  Gravity is related to gravitational mass of the bodies. According to the weak
form of Einstein's General Relativity equivalence principle, the gravitational
and inertial masses are equivalent. However recent calculations (gr-qc/9910036)
have revealed that they are correlated by an adimensional factor, which depends
on the incident radiation upon the particle. It was shown that there is a
direct correlation between the radiation absorbed by the particle and its
gravitational mass, independently of the inertial mass. This finding has
fundamental consequences to Unified Field Theory and Quantum Cosmology. It was
also shown that only in the absence of electromagnetic radiation this factor
becomes equal to one and that, in specific electromagnetic conditions, it can
be reduced, nullified or made negative. This means that there is the
possibility of control of the gravitational mass by means of the incident
radiation. This unexpected theoretical result was recently confirmed by an
experiment (gr-qc/0005107). Consequently there is a strong evidence that the
gravitational forces can be reduced, nullified and inverted by means of
electromagnetic radiation. This means that, in practice we can produce
gravitational binaries, and in this way to extract energy from a gravitational
field. Here we describe a process by which energy can be extracted directly
from any site of a gravitational field.
