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# What is gravity?

We explain what gravity is and how this phenomenon of nature can be measured. In addition, its units of measure and some examples.

1. ### What is gravity?

Gravity or force of gravitye is a phenomenon of nature by which bodies that have mass attract each other in a reciprocal manner , with greater intensity as more bulky are said bodies. It is one of the four fundamental interactions of matter , and it is also known as “gravitation” or “gravitational interaction”.

This attraction is the one that the planet Earth exerts on all the objects on it, and it makes things fall. But it can also be observed among space stars, such as the planets that orbit the Sun (attracted by its gravity) or the meteorites that are attracted by the mass of our plans and end up disintegrating in the atmosphere .

The general law of physics that governs gravitational action is (in classical mechanics) the  Law of Universal Gravitation , formulated by Isaac Newton in 1687. In it the English scientist explains that the same gravitye that makes things fall to the ground is the that keeps the planets in their orbit with respect to the sun .

Very later, in the twentieth century, physicist Albert Einstein postulated his Theory of General Relativity, in which he reformulated certain aspects of gravitation and inaugurated a new perspective on the phenomenon: relativistic, according to which gravity would not only affect the space , but even time .

Unlike the other fundamental interactions in the Universe , gravitye seems to be the predominant force over great distances (the other three occur in much more immediate distances), responsible for the movement of the celestial stars and many interactions of the stellar matter.

1. ### How is gravity measured?

The force of gravitye is measured in relation to the acceleration it prints on the objects on which it acts, provided that no other forces to consider are involved. This acceleration has been calculated, on the earth’s surface, at about 9.80665 m / s2.

On the other hand, gravitational force can be measured through different formulas , depending on the specific physical approach (classical or relativistic mechanics), and is usually represented, like other forces, in kilograms of force, that is, in Newtons (N).

1. ### Gravity measurement units

As we said recently, gravitye can be measured in Newtons (N) when its magnitude is represented, and in m / s2 when measuring the acceleration it exerts on bodies attracted by another of greater mass, such as an object in free fall from Any building.

1. ### Examples of severity An example of the force of gravity can be the planets that revolve around the sun.

Some examples that confirm the action of the force of gravity are the following:

• The acceleration presented by an object in free fall, as we said before: by acting on it the gravitational force along with its own mass, the speed at which it moves progressively increases over time.
• The opposite case: an object thrown with all our forces in a straight line, will suffer a slowdown in its movement as the out of gravity overcomes the initial force we print on it, and ends up forcing it to fall freely.
• The orbitation of the planets around larger stars, such as the planets around the Sun, or the moons and natural satellites around the planets. This is the case with our same planet and our moon, for example.
• Meteorites that enter the Earth or other major planets, for example, do so attracted by the gravity of the planet, which plucks them from their orbit around the Sun and imposes a crash course on them with their respective surfaces.