domingo, outubro 02, 2016

Soft Hair on Black Holes – Supertranslations: “Black Holes – The Reith Lectures” by Stephen Hawking



Published May 2016.




“The Einstein Equations don’t work at a singularity”


In “Black Holes – The Reith Lectures” by Stephen Hawking



“In space, no one can you scream; an in a black hole, no one can see you disappear.”

In “Black Holes – The Reith Lectures” by Stephen Hawking



If you’re in the mood for physics, Hawking's paper, published 2016, states at the very end:

“We have reconsidered the black hole information paradox in light of recent insights into the infrared structure of quantum gravity.  An explicit description has been given of a few of the pixels in the holographic plate at the future boundary of the horizon.  Some information is accessibly stored on these pixels in the form of soft photons and gravitons.  A complete description of the holographic plate and resolution of the information paradox remains an open challenge, which we have presented new and concrete tools to address.”

Combining the book with the above-mentioned paper, what did I get? More questions than answers, that's what. I'm not an expert on holes, black or otherwise, but after having studied shit like this when the dinosaurs were still roaming Earth, some random fragments still resurface. First of all, can’t the area of black hole event horizon be not big enough to carry all the information that fell into the black hole?

I though I'd get some insight by reading both works in tandem. No such luck. While reading both (the book comprises two lectures given at BBC Radio: “Do Black Holes Have No Air?”, and “Black Holes Ain’t as Black as They Are Painted” in 2016), some questions popped into my tiny little brain: How do supertranslations save the information? What happens to the event horizon using Hawking’s approach? As far as I can understand the paper and the book, I don’t get how the mechanism is able to "save the information". Is Hawking and his acolytes proposing that in going states have double size from what’s commonly perceived? On top of that, how can the supertranslation storing avoid the transition into mixed states from pure states and vice-versa? Again, as far as my aged brain can perceive this stuff, Hawking, Perry and Strominger (the authors of the above-mentioned paper) believe they have invalidated the no-hair hypothesis in general relativity, and that if you drop something into a Schwarzschild radius, you get not a larger exact Schwarzschild metric, but something with permanent supertranslation distortion applied to it. Can someone in the audience confirm my take on this, please…?

Incidentally, even “Interstellar” makes an appearance in the book. I think “Interstellar” was one of crappiest SF ever made. How did the astronaut not die whilst he was being pulled into the black hole? The gravitational forces were so great (as they would be) to break up his ship and yet he was able to survive in his space suit alone? And more than that interact with a construct in the Black Hole that could never have been made in the first place. That construct was the key to the movie and it made no sense at all. At that time, I screamed bloody murder! Up until that point I though the movie was just getting along nicely, although it was rather slow in pace, as well as being full of potholes, but then it went in a completely ridiculous direction, turning it into shitty SF. It feels like Nolan really wanted to make a hard SF along the lines of 2001, but he thought that would alienate most viewers, so he threw in a ton of sentimentality and family drama. To me these two wildly different aspects didn't mesh together well, and that's where many of my problems with the film lie. I think it would have been an infinitely better film if he was just brave enough to keep it as hard SF. As it is it's just a J. J. Abrams look-alike movie-wise... I love to suspend disbelief when I go to the movies. I frequently overlook plot-holes and other things that don't make much sense. But this movie pushed that envelope way too far.

I have to do some more reading about this supertranslation stuff; so far I am perplexed about what it is and how it works…

Hawking’s book/paper is far too short for stuff like this.




SF = Speculative Fiction.

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