id stringlengths 24 24 | title stringlengths 3 59 | context stringlengths 151 3.71k | question stringlengths 12 217 | answers dict |
|---|---|---|---|---|
57296189af94a219006aa365 | Planck_constant | The assumption that black-body radiation is thermal leads to an accurate prediction: the total amount of emitted energy goes up with the temperature according to a definite rule, the Stefan–Boltzmann law (1879–84). But it was also known that the colour of the light given off by a hot object changes with the temperature... | Wien's spectrum model could not predict accurate at what end of the spectrum? | {
"text": [
"at low frequencies (long wavelength)"
],
"answer_start": [
766
]
} |
572928341d046914007790e1 | Planck_constant | Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase.... | Before Planck, it was assumed that the energy of a body could take on what value? | {
"text": [
"any"
],
"answer_start": [
84
]
} |
572928341d046914007790e2 | Planck_constant | Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase.... | The Rayleigh-Jeans law makes close predictions for what amount of values? | {
"text": [
"a narrow range"
],
"answer_start": [
193
]
} |
572928341d046914007790e3 | Planck_constant | Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase.... | What does Planck's law correctly predict? | {
"text": [
"blackbody emissions"
],
"answer_start": [
368
]
} |
572928341d046914007790e4 | Planck_constant | Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase.... | In making Planck's law, what was in both the numerator and denominator of the formula that was used? | {
"text": [
"h"
],
"answer_start": [
477
]
} |
572962c51d04691400779376 | Planck_constant | Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase.... | What rule predicted narrow range of energy values at lower temperatures? | {
"text": [
"The Rayleigh–Jeans"
],
"answer_start": [
142
]
} |
572929766aef051400154b00 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | Einstein and what other two individuals revisited the black-body problem in 1905? | {
"text": [
"Rayleigh and Jeans"
],
"answer_start": [
51
]
} |
572929766aef051400154b01 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | Who came up with the term, "ultraviolet catastrophe"? | {
"text": [
"Paul Ehrenfest"
],
"answer_start": [
304
]
} |
572929766aef051400154b02 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | When did Paul Ehrenfest come up with the name "ultraviolet catastrophe"? | {
"text": [
"1911"
],
"answer_start": [
322
]
} |
572929766aef051400154b03 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | When was the first Solvay Conference held? | {
"text": [
"1911"
],
"answer_start": [
567
]
} |
572929766aef051400154b04 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | Who received the Nobel Prize in Physics in 1918? | {
"text": [
"Max Planck"
],
"answer_start": [
625
]
} |
5729636c3f37b31900478307 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | What did Rayleigh & Jeans and Einstein prove independently in 1905? | {
"text": [
"classical electromagnetism could never account for the observed spectrum"
],
"answer_start": [
147
]
} |
5729636c3f37b31900478308 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | What name did Paul Ehrenfest give to the proofs from Einstein and Rayleigh & Jeans? | {
"text": [
"the \"ultraviolet catastrophe\""
],
"answer_start": [
256
]
} |
5729636c3f37b31900478309 | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | When was the first Solvay Conference held? | {
"text": [
"1911"
],
"answer_start": [
567
]
} |
5729636c3f37b3190047830a | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | What was the topic of the first Solvay Conference? | {
"text": [
"\"the theory of radiation and quanta\""
],
"answer_start": [
587
]
} |
5729636c3f37b3190047830b | Planck_constant | The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest i... | In what year did Planck receive the Nobel Prize in Physics for his discovery of energy quanta? | {
"text": [
"1918"
],
"answer_start": [
649
]
} |
57292b05af94a219006aa14b | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Who first observed the photoelectric effect? | {
"text": [
"Alexandre Edmond Becquerel"
],
"answer_start": [
147
]
} |
57292b05af94a219006aa14c | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | When was the photoelectric effect first observed? | {
"text": [
"1839"
],
"answer_start": [
177
]
} |
57292b05af94a219006aa14d | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Who published the first thorough investigation of the photoelectric effect? | {
"text": [
"Heinrich Hertz"
],
"answer_start": [
223
]
} |
57292b05af94a219006aa14e | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Who received the Nobel Prize in 1921 for his work on the photoelectric effect? | {
"text": [
"Einstein"
],
"answer_start": [
380
]
} |
57292b05af94a219006aa14f | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | What did Einstein with the 1921 Nobel Prize for? | {
"text": [
"his work on the photo-electric effect"
],
"answer_start": [
624
]
} |
57296497af94a219006aa374 | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Who first observed the photoelectric effect? | {
"text": [
"Alexandre Edmond Becquerel"
],
"answer_start": [
147
]
} |
57296497af94a219006aa375 | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Einstein's paper on the photoelectric effect earned him the Nobel Prize in what year? | {
"text": [
"1921"
],
"answer_start": [
483
]
} |
57296497af94a219006aa376 | Planck_constant | The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thor... | Einstein's photoelectric effect work was rewards as opposed to his work on what other topic? | {
"text": [
"relativity"
],
"answer_start": [
846
]
} |
57292c3b6aef051400154b3a | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | Before Einstein, electromagnetic radiation was considered to behave as what? | {
"text": [
"a wave"
],
"answer_start": [
103
]
} |
57292c3b6aef051400154b3b | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | What terms describe different types of radiation? | {
"text": [
"\"frequency\" and \"wavelength\""
],
"answer_start": [
138
]
} |
57292c3b6aef051400154b3c | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | What is the energy transferred by a wave in a given time called? | {
"text": [
"intensity"
],
"answer_start": [
276
]
} |
57292c3b6aef051400154b3d | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | What other types of wave besides light has its own intensity? | {
"text": [
"sound"
],
"answer_start": [
610
]
} |
5729654daf94a219006aa37b | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | Prior to Einstein's work, light behavior was modeled as what? | {
"text": [
"a wave"
],
"answer_start": [
103
]
} |
5729654daf94a219006aa37c | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | What is the name for the amount of energy transfered by a wave in a given time? | {
"text": [
"intensity"
],
"answer_start": [
276
]
} |
5729654daf94a219006aa37d | Planck_constant | Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotligh... | What portion of the photoelectric effect was in disagreement with the believed description of light behavior? | {
"text": [
"the energy account"
],
"answer_start": [
698
]
} |
57292d756aef051400154b42 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What is emitted as a result of the photoelectric effect? | {
"text": [
"photoelectrons"
],
"answer_start": [
5
]
} |
57292d756aef051400154b43 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What does the kinetic energy of a photoelectron depend on? | {
"text": [
"the frequency"
],
"answer_start": [
238
]
} |
57292d756aef051400154b44 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What happens if the photoelectron's frequency is too low? | {
"text": [
"no photoelectrons are emitted at all"
],
"answer_start": [
373
]
} |
57292d756aef051400154b45 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What is the term used when photoelectrons act virtually at the same time? | {
"text": [
"multiphoton effect"
],
"answer_start": [
543
]
} |
572969f03f37b31900478361 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What type of energy due photoelectrons emitted due to the photoelectric effect have? | {
"text": [
"kinetic"
],
"answer_start": [
84
]
} |
572969f03f37b31900478362 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | What factor of the initial light source does the energy of the photoelectrons depend on? | {
"text": [
"frequency"
],
"answer_start": [
242
]
} |
572969f03f37b31900478363 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | When the photon energy is less than the work function of the material the light is shone upon, how many photoelectrons are emitted? | {
"text": [
"no photoelectrons are emitted at all"
],
"answer_start": [
373
]
} |
572969f03f37b31900478364 | Planck_constant | The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy t... | If the photoelectric effect is occuring, increasing the intensity of the light source causes what? | {
"text": [
"more photoelectrons to be emitted with the same kinetic energy"
],
"answer_start": [
684
]
} |
57292e181d04691400779129 | Planck_constant | Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation ... | Who introduced the first quantized model of the atom? | {
"text": [
"Niels Bohr"
],
"answer_start": [
0
]
} |
57292e181d0469140077912a | Planck_constant | Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation ... | When was the first quantized model of the atom introduced? | {
"text": [
"1913"
],
"answer_start": [
63
]
} |
57292e181d0469140077912b | Planck_constant | Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation ... | Why was the first quantized model of the atom introduced? | {
"text": [
"to overcome a major shortcoming of Rutherford's classical model"
],
"answer_start": [
83
]
} |
57292e181d0469140077912c | Planck_constant | Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation ... | In classical electrodynamics, a charge moving in a circle should do what? | {
"text": [
"radiate electromagnetic radiation"
],
"answer_start": [
213
]
} |
57296aa66aef051400154e46 | Planck_constant | Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation ... | Who modeled the atom in 1913, challenging Rutherford's model? | {
"text": [
"Niels Bohr"
],
"answer_start": [
0
]
} |
57292ffa3f37b319004780bf | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | Who introduced the reduced Planck constant? | {
"text": [
"Bohr"
],
"answer_start": [
0
]
} |
57292ffa3f37b319004780c0 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | What is the reduced Planck constant also known as? | {
"text": [
"the quantity"
],
"answer_start": [
21
]
} |
57292ffa3f37b319004780c1 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | Who helped to give the correct quantization rules for electrons in 1925? | {
"text": [
"Heisenberg"
],
"answer_start": [
513
]
} |
57292ffa3f37b319004780c2 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | Who helped to give the correct quantization rules for electrons in 1926? | {
"text": [
"Schrödinger"
],
"answer_start": [
559
]
} |
57292ffa3f37b319004780c3 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | According to Heisenberg and Schrödinger, the reduced Planck constant remains what? | {
"text": [
"the fundamental quantum of angular momentum"
],
"answer_start": [
630
]
} |
57296ef4af94a219006aa3f3 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | Bohr introduced what value as the quantum of angular momentum? | {
"text": [
"the reduced Planck constant"
],
"answer_start": [
49
]
} |
57296ef4af94a219006aa3f5 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | What scientist used matrix mechanics to bring electron behavior in line with the Bohr model? | {
"text": [
"Heisenberg"
],
"answer_start": [
513
]
} |
57296ef4af94a219006aa3f6 | Planck_constant | Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angul... | When was the Schrödinger wave equation proposed? | {
"text": [
"1926"
],
"answer_start": [
588
]
} |
5729317d6aef051400154b5e | Planck_constant | where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trad... | What measurable value obeys a similar rule of angular momentum? | {
"text": [
"time vs. energy"
],
"answer_start": [
217
]
} |
5729317d6aef051400154b5f | Planck_constant | where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trad... | What forces measurement attempts to choose between trade-offs, in quanta? | {
"text": [
"either-or nature of uncertainty"
],
"answer_start": [
238
]
} |
5729317d6aef051400154b60 | Planck_constant | where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trad... | What form do measurement attempt trade-offs for quanta take the form of? | {
"text": [
"either-or (as in Fourier analysis)"
],
"answer_start": [
398
]
} |
57296f9aaf94a219006aa40e | Planck_constant | where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trad... | What type of analysis fits the either-or nature of the uncertainty? | {
"text": [
"Fourier analysis"
],
"answer_start": [
415
]
} |
57296f9aaf94a219006aa40f | Planck_constant | where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trad... | What example is given as another paired relationship of uncertainly related to standard deviation? | {
"text": [
"time vs. energy"
],
"answer_start": [
217
]
} |
5729703b1d0469140077945b | Planck_constant | The Bohr magneton and the nuclear magneton are units which are used to describe the magnetic properties of the electron and atomic nuclei respectively. The Bohr magneton is the magnetic moment which would be expected for an electron if it behaved as a spinning charge according to classical electrodynamics. It is define... | What is the unit of magentic properties of the electron? | {
"text": [
"Bohr magneton"
],
"answer_start": [
4
]
} |
5729703b1d0469140077945c | Planck_constant | The Bohr magneton and the nuclear magneton are units which are used to describe the magnetic properties of the electron and atomic nuclei respectively. The Bohr magneton is the magnetic moment which would be expected for an electron if it behaved as a spinning charge according to classical electrodynamics. It is define... | What is the unit of magentic properties of atomic nuclei? | {
"text": [
"nuclear magneton"
],
"answer_start": [
26
]
} |
5729703b1d0469140077945d | Planck_constant | The Bohr magneton and the nuclear magneton are units which are used to describe the magnetic properties of the electron and atomic nuclei respectively. The Bohr magneton is the magnetic moment which would be expected for an electron if it behaved as a spinning charge according to classical electrodynamics. It is define... | The Bohr magneton is the magnetic moment of an electron under what restriction? | {
"text": [
"behaved as a spinning charge according to classical electrodynamics"
],
"answer_start": [
239
]
} |
572970db6aef051400154ec5 | Planck_constant | In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is bas... | The value quoted here for the Planck constant is based on a measurement in what year? | {
"text": [
"2007"
],
"answer_start": [
468
]
} |
572970db6aef051400154ec6 | Planck_constant | In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is bas... | Where was this measurement made? | {
"text": [
"the U.S. National Institute of Standards and Technology (NIST)"
],
"answer_start": [
506
]
} |
572970db6aef051400154ec7 | Planck_constant | In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is bas... | What method was was used to obtain the measurement? | {
"text": [
"watt-balance measurement"
],
"answer_start": [
473
]
} |
572970db6aef051400154ec8 | Planck_constant | In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is bas... | One other measure involved the molar volume of what element? | {
"text": [
"silicon"
],
"answer_start": [
429
]
} |
572971471d0469140077946f | Planck_constant | There are both practical and theoretical difficulties in determining h. The practical difficulties can be illustrated by the fact that the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another. The most likely reason is that the measurement uncertainty... | Which method is at fault or the discrepancy? | {
"text": [
"there is no indication which method is at fault"
],
"answer_start": [
468
]
} |
572971e61d04691400779473 | Planck_constant | The theoretical difficulties arise from the fact that all of the methods except the X-ray crystal density method rely on the theoretical basis of the Josephson effect and the quantum Hall effect. If these theories are slightly inaccurate – though there is no evidence at present to suggest they are – the methods would n... | Other than the X-ray crystal density method, other methods rely on what two effects? | {
"text": [
"the Josephson effect and the quantum Hall effect"
],
"answer_start": [
146
]
} |
572971e61d04691400779474 | Planck_constant | The theoretical difficulties arise from the fact that all of the methods except the X-ray crystal density method rely on the theoretical basis of the Josephson effect and the quantum Hall effect. If these theories are slightly inaccurate – though there is no evidence at present to suggest they are – the methods would n... | Why does relying on these effects create concern? | {
"text": [
"If these theories are slightly inaccurate"
],
"answer_start": [
196
]
} |
572971e61d04691400779475 | Planck_constant | The theoretical difficulties arise from the fact that all of the methods except the X-ray crystal density method rely on the theoretical basis of the Josephson effect and the quantum Hall effect. If these theories are slightly inaccurate – though there is no evidence at present to suggest they are – the methods would n... | Using Planck constant values from these effects would lead to what logical issue? | {
"text": [
"a circular argument"
],
"answer_start": [
503
]
} |
5729724c1d04691400779487 | Planck_constant | A watt balance is an instrument for comparing two powers, one of which is measured in SI watts and the other of which is measured in conventional electrical units. From the definition of the conventional watt W90, this gives a measure of the product KJ2RK in SI units, where RK is the von Klitzing constant which appears... | If the effects are valid, for RK = n/e2, what is the measurement of KJ2RK equal to? | {
"text": [
"the Planck constant"
],
"answer_start": [
539
]
} |
572973313f37b319004783f3 | Planck_constant | The gyromagnetic ratio γ is the constant of proportionality between the frequency ν of nuclear magnetic resonance (or electron paramagnetic resonance for electrons) and the applied magnetic field B: ν = γB. It is difficult to measure gyromagnetic ratios precisely because of the difficulties in precisely measuring B, bu... | The gyromagnetic ratio is the constant proportion between the magentic field and what? | {
"text": [
"the frequency ν of nuclear magnetic resonance"
],
"answer_start": [
68
]
} |
572973313f37b319004783f6 | Planck_constant | The gyromagnetic ratio γ is the constant of proportionality between the frequency ν of nuclear magnetic resonance (or electron paramagnetic resonance for electrons) and the applied magnetic field B: ν = γB. It is difficult to measure gyromagnetic ratios precisely because of the difficulties in precisely measuring B, bu... | The gyromagnetic ratio is often difficult to determine due to difficulty accurately determining the value of what? | {
"text": [
"the applied magnetic field B"
],
"answer_start": [
169
]
} |
572973b56aef051400154f02 | Planck_constant | A further complication is that the measurement of γ′p involves the measurement of an electric current: this is invariably measured in conventional amperes rather than in SI amperes, so a conversion factor is required. The symbol Γ′p-90 is used for the measured gyromagnetic ratio using conventional electrical units. In ... | How many methods of measuring the gyromagnetic ratio are there? | {
"text": [
"there are two methods of measuring the value"
],
"answer_start": [
330
]
} |
572973b56aef051400154f03 | Planck_constant | A further complication is that the measurement of γ′p involves the measurement of an electric current: this is invariably measured in conventional amperes rather than in SI amperes, so a conversion factor is required. The symbol Γ′p-90 is used for the measured gyromagnetic ratio using conventional electrical units. In ... | How do conversion factors compare in "low-field" and "high-field" methods of measuring the gyromagnetic ratio? | {
"text": [
"the conversion factors are different in the two cases"
],
"answer_start": [
428
]
} |
572974216aef051400154f14 | Planck_constant | The Faraday constant F is the charge of one mole of electrons, equal to the Avogadro constant NA multiplied by the elementary charge e. It can be determined by careful electrolysis experiments, measuring the amount of silver dissolved from an electrode in a given time and for a given electric current. In practice, it i... | What is the Faraday constant? | {
"text": [
"the charge of one mole of electrons"
],
"answer_start": [
26
]
} |
572974216aef051400154f17 | Planck_constant | The Faraday constant F is the charge of one mole of electrons, equal to the Avogadro constant NA multiplied by the elementary charge e. It can be determined by careful electrolysis experiments, measuring the amount of silver dissolved from an electrode in a given time and for a given electric current. In practice, it i... | How is the Farday constant value quickly calculated? | {
"text": [
"the Avogadro constant NA multiplied by the elementary charge e"
],
"answer_start": [
72
]
} |
572975206aef051400154f2e | Planck_constant | The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X... | What is the primary method for determining the Avogadro constant? | {
"text": [
"The X-ray crystal density method"
],
"answer_start": [
0
]
} |
572975206aef051400154f30 | Planck_constant | The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X... | What element is used typically to establish Avogadro's constant? | {
"text": [
"Crystals of silicon"
],
"answer_start": [
381
]
} |
57297608af94a219006aa473 | Planck_constant | There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed f... | What measurement is deemed most important to redefine in terms of physical constants? | {
"text": [
"the kilogram"
],
"answer_start": [
278
]
} |
57297608af94a219006aa474 | Planck_constant | There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed f... | What is the shape of the object that establishes the base unit of the kilogram? | {
"text": [
"cylinder"
],
"answer_start": [
371
]
} |
57297608af94a219006aa475 | Planck_constant | There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed f... | What alloy is the base unit of the kilogram made from? | {
"text": [
"platinum–iridium"
],
"answer_start": [
383
]
} |
57297608af94a219006aa476 | Planck_constant | There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed f... | Where is the base unit for the kilogram kept? | {
"text": [
"in a vault just outside Paris"
],
"answer_start": [
411
]
} |
572976ac3f37b31900478449 | Planck_constant | The legal process to change the definition of the kilogram is already underway, but it had been decided that no final decision would be made before the next meeting of the General Conference on Weights and Measures in 2011. (For more detailed information, see kilogram definitions.) The Planck constant is a leading cont... | Where would the decision to change the definition of the kilogram have occured at the earliest? | {
"text": [
"the General Conference on Weights and Measures in 2011"
],
"answer_start": [
168
]
} |
572976ac3f37b3190047844b | Planck_constant | The legal process to change the definition of the kilogram is already underway, but it had been decided that no final decision would be made before the next meeting of the General Conference on Weights and Measures in 2011. (For more detailed information, see kilogram definitions.) The Planck constant is a leading cont... | The mass of a resting body with what energy would be equal to a kilogram? | {
"text": [
"7050135639273999999♠135639274×1042 Hz"
],
"answer_start": [
533
]
} |
572976ac3f37b3190047844c | Planck_constant | The legal process to change the definition of the kilogram is already underway, but it had been decided that no final decision would be made before the next meeting of the General Conference on Weights and Measures in 2011. (For more detailed information, see kilogram definitions.) The Planck constant is a leading cont... | A kilogram could be definined as having a Planck constant of what value? | {
"text": [
"6966662606895999999♠6.62606896×10−34 J⋅s"
],
"answer_start": [
643
]
} |
57293ad06aef051400154ba8 | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | What drives the wider acceptance of renewable energy technologies? | {
"text": [
"Public policy and political leadership"
],
"answer_start": [
0
]
} |
57293ad06aef051400154ba9 | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | Denmark has a committment to 100 percent renewable energy by what year? | {
"text": [
"2050"
],
"answer_start": [
456
]
} |
57293ad06aef051400154baa | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | How many countries now have renewable energy policies? | {
"text": [
"144"
],
"answer_start": [
476
]
} |
57293b691d0469140077918d | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | How much was the total investment in renewable energy in 2012? | {
"text": [
"$244 billion"
],
"answer_start": [
83
]
} |
57293b691d0469140077918e | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | Why did the total investment in renewable energy go down in 2012? | {
"text": [
"dramatically lower solar prices"
],
"answer_start": [
138
]
} |
57293b691d0469140077918f | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | What six were the top countries for investment in recent years? | {
"text": [
"China, Germany, Spain, the United States, Italy, and Brazil"
],
"answer_start": [
365
]
} |
57293c241d046914007791a9 | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | Who has shown support for ambitious renewable energy goals? | {
"text": [
"EU member countries"
],
"answer_start": [
0
]
} |
57293c241d046914007791aa | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | What group polled the 27 EU member states in 2010? | {
"text": [
"Eurobarometer"
],
"answer_start": [
86
]
} |
57293c241d046914007791ab | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | The goal was to increase the share of renewable energy in the EU by 20 percent in what year? | {
"text": [
"2020"
],
"answer_start": [
228
]
} |
57293d583f37b3190047816d | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | By the end of 2011, total renewable power capacity worldwide exceeded what number? | {
"text": [
"1,360 GW"
],
"answer_start": [
70
]
} |
57293d583f37b3190047816e | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | Renewables contributed what percentage to our energy consumption? | {
"text": [
"19 percent"
],
"answer_start": [
322
]
} |
57293d583f37b3190047816f | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | Renewables contributed what percentage to our electricity generation? | {
"text": [
"22 percent"
],
"answer_start": [
363
]
} |
57293ff51d046914007791f3 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Who was the UN under-secretary in 2011? | {
"text": [
"Achim Steiner"
],
"answer_start": [
192
]
} |
57293ff51d046914007791f4 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Between what years did worldwide renewable energy capacity grow at rates of 10 to 60 percent annually? | {
"text": [
"2004 through 2009"
],
"answer_start": [
38
]
} |
57293ff51d046914007791f5 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Who is Achim Steiner? | {
"text": [
"UN under-secretary general"
],
"answer_start": [
165
]
} |
572941266aef051400154c0a | Renewable_energy_commercialization | According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's dem... | Which group projected that solar plant may produce most of the world's electricity within 50 years? | {
"text": [
"International Energy Agency"
],
"answer_start": [
38
]
} |
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