Sir Isaac Newton, declared in the year 1687 The Law of Gravity or Universal Law of Gravitation, which explains how everything present in this world, everything that has mass and this compound of particles has a property that he called Gravity.. Gravity is an attractive force, mathematically speaking "Directly proportional to the product of their masses and inversely proportional to the square of the distance that separates them." The Law of Gravity assumes that the larger a body, the force of attraction it will have on a smaller object will be greater. That is why human beings are in a certain way "glued" to the earth, given its great size and composition with respect to us, we are attached to it by a force of gravityrepresented by the following value: 6,670. 10-11 Nm² / kg².
The Law of Gravity was crucial in discoveries of planets, in the deduction of the shape of the solar system and also helped to determine that the sun served as an axis for the whole system and that the planets revolved around it, it was so much importance the enunciation of the law of gravity, that great scientists were involved in its deduction as well as trying to determine if it was wrong.
One of the most important applications of the law of gravity has been the determination of the exact mass of the earth. Galileo Galilei participated in this study and determined that the acceleration of all objects near the surface of the earth, as g = 9.8 m / s2. Consequently, by setting this equation equal to Newton's Law of Universal Gravitation already described, Cavendish determined the mass of the earth with great accuracy.
Henry Cavendish, British Physicist and Chemist, corroborated the Law of Gravity and argued that the law of gravity could have been calculated in need of constants, however, he was considered the creator of some. While Newton's Law of Universal Gravity is still useful today, Albert Einstein proved in 1915 that the law was only approximately correct, and that it did not work when gravity became too strong.
