theories and the Standard Model" 3435: 1893:contain a partial vacuum, usually backfilled with 1128: 1039: 540:, and successfully predicted the existence of the 4845:Leybold – Fundamentals of Vacuum Technology (PDF) 3605:Monthly Notices of the Royal Astronomical Society 3131:Publications of the Astronomical Society of Japan 42:"Free space" redirects here. For other uses, see 4056:Craig, D.P. & Thirunamachandran, T. (1998). 2571:8.66 to 0.23 torrs (0.01139 to 0.00030 atm) 2105:uses electromagnetic induction within a vacuum. 1322:in vacuum near an electric charge are modified. 465:improved Guericke's design and with the help of 4026:Mackay, Tom G & Lakhtakia, Akhlesh (2008). 3477:. Vintage Series. Vintage. pp. 71–72, 77. 3181:Jörg Hüttner & Martin Walter (Ed.) (2022). 2329:Humans and animals exposed to vacuum will lose 2150:. All materials, solid or liquid, have a small 90:. The word is derived from the Latin adjective 4926:The Structured Vacuum – thinking about nothing 3910:Chattopadhyay, D. & Rakshit, P.C. (2004). 3811:. Cambridge University Press. pp. 27–29. 2085:. Obsolete applications include vacuum-driven 4209:Journal of the British Interplanetary Society 1760:(symbol Pa), but vacuum is often measured in 793:. Vacuum does not mean that the curvature of 789:, the vanishing of all the components of the 8: 4856:The Foundations of Vacuum Coating Technology 4200:Andrews, Dana G.; Zubrin, Robert M. (1990). 1930:contamination. This is the principle behind 872:, the defined value 299,792,458 m/s in 4774:The Interstellar Medium, an online tutorial 4733:Öpik, E.J. (1962). "The lunar atmosphere". 3708:. Cambridge University Press. p. 341. 3071: 3069: 2321:, 1768, depicts an experiment performed by 2081:, used to provide power assistance for the 97: 91: 4888:Roberts, Mark D. (2000). "Vacuum Energy". 4871:Journal of Vacuum Science and Technology B 4866:Journal of Vacuum Science and Technology A 4529: 4527: 4525: 4523: 4521: 4202:"Magnetic Sails & Interstellar Travel" 3849:. Princeton University Press. p. 26. 3791:. Cambridge University Press. p. 47. 3124: 3122: 2978: 2976: 2974: 2972: 2970: 1942:which are essential to the fabrication of 1527:do not apply. This vacuum state is called 4897: 4688: 4601: 3625: 3426: 3424: 3207:How to Make an Experimental Geissler Tube 1367:- is not a perfect vacuum, but a tenuous 1125: 1108: 1100: 1092: 1083: 1063: 1055: 1053: 1036: 1019: 1011: 1005: 981: 973: 971: 769:Learn how and when to remove this message 654:Learn how and when to remove this message 4650:unpublished review by Landis, Geoffrey A 4363:Journal of Vacuum Science and Technology 2438: 1962:of liquids and promotes low temperature 1748:A glass McLeod gauge, drained of mercury 1560: 1227: 49: 4799:Nothingness: The Science Of Empty Space 4034:. Vol. 51. Elsevier. p. 143. 3681:. Vol. 51. Elsevier. p. 143. 3639: 3637: 3258:Nothingness: The Science of Empty Space 3171:, for roughly 40 atoms per cubic meter. 2966: 2314:An Experiment on a Bird in the Air Pump 2254:impact. Collectively, these are called 2093:fuel pumps. Some aircraft instruments ( 1275:' to distinguish it from the vacuum of 1109: 1101: 1064: 1056: 1020: 1012: 982: 974: 357:Almost two thousand years after Plato, 3251: 3249: 1245:spontaneous parametric down-conversion 4721:"1976 Standard Atmosphere Properties" 4260:. Boulder, Colorado: Westview Press. 3996:"Characteristic impedance of vacuum, 3059:Note that 1 inch of water is ≈0.0025 2374:in humans that did not undergo prior 2031:Vacuums are commonly used to produce 1732:not normally be considered a vacuum. 1398:Stars, planets, and moons keep their 7: 4619:Life Support & Biosphere Science 4430:(Second ed.). NASA. p. 5. 4403:. geoffreylandis.com. Archived from 3739:. Little, Brown and Co. pp. 60 2077:. The best known application is the 1998:are used in electrical switchgear. 1712:Relative versus absolute measurement 707:adding citations to reliable sources 592:adding citations to reliable sources 286:, the physicist and Islamic scholar 166:Vacuum has been a frequent topic of 4852:by Canadian astrophysicist Doctor P 4176:"Catalog of Earth Satellite Orbits" 3323:Stanford Encyclopedia of Philosophy 3296:Stanford Encyclopedia of Philosophy 3147:This source estimates a density of 1810:gauges (such as the mercury column 1740:Measurements relative to 1 atm 1458:, a proposed propulsion system for 71: 4823:. Johns Hopkins University Press. 4145:Squire, Tom (September 27, 2000). 2607:0.1 to 0.01 torrs (0.000132 to 1.3 1788:. Low vacuum is often measured in 1485:of this radiation is about 3 902:are exactly the electric constant 25: 4770:"What is the Interstellar Medium" 4503:Koestler, A. G. (November 1965). 4059:Molecular Quantum Electrodynamics 2907:– reduction of a medium's density 1239:A video of an experiment showing 4723:calculator. Retrieved 2012-01-28 4147:"U.S. Standard Atmosphere, 1976" 2178:Pumping and ambient air pressure 1469:is filled with large numbers of 1435:. Astrophysicists prefer to use 861:that are not identically unity. 683: 568: 3652:. SPIE Press. pp. 28, 34. 3534:"The World's Largest Barometer" 2333:after a few seconds and die of 1853:Resistance Temperature Detector 1716:Vacuum is measured in units of 1668:standard or reference pressures 1337:gives rise to a single vacuum. 1271:this vacuum is referred to as ' 1243:(in the red ring) amplified by 694:needs additional citations for 579:needs additional citations for 306:was described by Arab engineer 3788:Dynamics of the standard model 3512:. Cambridge University Press. 2913:– creation of a partial vacuum 2444:Pressure (Pa if not explained) 1122: 1105: 1077: 1060: 1033: 1016: 995: 978: 492:. Borrowing somewhat from the 218:, meaning "empty", related to 1: 4850:VIDEO on the nature of vacuum 4644:Czarnik, Tamarack R. (1999). 4258:Building Scientific Apparatus 3846:Nuclear physics in a nutshell 3644:Werner S. Weiglhofer (2003). 3320:, in Zalta, Edward N. (ed.), 3293:, in Zalta, Edward N. (ed.), 3289:Druart, Therese-Anne (2016), 2338:internal body temperature of 2293:Effects on humans and animals 2059:, they have been replaced by 544:, confirmed two years later. 419:, used to discover and study 27:Space that is empty of matter 4932:and Berndt Muller (1985) 4890:High Energy Physics – Theory 4755:10.1016/0032-0633(62)90149-6 4534:Harding, Richard M. (1989). 3843:Carlos A. Bertulani (2007). 3768:Concepts of particle physics 3586:Essays in History and Art 10 2108:Maintaining a vacuum in the 1776:scale or as a percentage of 4915:Vacuum, Production of Space 4735:Planetary and Space Science 4338:The Encyclopedia of Physics 3879:"Speed of light in vacuum, 3344:Dallal, Ahmad (2001–2002). 3105:10.1103/PhysRevLett.65.1317 2211:positive displacement pumps 1703:, and other aspects of the 1475:cosmic background radiation 44:Free space (disambiguation) 4990: 4574:Advances in Space Research 4401:"Human Exposure to Vacuum" 4315:"Kenotometer Vacuum Gauge" 4121:. Springer. pp. 2–3. 4084:Zeidler, Eberhard (2011). 3229:Oxford Dictionaries Online 3020:. McGraw-Hill. p. 3. 2549:approximately 3.2 kPa 2432: 2303:Uncontrolled decompression 2296: 2190: 2132: 1652:extreme-high vacuum (XHV) 1504: 1352: 1213: 1202:is a spatial location and 819:classical electromagnetism 423:, was an evolution of the 408:when the port was sealed. 367:namesake coordinate system 29: 4690:10.1016/j.cub.2008.06.048 4594:10.1016/j.asr.2010.12.017 4428:Bioastronautics Data Book 4180:earthobservatory.nasa.gov 4113:Altarelli, Guido (2008). 4092:. Springer. p. 952. 4028:"§ 3.1.1 Free space" 3733:Leonard Susskind (2006). 3016:Harris, Nigel S. (1989). 2987:. Boca Raton: CRC Press. 2983:Chambers, Austin (2004). 2552:24 torrs (0.032 atm) 2469:760 torrs (1.00 atm) 2055:in the UK but, except on 2051:were once widely used on 1958:. Deep vacuum lowers the 1936:physical vapor deposition 1932:chemical vapor deposition 1569: 1566: 1563: 457:and conducted his famous 222:, meaning "to be empty". 3808:QCD and collider physics 3598:Pickering, W.H. (1912). 3582:Robert Hogarth Patterson 2888:Helium mass spectrometer 2676:1 cm to 100 km 2591:100 μm to 1 mm 2146:into a vacuum is called 2103:Vacuum induction melting 1756:unit of pressure is the 1633:ultra-high vacuum (UHV) 937:characteristic impedance 787:Einstein field equations 560:Classical field theories 508:'s explanations of both 238:Historical understanding 188:incandescent light bulbs 4974:Latin words and phrases 4861:American Vacuum Society 4747:1962P&SS....9..211O 4291:Mechanical Measurements 3380:, May 1991, pp. 64–69 ( 3085:Physical Review Letters 3041:Campbell, Jeff (2005). 2600:Incandescent light bulb 2545:liquid ring vacuum pump 2231:Momentum transfer pumps 2122:liquid ring vacuum pump 2095:Attitude Indicator (AI) 2041:Isambard Kingdom Brunel 2008:flywheel energy storage 1907:incandescent light bulb 1343:string theory landscape 1269:quantum electrodynamics 945:impedance of free space 881:superposition principle 37:Vacuum (disambiguation) 4030:. In Emil Wolf (ed.). 3677:. In Emil Wolf (ed.). 3673:Tom G. MacKay (2008). 3627:10.1093/mnras/72.9.740 3506:Grant, Edward (1981). 3389:Mechanical Engineering 3326:(Spring 2022 ed.) 3316:McGinnis, Jon (2022), 3299:(Winter 2021 ed.) 3256:Genz, Henning (1994). 3047:. Rodale. p. 97. 3018:Modern Vacuum Practice 2614:1 mm to 1 cm 2528:Condenser backpressure 2384:decompression sickness 2326: 2319:Joseph Wright of Derby 2225: 2188: 2099:Heading Indicator (HI) 2027:Vacuum-driven machines 2023: 1902: 1790:millimeters of mercury 1749: 1589:medium (fine) vacuum 1388: 1385:electromagnetic fields 1327:cosmological inflation 1277:quantum chromodynamics 1248: 1130: 1041: 961:constitutive relations 913:and magnetic constant 849:can produce transient 433:Evangelista Torricelli 428: 388: 180:Evangelista Torricelli 98: 92: 63: 35:. For other uses, see 4796:Henning Genz (2001). 4542:. London: Routledge. 3967:"Magnetic constant, μ 3938:"Electric constant, ε 3783:and more recently in 3471:Barrow, J.D. (2002). 3408:Donald Routledge Hill 3385:Donald Routledge Hill 3374:Donald Routledge Hill 3350:University of Chicago 2985:Modern Vacuum Physics 2779:10 to 100,000 km 2649:1 cm to 1 m 2310: 2219: 2185: 2069:can be used to drive 2037:Newcomen steam engine 2020: 1911:electron beam welding 1897:, which protects the 1889: 1839:capacitance manometer 1800:Measuring instruments 1747: 1586:<100 Pa to 0.1 Pa 1460:interplanetary travel 1362: 1333:of the energy in the 1238: 1214:Further information: 1141:electric displacement 1131: 1042: 859:relative permeability 855:relative permittivity 550:uncertainty principle 459:Magdeburg hemispheres 414: 376: 170:debate since ancient 53: 4964:Industrial processes 4817:Luciano Boi (2011). 2807:Interplanetary space 2509:approximately 80 kPa 2492:approx. 87 to 95 kPa 2447:Pressure (Torr, atm) 2220:A cutaway view of a 1990:possible, including 1984:electron microscopes 1845:Thermal conductivity 1778:atmospheric pressure 1664:Atmospheric pressure 1578:low (rough) vacuum 1507:Pressure measurement 1308:spontaneous emission 1257:quantum field theory 1052: 970: 928:), or exactly 1 (in 825:, or sometimes just 823:vacuum of free space 703:improve this article 668:stress–energy tensor 588:improve this article 297:Abū Rayhān al-Bīrūnī 108:atmospheric pressure 4908:2000hep.th...12062R 4681:2008CBio...18.R729J 4586:2011AdSpR..47.1600W 4375:1989JVSTA...7.2439I 4369:(3–II): 2439–2442. 4157:on October 15, 2011 3913:Elements of Physics 3855:2007npn..book.....B 3618:1912MNRAS..72..740P 3418:, pp. 143, 150–152. 3378:Scientific American 3143:1968PASJ...20..230T 3097:1990PhRvL..65.1317G 2868:Decay of the vacuum 2843:Intergalactic space 2461:Standard atmosphere 2222:turbomolecular pump 2045:atmospheric railway 1996:Vacuum interrupters 1796:than) 1 torr. 1467:observable universe 1335:configuration space 1296:vacuum fluctuations 1241:vacuum fluctuations 924:, respectively (in 847:vacuum fluctuations 799:gravitational waves 514:luminiferous aether 453:invented the first 393:thought experiments 337:Paris condemnations 118:, and use the term 4959:Physical phenomena 4892:: hep–th/0012062. 4478:Aerospace Medicine 4451:Aerospace Medicine 4032:Progress in Optics 3679:Progress in Optics 3563:www.britannica.com 3394:2007-12-25 at the 2946:Vacuum engineering 2825:Interstellar space 2709:1 to 1,000 km 2327: 2226: 2189: 2024: 1903: 1750: 1552:Crookes radiometer 1535:, but at 100 1413:radiation pressure 1389: 1320:electric potential 1249: 1180:magnetic induction 1126: 1037: 783:general relativity 502:Aether (mythology) 429: 389: 256:Hero of Alexandria 244:Greek philosophers 64: 4924:Free pdf copy of 4830:978-1-4214-0247-5 4809:978-0-7382-0610-3 4802:. Da Capo Press. 4675:(17): R729–R731. 4652:. geoffreylandis. 4549:978-0-415-00253-0 4484:(11): 1148–1152. 4399:(7 August 2007). 4347:978-0-442-00522-1 4300:978-0-201-56947-6 4267:978-0-8133-4007-4 4128:978-3-540-74202-9 4099:978-3-642-22420-1 4069:978-0-486-40214-7 4054:For example, see 4041:978-0-444-53211-4 3923:978-81-224-1538-4 3864:978-0-691-12505-3 3818:978-0-521-54589-1 3798:978-0-521-47652-2 3778:978-0-19-503393-9 3750:978-0-316-01333-8 3715:978-0-521-55112-0 3688:978-0-444-52038-8 3659:978-0-8194-4947-4 3519:978-0-521-22983-8 3484:978-0-375-72609-5 3449:978-0-09-928845-9 3267:978-0-7382-0610-3 3235:on August 8, 2018 3192:978-3-487-16076-4 3091:(11): 1317–1320. 3054:978-1-59486-274-8 3027:978-0-07-707099-1 2994:978-0-8493-2438-3 2940:Vacuum deposition 2858: 2857: 2463:, for comparison 2455:Molecules per cm 2372:altitude sickness 2263:ultra high vacuum 2160:rotary vane pumps 2087:windscreen wipers 2057:heritage railways 1992:cathode ray tubes 1966:which is used in 1927:Ultra-high vacuum 1865:Ionization gauges 1701:virtual particles 1660: 1659: 1607:high vacuum (HV) 1513:absolute pressure 1363:Structure of the 1300:virtual particles 1289:blackbody photons 1253:quantum mechanics 1236: 1210:Quantum mechanics 1118: 1098: 1073: 1029: 991: 779: 778: 771: 753: 664: 663: 656: 638: 546:Werner Heisenberg 479:Heinrich Geissler 477:and in 1855 when 451:Otto von Guericke 196:human spaceflight 157:Ultra-high vacuum 16:(Redirected from 4981: 4911: 4901: 4834: 4813: 4789: 4788: 4786: 4785: 4776:. Archived from 4765: 4759: 4758: 4730: 4724: 4717: 4711: 4710: 4692: 4660: 4654: 4653: 4641: 4635: 4634: 4614: 4608: 4607: 4605: 4603:2060/20130009997 4580:(9): 1600–1607. 4569: 4563: 4561: 4541: 4531: 4516: 4515: 4509: 4500: 4494: 4493: 4473: 4467: 4466: 4446: 4440: 4439: 4436:2060/19730006364 4423: 4417: 4416: 4414: 4412: 4397:Landis, Geoffrey 4393: 4387: 4386: 4383:10.1116/1.575916 4358: 4352: 4351: 4333: 4327: 4326: 4324: 4322: 4311: 4305: 4304: 4286: 4280: 4279: 4253: 4247: 4246: 4244: 4243: 4237: 4231:. Archived from 4206: 4197: 4191: 4190: 4188: 4187: 4172: 4166: 4165: 4163: 4162: 4153:. Archived from 4142: 4136: 4135: 4110: 4104: 4103: 4080: 4074: 4073: 4052: 4046: 4045: 4023: 4017: 4016: 4014: 4013: 3992: 3986: 3985: 3983: 3982: 3963: 3957: 3956: 3954: 3953: 3934: 3928: 3927: 3907: 3901: 3900: 3898: 3897: 3875: 3869: 3868: 3825: 3802: 3782: 3761: 3755: 3754: 3729: 3723: 3722: 3699: 3693: 3692: 3670: 3664: 3663: 3641: 3632: 3631: 3629: 3595: 3589: 3579: 3573: 3572: 3570: 3569: 3555: 3549: 3548: 3546: 3545: 3536:. Archived from 3530: 3524: 3523: 3503: 3497: 3496: 3468: 3462: 3461: 3441: 3428: 3419: 3405: 3399: 3371: 3365: 3364: 3362: 3361: 3352:. Archived from 3341: 3335: 3333: 3332: 3331: 3313: 3307: 3306: 3305: 3304: 3286: 3280: 3279: 3253: 3244: 3243: 3241: 3240: 3231:. Archived from 3221: 3215: 3203: 3197: 3196: 3178: 3172: 3170: 3168: 3161:atomic mass unit 3154: 3152: 3146: 3126: 3117: 3116: 3082: 3073: 3064: 3058: 3038: 3032: 3031: 3013: 3007: 3006: 2980: 2928:Vacuum cementing 2773: 2771: 2765: 2763: 2745: 2743: 2730: 2728: 2717:Pressure on the 2703: 2701: 2695: 2693: 2670: 2668: 2645: 2641: 2637: 2633: 2610: 2481: 2479: 2439: 2341: 2288: 2284: 2256:vacuum technique 2235:Entrapment pumps 2203:diaphragm muscle 2043:'s experimental 2012:ultracentrifuges 1948:optical coatings 1649: 1647: 1630: 1628: 1622: 1620: 1604: 1602: 1561: 1545: 1473:, the so-called 1421:dynamic pressure 1406: 1331:stationary point 1237: 1205: 1201: 1193: 1177: 1161: 1150: 1135: 1133: 1132: 1127: 1116: 1112: 1104: 1099: 1097: 1096: 1084: 1071: 1067: 1059: 1046: 1044: 1043: 1038: 1027: 1023: 1015: 1010: 1009: 989: 985: 977: 955:≈ 376.73 Ω. 954: 942: 922: 911: 853:densities and a 851:virtual particle 835:classical vacuum 813:Electromagnetism 774: 767: 763: 760: 754: 752: 711: 692:This subsection 687: 679: 659: 652: 648: 645: 639: 637: 596: 577:This subsection 572: 564: 528:Later, in 1930, 323:Blasius of Parma 282:In the medieval 151:produces enough 101: 95: 73: 54:Vacuum pump and 47: 40: 21: 4989: 4988: 4984: 4983: 4982: 4980: 4979: 4978: 4944: 4943: 4930:Johann Rafelski 4887: 4841: 4831: 4816: 4810: 4795: 4792: 4783: 4781: 4767: 4766: 4762: 4732: 4731: 4727: 4719:Computed using 4718: 4714: 4669:Current Biology 4662: 4661: 4657: 4643: 4642: 4638: 4616: 4615: 4611: 4571: 4570: 4566: 4550: 4533: 4532: 4519: 4507: 4502: 4501: 4497: 4475: 4474: 4470: 4448: 4447: 4443: 4438:. NASA SP-3006. 4425: 4424: 4420: 4410: 4408: 4407:on 21 July 2009 4395: 4394: 4390: 4360: 4359: 4355: 4348: 4335: 4334: 4330: 4320: 4318: 4313: 4312: 4308: 4301: 4288: 4287: 4283: 4268: 4255: 4254: 4250: 4241: 4239: 4235: 4221:10.2514/3.26230 4204: 4199: 4198: 4194: 4185: 4183: 4174: 4173: 4169: 4160: 4158: 4144: 4143: 4139: 4129: 4112: 4111: 4107: 4100: 4083: 4081: 4077: 4070: 4055: 4053: 4049: 4042: 4025: 4024: 4020: 4011: 4009: 4002: 3994: 3993: 3989: 3980: 3978: 3970: 3965: 3964: 3960: 3951: 3949: 3941: 3936: 3935: 3931: 3924: 3909: 3908: 3904: 3895: 3893: 3885: 3877: 3876: 3872: 3865: 3842: 3819: 3804: 3799: 3784: 3779: 3764: 3762: 3758: 3751: 3732: 3730: 3726: 3716: 3701: 3700: 3696: 3689: 3672: 3671: 3667: 3660: 3643: 3642: 3635: 3597: 3596: 3592: 3580: 3576: 3567: 3565: 3557: 3556: 3552: 3543: 3541: 3532: 3531: 3527: 3520: 3505: 3504: 3500: 3485: 3470: 3469: 3465: 3450: 3432:Barrow, John D. 3430: 3429: 3422: 3406: 3402: 3396:Wayback Machine 3372: 3368: 3359: 3357: 3343: 3342: 3338: 3329: 3327: 3315: 3314: 3310: 3302: 3300: 3288: 3287: 3283: 3268: 3255: 3254: 3247: 3238: 3236: 3223: 3222: 3218: 3212:Popular Science 3204: 3200: 3193: 3180: 3179: 3175: 3166: 3164: 3150: 3148: 3128: 3127: 3120: 3080: 3075: 3074: 3067: 3055: 3040: 3039: 3035: 3028: 3015: 3014: 3010: 2995: 2982: 2981: 2968: 2964: 2959: 2872:Pair production 2863: 2769: 2767: 2761: 2759: 2741: 2739: 2726: 2724: 2699: 2697: 2691: 2689: 2666: 2664: 2643: 2639: 2638:10 torrs (1.316 2635: 2631: 2608: 2564:Mars atmosphere 2477: 2475: 2437: 2431: 2376:acclimatization 2339: 2311:This painting, 2305: 2295: 2286: 2282: 2195: 2180: 2168:liquid nitrogen 2152:vapour pressure 2137: 2131: 2067:Manifold vacuum 2029: 1956:thermos bottles 1952:surface science 1884: 1802: 1742: 1714: 1645: 1643: 1626: 1624: 1618: 1616: 1600: 1598: 1564:Pressure range 1540: 1525:fluid mechanics 1509: 1503: 1493:; −454.27 1452:low Earth orbit 1404: 1357: 1351: 1228: 1226: 1212: 1203: 1195: 1187: 1171: 1155: 1144: 1088: 1050: 1049: 1001: 968: 967: 953: 947: 940: 921: 915: 910: 904: 815: 775: 764: 758: 755: 712: 710: 700: 688: 677: 660: 649: 643: 640: 597: 595: 585: 573: 562: 522:Henry Pickering 344:Étienne Tempier 240: 210:comes from 204: 176:Clemens Timpler 106:much less than 48: 41: 30: 28: 23: 22: 15: 12: 11: 5: 4987: 4985: 4977: 4976: 4971: 4966: 4961: 4956: 4946: 4945: 4942: 4941: 4922: 4917: 4912: 4899:hep-th/0012062 4885: 4879: 4873: 4868: 4863: 4858: 4853: 4847: 4840: 4839:External links 4837: 4836: 4835: 4829: 4814: 4808: 4791: 4790: 4760: 4741:(5): 211–244. 4725: 4712: 4655: 4636: 4609: 4564: 4548: 4517: 4495: 4468: 4457:(4): 376–383. 4441: 4418: 4388: 4353: 4346: 4328: 4306: 4299: 4281: 4266: 4248: 4192: 4167: 4137: 4127: 4105: 4098: 4075: 4068: 4047: 4040: 4018: 4000: 3987: 3968: 3958: 3939: 3929: 3922: 3902: 3883: 3870: 3863: 3817: 3797: 3777: 3756: 3749: 3724: 3714: 3694: 3687: 3665: 3658: 3633: 3590: 3574: 3550: 3525: 3518: 3498: 3483: 3463: 3448: 3420: 3400: 3366: 3336: 3308: 3281: 3266: 3245: 3216: 3198: 3191: 3173: 3118: 3065: 3053: 3044:Speed cleaning 3033: 3026: 3008: 2993: 2965: 2963: 2960: 2958: 2957: 2955:vacuum systems 2948: 2943: 2937: 2931: 2925: 2920: 2914: 2908: 2902: 2899:Pneumatic tube 2896: 2894:Vacuum brazing 2891: 2885: 2880: 2875: 2864: 2862: 2859: 2856: 2855: 2852: 2850: 2848: 2845: 2839: 2838: 2835: 2833: 2830: 2827: 2821: 2820: 2817: 2815: 2812: 2809: 2803: 2802: 2799: 2797: 2794: 2791: 2784: 2783: 2780: 2777: 2774: 2757: 2747: 2746: 2737: 2736:10,000 km 2734: 2731: 2723:approximately 2721: 2714: 2713: 2710: 2707: 2704: 2687: 2681: 2680: 2677: 2674: 2671: 2661: 2654: 2653: 2650: 2647: 2628: 2625: 2623:Thermos bottle 2619: 2618: 2615: 2612: 2605: 2602: 2596: 2595: 2592: 2589: 2586: 2583: 2577: 2576: 2574: 2572: 2569: 2566: 2560: 2559: 2556: 2553: 2550: 2547: 2541: 2540: 2538: 2536: 2534: 2531: 2520: 2519: 2516: 2513: 2510: 2507: 2505:Vacuum cleaner 2501: 2500: 2498: 2496: 2493: 2490: 2483: 2482: 2473: 2470: 2467: 2464: 2457: 2456: 2453: 2451:Mean free path 2448: 2445: 2442: 2430: 2427: 2419:microorganisms 2299:Space exposure 2294: 2291: 2191:Main article: 2179: 2176: 2133:Main article: 2130: 2127: 2116:. A steam jet 2114:steam turbines 2028: 2025: 2006:is useful for 1944:semiconductors 1919:vacuum packing 1883: 1880: 1801: 1798: 1741: 1738: 1713: 1710: 1709: 1708: 1705:quantum vacuum 1681:Perfect vacuum 1678: 1671: 1658: 1657: 1653: 1650: 1639: 1638: 1634: 1631: 1612: 1611: 1608: 1605: 1597:<0.1 Pa to 1594: 1593: 1590: 1587: 1583: 1582: 1579: 1576: 1572: 1571: 1568: 1565: 1521:mean free path 1505:Main article: 1502: 1499: 1489:(−270.15 1481:. The current 1437:number density 1353:Main article: 1350: 1347: 1211: 1208: 1164:magnetic field 1153:electric field 1137: 1136: 1124: 1121: 1115: 1111: 1107: 1103: 1095: 1091: 1087: 1082: 1079: 1076: 1070: 1066: 1062: 1058: 1047: 1035: 1032: 1026: 1022: 1018: 1014: 1008: 1004: 1000: 997: 994: 988: 984: 980: 976: 957: 956: 951: 933: 930:Gaussian units 919: 908: 892: 885:electric field 877: 870:speed of light 831:perfect vacuum 814: 811: 777: 776: 691: 689: 682: 676: 673: 662: 661: 576: 574: 567: 561: 558: 538:Dirac equation 471:August Toepler 359:René Descartes 239: 236: 203: 200: 149:vacuum cleaner 120:partial vacuum 33:vacuum cleaner 26: 24: 18:Perfect vacuum 14: 13: 10: 9: 6: 4: 3: 2: 4986: 4975: 4972: 4970: 4967: 4965: 4962: 4960: 4957: 4955: 4952: 4951: 4949: 4939: 4938:3-87144-889-3 4935: 4931: 4927: 4923: 4921: 4918: 4916: 4913: 4909: 4905: 4900: 4895: 4891: 4886: 4883: 4880: 4877: 4874: 4872: 4869: 4867: 4864: 4862: 4859: 4857: 4854: 4851: 4848: 4846: 4843: 4842: 4838: 4832: 4826: 4822: 4821: 4815: 4811: 4805: 4801: 4800: 4794: 4793: 4780:on 2006-02-17 4779: 4775: 4771: 4764: 4761: 4756: 4752: 4748: 4744: 4740: 4736: 4729: 4726: 4722: 4716: 4713: 4708: 4704: 4700: 4696: 4691: 4686: 4682: 4678: 4674: 4670: 4666: 4659: 4656: 4651: 4647: 4640: 4637: 4632: 4628: 4625:(2): 93–101. 4624: 4620: 4613: 4610: 4604: 4599: 4595: 4591: 4587: 4583: 4579: 4575: 4568: 4565: 4559: 4555: 4551: 4545: 4540: 4539: 4530: 4528: 4526: 4524: 4522: 4518: 4513: 4506: 4499: 4496: 4491: 4487: 4483: 4479: 4472: 4469: 4464: 4460: 4456: 4452: 4445: 4442: 4437: 4433: 4429: 4422: 4419: 4406: 4402: 4398: 4392: 4389: 4384: 4380: 4376: 4372: 4368: 4364: 4357: 4354: 4349: 4343: 4339: 4332: 4329: 4316: 4310: 4307: 4302: 4296: 4292: 4285: 4282: 4277: 4273: 4269: 4263: 4259: 4252: 4249: 4238:on 2019-03-02 4234: 4230: 4226: 4222: 4218: 4214: 4210: 4203: 4196: 4193: 4181: 4177: 4171: 4168: 4156: 4152: 4148: 4141: 4138: 4134: 4130: 4124: 4120: 4116: 4109: 4106: 4101: 4095: 4091: 4087: 4079: 4076: 4071: 4065: 4061: 4060: 4051: 4048: 4043: 4037: 4033: 4029: 4022: 4019: 4008: 4004: 3999: 3991: 3988: 3976: 3972: 3962: 3959: 3947: 3943: 3933: 3930: 3925: 3919: 3915: 3914: 3906: 3903: 3891: 3887: 3882: 3874: 3871: 3866: 3860: 3856: 3852: 3848: 3847: 3840: 3836: 3832: 3828: 3824: 3820: 3814: 3810: 3809: 3800: 3794: 3790: 3789: 3780: 3774: 3770: 3769: 3760: 3757: 3752: 3746: 3742: 3738: 3737: 3728: 3725: 3721: 3717: 3711: 3707: 3706: 3698: 3695: 3690: 3684: 3680: 3676: 3669: 3666: 3661: 3655: 3651: 3647: 3640: 3638: 3634: 3628: 3623: 3619: 3615: 3611: 3607: 3606: 3601: 3594: 3591: 3587: 3583: 3578: 3575: 3564: 3560: 3554: 3551: 3540:on 2008-04-17 3539: 3535: 3529: 3526: 3521: 3515: 3511: 3510: 3502: 3499: 3494: 3490: 3486: 3480: 3476: 3475: 3467: 3464: 3459: 3455: 3451: 3445: 3440: 3439: 3433: 3427: 3425: 3421: 3417: 3413: 3409: 3404: 3401: 3397: 3393: 3390: 3386: 3383: 3379: 3375: 3370: 3367: 3356:on 2012-02-10 3355: 3351: 3347: 3340: 3337: 3325: 3324: 3319: 3312: 3309: 3298: 3297: 3292: 3285: 3282: 3277: 3273: 3269: 3263: 3259: 3252: 3250: 3246: 3234: 3230: 3226: 3220: 3217: 3213: 3209: 3208: 3202: 3199: 3194: 3188: 3184: 3177: 3174: 3162: 3158: 3144: 3140: 3136: 3132: 3125: 3123: 3119: 3114: 3110: 3106: 3102: 3098: 3094: 3090: 3086: 3079: 3072: 3070: 3066: 3062: 3056: 3050: 3046: 3045: 3037: 3034: 3029: 3023: 3019: 3012: 3009: 3004: 3000: 2996: 2990: 2986: 2979: 2977: 2975: 2973: 2971: 2967: 2961: 2956: 2953:– joining of 2952: 2951:Vacuum flange 2949: 2947: 2944: 2941: 2938: 2935: 2934:Vacuum column 2932: 2929: 2926: 2924: 2921: 2918: 2915: 2912: 2909: 2906: 2903: 2900: 2897: 2895: 2892: 2889: 2886: 2884: 2881: 2879: 2878:Engine vacuum 2876: 2873: 2869: 2866: 2865: 2860: 2853: 2851: 2849: 2846: 2844: 2841: 2840: 2836: 2834: 2831: 2828: 2826: 2823: 2822: 2818: 2816: 2813: 2810: 2808: 2805: 2804: 2800: 2798: 2795: 2792: 2790: 2786: 2785: 2781: 2778: 2775: 2758: 2755: 2752: 2749: 2748: 2738: 2735: 2732: 2722: 2720: 2716: 2715: 2711: 2708: 2705: 2688: 2686: 2683: 2682: 2678: 2675: 2672: 2663:1 Pa to 2662: 2660: 2656: 2655: 2651: 2648: 2629: 2626: 2624: 2621: 2620: 2616: 2613: 2606: 2603: 2601: 2598: 2597: 2593: 2590: 2587: 2584: 2582: 2581:freeze drying 2579: 2578: 2575: 2573: 2570: 2567: 2565: 2562: 2561: 2557: 2554: 2551: 2548: 2546: 2543: 2542: 2539: 2537: 2535: 2532: 2529: 2525: 2524:Steam turbine 2522: 2521: 2517: 2514: 2511: 2508: 2506: 2503: 2502: 2499: 2497: 2494: 2491: 2489: 2485: 2484: 2474: 2471: 2468: 2465: 2462: 2459: 2458: 2454: 2452: 2449: 2446: 2443: 2441: 2440: 2436: 2428: 2426: 2424: 2420: 2417: 2412: 2410: 2405: 2401: 2397: 2391: 2389: 2388:gas embolisms 2385: 2381: 2377: 2373: 2367: 2364: 2362: 2356: 2353: 2349: 2345: 2336: 2332: 2331:consciousness 2324: 2320: 2316: 2315: 2309: 2304: 2300: 2292: 2290: 2279: 2276: 2272: 2268: 2264: 2259: 2257: 2251: 2249: 2245: 2241: 2236: 2232: 2223: 2218: 2214: 2212: 2207: 2204: 2200: 2194: 2184: 2177: 2175: 2173: 2169: 2163: 2161: 2155: 2153: 2149: 2145: 2141: 2136: 2128: 2126: 2123: 2119: 2115: 2111: 2106: 2104: 2100: 2096: 2092: 2088: 2084: 2080: 2076: 2072: 2068: 2064: 2062: 2058: 2054: 2050: 2049:Vacuum brakes 2046: 2042: 2038: 2034: 2026: 2019: 2015: 2013: 2009: 2005: 2001: 1997: 1993: 1989: 1985: 1981: 1977: 1974:preparation, 1973: 1969: 1968:freeze drying 1965: 1961: 1960:boiling point 1957: 1953: 1949: 1945: 1941: 1937: 1933: 1928: 1924: 1923:vacuum frying 1920: 1916: 1912: 1908: 1900: 1896: 1892: 1888: 1881: 1879: 1876: 1871: 1867: 1866: 1861: 1858: 1854: 1850: 1846: 1842: 1840: 1836: 1832: 1828: 1824: 1821: 1817: 1813: 1809: 1805: 1799: 1797: 1793: 1791: 1787: 1783: 1779: 1775: 1771: 1767: 1763: 1759: 1755: 1746: 1739: 1737: 1733: 1730: 1725: 1723: 1719: 1711: 1706: 1702: 1698: 1695:, as well as 1694: 1690: 1686: 1682: 1679: 1675: 1672: 1669: 1665: 1662: 1661: 1654: 1651: 1641: 1640: 1635: 1632: 1614: 1613: 1609: 1606: 1596: 1595: 1591: 1588: 1585: 1584: 1580: 1577: 1574: 1573: 1562: 1559: 1555: 1553: 1549: 1544: 1538: 1534: 1530: 1526: 1522: 1518: 1514: 1508: 1500: 1498: 1496: 1492: 1488: 1484: 1480: 1476: 1472: 1468: 1463: 1461: 1457: 1453: 1449: 1445: 1440: 1438: 1434: 1433:space weather 1430: 1426: 1422: 1418: 1414: 1410: 1401: 1396: 1393: 1386: 1382: 1378: 1374: 1370: 1366: 1365:magnetosphere 1361: 1356: 1348: 1346: 1344: 1340: 1339:String theory 1336: 1332: 1328: 1323: 1321: 1317: 1316:Coulomb's law 1313: 1309: 1305: 1304:vacuum energy 1301: 1297: 1292: 1290: 1286: 1282: 1279:, denoted as 1278: 1274: 1270: 1266: 1265:Hilbert space 1262: 1258: 1254: 1246: 1242: 1225: 1221: 1217: 1209: 1207: 1200: 1199: 1192: 1191: 1185: 1181: 1176: 1175: 1169: 1165: 1160: 1159: 1154: 1149: 1148: 1142: 1139:relating the 1119: 1113: 1093: 1089: 1085: 1080: 1074: 1068: 1048: 1030: 1024: 1006: 1002: 998: 992: 986: 966: 965: 964: 963:in SI units: 962: 950: 946: 943:) equals the 938: 934: 931: 927: 923: 918: 912: 907: 901: 897: 893: 890: 886: 882: 878: 875: 871: 867: 866: 865: 862: 860: 856: 852: 848: 844: 840: 836: 832: 828: 824: 820: 812: 810: 808: 804: 800: 796: 792: 788: 784: 773: 770: 762: 751: 748: 744: 741: 737: 734: 730: 727: 723: 720: – 719: 715: 714:Find sources: 708: 704: 698: 697: 690: 686: 681: 680: 674: 672: 669: 658: 655: 647: 636: 633: 629: 626: 622: 619: 615: 612: 608: 605: – 604: 600: 599:Find sources: 593: 589: 583: 582: 575: 571: 566: 565: 559: 557: 555: 551: 547: 543: 539: 535: 531: 526: 523: 520: 515: 511: 507: 503: 499: 498:Stoic physics 495: 491: 486: 484: 480: 476: 473:invented the 472: 468: 464: 460: 456: 452: 447: 445: 444:Blaise Pascal 441: 438: 434: 426: 425:Geissler tube 422: 418: 413: 409: 407: 403: 399: 398:Walter Burley 394: 386: 383: 379: 375: 371: 368: 364: 360: 355: 353: 352:Stoic physics 349: 345: 342: 338: 334: 333: 328: 327:Walter Burley 324: 320: 316: 311: 309: 305: 302: 298: 294: 289: 285: 280: 278: 274: 273: 268: 264: 259: 257: 253: 249: 245: 237: 235: 233: 232: 227: 223: 221: 217: 213: 209: 201: 199: 197: 193: 189: 184: 183:(see below). 181: 177: 173: 169: 168:philosophical 164: 162: 158: 154: 150: 146: 142: 137: 135: 134: 129: 125: 121: 117: 113: 109: 105: 100: 94: 89: 85: 81: 77: 69: 61: 57: 52: 45: 38: 34: 19: 4889: 4819: 4798: 4782:. Retrieved 4778:the original 4773: 4763: 4738: 4734: 4728: 4715: 4672: 4668: 4658: 4649: 4639: 4622: 4618: 4612: 4577: 4573: 4567: 4537: 4511: 4498: 4481: 4477: 4471: 4454: 4450: 4444: 4427: 4421: 4409:. Retrieved 4405:the original 4391: 4366: 4362: 4356: 4337: 4331: 4319:. Retrieved 4309: 4290: 4284: 4257: 4251: 4240:. Retrieved 4233:the original 4212: 4208: 4195: 4184:. Retrieved 4182:. 2009-09-04 4179: 4170: 4159:. Retrieved 4155:the original 4150: 4140: 4132: 4118: 4108: 4089: 4078: 4058: 4050: 4031: 4021: 4010:. Retrieved 4006: 3997: 3990: 3979:. Retrieved 3974: 3961: 3950:. Retrieved 3945: 3932: 3912: 3905: 3894:. Retrieved 3889: 3880: 3873: 3845: 3831:paramagnetic 3822: 3807: 3787: 3767: 3759: 3740: 3735: 3727: 3719: 3704: 3697: 3678: 3668: 3649: 3609: 3603: 3593: 3585: 3577: 3566:. Retrieved 3562: 3553: 3542:. Retrieved 3538:the original 3528: 3508: 3501: 3473: 3466: 3437: 3411: 3403: 3377: 3369: 3358:. 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Retrieved 3233:the original 3228: 3219: 3206: 3201: 3182: 3176: 3153:10 g/cm 3134: 3130: 3088: 3084: 3043: 3036: 3017: 3011: 2984: 2917:Theta vacuum 2883:False vacuum 2659:thermosphere 2646:10 atm) 2611:10 atm) 2555:1.75 μm 2416:extremophile 2413: 2392: 2368: 2365: 2361:Robert Boyle 2357: 2328: 2323:Robert Boyle 2312: 2280: 2260: 2255: 2252: 2227: 2208: 2196: 2174:the system. 2164: 2156: 2138: 2107: 2079:vacuum servo 2065: 2030: 1988:vacuum tubes 1976:distillation 1915:cold welding 1904: 1875:cold cathode 1863: 1862: 1857:Pirani gauge 1849:thermocouple 1844: 1843: 1838: 1834: 1830: 1829: 1825: 1820:McLeod gauge 1807: 1806: 1803: 1794: 1751: 1734: 1726: 1715: 1680: 1673: 1663: 1556: 1548:vacuum tubes 1528: 1510: 1464: 1441: 1429:thermosphere 1397: 1390: 1324: 1293: 1261:ground state 1250: 1224:Vacuum state 1197: 1196: 1189: 1188: 1183: 1173: 1172: 1167: 1157: 1156: 1146: 1145: 1138: 958: 948: 916: 905: 900:permeability 896:permittivity 863: 834: 830: 826: 822: 816: 791:Ricci tensor 780: 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