A gas consists of atoms of mass m being in thermodynamic
equilibrium at temperature T. Suppose coo is the natural frequency
of light emitted by the atoms.
(a) Demonstrate that the spectral distribution of the emitted
light is defined by the formula
I.= Ioe-a(1--(0100)2,
(I, is the spectral intensity corresponding to the frequency coo,
a = mc2/2kT).
(b) Find the relative width Ow/w0 of a given spectral line, i.e.
the width of the line between the frequencies at which I. = /0/2.