16 ms·

The Ultraviolet Myth

211 points by Luc 3y ago

poulpy123 3y ago
[flagged]
- deleted 3y ago
  [deleted]
tremarley 3y ago
Quantum physics: where the only certainty is that even scientists are uncertain, but don't worry, nobody understands it, not even the scientists themselves!
- zamadatix 3y ago
  This is about misunderstanding purely of history, the actual derived physics are not mistaken in either version of the tale.
- astrange 3y ago
  Quantum physics (QFT) is just about the most proven thing there is. Physics has the opposite problem - they know it's wrong but they can't find a way to disprove it. It's too good.
alecst 3y ago
It's so interesting. This isn't the only paper written about this, because I actually came across this same idea last month in a much older paper. Here's an extract from it: > It might have been thought, by some scientists in the 1890's, that refined mathematical analysis of this kind would play a role in resolving the fundamental problems of classical physics associated with the apparent failures of the equipartition theorem. But that is not what happened. > Although the quantum hypothesis did dispose of the paradox of specific heats of polyatomic gases, and eliminated the possibility that ether-vibrations (having an infinite number of degrees of freedom) would drain an indefinite amount of energy out of material systems at any finite temperature, these were not the anomalies that provoked the introduction of the quantum hypothesis in the first place. Max Planck was not one of the physicists who worried about the validity of the equipartition theorem before 1900, and the myth that his distribution law for blackbody radiation was concocted merely to escape from an "ultraviolet catastrophe" predicted by the Rayleigh-Jeans law has now been thoroughly demolished. It was Paul Ehrenfest who invented the ultraviolet catastrophe (eleven years after the publication of Rayleigh's and Planck's papers in 1900) in order to dramatize what would have been the consequences of the equipartition theorem if it had been valid for all classical dynamical systems (though neither Rayleigh nor Planck believed that it was). I have this saved as a note, but can't find the exact source atm. Here's another source though, from the 60s: https://sci-hub.ru/https://doi.org/10.1007/BF00327765 https://sci-hub.ru/https://doi.org/10.1007/BF00327765
- crdrost 3y ago
  I would be very interested to read this. I found one comment in the abstract a little bit off-putting: > Planck did not consider this a quantization, but merely a mathematical trick to be able to calculate the entropy of the oscillators. My understanding was that Planck absolutely understood that his approach would have been a mathematical trick if he took the limit h → 0, but that in stopping at a nonzero small number he was explicitly aware that he was saying something peculiar about the energies in the system, and had strayed far away from that realm of pure mathematics into something that we would today effortlessly identify as quantum, even if that word did not exist at the time.
  - lumost 3y ago
    Often, when inventing something new - it can be difficult to assess how novel the "new" thing is. Particularly when there isn't yet a word for it. Planck may have simply believed that this hinted towards something equivalent of an "atom" of light. Atom's were after all a relatively recent discovery in 1827, why couldn't you have an atom-like construct for light? and why would light atoms be any different regular atoms? While we now know a great deal about this topic - placing such speculation in a paper would be problematic. Hypothesizing that such quantizations are common for other quantities would be even more problematic. EDIT: Removed eroneous mention of michelson-moorly instead of milikan oil drop experiment.
    - DiogenesKynikos 3y ago
      I think you mean the Millikan oil drop experiment.
      - tangj 3y ago
        ... Since Michelson-Morley was supposed to show the relative speed of the Earth through the ether, but instead showed there was no ether at all.
      - lumost 3y ago
        :doh: good catch :facepalm: it's been too long since physics undergrad.
btilly 3y ago
Yet another example where it is tempting to retrofit a modern understanding onto a historical debate. We're tempted to do this because when you're embedded to the modern worldview, it is hard to remember that others were once possible. And it is tempting to believe that history was a straight arrow to modern truths. In fact it was seldom such a straight path. Kuhn complained about this in The Structure of Scientific Revolutions. When trying to teach the history of science to scientists, you have to work to get them to stop trying to think the "correct" way, so that they can understand the actual historical debate.
- bee_rider 3y ago
  I wonder if it might be pop-sci vs science, rather than modern vs historical. Physicists (from the outside at least) have always seemed more like hunters than the town watch, they go looking for the problems. There isn’t some catastrophic looming threat of physics approaching that they have to deal with, haha. Unexplainable data is an opportunity and all that.
  - btilly 3y ago
    What I'm talking about is very much modern vs historical. To take a trivial example, most of us would like to draw a straight line from Darwin writing The Origin of the Species to the current acceptance of his theory of evolution. We have no particular desire to follow how Darwin's work inspired Francis Galton to study heredity. Unfortunately Galton discovered regression to the mean when he did. Further experiments undermined Darwin's theories as it uncovered evidence for "natural types". The result was that a half-century after Darwin's great book, many scientists doubted Darwin's theories. But then R. A. Fischer managed to explain the mess with population genetics based on Mendel's theories. "Natural types" disappeared from the literature, and Darwin was back. Today Galton is likely to be remembered as a dilletante who invented the idea of eugenics. And Fischer as a genius in statistics. We retrofit a story with heroes (Darwin and Fischer) and villains (Galton). We skip over the bad parts, and focus on the good. In the process we forget that Darwin also took it for granted that blacks must be inferior to whites. And that Fischer was also a supporter of eugenics. And that Galton set out to confirm Darwin, then accepted the data that he encountered. We want a story, not a mess. But history is full of messes. Arranging the right ideas in the right ways involved a whole lot of trial and error that wasn't obvious at the time. While some of us enjoy learning about the history, it actually isn't very helpful for scientists. Because there is little point in learning every wrong idea that people used to hold, only to immediately learn that you can forget it again because it was wrong. But while that exercise does not help us learn what is currently known, maybe it can help give us more humility about what it is we think we know today?
sgdpk 3y ago
To be fair, I was taught exactly what this paper claims in my Physics degree. Although I was also taught what they call the "myth" in other classes.
- pdonis 3y ago
  I was never taught the myth in an actual class. Every time I have seen it has been in the context of a pop science article or book.
  - Sesse__ 3y ago
    Seemingly also the Wikipedia article (https://en.wikipedia.org/wiki/Ultraviolet_catastrophe https://en.wikipedia.org/wiki/Ultraviolet_catastrophe) claims the pop-sci ordering: “As the theory diverged from empirical observations when these frequencies reached the ultraviolet region of the electromagnetic spectrum, there was a problem.[3] This problem was later found to be due to a property of quanta as proposed by Max Planck: There could be no fraction of a discrete energy package already carrying minimal energy.”
- josh-sematic 3y ago
  Agreed; my professors did use Planck's trick to introduce quantization, but made it very clear that he was just fitting the data and thought the discretization would disappear with further analysis.
adtac 3y ago
Douglas Hofstader has a talk on this topic called "Albert Einstein on Light; Light on Albert Einstein" that I often revisit: https://www.youtube.com/watch?v=ePA1zq56J1I https://www.youtube.com/watch?v=ePA1zq56J1I (watch 10:30 to 12:00 if you're pressed for time, but I recommend the whole thing)
- agonz253 3y ago
  Indeed. I recommend also checking out the 2nd volume of Einstein's collected papers. There is one with the proceedings from a conference on the subject, and Einstein is basically alone in trying to convince his peers, including Planck, of the reality of "quanta" of light, independent of the process of emission and absorption or mathematical tricks.
- djmips 3y ago
  Thanks. Watching NOW.
fsmv 3y ago
This video talks about this story and in particular acknowledges that it was called the ultraviolet catastrophe after Plank https://youtu.be/gXeAp_lyj9s https://youtu.be/gXeAp_lyj9s
- DrDroop 3y ago
  I wanted to post the same thing, quiet a coincidence I watched it yesterday.
  - SKCarr 3y ago
    Seems to have come out one day before this paper was submitted, which is quite a coincidence.
csours 3y ago
In which a more satisfying story "beats" the messiness of true history.
bjornsing 3y ago
I have a masters degree in physics from a Swedish university, and I don’t think I’ve ever heard the “myth”. But the actual story as described in the paper is vaguely familiar. Before reading it my mind wandered to Einstein and quantization of light. Is this mainly a US myth perhaps?
- pif 3y ago
  Same here, Italian background.
- bowsamic 3y ago
  We were taught this myth in the UK EDIT: both at high school and across multiple different lecturers at university
- bananskalhalk 3y ago
  I was taught this in a Swedish high school and it was repeated at a Swedish university one year later.
  - BoardsOfCanada 3y ago
    Same here as for at Swe university
  - bananskalhalk 3y ago
    Added: Please not that the authors are Norwegian at a Norwegian university, and the first citation are "KVANTEFYSIKKENS UTVIKLING i fysikklærebøker, vitenskapshistorien og undervisning" by Reidun Renstrøm at the University of Oslo, all proclaiming the myth being perversive. I would be careful proclaiming this being some kind of American phenomenon.
- BeetleB 3y ago
  Same here. Studied it in 2 different countries, and it was always presented as "trying to explain black body radiation". I think UV catastrophe was merely mentioned as a side note.
- 3y ago
prof-dr-ir 3y ago
This paper is nice but appears to stretch its result quite a bit. First, the authors make a general claim about "most physics textbooks" without providing a single example. I think one will often encounter more nuanced statements in the better and more widely used textbooks. And I think the paper sorely lacks evidence for the general claim in the concluding sentence: "The idea that physics progress through a series of crisis, is hard to defend." Not only do they present only a single example, but even in that case one could claim that the "crisis" started after the discovery of Planck's formula! After all, it fitted the data supremely well but required this mystery constant: h. It took physicist a quarter century to resolve the deeper meaning of Planck's constant. If that was not a crisis in physics then I do not know what would qualify as one.
- alacritas0 3y ago
  i wouldn’t consider a quarter century of work by the field a crisis
- littlestymaar 3y ago
  > to defend." Not only do they present only a single example Really? When there Mercury's perihelion mystery at the exact same period? (Which got us general relativity)
- alecst 3y ago
  It's not a stretch at all in my opinion, not only was I taught this myself (multiple times at two separate universities in the US) but there was a paper addressing this myth as far back as the 60s. Though I do agree with your second point. I can name two crises off the top of my head: the black hole information paradox, and the galaxy rotation curves which some claim are due to dark matter. One is a major theoretical problem, and the other is a major experimental problem. And though crises they may be, it's not like people are running around with their hair on fire.
  - d0mine 3y ago
    There is a crisis in cosmology right now e.g., the apparent conflict in our measurements of the expansion rate of the early versus the modern universe. https://youtube.com/playlist?list=PLd19WvC9yqUf5TRqYoMYxEwjT6JIDW4Zn https://youtube.com/playlist?list=PLd19WvC9yqUf5TRqYoMYxEwjT...
adrian_b 3y ago
Besides the myth busted in this paper, that the actually later work of Rayleigh could have influenced Planck, there is another incorrect myth, that Planck has introduced the "constant of Planck" in his publication from 1900, where he presented the deduction of the Planck formula from the supposition that the emission and absorption of electromagnetic radiation are quantized. This frequently seen claim is also wrong. Planck has introduced the constant of Planck and he has also computed its value with excellent precision for that time (4% relative error) in an earlier work published in 1899: Max Planck, "Ueber irreversible Strahlungsvorgaenge", "Sitzungsberichte der koeniglich preussischen Akademie der Wissenschaften zu Berlin. Jahrgang 1899", pp. 440-480. There Max Planck has presented deductions of the formulae previously established by Wien for the blackbody radiation, where he replaced the empirical constants of Wien with functions of other universal constants and of the new universal constant introduced by him. Already Maxwell, a quarter of century earlier, had shown that it is possible to determine the units for all physical quantities with a single arbitrary choice (in his example, the wavelength of the yellow light emitted by sodium vapor). In 1899, Planck has shown that the law of blackbody radiation provides an additional relationship between the units of length, time and energy, which, together with the previous relationships considered by Maxwell, can determine the units of all physical quantities without any arbitrary choice. So at the end of this work from 1899, where the constant of Planck has been introduced, he has also presented the system of natural units known now as the Planck units. Nevertheless, the system of Planck units cannot be used as the base of a practical system of units, because the uncertainty of measuring the Newtonian constant of gravitation is huge. This makes useless one of the equations that connect the units of length, time and energy. Because of that, any practical system of units must contain a single arbitrary choice of a unit, which in the case of SI is the frequency of a certain hyperfine transition of the cesium-133 atom, while all the other units result from this choice by adopting conventional values for the universal constants, except for the Newtonian constant of gravitation, which must be measured experimentally (some constant determining the intensity of the electromagnetic interaction, e.g. the fine structure constant, must also be measured experimentally, but for that the uncertainty is extremely low). BTW, another extremely frequent incorrect claim about the constant of Planck is that it is a quantum of action. This is very wrong, it is a quantum of angular momentum (the ratio between energy and frequency is an angular momentum, like also the ratio between their integrals, i.e. between action and plane angle). The origin of the mistake is the fact that many follow the suggestions of the recent SI brochures (there was a resolution adopted by vote that the unit of plane angle is not a base unit, which is equivalent with establishing by vote that 2 + 2 = 5), and they omit the unit of plane angle in the dimensional formulae, in which case it appears that the unit of action is the same with the unit of angular momentum, but they are not the same, as any attempt to change the unit used for plane angles would demonstrate, e.g. between radians and degrees or cycles. The original constant of Planck corresponds to plane angles measured in cycles, while the so-called h bar is the same constant converted to correspond with plane angles measured in radians.
sho_hn 3y ago
As a physics layman, I learned his part of history from the book "Quantum" by Manjit Kumar, which as far as I can tell got the Planck bit right and covered his black body work correctly, FWIW. It was a good read.
kazinator 3y ago
> many of the stories that have become central to the physics lore are mere pseudo-histories far detached from the real events But, like, you know how Newton discovered gravity when an apple fell on his head? Totally true, pinky swear!
demondemidi 3y ago
Funny I spent Sunday afternoon watching youtubers talk about this and they all pretty much said that the catastrophe predated Plank's corrections (or caused them). Is this wrong, or is it just pedantic? Most importantly, is the wikipedia page correct: https://en.wikipedia.org/wiki/Ultraviolet_catastrophe https://en.wikipedia.org/wiki/Ultraviolet_catastrophe
lowbloodsugar 3y ago
Never heard of this, despite a physics degree. Is this what happens after social media is invented and all sorts of bullshit is spread as fact?
- wiml 3y ago
  No, I was taught this at least twice before social media became a thing.
mcnamaratw 3y ago
https://en.wikipedia.org/wiki/Rayleigh–Jeans_law https://en.wikipedia.org/wiki/Rayleigh–Jeans_law
photochemsyn 3y ago
Pedagogically, this is an argument against teaching physics using the historical development model. You end up with post hoc arguments and simplified narratives, and I think it it just makes life harder for undergraduate students. Maybe 'history of science' should be its own subject? Some textbooks (e.g. Molecular Quantum Mechanics, Atkins & Friedman) take a more nuanced view. They present failures of classical calculations of the heat capacity of solids near absolute zero side by side with blackbody radiation: > "Einstein recognized the similarity between this problem and black-body radiation, for if each atomic oscillator required a certain minimum energy before it would actively oscillate, then at low temperatures some would be inactive and the heat capacity would be smaller than expected." Debye improved the theory by allowing atoms to oscillate with different frequencies. So looking back, one can say matter appears to be quantized, and this shows up at low temperatures, and radiation appears to be quantized, and this shows up at high frequencies - which is a nice symmetric argument, visible in hindsight, that probably helps students grasp the concept of the quantized harmonic oscillator (and why they need to learn about it). One major development was Bose deriving Planck's radiation law using quantum statisical arguments (and no classical physics), with further development by Einstein c. 1924 - but this might be a difficult place to start from, teaching-wise. https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_statistics https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_statisti...
stracer 3y ago
This particular part of "physicist's history of physics" about quantization and Planck's work, promulgated by some sources, is well-known to be a false account of history and motivations, and has been criticized in mainstream literature before, e.g. by Helge Kragh [1] (and probably by many others). The present authors apparently are not aware of this, which makes me suspicious that they did not do their homework on this topic... [1] https://dept.math.lsa.umich.edu/~krasny/math156_article_planck.pdf https://dept.math.lsa.umich.edu/~krasny/math156_article_plan...
- djmips 3y ago
  Maybe, maybe not but the false account continues to be propagated.
lewtun 3y ago
The myth is also promoted in Chapter 3 of The Making of the Atomic Bomb by Richard Rhodes: > Plank had taught at Berlin since 1889. In 1900 he had proposed a revolutionary idea to explain a persistent problem in mechanical physics, the so-called ultraviolet catastrophe
Danielben 3y ago
[flagged]
pbj1968 3y ago
The Planck institute sent some borderline animal to my city where he proceeded to criticize everything and everyone he saw. He directed some blah blah department under their purview. Completely unimpressed here.

211 points by Luc 3y ago

poulpy123 3y ago

[flagged]

deleted 3y ago
[deleted]

tremarley 3y ago

Quantum physics: where the only certainty is that even scientists are uncertain, but don't worry, nobody understands it, not even the scientists themselves!

zamadatix 3y ago
This is about misunderstanding purely of history, the actual derived physics are not mistaken in either version of the tale.
astrange 3y ago
Quantum physics (QFT) is just about the most proven thing there is. Physics has the opposite problem - they know it's wrong but they can't find a way to disprove it. It's too good.

alecst 3y ago

It's so interesting. This isn't the only paper written about this, because I actually came across this same idea last month in a much older paper. Here's an extract from it: > It might have been thought, by some scientists in the 1890's, that refined mathematical analysis of this kind would play a role in resolving the fundamental problems of classical physics associated with the apparent failures of the equipartition theorem. But that is not what happened. > Although the quantum hypothesis did dispose of the paradox of specific heats of polyatomic gases, and eliminated the possibility that ether-vibrations (having an infinite number of degrees of freedom) would drain an indefinite amount of energy out of material systems at any finite temperature, these were not the anomalies that provoked the introduction of the quantum hypothesis in the first place. Max Planck was not one of the physicists who worried about the validity of the equipartition theorem before 1900, and the myth that his distribution law for blackbody radiation was concocted merely to escape from an "ultraviolet catastrophe" predicted by the Rayleigh-Jeans law has now been thoroughly demolished. It was Paul Ehrenfest who invented the ultraviolet catastrophe (eleven years after the publication of Rayleigh's and Planck's papers in 1900) in order to dramatize what would have been the consequences of the equipartition theorem if it had been valid for all classical dynamical systems (though neither Rayleigh nor Planck believed that it was). I have this saved as a note, but can't find the exact source atm. Here's another source though, from the 60s: https://sci-hub.ru/https://doi.org/10.1007/BF00327765 https://sci-hub.ru/https://doi.org/10.1007/BF00327765

crdrost 3y ago
I would be very interested to read this. I found one comment in the abstract a little bit off-putting: > Planck did not consider this a quantization, but merely a mathematical trick to be able to calculate the entropy of the oscillators. My understanding was that Planck absolutely understood that his approach would have been a mathematical trick if he took the limit h → 0, but that in stopping at a nonzero small number he was explicitly aware that he was saying something peculiar about the energies in the system, and had strayed far away from that realm of pure mathematics into something that we would today effortlessly identify as quantum, even if that word did not exist at the time.
- lumost 3y ago
  Often, when inventing something new - it can be difficult to assess how novel the "new" thing is. Particularly when there isn't yet a word for it. Planck may have simply believed that this hinted towards something equivalent of an "atom" of light. Atom's were after all a relatively recent discovery in 1827, why couldn't you have an atom-like construct for light? and why would light atoms be any different regular atoms? While we now know a great deal about this topic - placing such speculation in a paper would be problematic. Hypothesizing that such quantizations are common for other quantities would be even more problematic. EDIT: Removed eroneous mention of michelson-moorly instead of milikan oil drop experiment.
  - DiogenesKynikos 3y ago
    I think you mean the Millikan oil drop experiment.
    - tangj 3y ago
      ... Since Michelson-Morley was supposed to show the relative speed of the Earth through the ether, but instead showed there was no ether at all.
    - lumost 3y ago
      :doh: good catch :facepalm: it's been too long since physics undergrad.

btilly 3y ago

Yet another example where it is tempting to retrofit a modern understanding onto a historical debate. We're tempted to do this because when you're embedded to the modern worldview, it is hard to remember that others were once possible. And it is tempting to believe that history was a straight arrow to modern truths. In fact it was seldom such a straight path. Kuhn complained about this in The Structure of Scientific Revolutions. When trying to teach the history of science to scientists, you have to work to get them to stop trying to think the "correct" way, so that they can understand the actual historical debate.

bee_rider 3y ago
I wonder if it might be pop-sci vs science, rather than modern vs historical. Physicists (from the outside at least) have always seemed more like hunters than the town watch, they go looking for the problems. There isn’t some catastrophic looming threat of physics approaching that they have to deal with, haha. Unexplainable data is an opportunity and all that.
- btilly 3y ago
  What I'm talking about is very much modern vs historical. To take a trivial example, most of us would like to draw a straight line from Darwin writing The Origin of the Species to the current acceptance of his theory of evolution. We have no particular desire to follow how Darwin's work inspired Francis Galton to study heredity. Unfortunately Galton discovered regression to the mean when he did. Further experiments undermined Darwin's theories as it uncovered evidence for "natural types". The result was that a half-century after Darwin's great book, many scientists doubted Darwin's theories. But then R. A. Fischer managed to explain the mess with population genetics based on Mendel's theories. "Natural types" disappeared from the literature, and Darwin was back. Today Galton is likely to be remembered as a dilletante who invented the idea of eugenics. And Fischer as a genius in statistics. We retrofit a story with heroes (Darwin and Fischer) and villains (Galton). We skip over the bad parts, and focus on the good. In the process we forget that Darwin also took it for granted that blacks must be inferior to whites. And that Fischer was also a supporter of eugenics. And that Galton set out to confirm Darwin, then accepted the data that he encountered. We want a story, not a mess. But history is full of messes. Arranging the right ideas in the right ways involved a whole lot of trial and error that wasn't obvious at the time. While some of us enjoy learning about the history, it actually isn't very helpful for scientists. Because there is little point in learning every wrong idea that people used to hold, only to immediately learn that you can forget it again because it was wrong. But while that exercise does not help us learn what is currently known, maybe it can help give us more humility about what it is we think we know today?

sgdpk 3y ago

To be fair, I was taught exactly what this paper claims in my Physics degree. Although I was also taught what they call the "myth" in other classes.

pdonis 3y ago
I was never taught the myth in an actual class. Every time I have seen it has been in the context of a pop science article or book.
- Sesse__ 3y ago
  Seemingly also the Wikipedia article (https://en.wikipedia.org/wiki/Ultraviolet_catastrophe https://en.wikipedia.org/wiki/Ultraviolet_catastrophe) claims the pop-sci ordering: “As the theory diverged from empirical observations when these frequencies reached the ultraviolet region of the electromagnetic spectrum, there was a problem.[3] This problem was later found to be due to a property of quanta as proposed by Max Planck: There could be no fraction of a discrete energy package already carrying minimal energy.”
josh-sematic 3y ago
Agreed; my professors did use Planck's trick to introduce quantization, but made it very clear that he was just fitting the data and thought the discretization would disappear with further analysis.

adtac 3y ago

Douglas Hofstader has a talk on this topic called "Albert Einstein on Light; Light on Albert Einstein" that I often revisit: https://www.youtube.com/watch?v=ePA1zq56J1I https://www.youtube.com/watch?v=ePA1zq56J1I (watch 10:30 to 12:00 if you're pressed for time, but I recommend the whole thing)

agonz253 3y ago
Indeed. I recommend also checking out the 2nd volume of Einstein's collected papers. There is one with the proceedings from a conference on the subject, and Einstein is basically alone in trying to convince his peers, including Planck, of the reality of "quanta" of light, independent of the process of emission and absorption or mathematical tricks.
djmips 3y ago
Thanks. Watching NOW.

fsmv 3y ago

This video talks about this story and in particular acknowledges that it was called the ultraviolet catastrophe after Plank https://youtu.be/gXeAp_lyj9s https://youtu.be/gXeAp_lyj9s

DrDroop 3y ago
I wanted to post the same thing, quiet a coincidence I watched it yesterday.
- SKCarr 3y ago
  Seems to have come out one day before this paper was submitted, which is quite a coincidence.

csours 3y ago

In which a more satisfying story "beats" the messiness of true history.

bjornsing 3y ago

I have a masters degree in physics from a Swedish university, and I don’t think I’ve ever heard the “myth”. But the actual story as described in the paper is vaguely familiar. Before reading it my mind wandered to Einstein and quantization of light. Is this mainly a US myth perhaps?

pif 3y ago
Same here, Italian background.
bowsamic 3y ago
We were taught this myth in the UK EDIT: both at high school and across multiple different lecturers at university
bananskalhalk 3y ago
I was taught this in a Swedish high school and it was repeated at a Swedish university one year later.
- BoardsOfCanada 3y ago
  Same here as for at Swe university
- bananskalhalk 3y ago
  Added: Please not that the authors are Norwegian at a Norwegian university, and the first citation are "KVANTEFYSIKKENS UTVIKLING i fysikklærebøker, vitenskapshistorien og undervisning" by Reidun Renstrøm at the University of Oslo, all proclaiming the myth being perversive. I would be careful proclaiming this being some kind of American phenomenon.
BeetleB 3y ago
Same here. Studied it in 2 different countries, and it was always presented as "trying to explain black body radiation". I think UV catastrophe was merely mentioned as a side note.
3y ago

prof-dr-ir 3y ago

This paper is nice but appears to stretch its result quite a bit. First, the authors make a general claim about "most physics textbooks" without providing a single example. I think one will often encounter more nuanced statements in the better and more widely used textbooks. And I think the paper sorely lacks evidence for the general claim in the concluding sentence: "The idea that physics progress through a series of crisis, is hard to defend." Not only do they present only a single example, but even in that case one could claim that the "crisis" started after the discovery of Planck's formula! After all, it fitted the data supremely well but required this mystery constant: h. It took physicist a quarter century to resolve the deeper meaning of Planck's constant. If that was not a crisis in physics then I do not know what would qualify as one.

alacritas0 3y ago
i wouldn’t consider a quarter century of work by the field a crisis
littlestymaar 3y ago
> to defend." Not only do they present only a single example Really? When there Mercury's perihelion mystery at the exact same period? (Which got us general relativity)
alecst 3y ago
It's not a stretch at all in my opinion, not only was I taught this myself (multiple times at two separate universities in the US) but there was a paper addressing this myth as far back as the 60s. Though I do agree with your second point. I can name two crises off the top of my head: the black hole information paradox, and the galaxy rotation curves which some claim are due to dark matter. One is a major theoretical problem, and the other is a major experimental problem. And though crises they may be, it's not like people are running around with their hair on fire.
- d0mine 3y ago
  There is a crisis in cosmology right now e.g., the apparent conflict in our measurements of the expansion rate of the early versus the modern universe. https://youtube.com/playlist?list=PLd19WvC9yqUf5TRqYoMYxEwjT6JIDW4Zn https://youtube.com/playlist?list=PLd19WvC9yqUf5TRqYoMYxEwjT...

adrian_b 3y ago

Besides the myth busted in this paper, that the actually later work of Rayleigh could have influenced Planck, there is another incorrect myth, that Planck has introduced the "constant of Planck" in his publication from 1900, where he presented the deduction of the Planck formula from the supposition that the emission and absorption of electromagnetic radiation are quantized. This frequently seen claim is also wrong. Planck has introduced the constant of Planck and he has also computed its value with excellent precision for that time (4% relative error) in an earlier work published in 1899: Max Planck, "Ueber irreversible Strahlungsvorgaenge", "Sitzungsberichte der koeniglich preussischen Akademie der Wissenschaften zu Berlin. Jahrgang 1899", pp. 440-480. There Max Planck has presented deductions of the formulae previously established by Wien for the blackbody radiation, where he replaced the empirical constants of Wien with functions of other universal constants and of the new universal constant introduced by him. Already Maxwell, a quarter of century earlier, had shown that it is possible to determine the units for all physical quantities with a single arbitrary choice (in his example, the wavelength of the yellow light emitted by sodium vapor). In 1899, Planck has shown that the law of blackbody radiation provides an additional relationship between the units of length, time and energy, which, together with the previous relationships considered by Maxwell, can determine the units of all physical quantities without any arbitrary choice. So at the end of this work from 1899, where the constant of Planck has been introduced, he has also presented the system of natural units known now as the Planck units. Nevertheless, the system of Planck units cannot be used as the base of a practical system of units, because the uncertainty of measuring the Newtonian constant of gravitation is huge. This makes useless one of the equations that connect the units of length, time and energy. Because of that, any practical system of units must contain a single arbitrary choice of a unit, which in the case of SI is the frequency of a certain hyperfine transition of the cesium-133 atom, while all the other units result from this choice by adopting conventional values for the universal constants, except for the Newtonian constant of gravitation, which must be measured experimentally (some constant determining the intensity of the electromagnetic interaction, e.g. the fine structure constant, must also be measured experimentally, but for that the uncertainty is extremely low). BTW, another extremely frequent incorrect claim about the constant of Planck is that it is a quantum of action. This is very wrong, it is a quantum of angular momentum (the ratio between energy and frequency is an angular momentum, like also the ratio between their integrals, i.e. between action and plane angle). The origin of the mistake is the fact that many follow the suggestions of the recent SI brochures (there was a resolution adopted by vote that the unit of plane angle is not a base unit, which is equivalent with establishing by vote that 2 + 2 = 5), and they omit the unit of plane angle in the dimensional formulae, in which case it appears that the unit of action is the same with the unit of angular momentum, but they are not the same, as any attempt to change the unit used for plane angles would demonstrate, e.g. between radians and degrees or cycles. The original constant of Planck corresponds to plane angles measured in cycles, while the so-called h bar is the same constant converted to correspond with plane angles measured in radians.

sho_hn 3y ago

As a physics layman, I learned his part of history from the book "Quantum" by Manjit Kumar, which as far as I can tell got the Planck bit right and covered his black body work correctly, FWIW. It was a good read.

kazinator 3y ago

> many of the stories that have become central to the physics lore are mere pseudo-histories far detached from the real events But, like, you know how Newton discovered gravity when an apple fell on his head? Totally true, pinky swear!

demondemidi 3y ago

Funny I spent Sunday afternoon watching youtubers talk about this and they all pretty much said that the catastrophe predated Plank's corrections (or caused them). Is this wrong, or is it just pedantic? Most importantly, is the wikipedia page correct: https://en.wikipedia.org/wiki/Ultraviolet_catastrophe https://en.wikipedia.org/wiki/Ultraviolet_catastrophe

lowbloodsugar 3y ago

Never heard of this, despite a physics degree. Is this what happens after social media is invented and all sorts of bullshit is spread as fact?

wiml 3y ago
No, I was taught this at least twice before social media became a thing.

mcnamaratw 3y ago

https://en.wikipedia.org/wiki/Rayleigh–Jeans_law https://en.wikipedia.org/wiki/Rayleigh–Jeans_law

photochemsyn 3y ago

Pedagogically, this is an argument against teaching physics using the historical development model. You end up with post hoc arguments and simplified narratives, and I think it it just makes life harder for undergraduate students. Maybe 'history of science' should be its own subject? Some textbooks (e.g. Molecular Quantum Mechanics, Atkins & Friedman) take a more nuanced view. They present failures of classical calculations of the heat capacity of solids near absolute zero side by side with blackbody radiation: > "Einstein recognized the similarity between this problem and black-body radiation, for if each atomic oscillator required a certain minimum energy before it would actively oscillate, then at low temperatures some would be inactive and the heat capacity would be smaller than expected." Debye improved the theory by allowing atoms to oscillate with different frequencies. So looking back, one can say matter appears to be quantized, and this shows up at low temperatures, and radiation appears to be quantized, and this shows up at high frequencies - which is a nice symmetric argument, visible in hindsight, that probably helps students grasp the concept of the quantized harmonic oscillator (and why they need to learn about it). One major development was Bose deriving Planck's radiation law using quantum statisical arguments (and no classical physics), with further development by Einstein c. 1924 - but this might be a difficult place to start from, teaching-wise. https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_statistics https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_statisti...

stracer 3y ago

This particular part of "physicist's history of physics" about quantization and Planck's work, promulgated by some sources, is well-known to be a false account of history and motivations, and has been criticized in mainstream literature before, e.g. by Helge Kragh [1] (and probably by many others). The present authors apparently are not aware of this, which makes me suspicious that they did not do their homework on this topic... [1] https://dept.math.lsa.umich.edu/~krasny/math156_article_planck.pdf https://dept.math.lsa.umich.edu/~krasny/math156_article_plan...

djmips 3y ago
Maybe, maybe not but the false account continues to be propagated.

lewtun 3y ago

The myth is also promoted in Chapter 3 of The Making of the Atomic Bomb by Richard Rhodes: > Plank had taught at Berlin since 1889. In 1900 he had proposed a revolutionary idea to explain a persistent problem in mechanical physics, the so-called ultraviolet catastrophe

Danielben 3y ago

[flagged]

pbj1968 3y ago

The Planck institute sent some borderline animal to my city where he proceeded to criticize everything and everyone he saw. He directed some blah blah department under their purview. Completely unimpressed here.