When were black holes first theorized?
Using Newton’s Laws in the late 1790s, John Michell of England and Pierre-Simon Laplace of France independently suggested the existence of an “invisible star.” Michell and Laplace calculated the mass and size – which is now called the “event horizon” – that an object needs in order to have an escape velocity greater than the speed of light. In 1915, Einstein’s theory of general relativity predicted the existence of black holes. In 1967 John Wheeler, an American theoretical physicist, applied the term “black hole” to these collapsed objects.