  We find that a competition between dispersion forces among molecules in
solids and their phonon mediated coupling leads to a natural length scale based
on molecular parameters and relevant to decipher glass anomalies. For amorphous
systems, the length scale is of the medium range topological orders and its
ratio with the distance of closest approach between molecules turns out to be a
constant. This in turn leads to a material independent, constant value of the
ratio ${\gamma_l \over \gamma_t}$, with $\gamma_l$ and $\gamma_t$ as the
coupling-strength for two amorphous molecules mediated by longitudinal and
transverse phonons (also referred as Meissner-Berret ratio) and thereby
provides a theoretical explanation of their experimentally obserevd
quantitative universality in \cite{mb}. The above length scales are also
related to Ioffe-Regel frequency and boson peak frequency of the vibrational
spectrum and indicate that the former is of the same order as the latter for
transverse phonon-dynamics.
