What is the force of attraction?

When in physics lessons in primary classes the teacher mentions the existing idea of the planet Earth as a plane resting on whales, elephants or turtles, then the faces of the students appear smiles and in the class even laughs are heard. It is now many already in the kindergarten know that the Earth is a ball, and the force of attraction affects all material objects. However, let us at least for a moment imagine that we know nothing about gravity. How, then, can we explain that people are kept on the surface, and the water of the oceans is not poured into the emptiness of outer space, if not to use the notion of a flat planet? If the power of attraction is a mystery to us - then, perhaps, in any way. That is why it is so important to understand with the past, because each time - their own discoveries.

The force of gravitational attraction was discovered by I. Newton in 1666. Prior to him, such outstanding scientists of his time tried to explain gravitation, like Huygens, known for his works on centrifugal force, Descartes, and also Kepler, who formulated the fundamental three laws to which the movement of celestial objects is subject. However, these were only assumptions based more on guesswork than on facts. None of them gave a holistic understanding of the world order. Newton also intended to create a complete theory, within which the force of attraction and the phenomena associated with it could be explained. And he succeeded. Not only theoretical premises with formulas were formulated, but a full-fledged model was created. It turned out to be so successful that even now, centuries later, the general theory of relativity, being a development of Newton's ideas, is used in calculations of celestial mechanics.

Its formulation is extremely simple and memorable: the force with which objects are attracted depends on their mass and distance. This definition is expressed as follows:

F = (M1 * M2) / (R * R),

Where M1 and M2 are object masses; R is the distance.

Usually acquaintance with the classical theory begins with this formula. For a more accurate representation, the entire right-hand side should be multiplied by the gravitational constant.

The conclusion is the following: the more massive the object, the stronger the attractive impact it has on the environment. In this case, it is completely unimportant, whether it is a sphere with a mass of 1 kg, or a point with the same weight. At the same time, when calculating a system of two bodies, for example, the Sun and the Earth, the latter just as surely attracts the star to itself. The force of gravity of the earth, interacting with the field of the Sun, forms a common center of mass around which mutual circulation occurs. It just seems that the Sun is the center of our system. The true, though it is in the star, does not coincide with the physical midpoint.

The force of attraction can be determined within the framework of the classical law of universal gravitation under two conditions:

- the speed of the objects of the system under consideration is much less than the speed of the light beam;

- the potential of the gravitational field is relatively small.

Shortly after the completion of Newton's work on attraction, it became evident the need for its substantial refinement. The fact is that although the motion of the bodies of the celestial sphere could be calculated with the help of the proposed formulas, sometimes there were situations when Newton's theory proved to be inapplicable, since it produced completely unpredictable results.

The shortcomings were eliminated by Einstein, who proposed a seriously modified model that takes into account both the speed of light and the too strong gravitational fields. However, even now such a general theory of relativity has ceased to be a universal answer to all questions: in the microworld, its postulates turn out to be wrong.