Introduction: Phenomenon of Gravitation, Inertia and Weightlessness

Abstract

A brief story and the physical meaning of forces of gravitation , inertia, weightlessness and reference systems are discussed in this chapter . The theories of gravitation put forth by Newton and Einstein are considered in some detail. This is because, in spite of the criticism and enormous number of alternative versions, the above two theories have remained up to now to be the basis for construction of physical and mathematical models in celestial mechanics, astrophysics, geophysics and global dynamics as a whole. We draw attention to the fact that all the theories are based on the hydrostatic equilibrium of motion. In this connection the majority of researchers dealing with dynamics of the Earth and the planets (Munk and MacDonald, Jeffreys and others) come to the unanimous conclusion that the theories based on hydrostatics do not give satisfactory results in comparison with observations. Some of them straightly say that the theories are incorrect. In any case, the fact of j initiated this saying on the question about the nature of gravitation that “I frame no hypotheses”. In our case, on the basis of the results obtained by studying celestial body motion in the framework of Jacobi dynamics, we come to the conclusion that the point of gravitation determines the integral dynamical effect of elementary particles’ interaction energy which is the innate discrete-wave substance. The problem of inertia forces is most difficult in mechanics because there are too many different classifications depending on accepted reference systems and previous solutions. At some unknown time, a fiction force was introduced as a mathematical base for the D’Alambert principle . Polygamy of the forces is a weak place in mechanics and in different gravitation theories. Newton proposed three main forces that are inertial , impressed and centripetal. The centripetal force has three more varieties like absolute, accelerative and motive. Euler and D’Alambert also posited a number of forces. For such a large number of forces, use of the corresponding mathematical apparatus has to be developed. The vector, tensor, spinor and matrix calculus were developed and the work in that field became continuous. Each of them represents a special scientific direction in mathematically complicating solutions of practical physical, astrophysical and geophysical problems. In scientific literature, the physical meaning of the term “weightlessness ” is defined as a complicated state. In relevant encyclopaedias one can find that weightlessness is the state of a material body moving in a gravity field by gravity forces that do not initiate mutual pressure of the body’s particles on each other. The weightlessness effect in cosmic space is compared with man’s feelings in the free fall of an elevator. Unfortunately, such a definition of weightlessness contains neither the nature of the unique phenomenon, nor real physical understanding. It is stated in physics that matter in the world, from the elementary particles to the Universe and their force fields, is continuously moving. Absolute rest is impossible. The philosophers say that the motion is the mode of existence of matter and this law is realized by energy. The forms of motion are different in quantity and in quality, and that difference is a subject of scientific and practical interest for human activity. Explanation of the relationship between different forms of motion appears to be the key for understanding a picture of the world development in the framework of the energy conservation law. Gravitation is the most mysterious natural phenomenon in the face of which even science shirks. Modern astrophysics states that the regularities of elementary particles’ interaction may open a basic way for understanding laws of motion in the nature. Understanding of those laws is the subject of scientific research. In our case, on the basis of the results obtained by studying celestial body motion in the framework of Jacobi dynamics, we come to the conclusion that the point of gravitation determines the integral dynamical effect of elementary particles’ interaction energy which is the innate discrete-wave substance. Let us start our analysis of the existing approaches in studying gravitation with Newtonian gravitation.