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Re: Cosmology

Jack Uretsky wrote:

On Sat, 19 Jun 2004, Brian Whatcott wrote:


The date of the arbitrary fudge factor
identified by Planck which reconciles the Rayleigh-Jeans law
to the experimental black-body curve was 1900.
It's now initialized with a letter that looks much like an 'h'.
Hope this straightens out the dateline.

Planck's remained a lonely voice until a patent clerk illuminated
a clean copper sheet with light of various intensities and
frequencies and used the same fudge factor to fit the
response curve. This did snag a Nobel. What year was that?
Can't recall.

Not exactly (see Richtmeyer & Kinnard,Ch. III). Herts reported
the effect in 1887. The patent clerk explained it in, of course, 1905.

Before Einstein's explanation of the photoelectric effect in 1905, there
were experimental clues beyond those of Hertz and Hallwachs. Philipp
Lenard built the first vacuum photoelectric tube and demonstrated that
energy of photoelectrons depended on the frequency of the incident
radiation and that the number of electrons emitted depended on the
energy of the incident radiation
<http://www.nobel.se/physics/laureates/1905/lenard-bio.html>. However,
he did not provide the explanation that had to wait for Einstein. Lenard
was awarded the 1905 Nobel Prize for his work on cathode rays in
general. Millikan later did very exacting experiments to validate
Einstein's explanation. Einstein did not receive his Nobel Prize for his
work on the photoelectric effect until 1921. Lenard was out of the
mainstream of physics later in life because of his extreme political
views and support of National Socialism, allowing such views to
influence his physics. He wrote an infamous text, _German Physics_.

Hugh Logan

The explanation was not generally accepted; I've seen a paper written in
(as I remember) 1912 that claimed that the electron energy was
proportional to the intensity of the radiation - meaning that the Einstein
relation was awful hard to measure.