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Plank's Hypothesis

  1. Aug 11, 2012 #1
    Can you guys please explain to me planks hypothesis? This is what I know. But I need a better understanding:
    Planck’s hypothesis was designed to explain the problem of black-body
    radiation and the observed ‘ultraviolet catastrophe,’ not reconcilable with
    classical physics. Classical physics predicted (via laws of thermodynamics) that
    the radiation emitted by a black body was different to that observed in real life.
    Classical theory predicted as the wavelength of the black body radiation
    decreased, the radiance would increase to an infinite amount (could not be
    reconciled with laws of conservation of energy). Thus an explanation had to be
    Planck proposed a theory of quantum physics, which stated that all energy is
    quantised. As such, all the energy exchanged within the black body exists as

    I need to know the mathematics behind Plank's Hypothesis, how did he come up with his explanation?
    Einstein extended the concept of quantised energy to light waves, reasoning
    that the energy from light waves may be treated as a stream of discontinuous
    quanta, called ‘photons’. This contribution to quantum theory was based upon
    Planck’s hypothesis on the quantisation of energy emitted from a black body.
    A photon is the smallest amount of radiation energy possible at a particular
    frequency. A photon cannot transfer part of its energy: it can only transfer all of
    its energy or none of it. The amount of energy carried by a photon is
    proportional to its frequency. The intensity of light is proportional to the number
    of photons. The energy possessed by a photon is proportional to its frequency
    (the shorter the wavelength - the higher the frequency - the greater the total
    energy). The energy of photons is given by: E=hf.

    So Plank's Hypothesis was limited to energy only, Einstein is the one who extended it to EMR?
  2. jcsd
  3. Aug 11, 2012 #2
    Planck saw the introduction of the constant as nothing more than a mathematical trick that reproduced the experimentally observed spectra; he didn't believe that it represented anything physically. Einstein realised it was more than just a mathematical trick, it represented an actual physical phenomenon, and he used this to explain the photoelectric effect.
  4. Aug 11, 2012 #3
    Wow, thank you, this explains it all.
    So Plank just found a mathematical explanation to the bell curve?
    Are you aware of the equations he used?
  5. Aug 11, 2012 #4
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