General Relativity & Curved Spacetime: Physical Mechanisms

The theory relates a spacetime metric, which determines intervals and geodesics, to the stress-energy content of matter and fields. Weak fields reproduce Newtonian gravity closely, while strong fields produce black holes, significant time dilation, and gravitational waves.

Mass-energy changes spacetime geometry; that geometry determines how matter and light move. Because the field equations are nonlinear, gravitational fields themselves contribute to the dynamics, enabling phenomena such as waves and strongly interacting compact binaries.

General relativity correctly predicts Mercury's anomalous perihelion advance, gravitational redshift, light deflection, Shapiro delay, frame dragging, binary-pulsar orbital decay, black-hole dynamics, and directly detected gravitational waves.

Matter-energy changes geometry and geometry guides motion. Because the equations are nonlinear, gravitational fields interact with themselves and can support propagating waves or strongly dynamical merger spacetimes.