The Big Bang

In the Back ground of ultraviolet catastrophe, Planck put forward his daring hypothesis of discontinuous process of energy-exchange and assumed that the basic quantum of energy  is proportional to the frequency.

                  E = hv
where, h = Planck’s Const.
              v = Frequency .

And the energy of an oscillator can only be an integral Multiple of E , i.e. , nE (=nhv), where n = 1,2,….,n is called the Quantum Number . 

So, the Mean Energy of an oscillator E is then given by ,

And not KT , as given by the classical law of equipartition of energy invalidates the equipartition law.

• The Success of Planck’s quantum hypothesis raises the question : What actually is the nature of radiation? For , Planck’s hypothesis doubts the wave nature of it. In the mean time, the pioneering work of Einstein on photo electricity in 1905 put the Planck’s hypothesis on a still firmer footing.