5.3 Gravity of a common cosmic object
5.3.1 Gravity at zero speed above the surface of a common cosmic object
In the chapter 4.9
we found quantity of a mass to be proportional to a spaceflow quantity.
Therefore the equation (101) may be modified:

(162) 

where
 K
 is constant, and,
 m
 stays for mass of the gravitational object
Applying equation (138b) at r_{lmx}=r_{lm},
we can derive:

(163) 

It will be shown later, that, except of the case when v_{m/x} approaches very closely the speed
of light (in the orbital frame of the space density = 1), the equation (163)may be used in form:

(163a) 

This is why (see also equations (138a) and
(146b) ) we may write:

(164) 

Applying equations (162) and (164) we can derive:

(165) 

Since K is constant, the ratio r_{x}/v_{m/x} must be constant as well.
Applying equations (142) and (144),
we receive:

(166) 


(167) 

where T_{g}
 stands for the time constant of a gravitational field. This constant must be considered as
an universal constant not dependent neither on a mass, nor on a spacetime density of a
spacetime structure surrounding mass. Physically may be interpreted as a time interval,
the any orbit of the spacetime structure would take to meet singularity point, provided
that the respective orbital spacetime density remained the same on its way to a singularity.
Applying equations (165) and (166) the equation (162) may be rewriten to an universal form:

(168) 

Solving the equations (166) and (168), we obtain:

(169) 


(170) 

Remark:
Generalizing the equation (162), we may write:
Applying equations (165), (166) and (167) we can calculate the proportionality factor between
mass and the flow of the space falling into it:
The validity of equations (169) and (170) is usually restricted on a relatively small region
around a cosmic object. This is because the spacetime density in a system to which a cosmic
object belongs is determined by a dominant cosmic object of the system, as it is Sun in the
solar system.
The equations defining the spaceflow speed and its acceleration above the surface of a common gravitational object,
can be derived by substitution of the basic gravitational parameters:
r_{x} from equation (169), and
v_{m/x} from equation (170),
to equations (114), (108)
(131), (132),
(137), (138a), and
(138b) .