We explain what the force of gravity is, how and by whom it was discovered. Also, some examples of this force.
What is the force of gravity?
The force of gravity (or simply "gravity") is one of the fundamental interactions of the nature, which makes bodies endowed with mass they attract each other with greater intensity to the extent that they are more voluminous or are closer to each other. The principle that governs this interaction is known as "gravitation" or "gravitational interaction", and responds in physical as described by theLaw of Universal Gravitation.
It is the same attraction that theEarth on the bodies and objects that are close to it, including us, and that makes things fall. It also determines the movements of the stars space (planets orbiting Sun or moons Y artificial satellites orbiting in turn said planets.
Unlike the other fundamental interactions in the Universe (which are the strong and weak nuclear forces, and the electromagnetism), the force of gravity inexplicably predominates over enormous distances, while the others occur over much shorter distances.
The gravity It is studied in different theoretical frameworks depending on whether it is a mechanical (classical) or relativistic approach.
Usually the units used to work with gravity are units of weight such as kilograms of force, or Newtons (N). This is because the weight of a body is equal to its mass by acceleration of the gravity that the gravitational force of the Earth exerts on him. That is, do not confuse gravity with gravitational force. Gravity is an acceleration and not a force like weight.
The acceleration of gravity on the earth's surface reaches about 9.80665 m / s2.
Who discovered the force of gravity?
The force of gravity was not properly "discovered", since its effects have been known since the beginning of the humanity and the thought. However, theUniversal gravitation law that explains it and allows it to be calculated was proposed by Isaac Newton in 1687, supposedly after receiving the impact of an apple on the head, while resting in the English countryside.
This episode would have revealed to the English scientist that the same force that makes things fall by I usually, keeps the planets in its orbit with respect to the Sun and its satellites regarding them. This was a turning point in the history of modern physics.
Subsequently, the physicist Albert Einstein in the twentieth century, based on Newton and his own findings, postulated hisTheory of General Relativity, in which he reformulated some aspects of Newtonian gravitation.
Thus a new perspective on gravity was inaugurated, called "relativistic." According to her, gravity is not a measure of universal force, but variable, and not only affects the space but also the weather.
Examples of the force of gravity
The force of gravity can be studied in the following examples:
- The free fall of a body in the land surface. The mass of the planet attracts us to it and acts on our mass by printing an acceleration. For this reason, an object that falls for one minute hits harder than one that falls for one second.
- An object thrown into the sky. A cannonball, for example, will fly in a straight line until it undergoes a loss of acceleration, the result of the force of gravity, curving its trajectory. When this exceeds the initial force of the explosion, the object will fall and stop moving.
- Orbiting the Moon around our planet. This movement is due to the fact that the moon is trapped in the gravitational field of the Earth, at such a distance that it cannot move away in a straight line, nor can it collapse towards us and fall.
- Falling meteorites. Attracted by its enormous force of gravity, many meteorites enter the atmosphere of Jupiter, Saturn and other very massive planets, torn from their natural orbit around the Sun.