Answer:
Explanation:
In 1784, John Michell proposed that in the vicinity of compact massive objects, gravity can be strong enough that even light cannot escape. At that time, the Newtonian theory of gravitation and the so-called corpuscular theory of light were dominant. In these theories, if the escape velocity of an object exceeds the speed of light, then light originating inside or from it can escape temporarily but will return. In 1958, David Finkelstein used General Relativity to introduce a stricter definition of a local black hole event horizon as a boundary beyond which events of any kind cannot affect an outside observer. This led to information and firewall paradoxes, which encouraged the re-examination of the concept of local event horizons and the notion of black holes. Several theories were subsequently developed, some with, and some without, event horizons.
