## law of gravity

In 1666, Isaac Newton had made a discovery that changed the way people at the time of the attraction of bodies.It is called the law of universal gravitation.It states that all bodies attract each other with a certain force, depending on their characteristics.The great physicist discovered the law, trying to explain one of the statements of Kepler period of the planet.

This law was discovered by accident.Once Newton walking in the apple orchard.He decided to sit under a tree to rest a little and reflect on their scientific work.After a few minutes his head apple fell.Academic visited inspiration, after which he was able to open its fundamental law.

strength of attraction between two bodies is directly proportional to their masses and inversely proportional to the square of the distance between them.This statement
still held in the school physics course.With it you can solve a lot of problems (for example, determination of the mass of the Earth, the sun and other celestial bodies).In the formula of the law of universal gravitation there is one value - the gravitational constant.It is equal to 6.67 * n * 10-11 m2 / kg 2.Its numerical value is determined in 1867 scientists Cavendish.

Gravity - is the force with which the Earth or any other celestial body attracts objects and people.For different planets of the solar system, it takes different values ​​as one of the masses in the formula, and the distance to the core of the planet will be in each case are different.Even on Earth gravity value unequally across the surface.At the equator, the Earth attracts us more strongly than at the poles.

## Gravitational forces

Gravity - encompassing power.Her field penetrates all bodies in the universe.Despite this, the gravitational interaction remains the most unexplored.All the matter in the absence of a unified quantum theory of gravity because of the great difficulties in its drafting.However, the scientists agreed that the gravitational interaction is transmitted by means of a special quasi-particle - the graviton.It has no mass and is characterized by the spin quantum number equal to 2.

known that the gravitational field is a potential that is its strength depends on the distance between the source and the subject field.This force is directed along the line connecting them.Everyone can be a source field, only the attractive force is negligible.