  It was demonstrated (gr-qc/9910036) that the gravitational and inertial
masses are correlated by an adimensional factor, which depends on the incident
(or emitted)radiation upon the particle. There is a direct correlation between
the radiation absorbed(or radiated) by the particle and its gravitational mass,
independently of the inertial mass. Only in the absence of electromagnetic
radiation the mentioned factor becomes equal to one. On the other hand, in
specific electromagnetic conditions, it can be reduced, nullified or made
negative. This means that there is the possibility of the gravitational masses
can be reduced, nullified or made negative by means of electromagnetic
radiation. This unexpected theoretical result was confirmed by an experiment
using Extra-Low Frequency(ELF) radiation on ferromagnetic material
(gr-qc/0005107). Recently another experiment using UV light on phosphorescent
plastic have confirmed the phenomenon. We present a complete explanation for
the alterations of the gravitational field in luminescent materials. This work
indicates that the alterations of the gravitational field can be sufficiently
strong to invert the gravity on luminescent materials.
