Hawking Gracefully, Formally Loses Black Hole Bet 485
Liora writes "Today at the 17th International Conference on General Relativity and Gravitation in Dublin, Cambridge University professor Stephen Hawking said in his talk titled The Information Paradox for Black Holes that he was wrong about the formation of an event horizon in a black hole, and that matter is not destroyed in a way defying subatomic theory, as he had previously believed. According to the talk's short, "the way the information gets out seems to be that a true event horizon never forms, just an apparent horizon." A New York Times story and a Wired story are available, both apparently based on Reuters information." (This is the formal announcement promised last week.)
obNoRegLink (Score:5, Informative)
Anyway, here's the obligatory reg-free link:
Are you looking at ME? [nytimes.com]
(Courtesy of these fine folks [blogspace.com])
Re:obNoRegLink (Score:2, Informative)
we have to show web sites that forcing registration for marketing / tracking purposes leads to a reg database full of crap.
Re:Yikes (Score:4, Informative)
Re:More info.. (Score:2, Informative)
You can read more here: National Academies Press [nap.edu]
"Entering the Sunday Times best-seller list within two weeks of publication, it rapidly reached number one, where it remained unchallenged throughout the summer. The book had already broken many records and indeed went on to break them all stay- ing on the list in Britain for a staggering 234 weeks, and notching up British sales in excess of 600,000 in hardback before Hawking's publisher Bantam decided to paperback the book in 1995."
^-- and that's in Britain only. Who knows how many more in the US.
Re:Good for Hawking (Score:2, Informative)
Some more info here [slashdot.org], but you can probably google for some *real* information ;)
Re:obNoRegLink (Score:2, Informative)
Sure, there is less information from using bugmenot logins, but that isn't what NYT wants. If NYT didn't want a database full over people who visit the site every 6-12 months, they wouldn't require registration at all.
NYT wants a database full of individual readers, so they can track their reading habits, see what people click on, what people are interested in.
Parallel universes (Score:5, Informative)
Summary: Parallel universes aren't ruled out (at least by this article) so keep dreaming big! We'll need those other universes when entropy runs out in this one. Even better, ask someone who knows string theory whether the idea of multiple universes would be ruled out IF Hawking is right. Remember, he just lost a bet. He may be sure this time, but who's to say some bright kid 200 years from now won't have a different perspective... blah blah hypothetical
Yeah, sorta (Score:2, Informative)
Re:Am I missing something? (Score:5, Informative)
All that was needed to predict something odd would happen at this mass was the concept of escape velocity and that light had a velocity, both of which have been known for quite some time.
More info can be gotten at:
http://en.wikipedia.org/wiki/Black_hole
Re:Am I missing something? (Score:5, Informative)
The notion of a body whose gravitational force is so strong that not even light can escape was put forward in the late 1700s, first by a British geologist and later by Pierre Laplace. The solution of General Relativity that would come to be recognized as a Black Hole was put forward by Karl Schwarzschild in 1915, only a short time after Einstein had presented his theory of General Relativity. Schwarzschild developed his solution while serving with the German army, on the Russian front. Chandrasekhar's work was initiated in the 1920s. The idea of "Frozen Stars" remained known to physicists, but wasn't the focus of as much attention as it is nowadays. It wasn't until the late 60s and early 70s that they began to attract more attention, and around that time the phrase "Black Hole" appeared.
A great deal of Hawking's work has been devoted to Black Holes, and he is responsible for a number of significant developments in our understanding of them. In fact, "significant development" doesn't quite do it credit, as some of his ideas were so counter-intuitive (the notion of Black Holes radiating, for one!) as to be totally unexpected. But he definitely did not invent the concept of a Black Hole!
m5brane
Re:Am I missing something? (Score:1, Informative)
Re:Am I missing something? (Score:4, Informative)
Once it was clear that light moves at a finite speed, an English geologist, John Michell [wikipedia.org] realized that one could imagine an object with a gravitational escape velocity greater than c. Such an object would appear black. Of course, the term "black hole" didn't appear until much later.
Re:Am I missing something? (Score:3, Informative)
This has to be.. (Score:1, Informative)
For the many lexically challenged compatriots among us:
"Hawking"
noun: selling goods for a living.
verb: to peddle goods aggressively, especially by calling out.
Re:BBC Article (Score:3, Informative)
In Universe in the Nutshell, Hawking puts the odds at macroscopic time travel being possible at less than 10^(10^60) to one against.
And no, time travel is not crackpot stuff. Time travel is fun stuff!
Synopsis explained (Score:5, Informative)
The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.
The Euclidean path integral is the latest trick in quantum gravity.
The original problem with quantum gravity was that as you "quantitized" space into discrete units, explaining gravity in terms of particles like 'gravitons' and trying to do the math was possible for simplistic interactions like tree diagrams where time generally flowed one way - but extremely hairy and full of infinities if you started looking at loop diagrams where time can flow both ways.
So people like Roger Penrose came at it from a different direction, starting off with definining space-time in a quantitized manner (spin networks, quantum foam, whatever you want to call it) which had the side effect that complex examples of spin networks acted a lot like 3-dimensional Euclidean space.
Once people started talking about space-time like this, math started showing up that helped describe events and the progression of events in this space-time, including the Euclidean path integral which attempts to measure the end result of an interaction of particles in this type of space-time.
(Good link talking about path integrals and how they were a problem with quantum definition of gravity: http://www.damtp.cam.ac.uk/user/gr/public/qg_qc.h
Anyways, it sounds like he's saying: All this new math is great and if the world were a simple place, yeah, black holes would probably have an event horizon and the math to prove it is simple.
But the world is more complex than you think and doing the math for "the real world" shows that the closer you get to the end result, the less and less predictable the end result will be, even though overall it looks like it has a defined end result (i.e. it looks like it _should_ have an event horizon). In reality it's constantly shifting around - and likely this amount of shifting around is representative of the original information/particle system that went into its formation but you won't be able to trace it backwards and extract what the original information was.
This will probably tie into time dialation which will make it be: We never get to the end result event horizon that 'should' be there and in the process of never getting there, the black hole will have a nice jiggly event horizon as a result of all that information - but so jiggly we can't tell what went in to it, all we can do is measure the jiggliness.
What he hasn't explained is how he knows this and the math behind it.
Crap I'm bored.
JOHN TITOR was Right on this one! (Score:1, Informative)
Darby (of anomalies.net) won't be happy, I'm sure.
John Titor claimed to be a time-traveller from the future.
From the johntitor.com website's news page:
JOHN TITOR SAID STEVEN HAWKING WAS WRONG ABOUT BLACK HOLES - NOW HAWKING AGREES!!!
When John Titor visited our worldline in 2000 - 2001, he gave certain physical details about the physics and engineering behind his time machine. He stated the machine operated through the use of two mini black holes that produced a gravity field that allowed passage from one worldline to another. In march of 2001, John got into a discussion about his machine with his arch nemesis, Darby. For those unfamiliar with Darby, he is currently the moderator at the Time Travel forum at http://www.anomalies.net.
For the last four years, Darby has been hell-bent on driving people away from the idea of time travel and John Titor specifically. In their last few conversations before John left, Darby and John went back and forth on many subjects where Darby took great pride in trying to out-maneuver John over his physics statements. As time went on, John has proven to be correct on many of the bizarre statements he had made. It appears he was right about another.
Darby attacked John on a routine basis (and still does) based on Steven Hawking's theories on black holes. When John was here, Steven Hawking believed that mini-black holes were impossible to contain because they would evaporate and disappear in something called "Hawking Radiation." Here is a short question and answer between Darby and John:
"MARCH 14, 2001
DARBY: It's Hawking Radiation you can't overcome.
JOHN: Yes, that is true. If you firmly believe that Hawking radiation cannot be controlled or goes on even without the presence of virtual particles forever until the singularity explodes than you are correct. "
As it turns out, Hawking has now re-thought his views on this subject and he now agrees with John.