  As has been shown before (a brief comment will be given in the text),
relativistic mass and relativistic time dilation of moving bodies are
equivalent as well as time and mass in the rest frame. This implies that the
time dilation due to the gravitational field is combined with inertial and
gravitational mass as well and permits the computation of the gravitational
action of the vacuum constituting the gravitational field in any distance from
the source of the field. Theoretical predictions are compared with experimental
results and it is shown that many known astrophysical and gravitational
phenomena, especially the so-called dark or missing matter, owe their existence
to the gravitational effects of the mass of the field-vacuum.
