Last August, theoretical physicist Stephen Hawking revealed that he and two colleagues were working on a paper that could finally resolve the black hole information paradox, a controversial phenomenon which essentially states that physical information is destroyed by black holes.
The paradox exists because information about physical matter should not permanently disappear—not even in these dense, gravitationally-strong regions of space time—based on fundamental rules of science that state that the data should, in principle, be fundamentally conserved.
Now, Hawking and co-authors Malcolm Perry from the Centre for Mathematical Sciences at the University of Cambridge and Andrew Strominger from the Center for the Fundamental Laws of Nature at Harvard University, have at long last published their highly anticipated paper online at the arXiv prepublication server and provided details about their new hypothesis.
The paper is extremely technical in nature, but as ScienceAlert and ScienceNews explained, the possible solution to the information paradox lies in so-called “hairs” believed to form on a black hole’s event horizon. These “hairs” could form a kind of two-dimensional hologram that would essentially preserve an object’s blueprint—even if its physical parts are destroyed.
How Hawking radiation can transmit an object’s information blueprint
More than four decades ago, Hawking first proposed that the universe was filled with so-called “virtual particles” that, based on scientists’ knowledge of quantum mechanics, come in and out of existence and annihilate each other on contact—unless they appear on either side of an event horizon, that is. In this case, one is consumed and the other radiates into space.
As that radiation escapes, it takes some of the energy of the black hole with it, causing the black hole to slowly lose mass and eventually vanish altogether. Based on Hawking’s original proposal, the information swallowed up by a black hole should be lost forever, which should be impossible according to the theories of quantum mechanics. Thus, the information paradox was born.
In 1973, theoretical physicist John Wheeler first made reference to a black hole’s “hair” when he said that they had none, by which he meant that they were featureless. This launched a debate: if black holes had no hair, it mean that there was no discernible difference between any of them, no matter how much information they had consumed, ScienceAlert explained. But if they have hair, as Hawking argues, there should be slight deformities that make each one distinct.
These deformities could then potentially be used to determine what information a black hole had consumed during its lifetime, and in their new paper, Hawking and his colleagues assert that they have made progress towards proving that these hairs do actually exist. As Strominger noted in an interview with Scientific American, they demonstrate that when a charged particle enters, it adds a soft photon, a “hair”, to the black hole, allowing it to act like “a recording device”.
Then, as the black hole ejects photons (a phenomenon called Hawking radiation), light particles could collect the information blueprint from the black hole’s event horizon and transport it back into the universe, resolving the paradox. Now that the paper has been published online, it will be able to undergo a peer review, and if Hawking is correct in saying that the existence of the hairs can be proven, his would could ultimately earn him a Nobel Prize.
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Feature Image: Wikimedia Commons
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