Electron appears spherical, squashing hopes for new physics theories

Clara Moskowitz in Nature:

ElectronScientists are unanimous that their current theory of physics is incomplete. Yet every effort to expose a deeper theory has so far disappointed. Now the most sensitive test yet of the shape of an electron — a property that could expose underlying 'new physics' — has failed to find hints of anything novel. The finding rules out a number of favoured ideas for extending physics, including some versions of a popular idea called supersymmetry. The result came from a search for the so-called electric dipole moment in the electron. A familiar example of a dipole is a bar magnet, which is shaped like a dumbbell with a north and a south pole. Electrons are traditionally thought of as spherical, but if they had dipole moments, they would be slightly squashed. “It’s a question of: Does the electron look the same no matter which way you look at it?” explains physicist Jony Hudson of Imperial College London. “The dipole moment is physicists’ technical way to describe if it’s symmetric or not.”

The Standard Model of particle physics, which describes all the known particles in the Universe, predicts a practically zero electric dipole moment for the electron. Yet theories that include additional, yet-to-be-detected particles predict a much larger dipole moment. Physicists have been searching for this dipole moment for 50 years. Now a group called the ACME collaboration, led by David DeMille of Yale University and John Doyle and Gerald Gabrielse of Harvard University, has performed a test 10 times more sensitive than previous experiments, and still found no signs of an electric dipole moment in the electron. The electron appears to be spherical to within 0.00000000000000000000000000001 centimeter, according to ACME’s results, which were posted on the preprint site arXiv. “It’s a surprise,” says Ed Hinds, also of Imperial College London, who worked with Hudson on the previous best limit, set in 2011. “Why on Earth is it still zero?”

More here.

Friday Poem

Dalai Lama

The Dalai Lama continues to laugh
addressing
a large audience.

The interpreter is super-serious
has no time for laughter
The English was like a net
the Tibetan words butterflies,
flew from the flower-petal lips of the Dalai Lama
sometimes to sit on the ears of the Tibetan kids
sometimes on the gold-flecked robes,
maybe the wedding dresses
of the Tibetan women
taken out only on special occasions
but worn away at the hems
this bit of sparkle left
like the trace of light in aged eyes.

The Dalai Lama was expounding
the Four Noble Truths of Buddhism
He raised his arm and
like three little dots of ‘therefore’
there were the marks of childhood vaccination
peeping through his ochre robe.
They whispered:
Aha, someone is talking about such high principles
but is from this very world
this very epoch
and he’s just a man.

Right in front of me, rapt, a grandfather
on his shoulder a chubby little boy and his gurgling bottle
wiping his running nose
on grandpa’s sweater —
He must have been like that —
the Dalai Lama
What do we know of Tibet —
Rahul Sanknityayan or Rinpoches
monasteries and chow mein
cheap sweaters and sandals, China,
snow, lost eyes, round faces and faithful Lhasa Apso pups.

How do those noble truths
connect with
such random bits,
the ignoble truths of life?

Does truth too have hierarchies?
A caste system? —
Brahmin truths at the top
and then the Shudra truths at the bottom?

Hunger and
thirst
heat and cold
attachment and cruelties
Love and hate —
are these truths really lower?

Dalai Lama, you tell me, please:
if the truth is like these mountain ranges —
high and low.
I prefer living in the deep cave of a small truth
occasionally coming to you
to learn the nobler truths of life.

by Anamika
from Khurduri Hatheliyan
publisher: Radhakrishna Prakashan, Delhi, 2005
translation: 2006, Arlene Zide and Anamika

Thursday, November 14, 2013

Iran’s Plutonium Game

Jeremy Bernstein in the New York Review of Books:

ScreenHunter_396 Nov. 14 16.42There have been conflicting reports about why the much-watched negotiations in Geneva failed to produce an interim agreement about Iran’s nuclear program. On Monday, senior US officials said that the Iranian delegation was not ready to sign on to a draft agreement, which called for a six-month freeze in Iran’s uranium enrichment activity to allow time to produce a comprehensive accord. But over the weekend, French officials gave another reason: the French government is concerned about the continuing construction of a heavy-water nuclear reactor at Arak.

In fact, to anyone who has been following the Iranian nuclear program, it was almost a forgone conclusion that negotiations with Iran would hit a road block when it came to the so-called IR-40 reactor located in Arak. The “40” here refers to the projected power output of forty megawatts of thermal power. To convert this into electric power involves a cumbersome process. The thermal power, which is generated in the form of energetic fission fragments in the reactor, must be converted into steam to run inefficient steam turbines. Thus much of the original reactor generated energy is dissipated; something like only a third of this power could be converted into electricity. And since one large building alone can use several megawatts of power, it is hard to imagine generating much electricity from a forty-megawatt reactor. Whatever the IR-40’s intended use, it is not to produce electric power. A reactor designed for that purpose—such as the one at Bushehr—produces billions of watts.

Moreover, there is nothing about the reactor’s declared purpose that would require it to be a heavy water reactor. According to the Iranian government, the IR-40 reactor is supposed to make medical isotopes. But a light water reactor would have served the stated purpose just as well—and generate the same amount of power.

What makes the Arak reactor suspicious, then, is the design. To understand this we need to understand how a heavy water reactor works.

More here.

Upper-caste India’s debt to Ambedkar

Namit Arora in Caravan:

ScreenHunter_395 Nov. 14 16.30Turn in any direction you like, caste is the monster that crosses your path,” wrote Bhimrao Ramji Ambedkar, India’s foremost crusader for dignity and civil rights. That monster has always haunted Ambedkar’s legacy, polarising it along caste lines. On the one hand is his godlike presence in Dalit communities, who, out of affection and admiration, have built countless statues of him, usually dressed in a Western suit and tie, with a fat book under his arm, and in whose folk songs, poems, and calendar art he has long held pride of place. For generations, his bold, secular, and emancipatory ideas inspired many low-caste activists and writers, many of whom recall their lives in “before-and-after Ambedkar” phases. When Omprakash Valmiki, the author of the memoir Joothan: A Dalit’s Life, first read about Ambedkar’s life and work, he “spent many days and nights in great turmoil.” He grew more restless; his “stone-like silence” began to melt, and “an anti-establishment consciousness became strong” in him. Ambedkar gave voice to his muteness, Valmiki wrote, and raised his moral outrage and self-confidence.

On the other hand, there remains a longstanding apathy for Ambedkar among caste Hindus. What respect he does get from India’s elites is usually limited to his role as the architect of the constitution—important, but arguably among the least revolutionary aspects of his legacy. The social scientist and educationist Narendra Jadhav, interviewed in the Times of India earlier this year, described Ambedkar as the “social conscience of modern India”, and lamented that he has been reduced to being “just a leader of Dalits and a legal luminary.” Indeed, even thoughtful, liberal elite Indians are commonly ignorant about Ambedkar’s life and social impact, both in his lifetime and in the decades since—as the scholar Sharmila Rege noted in Against the Madness of Manu: BR Ambedkar’s writings on Brahmanical Patriarchy, not only lay readers, but Indian post-graduates and academics in the social sciences, humanities, and women’s studies are also unlikely to have read him. What explains this severe disjunction in how Ambedkar is received in India?

More here.

The Math Trick Behind MP3s, JPEGs, and Homer Simpson’s Face

Aatish Bhatia in Nautilus:

1620_806beafe154032a5b818e97b4420ad98Nine years ago, I was sitting in a college math physics course and my professor spelt out an idea that kind of blew my mind. I think it isn’t a stretch to say that this is one of the most widely applicable mathematical discoveries, with applications ranging from optics to quantum physics, radio astronomy, MP3 and JPEG compression, X-ray crystallography, voice recognition, and PET or MRI scans. This mathematical tool—named the Fourier transform, after 18th-century French physicist and mathematician Joseph Fourier—was even used by James Watson and Francis Crick to decode the double helix structure of DNA from the X-ray patterns produced by Rosalind Franklin. (Crick was an expert in Fourier transforms, and joked about writing a paper called, “Fourier Transforms for birdwatchers,” to explain the math to Watson, an avid birder.)

You probably use a descendant of Fourier’s idea every day, whether you’re playing an MP3, viewing an image on the web, asking Siri a question, or tuning in to a radio station. (Fourier, by the way, was no slacker. In addition to his work in theoretical physics and math, he was also the first to discover the greenhouse effect [pdf].)

So what was Fourier’s discovery, and why is it useful?

More here.

How did ancient Greek music sound?

Armand D'Angour at the BBC:

_70644615_010083090-1Suppose that 2,500 years from now all that survived of the Beatles songs were a few of the lyrics, and all that remained of Mozart and Verdi's operas were the words and not the music.

Imagine if we could then reconstruct the music, rediscover the instruments that played them, and hear the words once again in their proper setting, how exciting that would be.

This is about to happen with the classic texts of ancient Greece.

It is often forgotten that the writings at the root of Western literature – the epics of Homer, the love-poems of Sappho, the tragedies of Sophocles and Euripides – were all, originally, music.

Dating from around 750 to 400 BC, they were composed to be sung in whole or part to the accompaniment of the lyre, reed-pipes, and percussion instruments.

More here.

on a new translation of Herodotus

Fec64d26-4c72-11e3-_384297hEdith Hall at the Times Literary Supplement:

The Hellenist John Herington once called Herodotus a literary “centaur”, because from the front he looks like a rational intellectual, but his rear parts belong to a primitive creature of the wild. Herodotus’ pioneering prose treatise sought to explain the nature of the world he inhabited, in the mid-fifth century BC, from the events that had taken place across the Mediterranean and Black Sea regions during the reigns of four Persian kings – Cyrus, Cambyses, Darius and Xerxes. These culminated in the victory of Greece over Persia in 480–479 BC. Herodotus, the “father of history”, often uses rational explanations, backed up by evidence. But he also includes many traditional stories and legends, with patently fantastic elements, derived from poems, fables and oral tradition. Herodotus therefore needs a versatile translator who appreciates his hybridity. Enter Tom Holland, a distinguished and highly readable author of both historical non-fiction dealing with ancient empires (Persian Fire, Rubicon,Millennium, The Shadow of the Sword) and popular fantasy novels. He knows more than most of us about how to evoke both real and imagined scenarios with economy, elegance and gusto. Although there is no shortage of rival translations on the market, the Herodotus of Holland has therefore been eagerly awaited.

more here.

Augustan Satire Reconsidered

Tale-stagesBrooke Allen at The Hudson Review:

And what riches they are! How tempting are obscure titles like the Earl of Rochester’sSeigneur Dildoe! Or David Garrick’s Shakespearean parody Ragandjaw, in spite of the fact that according to Marshall it “provides little more than sophomoric humor and coarse entertainment.” It makes us wonder which of our own topical satires will stand the test of a couple of hundred years. Perhaps as few as comprise the standard Restoration and Augustan canon; for of all the literary modes in existence, satire is the most “purposive,” to use academic jargon—the most dependent on events of the moment. South Park, screamingly funny now, will probably be incomprehensible to viewers a century hence, while some of Stephen Colbert’s apparently topical rants might prove to be for all time: his classic “Truthiness” episode is as universally applicable as some of the masterpieces of his spiritual forebear, Jonathan Swift. Dr. Strangelove, which would seem to be deeply inscribed in the context of Cold War paranoia, still speaks to us as strongly as ever and will probably do so for many decades to come. Scholars and common readers of the future will determine the late twentieth- and early twenty-first-century canon, but it is probably safe to say that, as has been the case with the Augustans, the works that will last are those that deal with human nature itself rather than mere current events.

more here.

the Least Known Masterpiece of European Literature

Leopardi,_Giacomo_(1798-1837)_-_ritr._A_Ferrazzi,_Recanati,_casa_LeopardiAdam Kirsch at The New Republic:

Leopardi found his way to an idea that troubled all the major Romantic poets and thinkers. What sets him apart is that, while most Romantics saw the disenchantment and alienation of the modern world as a problem to be solved (M. H. Abrams’s Natural Supernaturalism is the classic account of the attempted solutions), Leopardi saw it as a fate to be endured. Scientific reason, to Leopardi, was a curse not because it falsified the world but precisely because it showed the world truly: a place devoid of purpose, meaning, and providence. “Reason … recognizes how unimportant all things are,” he remarks. Where Wordsworth taught his readers to cultivate joy and trust in nature, Leopardi told his, in “Broom,” that nature, “the truly guilty,” is man’s wicked stepmother, responsible for all our unhappiness.

If reason tells us an unbearable truth, then our only salvation is ignorance: “There is no other remedy for the ills of modern philosophy than forgetting.” Yet Leopardi does not really believe that forgetting is possible. Ignorance, like paradise, cannot be regained once it is lost, and the man who knows the truth has no recourse but to envy those who do not know—such as children, whose instincts remain strong because they live in a world full of nourishing illusions. “Children find everything in nothing, men find nothing in everything,” as he puts it at one of the rare moments when the flow of his thoughts condenses into aphorism.

more here.

QI facts

John Lloyd, John Mitchinson and James Harkin in The Telegraph:

Pencils_2727185cWhen we came to write our first volume of facts – 1,227 Quite Interesting Facts to Blow Your Socks Off – last year, we set ourselves the goal of producing 1,000 nuggets of information that seemed to us unforgettable. We pooled 10 years of extraordinary comparisons (there are 1,000 times as many bacteria in your gut as there are stars in the Milky Way); astonishing statistics (a single male human produces enough sperm in two weeks to impregnate every fertile woman on the planet); unexpected truths (the Bible is the most shoplifted book in the United States) and memorable absurdities (Richard Gere’s middle name is Tiffany), and then counted up what we had. It turned out we had a file of 1,227 facts, which seemed both more interesting and more appropriate than the 1,000 we’d originally targeted. In the course of editing and arranging that material we discovered something surprising: the facts seemed to have a mind of their own. Far from being inert bits of trivia, they behaved much more like molecules, bristling with energy and a desire to form strong attractions with other facts to make longer and more meaningful sentences. All we had to do was keep trying the best combinations.

…Once you are in the Fact Zone, everywhere you look, astonishing new facts seem to demand inclusion. And, to adapt a line of Groucho Marx: if you don’t like them, we’ve got others….

All the mountains on Saturn’s moon Titan are named after peaks in The Lord of the Rings.

Women look their oldest at 3.30pm on Wednesdays.

Agatha Christie was a keen surfer.

Speed dating was the brainchild of a rabbi.

There is enough carbon in your body to make 9,000 pencils.

More here.

Something Very Big Is Coming

Stephen Wolfram in his Blog:

Something-big-comingComputational knowledge. Symbolic programming. Algorithm automation. Dynamic interactivity. Natural language. Computable documents. The cloud. Connected devices. Symbolic ontology. Algorithm discovery. These are all things we’ve been energetically working on—mostly for years—in the context of Wolfram|Alpha, Mathematica, CDF and so on.

But recently something amazing has happened. We’ve figured out how to take all these threads, and all the technology we’ve built, to create something at a whole different level. The power of what is emerging continues to surprise me. But already I think it’s clear that it’s going to be profoundly important in the technological world, and beyond. At some level it’s a vast unified web of technology that builds on what we’ve created over the past quarter century. At some level it’s an intellectual structure that actualizes a new computational view of the world. And at some level it’s a practical system and framework that’s going to be a fount of incredibly useful new services and products. I have to admit I didn’t entirely see it coming. For years I have gradually understood more and more about what the paradigms we’ve created make possible. But what snuck up on me is a breathtaking new level of unification—that lets one begin to see that all the things we’ve achieved in the past 25+ years are just steps on a path to something much bigger and more important.

More here.

Wednesday, November 13, 2013

Christian, Not Conservative

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Robert Long on the appeal of Marilynne Robinson’s literary—and liberal—Calvinism, in The American Conservative:

Gilead not only won the Pulitzer but sold enough copies to become “one of the most unconventional conventionally popular novels of recent times”—as James Woodput it in the New Yorker—thanks to passages like this one, near the end of the book(and of Ames’s life):

Wherever you turn your eyes the world can shine like transfiguration. You don’t have to bring a thing to it except a little willingness to see. Only, who could have the courage to see it? … Theologians talk about a prevenient grace that precedes grace itself and allows us to accept it. I think there must also be a prevenient courage that allows us to be brave—that is, to acknowledge that there is more beauty than our eyes can bear, that precious things have been put into our hands and to do nothing to honor them is to do great harm.

Chief among the “precious things” Robinson honors is America’s religious heritage. She is in a sense a culture warrior, striving against what her essays call our “impulse … to disparage, to cheapen and to deface, and to falsify, which has made a valuable inheritance worthless.”

For this reason her nonfiction, like her novels, attracts the attention of thoughtful conservatives. In a Weekly Standard review of last year’s essay collection When I Was a Child I Read Books, Houston Baptist University professor Micah Mattix praises Robinson’s contrarian projects: defending America’s Puritans (and their forefather, John Calvin) from their caricature as dour fundamentalists, championing the Old Testament as wise and humane, and critiquing the reductionist materialism of the New Atheists. To all this, Robinson brings a “penchant for the ignored fact and the counterintuitive argument.”

The thread that unites these concerns is a tradition neglected today by left and right: liberal Christianity.

More here.

Fluid Dynamics Explains Some Traffic Jams

Isns

Joel Shurkin in Physics Buzz (Image credit: Alexandre Dulaunoy via flick):

The problem of random traffic jams on most roads, said Berthold Horn, an electrical engineer and computer scientist at MIT, is sometimes described as an issue of fluid dynamics. Other scientists point to chaos theory and fractals to explain the phenomenon.

An analogy Horn uses is dilatant fluid, a fluid that gets thicker as stress is applied. For example, if you put enough corn starch into a swimming pool, you could walk across it on the surface. The content of the pool would remain a liquid but it would thicken under the pressure of your step. YouTube is full of examples, Horn said.

The water in the pool is called a Newtonian liquid because no matter what you do with it — shake or stir — it remains a liquid. Once you add the corn starch, it becomes a non-Newtonian liquid and solidifies under pressure.

Ketchup, incidentally, is the reverse. It is mostly a solid in the bottle until you shake or squeeze it, then it becomes a liquid. The non-Newtonian properties of ketchup are the reason it is so hard to get it out of a glass bottle.

Now, think of the stream of traffic as a liquid. When you reach a certain number of cars in a certain area simultaneously, Horn said, the traffic “thickens,” and everyone slows down because everyone is reacting to the car in front of them.

Horn, thinks he has found the solution in luxury cars–adaptive cruise control, which uses radar to monitor the car ahead of you. If that car slows down, so does yours, in direct proportion to what the other car is doing.

What Horn wants to do is watch the rear as well.

He calls it bilateral control: To keep traffic moving, you also have to look behind you.

More here.

Reflections on Violence, Law, and Humanitarianism

Asad

Talal Asad in Critical Inquiry:

Steven Pinker has recently argued that the modern world has become far less violent (“more civilized”) than at any time in history. True, there may have been massive destructions of human beings in the twentieth century butproportionately these were less significant than the violence of premodern times when human populations were less dense on the globe. He explains this decline in human violence in terms of the growth in refined feelings attributable to the Enlightenment’s commitment to reason and to the gradual development of bodily and emotional self-control—to what Norbert Elias called “the civilizing process”—as well as to the emergence of the state. Thus the modern state is seen not only as the crowning achievement of liberal democracy but also as the basis of a wealthy civilization founded on capitalism in which general concern for human well-being can flourish. This is consistent with a widespread belief that, since the end of the eighteenth century, peoples in Euro-America have become increasingly free and humane because freedom and humanity naturally reinforce each other.

But the conditions of benevolence are more complicated than this story would suggest. Take the modern US prison system, for instance. What are we to make of the fact that US correctional system, with all its cruelty, contains a far higher proportion of prisoners to the total US population than it ever did before? Pinker thinks the very high rate of African-Americans in prison is evidence of a “decivilizing” process (the felons come largely from dysfunctional families) and sees the prison system as the necessary incarceration of actual and potential perpetrators of violence. The legal historian James Whitman has, however, a provocatively different view: It is precisely the political culture of liberal democracy, he declares, by which this modern statist form of violence is to be explained. Democratic politics enters more directly into the shaping of criminal legislation in America than it does in Europe largely because politicians who seek election want to be seen as being “tough on crime.” By contrast, democratic politics don’t permeate the European criminal justice systems, both because framing the law is largely a bureaucratic expertise and because judges and prosecutors are not publicly elected in European countries as they are in the United States. Hence the paradox: the more pervasive the principle and practice of political freedom in liberal democratic society, the greater the probability of punitive vindictiveness.

In sum: it may not be the benevolent values of “our moral culture” that matter but the contrary work done by legal disciplines and political structures.

More here.

philly in the 50s

1383824063874Dan Burt at Granta:

Prostitution, gambling, fencing, contract murder, loan-sharking, political corruption and crime of every sort were the daily trade in Philadelphia’s Tenderloin, the oldest part of town. The Kevitch family ruled this stew for half a century, from Prohibition to the rise of Atlantic City. My mother was a Kevitch.

Not all Jewish boys become doctors, lawyers, violinists and Nobelists: some sons of immigrants from the Pale became criminals, often as part of or in cahoots with Italian crime families. A recent history calls them ‘tough Jews’: men like Meyer Lansky and Bugsy Siegel, who organized and ran Murder Incorporated for Lucky Luciano in the ‘twenties and ‘thirties, and Arnold Rothstein, better known as Meyer Wolfsheim in The Great Gatsby, who fixed the 1919 baseball World Series. The Kevitch family were tough Jews.

Their headquarters during the day was Milt’s Bar and Grill at Ninth and Race, the heart of the Tenderloin, two miles north of Fourth and Daly. At night one or more male clan members supervised the family’s ‘after hours Club’ a few blocks away. We called Milt’s Bar the Taproom and the after hours club The Club.

more here.

losing faith in the internet god

1383858953rsz_9172738462_f2ff393ca2_cGeoff Shullenberger at Dissent:

According to two recent books, many people today believe in the Internet the way that the denizens of the Age of Faith believed in God, or that many on the left once believed in Marxism: as the exclusive source of universal personal and political salvation and the basic organizing principle of history. Varieties of this twenty-first century faith can be found in the most disparate places. While the geek elite of Silicon Valley are its natural constituency, other converts include young Egyptians who took part in the 2011 uprising, free-market libertarians, members of the Obama administration, “hacktivists,” open government activists, and a growing tribe of calorie-counting “self-trackers.”

Evgeny Morozov and Jaron Lanier are themselves lapsed true believers in the Internet gospel, though Morozov tells us he was only “one of those people . . . very briefly,” whereas Silicon Valley insider Lanier was a seminal figure in developing some of the technologies and ideologies he now criticizes. Both assert that the widespread and quasi-messianic enthusiasm for the Internet underwrites a technocratic agenda inimical to the survival of democracy.

more here.

thinking about woody allen

Allenandstatue2Lev Mendes at The Point:

The classic Woody Allen films possess something of the anxious intensity of youth (and a lot of the tormented eroticism of adolescence). But while the older director’s energy has certainly kept up—he continues to release, on average, a new film every year—a good deal of his early fervor has not. One gets the impression at times that for Allen filmmaking has become a kind of make-work, prized for its reflexive busyness above all. (Allen himself tends to reinforce this impression in interviews, as when he recently described directing as “a great distraction from the real agonies of the world.”) It is hardly surprising, then, that many of his later offerings have had a slighter, somewhat derivative air.In the much-maligned Anything Else (2003), for example, the whole image of New York and its highbrow inhabitants appeared out-of-touch and oddly passé. The film’s struggling young comedian lives in a beautiful Upper East Side walk-up and prattles on endlessly about psychoanalysis. The details were all wrong.

In light of this, it is easier to understand why viewers welcomed Allen’s Zelig-like transformation into an international director—his escape into a Europe of his own making. Yet, the films of the last decade also come through as less personally invested, their success increasingly dependent on the brilliance of Allen’s cinematographers and carefully chosen actors.

more here.

Monty Hall problem

From Wikipedia:

MontyThe Monty Hall problem is a probability puzzle, loosely based on the American television game show Let's Make a Deal and named after its original host, Monty Hall. The problem was originally posed in a letter by Steve Selvin to the American Statistician in 1975 (Selvin 1975a), (Selvin 1975b). It became famous as a question from a reader's letter quoted in Marilyn vos Savant's “Ask Marilyn” column in Parade magazine in 1990 (vos Savant 1990a):

Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, “Do you want to pick door No. 2?” Is it to your advantage to switch your choice?

Vos Savant's response was that the contestant should switch to the other door. (vos Savant 1990a) The argument relies on assumptions, explicit in extended solution descriptions given by Selvin (1975a) and by vos Savant (1991a), that the host always opens a different door from the door chosen by the player and always reveals a goat by this action—because he knows where the car is hidden. Leonard Mlodinow stated: “The Monty Hall problem is hard to grasp, because unless you think about it carefully, the role of the host goes unappreciated.” (Mlodinow 2008) Contestants who switch have a 2/3 chance of winning the car, while contestants who stick have only a 1/3 chance. One way to see this is to notice that, 2/3 of the time, the initial choice of the player is a door hiding a goat. When that is the case, the host is forced to open the other goat door, and the remaining closed door hides the car. “Switching” only fails to give the car when the player picks the “right” door (the door hiding the car) to begin with. But, of course, that will only happen 1/3 of the time. Many readers of vos Savant's column refused to believe switching is beneficial despite her explanation. After the problem appeared in Parade, approximately 10,000 readers, including nearly 1,000 with PhDs, wrote to the magazine, most of them claiming vos Savant was wrong (Tierney 1991). Even when given explanations, simulations, and formal mathematical proofs, many people still do not accept that switching is the best strategy (vos Savant 1991a). Paul Erdős, one of the most prolific mathematicians in history, remained unconvinced until he was shown a computer simulation confirming the predicted result (Vazsonyi 1999).

More here. (Note: Posting this interesting problem because it was correctly solved by the woman with the highest recorded IQ)