Schwarzschild radius From Wikipedia, the free encyclopedia (Redirected from Schwartzchild radius) The relation between properties of mass and their associated physical constants. Every massive object is believed to exhibit all five properties. However, due to extremely large or extremely small constants, it is generally impossible to verify more than two or three properties for any object. The Schwarzschild radius (rs) represents the ability of mass to cause curvature in space and time. The standard gravitational parameter (μ) represents the ability of a massive body to exert Newtonian gravitational forces on other bodies. Inertial mass (m) represents the Newtonian response of mass to forces. Rest energy (E0) represents the ability of mass to be converted into other forms of energy. The Compton wavelength (λ) represents the quantum response of mass to local geometry. The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the radius of a sphere such that, if all the mass of an object is compressed within that sphere, the escape speed from the surface of the sphere would equal the speed of light. An example of an object smaller than its Schwarzschild radius is a black hole. Once a stellar remnant collapses below this radius, light cannot escape and the object is no longer directly visible.[1] It is a characteristic radius associated with every quantity of mass. The Schwarzschild radius was named after the German astronomer Karl Schwarzschild who calculated this exact solution for the theory of general relativity in 1916. Contents [hide] 1 History 2 Parameters 3 Formula 4 Black hole classification by Schwarzschild radius 4.1 Supermassive black hole 4.2 Stellar black hole 4.3 Primordial black hole 5 Other uses for the Schwarzschild radius 5.1 In gravitational time dilation 5.2 In Newtonian gravitational fields 5.3 In Keplerian orbits 5.4 Relativistic circular orbits and the photon sphere 6 See also 7 References 8 External links History[edit] In 1916, Karl Schwarzschild obtained an exact solution[2][3] to Einstein's field equations for the gravitational field outside a non-rotating, spherically symmetric body (see Schwarzschild metric). Using the definition M=\frac {Gm} {c^2}, the solution contained a term of the form \frac {1} {2M-r}; where the value of r making this term singular has come to be known as the Schwarzschild radius. The physical significance of this singularity, and whether this singularity could ever occur in nature, was debated for many decades; a general acceptance of the possibility of a black hole did not occur until the second half of the 20th century.