Talk:Ultraviolet catastrophe

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[edit] 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.

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)

[edit] 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)