It is considered one of the pillars of physics that the incredible gravitational pull created by the collapse of a star will be so strong that nothing can break free...much of this is thanks to Hawking’s own work.
But Hawking smashes this idea by saying that rather than there being an inescapable event horizon, we should think of a far less total “apparent horizon”. And, at a stroke, he has contradicted Albert Einstein.
He sets out his argument in the paper, called Information Preservation and Weather Forecasting For Black Holes, which is likely to send his fellow scientists into a spin.
Hawking writes: “The absence of event horizons means that there are no black holes — in the sense of regimes from which light can't escape to infinity.”
He suggests that light rays attempting to rush away from the black hole’s core will be held as though stuck on a treadmill and that they can slowly shrink by spewing out radiation.
Hawking told leading science magazine Nature: “There is no escape from a black hole in classical theory. [But quantum theory] enables energy and information to escape from a black hole”.
The professor’s grey hole theory would allow matter and energy to be held for a period of time before being released back into space.
The physicist admits that his idea requires a new theory that merges gravity with the other fundamental forces of nature. But he added: “The correct treatment remains a mystery.”
Hawking’s latest work was prompted by a talk he gave via Skype to a meeting at the Kavli Institute for Theoretical Physics in Santa Barbara, California, in August 2013.
He is attempting to solve what is known as the black-hole firewall paradox, which has puzzled scientists for almost two years. It stems from a “thought experiment” where scientists tried to imagine what would happen to an astronaut unlucky enough to fall into a black hole.