Physicists at Penn State say they have provided a mechanism by which information can be recovered from black holes; objects from which, according to Einstein's theory of general relativity, not even light can escape. The team's findings pave the way toward ending a decades-long debate sparked by renowned physicist Steven Hawking.
In the 1970s, Hawking stated that black holes evaporate by quantum processes; however, he asserted that information, such as the identity of matter that is gobbled up by black holes, is permanently lost. At the time, Hawking's assertion threatened to turn quantum mechanics--the most successful physical theory posited by humankind--on its head, since a fundamental tenet of the theory is that information cannot be lost.
Hawking's idea was generally accepted by physicists until the late 1990s, when many began to doubt the assertion. Even Hawking himself renounced the idea in 2004. Yet no one, until now, has been able to provide a plausible mechanism for how information might escape from a black hole. A team of physicists led by Abhay Ashtekar, Holder of the Eberly Family Chair in Physics and director of the Penn State Institute for Gravitation and the Cosmos, say they have discovered such a mechanism. Broadly, their findings expand space-time beyond its assumed size, thus providing room for information to reappear.