The true meaning of Newton’s gravitational constant G.

Fortunato Marati

Napoli, Italia

e-mail: fmarati@libero.it

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abstract:

This work analyses the real meaning of Newton’s gravitational constant G.
This constant is necessary to quantify the gravitational force between two bodies but, presumably, it must ride on the global Universe’s mass allocated in the full Universe’s volume at a definite time.
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1. Introduction

The universal gravitational constant G at present is regarded as a numerical factor that must be taken into account in the calculation of the gravitational force between two bodies. This paper suggests that this numerical factor is not a constant but varies over time in the same way of Hubble’s constant Ho ( the ratio of velocity to distance in the expansion of the Universe at the time of observation). It changes with time but it is the same everywhere in the Universe at a given time.
Moreover, investigating its dimensions we notice:
[G] = [m3 / (sec2 * Kg )] .
That is, it depends on a volume, a time squared and a mass. (It is directly proportional to a volume and inversely proportional to the square of a time and a mass).
Now, if G is a universal constant, it seems logical to refer these dependencies to the macroscopic quantities of the Universe. That is the Universe’s volume, the global Universe’s mass and the present time elapsed from Big Bang.
To test this idea now let’s try, for example, to calculate the value of the universe’s density by using the value of G and let’s see if we get a result that is congruent with the value estimated by astronomers.

2. Calculation of the universe’s density by means of Newton’s gravitational constant G and Universe age

The gravitational constant is a physical constant that is difficult to measure with high accuracy. [1]
The 2014 CODATA-recommended value of the gravitational constant is [2]: