Gravitation

Gravitation is a natural phenomenon by which all objects attract each other. In everyday life, gravitation is most familiar as the agency that endows objects with weight. 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 hot fluids rise); for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena that we observe. Gravitation is also the reason for the very existence of the Earth, the Sun, and most macroscopic objects in the universe; without it, matter would not have coalesced into these large masses, and life, as we know it, would not exist.