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There's one thing that has always puzzled me about the derivation of the old classical Rayleigh-Jean Law of blackbody radiation. I understand how they calculate the density of modes in the cavity however I don't see why they assign an "equipartition" energy of kT per mode instead of 1/2 kT as is used for example in the kinetic theory of gases to find the heat capacity of gases.
I'm pretty sure the correct "equipartiion" is 1/2 kT per mode and my hunch is that in the blackbody radiation derivation they use kT to allow for independent vertical/horizontal polarizations, though I've never seen this explicitly stated. Or is it 1/2 kT for the E field and another 1/2 kT for the B field, can someone please enlighten me as to the precise reason.
Thanks. :)
I'm pretty sure the correct "equipartiion" is 1/2 kT per mode and my hunch is that in the blackbody radiation derivation they use kT to allow for independent vertical/horizontal polarizations, though I've never seen this explicitly stated. Or is it 1/2 kT for the E field and another 1/2 kT for the B field, can someone please enlighten me as to the precise reason.
Thanks. :)