Rule, the attraction between masses of Newton
Astronomers and scientists observed that in ancient times the Moon orbiting the Earth, the Earth and the various planetary section completes its circuit Sunday by the orbit of the Moon or the planets look like an ellipse or circle even though the cache rule is found paloe (Kepler), the orbit of a planet around the Sun, but still nobody can explain why in Earth orbit, this behavior until Newton's observations have led astronomers to conclude that a planet because the Sun completes its circuit load between the Sun and the planets.
He believed that this force is the attraction between masses of the Sun to the mass of the planet, and yet believe that gravity is the force between the mass and gravity are between all kinds of objects with mass in the universe, Newton proposed a rule which has entice force between masses, that.
"When all objects in the universe, will exert a mutually attracted by the size of the attraction between objects allow a variable matches the product between the two objects, and the mass is the inverse to the squared distance between two objects.