Unlike an ideal gas, a photon gas does not conserve this quantity; instead, this quantity scales with volume and temperature cubed. For 10 points each:
[10m] Name this quantity that is conserved in the microcanonical and canonical ensembles, but fluctuates in the grand canonical ensemble.
ANSWER: particle number [or N; or number of particles]
[10h] The product of the Riemann zeta function and this function appears in the expression for the particle number of a photon gas. The constant prefactor of the N-dimensional Maxwell–Boltzmann energy distribution can be written as “one over this function of N over two.”
ANSWER: gamma function [reject “gamma distribution”] (The Maxwell–Boltzmann distribution can be written as the gamma distribution.)
[10e] The product of the number density and energy density of a phonon gas reproduces the Stefan–Boltzmann law of these objects. These idealized objects absorb all light.
ANSWER: blackbodies [or blackbody]
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