  The binary model of physical vacuum is considered. This model reveals unified
cause-and-effect mechanism of electromagnetic and gravitational interactions.
The model of binary vacuum does not identify physical vacuum to a substance as
the model of mechanical ether does, but presents physical vacuum as the unity
of two simultaneously everywhere existed non-structural electrical elementary
media. They are just the same except for their signs. They diffusively and
uniformly penetrate into each other. Each of them is continuousal and possesses
the elastic modulus of dilatation and the elastic mutual-shearing modulus. The
shearing-strain theory of elementary media describes all modern relative
electrodynamics and answers the unknown before questions: how do the electric
charges, electric and magnetic fields arrange in nature; what are the
cause-and-effect relations in Coulomb and Lorentz forces; why are the
electromagnetic waves transversal. The theory of monolithic (combined)
deformations of world elementary media (near neutral bodies) is the theory of
relative gravitation. In particular it determines unknown before
gravitational-energy density, converts the experimental Newton law of
gravitation into a speculative result.
