Show us the math. That would be one way to sum up the physics community's response to Stephen W. Hawking's headline-making announcement this July that he had solved the black hole information paradox, a profound puzzle of quantum physics and gravity that he himself uncovered 30 years ago. For although he presented an outline of his new theory at the General Relativity 17 meeting in Dublin, he has not yet released a research paper detailing all the mathematical steps that lie behind the general reasoning. "We are waiting for the preprint," says physicist Joe Polchinski of the University of California at Santa Barbara.
The information paradox arises out of two contradictory properties of black holes. Analyzed classically, that is, without taking account of quantum mechanics, anything that falls within the hole's event horizon is lost from the universe forever. Nothing--neither light nor information--is fleet enough to emerge from the hole's intense gravitational clutches. Hawking discovered a quantum chink in this armor in 1974, when he deduced that black holes should in fact emit a random trickle of particles and radiation (now called Hawking radiation).
This article was originally published with the title Hawking a Theory.