How does gravity work?

Gravity is a fundamental force of nature that attracts two masses toward each other. At its core, gravity is what gives weight to physical objects and governs the motion of planets, stars, galaxies, and even light. On Earth, gravity is the reason objects fall when dropped and why we remain anchored to the ground. According to Isaac Newton’s classical theory, gravity is a force that acts at a distance between any two masses. The strength of this force depends on the masses involved and the distance between them: the greater the masses or the closer they are, the stronger the gravitational pull. This idea is captured in Newton’s law of universal gravitation, which mathematically describes how gravity works between any two objects. In the early 20th century, Albert Einstein revolutionized our understanding of gravity with his general theory of relativity. Instead of viewing gravity as a force, Einstein described it as the curvature of spacetime caused by mass and energy. Objects move along the curved paths in this four-dimensional fabric, and this motion is what we perceive as gravitational attraction. This theory explains phenomena that Newtonian gravity cannot, such as the bending of light around massive objects and the precise orbit of Mercury. In summary, gravity is an attractive interaction that arises from mass and energy, either understood as a force between masses or as the effect of curved spacetime. It is essential for the structure and behavior of the universe at all scales.