General Relativity reinterprets the force of gravity not as a traditional force but as a manifestation of the curvature of spacetime. Its formulation rests on a rigorous mathematical framework built ...

All bodies in a given gravitational field are thought to fall with the same acceleration. This idea, known as the equivalence principle, is central to our understanding of gravitational physics. It ...

After Albert Einstein published his special theory of relativity in 1905, he spent the next decade trying to come up with a theory of gravity. But for years, he kept running up against a problem. He ...