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| question
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| references
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|---|---|---|---|---|---|---|---|
gem-squad_v2-train-113400
|
5a87817f1d3cee001a6a11fe
|
Vacuum
|
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".
|
What is another name for mythology?
|
What is another name for mythology?
|
[
"What is another name for mythology?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113401
|
5a87817f1d3cee001a6a11ff
|
Vacuum
|
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".
|
Where did the ideas about the properties of molecules come from?
|
Where did the ideas about the properties of molecules come from?
|
[
"Where did the ideas about the properties of molecules come from?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113402
|
5a87817f1d3cee001a6a1200
|
Vacuum
|
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".
|
What did experiments with molecules attempt to detect on the Earths orbit?
|
What did experiments with molecules attempt to detect on the Earths orbit?
|
[
"What did experiments with molecules attempt to detect on the Earths orbit?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113403
|
572ebf10c246551400ce45e6
|
Vacuum
|
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.
|
What indicated the quality of a vacuum?
|
What indicated the quality of a vacuum?
|
[
"What indicated the quality of a vacuum?"
] |
{
"text": [
"amount of matter remaining in the system"
],
"answer_start": [
44
]
}
|
gem-squad_v2-train-113404
|
572ebf10c246551400ce45e7
|
Vacuum
|
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.
|
How is vacuum generally measured?
|
How is vacuum generally measured?
|
[
"How is vacuum generally measured?"
] |
{
"text": [
"its absolute pressure"
],
"answer_start": [
191
]
}
|
gem-squad_v2-train-113405
|
572ebf10c246551400ce45e8
|
Vacuum
|
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.
|
What does the MFP of residual gases show?
|
What does the MFP of residual gases show?
|
[
"What does the MFP of residual gases show?"
] |
{
"text": [
"average distance that molecules will travel between collisions with each other."
],
"answer_start": [
425
]
}
|
gem-squad_v2-train-113406
|
572ebf10c246551400ce45e9
|
Vacuum
|
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.
|
What is particle gas dynamics?
|
What is particle gas dynamics?
|
[
"What is particle gas dynamics?"
] |
{
"text": [
"study of fluid flows"
],
"answer_start": [
751
]
}
|
gem-squad_v2-train-113407
|
5a8793d01d3cee001a6a126a
|
Vacuum
|
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.
|
What indicates the quality of residual gases?
|
What indicates the quality of residual gases?
|
[
"What indicates the quality of residual gases?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113408
|
5a8793d01d3cee001a6a126b
|
Vacuum
|
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.
|
How much matter is left in residual gases?
|
How much matter is left in residual gases?
|
[
"How much matter is left in residual gases?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113409
|
5a8793d01d3cee001a6a126c
|
Vacuum
|
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.
|
How are residual gases measured?
|
How are residual gases measured?
|
[
"How are residual gases measured?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113410
|
5a8793d01d3cee001a6a126d
|
Vacuum
|
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.
|
What other factors are necessary to measure residual gases?
|
What other factors are necessary to measure residual gases?
|
[
"What other factors are necessary to measure residual gases?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113411
|
5a8793d01d3cee001a6a126e
|
Vacuum
|
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.
|
What is the study of residual gases in a spacecraft called?
|
What is the study of residual gases in a spacecraft called?
|
[
"What is the study of residual gases in a spacecraft called?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113412
|
572ec078c246551400ce460a
|
Vacuum
|
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.
|
Absolute pressure being equal to current atmospheric pressure means what?
|
Absolute pressure being equal to current atmospheric pressure means what?
|
[
"Absolute pressure being equal to current atmospheric pressure means what?"
] |
{
"text": [
"\"Below atmospheric\""
],
"answer_start": [
544
]
}
|
gem-squad_v2-train-113413
|
572ec078c246551400ce460b
|
Vacuum
|
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.
|
What is a torr equal to?
|
What is a torr equal to?
|
[
"What is a torr equal to?"
] |
{
"text": [
"displacement of a millimeter of mercury"
],
"answer_start": [
175
]
}
|
gem-squad_v2-train-113414
|
572ec078c246551400ce460c
|
Vacuum
|
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.
|
What is another often used options to measure vacuum?
|
What is another often used options to measure vacuum?
|
[
"What is another often used options to measure vacuum?"
] |
{
"text": [
"barometric scale"
],
"answer_start": [
345
]
}
|
gem-squad_v2-train-113415
|
5a8797e11d3cee001a6a127e
|
Vacuum
|
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.
|
During what years was mercury commonly in use?
|
During what years was mercury commonly in use?
|
[
"During what years was mercury commonly in use?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113416
|
5a8797e11d3cee001a6a127f
|
Vacuum
|
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.
|
What is the barometric scale equal to?
|
What is the barometric scale equal to?
|
[
"What is the barometric scale equal to?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113417
|
5a8797e11d3cee001a6a1280
|
Vacuum
|
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.
|
What element did Torricelli discover in 1608?
|
What element did Torricelli discover in 1608?
|
[
"What element did Torricelli discover in 1608?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113418
|
5a8797e11d3cee001a6a1281
|
Vacuum
|
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.
|
How many pascals does the barometric scale equal?
|
How many pascals does the barometric scale equal?
|
[
"How many pascals does the barometric scale equal?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113419
|
5a8797e11d3cee001a6a1282
|
Vacuum
|
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.
|
What is another way to measure the state of being below atmospheric?
|
What is another way to measure the state of being below atmospheric?
|
[
"What is another way to measure the state of being below atmospheric?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113420
|
572ec1b6c246551400ce461a
|
Vacuum
|
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.
|
Why is mercury the better option for liquid used in a Hydrostatic gauge?
|
Why is mercury the better option for liquid used in a Hydrostatic gauge?
|
[
"Why is mercury the better option for liquid used in a Hydrostatic gauge?"
] |
{
"text": [
"its high density and low vapour pressure"
],
"answer_start": [
444
]
}
|
gem-squad_v2-train-113421
|
572ec1b6c246551400ce461b
|
Vacuum
|
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.
|
What is a vertical column of liquid in a tube which has different pressures at each end called?
|
What is a vertical column of liquid in a tube which has different pressures at each end called?
|
[
"What is a vertical column of liquid in a tube which has different pressures at each end called?"
] |
{
"text": [
"Hydrostatic gauges"
],
"answer_start": [
0
]
}
|
gem-squad_v2-train-113422
|
572ec1b6c246551400ce461c
|
Vacuum
|
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.
|
What is a hydrostatic gauge used for?
|
What is a hydrostatic gauge used for?
|
[
"What is a hydrostatic gauge used for?"
] |
{
"text": [
"measure pressures ranging from 1 torr (100 Pa) to above atmospheric"
],
"answer_start": [
516
]
}
|
gem-squad_v2-train-113423
|
572ec1b6c246551400ce461d
|
Vacuum
|
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.
|
Why is the McLeod gauge special?
|
Why is the McLeod gauge special?
|
[
"Why is the McLeod gauge special?"
] |
{
"text": [
"can measure vacuums as high as 10−6 torr"
],
"answer_start": [
758
]
}
|
gem-squad_v2-train-113424
|
572ec1b6c246551400ce461e
|
Vacuum
|
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.
|
An indirect measurement of pressure is most often calibrated by what?
|
An indirect measurement of pressure is most often calibrated by what?
|
[
"An indirect measurement of pressure is most often calibrated by what?"
] |
{
"text": [
"McLeod gauge"
],
"answer_start": [
1117
]
}
|
gem-squad_v2-train-113425
|
5a87a0cc1d3cee001a6a129c
|
Vacuum
|
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.
|
What is the level of mercury in the air calibrated by?
|
What is the level of mercury in the air calibrated by?
|
[
"What is the level of mercury in the air calibrated by?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113426
|
5a87a0cc1d3cee001a6a129d
|
Vacuum
|
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.
|
What is the density level of mercury in the air?
|
What is the density level of mercury in the air?
|
[
"What is the density level of mercury in the air?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113427
|
5a87a0cc1d3cee001a6a129e
|
Vacuum
|
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.
|
What is used to measure mercury in the air?
|
What is used to measure mercury in the air?
|
[
"What is used to measure mercury in the air?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113428
|
5a87a0cc1d3cee001a6a129f
|
Vacuum
|
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.
|
What is the lowest amount of mercury that can be measured in the air?
|
What is the lowest amount of mercury that can be measured in the air?
|
[
"What is the lowest amount of mercury that can be measured in the air?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113429
|
5a87a0cc1d3cee001a6a12a0
|
Vacuum
|
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.
|
What measurements are used to measure mercury in the air?
|
What measurements are used to measure mercury in the air?
|
[
"What measurements are used to measure mercury in the air?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113430
|
572ec300c246551400ce4624
|
Vacuum
|
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.
|
The fact that gases ability to conduct heat decreases with pressure is used by what form of measurement?
|
The fact that gases ability to conduct heat decreases with pressure is used by what form of measurement?
|
[
"The fact that gases ability to conduct heat decreases with pressure is used by what form of measurement?"
] |
{
"text": [
"Thermal conductivity gauges"
],
"answer_start": [
0
]
}
|
gem-squad_v2-train-113431
|
572ec300c246551400ce4625
|
Vacuum
|
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.
|
How is the wire filament in a Thermal conductivity gauge heated?
|
How is the wire filament in a Thermal conductivity gauge heated?
|
[
"How is the wire filament in a Thermal conductivity gauge heated?"
] |
{
"text": [
"by running current through it"
],
"answer_start": [
161
]
}
|
gem-squad_v2-train-113432
|
572ec300c246551400ce4626
|
Vacuum
|
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.
|
What is a Pirani gauge sensitive to?
|
What is a Pirani gauge sensitive to?
|
[
"What is a Pirani gauge sensitive to?"
] |
{
"text": [
"chemical composition of the gases being measured"
],
"answer_start": [
645
]
}
|
gem-squad_v2-train-113433
|
572ec300c246551400ce4627
|
Vacuum
|
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.
|
What is a RTD used for on a Thermal Conductivity gauge?
|
What is a RTD used for on a Thermal Conductivity gauge?
|
[
"What is a RTD used for on a Thermal Conductivity gauge?"
] |
{
"text": [
"to measure the temperature of the filament"
],
"answer_start": [
265
]
}
|
gem-squad_v2-train-113434
|
572ec300c246551400ce4628
|
Vacuum
|
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.
|
A Pirani gauge is accurate within what ranges?
|
A Pirani gauge is accurate within what ranges?
|
[
"A Pirani gauge is accurate within what ranges?"
] |
{
"text": [
"10 torr to 10−3 torr"
],
"answer_start": [
593
]
}
|
gem-squad_v2-train-113435
|
5a87aa881d3cee001a6a12c4
|
Vacuum
|
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.
|
How does plantinums ability to conduct heat decrease?
|
How does plantinums ability to conduct heat decrease?
|
[
"How does plantinums ability to conduct heat decrease?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113436
|
5a87aa881d3cee001a6a12c5
|
Vacuum
|
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.
|
What kind of filament does the RTD use?
|
What kind of filament does the RTD use?
|
[
"What kind of filament does the RTD use?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113437
|
5a87aa881d3cee001a6a12c6
|
Vacuum
|
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.
|
How do thermal conductivity gauges use a single platinum filament as?
|
How do thermal conductivity gauges use a single platinum filament as?
|
[
"How do thermal conductivity gauges use a single platinum filament as?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113438
|
5a87aa881d3cee001a6a12c7
|
Vacuum
|
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.
|
How quickly does a filament lose heat?
|
How quickly does a filament lose heat?
|
[
"How quickly does a filament lose heat?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113439
|
5a87aa881d3cee001a6a12c8
|
Vacuum
|
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.
|
Pressure is sensitive to the heated element of what?
|
Pressure is sensitive to the heated element of what?
|
[
"Pressure is sensitive to the heated element of what?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113440
|
572ec42ecb0c0d14000f151a
|
Vacuum
|
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.
|
What are the two types of Ion gauges?
|
What are the two types of Ion gauges?
|
[
"What are the two types of Ion gauges?"
] |
{
"text": [
"hot cathode and cold cathode."
],
"answer_start": [
65
]
}
|
gem-squad_v2-train-113441
|
572ec42ecb0c0d14000f151b
|
Vacuum
|
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.
|
What affects the number of ions in a gauge?
|
What affects the number of ions in a gauge?
|
[
"What affects the number of ions in a gauge?"
] |
{
"text": [
"the pressure in the gauge"
],
"answer_start": [
376
]
}
|
gem-squad_v2-train-113442
|
572ec42ecb0c0d14000f151c
|
Vacuum
|
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.
|
What gauge is accurate from 10-2 torr to 10-9 torr?
|
What gauge is accurate from 10-2 torr to 10-9 torr?
|
[
"What gauge is accurate from 10-2 torr to 10-9 torr?"
] |
{
"text": [
"Cold cathode gauges"
],
"answer_start": [
618
]
}
|
gem-squad_v2-train-113443
|
572ec42ecb0c0d14000f151d
|
Vacuum
|
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.
|
What must be used for accurate measurement on the composition of gases at a high vacuums?
|
What must be used for accurate measurement on the composition of gases at a high vacuums?
|
[
"What must be used for accurate measurement on the composition of gases at a high vacuums?"
] |
{
"text": [
"mass spectrometer must be used in conjunction with the ionization gauge"
],
"answer_start": [
998
]
}
|
gem-squad_v2-train-113444
|
572ec42ecb0c0d14000f151e
|
Vacuum
|
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.
|
Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement?
|
Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement?
|
[
"Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement?"
] |
{
"text": [
"composition of gases at high vacuums will usually be unpredictable"
],
"answer_start": [
925
]
}
|
gem-squad_v2-train-113445
|
5a87ad601d3cee001a6a12ce
|
Vacuum
|
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.
|
What are the two types of mass spectrometers?
|
What are the two types of mass spectrometers?
|
[
"What are the two types of mass spectrometers?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113446
|
5a87ad601d3cee001a6a12cf
|
Vacuum
|
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.
|
In the hot cathode version what does corrosion produce?
|
In the hot cathode version what does corrosion produce?
|
[
"In the hot cathode version what does corrosion produce?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113447
|
5a87ad601d3cee001a6a12d0
|
Vacuum
|
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.
|
What is ionized when electrodes travel through a mass spectrometer?
|
What is ionized when electrodes travel through a mass spectrometer?
|
[
"What is ionized when electrodes travel through a mass spectrometer?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113448
|
5a87ad601d3cee001a6a12d1
|
Vacuum
|
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.
|
What is the accuracy of a mass spectrometer?
|
What is the accuracy of a mass spectrometer?
|
[
"What is the accuracy of a mass spectrometer?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113449
|
5a87ad601d3cee001a6a12d2
|
Vacuum
|
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.
|
What is the nature of electrically heated filaments at high vacuums?
|
What is the nature of electrically heated filaments at high vacuums?
|
[
"What is the nature of electrically heated filaments at high vacuums?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113450
|
572ec82acb0c0d14000f1558
|
Vacuum
|
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.
|
density of oxygen like that of sea-level atmosphere is needed to do what?
|
density of oxygen like that of sea-level atmosphere is needed to do what?
|
[
"density of oxygen like that of sea-level atmosphere is needed to do what?"
] |
{
"text": [
"sustain life at pressures much lower than atmospheric,"
],
"answer_start": [
36
]
}
|
gem-squad_v2-train-113451
|
572ec82acb0c0d14000f1559
|
Vacuum
|
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.
|
What is the lowest altitude where acclimatization or a suit is not needed to prevent sickness in humans?
|
What is the lowest altitude where acclimatization or a suit is not needed to prevent sickness in humans?
|
[
"What is the lowest altitude where acclimatization or a suit is not needed to prevent sickness in humans?"
] |
{
"text": [
"of up to 3 km"
],
"answer_start": [
224
]
}
|
gem-squad_v2-train-113452
|
5a87d2c819b91f001a626e33
|
Vacuum
|
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.
|
What do colder air temperatures found at altitudes above 19km compensate for?
|
What do colder air temperatures found at altitudes above 19km compensate for?
|
[
"What do colder air temperatures found at altitudes above 19km compensate for?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113453
|
5a87d2c819b91f001a626e34
|
Vacuum
|
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.
|
What is needed at altitudes of up to 3km to prevent altitiude sickness?
|
What is needed at altitudes of up to 3km to prevent altitiude sickness?
|
[
"What is needed at altitudes of up to 3km to prevent altitiude sickness?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113454
|
5a87d2c819b91f001a626e35
|
Vacuum
|
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.
|
What do cold or oxygen-rich atmospheres usuall cause?
|
What do cold or oxygen-rich atmospheres usuall cause?
|
[
"What do cold or oxygen-rich atmospheres usuall cause?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113455
|
5a87d2c819b91f001a626e36
|
Vacuum
|
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.
|
How much pure oxygen is in the atmosphere?
|
How much pure oxygen is in the atmosphere?
|
[
"How much pure oxygen is in the atmosphere?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113456
|
5a87d2c819b91f001a626e37
|
Vacuum
|
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.
|
When people are acclimated to the altitude, gas embolisms and what can happen?
|
When people are acclimated to the altitude, gas embolisms and what can happen?
|
[
"When people are acclimated to the altitude, gas embolisms and what can happen?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113457
|
572ec989dfa6aa1500f8d3bd
|
Vacuum
|
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.
|
When will a person or animal lose consciousness when exposed to a vacuum?
|
When will a person or animal lose consciousness when exposed to a vacuum?
|
[
"When will a person or animal lose consciousness when exposed to a vacuum?"
] |
{
"text": [
"after a few seconds"
],
"answer_start": [
61
]
}
|
gem-squad_v2-train-113458
|
572ec989dfa6aa1500f8d3be
|
Vacuum
|
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.
|
A shuttle astronauts prevents ebullism at 2 kPa with what item?
|
A shuttle astronauts prevents ebullism at 2 kPa with what item?
|
[
"A shuttle astronauts prevents ebullism at 2 kPa with what item?"
] |
{
"text": [
"the Crew Altitude Protection Suit (CAPS)"
],
"answer_start": [
836
]
}
|
gem-squad_v2-train-113459
|
572ec989dfa6aa1500f8d3bf
|
Vacuum
|
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.
|
What is the forming of gas bubbles in body fluids at a lowered pressure called?
|
What is the forming of gas bubbles in body fluids at a lowered pressure called?
|
[
"What is the forming of gas bubbles in body fluids at a lowered pressure called?"
] |
{
"text": [
"ebullism"
],
"answer_start": [
720
]
}
|
gem-squad_v2-train-113460
|
572ec989dfa6aa1500f8d3c0
|
Vacuum
|
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.
|
What prevents body rupture at low altitude when human body is bloated by gas bubbles?
|
What prevents body rupture at low altitude when human body is bloated by gas bubbles?
|
[
"What prevents body rupture at low altitude when human body is bloated by gas bubbles?"
] |
{
"text": [
"tissues are elastic and porous"
],
"answer_start": [
649
]
}
|
gem-squad_v2-train-113461
|
5a87cf7419b91f001a626e15
|
Vacuum
|
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.
|
At what temperature does frost usually occur in space?
|
At what temperature does frost usually occur in space?
|
[
"At what temperature does frost usually occur in space?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113462
|
5a87cf7419b91f001a626e16
|
Vacuum
|
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.
|
When exposed to frost who will die from ebullism within minutes?
|
When exposed to frost who will die from ebullism within minutes?
|
[
"When exposed to frost who will die from ebullism within minutes?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113463
|
5a87cf7419b91f001a626e17
|
Vacuum
|
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.
|
What will frost cause in body fluids at reduced pressures?
|
What will frost cause in body fluids at reduced pressures?
|
[
"What will frost cause in body fluids at reduced pressures?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113464
|
5a87cf7419b91f001a626e18
|
Vacuum
|
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.
|
What can a person wear to prevent frost on the skin?
|
What can a person wear to prevent frost on the skin?
|
[
"What can a person wear to prevent frost on the skin?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113465
|
5a87cf7419b91f001a626e19
|
Vacuum
|
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.
|
What does a CAPS suit prevent frost at pressures as low as?
|
What does a CAPS suit prevent frost at pressures as low as?
|
[
"What does a CAPS suit prevent frost at pressures as low as?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113466
|
572eca8ccb0c0d14000f1576
|
Vacuum
|
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.
|
What can boil away in extreme vaccum exposure?
|
What can boil away in extreme vaccum exposure?
|
[
"What can boil away in extreme vaccum exposure?"
] |
{
"text": [
"Some oils and greases"
],
"answer_start": [
294
]
}
|
gem-squad_v2-train-113467
|
572eca8ccb0c0d14000f1577
|
Vacuum
|
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.
|
How should the grain direct of metallic flanges run to flange faces?
|
How should the grain direct of metallic flanges run to flange faces?
|
[
"How should the grain direct of metallic flanges run to flange faces?"
] |
{
"text": [
"parallel"
],
"answer_start": [
482
]
}
|
gem-squad_v2-train-113468
|
572eca8ccb0c0d14000f1578
|
Vacuum
|
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.
|
What are 2 metals that can be absorbed in an ultra high vacuum system?
|
What are 2 metals that can be absorbed in an ultra high vacuum system?
|
[
"What are 2 metals that can be absorbed in an ultra high vacuum system?"
] |
{
"text": [
"stainless steel or titanium"
],
"answer_start": [
246
]
}
|
gem-squad_v2-train-113469
|
572eca8ccb0c0d14000f1579
|
Vacuum
|
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.
|
What becomes a concern in an ultra high vacuum system regarding aluminum or palladium?
|
What becomes a concern in an ultra high vacuum system regarding aluminum or palladium?
|
[
"What becomes a concern in an ultra high vacuum system regarding aluminum or palladium?"
] |
{
"text": [
"water absorption"
],
"answer_start": [
107
]
}
|
gem-squad_v2-train-113470
|
5a87cd0419b91f001a626df7
|
Vacuum
|
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.
|
What will boil off when aluminum absorbs water?
|
What will boil off when aluminum absorbs water?
|
[
"What will boil off when aluminum absorbs water?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113471
|
5a87cd0419b91f001a626df8
|
Vacuum
|
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.
|
How should palladium be placed when it has oil on it?
|
How should palladium be placed when it has oil on it?
|
[
"How should palladium be placed when it has oil on it?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113472
|
5a87cd0419b91f001a626df9
|
Vacuum
|
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.
|
What are two metals that can be absorbed in an metallic flange?
|
What are two metals that can be absorbed in an metallic flange?
|
[
"What are two metals that can be absorbed in an metallic flange?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113473
|
5a87cd0419b91f001a626dfa
|
Vacuum
|
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.
|
In what area will water boil off?
|
In what area will water boil off?
|
[
"In what area will water boil off?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113474
|
5a87cd0419b91f001a626dfb
|
Vacuum
|
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.
|
What will grease usually run parallel to?
|
What will grease usually run parallel to?
|
[
"What will grease usually run parallel to?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113475
|
572ecbdddfa6aa1500f8d3cb
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
The state with the lowest possible energy in quantum mechanics defines what ?
|
The state with the lowest possible energy in quantum mechanics defines what ?
|
[
"The state with the lowest possible energy in quantum mechanics defines what ?"
] |
{
"text": [
"vacuum"
],
"answer_start": [
51
]
}
|
gem-squad_v2-train-113476
|
572ecbdddfa6aa1500f8d3cc
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
A vacuum state with no matter particles or photons is called what?
|
A vacuum state with no matter particles or photons is called what?
|
[
"A vacuum state with no matter particles or photons is called what?"
] |
{
"text": [
"QED"
],
"answer_start": [
364
]
}
|
gem-squad_v2-train-113477
|
572ecbdddfa6aa1500f8d3cd
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
why is a QED vacuum impossible to achieve ?
|
why is a QED vacuum impossible to achieve ?
|
[
"why is a QED vacuum impossible to achieve ?"
] |
{
"text": [
"impossible to eliminate all the blackbody photons"
],
"answer_start": [
605
]
}
|
gem-squad_v2-train-113478
|
572ecbdddfa6aa1500f8d3ce
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
What is a QCD?
|
What is a QCD?
|
[
"What is a QCD?"
] |
{
"text": [
"vacuum of quantum chromodynamics,"
],
"answer_start": [
307
]
}
|
gem-squad_v2-train-113479
|
5a878b751d3cee001a6a1224
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
What are blackbody photons in quantum mechanics?
|
What are blackbody photons in quantum mechanics?
|
[
"What are blackbody photons in quantum mechanics?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113480
|
5a878b751d3cee001a6a1225
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
What do blackbody photons with no matter particles or photons form?
|
What do blackbody photons with no matter particles or photons form?
|
[
"What do blackbody photons with no matter particles or photons form?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113481
|
5a878b751d3cee001a6a1226
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
Why is a blackbody field impossible to achieve?
|
Why is a blackbody field impossible to achieve?
|
[
"Why is a blackbody field impossible to achieve?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113482
|
5a878b751d3cee001a6a1227
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
What would you need to remove to create a blackbody field?
|
What would you need to remove to create a blackbody field?
|
[
"What would you need to remove to create a blackbody field?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113483
|
5a878b751d3cee001a6a1228
|
Vacuum
|
In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.
|
What is a blackbody photon referred to in quantum mechanics?
|
What is a blackbody photon referred to in quantum mechanics?
|
[
"What is a blackbody photon referred to in quantum mechanics?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113484
|
572ecd51c246551400ce46ae
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
When are electric and magnetic fields with zero average values, but their variances are not at zero?
|
When are electric and magnetic fields with zero average values, but their variances are not at zero?
|
[
"When are electric and magnetic fields with zero average values, but their variances are not at zero?"
] |
{
"text": [
"In QED vacuum"
],
"answer_start": [
51
]
}
|
gem-squad_v2-train-113485
|
572ecd51c246551400ce46af
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What is a verified effect of vacuum fluctuation?
|
What is a verified effect of vacuum fluctuation?
|
[
"What is a verified effect of vacuum fluctuation?"
] |
{
"text": [
"spontaneous emission"
],
"answer_start": [
460
]
}
|
gem-squad_v2-train-113486
|
572ecd51c246551400ce46b0
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
what is vacuum fluctuation?
|
what is vacuum fluctuation?
|
[
"what is vacuum fluctuation?"
] |
{
"text": [
"virtual particles that hop into and out of existence"
],
"answer_start": [
213
]
}
|
gem-squad_v2-train-113487
|
572ecd51c246551400ce46b1
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
Finite energy in a QED is called what?
|
Finite energy in a QED is called what?
|
[
"Finite energy in a QED is called what?"
] |
{
"text": [
"vacuum energy"
],
"answer_start": [
295
]
}
|
gem-squad_v2-train-113488
|
572ecd51c246551400ce46b2
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What modifies can Coulomb's Law in a vacuum?
|
What modifies can Coulomb's Law in a vacuum?
|
[
"What modifies can Coulomb's Law in a vacuum?"
] |
{
"text": [
"vacuum near an electric charge"
],
"answer_start": [
545
]
}
|
gem-squad_v2-train-113489
|
5a878e111d3cee001a6a1242
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What part of quantum field theory are electric and magnetic fields?
|
What part of quantum field theory are electric and magnetic fields?
|
[
"What part of quantum field theory are electric and magnetic fields?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113490
|
5a878e111d3cee001a6a1243
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What kind of properties does Coulomb's law have?
|
What kind of properties does Coulomb's law have?
|
[
"What kind of properties does Coulomb's law have?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113491
|
5a878e111d3cee001a6a1244
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What values does vacuum energy have under Coulomb's law?
|
What values does vacuum energy have under Coulomb's law?
|
[
"What values does vacuum energy have under Coulomb's law?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113492
|
5a878e111d3cee001a6a1245
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What are the variances of vacuum energy according to Coulomb's law?
|
What are the variances of vacuum energy according to Coulomb's law?
|
[
"What are the variances of vacuum energy according to Coulomb's law?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113493
|
5a878e111d3cee001a6a1246
|
Vacuum
|
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 vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum fluctuations are an essential and ubiquitous part of quantum field theory. Some experimentally verified effects of vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and the electric potential in vacuum near an electric charge are modified.
|
What do particles defined in Colombo's law do?
|
What do particles defined in Colombo's law do?
|
[
"What do particles defined in Colombo's law do?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113494
|
572ece9bcb0c0d14000f15ac
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
`Why does thermosphere past the Karman line vary so greatly?
|
`Why does thermosphere past the Karman line vary so greatly?
|
[
"`Why does thermosphere past the Karman line vary so greatly?"
] |
{
"text": [
"due to space weather"
],
"answer_start": [
757
]
}
|
gem-squad_v2-train-113495
|
572ece9bcb0c0d14000f15ad
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
What is commonly known as the boundary of outer space?
|
What is commonly known as the boundary of outer space?
|
[
"What is commonly known as the boundary of outer space?"
] |
{
"text": [
"the Kármán line"
],
"answer_start": [
338
]
}
|
gem-squad_v2-train-113496
|
572ece9bcb0c0d14000f15ae
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
What do Astrophysicists use to describe outer space beyond the karman line?
|
What do Astrophysicists use to describe outer space beyond the karman line?
|
[
"What do Astrophysicists use to describe outer space beyond the karman line?"
] |
{
"text": [
"number density"
],
"answer_start": [
809
]
}
|
gem-squad_v2-train-113497
|
572ece9bcb0c0d14000f15af
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
What is more significant than isotropic gas pressure past the Karman line?
|
What is more significant than isotropic gas pressure past the Karman line?
|
[
"What is more significant than isotropic gas pressure past the Karman line?"
] |
{
"text": [
"radiation pressure from the Sun and the dynamic pressure of the solar winds"
],
"answer_start": [
506
]
}
|
gem-squad_v2-train-113498
|
5a878fa71d3cee001a6a124c
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
What is commonly known as the boundary of the Sun?
|
What is commonly known as the boundary of the Sun?
|
[
"What is commonly known as the boundary of the Sun?"
] |
{
"text": [],
"answer_start": []
}
|
gem-squad_v2-train-113499
|
5a878fa71d3cee001a6a124d
|
Vacuum
|
Stars, planets, and moons keep their atmospheres 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 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62 mi) of altitude, the Kármán line, which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the Sun and the dynamic pressure of the solar winds, so the definition of pressure becomes difficult to interpret. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre.
|
What do astrophysicists use to describe sun radiation?
|
What do astrophysicists use to describe sun radiation?
|
[
"What do astrophysicists use to describe sun radiation?"
] |
{
"text": [],
"answer_start": []
}
|
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