Note that the shift we predict is a purely quantum effect. In accordance
with the concept of the classical limit, we find that as
, 
, and we recover the
classical prediction of no frequency shift in the scattered radiation.
We interpret this either as the statement that there is no
frequency shift as we turn quantum mechanics ``off'' (
), or as recognition of the fact that if we were to
use a macroscopic values for the mass in 
,
we would find an extremely tiny shift that would not be noticeable in
experiments performed on the macroscopic objects of the type which
concern the experiments leading to the classical Maxwell's equations.