Gravity does not exert influence over uniform velocities of expansion of galaxies

Visible universe

A visible universe is a sphere in which the galaxy of observer is in its center. If we divide such sphere into two parts, due to uniform density of universe in the macroscale, each one of such parts will have the same mass with the center of mass symmetric in relation to the center of sphere.
Thus, the gravitational influence of one part compensates the other one. In addition, the resultant of all gravitational forces that come from the universe with such spheric symmetry will be zero. Thus, according to the 1 st Newton’s law, if the resultant of forces that act on a body (galaxy) is null, such body (galaxy) is standing still or at a rectilinear uniform motion (RUM). Finally, we conclude that as the universe is expanding, the galaxy cannot be standing still but at a rectilinear uniform motion. Thus, it is confirmed that the gravitational influence over any galaxy is exerted by its visible universe and the resultant of such forces will always be null. It means that all galaxies will always be at uniform velocities acquired by Big Bang.