How Information Escapes From a Black Hole

Via newscientist.com -

If a black hole eats a book, what happens to the information? The latest work from a team of physicists says that in the distant future, the black hole eventually spits out the book's full contents. Even a black hole can't destroy information.

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Now Ashtekar and colleagues Victor Taveras and Madhavan Vadararajan at Pennsylvania State have put that idea on a firmer footing. They set up quantum equations for the space-time geometry of a black hole, but in a "flatland" universe with just one space and one time dimension. "The equations are similar, and fortunately also much simpler," Ashtekar told New Scientist.

He and his team have traced the quantum state of their simplified black hole as it forms and evolves. In their model, there is no singularity, no edge to space-time, so all the information is preserved.

Eventually the black hole will slowly evaporate in a process called Hawking radiation, and the information will re-emerge. By collecting and analysing that radiation it would be possible in theory to find out what went into the black hole, and even to read any books that fell in.
"If we know the details of quantum gravity, then theoretically we will be able to run the movie backwards and say exactly how the black hole formed," says Ashtekar.

In practice, there would be a few snags. For any reasonable-sized black hole, Hawking radiation is so weak that it will take an immense amount of time to evaporate, vastly longer than the current age of the universe. And although the information would be there in principle, decoding it is liable to be unimaginably complicated.

Journal reference: Physical Review Letters (forthcoming)

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I have been reading a lot about information theory recently and it is truly a amazing idea. Computer science and cryptanalysis were born from information theory.

In the world of information security, we routinely quantify information to assess security risk. However, it isn't easy sometimes....to look around and understand that information is everywhere and contained in everything. It is measurable, just like weight or height.

Every atom, every light ray...every breath is controlled by information...quantum information.

If you are new to information theory, I would highly recommend "Decoding the Universe: How the New Science of Information Is Explaining Everything in the Cosmos, from Our Brains to Black Holes".