Breaking News
Loading...
Friday 21 December 2012

Info Post
Jennifer Ouellette wrote a nice piece on black hole firewalls for the Simons Foundation and for Scientific American:
Black Hole Firewalls Confound Theoretical Physicists (via Synch).
Well, more precisely, it's nice and informative if you assume that her task was to uncritically promote the views of Joe Polchinski, Leonard Susskind, Raphael Bousso, and a few others. From a more objective viewpoint, the article's main message is wrong and the text misinterprets the state of the research, too.



Somewhat but not entirely typical Czech skeptical and blasphemous attitude to Christmas. Xindl X: Christmas Eve arrived when I guzzled at home. He feels like being in shackles, much like his Christmas tree. He also has a tip and hanging balls. No reason to celebrate another lost year, he wants to return to the Saturnalia again. By the New Year, he switched from guzzling to light drugs.

Over the last decade or so, my great respect for some of the most famous names in high-energy physics was diminishing and this trend has become undeniable by now. It seems to me that my previous worries about the apparent deterioration of meritocracy within the field have turned out to be a tangible reality.




Oullette explains what a black hole is, that nothing should happen at the event horizon, that it Hawking radiates, how the Hawking radiation may be thought of, and that various arguments leading to information loss and other undesirable things have been identified as incorrect once the black hole complementarity was appreciated.

However, when it comes to the AMPS thought experiment, it just uncritically parrots the wrong statements by Polchinski et al.:
The interior (A) and the near exterior (B) have to be almost maximally entangled for the space near the horizon to feel empty; the near exterior (B) is almost maximally entangled with some qubits inside the Hawking radiation (C) because the Hawking radiation's ability to entangle the infalling and outgoing qubits. Because of the monogamy of the entanglement (at most one maximum entanglement may incorporate (B) at the same time), some assumptions have to be invalid. The unitarity should be preserved which means that the A-B entanglement has to be sacrificed and the space near the horizon isn't empty: it contains a firewall that burns the infalling observer.
That may sound good but, as repeatedly explained on this blog, this argument is wrong for a simple reason. The degrees of freedom in (A) and those in (C) aren't independent and non-overlapping. It is the very point of the black hole complementarity that the degrees of freedom in (A) are a scrambled subset of those in (C). The degrees of freedom in (A) are just another way to pick observable, coarse-grained degrees of freedom and "consistent histories" within the same Hilbert space. So the entanglement of (B) with "both" (A) and (C) isn't contradictory in any sense: it's the entanglement with the same degrees of freedom described twice.

Among the 25 papers that currently cite the original firewall paper by AMPS, this point is understood by a majority of the papers. A majority of them does explain that AMPS is wrong and they add various things and more detailed descriptions of this point – and by the details, they largely differ from the other papers.

But despite these papers' being not only right but belonging to a majority and despite Scientific American's celebration of "majorities" in other disciplines of science, you won't learn about the very existence of this majority at all. You won't hear about a single argument explaining why the AMPS reasoning is invalid. Even if you disagreed that e.g. Raju and Papadodimas understand the black hole information issues more correctly than Polchinski does, you should still agree that Joe's indication that these Harvard-trained physicists' 72-page-long work (and other papers) doesn't exist at all is disrespectful, to say the least. In fact, you're actively told by Oullette that no such argument exists! And you surely don't learn about any work that is more important and more valuable than AMPS that AMPS couldn't even ask because they already made a grave mistake in the first steps. More seriously, I think it's not really Jennifer's fault.



The most played video of 2012, Psy: Gangnam Style by a South Korean rapper, has collected more than one billion views. The version above contains some more familiar and friendly characters than the unknown South Korean non-scientist.

It seems clear to me that this imbalanced perspective was incorporated to the article by the main "informers" among the scientists who communicated with Jennifer. This conclusion of mine partly boils down to the amazing self-glorification of Joe Polchinski in particular. So we're learning that if there's a mistake, the mistake is not obvious, AMPS is a "mighty fine paradox" that is "destined to join the ranks of classic thought experiments in physics" and it's the "most exciting thing that happened since [Bousso] entered physics". Holy cow. The mistake is obvious. AMPS simply assume that complementarity can't hold by insisting on separate parts of the wave function that are responsible for observations inside and outside. That's a wrong assumption, so it's not shocking that various corollaries such as the "firewall" at the horizon are wrong, too. This wrong assumed denial of complementarity is as wrong as the assumption that simultaneity has to be absolute – an assumption made by those who "debunk" Einstein's relativity; the error is in step 1 and means that they just didn't understand the original insights.

I am grateful to remember some of the times when the progress in theoretical physics was so intense and the process of discovery of manifestly right new insights was so effective that wrong papers would simply disappear and were ignored. Individual great contributors were celebrated but the number of "manhours" invested into verification and extension of important results was so high that it wasn't really possible for a group of people – not even the most famous ones – to deliberately spread wrong results. But gradually, over the following years, some physicists eager to make "new revolutions" entered the mode in which they became happy to publish revolutionary claims even if they had to know that they were incorrect or at least they required a great amount of skewed self-brainwashing to be believed.

Moreover, and this is even more worrisome, many famous physicists apparently decided that they don't want the real progress in physics to continue and they just want to use their relative fame to convince their environment that whatever stupidity they are writing papers about right now is the most important thing happening in the field. And they seemingly decided they wanted to be the last golden generation. I feel that many of those folks don't want the next generation to emerge and thrive at all. The remarkable omission – well, downright denial – of some of the great work in Oullette's article forces me to adopt this conclusion.

And the omitted work isn't great just by some subjective evaluation of the content. It's also written by some of the greatest minds of their generation that have been shaped at the greatest universities, that have joined faculties of other universities in some cases by now, and that have proved (usually already as students) their ability to understand everything that Polchinski and others have ever written and their ability to find comparable new insights and go beyond them, too. But when you look at magazines such as Scientific American, it seems clear that there's pretty much no one left in the physics establishment – and in the journalistic and P.R. environment surrounding the physics community – who is interested in genuine progress anymore.

What I no longer see in the physics community is the passion for the truth, at least among the folks who are most visible in the media. I feel that the most competent folks working on similar research are social-engineered from above and from outside to languish and remain invisible. It seems to me that the achieved physicists are gradually switching to the production of random, cheap, and wrong ideas of the type that "everyone may understand" and their unquestionable defense and promotion.

Fifteen years ago, 't Hooft would start to write lots of preposterous papers about hydrodynamic models replacing quantum mechanics and all this amazing junk. At that time, I didn't care because I saw a thriving community that didn't have to respond to those things because it was busy with genuine advances. This thriving community had leaders – some of the very names described negatively in this blog entry surely belonged to it.

But whether or not it is a viable strategy for the "real deal" physicists to ignore the bad apples is a subtle question that depends on the balance of influence at various places. I never liked the anthropic hype but its influence on the community seemed tolerable because there existed natural authorities that were defending the kind of research I would consider valuable who could have been heard, and so on.

Sometime around 2006 when hardcore crackpots such as Lee Smolin and Peter Woit "charmed" the media with their uninterrupted stream of shameful and hostile lies, I decided that the balance had been almost irreversibly destroyed in favor of the bad apples. At that time, I was scared to see that the only place in which most of the top physicists had the courage to even mention the basic fact that Lee Smolin is a crackpot was a closed room somewhere at the KITP in Santa Barbara. Journalist George Johnson was stunned because it was the first time when he learned that Lee Smolin was a crank at all; this elementary fact had to be classified. The likes of Smolin have literally hijacked the environment of science journalism and the part of public and the scientific public that is getting information from it. It was a highly unhealthy development.

It didn't end up with the general spitting on the greatest advances in theoretical physics of the last 30 years. Many people, including those whom you would surely not count as Smolin's soulmates, also began to invent crackpot theories – or at least not too justified theories whose main point is to pompously reject some important principles of physics, whether or not they have sufficient evidence to do so. So Petr Hořava came with his non-relativistic "Lifshitz" models of gravity. That was still OK. Erik Verlinde's "gravity as an entropic force" was of course much worse.

AMPS isn't as bad or as obviously wrong as "gravity as an entropic force" but it's still wrong and what's worse about it is that it is pushed by some of the names that are more famous than Erik Verlinde's name. None of those bad apples would really destroy an otherwise healthy research community but the main problem I see is that the bad apples can no longer be efficiently wrestled with. Or it's not happening. It doesn't look like anyone cares at all. Instead, it seems to me that people are defending their subjective and increasingly non-quantitative (and often downright wrong) ideas and these people's connectedness to the journalists and other folks outside the research community itself and the related populism – instead of the scientific evaluation by those who actually understand the things as experts – have become the key determinants of success.

Yuri Milner showed it's possible to change the balance in the good direction, too. Still, it's questionable how much it helps the current research. The average breakthroughs celebrated by his Fundamental Physics Prize are about 20 years old. Of course, one could say that it's because those advances that took place 20 or 30 years ago are more important than most advances in the last 5 or 10 years. Maybe, the Milner Prize will inevitably exhaust the great contributors from the 1980s or 1990s and it will have to switch to very recent research. When it happens, I hope it will still be decided by similar people and according to similar criteria.

Even if one concludes that the advances done several decades ago are more important than those found in the latest 5 or 10 years, and I am inclined to agree, it's no excuse for physicists to abandon meritocracy and to transform their fields into a dumping ground of garbage. Instead, it's their duty to meticulously continue to produce new research and filter the research offered by others so that the best seeds are found and allowed to thrive, whether these seeds are larger or smaller than the seeds found several decades ago.

Incidentally, George Musser presented Polchinski's point of view on his SciAm blog equally uncritically a week ago, too. Too bad that no one is trying to find out what some other famous folks – e.g. Witten – have to say about those matters.

0 comments:

Post a Comment