The time dependent solutions of general relativity enable us to talk about the history of the universe and have provided the modern framework for cosmology, thus leading to the discovery of the Big Bang and Cosmic Microwave Background radiation. So far all tests of general relativity have been shown to be in agreement with the theory.
THE COSMIC VIEW OF ALBERT EINSTEIN FREE
These predictions concern the passage of time, the geometry of space, the motion of bodies in free fall, and the propagation of light, and include gravitational time dilation, gravitational lensing, the gravitational redshift of light, the Shapiro time delay and singularities/ black holes. Some predictions of general relativity, however, are beyond Newton's law of universal gravitation in classical physics. Newton's law of universal gravitation, which describes classical gravity, can be seen as a prediction of general relativity for the almost flat space-time geometry around stationary mass distributions. The relation is specified by the Einstein field equations, a system of second order partial differential equations. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. The star field behind the black holes is being heavily distorted and appears to rotate and move, due to extreme gravitational lensing, as spacetime itself is distorted and dragged around by the rotating black holes. Slow motion computer simulation of the black hole binary system GW150914 as seen by a nearby observer, during 0.33 s of its final inspiral, merge, and ringdown.