Newtonian gravity accurately describes gravitational forces and motions far from black holes and is used to infer black hole masses from orbital dynamics, but it fails in strong-field regions where relativistic effects dominate.
Escape velocity is the minimum speed an object must have to move away from a massive body and never fall back under its gravity, assuming no additional forces such as atmospheric drag or propulsion. Escape velocity is the minimum speed needed to overcome gravitational attraction, determined by how massive and compact an object is.
Where: \(G\) is the gravitational constant, \(M\) is the mass of the body, and \(R\) is the distance from its center.
The Schwarzschild radius is the characteristic radius associated with a mass at which relativistic gravitational effects become extreme. For a non-rotating, uncharged object, it defines the location of the event horizon of a Schwarzschild black hole.
Where: \(G\) is the gravitational constant, \(M\) is the mass of the object, and \(c\) is the speed of light.
Gravitational time dilation is the phenomenon predicted by General Relativity in which time passes at different rates depending on the strength of the gravitational field. Clocks located deeper in a gravitational well run more slowly than clocks far away from massive objects.
In General Relativity, gravity is not a force acting in time; it is a manifestation of curved spacetime. Because spacetime itself is distorted by mass and energy, the passage of time is affected. The stronger the gravitational field, the greater the curvature, and the slower time flows relative to a distant observer.
Where: