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Re: Cosmology



on 20/6/04 3:10 PM, Hugh Logan at HloganPHY@CFL.RR.COM wrote in a
contribution to this thread:


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.

SNIP

The article that Hugh refers to was written by James McCaughan, a colleague
of mine, then and now.

James has given me the full reference to this paper and an earlier one of
his:
J.B.T. McCaughan 'Jeans¹ Role in the Law of Black-Body Radiation' Physics
Educ. 15 pp 255-260 (1980)
J.B.T. McCaughan 'Black Body Radiation' Physics Educ. 14 pp 332-333 (1979)

James reminds me: " The main thrust of the Jeans paper was to point out that
Jeans himself was responsible for the wrong history."

Brian McInnes
Honorary appointment
School of Physics
University of Sydney



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