Gravity

Gravity is the natural force of attraction that exists between all objects with mass. Although it is the weakest of the four fundamental forces of nature, it becomes the dominant force on large scales because planets, stars and galaxies contain enormous amounts of matter. On Earth, gravity pulls objects toward the planet's center, giving them weight and causing unsupported objects to fall.

The strength of gravity depends on both the mass of the objects involved and the distance between them. Near Earth's surface, the acceleration due to gravity is about 9.8 metres per second squared. Isaac Newton described gravity as a universal force acting between masses, while Albert Einstein later explained it as the effect of massive objects bending the fabric of space-time, providing a more complete description of how gravity behaves under extreme conditions.

Gravity shapes the Universe in countless ways. It keeps the Moon in orbit around Earth and the planets in orbit around the Sun, while also governing the motion of stars within galaxies. Tides are mainly caused by the gravitational pull of the Moon, with a smaller contribution from the Sun. Gravity allows gas and dust to gather and form stars and planets, and it determines the life cycles of celestial bodies.

Everyday activities such as walking, jumping, pouring water or throwing a ball all depend on gravity. Scientists continue to study this fundamental interaction through satellites, telescopes and space missions, improving our understanding of the Universe and helping develop technologies such as accurate satellite navigation and space exploration.