gravitacionin

Gravitacionin, commonly called gravitation, is the natural phenomenon by which all masses attract one another. It is a pervasive force shaping the structure and motion of objects from everyday things to planets, stars, and galaxies. In classical physics, gravity is described by Newton's universal law of gravitation, which states that every pair of masses m1 and m2 attracts with a force F = G m1 m2 / r^2, where r is the separation and G is the gravitational constant. This law explains planetary orbits, the tides, and the weight felt at Earth's surface as the gravitational pull of the planet's mass on objects.

In the early 20th century, Einstein's general relativity offered a different view: gravity emerges from the curvature of spacetime caused by mass-energy. This framework accounts for phenomena that Newtonian gravity cannot fully explain, such as the bending of light near massive bodies, time dilation in stronger gravitational fields, and gravitational waves—ripples in spacetime detected directly in 2015 and thereafter.

Gravitational strength varies with mass and distance; it is the weakest of the four fundamental forces at the particle level but dominates on astronomical scales. Gravitational acceleration near Earth is about 9.81 m/s^2, and G is measured to high precision in laboratory experiments. Gravitational theory continues to be tested through observations in astronomy, cosmology, and gravitational-wave astronomy.