Calculation of Mass Energy Density for a Collapsing Dust Sphere

In this paper, we have considered an internal state of a collapsing body including in the course of the process its compression below the Schwarzschild (Schwarzschild, 1916) sphere, which requires the solution of the Einstein equations for the gravitational field in the material medium. In the centrally symmetric i.e. the velocity at each point must be directed along the radius, it represents the field outside a spherically symmetric mass in otherwise, empty space, later was also recognized as the solution representing both the outside and the inside of a non-rotating black hole.