When physics lessons in primary school teacher mentions pre-existing idea of the planet Earth as the plane resting on whales, elephants and tortoises, then appear on the faces of the students in the class and a smile even heard laughter.It is now many are already in kindergarten knows that the earth - is a ball and the force of gravity acts on all material objects.But let us at least for a moment that on the gravity we know nothing.How then to explain that people are held on the surface of the oceans and the water is not poured into the void of space, if you do not use the concept of a flat world?If the force of attraction of a mystery to us - then, perhaps, no way.That is why it is so important is understanding the past, because every time - their discoveries.

strength of gravitational attraction was discovered by Newton in 1666.Before him, tried to explain the attraction of such outstanding scientists of his time, like Huygens, known for his works on centrifugal force, Descartes and Kepler, formulated three basic laws governing the movement of celestial objects.However, these were only assumptions, based more on conjecture rather than on fact.None of them did not give a holistic understanding of the world order.Newton also intended to create a complete theory, under which could be explained by the force of attraction and related phenomena with it.And he succeeded.It was formulated not only theoretical background with formulas, and set up a full-fledged model.It was so successful that even now, centuries later, the general theory of relativity, as the development of ideas of Newton, is used in the calculations of celestial mechanics.

Its formulation is very simple and memorable: the force with which attracted objects depends on their masses and distances.This definition is expressed as follows:

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

where M1 and M2 - An array of objects;R - is distance.

usually familiar with the classical theory begins with this formula.For a more accurate representation of the entire right side to be multiplied by the gravitational constant.

conclusion that the more massive the object, the more strongly attracted the impact it has on the environment.It is absolutely not matter whether it is a sphere of 1 kg, or a point with the same weight.At the same time, the calculation of the two bodies, for example, the Sun and the Earth, the latter attracts the same way to the star itself.The force of attraction of the earth, interacting with the field of the sun, forms the common center of gravity around which there is a mutual appeal.It just seems that the sun - the center of our system.The true, although it is in a star with the physical midpoint does not coincide.

attractive force can be determined in the framework of the classical law of universal gravitation under two conditions:

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

- the potential of the gravitational field is relatively small.

Soon after the completion of work on Newton's attraction, it became apparent the need for significant improvement.The fact is that although the body motion of the celestial sphere can be counted using the proposed formula, there are situations when Newton's theory is inapplicable, since it gave a completely unpredictable results.

shortcomings were eliminated by Einstein, who suggested seriously modified model takes into account the speed of light, and very strong gravitational fields.Now, however, even a general theory of relativity has ceased to be a universal answer to all questions: in the microcosm of its postulates are wrong.