As one of the fundamental quantities in physics, the gravitational constant was first mentioned in the 18th century. At the same time, the first attempts were made to measure its value, however, due to the imperfection of instruments and insufficient knowledge in this area, it was possible to do this only in the middle of the 19th century. Later, the result obtained was repeatedly corrected (the last time it was done in 2013). However, it should be noted that the fundamental difference between the first (G=6, 67428(67) 10−11 m³ s−2 kg −1 or N m² kg−2) and last (G=6, 67384(80) 10− 11 m³ s−2 kg−1 or N m² kg−2) values do not exist.
Applying this coefficient for practical calculations, it should be understood that the constant is such in global universal concepts (if you do not make reservations for elementary particle physics and other little-studied sciences). This means that the gravitation althe constant of the Earth, Moon or Mars will not differ from each other.
This quantity is a basic constant in classical mechanics. Therefore, the gravitational constant is involved in a variety of calculations. In particular, without information about the more or less exact value of this parameter, scientists would not be able to calculate such an important factor in the space industry as the acceleration of free fall (which will be different for each planet or other cosmic body).
However, Newton, who voiced the law of universal gravitation in general terms, the gravitational constant was known only in theory. That is, he was able to formulate one of the most important physical postulates, without having information about the value on which he, in fact, is based.
Unlike other fundamental constants, what the gravitational constant is equal to, physics can only say with a certain degree of accuracy. Its value is periodically obtained anew, and each time it differs from the previous one. Most scientists believe that this fact is not associated with its changes, but with more banal reasons. Firstly, these are measurement methods (various experiments are carried out to calculate this constant), and secondly, the accuracy of the instruments, which gradually increases, the data is refined, and a new result is obtained.
Taking into account the fact that the gravitational constant is a value measured by 10 to -11 power (which is ultra-small for classical mechanicsvalue), there is nothing surprising in the constant refinement of the coefficient. Moreover, the symbol is subject to correction, starting from 14 after the decimal point.
However, there is another theory in modern wave physics, which was put forward by Fred Hoyle and J. Narlikar back in the 70s of the last century. According to their assumptions, the gravitational constant decreases with time, which affects many other indicators that are considered constants. Thus, the American astronomer van Flandern noted the phenomenon of slight acceleration of the Moon and other celestial bodies. Guided by this theory, it should be assumed that there were no global errors in the early calculations, and the difference in the results obtained is explained by changes in the value of the constant itself. The same theory speaks of the inconstancy of some other quantities, such as the speed of light in a vacuum.
