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Is Plancks function a distribution one?

  1. Mar 16, 2010 #1
    In many textbooks Plancks law or function is also refered to as Plancks distribution.
    But is it a true distribution function?

    I was reading a textbook where it was describing Maxwell-Boltzmann distribution
    (which is a true distribution function since its integral across the range equals 1 )
    and a few pages later it was comparing it with Plancks distribution pointing out how similar they look.

    But is Plancks law a true distribution function?
  2. jcsd
  3. Mar 16, 2010 #2


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    Usually Planck's law is defined so that it is normalized to total power per unit area, rather than 1, which would have made it a probability distribution. But if you ignore the probability definition, it is a distribution.
  4. Mar 16, 2010 #3
    But the form of the Plancks function that gives radiance (Energy/time/area/steradian/wavelength or frequency) is not a probability density function,right?
  5. Mar 17, 2010 #4
    Ok,I got what you said.It is a distribution and should be treated as one.The reason its integral is not 1 is because it is multiplied by a factor to give irradiance, radiance etc.

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