Black Holes Don’t Erase Information, scientists say
According to a recent research paper, the "information loss paradox" in black holes—a problem that has overwhelmed physics for almost 40 years—may not exist. Shred a paper, and you can piece it back together. Burn a book, and you could hypothetically do the same thing. But if you send information into a black hole, it's lost forever. That's what many physicists have debated for years: That black holes are the crucial vaults, objects that suck in information and then evaporate without leaving behind any signs as to what they once enclosed. But recent research indicates that this perception may not be true. Dejan Stojkovic, PhD, associate professor of physics at the University at Buffalo, says "According to our work, information isn't lost once it enters a black hole. It doesn't just disappear." Dejan Stojkovic's recent study, "Radiation from a Collapsing Object is Manifestly Unitary," published on March 17 in Physical Review Letters, with his UB PhD student Anshul Saini as co-author.
The paper sketches how interactions among particles released by a black hole can disclose information about what lies inside, such as features of the object that made the black hole to initiate with, and features of the matter and energy drawn inside. This is a significant discovery, Stojkovic says, since physicists who believed information was not vanished in black holes have struggled to demonstrate, mathematically, how this take place. His paper offers clear calculations signifying how information is preserved, he says. The research marks an important phase toward resolving the "information loss paradox," a problem that has overwhelmed physics for nearly 40 years, since Stephen Hawking first suggested that black holes could emit energy and evaporate over time. This posed a massive problem for the field of physics because it intended that information inside a black hole could be eternally lost when the black hole vanished—a violation of quantum mechanics, which says that information must be conserved.
Information hidden in particle interactions
In the 1970s, Hawking suggested that black holes were capable of radiating particles, and that the energy lost through this procedure would cause the black holes to contract and ultimately vanish. Hawking further established that the particles produced by a black hole would offer no signs about what lay inside, meaning that any information present inside a black hole would be totally lost once the object disappeared.
Though Hawking later said he was incorrect and that information might escape from black holes, the topic of whether and how it's conceivable to recover information from a black hole has remained an area of discussion. Stojkovic and Saini's recent paper helps to simplify the story.
Instead of observing only the particles a black hole releases, the study also takes into account the delicate interactions between the particles. By doing so, the study finds that it is possible for an observer outside of a black hole to pull through information about what lies inside the black hole.
Interactions between particles, explained by Stojkovic and Sain, can range from gravitational attraction to the interchange of mediators like photons between particles. Such "correlations" have long been identified to occur, but many researchers discounted them as insignificant in the past.
Stojkovic says "These correlations were often ignored in related calculations since they were thought to be small and not capable of making a significant difference. Our explicit calculations show that though the correlations start off very small, they grow in time and become large enough to change the outcome."
Science journal: http://goo.gl/zIrHSC
Black Holes Don’t Erase Information, scientists say Reviewed by Umer Abrar on 4/06/2015 Rating: