... Schwarzschild solution stress energy tensor black hole event horizon trapped region big bang cosmological constant diffeomorphisms pull back push forward Lie derivative 3 1 decomposition lapse shift vector triads spin connection density Leibniz rule space-time curvature covariant derivative...

... by the space-time curvature. The geometrical structure explains why objects fall on massive objects like earth. Space-time curvature is explained using embedding diagrams. Tests of the general theory of relativity like the bending of light around the sun, the precession of the perihelion of Mercury...