"Joy and pleasure are as real as pain and sorrow and one must learn what they have to teach. . . ." -- Sean Russell, from Gatherer of Clouds

"If you're not having fun, you're not doing it right." -- Helyn D. Goldenberg

"I love you and I'm not afraid." -- Evanescence, "My Last Breath"

“If I hear ‘not allowed’ much oftener,” said Sam, “I’m going to get angry.” -- J.R.R. Tolkien, from Lord of the Rings

Wednesday, August 26, 2015

A Little Astrophysics to Wake Up To

Another fascinating insight from Stephen Hawking, on black holes and the information therein -- or not:

A long-standing conundrum related to black holes deals with something known as the “information paradox.” In a nutshell, the laws of quantum mechanics tell us that everything in the universe is encoded with information about its constituent particles’ quantum states. And, this information should never entirely disappear, not even if something gets sucked into a black hole. The fact that this information seems to get irretrievably lost when a black hole inevitably evaporates has frustrated physicists for nearly four decades.

During a lecture at the KTH Royal Institute of Technology in Stockholm on Tuesday, famed British physicist and cosmologist Stephen Hawking presented an idea about how this paradox can be solved. According to him, the quantum-mechanical information about particles falling into black holes doesn’t actually enter the black hole.

“The information is not stored in the interior of the black hole as one might expect, but in its boundary -- the event horizon,” Hawking said, adding that the information is encoded in two-dimensional holograms known as “super translations.”

The problem is that the information is not organized, so that, in practical terms, it is lost, even though it's not. (Don'cha love modern physics?)

I vaguely remember a science-fiction story from years ago in which someone was trapped in orbit around a black hole -- at the event horizon, more or less -- and someone else was trying to rescue them, but it's been a long time and I don't remember the details. The point of that little anecdote is that it may help visualize what Hawking is describing.

One thing that interested me is that I never knew that black holes evaporate, or that it's inevitable.

And Hawking notes that there are other ways out of a black hole short of dissolution. But you'll need to read the article.

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