Modern Physics for Engineers Lecture slides 20b – The Bose-Einstein and Planck distributions

This lecture part states the Bose-Einstein distribution, which gives the number of bosons that should be expected on average in any given state at a given temperature, and derives the simpler version that is the Planck distribution, which applies to photons in particular, telling us the number of photons expected in a photon mode in thermal equilibrium. (slides)