Talk:Ultraviolet catastrophe

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Incorrect History

To all: the history presented in the previous version of this article is widely reproduced in physics textbooks, but it happens to be wrong. Historians of physics noticed this almost 50 years ago, but the textbooks just haven't caught up. I've added a link to an article in Physics World that gets it right - please look at it before reverting the article. — Preceding unsigned comment added by Rparson (talk • contribs)

In that case, you might need to clarify black body, too, since that says that the problem was solved by Planck. --Heron 21:10, 3 July 2006 (UTC)[reply]

Quote from your article (emphasis mine): "In other words, did Planck really introduce the quantum hypothesis a century ago? The historian and philosopher of science Thomas Kuhn, who carefully analysed Planck's route to the black-body radiation law and its aftermath, certainly thought Planck does not deserve the credit (see further reading). However, there is evidence both for and against Kuhn's controversial interpretation, which has been much discussed by historians of physics." It's not a clean cut case. Right now the article only reflects this one opinion and seems rather misleading. KLGerads (talk) 21:25, 29 June 2014 (UTC)[reply]

I suggest we delete the section "Incorrect History". It's confused and doesn't get the point of the article it references. "That Planck's proposal happened to provide a solution for it was realized much later, as stated above." It was immediate obvious at the time that Planck's proposal solved the problem of the ultraviolet catastrophe (which wasn't called this, at the time). But, it wasn't obvious that the energy-quanta introduced by Planck had profound consequences. In fact, it was already obvious to Wien and many others that the Rayleigh–Jeans law wasn't correct and so Wien proposed his empirical formula. Planck tried to create a theoretical theory to verify this formula. Then it was realized that Wien's forumula didn't work for low frequencies and Planck made changes to his theory and derived the now accepted Planck law. -- KLGerads (talk) 22:31, 29 June 2014 (UTC)[reply]

The Wikipedia article on equipartition theorem states: "Along with other evidence, equipartition's failure to model black-body radiation—also known as the ultraviolet catastrophe—led Max Planck to suggest that energy in the light was quantized, a revolutionary hypothesis that spurred the development of quantum mechanics and quantum field theory." —Preceding unsigned comment added by 81.159.28.144 (talk) 05:17, 31 December 2010 (UTC)[reply]

The "historical inaccuracies" sections says, "That Planck's proposal happened to provide a solution for it was realized much later, as stated above", but stated above it still says, "Max Planck solved the problem." Thirteenangrymen (talk) 11:41, 4 April 2011 (UTC)[reply]

I agree completely. Planck did not solve the ultraviolet catastrophe problem, and when Einstein published his paper that did so, Planck attacked it in the strongest terms. Basically, Unlike Einstein, Planck didn't entertain for a moment the possibility that light quanta were real physical particles. See for example: Einstein and the Quantum, A. Douglas Stone, Princeton University Press, 2013. — Preceding unsigned comment added by 208.102.195.56 (talk) 00:28, 26 June 2014 (UTC)[reply]

"Planck got very angry at this audacious paper and never forgave Einstein for writing it." I own the book that is cited as a source (Einstein and the Quantum) and I cannot find this particular part. Planck's reaction is described as follows on page 80: "Planck was known for being open to publishing scientific contributions with which he disagreed, as long as they did not contain clear errors, and this tolerance likely came into play with Einstein's paper. Planck consistently opposed the idea of the particulate nature of light in vacuum, in a respectful but firm manner, for at least a decade after its publication." Planck was one of Einstein's strongest supporters, this is very misleading. KLGerads (talk) 18:04, 29 June 2014 (UTC)[reply]

Rather than delete the section, why not rewrite it (and retitle it) to correctly represent the alternative historical views of what Planck did? Dicklyon (talk) 06:03, 30 June 2014 (UTC)[reply]

Possibly Misleading Literature

There might be a reason why, perhaps, the ultraviolet catastrophe was not mentioned in the literature, and yet was a motivation for Planck and others. First, the ultraviolet catastrophe is an obvious consequence of equipartition. It means that cavities cannot come to equilibrium in a Boltzmann distribution, and this was probably clear in the 19th century not just to Planck, but to many people. They just couldn't publish it, because the result is so obviously wrong.

Wien was able to account for most of the blackbody law with a weird hypothesis of Boltzmann suppression of high frequencies. Wien possibly didn't understand equipartition very well, because he published this crazy law. But all those other people must have understood equipartition, because they all started working on this stuff. Wien's hypothesis violates equipartition.

But his hypothesis works. They were probably all scratching their heads trying to figure out why. What exactly Wien did to get his distribution, because it certainly wasn't "right", in the sense of it wasn't the right classical answer, but it certainly matched experiment better than the nonsense classical answer.

He used adiabatic invariance to arrive at his result, but made an unjustified assumption that high frequencies were suppressed the same way high energies are. This is not true in classical mechanics, but again, it is true experimentally. Anyway, he was guessing, and he didn't guess exactly right. So Planck went and fixed his formula to interpolate with the result of classical equipartition which we now call the Rayleigh Jeans result.

This means Planck knew both results, and knew that they were inconsistent with each other. The Rayleigh-Jeans law, again, has the obvious ultraviolet catastrophy. Nobody could miss it. The distribution doesn't fall off at high frequencies. It can't be right.

Once the whole thing was sorted out, the experts began to disseminate. The first disseminations according to the article are by Einstein, Jeans, and Rayleigh. I think that they were trying to report accurately what their thinking was, that they were motivated by the obvious incompatibility of Wien's law and equipartition. I think in this case, and I never though I would say this, the history in the physics books might be right.Likebox 16:42, 14 September 2007 (UTC)[reply]

Electromagnetic Modes

Just what is meant by "electromagnetic modes" in the 2nd paragraph? C.pergiel (talk) 19:47, 31 January 2008 (UTC)[reply]

Italic text== Matter Isn't Infinitely Divisible ==

Isn't the Ultraviolet catastrophe easily explained away by the simple fact that matter isn't infinitely divisible? blackbodies dont emit radiation with infinite frequency because there are no electrons in them that are colliding an infinite number of times per sec. Lemmiwinks2 (talk) 06:39, 5 August 2009 (UTC)[reply]

This is exactly what a lot of 19th century people thought. Although matter is not infinitely divisible, light is. If what you are saying is true (and this is what Boltzmann believed: something like this, but he wasn't sure), then thermal equilibrium is impossible for light, and each system would have a different distribution of frequencies, depending on how long the light was knocking about the system, and exactly how it interacted with the electrons.

But the average frequency of the light doesn't keep going up with time, as you would expect from this idea, as the light scatters and rescatters from the electrons. Nor does it settle into a steady state which is different in different situations. Instead, you end up with a situation where the light at temperature T behaves exactly like anything else in thermal equilibrium, with a unique frequency distribution only determined by the temperature. What gives? The frequency of light at temperature T has to somehow be related to the average thermal energy, so you need a constant the converts thermal energy to frequency of light, and this is Planck's constant.Likebox (talk) 20:20, 21 September 2009 (UTC)[reply]

Thermal or Thermodynamic Equilibrium?

The first paragraph says thermal equilibrium but links to thermodynamic equilibrium. I'd change it but I don't know which is correct. :) — Preceding unsigned comment added by 94.169.126.129 (talk) 22:51, 6 February 2012 (UTC)[reply]

Lay audience

I love how the article says "That Planck's proposal happened to provide a solution for it was realized much later, as stated above.[3] Though this has been known by historians for many decades, the historically incorrect version persists, in part because Planck's actual motivations for the proposal of the quantum are complicated and difficult to summarize to a lay audience." So, it's too complicated for us proles. That's just GREAT! Can we please have a new badge "Candidate for Deletion: Too complicated." and stick it on all the function calculus pages etc. to achieve a new, improved, dumberer wikipedia? 84.134.85.149 (talk) —Preceding undated comment added 18:47, 28 May 2012 (UTC)[reply]

"...the historically incorrect version persists, in part because Planck's actual motivations for the proposal of the quantum are complicated and difficult to summarize to a lay audience." It would be great if there was perhaps a line or two to detail his actual motivations, instead of simply saying 'too complicated'. — Preceding unsigned comment added by 109.158.233.239 (talk) 21:38, 11 January 2013 (UTC)[reply]

This aspect of the article (and indeed the glancing mention the topic gets in the black body and black-body radiation articles) is wretched. Whether Kuhn's views are correct or not, there appears to be controversy; this article shouldn't be held hostage to Kuhn's views or those of his disciples. The article cries out for the attention of a sober, informed person Rt3368 (talk) 06:23, 14 September 2014 (UTC)[reply]

Starting paragraph

The paragraph at the beginning says:-

"The ultraviolet catastrophe, also called the Rayleigh–Jeans catastrophe, was a prediction of late 19th century/early 20th century classical physics that an ideal black body at thermal equilibrium will emit radiation with infinite power."

It does not grab me. Try this (though the paragraph following would need to be amended accordingly):-

"The ultraviolet catastrophe, also known as the Rayleigh–Jeans catastrophe, was a prediction (first proposed by Rayleigh and Jeans, made towards the end of the 19th Century and the beginning of the 20th) that an ideal black body at thermal equilibrium will emit radiation at all frequencies. This part of the theory is correct and was uncontroversial; however the theory then went on to suggest that as measured black body radiation frequency increased so the energy associated with that frequency also increased, potentially without limit. The catastrophe arose because (1) the idea of a physical process being without limit is contrary to an idea that in nature there is always a limit (in physical terms : that to produce an infinite amount of energy electrons have to be excited an infinite number of times per second), (2) principally, that observations seriously contradicted this theory and (3) there was no better theory to explain what did happen. Observations revealed that as the measured frequency got higher and higher the energy of the emitted radiation actually decreased with measured frequency and did not increase as the theory attempted to predict. This difference between theory and experiment was called the ultraviolet catastrophe because the departure from the Rayleigh-Jeans theory started to become marked at ultra violet frequencies." — Preceding unsigned comment added by 176.12.107.140 (talk) 06:20, 12 December 2014 (UTC)[reply]

Also, the following sentence is poorly constructed, and its meaning is not clear: "When calculating the total amount of radiated energy, (ie, the sum of emissions in all frequency ranges), shows that it is infinite, contradicting the principles of conservation of energy." Maybe someone with a good understanding of the principle can clean that up a bit...?The tamale (talk) 16:32, 29 June 2016 (UTC){[reply]

Any old source?

Hi, now, 2019, the sources are all in 20th century, has any source near 1900? Mahengrui1 (talk) 21:36, 7 April 2019 (UTC)[reply]

Failures of classical physics

What are the experimental observations made on the Ultraviolet catastrophe ? 102.250.1.44 (talk) 21:02, 7 June 2022 (UTC)[reply]

Is it spelled plank or planck ?

My friend told me its plank not planck just looking to clear this up 2001:569:7263:3900:C577:FB4F:A2CA:51D9 (talk) 01:26, 20 September 2022 (UTC)[reply]

Planck after Max Planck. Headbomb {t · c · p · b} 01:42, 20 September 2022 (UTC)[reply]

Error in equation (or explanation)

In the "Solution" section, \nu is used in the equation for energy but \mu is used in the explanation. These should be the same. I believe that \nu is the traditional symbol, but someone more knowledgeable than myself should decide. Scorwin (talk) 17:38, 9 June 2023 (UTC)[reply]

Thanks for noticing, must have been a typo. Jähmefyysikko (talk) 18:00, 9 June 2023 (UTC)[reply]