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History 181B: Modern Physics
Class 15 (2/24/03)
The quantum: Planck on radiation
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| Navigation |
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| Outline |
Questions about light
Theoretical interest, practical interest
Some basic vocabulary
Spectra: Continuous and discrete
Studying the continuous spectrum
Relating emission and absorption: universality
What is a black body, and where can we find one?
Thermodynamic successes
Planck takes up the question
Thermo, EM, and the nature of the second law
Planck's oscillator model
The snag: Experimental deviations
What Planck cared about: More than just curve-fitting |
| Names
and terms |
| Primary |
Secondary |
Max Planck (1858-1947), NP 1918
wavelength (lambda), frequency (f or nu)
nu = c / lambda (c is the speed of light)
spectrum (emission and absorption)
cavity radiation
Imperial Institute of Physics and Technology (PTR)
Wien distribution law
Wilhelm Wien (1864-1928), NP 1911
infrared |
Stefan-Boltzmann law: energy ~ T4
simple harmonic oscillator |
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| Assignment |
Cathryn Carson, "The Origins of the Quantum
Theory," Beam Line (Stanford Linear Accelerator Center) 30:2 (2000):
6-19, also on the web
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First assignment: Read through p. 13.
How did Planck come to be interested in blackbody
radiation?
What did Planck originally think was the significance
of the constant h?
What did Einstein suggest about radiation that went
beyond Planck? |
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Copyright © Cathryn Carson 2003 |