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Re: Cosmology

Jack Uretsky wrote:

Hi all-
Brian's a bit behind the times and a bit off on dates.

On Fri, 18 Jun 2004, Brian Whatcott wrote:


I am not the one to poke fun at cosmogonists who seek to compose
the irreconcilable: I simply recall that the squirming point of the
fin du 19ieme century


"ultra-violet catastrophe" usually refers to early calculations in
quantume electrodynamics. Quantum mechanics was invented in the 1920's.
What 19th century paper is referred to here?

I haven't gotten around to following all of this thread, but the
ultraviolet catastrophy that I first heard about was attributed to
Rayleigh and Jeans, who correctly applied incorrect classical physics
to blackbody radiation in an isothermal cavity, leading to the
prediction that the intensity of radiation from the cavity approaches
infinity as the wavelength approaches zero -- in the direction toward
the ultraviolet going from the visible. This was fixed by Max Planck's
assumption that the normal modes of electromagnetic radiation in the
cavity could have energies equal only to an integral multiple of their
frequency times a constant. The constant that made it agree with
experiment was Planck's constant. At least that is the way I remember
it. This may be found in almost any undergraduate book on modern
physics. Actually, the texts rewrite the history of how Planck arrived
at his radiation law, just as they do for Einstein's special theory of
relativity. Around 1969 or 1970, there was an article in the British IOP
counterpart of TPT, "Physics Education," I believe, explaining that the
presentation of Planck's radiation law in texts was different from the
way Planck actually arrived at it. In one of George Gamow's popular
books, there was a picture of a fireplace with an assertion to the
effect that there would be an immense amount of ultraviolet, X-ray, and
gamma ray radiation emitted from it if the Rayleigh-Jeans law with its
"ultraviolet catastrophe" were correct.

Hugh Logan