  The joint realm of quantum mechanics and the general-relativistic description
of gravitation is becoming increasingly accessible to terrestrial experiments
and observations. In this essay we study the emerging indications of the
violation of equivalence principle (VEP). While the solar neutrino anomaly may
find its natural explanation in a VEP, the statistically significant
discrepancy observed in the gravitationally induced phases of neutron
interferometry seems to be the first indication of a VEP. However, such a view
would seem immediately challenged by the atomic interferometry results. The
latter experiments see no indications of VEP, in apparent contradiction to the
neutron interferometry results. Here we present arguments that support the view
that these, and related torsion pendulum experiments, probe different aspects
of gravity; and that current experimental techniques, when coupled to the
solar-neutrino data, may be able to explore quantum mechanically induced
violations of the equivalence principle. We predict quantum violation of the
equivalence principle (qVEP) for next generation of atomic interferometry
experiments. The prediction entails comparing free fall of two different linear
superpositions of Cesium atomic states.
