Hawking and how black holes preserve information

[tomBitonti]

Just spotted this:

"Stephen Hawking believes he’s solved a huge mystery about black holes"

http://www.washingtonpost.com/news/...ved-a-huge-mystery-about-black-holes/?hpid=z5

On Tuesday, he explained his new theory: "I propose that the information is stored not in the interior of the black hole as one might expect, but in its boundary, the event horizon," Hawking said. The event horizon is the sort of shell around a black hole, past which all matter will be drawn into the dense object's powerful embrace.

Fascinating.

But, I thought this was the basic notion since a few years ago?

I wonder what are the relevant physics at the event horizon. If information is captured, it should interact (through the underlying encoding mechanism), and there should be a meaningful descriptions of that interaction. Or is the capture entropy maximizing, with nothing much of interest happening afterwards. Could there be a new "universe" created at the event horizon? That would make for interesting analogues, e.g., a "big bang" from the initial formation of the black whole; an "expanding universe" because of in-falling matter.

Thx!
TomB

 

[Umbran]

But, I thought this was the basic notion since a few years ago?

The basic notion that black holes must deal with entropy (and thus information) goes back to the 1970s. I think the new bit here may be in some of the description of details, not the overall notion.

If information is captured, it should interact

That does not follow quite so much, in that black holes are not known for interacting much, except to draw you in and swallow you

A bit of the information from the black hole is carried away with every bit of Hawking radiation coming off of it. It is not lost, but comes off in dribs and drabs, bits not associated in any way meaningful to a human. As the article puts it, it is kind of like burning an encyclopedia - if you keep the ash and smoke, you don't actually lose anything, but good luck looking anything up.

Could there be a new "universe" created at the event horizon?

There are maths that, with proper interpretation, say that upon entering a black hole, you can gain access to spaces that sure look like other universes. But that's not "another universe created at the event horizon". If I recall correctly, access to the other spaces is found near the singularity. In most senses, the event horizon isn't all that special a point - physics breaks down at the middle of the thing, not at the edge.

 

[tomBitonti]

What I was thinking was that the information which is captured when a particle crosses the black hole horizon would be encoded in a thin region near the event horizon. Somewhere I read "the dynamic topology of the event horizon", but I couldn't tell you what that means, other than it sounds nice. But, the information should continue to evolve over time, and, the embedding should interact with other embeddings to modify the information over time.

Making a very rough analogy, if a blip of information creates a "bump" of some sort, some physical feature, near the event horizon, that "bump" should interact with other bumps.

The interactions would seem to be confined to a very narrow region close to the event horizon. Then, the physics of "bump interaction" would be confined to that very narrow region. Incoming particles and particles escaping due to Hawking radiation would create interactions, but otherwise, the interactions would be entirely within the very narrow region. That narrow region is what I'm describing as a "new universe". A part of our universe, but interacting with it only indirectly and following very different rules.

Thx!

TomB

 

[Janx]

We all know Stephen Hawking is smart. But how does he really document his ideas and write papers with that sippy straw?

Is he really just outsourcing ideas to grad students? "hey Phil! write a paper about black holes not destroying information and contradicting that paper I had Bob write 10 years ago. Bob's fired!"

Heck, how do we know it's not the AI in his chair writing all these papers, and he's been trapped getting rolled around from conference to conference?

 

[Umbran]

Making a very rough analogy, if a blip of information creates a "bump" of some sort, some physical feature, near the event horizon, that "bump" should interact with other bumps.

Depends what you consider "interaction". Consider that the surface now becomes a library. You may shuffle books around, and stack them up, and such, but having two books next to each there does not create instead a third book. The surface is an information storage medium, but not a processor - when something falls in, you write to the surface. When something leaves (though Hawking radiation) you delete from the surface. But the surface is not itself a living, self-modifying program. The surface does not evolve, except through adds and deletes.

 

[Umbran]

We all know Stephen Hawking is smart. But how does he really document his ideas and write papers with that sippy straw?

My understanding (which may be faulty, as I've never met the man) is that he has an interface similar to the one he uses for speech, but specialized for his math. And that he can do *way* more in his head that most people can - so much of it may be taking an initial state, thinking about it, and then writing down the final state, and have someone recreate the intermediate steps for publication more quickly than he'd enter them himself.

 

[Morrus]

We all know Stephen Hawking is smart. But how does he really document his ideas and write papers with that sippy straw?

Is he really just outsourcing ideas to grad students? "hey Phil! write a paper about black holes not destroying information and contradicting that paper I had Bob write 10 years ago. Bob's fired!"

Heck, how do we know it's not the AI in his chair writing all these papers, and he's been trapped getting rolled around from conference to conference?

Janx, that's a bit... obnoxious. Why are you accusing the man of fraud?

 

[Janx]

Janx, that's a bit... obnoxious. Why are you accusing the man of fraud?

Sorry, it was meant to be a bit tongue in cheek.

Umbran's answer looks on the mark though:

My understanding (which may be faulty, as I've never met the man) is that he has an interface similar to the one he uses for speech, but specialized for his math. And that he can do *way* more in his head that most people can - so much of it may be taking an initial state, thinking about it, and then writing down the final state, and have someone recreate the intermediate steps for publication more quickly than he'd enter them himself.

Read more: http://www.enworld.org/forum/showth...lack-holes-preserve-information#ixzz3jrovLm2k

It really is impressive how much complex content Hawking generates. As well as how much he likely has to keep in his head in order to work out an idea (math) before he wastes time using the chair to get it serialized.

 

[tomBitonti]

Depends what you consider "interaction". Consider that the surface now becomes a library. You may shuffle books around, and stack them up, and such, but having two books next to each there does not create instead a third book. The surface is an information storage medium, but not a processor - when something falls in, you write to the surface. When something leaves (though Hawking radiation) you delete from the surface. But the surface is not itself a living, self-modifying program. The surface does not evolve, except through adds and deletes.

That's one possibility. But, there would seem to be other possibilities, where there is interaction. One would be like the surface of the ocean, which has interactions, but mostly uninteresting ones. Another could be something more like Conway's game of life, as a simple example having more interesting interactions. What would seem to determine what interactions occur is how the information is embedded physically, and what rules (physics) apply to the embedding. Since the superset of those rules (physics as a whole) allow very complex interactions (weather patterns on Jupiter; life here on Earth), there seems to be a wide range of possible interactions.

Thx!

TomB

 

[freyar]

Well, this could be big news, so I'll try to weigh in on it later once the technical details are out --- all I've seen is a couple of snippets from a conference in the news media, nothing technical. I imagine the paper will be out soon. It will be interesting to see how it relates to other ideas in the literature, as sometimes Hawking's ideas get promoted in the media as a bit more revolutionary than they are these days due to his fame.

On how he gets his work done:
I've not talked to Hawking, but I have seen him give talks several times and worked in institutes where he's had extended visits, and I know some of his former grad students and senior collaborators a little bit. One thing that's worth noting is that his output is simply lower than that of other theoretical physicists of his stature for understandable reasons; I find it ridiculously impressive and practically miraculous he can write papers at all. As for "outsourcing" ideas to grad students, that's both how most professors get some fraction of their work done and also educate the students. Basically, by the time a student is ready to come up with their own ideas, it's probably time for them to graduate. But a good student-advisor relationship is a collaboration. I have no reason to think that is any different for Hawking, though he has the advantage of picking from the very best students at Cambridge and also quite excellent senior collaborators. For example, one news article on this latest idea lists his collaborators as two other pretty famous (in physics circles) physicists, one from Cambridge and one from Harvard. So it should be a pretty high-powered paper.