general relativity

A geometrical theory of gravity developed by Albert Einstein in which gravity's effects are a consequence of the curvature of four-dimensional space-time. According to this theory, the energy and momentum of all matter and radiation cause curvature in space-time, in a way similar to the creation of electric and magnetic fields by electric charges and currents. This curvature also opens the possibility that the universe is closed, having finite volume but without any boundary. Among the many experimentally confirmed consequences of General Relativity are the perihelion precession of the planet Mercury, the bending of light in a gravitational field, and the slowing of time in a gravitational field.

See also closed universe