What is called gravitation?

Gravitation is the universal natural phenomenon by which every object in the universe attracts every other object with a force. This force is directed along the line joining the centers of the two objects. Gravitation is one of the four fundamental forces of nature (the others being electromagnetic force, strong nuclear force, and weak nuclear force). Unlike the other forces, gravitation is always attractive in nature; it never repels.

Historically, gravitation was explained by Sir Isaac Newton in 1687 in his Principia Mathematica. Newton described gravitation as the force that causes an apple to fall from a tree and the same force that keeps the Moon in its orbit around the Earth. Later, Albert Einstein provided a deeper explanation through his General Theory of Relativity, in which gravitation was explained as the curvature of spacetime around massive objects.

From a Class 9 perspective, gravitation can be understood as the force of attraction between two masses. For example, the Earth attracts objects towards its center, which is why we experience weight and why objects fall down when dropped. The intensity of this force depends on two main factors:

1. The masses of the objects involved.
2. The distance between them.

The importance of gravitation in daily life cannot be overstated. It is responsible for the existence of the solar system, the movement of planets, the tides in oceans caused by the Moon’s gravity, and the ability of humans to stay grounded on Earth. Without gravitation, life as we know it would not be possible—there would be no atmosphere surrounding Earth, no stable planetary orbits, and no concept of weight.

In physics, gravitation is distinct from gravitational force, which refers to the specific measurable force between two objects. Gravitation is the general property of matter that gives rise to this force. For example, gravitation explains why all planets orbit the Sun, while gravitational force is the specific force acting between the Sun and a planet.

Thus, gravitation can be defined as the universal tendency of all masses to attract each other. Its study provides the foundation for understanding physics, astronomy, and cosmology