General relativity General relativity Mathematical Physics index History Topics Index General relativity is a theory of gravitation and to understand the background to the theory we have to look at how theories of gravitation developed. Aristotle 's notion of the motion of bodies impeded understanding of gravitation for a long time. He believed that force could only be applied by contact, force at a distance being impossible, and a constant force was required to maintain a body in uniform motion. Copernicus 's view of the solar system was important as it allowed sensible consideration of gravitation. Kepler 's laws of planetary motion and Galileo 's understanding of the motion and falling bodies set the scene for Newton 's theory of gravity which was presented in the Principia in 1687.
G is the universal gravitational constant.
After receiving their definitive analytic form from Euler , Newton 's axioms of motion were reworked by Lagrange , Hamilton , and Jacobi into very powerful and general methods, which employed new analytic quantities, such as potential, related to force but remote from everyday experience. Newton 's universal gravitation was considered proved correct, thanks to the work of Clairaut and Laplace . The study of the gravitational potential allowed variations in gravitation caused by irregularities in the shape of the earth to be studied both practically and theoretically. Poisson used the gravitational potential approach to give an equation which, unlike Newton 's, could be solved under rather general conditions. Newton 's theory of gravitation was highly successful.