Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Ultaviolet Catastrophe

  1. May 6, 2004 #1
    Hi, my first post. Forgive my niaivity. And please correct any mistakes I make. I am just an interested novice.

    My question relates to the ultraviolet catastrophe. I believe the Rayliegh-Jeans Eq implied that the energy intensity of black body radiation (at specific temperatures) diverges to infinity as the wavelength shortens. This was shown experimentally to not be the case by Planck et al. However what I would like to be able to understand is how and why that inspired Planck to suggest that energy is emitted in quanta. :confused:

    I hope I asked the question correctly.
  2. jcsd
  3. May 6, 2004 #2
    I am not 100% confident of my answer. If there is any mistake please correct someone.
    I remenber that I read one popular science book which said:
    Planck was investigating his equation which was discovered by optimal fitting to data of the experiment and happened to realize that the equation can be described by an sum of some geometric series. Then he discovered each term of the geometric series can be interpreted as energy is discrete.
    Last edited: May 6, 2004
  4. May 6, 2004 #3


    User Avatar
    Homework Helper

    There was another fit (by Bolzman?) that attempted to eliminate this catastrophe before Planck. It had the hump and everything, but it didn't go back down to zero, which was also unacceptable.

    It isn't even reasonable.
  5. May 10, 2004 #4
    thanks shchr. although not answered as i'd hoped, you have at least pointed me in the right direction. combined with some investigation myself I may then find out why. was hoping to avoid the mathematics but it seems thats unavoidable. thankfully mechanical engineering maths is fairly comprehensive, trouble is I havent used most of them since I was taught them some years ago. geometric series' especially. that was 1st year stuff. i'll post the results of my investigation for other baffled novices like myself.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook