Stephen Hawking has numerous scientific contributions to gravitational singularity theorems in general relativity, and made predictions on the emission of radiation by black holes, called Hawkins radiation.
He recently published an article that contradicts his own theory. In the paper, published under the title “Information preservation and weather forecasting for black holes “, Stephen Hawking says that the event horizon (a boundary in spacetime beyond which events can not affect an outside observer, also called the “point of no return”, ie the point beyond which gravitation becomes so great that any escape is impossible) does not exist.
Consequently, says Hawking, black holes do not exist, in that the light can not escape from the area. But he does concede: there is instead “gray holes” with “apparent horizon” borders delineating matters and temporary light. According to the classical theory it is not possible escape from black holes, Hawking says, but in quantum theory energy and information can escape from there.
He is trying this way to solve the paradox of black hole firewall, a hypothetical phenomenon whereby an observer falling into an old black hole encounter high energy quanta at the event horizon.
Stephen Hawking is an honorary member of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and one of the prize winners of the Presidential Medal of Freedom, the highest civilian award in the United States. Hawking was Lucasian Professor of Mathematics at Cambridge University between 1979 and 2009.