Gravity and hologram There are four fundamental forces in the physical world: electromagnetism, strong force, weak force, and gravity. Gravity is the only force still unexplainable at the quantum ...
For Newton it was not precisely the center of the Sun or any other body that could be considered at rest, but "the common centre of gravity of the Earth, the Sun and all the Planets is to be esteem'd the Centre of the World", and this center of gravity "either is at rest or moves uniformly forward in a right line".