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Need help with understanding an idea

  1. May 20, 2010 #1
    Hello !

    I'm just a passionate reader of popular physics books.
    Often i'm in trouble understanding concepts and ideas.
    hopefully this time someone here will help me...

    I'm reading atm "From certainty to uncertainty", the book of David Peat.

    He mentions in the first chapter about 2 clouds that darken the sky of classical physics at the end of the 19th century:
    the luminiferous ether problem (I'm familiar with it)
    "the problem of distributing energy equally among vibrating molecules"
    (later on , "the way in which the energy is shared by vibrating molecules").

    Since it has something to do with black body radiation, as the author mentions, i chose to ask the question in this category.

    So, can anyone shed some light here? What problem David Peat is talking about ?

    If someone could explain it in layman's terms, I'd be grateful...
    Last edited: May 20, 2010
  2. jcsd
  3. May 20, 2010 #2
  4. May 25, 2010 #3
    tks for your answer...I think you are right ...the author is probably refering to the ultraviolet catastrophe.

    could you pls enlighten me a bit more about this so called "catastrophe"? I have an idea about the phenomenon, but I can't say it's all clear...

    He (David Peat) writes later in the chapter about:

    Waves can be of any length, with an infinite range of gradations.
    By analogy with sound and water waves, the waves of light radiated
    from a hot body were assumed to have every possible length and
    every possible frequency; in other words, light had an infinite number
    of gradations from one wavelength to the next

    I don't understand what this infinite number of gradations is about...
    Last edited: May 25, 2010
  5. May 25, 2010 #4
    I would take it to mean the the allowed wavelengths are not discrete, in other words if I have a range of frequencies F1 to F2, then every frequency in the range F1 to F2 is allowed. That means that, in evaluating the contribution of a range of frequencies, we have to use integration rather than summation.
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