The idea of a body so massive that even light could not escape was first put forward by John Michell in a letter written to Henry Cavendish in 1783 of the Royal Society : In 1796 , mathematician Pierre-Simon Laplace promoted the same idea in the first and second editions of his book Exposition du système du Monde ( it was removed from later editions ) .
In 1796 , Pierre-Simon Laplace promoted the same idea in the first and second editions of his book Exposition du système du Monde ( it was removed from later editions ) .