The book said that the mass of a microscopic oscillator (what is that?) is not continuous, but discrete and the difference between states is an energy quanta: ε = h ν = E k − E i And since m = h ν c 2 then the (relativistic) mass of the photon is m = h ν c 2 How did they deduce that?

Question

The book said that the mass of a microscopic oscillator (what is that?) is not continuous, but discrete and the difference between states is an energy quanta:  ε  =  h  ν  =      E    k    −      E    i  And since   m  =            h      ν              c      2       then the (relativistic) mass of the photon is  m  =            h      ν              c      2      How did they deduce that?

Jorge Franklin · Accepted Answer

This is probably related to the derivation of de-Broglie wavelength... Since photon has wave-particle duality,We could equate Planck&#039;s quantum theory (wave nature) which gives the expression for energy of a wave of frequency   ν, (  E  =  h  ν) with Einstein&#039;s mass-energy equivalence (particle nature) which gives relativistic energy for photon (  E  =  m      c    2  )  m      c    2    =  h  νThe resultant mass gives the relativistic mass for a moving photon (since photon has zero rest mass)