A concept first proposed by geologist John Michell in 1783 and further developed in 1796 by mathematician Pierre-Simon Laplace of a body so dense that even light would not escape its gravity. The concept was extended to stellar objects by astronomer Karl Schwarzschild in 1916. However, the concept was only theoretical until the recent discovery of Neutron Stars. It is now believed that black holes form when heavy stars collapse at the end of their life cycle into supernovae. Such a Black Hole has so much gravity that attracts other stars, growing ever larger.