Online Encyclopedia
Celestial mechanics
Celestial mechanics is a term for the application of physics, historically Newtonian mechanics, to astronomical objects such as stars and planets. After Einstein explained the anomalous precession of Mercury's perihelion, astonomers recognized that Newtonian mechanics did not provide the highest accuracy. Today, we have binary pulsars whose orbits not only require the use of General Relativity for their explanation, but whose evolution proves the existence of gravitational radiation, a discovery that lead to a Nobel prize: http://www.naic.edu/vscience/astro/nobel.htm
Isaac Newton is credited with introducing the idea that the motion of objects in the heavens, such as planets, the Sun, and the Moon, and the motion of objects on the ground, like horses and falling apples, could be described by the same set of physical laws. In this sense he unified 'celestial' and 'terrestrial' dynamics.