Sunday, May 31, 2015

Dear Mr. Brown

As a science fiction writer, I grant you a lot of latitude, but really. You have your spaceship jump nine light years and the captain/pilot/navigator sees only an imperceptible change in the positions of the stars? Pulleeze! The night sky would be nearly unrecognizable nine light years from Earth in any direction. Many of the brightest stars are less than twenty light years away and nearly all are less than 100 light years away.

Of the twenty-six brightest stars, only Deneb, Betelgeuse, and Rigel are far enough away (1500 and 1400 light years) that they would be shifted by only a couple of degrees.

If you were writing about pirates on the Spanish Main I would expect you to know that Cuba was farther from Madrid than Barcelona is. Since you write about interstellar adventure, you ought to have some clue as to how stars are distributed.

Distances to brightest stars.

Crimes Against Books: Amazon

The Amazon Kindle versions of lots of science books are terrible. This is because the super-sucky software cannot handle equations or figures appropriately. It's like postscript was never invented. Equations are frequently reduced to tiny images - pictures of equations rather than actual equations. Inline equations fare even worse - exponents are lost, Greek letters become inequivalent Roman ones, subscripts disappear.

It's really something of a tragedy that Amazon has captured the e-reader market with its incompetent page rendering. I wonder if there are any plans to fix it.


Via Alex Tabarrok of MR, a view from Mountain View of the self-driving car:

I see no less than 5 self-driving cars every day. 99% of the time they’re the Google Lexuses, but I’ve also seen a few other unidentified ones (and one that said BOSCH on the side). I have never seen one of the new “Google-bugs” on the road, although I’ve heard they’re coming soon. I also don’t have a good way to tell if the cars were under human control or autonomous control during the stories I’m going to relate.

Anyway, here we go: Other drivers don’t even blink when they see one. Neither do pedestrians – there’s no “fear” from the general public about crashing or getting run over, at least not as far as I can tell.

Google cars drive like your grandma – they’re never the first off the line at a stop light, they don’t accelerate quickly, they don’t speed, and they never take any chances with lane changes (cut people off, etc.).

- See more at:

Horror Story

Gardiner Harris, writing in The New York Times Sunday Review, tells the story of the horrors of air pollution in New Delhi, India. Beijing is infamous for its murderous killer smog, but it seems that New Delhi is a great deal worse. Harris's article is entitled "Holding Your Breath in India" but a more descriptive title might be "How I inflicted Child Abuse Resulting in Severe Permanent Damage in Pursuit of the Story."

New Delhi

FOR weeks the breathing of my 8-year-old son, Bram, had become more labored, his medicinal inhaler increasingly vital. And then, one terrifying night nine months after we moved to this megacity, Bram’s inhaler stopped working and his gasping became panicked.

My wife called a friend, who recommended a private hospital miles away. I carried Bram to the car while my wife brought his older brother. India’s traffic is among the world’s most chaotic, and New Delhi’s streets are crammed with trucks at night, when road signs become largely ornamental. We undertook one of the most frightening journeys of our lives, with my wife in the back seat cradling Bram’s head.

When we arrived, doctors infused him with steroids (and refused to provide further treatment until a $1,000 charge on my credit card went through). A week later, Bram was able to return home.


We gradually learned that Delhi’s true menace came from its air, water, food and flies. These perils sicken, disable and kill millions in India annually, making for one of the worst public health disasters in the world. Delhi, we discovered, is quietly suffering from a dire pediatric respiratory crisis, with a recent study showing that nearly half of the city’s 4.4 million schoolchildren have irreversible lung damage from the poisonous air.

It's a grim but fascinating story. Mostly it is about his family's experience, but more generally about how much damage the megacity can do to its inhabitants. India has always been a dangerous place, but in crucial ways economic development and especially population growth have made it far more so.

Meanwhile, coal production in India, a government monopoly, has increased more that twenty-fold since 1950, and continues to increase exponentially.

And some people still think Malthus has been refuted.

Saturday, May 30, 2015


I am kind of a fan of the Princeton physics in a nutshell series. The first one I bought was Tony Zee's Quantum Field Theory in a Nutshell. I've bought five more in the meantime, including one electronic version (Einstein Gravity in a Nutshell, also by Zee).

The thing is, I kind of like the way the matching covers of the other four line up on my bookshelf. I don't find electronic textbooks easy to read, though Princeton's books seem better than those from Cambridge. So anyway, is the extra two hundred pages in the second edition of QFT worth it, especially if I consider the added benefit of the matching cover?

August 1914 = June 2015 ?

Paul Krugman:

There’s an odd summer-of-1914 feel to the current state of the Greek crisis. While some of the main players are, rightly, desperate to find a way to head off Grexit and all it entails, others – on the creditor as well as the debtor side — seem not just resigned to collapse but almost as if they’re welcoming the prospect, the way, a century ago, far too many Europeans actually seemed to welcome the end of messy, frustrating diplomacy and the coming of open war.

Is there still a way out? There should be. As I and others have been saying for a while, the arithmetic is actually quite clear: Greece cannot run a primary deficit, it cannot be forced to run a large primary surplus, so a small primary surplus is the obvious solution and better for all concerned than euro exit.

Krugman's argument is that there is no way for Greece to actually pay all that it owes, so that it would be better for all if most of the Greek debt were written off and Greece was to just make mainly symbolic payments rather than write off the Greek debt, definitely blow up the Greek economy and quite possibly blow up the European economy with it.

But thus do I counsel you, my friends: distrust all in whom the impulse to punish is powerful! They are people of bad race and lineage; out of their countenances peer the hangman and the sleuth-hound. Distrust all those who talk much of their justice!

Friedrich Nietzsche...............Thus Spoke Zarathustra

Friday, May 29, 2015

Upstart Wines

I rarely drink wine. When I drink at all, it's usually beer. I usually don't care for the taste of wine, and wines, especially red wines, provoke my asthma. Also, despite my bulk, I have low alcohol tolerance, so that even one drink usually gives me a slight buzz. In any case, serious wine drinkers speak a language that I don't understand and that doesn't usually interest me.

So its really pretty odd that I found myself fascinated by this New York Times Magazine article by Bruce Shoenfeld. He begins:

A band of upstart winemakers is trying to redefine what California wine should taste like — and enraging America’s most famous oenophile in the process.

It seems that the upstarts have rather different ideas about what makes a suitable wine than Robert M. Parker, the founder of The Wine Advocate and reigning world wine guru. As I say, wines don't interest me, but people always do, and one of the more fascinating traits of H. sapiens with time and money on its hands is to become infatuated by a topic or facet of existence. Wines, like Dungeons and Dragons, Motorcycles, and cult novelists seems to be one of those topics.

You might like the story if you like wine or just find weird people fun.

Thursday, May 28, 2015

Solar Dreams

For pessimists only. As of 2013, solar power provided about 0.24% of all energy consumed in the world.

Book Review: Magnificent Delusions

Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding, Nov 5, 2013 by Husain Haqqani is a detailed description of the relations between Pakistan and the US from the birth of Pakistan in 1947 to nearly the present. There are plenty of delusions, to be sure, but I'm not so sure that they are magnificent - more like delusions of magnificence.

From its founding, Pakistan sold itself to the US as a bulwark against Communism, but in fact spent nearly all of the aid the US has lavished on it - some $67 billion in 2011 dollars - on an expensive military aimed almost exclusively at India. Pakistan was founded so that Indian Muslims could be independent of Hindu rule, and its primary tool in unifying its own diverse cultures has always been fanning the flames of Muslim fanaticism and anti-India rage. One pretext for that rage was the fact that in the partition India managed to grab Jammu and Kashmir, a region with a large Muslim population that Pakistan wanted. Many of the the Indian-Pakistani conflicts since have focused on that region, which has long been divided by a less than peaceful line of control.

When the British ruled India, they imagined that the Indians were divided into martial and non martial races, and they recruited their India's Army mainly from the presumably martial races of the Punjab. No doubt this idea fed the delusions of the Pakistani officer class, who in turn imagined that they were better fighters than the Indians and could defeat them in battle as a result. Repeated defeats taught them nothing but denial, defiance and resentment. Instead of building its economy, Pakistan spent lavishly (mostly with US and Saudi money) on building their Army.

While India was the prime target of Pakistani propaganda and rage, the US was not far behind. Pakistan was a bitter and resentful supplicant, with one hand holding out the begging bowl while the other cultivated scurrilous accusations against its benefactor. This was more a tactic than an accident, since the generals who have always controlled Pakistan claimed that if they didn't get more aid, they would face the anger of the Islamic street - the very anger that they assiduously cultivated.

If Pakistan's delusion that it could defeat India with an Army paid for from abroad is easily dismissed, how can we explain the fact that the US repeatedly took the sucker's bet that it could buy Pakistani cooperation with money and weapons? It's complicated. One factor is that US administrations usually like to start anew, frequently ignoring the hard won lessons of the past.

Under the Eisenhower and Nixon administrations, the US was preoccupied with building a firewall against Communism, and anybody who claimed anti-Communism could qualify for a merit badge. Socialist and Neutralist India, by contrast, was automatically suspect. Kennedy and Johnson were more suspicious of Pakistan, but were preoccupied with other problems, especially Vietnam. Carter was similarly enmeshed with Iran, but he, and to a much greater degree Reagan, saw a chance to defeat Russia in Afghanistan, pouring in the money that built the Pakistani Interservice Intelligence (ISI) organization, the Taliban, and a host of other terrorist organizations fostered by the ISI.

After 9/11, Bush junior confronted Pakistan with an ultimatum - be with us or against us. Pakistan agreed, but did not stop cheating. Both Clinton and Obama offered Pakistan a lot if they would only mend their evil ways and concentrate on building a country, but the generals persisted in their fanaticism. Obama in particular warned Pakistan that if a terrorist attack against the US (like that against India by Lakshar-e-Taibba) succeeded, nobody could prevent terrible retribution.

Last I heard, the US and Pakistan continue to pursue their drone operations against the Taliban, operations in which the ISI cooperated, but fulminates against in the press.

So how did I like the book? It's packed with information, backed up by many dozens of pages of endnotes, and rather well written, by a Pakistani professor in exile who was part of several Pakistani governments. This should not be confused with a dispassionate history by an outsider - it is a history, but one told by someone who feels that his country has repeatedly been betrayed by its military, a military which has become a cancer on the country. The US does not escape blame either. The military and the ISI fed on our largesse, and could not have assumed their fully malignant form without it.

My extended comments on the book can be found here.

Wednesday, May 27, 2015

Collision Hazards

The largest ocean going ships are about half a million tons. I would expect that any interstellar ships we or others might build would have to be at least that size in order to survive a journey lasting decades or centuries. Let's estimate a million tonnes - 10^9 kg - roughly twice the mass of the supertanker the Seawise Giant.

I remember the first time I saw a piece of armor plate that had been struck by a hypervelocity projectile. Even though the projectile was only a bit larger than a beebee, it had drilled a hole right through two inches of armor plate. Lower velocity projectiles spread their energy over larger areas. The operative factor is the speed of sound. If the projectile is moving significantly faster than the speed of sound in the target material, there isn't enough time for the forces to be transmitted laterally, and the projectile just keeps boring a hole until it has piled up enough mass in front of it to slow the whole procession, including the shock wave at the front, below the speed of sound.

It's a bit more complicated than that of course.

Suppose you had a large interstellar space craft moving a something like half the speed of light. The kinetic energy would be pretty large:

m*c^2(gamma - 1), where gamma = 1/sqrt(1-v^2/c^2) = 1/sqrt(3/4) = 1.1555, so that available kinetic energy is 1.4 * 10^16 J/kg, or 1.4 * 10^25 J for a million tonne behemoth like that described in the first paragraph. That amounts to the equivalent of 3 billion megatons of TNT - not enough to blow a planet to bits, death star style, but possibly enough to blast a hole right through it. So you might not want to aim your interstellar ship directly at a habitable planet, just in case you had trouble slowing down.

Monday, May 25, 2015

Who Created al Qaeda and ISIS?

Zia-ul-Haq, the Pakistani President, and his Inter Service Intelligence agency, the ISI did, but the money to do it came from Reagan and the Saudis. Reagan and his minions funded the ISI to create the Afghan insurgency against the Russians, but total operational control was vested in Pakistan and the ISI. Charlie Wilson, the Democratic Congressman (and eponymous hero of Charlie Wilson's War) had bought into a propaganda film produced by a glamorous and politically connected socialite who had become a fan of Zia and his insurgents. The film featured a heroic Mujaheddin leader but didn't mention his early career throwing acid into the faces of women in Kabul who went out without their faces covered and provided bipartisan support for giving the ISI everything it wanted.

With full operational control, the ISI had plenty of resources left for building itself into panoptican styled on the KGB, and for fomenting trouble among Indian Sikhs and in Kashmir. But the ISI still had a mission in Afghanistan after the Soviets withdrew - ensuring that Afghanistan was ruled by Islamists friendly to Pakistan or kept in turmoil.

The Taliban and al Qaeda were the result.

ISIS is a simpler story. After Bush Too's war in Iraq, his idiot proconsul Paul Bremer turned the Iraqi army out without jobs or pensions - but with weapons.

How We Got Into Afghanistan

To the extent that we remember at all, Americans have only a dim idea how we got first got involved in Afghanistan. Something about the Soviet invasion, followed by the CIA and "Charlie Wilson's War." Husain Haqqani tells some more of the story in "Magnificent Delusions."

After Army Chief Zia-ul-Hac overthrew the elected government of Pakistan and murdered the elected President, he faced rebellions in some provinces. When the British divied up the subcontinent, they had deliberately divided the Pashtun peoples, placing some of them in Pakistan and the rest in Afghanistan. This resulted in persistent demands for a united "Pashtunistan." Meanwhile, a somewhat leftist government had been elected in Afghanistan and adopted policies (land reform, rights for women) that offended large landowners and Islamic fundamentalists.

Zia responded by training, funding, and supplying Islamist insurgents, creating an Afghan civil war. This war probably played a key role in provoking or enabling the rather small Communist faction into overthrowing the elected Afghan government and taking power. At this point, Zia, pointing to the Communist threat, was able to enlist American President Jimmy Carter into small scale support for Zia-ul-Hac's Afghanistan war - thereby making the US the first great power to become deeply involved. Six months later, the Soviets invaded.

Because Pakistan, against US wishes, was developing a nuclear weapon, the US had stopped all military aid to Pakistan. The Soviet invasion changed all that.

The US policy that emerged immediately after Soviet troops moved into Afghanistan revolved around Pakistan. As Vance wrote in his memoir, Carter was willing to seek congressional approval to waive the legal prohibition on military aid to Pakistan. At the same time the United States would reaffirm its nuclear nonproliferation policy and press Pakistan to provide acceptable guarantees that it would not develop a nuclear weapon. But the first step was to reach agreement with Pakistan on the terms of an assistance package.

The relationship between the United States and Pakistan had flipped. The New York Times headline “Pakistan Is No Longer the Ardent Suitor, but the Prize to Be Courted” captured it exactly. 56 Zia handled the new situation with panache. He was eager to partner with the United States, but he made it seem like a difficult decision. He emphasized Pakistan’s “strategic position” and its being the “backdoor to the Gulf” and praised the United States as the champions of the free world. 57 But he also spoke of the vulnerability of Pakistan to Soviet and Indian pressures.

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (pp. 247-248). PublicAffairs. Kindle Edition.

In effect, Zia had mouse trapped the US and the Soviets into a confrontation that ultimately would be disastrous to both.

Zia was both a cunning and treacherous fellow, but his plans could not have succeeded without a large dollop of American stupidity.

Here is Reagan, somewhat later:

After meeting Zia, Reagan wrote in his diary for that Tuesday: “The weather turned out fine for the official greeting ceremony for Pres. Zia of Pakistan. We got along fine. He’s a good man (cavalry). Gave me his word they were not building an atomic or nuclear bomb. He’s dedicated to helping the Afghans & stopping the Soviets.”

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (p. 229). PublicAffairs. Kindle Edition.

Sunday, May 24, 2015

All Physics is Local

In Kerson Huang's book, The Fundamental Forces of Nature: The Story of Gauge Fields he notes that the principle of local gauge invariance "removes the last vestige of action at a distance from physics." The reason for this is that the job of keeping track of the field has been merged with spatial displacement via the replacement of the ordinary derivative in the Hamiltonian by a gauge covariant derivative.

The notion of gauge was introduced into physics by Hermann Weyl, the distinguished mathematician, in an attempt to unify electromagnetism and general relativity. It didn't actually work out in its original version, because, as Einstein pointed out, it implied unphysical effects. As often happens, with a little reinterpretation it was quickly recognized as a key feature of electromagnetism, and with the rise of the standard model and the idea of Yang-Mills fields, the key principle for all the fundamental forces of nature.

I find it mysterious but fascinating.

Class and Inequality

Hunter gatherers are strongly egalitarian. Sedentary agriculturalists tend to develop hierarchical class structures. The lowest classes tend to be profoundly repressed.

Why so? If we dismiss the usual idiotic ideas based on divine ordination or social Darwinism, what are we left with?

One cardinal fact about the sedentary lifestyle is that it permits much higher birth rates. The higher birth rates mean that societies produce a lot more people than they can feed. In effect, to prevent being torn apart by internecine struggles, societies develop what amounts to a designated dying class. Like the development of organized warfare, another agricultural innovation, having an oppressed class increases the death rate.

At least in large societies, two classes doesn't seem to be enough. Perhaps three or more are needed for stability. Because the upper classes are likely to out reproduce and out survive the lower classes, means for class demotion are also needed. That fear of class demotion, for example, forms a central theme in novels like "Pride and Prejudice" and "War and Peace."

The means to escape the Darwinian jaws of brutal class oppression and war were not really available until quite recently in history. Birth control, even mandatory birth control, seems a lot more humane to me that those alternatives.

Friday, May 22, 2015

Going to the Matrices

The expression "going to the mattresses" should be familiar to fans of The Godfather or of Nora Ephron's You've Got Mail. It's what Mafioso, or presumably, book store owners, do when they go to war.

In linear algebra and geometry, the sophisticated prefer to speak of the advantages of coordinate free representations, but, when the rubber meets the road, they often "shut the doors and compute with matrices," as one wag put it.*

I was reminded of that by my current interest in tensor networks, where the action is precisely in matrices (and their higher rank analogs.

* Actual quote, from Irving Kaplansky, speaking of himself and Paul Halmos:

We share a philosophy about linear algebra: we think basis-free, we write basis-free, but when the chips are down we close the office door and compute with matrices like fury.

And a different opinion from Dieudonne:

There is hardly any theory which is more elementary [than linear algebra], in spite of the fact that generations of professors and textbook writers have obscured its simplicity by preposterous calculations with matrices.

Both via Mathoverflow

Locality in Physics

The world looks simpler when we confine ourselves to local interactions. We affect the world mostly by local interactions. If we want to move something, we usually need to push on it. When Newton discovered his law of universal gravitation, with its action at a distance, that conception of locality was profoundly challenged. He didn't like it, but he could discover no satisfactory hypothesis to explain it. Electricity and magnetism turned out to present similar challenges.

The invention of the electromagnetic field by Faraday and Maxwell changed all that. Field strengths, and the forces they generated were now determined by the fields and charges in the local neighborhood, in effect pervading space with an ether that transmitted the forces. Einstein showed that the ether had to be Lorentz invariant and that gravity too could be localized, with the gravitational field now being determined by the matter and fields in the neighborhood.

One reason this is interesting today is the discovery of the fact that the quantum physics of certain many body systems is radically simplified if the Hamiltonians of those systems have the locality property. These ideas are embodied in so-called tensor networks. In particular the quantum entanglement entropy of such systems can be shown to be proportional to the area of the system boundary. Equally fascinating, effective geometry appears to appear naturally from such tensor networks.

For students of General Relativity and String Theory, this should loudly clang several bells with names like Bekenstein entropy, the Holographic Principle, Maldacena duality, quantum information and spacetime, and Wheeler's 'It from Bit'. These ideas are being actively pursued, and Jennifer Ouellette has a popular level article here in Quanta. A semi-technical article on the fundamental tool, the tensor network is:

Wednesday, May 20, 2015

Divorce, Pakistani Style

For various reasons, nearly all of them bad, the US clung to its alliance with the Pakistani generals despite repeated demonstrations that they were unreliable and frequently treacherous allies. This was much more dramatic during the Eisenhower and Nixon years than during the Kennedy administration, mostly because Nixon, like Dulles and Kissinger saw the world thru Manichean glasses. Relatively stable and progressive India, by pursuing socialist ideas and hewing to a neutralist line in the cold war became a "Soviet stooge" for them. Meanwhile, the repressive and incompetent but Sandhurst educated Pakistani generals spoke a language that they could appreciate, even when their double dealings were repeatedly exposed. In their conversations (as revealed by Nixon's tapes) Indira Gandhi was dismissed as a "bitch" and an "old witch".

Nixon did have one relatively good reason for hanging onto the Pakistani generals: Yahya Khan was his pipeline to the Chinese leadership and a key element in his plan to open relations with China.

Meanwhile Pakistan was falling apart. The Bengalis of East Pakistan, a badly treated majority in their own country, were sick of ill-treatment by the Pashtun and Punjabis of West Pakistan who dominated the military and government. After an election dominated by the Bengali party, Pakistan's generals plotted to hold on to power by military force.

The December 1970 election had brought Pakistan’s fissures to the fore. In response, West Pakistanis reacted with shades of ethnic superiority. Soon after the elections a general visiting Dhaka told his military colleagues: “Don’t worry. We will not allow these black bastards to rule over us,” a reference to the darker skin color of Bengalis compared to Pashtuns and Punjabis. 48 “The Punjab is finished, smashed,” an industrialist told the Times. “Our country has gone to the dogs,” he said, because “We will be ruled by Sindh and Bengal,” a reference to the fact that Mujib was Bengali whereas Bhutto was an ethnic Sindhi.

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (p. 150). PublicAffairs. Kindle Edition.

After feigning negotiations, Yahya Khan unleashed military repression.

US officials knew Ahsan and Yaqub [Pakistani officers who opposed the intervention] well, so Washington should have heard their views. But the United States chose to stand by Yahya. A new military commander, Lieutenant General Tikka Khan, arrived in Dhaka in March 1971 to enforce national unity with US weapons supplied ostensibly to save South Asia from communism. Pakistani soldiers then confined foreign journalists to their hotels before starting “Operation Searchlight,” a ferocious military action aimed at arresting and killing Awami League leaders. During this military operation at least ten thousand civilians were massacred within three days. There was a large Pakistani force already stationed in East Pakistan, but reinforcements and equipment were flown in from West Pakistan to bolster their strength.

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (p. 151). PublicAffairs. Kindle Edition.

US diplomats, the press, and much of Congress were outraged by Pakistan's atrocities, but Nixon and Kissinger were unwilling to risk their pipeline to China, even while they concluded that Yahya Khan was delusional and not very bright. Kissinger and Nixon may have brighter, but they were also delusional, attributing the slaughter in East Pakistan to Hindu-Muslim conflicts while in fact they were nearly completely irrelevant.

Nixon continued his delusional support of Yahya Khan even after India intervened on behalf of the Bengalis. The Pakistani army quickly collapsed and surrendered, but the generals continued their policy of attempting to deceive their own people.

The headline of Dawn, Pakistan’s major English newspaper, on the day of Pakistan’s surrender read, “Victory on All Fronts.”

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (p. 169). PublicAffairs. Kindle Edition.

Readers inclined to think of Kissinger and Nixon as both immoral and not too bright probably won't change their mind on the basis of Haqqani's book. The picture painted of Pakistan's military leadership is more like tragic-comically stupid.

Indian Puzzles

Geological Edition

When an unstoppable force like the Indian subcontinent crashes into an immovable object like the Eurasian plate, the consequences include the tallest mountains in the world and a cadence of earthquakes like the magnitude 7.8 one that struck Nepal last month and a major aftershock in the same region last week.

Many of the geological questions about the collision remain unanswered. How did the Indian subcontinent get so quickly to where it is today? How big was India originally? Even the simplest of questions — when did India meet Eurasia, the tectonic plate that Europe and Asia sit on? — is up for debate, with researchers offering answers that differ by some 30 million years.

From a New York Times article by Kenneth Chang.

It seems that there are many puzzles about the details of the collision, and several inconvenient facts of involving the when, where, and what of the collision. In particular, it's not why the subcontinent is moving so fast, whether there were two or more subduction zones involved, and what has moved under Asia so far.

Tuesday, May 19, 2015

Exploding Superstars

Exploding Superstars: Understanding Supernovae and Gamma Ray Bursts by Alain Mazure and Stephane Basa is a very well-written and interesting book, somewhat marred by flaws which I prefer to attribute to the evil that has come to dominate Springer. If you prefer to avoid the rant and get to the recommendation, skip the next paragraph.

The book is a translation from the French original, and, so far as I can tell, excellently done, but the title is a bit misleading. Although Supernovae and Gamma-Ray Bursts are prominently featured, the real subject is cosmology, as indicated the the original French title, which was something like "the Universe in all its glory". The text makes frequent mention of twenty or so color plates - these do not make an appearance in this English edition - a considerable loss. There are also many dozens of figures and diagrams many of which appear to have originally been done in color but have been reproduced by some idiotic process which destroys detail and contrast, sometimes making them all but unintelligible.

Now to some of the virtues: Clear and enthusiastic text with mostly non-mathematical descriptions of what the modern science of cosmology has learned. The numerous diagrams, despite the flaws detailed above, clarify and explain many key points. There is also a mathematical appendix, which very briefly summarizes many of the key physical points. Another innovation which impressed me was that instead of a bibliography it includes with a webliography, a list of web sites with relevant material keyed to the chapters.

The story that the book tells is that of the interlocking pieces of evidence that give rise to what is now called the "Concordance Model" of our cosmos. It's a story that with a beginning, some possible endings, and wealth of fascinating details. Regular readers of this blog probably know the principal underpinnings: the Hubble expansion, the Cosmological Microwave Background radiation, Einstein's general relativistic theory of gravity, the very large scale uniformity of the cosmos, the apparent flatness of the cosmos at the largest scales, and the multiple lines of evidence indicating that much of the energy and matter in the universe is "dark".

It's a scientific mystery story of the first order, and even though much of the plot has been revealed, many deep mysteries remain: what is the nature of dark matter and dark energy, what physics is responsible for the fact that we live in a matter rather than anti-matter universe, and what led to the Big Bang itself?

Monday, May 18, 2015

FOTD: Once More Into the Breach

The motto on the Hell's Angels home page is a quote from Henry V in Shakespeare's eponymous play. An excerpt from the famous Saint Crispin's Day speech before the Battle of Agincourt.

Saturday, May 16, 2015

Out of Work

Barbara Ehrenreich reviews Rise of the Robots and Shadow Work in the NYT Sunday Book Review. Excerpt:

In the late 20th century, while the blue-collar working class gave way to the forces of globalization and automation, the educated elite looked on with benign condescension. Too bad for those people whose jobs were mindless enough to be taken over by third world teenagers or, more humiliatingly, machines. The solution, pretty much agreed upon across the political spectrum, was education. Americans had to become intellectually nimble enough to keep ahead of the job-destroying trends unleashed by technology, both robotization and the telecommunication systems that make outsourcing possible. Anyone who wanted a spot in the middle class would have to possess a college degree — as well as flexibility, creativity and a continually upgraded skill set.

But, as Martin Ford documents in “Rise of the Robots,” the job-eating maw of technology now threatens even the nimblest and most expensively educated. Lawyers, radiologists and software designers, among others, have seen their work evaporate to India or China. Tasks that would seem to require a distinctively human capacity for nuance are increasingly assigned to algorithms, like the ones currently being introduced to grade essays on college exams. Particularly terrifying to me, computer programs can now write clear, publishable articles, and, as Ford reports, Wired magazine quotes an expert’s prediction that within about a decade 90 percent of news articles will be computer-­generated.

This is not new to many of us, but it is starting to get more public attention. The implications include the greatest shift of power to capital since the invention of slavery.


In my youth I was a big fan of space opera - rollicking tales of interstellar adventure. Of course that requires some unphysical stuff like faster than light drive, etc. I can handle that, but sometimes the details bug me.

The sliver of the Earth that had been decorating the bottom edge of the main view screen suddenly fell away from view as the ship pulled out of orbit and headed for Jupiter.

Nathan wasn’t sure if it was his gentle acceleration curve or the new inertial dampeners, but the sensation was almost unnoticeable.

In fact, it was even a bit disappointing, and he wondered how much the dampeners would help if he really had to punch it. Fifteen minutes later they were traveling at half the speed of light, and Nathan had discontinued his burn.

Brown, Ryk (2012-12-30). The Frontiers Saga: Episodes 1-3 (Kindle Locations 1518-1522). Ryk Brown. Kindle Edition.

I think a well trained pilot ought to be able to figure out that it *was* his inertial dampers. The gentlest possible acceleration curve (constant acceleration) requires that acceleration = velocity/time = 1.5 x 10^8 (m/s)/900 s or 1.7 x 10^5 m/s^2, or about 17,000 times the acceleration of gravity. Either the "inertial dampers" are working really well or the crew would be more than a bit squished.

Not counting relativistic effects, which would make it slightly worse.

Thursday, May 14, 2015

Religion, Society and Violence

One of the favorite pretexts for war and violence in the world is religious differences. Religion has long been a primary organizing principle of societies, so it's hardly surprising that competing groups often come to violence and minorities are a favorite target when things go awry. It seems that the United States has a Commission on International Religious Freedom. Of course it's an American Commission, appointed by American politicians, so its hardly a completely unbiased source. The members, with a few exceptions, have typically European Christian or Jewish names. They do seem to take their job seriously, however, and their reports present plenty of examples.

Offending nations are classified by Tier (Tier one is worst) and whether the Tier is merely recommended or sanctioned by State Department designation. One might not be surprised to find that Tier 1 is dominated by the officially Communist states (China, Vietnam, and North Korea) and numerous Islamic states. Many of these states are officially intolerant.

Tier 2 includes the major states of India, Indonesia, and Russia. A large proportion of the world's population lives in the 33 monitored countries. Cuba is the only American country to make the list, and the European nations are mostly ex-Communist. There are countries that might qualify that don't make the list, for example Israel. Perpetrators include Communist governments, Muslims, Hindus, Christians and Buddhists (at least) and the victims list includes most or all of the above but is far longer, though in many cases perpetrators and victims cannot be clearly sorted.

Communist persecution obviously has declined with the collapse of Communism, but Islamic and Hindu fundamentalists/nationalists (among others) have jumped into the breach.

The worst violation of religious freedom is religious war, but that, at present, seems largely concentrated between Islamic groups and almost everybody else, including each other.

A Problem Population

A Boston U prof is taking some heat for a tweet or two. In one, she called "white college age males" a "problem population." The statement is perhaps annoying, but it's also true - or at least one of Bohr's "great truths." College age males of whatever race are one of the most dynamic elements of society. They become entrepreneurs, soldiers, political activists and athletes. They also protest, get in trouble with the law, and commit a lot of acts of societal foolishness.

It was offensive of her to single out whites, but it was a natural reaction to the focus of some of the more racist media (say Fox) on the trouble young black men get into. Young men, and women too, need what one thinker called "the moral equivalent of war." If opportunity to engage in it isn't there, they will tend to find war and its other immoral equivalents attractive.

Friday, May 08, 2015

Not India

Muslims had ruled India, or major parts of it, for many centuries before Britain displaced them. Hindus had gained ground during the British occupation, but Muslims still had a large presence in the Army, the civil service, and as land owners. Independence brought the threat, or at least the imagined threat, that they would be a submerged presence in the overwhelmingly Hindu population under democratic rule. Pakistan was created as an answer to this perception.

That one idea, of being Not India, was a very fragile premise on which to build a nation. Pakistan inherited a big expensive chunk of the Indian Army, but not the resources to fund it. Because the army and the civil service were the institutions of the elite who founded Pakistan, ways had to be found to fund them. Pakistan's solution was to tap into the US treasury on the dubious premise of being a bulwark against Communism and keep its people distracted with fulminations against India.

To Eisenhower and his military people, the British educated Pakistani military leaders were more personally compatible than the neutralist and socialist Nehru. Despite well founded doubts about the value of Pakistan as an ally, they mostly kept the gravy train running for the Pakistani military. Meanwhile, these military rulers did essentially nothing to advance Pakistan's economic development, finding it easier to fan religious fanaticism.

Kennedy proved a more resistant President. When India went to war with China, the US rushed military aid to India, outraging Pakistan, which saw the war as a chance to pursue its long time objectives in Kashmir. Pakistan's leaders stirred up public sentiment against the US while protesting to the US that they faced a popular revolt if the US would not be more cooperative. It was a double game which had appeared before and would again.

Wednesday, May 06, 2015

Military Takeover of Texas

It's about time.

Reconstruction ho!

EM Drive

Lumo has a long, sometimes entertaining, and frequently informative rant on EM Drive today. He thinks it and the publicity it is getting is nuts, and I'm pretty sure he right. I guess nearly every physicist is going to stick with Newton on this point.

Of course he adopts his usual dogmatic style, dismissing, or rather ignoring the possibility that some genuinely new physics might be involved. While I am virtually certain that he is right, I don't think that that is the right attitude to adopt toward claims like reactionless drives, cold fusion, ESP and so on. One should probably ignore such things, but if you choose not to, I think that the right attitude to adopt is Einstein's, namely that those things can only happen if some genuinely new physics is involved, and think about what that might imply. Usually, it implies a bunch of things that violate well established laws of physics and a lot of nonsense.

In particular (as Lumo and others have noted) it implies either that the whole of mechanics is bogus or that slightly odd configurations of electromagnetic fields can couple rather strongly to some previously unknown fluid. If you believe that (and I sure as heck don't), you ought to find some more fundamental method of investigation than building big microwave cans.

Holy Wars

Is it just coincidence that the world's biggest religions are also the ones famous for aggressive holy wars? The big religions of the East don't seem to have this character. Most religions, including Christianity and Islam make peace a virtue, but in their case that virtue is often trumped by their aggressive and frequently violent proselytization. Organized religion appears to have arisen with agriculture, and many such religions developed war gods, often tribal in nature. Such appears to have been the case with the Hebrew war god.

That god had a couple of notable characteristics, in that he had a very jealous character, and tolerated no other gods, and secondly, at some point he claimed universal dominion, becoming not just the war god of one tribe, but The God, not just of the Hebrews, but everybody. The aggressive proselytizing is mostly associated with Christianity and Islam, but had already begun in pre-Christian times.

I find it interesting that one of the most prominent modern, "humanist", religions, Marxism-Leninism, has the same intolerant, dogmatic and universalist character, only bases its universalist claims not on a personal god but on supposed laws of history. It too had considerable crusading success before it's internal inconsistencies brought it crumbling down.

There apparently is a universal human instinct to punish deviant behavior, and this instinct is crucial to the understanding of cooperation. Extending this instinct to punishing deviant thought is one of the most obnoxious qualities of the three religions mentioned, but, quite unfortunately, may also be essential to their successful spread.

Tuesday, May 05, 2015

South Asian Delusions

Truman had pursued a rather hands-off policy towards the new state of Pakistan, but that changed under Eisenhower. Secretary of State Dulles was preoccupied with building a ring of containment against Communism, and India's determination to stay out of big power alliances annoyed and frustrated him. Vice President Nixon was also firmly on board. They imagined that arming Pakistan would induce it to provide the US with bases and make it a bulwark against Communism.

Meanwhile, the Russians were deeply uninterested in Pakistan and Pakistani leaders cared mainly about protecting their elite status and controlling their diverse population by vague Islamist rhetoric and fulminating against India.

Some in the US had a clearer view:

Hans J. Morgenthau, the well-regarded scholar of international relations, raised similar doubts. “Pakistan is not a nation and hardly a state,” wrote Morgenthau in an article in the New Republic titled “Military Illusions.” “It has no justification in history, ethnic origin, language, civilization, or the consciousness of those who make up its population. They have no interest in common, save one: fear of Hindu domination. It is to that fear, and to nothing else, that Pakistan owes its existence, and thus far its survival, as an independent state.” He also derided the geographic and political distance between East and West Pakistan: “It is as if after the Civil War Louisiana and Maryland had decided to form a state of their own with the capital in Baton Rouge. In fact, it is worse than that.”

Haqqani, Husain (2013-11-05). Magnificent Delusions: Pakistan, the United States, and an Epic History of Misunderstanding (p. 79). PublicAffairs. Kindle Edition.

Those running the show, led by Dulles, were less clear eyed. He was ignorant enough to say the US needed Pakistan's famous Gurkha warriors (they are actually Hindus from Nepal - neither Muslim nor Pakistani).

Haqqani's book, like the book I just read on the origins of World War I by Macmillan, is further evidence of the enormous role of ignorance, self-delusion, and folly in international affairs.

Sunday, May 03, 2015

Official Languages

English is an official language in 35 countries.

The UK, the US and Australia are not among them.

Official languages are more important in countries where there is either great linguistic diversity or two or more major languages competing. Of the 7100 (or so) living languages about half are expected to die out by the end of the century. Chinese, Hindi-Urdu, English, Arabic, and Spanish have the largest numbers of native speakers, with Chinese alone having more that the third, fourth, and fifth languages combined.

A Little Knowledge/Dangerous Things

I was at a performance of William Missouri Burroughs' play Mad Gravity last night. It turns out the play involves a bit of audience participation, so at one point a character asks the audience if anyone knows the difference between an asteroid and a comet. My date pointed to me, so I offered that asteroids were rocky denizens of the inner Solar System while comets were icy wanderers of its distant outskirts.

It seems that the plot involved a close approach and possible impact by a comet.

I didn't get around to mentioning it, but overall comets are a heck of a lot more menacing than asteroids. Orbiting mostly in our near neighborhood, asteroids are pretty familiar, and the big ones on nearby trajectories are pretty well cataloged. If a really big one (major extinction class event) has our number, modern astronomy should see it coming for a few hundred years before impact, probably giving us enough time to persuade even the dumbest Republican climate denialist that we ought to do something about it. Also, asteroid orbits are mostly fairly similar to ours, so impact velocities would be "only" a few tens of thousands of kilometers per hour.

Comets, though, are invisible till they get pretty darn close, and falling through that big potential well of hundreds of astronomical units are moving very fast. Because they are spewing gas, dust and rock by the time they get this close to the Sun, even a near miss might be pretty calamitous. Warning times in weeks or less would imply that the most effective action we could take would be to bend over, place our heads between our legs, and kiss our asses goodbye.

Of course in 50 years, we might have other options.

Deus ex Machina

Via Brad DeLong, Zynep Tufekci in the NYT Sunday Review:

CHAPEL HILL, N.C. — THE machine hums along, quietly scanning the slides, generating Pap smear diagnostics, just the way a college-educated, well-compensated lab technician might.

A robot with emotion-detection software interviews visitors to the United States at the border. In field tests, this eerily named “embodied avatar kiosk” does much better than humans in catching those with invalid documentation. Emotional-processing software has gotten so good that ad companies are looking into “mood-targeted” advertising, and the government of Dubai wants to use it to scan all its closed-circuit TV feeds.

Yes, the machines are getting smarter, and they’re coming for more and more jobs.

Not just low-wage jobs, either.

Today, machines can process regular spoken language and not only recognize human faces, but also read their expressions. They can classify personality types, and have started being able to carry out conversations with appropriate emotional tenor.

Machines are getting better than humans at figuring out who to hire, who’s in a mood to pay a little more for that sweater, and who needs a coupon to nudge them toward a sale. In applications around the world, software is being used to predict whether people are lying, how they feel and whom they’ll vote for.


But computers do not just replace humans in the workplace. They shift the balance of power even more in favor of employers. Our normal response to technological innovation that threatens jobs is to encourage workers to acquire more skills, or to trust that the nuances of the human mind or human attention will always be superior in crucial ways. But when machines of this capacity enter the equation, employers have even more leverage, and our standard response is not sufficient for the looming crisis.

The original industrial revolution eventually made English workers much richer - after prolonged social struggles and unionization - it also turned hundreds or even thousands of Indian villages which had specialized in weaving into boneyards as the inhabitants starved.

The victims of the current, probably much more profound revolution are unlikely to be confined to far away continents. We are looking, I think, at a profound challenge to the way our whole societies are organized.

Original Alchemy

Primordial nucleosynthesis is one of the key pillars of what's called the Concordance Model of cosmology. It's importance comes from the fact that it predicts specific numerical details of elemental abundance in the modern universe. Only a few elements were synthesized in the early universe: helium plus very small amounts of deuterium, lithium, and beryllium. The fact that such nuclear reactions could take place only when the universe was cool enough for stable nuclei to exist and hot and dense enough for nuclear reactions to take place puts strict limits on the time scale of such reactions: from about 10 seconds after the big bang to about 20 minutes after.

Because the nuclear reactions involved are well understood from laboratory experiments, the observed abundances put tight constraints on the matter density of the universe at that time. In particular, they imply that only about 24 % of the matter density of the universe was in baryonic (proton + neutron) form. It would be a highly improbably coincidence that rotation curves of galaxies and galaxy clusters imply the same proportion of baryons to dark matter. The ratio of neutrons to protons can be calculated at neutrino decoupling (freezeout) from the Boltzman factor exp(- deltaM/kT), where deltaM is the mass difference between neutron and proton and T is the temperature of 1 Mev (roughly 10 billion kelvins), implying about 1 neutron per proton, nearly all of which are scarfed up into Helium 4.

Lots of details here:

Saturday, May 02, 2015

Tyranny of Time

I seem to have reached that point in my life when I can afford to buy more books than I have time to read.

Strictly speaking, I have always bought more books than I had time to read. Until recently, though, I couldn't actually afford them. Mostly my problem is that I buy hard* books.

* hard for me, that is.

Friday, May 01, 2015

Reactionless Drives

It seems that NASA and some companies are spending time and money on so-called reactionless electromagnetic drives. See also:

I would guess that well over 99% of physicists consider this bogus, no matter how often these things appear to produce a few micro Newtons of force, because they appear to violate conservation of momentum. The proponents nowadays claim some weird quantum mechanical vacuum effects are responsible.

Einstein once told the story of a conversation he supposedly had with another physicist who said: "I'm inclined to believe in ESP." Einstein reported that the conversation continued with him saying that: "This has more to do with physics than psychology" and his interlocutor replying "yes."

EM drives, if such things exist (and I very much doubt that they do, except in the case of Hogwarts brooms), similarly have more to do with physics than engineering. If you posit some kind of momentum violating funky quantum vacuum effect, you need to investigate it with methods of fundamental physics, not by building giant microwave pseudo engines.

Punishing Defectors

Humans are much better at cooperation than simple evolutionary models explain. Some, like Christopher Boehm, have suggested that cooperative punishment of defectors - rule breakers, liars, psychopaths, those who don't play together well, etc - is the key explanatory principle. Ernst Fehr and Simon Gachter, writing in Nature, claim to have experimental results demonstrating this. Their abstract:

Human cooperation is an evolutionary puzzle. Unlike other creatures, people frequently cooperate with genetically unrelated strangers, often in large groups, with people they will never meet again, and when reputation gains are small or absent. These patterns of cooperation cannot be explained by the nepotistic motives associated with the evolutionary theory of kin selection and the selfish motives associated with signalling theory or the theory of reciprocal altruism. Here we show experimentally that the altruistic punishment of defectors is a key motive for the explanation of cooperation. Altruistic punishment means that individuals punish, although the punishment is costly for them and yields no material gain. We show that cooperation flourishes if altruistic punishment is possible, and breaks down if it is ruled out. The evidence indicates that negative emotions towards defectors are the proximate mechanism behind altruistic punishment. These results suggest that future study of the evolution of human cooperation should include a strong focus on explaining altruistic punishment.

It's worth noting that this apparently fundamental human instinct, vital as it is to society, is put to all sorts of uses that are now considered inappropriate, or at least non PC: Xenophobia, racial discrimination, harassment and worse of heretics, picking on non-conformists, homophobia, etc., etc. At the least it explains why those behaviors are so hard to root out. At worst, yet more evidence that the human race is irretrievably flawed.

Unfortunately, the details are behind an evil Nature paywall, so I have no way to judge their experiment's methodology or validity.

Nevermind: An ungated copy: