Gravitation and Earth's gravity.

Gravitation is a natural phenomenon by which objects with mass attract one another. In everyday life, gravitation is most commonly thought of as the agency which lends weight to objects with mass. Gravitation compels dispersed matter to coalesce, thus it accounts for the very existence of the Earth, the Sun, and most of the macroscopic objects in the universe.

Gravitation is responsible for:

• keeping the Earth and the other planets in their orbits around the Sun;
• for keeping the Moon in its orbit around the Earth, for the formation of tides;
• for convection (by which fluid flow occurs under the influence of a temperature gradient and gravity);
• for heating the interiors of forming stars and planets to very high temperatures; and
• for various other phenomena that we observe.

Modern physics describes gravitation using the general theory of relativity, in which gravitation is a consequence of the curvature of spacetime which governs the motion of inertial objects. The simpler Newton's law of universal gravitation provides an excellent approximation for most calculations.

The terms gravitation and gravity are mostly interchangeable in everyday use, but a distinction may be made in scientific usage.

"Gravitation" is a general term describing the phenomenon by which bodies with mass are attracted to one another, while "gravity" refers specifically to the net force exerted by the Earth on objects in its vicinity as well as by other factors, such as the Earth's rotation. ^[1]