  Time interval between the incident and scattered photon in Raman effect and
absorption of photon and emission of electron in photoelectric effect has not
been determined till now. This is because there is no such high level
instrument discovered till now to detect time interval to such a small level.
But this can be calculated theoretically by applying a basic principle of
physics like impulse is equal to the change in momentum. Considering the
collision between electron and photon as perfect inelastic collision in
photoelectric effect, elastic and inelastic collision in Raman effect and
elastic collision in plane mirror reflection and the interaction between
electron and photon as strong gravitational interaction we calculate the
required time interval. During these phenomena there is lattice vibration which
can be quantized as phonon particles.
