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Famous Hawking Black Hole Bet Resolved?
Mick Ohrberg writes "In 1997 the three cosmologists Stephen Hawking, Kip Thorne and John Preskill made a famous bet as to whether information that enters a black hole ceases to exist -- that is, whether the interior of a black hole is changed at all by the characteristics of particles that enter it. It now looks like Stephen Hawking and Kip Thorne may owe John Preskill a set of encyclopedias of his choice, since physicists at Ohio State University 'have derived an extensive set of equations that strongly suggest that the information continues to exist -- bound up in a giant tangle of strings that fills a black hole from its core to its surface.'"
Steven had posited in the 70's that the black holes leak (Hawking radiation), but the paradox is that they radiate a 'black-body' spectrum (entirely thermal radiation) in inverse proportion to their mass (so as they get smaller, the radiation increases). The problem here is that all the information went in, but it's very difficult to infer information from a black-body radiated spectrum (!). Steven therefore thinks that information is lost forever.
:-). I don't think the fact that the string-theory radius matches the black-hole radius is sufficient to prove the case, though it's an interesting pointer, a curious coincidence if indeed it is such ...
:-)
The article though is a bit hand-wavy over why the information is preserved in this new theory... (I guess Nth dimensional maths doesn't appeal to the reporter
Effectively this is a conjecture - if the strings continue to exist, then they'd have the same size as the black hole appears to have. The throwaway statement " That means a black hole can be traced back to its original conditions, and information survives." seems a bit of a stretch though
Simon
Physicists get Hadrons!
string theory does not predict anything that could be tested, so there is nno evidence for/against it.
this is also why quite a few people feel its more philosphy than science
Bzzzt. Wrong.
To make laws that man cannot, and will not obey, serves to bring all law into contempt.
--E.C. Stanton
Why not consult Official String Theory Web site :)
"It is not how things are in the world that is mystical, but that it exists." -Ludwig Wittgenstein
when Professor Hawking is released from hospital following a recent health scare...and also when the police have finished their investigation into who has been abusing and torturing him for months now.
Paul
My web domain.
Here is an actual reproduction of the bet document you are thinking of:
Hawking/Thorne bet
Ain' the web grand?
Yeah, Stephen lost that one. Word has it that Kip's wife was a bit miffed about the payoff.
KFG
Look here for a series of clips discussing the string theory, the 'M' theory, and a lot of stuff that led up to it.
In 1975, he bet Kip Thorne a subscription to Penthouse (the loser would get it mailed to his home) that a celestial mystery named Cygnus X-1 would turn out to be a black hole.
I think the point is that while you may be able to understand physics, at an abstract level, can you understand it at a concrete level? Our real world experience is mainly a matter of the concrete. Things we can see, and touch, and hear. I drop something, it falls down. I push something, it moves, etc. Physics, however, is completely abstract. You can't see an atom --- you can't even visualize what it would look like if you could see it. The only way to truely understand it is to understand the mathematical model of it. But even when you have that understanding, you don't have something equivilent to your real world experiences. You still can't see it.
A deep unwavering belief is a sure sign you're missing something...
Responding as I am taking a string theory course from Prof. Zwiebach here at MIT ...
... just not right now. For instance, compactified extra dimensions (as SR includes) introduce additional energy terms to simple quantum problems (i.e. "particle in a box" problems, and SHOs). The problem is that these effects are very large; ergo, the energies necessitated to test these theories are somewhat higher than we can accomplish.
... well, quite a few people aren't physicists. *shrugs*
String theory certainly does predict a number of things that are easily testable
Yes, it's a theory, yes it's kinda off-the-wall and feels a bit contrived, but, studying it, I gotta say that it's pretty if nothing else. It's elegant enough and compelling enough - in terms of what it promises to explain - that it's worth following until it's found to actually be wrong.
A quantum theory of gravity might not be so motivating to you, but if you're a physicist, it's worth trying something wonky to get to it. (Speaking of which, Quantum Loop Gravity - also very wonky - is awesome).
And, as for "quite a few people" finding it too philosophical
I actually recently responded to a similar accusation against physicsists, and you can read my reply here . That response has more examples listed of 'kludges' in physics, but I'll talk about a few in more depth in this post.
What you've just described is known as phenomenology. In other words, trying to come up with some sort of basic theory to match the given data. Examples include Planck's original quantizing of radiation into discrete quanta, which turned out to be right. Another example is the Landau theory of 2nd-order phase transitions, where one builds a power-series expansion of the free energy in powers of something called the 'order parameter'. This is a total hack, but in many cases can adequately describe phase transitions (including superconductivity).
In fact, there are many kinds of physics theories, some termed 'macroscopic' in which case they're phenomonoligical, and describe what's going on, but don't adequately describe the 'physics' of the system. Then there's the microscopic theories that talk specifically about particle interactions, and follow directly from quantum mechanics, statistical mechanics, E&M, etc. The goal is to make these two approaches mesh.
For example, superconductivity could be described fairly well using the Ginzberg-Landau expansion, where the order parameter described above is complex, instead of real. Many things can be described this way, including Josephson Junctions and fluxoid quantization of superconducting loops. (Ginzberg just won the Nobel Prize in physics in 2003. Landau, if he were still alive, would have probably won it too, and it would have been his 2nd physics nobel prize). This approach worked fairly well, but physicists weren't sure why that was.
But then in 1957 Bardeen/Cooper/Schrieffer came up with the BCS theory of superconductivity, which explicitly describes how the electrons can pair up into Cooper pairs. Electrons want to repel, but in the right crystal lattice an electron-phonon-electron interaction (ie, a local distortion of the lattice) can produce an attractive interaction. BCS describe how this attraction comes about, how the energy gap forms, and how the electron pairs can carry a resistanceless supercurrent. BCS won the Nobel Prize in Physics in 1972.
This was microscopic vs macroscopic development of superconductivity. Two years later, physicist Gor'kov was able to show that the Ginzberg-Landau theory comes as a limiting case of the BCS theory. Hence, microscopic meets macroscopic, and everybody's happy.
So yes, physicists do look for something to fit the problem, but they don't just stop there. They also try to make those hacks or kludges match up directly from physical laws of the universe. That's what physics is about.
make world, not war
The event horizon of a black hole cannot shrink, except in the case of Hawking radiation, which is completely negligible for any stellar-sized black hole. In particular, if you put two black holes close to each other, their horizons will deform and grow in size. They will emit a bunch of gravitational (not Hawking) radiation in the process, because the final merged black hole is not as big as the sum of the two original holes (as measured in area).
Real particles can't tunnel outside the light cone (faster than light), which is what would be necessary to get out of the horizon. If you're talking about the vacuum production picture of Hawking radiation, there is a sense in which it can be interpreted in terms of tunneling.
Why should it explode? There is no limit to how much mass a black hole can contain. The more mass you dump in, the bigger it gets.
Not really.
No. Quantum entanglement can't be used to transmit information, regardless of whether there is a black hole around.
See also sections 9, 10, and 11 of this FTL FAQ.
This is where your mistake lies. The very foundation of the black hole is in it's mind boggling mass density. The absolute mass is important only in formation, because with too little mass gravitational forces are not able to compress matter enough to create the black hole.
You could get a black hole (complete with event horizon and Hawking radiation) by compressing earth into a radius less than about 9mm. Indeed, the less mass a black hole has, the smaller it is, and the larger the space curvature is on it's event horizon. Therefore all effects coming from space curvature are stronger for them, which also includes Hawking radiation. This especially means that finally black holes "explode": the more it radiates, the faster it gets smaller, and therefore it radiates even more in even shorter time scales, until it radiated it's complete mass away.
Of course, as soon as the black hole gets down to a size near the planck length (a mindboggling small length where quantum gravity effects are huge), we already know that all semiclassical reasoning must fail, therefore we cannot really say anything about what will happen at the last moment of a black hole, until we have a successfull theory of quantum gravity (or have watched black holes exploding, of course).
The Tao of math: The numbers you can count are not the real numbers.
One correction. Quantum entanglement can be used to transmit information, but only if you already have a classical (slower-than-light) information channel already running between the two places. Basically, if Alice and Bob each took half of an EPR pair then later if Alice has a qubit she wants to send Bob, there is a method by which she can perform operations and measurements and then send the results of the measurements to Bob who then acts on his half of the EPR pair which becomes the qubit that Alice wanted to send. There is no way to do this without the classical information channel though.
My only political goal is to see to it that no political party achieves its goals.