Sunday, October 23, 2011

Gravitation

Gravitation is an interaction in the nature which can subordinate to itself all bodies which have weight. Nevertheless gravitation exists only in space, the given name as exists in section of physics which studies the given action.
Gravitational interaction
This one of four most basic interactions which exist in our world. If to consider the classical mechanics it is possible to describe the given action by the law of universal gravitation of Newton which says on that an attraction between bodies the weights divided into distance it and are gravitation.
Possibility to enter potential energy an attraction of pair bodies, says that a weight field potentially, this potentiality specifies to us as in the new law of preservation of the sum of kinetic and potential energy.
The given gravitational interaction, says that the massive body, as though did not move, but nevertheless it depends only on correct position of a body at the moment.
Such space objects as planets, stars and galaxies in itself create gravitational fields which depend on the big weight of the given objects, and it is necessary to notice that in the given period gravitation is very weak interaction.
Gravitation is a unique interaction which has influence not only on a matter, but also on energy, and is as objects in which the gravitational charge is not looked through at all.
Structure of galaxies and as black holes, it is processes, which directly svjazanny with gravitation. This interaction was one of the very first which managed to be described matematicheski. And here Aristotle considered that all objects fall with different speed which depends on their weight, and Galileo Galilej has proved that it at all so. The general theory of a relativity has appeared in 1915, it was described by Albert Einstein, the given theory more all approaches under the gravitation description.

The heavenly mechanics and its some problems
 The section of mechanics studying movement of bodies in empty space only under the influence of gravitation is called as heavenly mechanics.
The most simple problem of heavenly mechanics is gravitational interaction of two bodies in empty space. This problem dares analytically up to the end; result of its decision often formulate in the form of Kepler's three laws.
At increase in quantity of co-operating bodies the problem sharply becomes complicated. So, already well-known problem of three bodies (i.e. movement of three bodies with nonzero weights) cannot be solved analytically in a general view. At the numerical decision, quickly enough there comes instability of decisions concerning entry conditions. In application to Solar system, this instability does not allow to predict movement of planets on the scales, exceeding one hundred millions years.
It is possible to find the approached decision in some special cases. The most important is the case when weight of one body it is essential more weights of other bodies (examples: solar system and dynamics of rings of Saturn). In this case as a first approximation it is possible to consider that easy bodies do not co-operate with each other and dvizhutsja on keplerovym to trajectories round a massive body. Interactions between them can be considered within the limits of the theory of indignations, and to average on time. Thus there can be not trivial phenomena, such as resonances, attraktory, a randomness and etc. the Bright example of such phenomena — not trivial структурa rings of Saturn.
Despite attempts to describe behaviour of system from a great number of drawn bodies approximately identical weight to make it not udyotsja because of the phenomenon of dynamic chaos.

Source: ru.science.wikia.com

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