Schwarzschild radius

American  

[shvahrts-shilt, shwawrts-chahyld, -shild] / ˈʃvɑrtsˌʃɪlt, ˈʃwɔrtsˌtʃaɪld, -ʃɪld /

noun

Astronomy.

1. the radius at which a gravitationally collapsing celestial body becomes a black hole.

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Schwarzschild radius British  

/ ˈʃvartsʃɪlt, ˈʃwɔːtsˌʃɪld /

noun

1. astronomy the radius of a sphere ( Schwarzschild sphere ) surrounding a non-rotating uncharged black hole, from within which no information can escape because of gravitational forces

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Schwarzschild radius Scientific  

/ shwôrts′chīld′,shvärts′shĭld /

1. A radius defined for a body of a given mass and proportional to that mass, such that if the body is smaller than that radius, the force of gravity is strong enough to prevent matter and energy to escape from within that radius. The Earth is much larger than its Schwarzschild radius, which is approximately 7 mm (0.28 inches). Black holes are examples of objects smaller than their Schwarzschild radius, which defines the radius of their event horizon. The Schwarzschild radius is a consequence of Einstein's General Relativity theory. It is named after the German astronomer Karl Schwarzschild (1873–1916).

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Etymology

Origin of Schwarzschild radius

1955–60; named after Karl Schwarzchild (1873–1916), German astronomer

Example Sentences

The sun, for example, has a real radius of nearly 700,000 kilometers, but its Schwarzschild radius is only three kilometers.

From Scientific American

So what happens when the object’s radius is equal to its Schwarzschild radius?

From Scientific American

His work predicted a “Schwarzschild radius”—a radius that denotes how compact an object would need to be to prevent light from escaping its gravitational pull.

From Scientific American

Spacetime curves by an amount relative to an object’s Schwarzschild radius divided by its actual radius.

From Scientific American

To deal with the complexities of general relativity where spacetime curved in the extreme, as with objects the same size as their Schwarzschild radius, Penrose came up with a set of mathematical tools.

From Scientific American