Annotation: Presented is the theoretical justification of the phenomenon of the inertia initiation under accelerated motion of the body, and gravity origin in the circumterrestrial space. There is no description of the physical nature of the inertia and gravity in the scientific publications. In the phenomenological approach under study, allowing for reflection properties of the space, earlier unknown interdependent information-physical link of the body and its mechanical particles with space under the accelerated motion was determined in the state of rest of the gravitation field as well as in the state of weightlessness. Alongside with the environment, eigenspace, i.e. configuration space of the body and corresponding metric lines of the space are considered. Idea of metric lines agrees with the concept of F. Wilczek, the American physicist, Nobel-Prize laureate, on the existence of the unobservable metric field in the real space. Solution of the problem rests on the example of the cantilever beam and mathematical model of the information reflection process, which for the first time takes into consideration previously unknown property of space reflection. Under the accelerated motion of the body reflection gains the acceleration vector dt d а     . In this case reflection manifests itself in the initiation of the beam of polarization vector under study   ~ in every point of the configuration space and is expressed as     ~ а . Value of the polarization vector equals the value of acceleration vector with negative sign. As a result metric lines of the configuration space under conditions of beam acceleration become polarized lines, generating vector information inertia field. Interaction of mechanical particles with the information inertia field in the configuration space generates physical inertia field of force, providing the real inertia under accelerated motion of the beam. (Relatively slow motion of bodies is studied as compared to the speed of light). According to the set forth unconventional approach the nature of the earth gravity is conditioned by the polarization of the radial metric lines of the circumterrestrial space. And polarization vector is directed to the center of the Earth and equals acceleration vector of the free fall with the same sign. Interaction of the body with specific mass with the vector information field of the Earth generates the physical force field of gravity. Article deals with the fundamental issues of theoretical physics and other fields of natural science. Materials of the conducted research are regarded as a potential scientific discovery.

Annotation: The experimental and theoretical justification is presented for the phenomenon of sudden buckling with dynamic effect at stability loss of a rectilinear rod with real existing imperfections. The interdependent connection is established between the initial imperfections and buckling intensity in the effect of zero rigidity of an utmost compressed rod at stability loss in the large.