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Planck Arriving at a Relation Between Energy and Frequency with h

  1. Oct 10, 2013 #1

    I have recently been reading some texts focusing on modern physics. Both include sections on Planck and how he arrived at the conclusion that energy is not continuous. However I am confused as to what conditions inspired him to make this leap. I am aware of the Ultraviolet Catastrophe, but is that what led Planck to his epiphany or was it some other conflict in his work?

    Last edited: Oct 10, 2013
  2. jcsd
  3. Oct 10, 2013 #2


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  4. Oct 11, 2013 #3

    Jano L.

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    Beware, that is not what Planck thought! True, in his first papers he used integer numbers to calculate energy changes, similarly to some Boltzmann's statistical calculations. But then it was just a mathematical assumption that allowed them to do calculations.

    Planck did not believe that the radiation was really made of such quanta, because that would contradict the EM theory. In his later work on the thermal radiation he was able to decrease the role of the quanta of energy only to the process of emission by the matter, all else remaining continuous as ever.

    See the paper

    Stephen G. Brush, Cautious revolutionaries: Maxwell, Planck, Hubble, Am. J. Phys. 70, 119 (2002)


    From the paper:

    The great place to learn about Planck's actual thinking on this problem is also his book

    M. Planck, The theory of heat radiation, P. Blakiston's Son & Co., 1914

    Only in his later years, it seems he became more favorable of the idea of real existence of quanta of radiation.
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