romikgosai/squad_modified huggingface dataset:
Historically, there has been much dispute over whether such a thing as a vacuum can exist. Ancient Greek philosophers debated the existence of a vacuum, or void, in the context of atomism, which posited void and atom as the fundamental explanatory elements of physics. Following Plato, 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. Aristotle 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.

Questions and answers:
['
Q: What did Aristotle believe about a void?
A: no void could occur naturally,', '
Q: What was historically disputed about vacuums?
A: whether such a thing as a vacuum can exist.', '
Q: What did something that was literally nothing at all,According to Plato, mean?
A: cannot rightly be said to exist', '
Q: Aristotle thought what would fill any rarity that might give rise to a void?
A: denser surrounding material continuum']
In his Physics, book IV, Aristotle offered numerous arguments against the void: for example, that motion through a medium which offered no impediment could continue ad infinitum, there being no reason that something would come to rest anywhere in particular. Although Lucretius argued for the existence of vacuum in the first century BC and Hero of Alexandria tried unsuccessfully to create an artificial vacuum in the first century AD, it was European scholars such as Roger Bacon, Blasius of Parma and Walter Burley in the 13th and 14th century who focused considerable attention on these issues. Eventually following Stoic physics in this instance, scholars from the 14th century onward increasingly departed from the Aristotelian perspective in favor of a supernatural void beyond the confines of the cosmos itself, a conclusion widely acknowledged by the 17th century, which helped to segregate natural and theological concerns.

Questions and answers:
["
Q: In what century did believes start to move away from Aristotle's idea regarding a void?
A: 14th century", '
Q: What thought process was used in the beginning belief of the existence of vacuums?
A: Stoic physics', '
Q: Roger Bacon,Walter Burley and Blasius of Parma were from what century?
A: 13th and 14th', '
Q: What belief regarding a cosmic void was accepted by most in the 17th century?
A: a supernatural void beyond the confines of the cosmos itself']
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 alveoli of the lungs. Eardrums 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 barotrauma. A pressure drop of 13 kPa (100 Torr), which produces no symptoms if it is gradual, may be fatal if it occurs suddenly.

Questions and answers:
['
Q: What does Rapid decompression do to the lungs?
A: rupture of the delicate alveoli', '
Q: What causes barotrauma?
A: rapid decompression', '
Q: What amount of pressure drop can kill you if it occurs suddenly?
A: 13 kPa (100 Torr),', '
Q: What does acceleration of oxygen consumption do?
A: hypoxia', '
Q: rapid decompression is more dangerous than what?
A: vacuum exposure']
Almost two thousand years after Plato, René Descartes also proposed a geometrically based alternative theory of atomism, without the problematic nothing–everything dichotomy of void and atom. Although Descartes agreed with the contemporary position, that a vacuum does not occur in nature, the success of his namesake coordinate system 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. With the acquiescence of Cartesian mechanical philosophy to the "brute fact" of action at a distance, and at length, its successful reification by force fields and ever more sophisticated geometric structure, the anachronism of empty space widened until "a seething ferment" of quantum activity in the 20th century filled the vacuum with a virtual pleroma.

Questions and answers:
['
Q: What did Descartes believe about vacuums in nature?
A: that a vacuum does not occur in nature', '
Q: Whose work with metaphysics would come to define the notion of empty space?
A: Descartes', '
Q: What philosophy combined with Descartes to push quantum activity in the 20th century?
A: Cartesian mechanical philosophy']
In 1930, Paul Dirac proposed a model of the vacuum as an infinite sea of particles possessing negative energy, called the Dirac sea. This theory helped refine the predictions of his earlier formulated Dirac equation, and successfully predicted the existence of the positron, confirmed two years later. Werner Heisenberg's uncertainty principle formulated in 1927, predict a fundamental limit within which instantaneous position and momentum, or energy and time can be measured. This has far reaching consequences on the "emptiness" of space between particles. In the late 20th century, so-called virtual particles that arise spontaneously from empty space were confirmed.

Questions and answers:
['
Q: An infinite sea of particles with negative energy  was a model propesed by whom?
A: Paul Dirac', '
Q: What year was the Dirac sea modeled?
A: 1930', '
Q: When werer virtual particles confirmed?
A: late 20th century', '
Q: What year was the uncertainty principle formed?
A: 1927,', "
Q: What theorized that time and energy can be measured?
A: Werner Heisenberg's uncertainty principle"]
In general relativity, a vanishing stress-energy tensor implies, through Einstein field equations, the vanishing of all the components of the Ricci tensor. Vacuum does not mean that the curvature of space-time is necessarily flat: the gravitational field can still produce curvature in a vacuum in the form of tidal forces and gravitational waves (technically, these phenomena are the components of the Weyl tensor). The black hole (with zero electric charge) is an elegant example of a region completely "filled" with vacuum, but still showing a strong curvature.

Questions and answers:
['
Q: what is a perfect example of a filled vacuum showing a curvature?
A: The black hole', "
Q: Who's equations  helped to imply vanishing of the Ricci tensor?
A: Einstein", '
Q: what produces curvature in a vacuum?
A: tidal forces and gravitational waves', '
Q: What has no electric charge?
A: black hole']
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 drag on satellites. Most artificial satellites operate in this region called low Earth orbit and must fire their engines every few days to maintain orbit.[citation needed] The drag here is low enough that it could theoretically be overcome by radiation pressure on solar sails, a proposed propulsion system for interplanetary travel.[citation needed] Planets are too massive for their trajectories to be significantly affected by these forces, although their atmospheres are eroded by the solar winds.

Questions and answers:
['
Q: Where do most satellites operate?
A: low Earth orbit', '
Q: What system could possibly be used for interplanetary travel?
A: solar sails', '
Q: why do satellites need to fire engines every few day to keep orbit?
A: atmospheric density', '
Q: above what line location in outer space to satellites orbit?
A: Kármán line']
In the medieval Middle Eastern world, the physicist and Islamic scholar, Al-Farabi (Alpharabius, 872–950), conducted a small experiment concerning the existence of vacuum, in which he investigated handheld plungers in water.[unreliable source?] He concluded that air's volume can expand to fill available space, and he suggested that the concept of perfect vacuum was incoherent. However, according to Nader El-Bizri, the physicist Ibn al-Haytham (Alhazen, 965–1039) and the Mu'tazili theologians disagreed with Aristotle and Al-Farabi, and they supported the existence of a void. Using geometry, Ibn al-Haytham mathematically demonstrated that place (al-makan) is the imagined three-dimensional void between the inner surfaces of a containing body. According to Ahmad Dallal, Abū Rayhān al-Bīrūnī also states that "there is no observable evidence that rules out the possibility of vacuum". The suction pump later appeared in Europe from the 15th century.

Questions and answers:
['
Q: Al-Farabi concluded a perfect vacuum was incoherent using what?
A: handheld plungers in water.', '
Q: Ibn al-Haytham used geometry to demonstrate  what?
A: place (al-makan) is the imagined three-dimensional void between the inner surfaces of a containing body', '
Q: who stated that there was no evidence to rule out a vacuum?
A: Abū Rayhān al-Bīrūnī', "
Q: what did Al-Farabi say expanded to fill available space
A: air's volume", '
Q: What type of pump appeared in the 15th century?
A: suction pump']
Medieval thought experiments 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 Walter Burley postulated, whether a 'celestial agent' prevented the vacuum arising. The commonly held view that nature abhorred a vacuum was called horror vacui. Speculation that even God could not create a vacuum if he wanted to was shut down[clarification needed] by the 1277 Paris condemnations of Bishop Etienne Tempier, which required there to be no restrictions on the powers of God, which led to the conclusion that God could create a vacuum if he so wished. Jean Buridan reported in the 14th century that teams of ten horses could not pull open bellows when the port was sealed.

Questions and answers:
["
Q: Who required no restrictions regarding God's power?
A: Bishop Etienne Tempier", '
Q: When did Buridan state that teams of ten horses could not open a bellow with a sealed port?
A: 14th century', '
Q: the 1277 Paris Condemnations led to what conclusion?
A: God could create a vacuum if he so wished.', '
Q: What was a common belief about vacuums and nature?
A: nature abhorred a vacuum', '
Q: what was the belief that nature abhorred a vaccuum called?
A: horror vacui']
In 1654, Otto von Guericke invented the first vacuum pump and conducted his famous Magdeburg hemispheres experiment, showing that teams of horses could not separate two hemispheres from which the air had been partially evacuated. Robert Boyle improved Guericke's design and with the help of Robert Hooke further developed vacuum pump technology. Thereafter, research into the partial vacuum lapsed until 1850 when August Toepler invented the Toepler Pump and Heinrich Geissler invented the mercury displacement pump in 1855, achieving a partial vacuum of about 10 Pa (0.1 Torr). A number of electrical properties become observable at this vacuum level, which renewed interest in further research.

Questions and answers:
['
Q: What was the vacuum created by the mercury displacement pump?
A: partial vacuum of about 10 Pa (0.1 Torr).', '
Q: What year was the Toepler Pump invented?
A: 1850', '
Q: What was first invented by Otto von Guericke ?
A: vacuum pump', '
Q: Who conducted the Magdeburg experiment?
A: Otto von Guericke', '
Q: What was made visible at a partial vacuum of 10 Pa?
A: A number of electrical properties']
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 aether. Borrowing somewhat from the pneuma of Stoic physics, aether came to be regarded as the rarefied air from which it took its name, (see Aether (mythology)). Early theories of light posited a ubiquitous terrestrial and celestial medium through which light propagated. Additionally, the concept informed Isaac Newton's explanations of both refraction and of radiant heat. 19th century experiments into this luminiferous aether 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, astronomer Henry Pickering commented: "While the interstellar absorbing medium may be simply the ether, [it] is characteristic of a gas, and free gaseous molecules are certainly there".

Questions and answers:
['
Q: What was originally believed the heavens were filled with?
A: aether', '
Q: Why were experiments done on luminiferous aether in the 19 Century?
A: "While the interstellar absorbing medium may be simply the ether, [it] is characteris', '
Q: Who stated that the character of a gas and free molecule were in ether?
A: Henry Pickering', '
Q: Where are the highest amounts of naturally occurring partial vacuums?
A: outer space', '
Q: What was ether originally thought to be made of?
A: rigid indestructible material']
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 absolute pressure, but a complete characterization requires further parameters, such as temperature and chemical composition. One of the most important parameters is the mean free path (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 fluid mechanics do not apply. This vacuum state is called high vacuum, and the study of fluid flows in this regime is called particle gas dynamics. The MFP of air at atmospheric pressure is very short, 70 nm, but at 100 mPa (~6997100000000000000♠1×10−3 Torr) the MFP of room temperature air is roughly 100 mm, which is on the order of everyday objects such as vacuum tubes. The Crookes radiometer turns when the MFP is larger than the size of the vanes.

Questions and answers:
['
Q: What indicated the quality of a vacuum?
A: amount of matter remaining in the system', '
Q: How is vacuum generally measured?
A: its absolute pressure', '
Q: What does the MFP of residual gases show?
A: average distance that molecules will travel between collisions with each other.', '
Q: What is particle gas dynamics?
A: study of fluid flows']
The SI unit of pressure is the pascal (symbol Pa), but vacuum is often measured in torrs, named for Torricelli, an early Italian physicist (1608–1647). A torr is equal to the displacement of a millimeter of mercury (mmHg) in a manometer with 1 torr equaling 133.3223684 pascals above absolute zero pressure. Vacuum is often also measured on the barometric scale or as a percentage of atmospheric pressure in bars or atmospheres. Low vacuum is often measured in millimeters of mercury (mmHg) or pascals (Pa) below standard atmospheric pressure. "Below atmospheric" means that the absolute pressure is equal to the current atmospheric pressure.

Questions and answers:
['
Q: Absolute pressure  being equal to current atmospheric pressure means what?
A: "Below atmospheric"', '
Q: What is a torr equal to?
A: displacement of a millimeter of mercury', '
Q: What is another often used options to measure vacuum?
A: barometric scale']
Hydrostatic gauges (such as the mercury column manometer) 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 mercury 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 McLeod gauge 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 10−6 torr (0.1 mPa), which is the lowest direct measurement of pressure that is possible with current technology. Other vacuum 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.

Questions and answers:
['
Q: Why is mercury the better option for liquid used in a Hydrostatic gauge?
A: its high density and low vapour pressure', '
Q: What is a vertical column of liquid in a tube which has different pressures at each end called?
A: Hydrostatic gauges', '
Q: What is a hydrostatic gauge used for?
A: measure pressures ranging from 1 torr (100 Pa) to above atmospheric', '
Q: Why is the McLeod gauge special?
A: can measure vacuums as high as 10−6 torr', '
Q: An indirect measurement of pressure is most often calibrated by what?
A: McLeod gauge']
Thermal conductivity 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 thermocouple or Resistance Temperature Detector (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 Pirani gauge which uses a single platinum filament as both the heated element and RTD. These gauges are accurate from 10 torr to 10−3 torr, but they are sensitive to the chemical composition of the gases being measured.

Questions and answers:
['
Q: The fact that gases ability to conduct heat decreases with pressure is used by what form of measurement?
A: Thermal conductivity gauges', '
Q: How is the wire filament in a Thermal conductivity gauge heated?
A: by running current through it', '
Q: What is a Pirani gauge sensitive to?
A: chemical composition of the gases being measured', '
Q: What is a RTD used for on a Thermal Conductivity gauge?
A: to measure the temperature of the filament', '
Q: A Pirani gauge is accurate within what ranges?
A: 10 torr to 10−3 torr']
Ion gauges are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the hot cathode 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 gauges are accurate from 10−3 torr to 10−10 torr. The principle behind cold cathode 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 10−2 torr to 10−9 torr. Ionization gauge calibration is very sensitive to construction geometry, chemical composition of gases being 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.

Questions and answers:
['
Q: What affects the number of ions in a gauge?
A: the pressure in the gauge', '
Q: What must be used for accurate measurement on the composition of gases at a high vacuums?
A: mass spectrometer must be used in conjunction with the ionization gauge', '
Q: What gauge is accurate from 10-2 torr to 10-9 torr?
A: Cold cathode gauges', '
Q: Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement?
A: composition of gases at high vacuums will usually be unpredictable', '
Q: What are the two types of Ion gauges?
A: hot cathode and cold cathode.']
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 this altitude, oxygen enrichment is necessary to prevent altitude sickness in humans that did not undergo prior acclimatization, and spacesuits 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 decompression sickness and gas embolisms can still occur if decompression rates are not managed.

Questions and answers:
['
Q: density of oxygen like that of sea-level atmosphere is needed to do what?
A: sustain life at pressures much lower than atmospheric,', '
Q: What is the lowest altitude where acclimatization or a suit is not needed to prevent sickness in humans?
A: of up to 3 km']
Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia 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 internal body temperature of 37 °C. Although the blood will not boil, the formation of gas bubbles in bodily fluids at reduced pressures, known as ebullism, is still a concern. The gas may bloat the body to twice its normal size and slow circulation, but tissues are elastic and porous enough to prevent rupture. Swelling and ebullism can be restrained by containment in a flight suit. Shuttle 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.

Questions and answers:
['
Q: When will a person or animal lose consciousness  when exposed to a vacuum?
A: after a few seconds', '
Q: A shuttle astronauts prevents ebullism at 2 kPa with what item?
A: the Crew Altitude Protection Suit (CAPS)', '
Q: What is the forming of gas bubbles in body fluids at a lowered pressure called?
A: ebullism', '
Q: What prevents body rupture at low altitude when human body is bloated by gas bubbles?
A: tissues are elastic and porous']
In ultra high vacuum systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or titanium 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.

Questions and answers:
['
Q: What can boil away in extreme vaccum exposure?
A: Some oils and greases', '
Q: How should the grain direct of metallic flanges run to flange faces?
A: parallel', '
Q: What are 2 metals that can be absorbed in an ultra high vacuum system?
A: stainless steel or titanium', '
Q: What becomes a concern in an ultra high vacuum system regarding aluminum or palladium?
A: water absorption']