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Sunday, May 31, 2009

Gnome-o-gram: Endgame?

Take a look at the following charts, each covering recent months (you can click the images to obtain up-to-date charts from the original providers). The first chart shows the U.S. Dollar index, which measures the relative performance of the dollar against a basket of currencies including the Euro, Yen, British Pound, Canadian Dollar, Swiss Franc, and Swedish Kronor.


Ignore the detail and just take in the “big picture”, which is that since the Obama administration took office in January the U.S. dollar has been sliding, with an accelerating plunge in recent days (this analysis was written on 2009-05-31). The next chart shows the interest rate on the bellwether 10 year United States Treasury Note for the last six months.


Now this chart could almost be the mirror image of the first one: ever since January 2009 Treasury Note interest rates have been rising steadily, at an increasing rate recently. But usually, interest rates and currency strength move together; when a currency provides higher yield, investors sell other currencies to move their funds into it, hence bidding it up against lower yielding currencies. This is why central banks are forced to raise interest rates when their currencies begin to weaken.

But here we have the dollar simultaneously swooning in value at the same time interest rates are rising dramatically. What's going on here? Well, this kind of divergence is precisely what you see when investors are concerned about the stability of the currency and the safety of the principal they invest in it. As the perceived risk of not getting your money back, either directly due to a full or partial default, or stealthily by inflation reducing the value of the money you're repaid when the bond matures, investors will demand a higher rate of return to compensate them for the risk they're running, and this rising rate will not increase the value of the currency, as risk averse investors move their money to other currencies which are perceived to be safer, even though they pay a lower rate of interest.

In short, what we're seeing is the pattern you'd expect as a currency confidence crunch begins to take hold. Nobody is more attuned to the risk of inflation or default than investors in long term bonds, and buyers of Treasury paper are the most risk averse of all. So when these folks start to pull back, as appears to be happening, it's not a good sign for a government whose commitments require it to sell debt in amounts unprecedented in human history.

If this pattern continues, the risk of a destructive positive feedback loop increases in probability. Here's how it works. A government running enormous deficits and carrying a huge debt load spends correspondingly large sums on debt service (US$451 billion in the 2008 fiscal year). Now since the government is running deficits, the only way to repay holders of maturing bonds is to roll them over, selling new bonds. But the rollover occurs at the prevailing interest rate at the time, and if that rate has, say, doubled in the meanwhile, then the government's borrowing cost will be twice that for the new bond. This further increases the deficit, and with it the perceived risk, pushing interest rates still higher, and around and around we go. Eventually, the situation deteriorates to the point the Treasury can no longer find investors willing to buy its paper at all, or only at rates so high they cause the economy to collapse (since interest rates of all kinds rise when Treasury rates increase)—game over.

A government caught in this cycle may attempt to break it by instructing its central bank to step in and buy the newly issued debt, which amounts to printing money (indeed, the Federal Reserve has been doing precisely this in recent months). But as soon as investors see this happening, they expect inflation to set in once all of the newly-created money works its way through the python of the economy, and they start to bail out of the currency, driving down its value against others. But once a currency starts to slide, bond buyers will demand higher interest rates to compensate them for the expected depreciation of the currency. And so you have a falling currency, rising interest rates, difficulty financing ever-growing deficits which accelerate as debt service costs spike, and the central bank monetising the debt by creating money, which drives interest rates higher, crushing the economy, which causes tax receipts to fall, which further increases the deficits. How do you get out of this? Some countries never do.

The U.S. isn't there yet, but keep an eye on these two charts as the massive borrowing expected in the coming months occurs. If they continue to diverge and accelerate, it may be an indication that the endgame phase is underway. And remember that once a currency confidence crisis reaches the feedback loop stage, things can deteriorate with breathtaking speed. And note that every increase in the interest rate causes a slowdown in the economy. In particular, the “reset” rates of adjustable rate mortgages rise, which makes those holding them more likely to default, and less able to refinance as a new fixed rate mortgage will be at the new higher rate.

Other gnome-o-grams

Posted at 20:25 Permalink

Thursday, May 28, 2009

Reading List: Bacon: A Love Story

Lauer, Heather. Bacon: A Love Story. New York: William Morrow, 2009. ISBN 978-0-06-170428-4.
The author, who operates the Bacon Unwrapped Web site, just loves bacon. But who doesn't? I've often thought that a principal reason the Middle East produces so much more trouble than it consumes is that almost nobody there ever mellows out in that salty, fat-metabolising haze of having consumed a plate-full of The Best Meat Ever.

Bacon (and other salt-cured pork products) has been produced for millennia, and the process (which is easy do at home and explained here, if you're so inclined) is simple. And yet the result is so yummy that there are innumerable ways to use this meat in all kinds of meals. This book traces the history of bacon, its use in the cuisine of cultures around the world, and its recent breakout from breakfast food to a gourmet item in main courses and even dessert.

The author is an enthusiast, and her passion is echoed in the prose. But what would be amusing in an essay comes across as a bit too precious and tedious in a 200 page book—how many times do we need to be reminded that bacon is The Best Meat Ever? There are numerous recipes for baconlicious treats you might not have ever imagined. I'm looking forward to trying the macaroni and blue cheese with bacon from p. 153. I'm not so sure about the bacon peanut brittle or the bacon candy floss. Still, the concept of bacon as candy (after all, bacon has been called “meat candy”) has its appeal: one customer's reaction upon tasting a maple bacon lollipop was “Jesus got my letter!” For those who follow Moses, there's no longer a need to forgo the joys of bacon: thanks to the miracles of twenty-first century chemistry, 100% kosher Bacon Salt (in a rainbow of flavours) aims to accomplish its mission statement: “Everything should taste like bacon.” Try it on popcorn—trust me.

If you're looking for criticism of the irrational love of bacon, you've come to the wrong place. I don't eat a lot of bacon myself—when you only have about 2000 calories a day to work with, there's only a limited amount of porky ambrosia you can admit into your menu plan. This is a superb book which will motivate you to explore other ways to incorporate preserved pork bellies into your diet, and if that isn't happiness, what is? You will learn a great deal here about the history of pork products: now I finally understand the distinction between bacon, pancetta, and prosciutto.

Bacon lovers should be sure to bookmark The Bacon Show, a Web site which promises “One bacon recipe per day, every day, forever” and has been delivering just that for more than four years.

Posted at 01:23 Permalink

Friday, May 22, 2009

Reading List: He Leadeth Me

Ciszek, Walter J. with Daniel L. Flaherty. He Leadeth Me. San Francisco: Ignatius Press, [1973] 1995. ISBN 978-0-89870-546-1.
Shortly after joining the Jesuit order in 1928, the author volunteered for the “Russian missions” proclaimed by Pope Pius XI. Consequently, he received most of his training at a newly-established centre in Rome, where in addition to the usual preparation for the Jesuit priesthood, he mastered the Russian language and the sacraments of the Byzantine rite in addition to those of the Latin. At the time of his ordination in 1937, Stalin's policy prohibited the entry of priests of all kinds to the Soviet Union, so Ciszek was assigned to a Jesuit mission in eastern Poland (as the Polish-American son of first-generation immigrants, he was acquainted with the Polish language). When Germany and the Soviet Union invaded Poland in 1939 at the outbreak of what was to become World War II, he found himself in the Soviet-occupied region and subject to increasingly stringent curbs on religious activities imposed by the Soviet occupation.

The Soviets began to recruit labour brigades in Poland to work in factories and camps in the Urals, and the author and another priest from the mission decided to volunteer for one of these brigades, concealing their identity as priests, so as to continue their ministry to the Polish labourers and the ultimate goal of embarking on their intended mission to Russia. Upon arriving at a lumbering camp, the incognito priests found that the incessant, backbreaking work and intense scrutiny by the camp bosses made it impossible to minister to the other labourers.

When Hitler double crossed Stalin and invaded the Soviet Union in 1941, the Red Army was initially in disarray and Stalin apparently paralysed, but the NKVD (later to become the KGB) did what it has always done best with great efficiency: Ciszek, along with hundreds of other innocents, was rounded up as a “German spy” and thrown in prison. When it was discovered that he was, in fact, a Catholic priest, the charge was changed to “Vatican spy”, and he was sent to the Lubyanka, where he was held throughout the entire war—five years—most of it in solitary confinement, and subjected to the relentless, incessant, and brutal interrogations for which the NKVD never seemed to lack resources even as the Soviet Union was fighting for its survival.

After refusing to be recruited as a spy, he was sentenced to 15 years hard labour in Siberia and shipped in a boxcar filled with hardened criminals to the first of a series of camps where only the strongest in body and spirit could survive. He served the entire 15 years less only three months, and was then released with a restricted internal passport which only permitted him to live in specific areas and required him to register with the police everywhere he went. In 1947, the Jesuit order listed him as dead in a Soviet prison, but he remained on the books of the KGB, and in 1963 was offered as an exchange to the U.S. for two Soviet spies in U.S. custody, and arrived back in the U.S. after twenty-three years in the Soviet Union.

In this book, as in his earlier With God in Russia, he recounts the events of his extraordinary life and provides a first-hand look at the darkest parts of a totalitarian society. Unlike the earlier book, which is more biographical, in the present volume the author uses the events he experienced as the point of departure for a very Jesuit exploration of topics including the body and soul, the priesthood, the apostolate, the kingdom of God on Earth, humility, and faith. He begins the chapter on the fear of death by observing, “Facing a firing squad is a pretty good test, I guess, of your theology of death” (p. 143).

As he notes in the Epilogue, on the innumerable occasions he was asked, after his return to the U.S., “How did you manage to survive?” and replied along the lines explained herein: by consigning his destiny to the will of God and accepting whatever came as God's will for him, many responded that “my beliefs in this matter are too simple, even naïve; they may find that my faith is not only childlike but childish.” To this he replies, “I am sorry if they feel this way, but I have written only what I know and what I have experienced. … My answer has always been—and can only be—that I survived on the basis of the faith others may find too simple and naïve” (p. 199).

Indeed, to this reader, it seemed that Ciszek's ongoing discovery that fulfillment and internal peace lay in complete submission to the will of God as revealed in the events one faces from day to day sometimes verged upon a fatalism I associate more with Islam than Catholicism. But this is the philosophy developed by an initially proud and ambitious man which permitted him not only to survive the almost unimaginable, but to achieve, to some extent, his mission to bring the word of God to those living in the officially atheist Soviet Union.

A more detailed biography with several photographs of Father Ciszek is available. Since 1990, he has been a candidate for beatification and sainthood.

Posted at 22:04 Permalink

Monday, May 18, 2009

Reading List: The Silent Man

Berenson, Alex. The Silent Man. New York: G.P. Putnam's Sons, 2009. ISBN 978-0-399-15538-3.
This is a compelling page-turner in which the nightmare scenario of “loose nukes” falling into the hands of jihadi terrorists raises the risk of a nuclear detonation on U.S. soil. Only intrepid CIA agent (and loose cannon—heroes in books like this never seem to be of the tethered cannon variety) John Wells can put the pieces together before disaster strikes and possibly provokes consequences even worse than a nuclear blast.

The author has come up with a very clever scenario to get around many of the obvious objections to most plots of this kind. The characters of the malefactors are believable, and the suspense as the story unfolds is palpable; this is a book I did not want to either put down or have come to an end too quickly. Still, I have some major quibbles with the details, which I'll describe in the spoiler block below (I don't consider anything discussed a major plot spoiler, but better safe than sorry).

Spoiler warning: Plot and/or ending details follow.  
There are number of factual goofs (or invocations of artistic license, if you prefer). The Russian nuclear warheads stolen by the terrorists are said to be from SS-26 Iskander tactical missiles. Yet according to both the Russian military and NATO, this missile uses only conventional warheads. The warheads are said to have been returned for refurbishing due to damage from the missile's corrosive liquid fuel, but the Iskander is, in fact, a solid fuel missile

The premise of constructing an improvised gun assembly nuclear weapon from material from the secondary of a thermonuclear warhead seems highly implausible to me. (They couldn't use the fissile material from the primary because it is plutonium, which would predetonate in a gun design, and they can't fire the implosion mechanism of the primary without the permissive action link code, without which the implosion system will misfire, resulting in no nuclear yield.) Anyway, the terrorists plan to use highly enriched U-235 from the secondary in their gun bomb. The problem is that, unless I'm mistaken or the Russians use a very odd design in their bombs, there is no reason for a fusion secondary to contain anywhere near a critical mass of U-235 or, for that matter, any U-235 at all. In a Teller-Ulam design the only fissile material in the secondary is the uranium or plutonium “spark plug” used to heat the lithium deuteride fuel to a temperature where fusion can begin, but, even if U-235 is used, the quantity is much less than that required for a gun assembly bomb.

Even if the terrorists did manage to obtain sufficient U-235, I'm far from certain the bomb would have worked. They planned to use a gun assembly with a Russian SPG-9 recoilless rifle propelling the projectile into the target. They weld the tube of the bazooka directly to the steel tamper surrounding the target. But that won't work! The SPG-9 projectile is ejected from the tube by a small charge, but its rocket motor, which accelerates it to full velocity, does not ignite until the projectile is about twenty metres from the tube. So the projectile in the bomb would be accelerated only by the initial charge, which wouldn't impart anything like the velocity needed to avoid predetonation. Finally, the terrorists have no initiator: they just hope background radiation will generate a neutron to get things going. But if they aren't lucky, the whole assembly will be blown apart by the explosive charge of the SPG-9 round before nuclear detonation begins.

Now, if you don't know these details, or you're willing to ignore them (as I was), they don't in any way detract from what is a gripping story. There's no question that a small group of terrorists who came into possession of a sufficient quantity of highly enriched uranium could construct a simple gun bomb which would have a high probability of working on the first try. It's just that the scenario in the novel doesn't explain how they obtained a sufficient quantity, nor does it describe a weapon design which is likely to work.

Spoilers end here.  

Posted at 22:35 Permalink

Sunday, May 10, 2009

Reading List: Fat

Grant, Rob. Fat. London: Gollancz, 2006. ISBN 978-0-575-07820-8.
Every now and then, you have a really bad day. If you're lucky, you actually experience such days less frequently than you have nightmares about them (mine almost always involve trade shows, which demonstrates how traumatic that particular form of torture can be). The only remedy is to pick up the work of a master who shows you that whatever's happened to you is nothing compared to how bad a day really can be—this is such a yarn. This farce is in the fine tradition of Evelyn Waugh and Tom Sharpe, and is set in a future in which the British nanny state finally decides to do something about the “epidemic of obesity” which is bankrupting the National Health Service by establishing Well Farms, modelled upon that earlier British innovation, the concentration camp.

The story involves several characters, all of whom experience their own really bad days and come to interact in unexpected ways (you really begin to wonder how the author is going to pull it all together as the pages dwindle, but he does, and satisfyingly). And yet, as is usually the case in the genre, everything ends well for everybody.

This is a thoroughly entertaining romp, but there's also a hard edge here. The author skewers a number of food fads and instances of bad science and propaganda in the field of diet and nutrition and even provides a list of resources for those interested in exploring the facts behind the nonsense spouted by the “studies”, “reports”, and “experts” quoted in the legacy media.

Posted at 22:37 Permalink

Thursday, May 7, 2009

Reading List: The 10,000 Year Explosion

Cochran, Gregory and Henry Harpending. The 10,000 Year Explosion. New York: Basic Books, 2009. ISBN 978-0-465-00221-4.
“Only an intellectual could believe something so stupid” most definitely applies to the conventional wisdom among anthropologists and social scientists that human evolution somehow came to an end around 40,000 years ago with the emergence of modern humans and that differences among human population groups today are only “skin deep”: the basic physical, genetic, and cognitive toolkit of humans around the globe is essentially identical, with only historical contingency and cultural inheritance responsible for different outcomes.

To anybody acquainted with evolutionary theory, this should have been dismissed as ideologically motivated nonsensical propaganda on the face of it. Evolution is driven by changes and new challenges faced by a species as it moves into new niches and environments, adapts to environmental change, migrates and encounters new competition, and is afflicted by new diseases which select for those with immunity. Modern humans, in their expansion from Africa to almost every habitable part of the globe, have endured changes and challenges which dwarf those of almost any other metazoan species. It stands to reason, then, that the pace of human evolution, far from coming to a halt, would in fact accelerate dramatically, as natural selection was driven by the coming and going of ice ages, the development of agriculture and domestication of animals, spread of humans into environments inhospitable to their ancestors, trade and conquest resulting in the mixing of genes among populations, and numerous other factors.

Fortunately, we're lucky to live in an age in which we need no longer speculate upon such matters. The ability to sequence the human genome and compare the lineage of genes in various populations has created the field of genetic anthropology, which is in the process of transforming what was once a “soft science” into a thoroughly quantitative discipline where theories can be readily falsified by evidence in the genome. This book has the potential of creating a phase transition in anthropology: it is a manifesto for the genomic revolution, and a few years from now anthropologists who ignore the kind of evidence presented here will be increasingly forgotten, publishing papers nobody reads because they neglect the irrefutable evidence of human history we carry in our genes.

The authors are very ambitious in their claims, and I'm sure that some years from now they will be seen to have overreached in some of them. But the central message will, I am confident, stand: human evolution has dramatically accelerated since the emergence of modern humans, and is being driven at an ever faster pace by the cultural and environmental changes humans are incessantly confronting. Further, human history cannot be understood without first acknowledging that the human populations which were the actors in it were fundamentally different. The conquest of the Americas by Europeans may well not have happened had not Europeans carried genes which protected them against the infectuous diseases they also carried on their voyages of exploration and conquest. (By some estimates, indigenous populations in the Americas fell to 10% of their pre-contact levels, precipitating societal collapse.) Why do about half of all humans on Earth speak languages of the Indo-European group? Well, it may be because the obscure cattle herders from the steppes who spoke the ur-language happened to evolve a gene which made them lactose tolerant throughout adulthood, and hence were able to raise cattle for dairy products, which is five times as productive (measured by calories per unit area) as raising cattle for meat. While Europeans' immunity to disease served them well in their conquest of the Americas, their lack of immunity to diseases endemic in sub-Saharan Africa (in particular, falciparum malaria) rendered initial attempts colonise that region disastrous.

The authors do not hesitate to speculate on possible genetic influences on events in human history, but their conjectures are based upon published genetic evidence, cited from primary sources in the extensive end notes. A number of these discussions may lead to the sound of skulls exploding among those wedded to the dominant academic dogma. The authors suggest that some of the genes which allowed modern humans emerging from Africa to prosper in northern climes were the result of cross-breeding with Neanderthals; that just as domestication of animals results in neoteny, domestication of humans in agricultural and the consequent state societies has induced neotenous changes in “domesticated humans” which result in populations with a long history of living in agricultural societies adapting better to modern civilisation than those without that selection in their genetic heritage, and that the unique experience of selection for success in intellectually demanding professions and lack of interbreeding resulted in the emergence of the Ashkenazi Jews as a population whose mean intelligence exceeds that of all other human populations (as well as a prevalence of genetic diseases which appear linked to biochemical factors related to brain function).

There's an odd kind of doublethink present among many champions of evolutionary theory. While invoking evolution to explain even those aspects of the history of life on Earth where doing so involves what can only be called a “leap of faith”, they dismiss the self-evident consequences of natural selection on populations of their own species. Certainly, all humans constitute a single species: we can interbreed, and that's the definition. But all dogs and wolves can interbreed, yet nobody would say that there is no difference between a Great Dane and a Dachshund. Largely isolated human populations have been subjected to unique selective pressures from their environment, diet, diseases, conflict, culture, and competition, and it's nonsense to argue that these challenges did not drive selection of adaptive alleles among the population.

This book is a welcome shot across the bow of the “we're all the same” anthropological dogma, and provides a guide to the discoveries to be made as comparative genetics lays a firm scientific foundation for anthropology.

Posted at 20:30 Permalink

Monday, May 4, 2009

Reading List: The Black Hole War

Susskind, Leonard. The Black Hole War. New York: Little, Brown, 2008. ISBN 978-0-316-01640-7.
I hesitated buying this book for some months after its publication because of a sense there was something “off” in the author's last book, The Cosmic Landscape (March 2006). I should learn to trust my instincts more; this book treats a fascinating and important topic on the wild frontier between general relativity and quantum mechanics in a disappointing, deceptive, and occasionally infuriating manner.

The author is an eminent physicist who has made major contributions to string theory, the anthropic string landscape, and the problem of black hole entropy and the fate of information which is swallowed by a black hole. The latter puzzle is the topic of the present book, which is presented as a “war” between Stephen Hawking and his followers, mostly general relativity researchers, and Susskind and his initially small band of quantum field and string theorists who believed that information must be preserved in black hole accretion and evaporation lest the foundations of physics (unitarity and the invertibility of the S-matrix) be destroyed.

Here is a simple way to understand one aspect of this apparent paradox. Entropy is a measure of the hidden information in a system. The entropy of gas at equilibrium is very high because there are a huge number of microscopic configurations (position and velocity) of the molecules of the gas which result in the same macroscopic observables: temperature, pressure, and volume. A perfect crystal at absolute zero, on the other hand, has (neglecting zero-point energy), an entropy of zero because there is precisely one arrangement of atoms which exactly reproduces it. A classical black hole, as described by general relativity, is characterised by just three parameters: mass, angular momentum, and electrical charge. (The very same basic parameters as elementary particles—hmmmm….) All of the details of the mass and energy which went into the black hole: lepton and baryon number, particle types, excitations, and higher level structure are lost as soon as they cross the event horizon and cause it to expand. According to Einstein's theory, two black holes with the same mass, spin, and charge are absolutely indistinguishable even if the first was made from the collapse of a massive star and the second by crushing 1975 Ford Pintos in a cosmic trash compactor. Since there is a unique configuration for a given black hole, there is no hidden information and its entropy should therefore be zero.

But consider this: suppose you heave a ball of hot gas or plasma—a star, say—into the black hole. Before it is swallowed, it has a very high entropy, but as soon as it is accreted, you have only empty space and the black hole with entropy zero. You've just lowered the entropy of the universe, and the Second Law of Thermodynamics says that cannot ever happen. Some may argue that the Second Law is “transcended” in a circumstance like this, but it is a pill which few physicists are willing to swallow, especially since in this case it occurs in a completely classical context on a large scale where statistical mechanics obtains. It was this puzzle which led Jacob Bekenstein to propose that black holes did, in fact, have an entropy which was proportional to the area of the event horizon in units of Planck length squared. Black holes not only have entropy, they have a huge amount of it, and account for the overwhelming majority of entropy in the universe. Stephen Hawking subsequently reasoned that if a black hole has entropy, it must have temperature and radiate, and eventually worked out the mechanism of Hawking radiation and the evaporation of black holes.

But if a black hole can evaporate, what happens to the information (more precisely, the quantum state) of the material which collapsed into the black hole in the first place? Hawking argued that it was lost: the evaporation of the black hole was a purely thermal process which released none of the information lost down the black hole. But one of the foundations of quantum mechanics is that information is never lost; it may be scrambled in complex scattering processes to such an extent that you can't reconstruct the initial state, but in principle if you had complete knowledge of the state vector you could evolve the system backward and arrive at the initial configuration. If a black hole permanently destroys information, this wrecks the predictability of quantum mechanics and with it all of microscopic physics.

This book chronicles the author's quest to find out what happens to information that falls into a black hole and discover the mechanism by which information swallowed by the black hole is eventually restored to the universe when the black hole evaporates. The reader encounters string theory, the holographic principle, D-branes, anti de Sitter space, and other arcana, and is eventually led to the explanation that a black hole is really just an enormous ball of string, which encodes in its structure and excitations all of the information of the individual fundamental strings swallowed by the hole. As the black hole evaporates, little bits of this string slip outside the event horizon and zip away as fundamental particles, carrying away the information swallowed by the hole.

The story is told largely through analogies and is easy to follow if you accept the author's premises. I found the tone of the book quite difficult to take, however. The word which kept popping into my head as I made my way through was “smug”. The author opines on everything and anything, and comes across as scornful of anybody who disagrees with his opinions. He is bemused and astonished when he discovers that somebody who is a Republican, an evangelical Christian, or some other belief at variance with the dogma of the academic milieu he inhabits can, nonetheless, actually be a competent scientist. He goes on for two pages (pp. 280–281) making fun of Mormonism and then likens Stephen Hawking to a cult leader. The physics is difficult enough to explain; who cares about what Susskind thinks about everything else? Sometimes he goes right over the top, resulting in unseemly prose like the following.

Although the Black Hole War should have come to an end in early 1998, Stephen Hawking was like one of those unfortunate soldiers who wander in the jungle for years, not knowing that the hostilities have ended. By this time, he had become a tragic figure. Fifty-six years old, no longer at the height of his intellectual powers, and almost unable to communicate, Stephen didn't get the point. I am certain that it was not because of his intellectual limitations. From the interactions I had with him well after 1998, it was obvious that his mind was still extremely sharp. But his physical abilities had so badly deteriorated that he was almost completely locked within his own head. With no way to write an equation and tremendous obstacles to collaborating with others, he must have found it impossible to do the things physicists ordinarily do to understand new, unfamiliar work. So Stephen went on fighting for some time. (p. 419)
Or, Prof. Susskind, perhaps it's that the intellect of Prof. Hawking makes him sceptical of arguments based a “theory” which is, as you state yourself on p. 384, “like a very complicated Tinkertoy set, with lots of different parts that can fit together in consistent patterns”; for which not a single fundamental equation has yet been written down; in which no model that remotely describes the world in which we live has been found; whose mathematical consistency and finiteness in other than toy models remains conjectural; whose results regarding black holes are based upon another conjecture (AdS/CFT) which, even if proven, operates in a spacetime utterly unlike the one we inhabit; which seems to predict a vast “landscape” of possible solutions (vacua) which make it not a theory of everything but rather a “theory of anything”; which is formulated in a flat Minkowski spacetime, neglecting the background independence of general relativity; and which, after three decades of intensive research by some of the most brilliant thinkers in theoretical physics, has yet to make a single experimentally-testable prediction, while demonstrating its ability to wiggle out of almost any result (for example, failure of the Large Hadron Collider to find supersymmetric particles).

At the risk of attracting the scorn the author vents on pp. 186–187 toward non-specialist correspondents, let me say that the author's argument for “black hole complementarity” makes absolutely no sense whatsoever to this layman. In essence, he argues that matter infalling across the event horizon of a black hole, if observed from outside, is disrupted by the “extreme temperature” there, and is excited into its fundamental strings which spread out all over the horizon, preserving the information accreted in the stringy structure of the horizon (whence it can be released as the black hole evaporates). But for a co-moving observer infalling with the matter, nothing whatsoever happens at the horizon (apart from tidal effects whose magnitude depends upon the mass of the black hole). Susskind argues that since you have to choose your frame of reference and cannot simultaneously observe the event from both outside the horizon and falling across it, there is no conflict between these two descriptions, and hence they are complementary in the sense Bohr described quantum observables.

But, unless I'm missing something fundamental, the whole thing about the “extreme temperature” at the black hole event horizon is simply nonsense. Yes, if you lower a thermometer from a space station at some distance from a black hole down toward the event horizon, it will register a diverging temperature as it approaches the horizon. But this is because it is moving near the speed of light with respect to spacetime falling through the horizon and is seeing the cosmic background radiation blueshifted by a factor which reaches infinity at the horizon. Further, being suspended above the black hole, the thermometer is in a state of constant acceleration (it might as well have a rocket keeping it at a specified distance from the horizon as a tether), and is thus in a Rindler spacetime and will measure black body radiation even in a vacuum due to the Unruh effect. But note that due to the equivalence principle, all of this will happen precisely the same even with no black hole. The same thermometer, subjected to the identical acceleration and velocity with respect to the cosmic background radiation frame, will read precisely the same temperature in empty space, with no black hole at all (and will even observe a horizon due to its hyperbolic motion).

The “lowering the thermometer” is a completely different experiment from observing an object infalling to the horizon. The fact that the suspended thermometer measures a high temperature in no way implies that a free-falling object approaching the horizon will experience such a temperature or be disrupted by it. A co-moving observer with the object will observe nothing as it crosses the horizon, while a distant observer will see the object appear to freeze and wink out as it reaches the horizon and the time dilation and redshift approaches infinity. Nowhere is there this legendary string blowtorch at the horizon spreading out the information in the infalling object around a horizon which, observed from either perspective, is just empty space.

The author concludes, in a final chapter titled “Humility”, “The Black Hole War is over…”. Well, maybe, but for this reader, the present book did not make the sale. The arguments made here are based upon aspects of string theory which are, at the moment, purely conjectural and models which operate in universes completely different from the one we inhabit. What happens to information that falls into a black hole? Well, Stephen Hawking has now conceded that it is preserved and released in black hole evaporation (but this assumes an anti de Sitter spacetime, which we do not inhabit), but this book just leaves me shaking my head at the arm waving arguments and speculative theorising presented as definitive results.

Posted at 23:48 Permalink