- Study section 6.7 (0 pts).
- Note that radiation in an enclosure can be viewed either as a gas of bosons with zero chemical potential or as a set of an infinite number of harmonic oscillators with frequencies corresponding to the electromagnetic cavity modes. Why does a photon gas have zero chemical potential? (2 pts).
- Problem 6.24 (12 pts; 3 for each part).
- Problem 6.25 (10 pts).
- Show that the mean energy per photon in a blackbody radiation cavity is close to 2.7 \( kT \) (6 pts).
- The sun may be viewed is a black body at 5800 K. Its diameter is \( 1.4 \times 10^9 \) m and the distance from the earth is \( 1.5 \times 10^{11} \) m. Find the equilibrium temperature of a spherical black body orbiting the sun at the same distance as the earth (10 pts).
Total: 40 points.