Black holes have long been problematic for physicists — the general theory of relativity suggests information never comes out of them, but quantum mechanics wouldn't allow that to happen. There might finally be an explanation that satisfies both camps, however. Researchers speaking to BBC News claim to have resolved the paradox with a theorem that black holes have "quantum hair," or imprints in their gravitational fields left by components of the stars that formed them. This lets the information that went in also come out without violating either relativity or quantum mechanics.
The apparent solution came about after University of Sussex professor Xavier Calmet and others devised new mathematical techniques to approach the dilemma. It's billed as the "yes hair theorem" in contrast to Prof. John Wheeler's "no hair theorem" from the 1960s, which suggested that black holes were 'bald' entities that had no physical features beyond charge, mass and spin.
This new theorem doesn't put a definitive end to debates. However, Calmet believes it might represent a key step in linking relativity to quantum mechanics and ending the conflict between the two theories. If so, it could prove highly valuable to both astrophysicists and the broader scientific community — they might not have to worry as much about theories breaking down in extreme situations.