# What is gravity? Concept, Measurement, Units and Examples

## What is gravity?

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

The Law of Universal Gravitation was formulated by Isaac Newton in 1687.

Gravity or force of gravity is a phenomenon of nature by which bodies possessing mass attract each other reciprocally, with greater intensity the more voluminous those bodies are.

This is one of the four fundamental interactions of matter, and is also known as “gravitation” or “gravitational interaction”.

This attraction is what the planet Earth exerts on all the objects on it, and 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 plan and end up disintegrating in the atmosphere.

The general law of physics governing 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 gravity that makes things fall to the ground is what keeps the planets in their orbit with respect to the Sun.

Very later, in the twentieth century, the 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: the relativist, according to which gravity would not only affect space, but also time.

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

### How do you measure gravity?

The force of gravity is measured in relation to the acceleration it imprints on the objects on which it acts, as long as no other forces to be considered intervene. This acceleration has been estimated at about 9.80665 m/s2 on the Earth’s surface.

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, as other forces, in kilograms of force, that is, in Newtons (N).

### Gravity measurement units

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

### Examples of gravity

An example of the force of gravity can be the planets that revolve around the sun.

Some examples that show the action of gravity are the following:

• The acceleration presented by an object in free fall, as we said before: when the gravitational force acts on it together with its own mass, the speed at which it moves increases progressively in time.
• The opposite case: an object thrown with all our forces in a straight line, will suffer a deceleration in its movement as the out of gravity overcomes the initial force that we print on it, and ends up forcing it to fall freely.
• The orbiting of planets around larger stars, such as the planets around the Sun, or the moons and natural satellites around the planets. So it is with our very 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 rips them from their orbit around the Sun and imposes a course of collision with their respective surfaces.

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