  The generalization of Einstein's special theory of relativity (SRT) is
proposed. In this model the possibility of unification of scalar gravity and
electromagnetism into a single united field is considered. Formally, the
generalization of the SRT is that instead of (1+3)-dimensional Minkowski space
the (1+4)-dimensional extension G is considered. As a fifth additional
coordinate the interval S is used. This value is saved under the usual Lorentz
transformations in Minkowski space M, but it changes when the transformations
in the extended space G are used. We call this model the extended space model
(ESM). From a physical point of view our expansion means that processes in
which the rest mass of the particles changes are acceptable now. If the rest
mass of a particle does not change and the physical quantities do not depend on
an additional variable S, then the electromagnetic and gravitational fields
exist independently of each other. But if the rest mass is variable and there
is a dependence on S, then these two fields are combined into a single united
field. In the extended space model a photon can have a nonzero mass and this
mass can be either positive or negative. The gravitational effects such as the
speed of escape, gravitational red shift and deflection of light can be
analyzed in the frame of the extended space model. In this model all these
gravitational effects can be found algebraically by the rotations in the (1+4)
dimensional space. Now it becomes possible to predict some future results of
visible size of super massive objects in our Universe due to new stage of
experimental astronomy development in the Radio Astron Project and analyze
phenomena of the star V838 Monocerotis explosion as possible Local Big Bang
(LBB).
