Black holes

Schwarzschild calculated that sufficiently massive and dense stars have a point beyond which not even light can escape, known as the Schwarzschild radius. This concept eventually led to the term 'black hole'.
 Karl Schwarzschild Germany 1916 Black holes

Schwarzschild calculated that sufficiently massive and dense stars have a point beyond which not even light can escape, known as the Schwarzschild radius. This concept eventually led to the term 'black hole'.