1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Planck's law derivation

  1. Jun 15, 2014 #1
    The derivation of Planck's law in my textbook begins with the assumption that the energy of an oscillator with frequency ##\nu## is quantised in units of ##h\nu##. It follows that the average energy of such an oscillator (in equilibrium with a reservoir at temperature ##T##) will be
    [tex]<E>=\frac{h\nu}{e^{h\nu/kT}-1}.[/tex]

    Then, the textbook asserts that the average energy of a mode of electromagnetic radiation with frequency ##\nu## will be the same, and I don't see why this should be true.
     
  2. jcsd
  3. Jun 15, 2014 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    I think they are just saying that electromagnetic radiation in a resonating (black-body) cavity at temperature T behaves in a way that is analogous to the quantum oscillator: ie. the distribution of energies of electromagnetic waves inside the resonating cavity is given by Planck's law.

    AM
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Planck's law derivation
  1. Planck's radiation law (Replies: 3)

Loading...