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11 Aug 19:53

Be Careful What You Wish For: Some Wild Speculation on Goodhart's Law and its Manifestations in the Brain

by Yohan John

by Yohan J. John

6a00d8341c562c53ef01bb086080af970d-800wiThis is the era of metrics: it seems that if we are to hack a path through the information jungle of the 21st century, we must be armed with an arsenal of scores, quantities, indices, factors, grades, and ratings. Our corporate and governmental overlords seem most comfortable parlaying in the seemingly objective language of numbers.

But can complex social and biological conditions be boiled down to scores? To GDP-per-capita, or a happiness index, or a body mass index? Social and biological metrics are attempt to quantify things that often seem unquantifiable: the overall health of a country or of a person, the ability of a school to educate its pupils, the quality of a consumer product, and even the aesthetic value of a movie, TV show, or musical album.

I've always been uncomfortable with this process of quantification: on the one hand  reducing any phenomenon to a single number seems like a major oversimplification, and on the other, the procedures for generating such numbers are often opaque. How exactly is inflation calculated? Or the cost of living? How do Nielson ratings work? Or the Netflix recommendation system? My discomfort with metrics began to crystallize and expand when I was introduced to a somewhat obscure "law" that should perhaps be more widely known outside of the dismal science that originated it.

Goodhart's Law was originally formulated as follows: "Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes." The word 'statistical' probably doesn't excite most people. But if we cut to the essence of what is being said, we find a rule of thumb (it's not a real law of nature) that might have implications well beyond the world of economics:

"When a measure becomes a target, it ceases to be a good measure."

Let's unpack this idea with a few examples. We can start with academic testing. Written examinations are a time-honored way to assess whether a student has learned something. But when tests scores become the metric by which to judge the performance of schools and teachers, then the connection between the test score and the quality of education often breaks down. This is because teachers "teach to the test", or even cheat in order to raise scores. By making test scores the target, rather than one among many factors that go into the assessment process, the people involved are incentivized to find the path of least resistance that leads to the highly specific targeted outcome. This drive to find the easiest route to higher test scores is what breaks the correlation between test scores and the more general goal of quality education. You can do well on a test because you have a degree of mastery of the subject, or because you were trained in a mechanical fashion to do the specific test, with no care given to your ability to apply what is learned in other potentially important contexts. [1]



Good examples of Goodhart's Law crop up because of search engine optimization. Early search engines ranked webpages based in part on their content. This was easily manipulated by dodgy websites that contained vast repetitive stretches of text specifically tailored to web-crawling algorithms. Google's PageRank system was a major innovation because it used links between websites, rather than content alone, as the metric for importance. The logic was that useful pages tend to receive lots of incoming links. But this too can be gamed: webmasters can engage in link trading to move their websites higher up in Google's search results. [2]

If there is more than one way to produce the desired metric, then the agents being measured — the schools, the markets, the websites — will game the system whenever possible to minimize their effort and discomfort. The net effect is a kind of social quantum mechanics: the act of observing a complex social system can disrupt it, and also break down the link between the metric and the system. For this breakdown to occur, specific conditions need to be met. First, the metric must be loose enough to confer a degree of play to the system: there must be more than on causal pathway leading from the system to the metric. High test scores can result from a solid understanding of the subject, or from "teaching to the test", or from outright cheating. Second, the metric must be used for some 'payout' purpose: the system being measured must feel the consequences of the metric. Websites that get more traffic get more ad revenue.

If a metric is connected to a payout, this creates a form of feedback in the system. This feedback in turn creates a selective pressure, or a drive towards competition, if the payout is a limited resource (like money or attention). The metric is a way for the 'measurer' (the school board, a company, a regulator) to declare its desires to the system, and therefore for the system to adapt to these desires in order to get paid. The goal might actually be high quality education, but because this is very difficult to assess in all its complexity, the easily-gamed metric of average test scores steps in as substitute for the elusive ideal. Some sort of 'objective' guide for getting to one's goal must be better than none at all, right? Perhaps, but be careful what you wish for, because it might not be what you were really wishing for.

In HG Wells's short story "The Truth About Pyecraft" (which you can read for free online here if you are worried about spoilers), a man named Pyecraft asks the narrator for a magical Oriental recipe to help him lose weight. But the recipe turns out to make him weightless, leaving his size and shape intact. After consuming the magical elixir, Pyecraft floats up to the ceiling like a helium balloon. The narrator concludes that Pyecraft has committed the "Sin of Euphemism": asking for a way to lose "weight" when what he really wanted to do was lose fat. One's weight normally has a fair correlation with the amount of fat in one's body, but in the universe Pyecraft inhabits, this relationship can break down. (Pyecraft has to weigh himself down with lead underwear in order to live a normal life from then onwards.) Euphemism is the use of a pleasant or neutral word to talk about something unpleasant. The "euphemistic" nature of Goodhart's Law is that we use an easy-to-measure number to target something hard to get a handle on. Unless we are very lucky indeed, most of the social metrics we come up with will give the system far too much leeway.

If Goodhart's Law were no more than a specific example of the more general tendency of humans to mess with institutions, then perhaps I would not be that interested in it. But I think that the conditions for Goodhart's Law — a multiplicity of causal pathways, feedback, and competition for limited resources — are not simply hallmarks of social networks. You can also discern these dynamics in neural networks. But in order to understand this, we will need to set up an extended metaphor for how the brain works.

The Neural Citadel

Nowadays we routinely encounter descriptions of the brain as a computer, especially in the pop science world. Just like computers, brains accept inputs (sensations from the world) and produce outputs (speech, action, and influence on internal organs). Within the world of neuroscience there is a widespread belief that the computer metaphor becomes unhelpful very quickly, and that new analogies must be sought. So you can also come across conceptions of the brain as a dynamical system, or as a network. One of the purposes of a metaphor is to link things we understand (like computers) with thing we are still stymied by (like brains). Since the educated public has plenty of experience with computers, but at best nebulous conceptions of dynamical systems and networks, it makes sense that the computer metaphor is the most popular one. In fact, outside of a relatively small group of mathematically-minded thinkers, even scientists often feel most comfortable thinking of the brain as a elaborate biological computer. [3]

However, there is another metaphor for the brain that most human beings will be able to relate to. The brain can be thought of as an economy: as a biological social network, in which the manufacturers, marketers, consumers, government officials and investors are neurons. Before going any further, let me declare up front that this analogy has a fundamental flaw. The purpose of metaphor is to understand the unknown — in this case the brain — in terms of the known. But with all due respect to economists and other social scientists, we still don't actually understand socio-economic networks all that well. Not nearly as well as computer scientists understand computers. Nevertheless, we are all embedded in economies and social networks, and therefore have intuitions, suspicions, ideologies, and conspiracy theories about how they work.

Because of its fundamental flaw, the brain-as-economy metaphor isn't really going to make my fellow neuroscientists' jobs any easier, which is why I am writing about it on 3 Quarks Daily rather than in a peer-reviewed academic journal. What the brain-as-economy metaphor does do is allow us to translate neural or mental phenomena into the language of social cooperation and competition, and vice versa. Even though brains and economies seem equally mysterious and unpredictable, perhaps in attempting to bridge the two domains something can be gained in translation. If nothing else, we can expect some amusing raw material for armchair philosophizing about life, the universe, and everything. [4]

So let's paint a picture of the neural economy. Imagine that the brain is a city — the capital of the vast country that is the body. The neural citadel is a fortress; the blood-brain barrier serves as its defensive wall, protecting it from the goings-on in the countryside, and only allowing certain raw materials through its heavily guarded gates — oxygen and nutrients, for the most part. Fuel for the crucial work carried out by the city's residents: the neurons and their helper cells. The citadel needs all this fuel to deal with its main task: the industrial scale transformation of raw data into refined information. The unprocessed data pours into the citadel through the various axonal highways.  The trucks carrying the data are dispatched by the nervous system's network of spies and informants. Their job is to inform the citadel of the goings-on outside its walls. The external sense organs — the eyes, ears, nose, tongue and skin — are the body's border patrols, coast guards, observatories, and foreign intelligence agencies. The muscles and internal organs, meanwhile, are monitored by the home ministry's police and bureaucrats, always on the look-out for any domestic turbulence. (The stomach, for instance, is known to be a hotbed of labor unrest.)

The neural citadel enables an information economy — a marketplace of ideas, as it were. Most of this information is manufactured within the brain and internally traded, but some of it — perhaps the most important information — is exported from the brain in the form of executive orders, requests and the occasional plaintive plea from the citadel to the sense organs, muscles, glands and viscera. The purpose of the brain is definitely subject to debate — even within the citadel — but one thing most people can agree on is that it must serve as an effective and just ruler of the body: a government that marries a harmonious domestic policy — unstressed stomach cells, unblackened lung cells, radiant skin cells and resilient muscle cells — with a peaceful and profitable foreign policy. (The country is frustratingly dependent on foreign countries, over which it has limited control, for its energy and construction material.)

The citadel is divided into various neighborhoods, according to the types of information being processed. There are neighborhoods subject to strict zoning requirements that process only one sort of information: visions, sounds, smells, tastes, or textures. Then there are mixed use neighborhoods where different kinds of information are assembled into more complex packages, endlessly remixed and recontextualized. These neighborhoods are not arranged in a strict hierarchy. Allegiances can form and dissolve. Each is trying to do something useful with the information that is fed to it: to use older information to predict future trends, or to stay on the look-out for a particular pattern that might arise in the body, the outside world, or some other part of the citadel.  Each neighborhood has an assortment of manufacturing strategies, polling systems, research groups, and experimental start-up incubators. Though they are all working for the welfare of the country, they sometimes compete for the privilege of contributing to governmental policies. These policies seem to be formulated at the centers of planning and coordination in the prefrontal cortex — an ivory tower (or a corporate skyscraper, if you prefer merchant princes to philosopher kings) that has a panoramic view of the citadel. The prefrontal tower then dispatches its decisions to the motor control areas of the citadel, which notify the body of governmental marching orders.

Let us briefly step away from the citadel metaphor to imagine a concrete situation where different parts of the brain might be saying different things, and therefore having to compete for access to the decision-making tower. Imagine you are in the jungle, and you are somewhat hungry, but also aware that there is a man-eating tiger on the loose. Let's say you find a source of food. Should you start eating, and therefore lower your guard slightly? Or should you stay vigilant, and wait to find a source of food in a safer location? It depends on a variety of factors: on metrics that the brain has either inherited or invented. If you stay hungry for too long you'll become weak, and then it will be much harder to deal with the tiger. But if you distract yourself through the process of eating, you might get eaten yourself.

The brain's metrics might be signals like the volume of animal noise in the jungle (which some say is an indicator of a tiger's proximity), or some estimate of the body's energy levels. Whenever you have two mutually exclusive courses of action, only one of them can win out. And the way the brain decides on one action versus another is by weighing those internal metrics. The brain areas and sub-areas that have proven consistently useful become increasingly able to communicate with the decision-making. In neuroscience we explicitly use the term 'credit assignment' to refer to how a neural network can pick out the neurons with most useful piece of information available, and allow them to have a stronger effect on decisions and actions. One of the mechanisms for this is called synaptic learning: the connections (synapses) between neurons can be strengthened or weakened depending on a variety of factors.

So going back to the citadel, we can make guesses about how payments work in the neural economy. Neurons and groups of neurons receive synaptic credit, which grants them more access to places up and down the organizational hierarchy. Good workers gain the trust of their bosses, co-workers and underlings, and can therefore more easily make their opinions heard. They also gain access to the best quality raw material — data arriving from elsewhere. Meanwhile, workers who aren't saying anything particularly useful or relevant to the context get less attention and less access. Success in the neural economy is much like success in a social network: it all boils down to the number and strength of connections. (Just having lots of connections is not the point, however. Quality and relevance matter. These connections must serve the distinctive goals of the neuron and the networks it is part of.) Whether neural connections are strengthened or weakened is a complex matter, and depends on wider forces including the neurochemical weather conditions.

A troubled neighborhood

Celebrity neurochemicals like dopamine, serotonin, and oxytocin can be thought of as indirect indicators of weather conditions — the temperature, the pressure, the humidity, the cloud cover — and they can have all kinds of effects on the neural citizenry, which tries to adapt to the ever-changing conditions. They can change the way a neuron talks, or modify the rules by which its connections with other neurons get regulated. Just as a meteorologist's instruments serve as a window on what the weather is and how it will develop in the near future, neurochemicals and hormones are used in the brain as metrics for signaling and assessing various situations in the brain and body.

Let's focus on one particular neural weathervane: dopamine. I've mentioned in a previous 3QD essay that dopamine has been mischaracterized as 'the pleasure chemical'. Dopamine doesn't just get released in response to pleasurable activities: it can also be released by negative experiences or by situations that are unpredictable. But dopamine does seem to have a powerful ability to change the decisions made by the brain as a whole. Drugs of abuse often affect the dopamine system. So researchers initially thought that drugs like cocaine or methamphetamine were just so pleasurable that the addicts simply couldn't resist them. The story turned out to be much more complicated.

Dopamine is not itself the chemical that engenders the subjective experience of pleasure. There may not be any single chemical that operates in such a simplistic way. What it might be is a kind of metric that the brain uses to represent some (still debated) class of potentially useful information. Dopamine has a strong ability to change the synapses between neurons. The chemical and informational highways that lead up to the dopamine cell neighborhood seem to allow dopamine cells to notify the rest of the brain of situations that are potentially worth paying attention to, and perhaps remembering for later.

So if you experience something pleasurable, like a taste of honey, you will probably want to know how you can repeat this experience. In order to do this you need to find out which pieces of information preceded the taste of honey. Perhaps it was the sounds of bees. Or the sight of a particular tree. A burst of dopamine seems to help form a link between certain kinds of information and their consequences. Once these links are made, the next time your circumstances resemble the happy honey discovery episode, you can begin to respond, perhaps ensuring that you get more honey than last time, or paying closer attention, so you can discover the precise source of the honey. More proactively, you may also be able to re-create those circumstances — by getting into beekeeping, for instance.

Remember that dopamine is not a direct mapping from honey to the brain. It is embedded in a complex causal web woven by the blind spider of natural selection. Evolutionary forces are under no compulsion to construct signaling pathways that convey one and only one thing. Natural selection is a satisficing process, so it creates situations that are good enough, but not necessarily the most efficient. Dopamine signaling was evidently good enough as a signal of potentially useful information for evolutionary forces to allow it to change synapses and bias our behavior. The raw data generated when honey arrives at the tongue and later the stomach travels along multiple roads that lead into the brain. One of those roads leads to the dopamine neighborhood. But the full subjective experience does seem to involve the consequences of all those other data streams.

When a drug starts to make trouble on the streets of the dopamine zone, it is very likely to be doing so through causal pathways that are distinct from the ones linking honey with dopamine. Because there is more than one way to get a dopamine cell to sound the alarm, dopamine's correlation with usefulness (or pleasure, or unpredictability) can easily break down. Drugs may have a pleasurable component, but addicts often talk about how the pleasure can fade away at some point, leaving only the compulsion to feed the addiction. It is at this point that we can import Goodhart's Law into our picture of the neural economy. Perhaps dopamine is a metric that the brain can use to assign credit to useful information, giving the neural sources of that information more access to the halls of power. But if dopamine stimulation becomes a target, it ceases to have a strong relationship with usefulness. It nevertheless retains its more mechanical ability to restructure neural networks through synaptic change. Direct dopamine stimulation might cause the brain's motivation system to skip the 'liking' stage and go straight to the 'wanting' stage.

For drug addicts, it seems that the feedback and competition in their neural networks has created a Goodhart-like scenario, in which behavior becomes focused on the self-reinforcing chemical stimulation of dopamine cells, rather than on a more holistic stewardship of brain, body and society. Circumstances that prevent such a holistic approach may actually plant the seeds of addiction. The famous Rat Park experiments suggest that rats will not become addicted to drugs of abuse — even if they do consume them occasionally — if they are placed in a stimulating environment with sufficient food and opportunity for social interaction. Social isolation may contribute to the overcast neurochemical skies that are most conducive to drug abuse. It may create a situation where chemical stimulation is the only signal that is loud and clear, with nothing healthy to compete with it for access to the decision-making centers.

The head and the heart

Addiction to drugs is just an extreme version of a 'neural Goodhart' situation that can happen to anyone. One of the things the human brain allows for is rational theorizing about the state of the world. Whatever else these theories are for, at the very least they should occasionally help a person navigate in the world. But if rationalizing per se becomes the focus of the theorizing, rather than usefulness or agreement with reality, then we might end up delusional, or paranoid, or in thrall to a conspiracy theory. In such situations apparent internal consistency becomes the only metric for the worth of an idea. Rationalizing can become less useful as a guide to behavior if it becomes the only target of behavior. A group of rogue neurons that specialize in rationalizing might hijack one of the brain's credit assignment centers, giving it the ability to pay other groups to adopt its dubious standards.

We might come up with more examples if we replace 'rationalizing' with other neurochemical signals, ideas, theories, or patterns of behavior. Almost anything can become a 'totalitarian' obsession and lead to the detriment of other modes of thought and forms of life. We can propose a neural Goodhart's Law, which we might as well call Good-head's Law: a neural or conceptual metric might cease to correlate with mental and bodily well-being if it becomes the dominant prism through which experience is viewed.

In allocating power based solely on some reductive measure of goodness or truth, a totalitarian government destroys diversity and create stereotypical internal yes-men. We might go on to define a fundamentalist as a would-be totalitarian: someone who takes very seriously some narrow and rigidly defined set of metrics of personal or social health, and attempts to remake the self or society in slavish accordance with this idealized image. On the personal level, the quantified self movement might confront such issues head on. Metrics for personal health — cholesterol levels, body mass indices, blood sugar levels — capture very broad and often poorly understood statistical correlations. Imagine a person whose goal is to be healthy, and rigidly defines health in terms of these numbers. This person might conceivably find specific drugs or exercise regimens that bring these numbers into their allegedly optimal levels. But there are always mental and social consequences to any change in behavior. If the drug and exercise regimen leads to anxiety or social isolation, it may have various adverse effects on health.

A person who follows a Mediterranean diet might have health indices in the right places, but the good health that accompanies these numbers may also depend on specific causal chains, such as the psychological, social and environmental conditions that frame the person's life. A person might be able to manipulate his or her health indices into the supposedly healthy zone, but in a more forced or anxiety-inducing way that could be counterproductive. Along with Good-head's Law we can propose a Good-heart's Law: health metrics might cease to correlate with good health if they become lifestyle goals.

I hope it's clear that almost everything I've written here is wildly speculative. Not all metrics are going to break down when they become targets — whether they're implicit metrics used by the brain or explicit metrics invented by governments and private companies. Some of them have a very close relationship with the things they are measuring. If you are interested in reducing the number of atoms in your body, then your mass in kilograms is an appropriate metric. If you are interested in controlling how hot a room is, then temperature is the ideal metric.

The Goodhart scenario arises in very specific situations. First, the metric must be trying to capture something that is hard to define — there must be some gap between what the measurer is actually interested in, and what is directly measured. Second, there must be more than one causal pathway that can give you the targeted value for the metric. In other words, there must be no necessary or one-to-one relationship between the metric and the phenomenon being studied. (This is almost always the case in complex networks.) Third, the metric must be used to give feedback in a competitive situation: to allocate limited resources —money, credit, energy, attention — in a neural or social network.  [5]

The letter of the law and the spirit of the law

Goodhart's Law and its (admittedly speculative) biological corollaries serve as a warning for us as we concede more and more power to the algorithmic management of our lives. People working in government, in the business world, and in academic research are increasingly confronting problems that have to do with network level phenomena: at the highest levels we are grappling with complex social, economic and ecological networks, and at the lowest level we are dealing with equally complex networks of neurons and proteins and genes. New metrics will increasingly be deployed to make sense of the ever expanding pool of Big Data. Already on Wall Street there are anonymous trading algorithms doing odd things for unclear reasons. Perhaps in the near future governments and large companies will scan social networks (or the bio-sensors that some people will voluntarily place on themselves) looking for signs of incipient public outrage. Their metrics and algorithms will be marketed to us as 'scientific' and 'objective' approaches to concepts that used to be described in the wishy-washy terms used by artists, humanities professors, and social workers.

Goodhart's Law tells us that if we are not careful about what we target in a complex network, we might end up with something that is not at all what we actually wanted. Perhaps it is simply an amusing quirk of networks — something that future researchers will do away with using better metrics. On the other hand, Goodhart's Law could be a warning for how technocrats might inadvertently lead us into an Orwellian world by convincing society to dispense with those old wishy-washy terms for what we actually want. "Liberty, equality, fraternity, peace… what do they mean? Give me a number!" If everyone is forced to adopt the simultaneously oversimplified and opaque language of  metrics, then we may gradually lose the ability to articulate what is missing.

Perhaps the lesson we can learn from Goodhart's Law is that there must be a difference between the spirit of the law and the letter of the law, and between the spirit of measurement and a specific metric [6]. In a democratic culture, a specific law is a concrete expression of some goal for the self and society. In a scientific culture a metric is a concrete quantification of some multifaceted state of a self or a society. Behind a specific metric there is often a vague awareness of a more complex reality: after all, this awareness is usually what motivates the creation of the metric in the first place. I think it is important not to abandon this awareness, however vague it is, once a metric arises to dispel it. The post-Enlightenment legal systems that structure our lives also arose from a vague awareness: a spirit or sensibility that drives us to become fitter, happier, more productive, and more perfect personalities and polities. We might call these forms of awareness the scientific spirit and the humanistic spirit. They both seem to arise from a common source: the impulse to transcend the material, social, political, and conceptual boundaries of the present moment. This drive towards transcendental novelty also gives rise to art, literature, poetry and music — those wellsprings that seem to provide us with our most resonant expressions of what a self or a society ought to look like. Perhaps our allegiance must be with this mysterious spirit that animates our arts, our laws, and our measurements, rather than with any particular — and therefore limited — manifestation of it.


______

Notes

[1] In India, the prestige of the Indian Institutes of Technology has lead vast numbers of students to prepare for the entrance exam in intensive coaching camps. These coaching centers train students to get into the IITs, but do not prepare them at all for the qualitatively different (and more difficult) academic challenge of the coursework that awaits them. Many of them quickly go from elation at having made the grade to depression and sometimes even suicide.

[2] Several examples that illustrate Goodhart's Law, including an amusing one from the Soviet Union, can be found here.

[3] For an excellent historical discussion of the various metaphors that have been used to describe the mind and brain, see John G. Daugman's essay Brain Metaphor and Brain Theory [pdf].

[4] The trick of seeing the human society as a macrocosmic body is used to great effect in a section of the song 'Maya' by the Incredible String Band.

The great man, the great man, historians his memory
Artists his senses, thinkers his brain
Labourers his growth
Explorers his limbs
And soldiers his death each second
And mystics his rebirth each second
Businessmen his nervous system
No-hustle men his stomach
Astrologers his balance
Lovers his loins
His skin it is all patchy
But soon will reach one glowing hue
God is his soul
Infinity his goal
The mystery his source
And civilization he leaves behind
Opinions are his fingernails


[5] Economic indicators often check off all three boxes, which is presumably why Goodhart's Law turned up in economics.

[6] The Indian mythologist Devdutt Pattanaik makes an interesting point about the spirit of the law and the letter of the law in a television presentation on the differences between the two great Indian epics, the Ramayana and the Mahabharata. In his opinion the Ramayana, which takes place in an innocent age, depicts a society that still remembers the spirit of the law. The Mahabharata, by contrast, describes events at a later and more corrupt age, when society has forgotten the spirit of the law, and clings to the letter of the law.

 

[Image from Wikipedia: Seventeenth-century plan of the fortified city of Casale Monferrato. The citadel is the star-shaped structure on the left.]

11 Aug 19:05

Discrete stochastic parametrization [Applied Mathematics]

by Chorin, A. J., Lu, F.
Many physical systems are described by nonlinear differential equations that are too complicated to solve in full. A natural way to proceed is to divide the variables into those that are of direct interest and those that are not, formulate solvable approximate equations for the variables of greater interest, and...
08 Aug 00:08

The ghost in the machine

by Alex Tabarrok

I visited two wonderful churches in Barcelona. The first, of course, was La Sagrada Familia. Ramez Naam put it best, this is “the kind of church that Elves from the 22nd Century would build.” I can’t add to that, however, so let me turn to the second church.

The Chapel Torre Girona at the Polytechnic University of Catalonia in Barcelona is home to the MareNostrum, not the world’s fastest but certainly the world’s most beautiful supercomputer.

BSCC

Although off the usual tourist path, it’s possible to get a tour if you arrange in advance. As you walk around the nave, the hum of the supercomputer mixes with Gregorian chants. What is this computer thinking you wonder? Appropriately enough the MareNostrum is thinking about the secrets of life and the universe.

In this picture, I managed to capture within the cooling apparatus a saintly apparition from a stained glass window.

The ghost in the machine.

ComputerSaint

Hat tip: Atlas Obscura.

08 Aug 00:00

Science Works: And The Deaf Hear Video

by Ronald Bailey

GalinskyLast week I met Pennsylvania State University research technologist Phillip Galinsky at Transhumanism Summer Camp at Juniata College. Galinsky gave a terrific talk on the recent advances in neurotechology. Galinsky later showed me his video And The Deaf Hear where he melds the power of art with the brilliance of technology. I asked him if it would be OK for me to post the video at Reason? He kindly consented.

Galinsky explains why he put together this one minute video containing footage of activation of cochlear implants and auditory brainstem implants. From Galinsky:

  • This is just a small example of the low hanging fruit that science has produced for modern artists, but which modern artists are not often using as subject matter for their work.
  • My intention is to use the emotional and glorifying power of music to bring the viewer into an emotional state that more closely resembles the emotional state of a deaf person gaining hearing.
  • Modern art culture must rediscover what Richard Wagner referred to as the “glorifying power of art”.  Art has been used for glorification of phenomena since its birth.  Art was the first neurotechnology and good art is still just as functional as a tool for behavioral change as it was when it began – our brains simply have not changed enough as of yet to resist the emotionally persuasive power of art.
  • Most artists today are used for advertising, and art has always been a tool for behavioral change.  Completely free modern artists tend to focus on negative topics, and it’s important to make negative art to bring attention to important negative issues.  However, we need to also embrace a more Roman attitude towards art, and glorify those subjects that are worthy of glorification, such as restoring hearing to the deaf.

Enjoy your weekend.

05 Aug 22:45

Uber drivers’ collective action problem

by Cathy O'Neil, mathbabe

I’ve been enjoying thinking about ways for Uber drivers to game the surge pricing algorithm at Uber. I don’t know how it works, exactly, but I’m going to imagine that it’s along these lines:

  • there are well-defined neighborhoods in a city. This seems to be corroborated by the way the Uber app works for both drivers and riders.
  • in a given neighborhood, there are two groups: people asking for a ride who haven’t yet been picked up, and drivers looking to give a ride.
  • If the number of riders is 5 more than the number of drivers, then it becomes a “surge zone” for some amount of time, say 30 minutes.

Of course, I made up the numbers 5 and 30, but I’m guessing it’s more or less of this form, and those particular values don’t matter for the rest of the discussion anyway.

So here the thing, Uber wants to keep their riders happy, but to do that they actually tend to want to avoid creating surge situations, since surge situations usually imply riders wait longer and pay more. On the other hand, Uber drivers prefer surges, since they get paid more, and sometimes much more.

That means Uber drivers have a great incentive to game the system and create artificial surges. One way they can do this is by waiting outside an area that might become surge, wait for it to become surge, and then go into that area and swoop up a rider.

But it would make a lot more sense for drivers to work together to do this. Imagine what would happen if all the drivers agreed to sit together in some central location, wait for surge pricing somewhere, and then assign people in order to go get those riders. Pretty much all the rides would become surge. Again, that wouldn’t make the riders happy, but it would benefit the drivers.

All they’d need to coordinate this is something like a walkie talkie system. Or an app. And oh, wait, such a thing already exists, and it’s called Blinkr (hat tip Alex Rosenblat). Instead of congregating in the same place, though, they had an even simpler idea, namely to turn off their Uber app, thus decreasing the local supply of drivers, then wait for surge pricing.

It’s something like an Uber strike, and it requires coordination, but I don’t think it’s illegal, right? I mean, Uber can’t fire them for doing this, since they aren’t employees, right?


04 Aug 18:27

Uncoupling synapses from the axon initial segment [Neuroscience]

by Wefelmeyer, W., Cattaert, D., Burrone, J.
The axon initial segment (AIS) is a structure at the start of the axon with a high density of sodium and potassium channels that defines the site of action potential generation. It has recently been shown that this structure is plastic and can change its position along the axon, as...
03 Aug 14:10

This Is What Controversies Look Like in the Twittersphere

A new way of analyzing disagreement on social media reveals that arguments in the Twittersphere look like fireworks.

Many a controversy has raged on social media platforms such as Twitter. Some last for weeks or months, others blow themselves in an afternoon. And yet most go unnoticed by most people. That would change if there was a reliable way of spotting controversies in the Twitterstream in real time.

01 Aug 21:32

Adaptation to sensory input tunes visual cortex to criticality

by Woodrow L. Shew
Nosimpler

I think I'm confused about what criticality means.

Nature Physics 11, 659 (2015). doi:10.1038/nphys3370

Authors: Woodrow L. Shew, Wesley P. Clawson, Jeff Pobst, Yahya Karimipanah, Nathaniel C. Wright & Ralf Wessel

A long-standing hypothesis at the interface of physics and neuroscience is that neural networks self-organize to the critical point of a phase transition, thereby optimizing aspects of sensory information processing. This idea is partially supported by strong evidence for critical dynamics observed in the cerebral cortex, but the impact of sensory input on these dynamics is largely unknown. Thus, the foundations of this hypothesis—the self-organization process and how it manifests during strong sensory input—remain unstudied experimentally. Here we show in visual cortex and in a computational model that strong sensory input initially elicits cortical network dynamics that are not critical, but adaptive changes in the network rapidly tune the system to criticality. This conclusion is based on observations of multifaceted scaling laws predicted to occur at criticality. Our findings establish sensory adaptation as a self-organizing mechanism that maintains criticality in visual cortex during sensory information processing.

31 Jul 22:02

Loss of Consciousness Is Associated with Stabilization of Cortical Activity

by Solovey, G., Alonso, L. M., Yanagawa, T., Fujii, N., Magnasco, M. O., Cecchi, G. A., Proekt, A.

What aspects of neuronal activity distinguish the conscious from the unconscious brain? This has been a subject of intense interest and debate since the early days of neurophysiology. However, as any practicing anesthesiologist can attest, it is currently not possible to reliably distinguish a conscious state from an unconscious one on the basis of brain activity. Here we approach this problem from the perspective of dynamical systems theory. We argue that the brain, as a dynamical system, is self-regulated at the boundary between stable and unstable regimes, allowing it in particular to maintain high susceptibility to stimuli. To test this hypothesis, we performed stability analysis of high-density electrocorticography recordings covering an entire cerebral hemisphere in monkeys during reversible loss of consciousness. We show that, during loss of consciousness, the number of eigenmodes at the edge of instability decreases smoothly, independently of the type of anesthetic and specific features of brain activity. The eigenmodes drift back toward the unstable line during recovery of consciousness. Furthermore, we show that stability is an emergent phenomenon dependent on the correlations among activity in different cortical regions rather than signals taken in isolation. These findings support the conclusion that dynamics at the edge of instability are essential for maintaining consciousness and provide a novel and principled measure that distinguishes between the conscious and the unconscious brain.

SIGNIFICANCE STATEMENT What distinguishes brain activity during consciousness from that observed during unconsciousness? Answering this question has proven difficult because neither consciousness nor lack thereof have universal signatures in terms of most specific features of brain activity. For instance, different anesthetics induce different patterns of brain activity. We demonstrate that loss of consciousness is universally and reliably associated with stabilization of cortical dynamics regardless of the specific activity characteristics. To give an analogy, our analysis suggests that loss of consciousness is akin to depressing the damper pedal on the piano, which makes the sounds dissipate quicker regardless of the specific melody being played. This approach may prove useful in detecting consciousness on the basis of brain activity under anesthesia and other settings.

27 Jul 20:25

Dido mutations trigger perinatal death [Neuroscience]

by Villares, R., Gutierrez, J., Futterer, A., Trachana, V., Gutierrez del Burgo, F., Martinez–A, C.
Nosimpler

wut

Nearly all vertebrate cells have a single cilium protruding from their surface. This threadlike organelle, once considered vestigial, is now seen as a pivotal element for detection of extracellular signals that trigger crucial morphogenetic pathways. We recently proposed a role for Dido3, the main product of the death inducer-obliterator (dido)...
24 Jul 17:22

Turning Bacteria Suspensions into Superfluids

by Héctor Matías López, Jérémie Gachelin, Carine Douarche, Harold Auradou, and Eric Clément

Author(s): Héctor Matías López, Jérémie Gachelin, Carine Douarche, Harold Auradou, and Eric Clément

Self-propelling bacteria can reduce the viscosity of a fluid to zero through a collective organization of their swimming.


[Phys. Rev. Lett. 115, 028301] Published Tue Jul 07, 2015

19 Jul 12:55

GenCyber

by woit

Over the years the NSF has financed various summer camps for high school students, designed to get them interested in mathematics or other areas of science. This summer they’ve teamed up with the NSA to deal with the problem of bad press due to the Snowden revelations by organizing a massive new program of quite different summer camps. The program is called GenCyber, and the New York Times today has an article about it here. This year the NSA/NSF is funding 43 camps (for a list, see here), with 1400 youngsters attending them, the plan is to expand to 200 camps over the next few years.

The NSA official in charge, Steven LaFountain explains how the PR aspect works:

Mr. LaFountain said the agency would not make sales pitches to campers, but hoped that the work of the agency would be enough to lure them into the field.

“We’re not trying to make these camps something to make people pro-N.S.A. or to try to make ourselves look good,” he said. “I think we’ll look good naturally just because we’re doing something that I think will benefit a lot of students and eventually the country as a whole.”

According to the New York Times, one sort of thing being taught is how to crack password files:

“We basically tried a dictionary attack,” Ben Winiger, 16, of Johnson City, Tenn., said as he typed a new command into John The Ripper, a software tool that helps test and break passwords. “Now we’re trying a brute-force attack.”

Others in the room stumbled through the exercise more slowly, getting help from faculty instructors who had prepped them with a lecture on the ethics of hacking. In other words, they were effectively told, do not try this at home.

“Now, I don’t want anybody getting in trouble now that you know how to use this puppy,” Darrell Andrews, one of the camp’s instructors, warned loudly. “Right? Right?” he added with emphasis.

Teaching thousands of kids how to crack password files? What could go wrong with that?

The program at Marymount features indoctrination visits to the NSA together with the hacking instruction, and one of the instructors seems to realize part of the problem:

And here at Marymount University, where campers are staying in dorms for their two-week program, visits to the N.S.A. and a security operations center break up classroom time.

The idea — and the challenge — of the camp, according to its head, Diana Murphy, a professor of information technology at Marymount, is to first teach students how to hack, so they can understand and defend against attackers they might encounter in cyberspace.

“It’s a fine balance for me as a teacher, because you have to teach them some of the hacking techniques, and layer that in with an ethical discussion,” Ms. Murphy said in an interview before camp began.

“They are most interested in the attacking things.”


Update
: CNN has an article up today about this here.

17 Jul 18:09

Friday A/V Club: Anarchists Take Over Film Industry, Make a Revolutionary Children's Musical

by Jesse Walker

On the gooooooood ship an-ar-chy...During the Spanish revolution of 1936, anarcho-syndicalists seized the movie studios and labs based in Barcelona and Madrid. In the ensuing years, they made radical documentaries, they made politically charged dramas, and, of course, they made a children's musical. Wait, what?

Yes, a children's musical. The anarcho-studios still needed to pay the bills, and that meant producing commercially viable entertainment along with the agitprop. Or, in this case, combining their commercially viable entertainment with their agitprop. In Nosotros somos asi, young Spaniards meet regularly for a sort of informal variety show at a boy's house, watching other kids sing, dance, recite a poem about a kitten, and even do a Busby Berkeley–style production number. These performances are intercut with scenes linked to the ongoing social revolution. There is talk of barricades. A boy's father is arrested, and then some children persuade an official to destroy the evidence against him. The rich kid sheds his class prejudices and develops a proletarian consciousness. Eventually the children have a big revolutionary meeting where the girls demand equal rights with the boys and a sign calls for less study time, more recess, and the abolition of arithmetic.

Unfortunately, the only subtitled version of the film that I could find was translated into French, not English. (The summary in the previous paragraph comes via my bad college Spanish, my worse high school French, and the judicious use of Google Translate.) But even if you can't understand a word of it, you should at least watch the introductory sequence, with children in different poses declaiming directly to the camera. And then, if you want to see the Busby Berkeley knockoff, you can skip to the 12:17 mark:

(For past editions of the Friday A/V Club, go here.)

16 Jul 12:15

Boolean logic with braids

by dmoskovich

First-off, I’m fairly chuffed that Tangle Machines (arXiv version HERE) was published in Proc. R Soc. A, and they even chose our figure for the cover! Computing with Coloured Tangles has also been accepted for publication. This is good.

One of the constructions of Tangle Machines, which I previously discussed HERE and HERE, is a universal set of logic gates using coloured tangles (and in fact we cheated, because our colouring wasn’t by a quandle but by a more general algebraic structure). It turns out that this idea isn’t new, and actually it’s been done better a long time ago in a different setting, and in a very nice way (thanks anonymous referee!). Boolean logic can be realized using coloured braids! And it’s even potentially useful in quantum computing! So today I’ll discuss this paper and the papers it references:

Alagic, G., Jeffery, S., and Jordan, S. Circuit Obfuscation Using Braids. In 9th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2014) (eds. S.T. Flammia and A.W. Harrow), Vol. 27, pp. 141–160.

We start with a group G in which we choose two elements, one which we call `zero’ and the other which we call `one’. Our operation is conjugation g \triangleright h = h^{-1}gh. A computation is a braid coloured by elements of G, with strands incident to endpoints at the bottom x_1, x_2,\ldots, x_k each of which is coloured by a zero or a one called the input of the computation, and strands incident to endpoints at the top y_1, y_2,\ldots, y_l each of which is coloured by a zero or a one called the output of the computation. The braid may also have additional strands at the top and bottom (indeed it must if k\neq l). These extra strands, called ancilla, may be coloured by any element of G. The ancilla serve as catalysts for the computation and nothing more.

How does a braid compute? Moving up through the braid from bottom to top, we encounter braid group generators \sigma_i describing strand i crossing over strand i+1, and their inverses. If the colour of strand i at the bottom of \sigma_i is h and the colour of strand i+1 at the bottom of \sigma_i is g, then the colour of strand i+1 at the top is still h while the colour of strand i at the top is g\triangleright h.

What computations can a braid perform? A-priori, we might suspect that maybe it can’t do all that much, because conjugations are rather special operations. In particular, it doesn’t seem like we should be able to realize an AND gate with a braid. To remind you, a\wedge b, pronounces `a and b‘, returns ab\bmod 2. So it returns 1 if both a and b are one, and zero otherwise. The reason AND seems really hard to realize using coloured braids (try it if you don’t believe me!) is that it responds differently to ones than to zeros, so there is an `if’ concept built in; and how could a braid do that? More formally, it’s recovering a product from conjugation, which seems impossible.

It really looks like one should be able to prove that AND can’t be realized by braids, and this is what people indeed believed for a long time. This is one case in which our intuition is wrong, however. Kitaev showed that if the group G is the symmetric group S_5, then AND can indeed be realized by a G-coloured braid (note: ancilla are important- this, and the fact that A_5 is `sufficiently rich’, is what comes to the rescue). The proof is pretty similar to a celebrated result of Barrington and of Krohn-Maurer-Rhodes about representing maps G^n\rightarrow G using conjugations. Ogburn and Preskill showed that the alternating group A_5, which is half as large as S_5, is enough.

Monchon constructed a Toffoli gate braid, which is explicitly drawn in Appendix A of Alagic-Jeffery-Jordan. It has 132 crossings and 14 strands (11 of which are ancilla), so it isn’t an easy construction.

To remind the reader, a Toffoli gate is a universal reversible logic gate which contains within it a universal set of gates. Thus, an AND gate is a subcomputation of a Toffoli gate. A Toffoli gate accepts 3 bits a, b, and c, returns a and b, and inverts c if and only if a=b=1.

Explicitly, (345)\in A_5 encodes zero and (435)\in A_5 encodes one. You can see the construction there.

There are some obvious questions which this raises- as any binary boolean function can be realized by a coloured braid (this is what the above result shows), and because the boolean circuit model is Turing complete, we know that any computable function can be represented by an A_5-coloured braid with ancilla. It’s pretty clear, however, that it would be tremendously suboptimal to realize individual Toffoli gates and to string them all together- the braid language can recover boolean circuits, but not in a simple or intuitive way. How could a simple braid computation be performed? What is the simples braid that would realize some given binary boolean function, and how would we set-out to find it? Is the group A_5 the best possible, or are there more reasonable groups (in whatever sense) which do the same job?

How is all of this practical? Well, an element in the braid group can be thought of as a motion of points in a disc (more accurately, as an element of the fundamental group of a configuration space on the disc). The timelines of these moving points trace out the braid- for instance, if we have three points, one of which is stationary and two of which change places, we obtain \sigma_1 (or its inverse) in the braid group on 3 strands.

Now imagine 2-dimensional particles- anyons they are called, and they are just-about physical- which move around one another in a disc. Say they have 60 states, and when one moves around another it picks up a phase which corresponds to the conjugation operation. Again, this is just about physical. Then voilá! The above construction gives rise to a Toffoli gate A_5-coloured braid!

There’s more to the story. We can use braid relations, AKA Reidemeister moves on braids, to obfuscate or to disguise our computation for security purposes, so an eavedropper with access to the system would have trouble figuring out which computation was being performed.

Computing seems to have a definite topological side, which is only just now slowly emerging into the light. The visionary who first saw this was Kauffman. There are many sides to the story, and I’m sure that topology appears in many different and even independent ways; a Toffoli gate braid is a particularly pretty one.


14 Jul 14:20

The Shadowy World of Cybersecurity Mercenaries

by Andrea Castillo

While the dangerous breadth of modern state surveillance has been rightfully exposed by whistleblowers like Edward Snowden, many of the forces that allow this underhanded Internet spying have gone remarkably unnoticed. In fact, an unexplored world of private sellers surreptitiously collaborates with intelligence agencies to help maintain their expansive snooping apparatuses. These security agents for our digital panopticon receive virtually no scrutiny thanks to their privileged, yet nuanced, relationships with powerful groups (and subsequent lack of mainstream-media coverage). But this month, the shadowy world of mercenary exploit sales finally had its huge Snowden moment.

In early July, an activist hacker known as "PhineasFisher" effortlessly infiltrated the systems of a notorious Italian zero-day exploit seller, called "Hacking Team." ("Zero day" refers to security vulnerabilities that are unknown to vendors, which "exploit sellers" often make available to the highest bidder.) PhineasFisher dumped 400 Gigabytes of documentation online for the world to browse. The trove confirmed what many in the security community had long suspected, including bombshell revelations that Hacking Team maintained business relationships with almost 40 different governments including the United States and Russia, sold spyware to brutal dictatorial regimes, and sold products that directly targeted journalists, software developers, and activists for surveillance and monitoring.

The transparency imposed on the rogue Hacking Team was incredibly valuable on its own; in fact, one of the company’s own vendors has called it a "blessing in disguise" to shed light on the industry and begin a discussion of zero-day sales reform. But the Hacking Team hack also provides important lessons about the broader security ecosystem and the thinning line between private and public entities as we adapt to the age of hacking without borders.

The Hacking Team was typical of an above-ground business operating legally in the exploit market. Like Germany’s Trovicor, France’s Amesys, the UK’s BlueCoat, and previous PhineasFisher target Gamma International, Hacking Team profits by selling exploits of popular computer software to powerful groups under the guise of "cybersecurity." When firms offer to look for and report any vulnerabilities so the firm that hired them can patch up and improve their software, this can be a wholly legitimate and beneficial trade. Often, however, these groups merely sell governments different ways to spy on or manipulate political enemies and even innocent citizens.

Indeed, the difference between these kinds of groups and the more stereotypical, hoodie-wearing, lone wolf hacker-for-hire is often one of style rather than ethical substance. Both of these groups make money by discovering or purchasing unknown computer bugs and selling them to governments, political parties, or even terrorist groups for a healthy mark-up.

Zero-day vulnerabilities are incredibly useful to parties wishing to unknowingly manipulate other people online. They are a bit like having a monopoly on a secret entrance to a popular computer program that only you know about. Zero-days can be exploited to remotely inserted malware or spyware that will activate anytime a user sends an online payment or updates iOS or runs Adobe Flash Player. (Incidentally, it might be a good idea to uninstall Flash for now, since we now know Hacking Team sold not one but two Flash exploits.) Other times, exploit merchants use vulnerabilities that are already known and target people running older, unpatched versions of popular software instead. This type of exploit service constituted the bulk of Hacking Team’s portfolio.

The trade in software exploits to further government surveillance is troubling enough from a privacy perspective. Activist groups such as the Electronic Frontier Foundation (EFF) and Reporters Without Borders have long criticized such practices for violating human rights and expanding the global net of digital surveillance.

But there are grave security implications as well. Selfishly hoarding zero-day vulnerabilities intentionally ensures that the Internet will remain systemically insecure. Going a further step and exploiting any kind of vulnerability for political surveillance or oppression could potentially introduce catastrophic weaknesses beyond the scope that the initial exploiters ever anticipated. A responsible netizen finds a zero-day and reports it to the public so that we can all be more secure. An unscrupulous sociopath sells it to Ethiopia for $1 million to crack down on U.S. journalists and wreck huge parts of the Internet in the process.

Security researchers pored through the Hacking Team document-dump on Wikileaks to determine which software vulnerabilities Hacking Team was selling so they could warn the public about which products needed to be updated or uninstalled. They have found three zero-days so far: the two Flash bugs and another for the Windows kernel. While those who practice good cyber hygiene will be able to inoculate themselves against these revealed exploits, the vast majority of less sophisticated Internet users may still be vulnerable to attack as prepackaged "exploit kits" of all three bugs are being sold to newbie hackers.

It is clear that "security" was far from the top priority for Hacking Team because their own security sucked. Hacking Team was not a sophisticated cybercastle whose alligator-filled moat nonetheless failed, it was an inflatable bounce-house with a paperclip lock. Their password was "P4ssword"—when it wasn’t "wolverine," "universe," or "Pssw0rd," that is. In the middle of a sensitive email exchange with an outside associate, Hacking Team COO Giancarlo Russo suddenly remembers to ask, "Do you have PGP [email encryption] by the way? We really do need to encrypt these emails." This one moment of late foresight is far outweighed by the firm’s incomprehensive encryption and poor user operational security.

By not-so-secretly stockpiling destructive exploits and engaging in ample public boasting, Hacking Team was more or less begging to be attacked. Their one-stop-shop arsenal of poorly-protected cyberweapons proved too tempting a target for rival hackers. Really, Hacking Team CEO David Vincenzetti should have known better. A veteran of the anti-authoritarian, pro-privacy Cypherpunk hacking movement, Vincenzetti cut his radical teeth developing a "file tampering detector" that would identify and repel intruders like Hacking Team from computer systems in 1992.

But Vincenzetti has changed quite a bit since the days when he participated in the same listservs as Wikileaks founder Julian Assange and EFF co-founder John Gilmore. His security chops have certainly suffered. Despite being an early promoter of email-encryption software, emails show that Hacking Team hardly used PGP at all.

More fundamentally, the "freedom hacker turned government tool" angle of the Hacking Team story reveals the unfortunate incentive structure presented to the tiny elite of hackers capable of building—or breaking—the global surveillance network that tracks our every online move. They can choose to fight or expose the system, risking media demonization, foreign asylum, and even lifelong prison sentences for the heinous crime of defending our freedoms online. Or they can sell out and enjoy fat retirements as cyberweapons dealers of choice for the world’s repressive states. Either way, this episode is an important reminder that the enemies of an open Internet are not limited to the state. 

09 Jul 20:04

Communist Crucifix Too Far for Pope Francis

by Ed Krayewski

Bolivian President Evo Morales gave Pope Francis a crucifix fashioned in the form of a Communist hammer-and-sickle during Francis' stop there. The Argentinian pope is on his first trip to South America since assuming the papacy, and did not appear pleased, murmuring "no está bien eso" and shaking his head.

You can watch the gift exchange below:

The Vatican tried to distance the pope from his objection. The hammer-and-sickle crucifix was a replica of one created by a Spanish Jesuit killed by the Bolivian government in 1980. The Catholic News Agency reports:

At a July 9 press briefing the Holy See press officer, Fr. Federico Lombardi, noted the lack of clarity in the audio of the exchange, and remarked that Pope Francis had been unaware the crucifix was a replica of Fr. Espinal's.

He also claimed that Fr. Espinal's use of it was not ideological but expressed a hope for dialogue between communism and the Church, adding that Pope Francis' remark likely expresed a sentiment of "I didnt' know", rather than "This is not right."

Other Catholics ween't as accommodating:

Catholics from various Hispanophone countries rejected Morales' gesture, considering it offensive to the numerous victims of terrorist groups in Latin America and of the historical totalitarian communist regimes.

Bishop Jose Munilla Aguirre of San Sebastián, a Spaniard, tweeted: "The height of arrogance is to manipulate God in the service of atheistic ideologies … Today, once again: #ChristCrucified".

Around the world, the left's become excited about the pope's latest encyclical, specifically and exclusively portions about climate change and environmental stewardship. The pope curried that kind of selective support by tapping anti-capitalist Naomi Klein for upcoming climate talks. But, as A. Barton Hinkle wrote earlier this week, the left's embrace of religious justification for public policy only applies when it leads to bigger government.

09 Jul 13:07

Unsustainable

by noreply@blogger.com (Atrios)
A few years ago I was on retirement savings panel at a conference. My designated role was to be the "MOOOOAR SOCIAL SECURITY" guy because of course. But the point I was trying to make to the more private savings folks was...how do you expect people to start their careers with a hundred thousand dollars in debt, and then save for a downpayment, and then save for retirement. This is unpossible even with high paying jobs, which most people don't have. It's true that the magic of compound interest works really well if you start saving at age 21 and continue until retirement, but it's also true that it's stupid to save if investment returns are lower than the interest rates on the absurd amount of debt that you were supposed to rack up to enter civilized life. Really no one should go into this much debt to go to college, but The Kids Today don't even have the option of cheap public universities like The Kids In My Day did. They're cheaper then private schools, but not by much.
Democratic presidential hopeful Martin O’Malley plans Wednesday to put forward an ambitious five-year goal of allowing students to graduate debt-free from public colleges and universities across the country.

The proposition is deeply personal for O’Malley: Aides say he and his wife have already incurred $339,200 in loans to put the two eldest of their four children through private universities. And college affordability was a leading priority for O’Malley during his tenure as Maryland’s governor.

Those who mock The Kids Today enrage me. Us olds had access to cheap public universities and we took that away from them. Also, too, gave them a shitty job market. Still let's laugh about their beards and their tattoos and their ipods and their hippity hop and how lazy they are! Silly Kids Today. So lazy. Such silly interests. And all that debt! So irresponsible.
07 Jul 18:39

Is an explicit $c$ known to lead to a noncomputable Julia set?

by Joseph O'Rourke

Braverman & Yampolsky have shown that there exist noncomputable Julia sets, i.e., there exist $c \in \mathbb{C}$ such that the Julia set of $f(z) = c + z^2$ is not computable. "A set is computable, if, roughly speaking, its image can be generated by a computer with an arbitrary precision."

Braverman, Mark, and Michael Yampolsky. "Non-computable Julia sets." Journal of the American Mathematical Society (2006): 551-578. (PDF download.)

My questions are:

Q. Is an explicit such $c$ known? A computable $c$?

It seems likely these questions are answered, perhaps in the cited paper. If anyone is familiar enough with this line of work to answer, I'd appreciate it.


Answered. The question is answered in the paper Igor identified, particularly in its full version:

Braverman, Mark, and Michael Yampolsky. "Computability of Julia sets." arXiv link. 2007.

They prove there exist computable $c \in \mathbb{C}$ such that the Julia set of $c + z^2$ is not algorithmically computable, and provide an algorithm for computing such a $c$. Under the assumption of a complex dynamics conjecture (due to Buff & Chéritat), they obtain a polynomial-time algorithm for computing such a $c$, i.e., $n$ bits of $c$ can be computed in time polynomial in $n$.

No explicit $c$ is known, as far as I can tell. (Their algorithms would not be easy to implement.)

07 Jul 18:21

Fullerene C_{60} Simulated with a Superconducting Microwave Resonator and Test of the Atiyah-Singer Index Theorem

by B. Dietz, T. Klaus, M. Miski-Oglu, A. Richter, M. Bischoff, L. von Smekal, and J. Wambach

Author(s): B. Dietz, T. Klaus, M. Miski-Oglu, A. Richter, M. Bischoff, L. von Smekal, and J. Wambach

A centimeter sized superconducting buckyball made from lead and brass is used to simulate the spectral properties of C60.


[Phys. Rev. Lett. 115, 026801] Published Mon Jul 06, 2015

06 Jul 17:13

Babbler birds babble non-babble

by Tyler Cowen

A study of the chestnut-crowned babbler bird from Australia revealed a method of communicating that has never before been observed in animals.

The bird combines sounds in different combinations to convey meaning.

The findings could help in the understanding of how language evolved in humans, researchers report in the online journal PLOS Biology.

Co-researcher Dr Andy Russell from the University of Exeter said: “It is the first evidence outside of a human that an animal can use the same meaningless sounds in different arrangements to generate new meaning.

“It’s a very basic form of word generation – I’d be amazed if other animals can’t do this too.”

There is more here.  You will find further coverage here.

01 Jul 19:52

Braiding a Flock: Winding Statistics of Interacting Flying Spins

by Jean-Baptiste Caussin and Denis Bartolo

Author(s): Jean-Baptiste Caussin and Denis Bartolo

Individual birds flying in a flock do not fly in straight lines, but weave in and out of each other. Topological invariant braiding statistics shows that this weaving has a coherent rotation: the birds create a braid.


[Phys. Rev. Lett. 114, 258101] Published Tue Jun 23, 2015

25 Jun 19:12

Acetaminophen - over the counter relief from both pain and emotions...

by mdbownds@wisc.edu (Deric Bownds)
I've sometimes wondered why I feel a bit flat (anhedonic) after taking acetaminophen (Tylenol). Durso et al. show that it blunts sensitivity to both negative and positive stimuli.
Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals’ reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals’ reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals’ evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals’ evaluative and emotional processing, irrespective of negative or positive valence.
25 Jun 19:11

Churches against Prohibition

by Alex Tabarrok

The New England Conference of United Methodist Churches, a group of 600 churches, has issued a resolution calling for an end to the war on drugs. The resolution draws on ethical principles and also a remarkably astute reading of economics and social science:

Whereas: The public policy of prohibition of certain narcotics and psychoactive substances, sometimes called the “War on Drugs,” has failed to achieve the goal of eliminating, or even reducing, substance abuse and;

Whereas: There have been a large number of unintentional negative consequences as a result of this failed public policy and;

Whereas: One of those consequences is a huge and violent criminal enterprise that has sprung up surrounding the Underground Market dealing in these prohibited substances and;

Whereas: Many lives have been lost as a result of the violence surrounding this criminal enterprise, including innocent citizens and police officers and;

Whereas: Many more lives have been lost to overdose because there is no regulation of potency, purity or adulteration in the production of illicit drugs and;

Whereas: Our court system has been severely degraded due to the overload caused by prohibition cases and;

Whereas: Our prisons are overcrowded with persons, many of whom are non-violent, convicted of violation of the prohibition laws and;

Whereas: Many of our citizens now suffer from serious diseases, contracted through the use of unsanitary needles, which now threaten our population at large and;

Whereas: To people of color, the “War on Drugs” has arguably been the single most devastating, dysfunctional social policy since slavery and;

Whereas: Huge sums of our national treasury are wasted on this failed public policy and;

Whereas: Other countries, such as Portugal and Switzerland, have dramatically reduced the incidence of death, disease, crime, and addiction by utilizing means other than prohibition to address the problem of substance abuse and;

Whereas: The primary mission of our criminal justice system is to prevent violence to our citizens and their property, and to ensure their safety, therefore;

Be it Resolved: That the New England Annual Conference supports seeking means other than prohibition to address the problem of substance abuse; and is further resolved to support the mission of the international educational organization Law Enforcement Against Prohibition (LEAP) to reduce the multitude of unintended harmful consequences resulting from fighting the war on drugs and to lessen the incidence of death, disease, crime, and addiction by ending drug prohibition.

18 Jun 16:53

A bit of amphetamine turns older brains into younger brains.

by mdbownds@wisc.edu (Deric Bownds)
Fascinating. Garrett et al. show that raising dopamine levels with amphetamine (sold as the prescription drug Adderall, for ADHD), increases the brain wave variability that enhances working memory, so that seniors perform as well as younger people on the n-back working memory test. (Common prescription doses of 5-30 mg act as a cognitive enhancer.
Higher doses can be aphrodisiac, euphoriant, addictive, and have many bad side effects.) I pass on both their statement of significance and abstract. Also, a figure that tempts me to try to get an adderall prescription and do a self experiment.
Significance
Younger, better performing adults typically show greater brain signal variability than older, poorer performers, but the mechanisms underlying this observation remain elusive. We attempt to restore deficient functional-MRI–based blood oxygen level-dependent (BOLD) signal variability (SDBOLD) levels in older adults by boosting dopamine via d-amphetamine (AMPH). Notably, older adults met or exceeded young adult SDBOLD levels under AMPH. AMPH-driven changes in SDSDBOLD also predicted AMPH-driven changes in reaction time speed and variability on a working memory task, but depended greatly on age and drug administration order. These findings (i) suggest that dopamine may account for adult age differences in brain signal variability and (ii) highlight the importance of considering practice effects and state dependencies when evaluating the neurochemical basis of age- and cognition-related brain dynamics. 
Abstract
Better-performing younger adults typically express greater brain signal variability relative to older, poorer performers. Mechanisms for age and performance-graded differences in brain dynamics have, however, not yet been uncovered. Given the age-related decline of the dopamine (DA) system in normal cognitive aging, DA neuromodulation is one plausible mechanism. Hence, agents that boost systemic DA [such as d-amphetamine (AMPH)] may help to restore deficient signal variability levels. Furthermore, despite the standard practice of counterbalancing drug session order (AMPH first vs. placebo first), it remains understudied how AMPH may interact with practice effects, possibly influencing whether DA up-regulation is functional. We examined the effects of AMPH on functional-MRI–based blood oxygen level-dependent (BOLD) signal variability (SDBOLD) in younger and older adults during a working memory task (letter n-back). Older adults expressed lower brain signal variability at placebo, but met or exceeded young adult SDBOLD levels in the presence of AMPH. Drug session order greatly moderated change–change relations between AMPH-driven SDBOLD and reaction time means (RTmean) and SDs (RTSD). Older adults who received AMPH in the first session tended to improve in RTmean and RTSD when SDBOLD was boosted on AMPH, whereas younger and older adults who received AMPH in the second session showed either a performance improvement when SDBOLD decreased (for RTmean) or no effect at all (for RTSD). The present findings support the hypothesis that age differences in brain signal variability reflect aging-induced changes in dopaminergic neuromodulation. The observed interactions among AMPH, age, and session order highlight the state- and practice-dependent neurochemical basis of human brain dynamics.
Figure. Increased BOLD variability and improved cognitive performance under AMPH. Multivariate partial least-squares model of relation between SDBOLD, Age Group, AMPH, and Task Condition. Higher brain scores reflect higher BOLD signal variability. Error bars represent bootstrapped 95% confidence intervals (1,000× with replacement). Brain images are plotted in neurological orientation (left is Left). AMPH, amphetamine; BSR, bootstrap ratio.

13 Jun 14:28

Deep Learning Machine Beats Humans in IQ Test

Computers have never been good at answering the type of verbal reasoning questions found in IQ tests. Now a deep learning machine unveiled in China is changing that.

13 Jun 13:53

Isometric sketching of any set via the Restricted Isometry Property

by Igor
 
 
In compressive sensing, the earliest results used randomization as a way to compress signals. But it is in fact deeper. This week, we saw in Extreme Compressive Sampling for Covariance Estimation that sparsity was not central to the argument of dimension reduction. Here is another paper that further enlighten us on this very specific issue. From the paper:
At the heart of our analysis is a theorem that shows that matrices that preserve the Euclidean norm of sparse vectors (a.k.a. RIP matrices), when multiplied by a random sign pattern preserve the Euclidean norm of any set. Roughly stated, linear transforms that provide low distortion embedding of sparse vectors also allow low distortion embedding of any set! We believe that our result provides a rigorous justification for replacing “slow” Gaussian matrices with “fast” and computationally friendly matrices in many scientific and engineering disciplines. Indeed, in a companion paper [18] we utilize our results in this paper to develop sharp rates of convergence for various optimization problems involving such matrices.
my emphasis.


 

Isometric sketching of any set via the Restricted Isometry Property by Samet Oymak, Benjamin Recht, Mahdi Soltanolkotabi

In this paper we show that for the purposes of dimensionality reduction certain class of structured random matrices behave similarly to random Gaussian matrices. This class includes several matrices for which matrix-vector multiply can be computed in log-linear time, providing efficient dimensionality reduction of general sets. In particular, we show that using such matrices any set from high dimensions can be embedded into lower dimensions with near optimal distortion. We obtain our results by connecting dimensionality reduction of any set to dimensionality reduction of sparse vectors via a chaining argument.
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12 Jun 16:32

When we teach robots to to fish, do all men starve?

by David Seaton's Newslinks
Scott Santens describes himself as:
"Citizen of Earth and New Orleans. Writer and advocate of basic income for all. Bachelor of Science in Psychology. Member of the U.S. Basic Income Guarantee Network, moderator of the /r/BasicIncome community on Reddit, and founder of The BIG Patreon Creator Pledge. — @2noame" 
Mr Santens is a leading militant in the basic income movement, which, to simplify brutally, advocates all citizens receiving enough money to live decently, merely because they are human... even if they are permanently unemployed and probably unemployable. A condition which  in the foreseeable future, if we examine the advances in robotics and information technologies, may be the status of almost everyone in  the world... outside the sex industry, or the owners of the means of production themselves.

Without too much exaggeration, this could be considered the greatest change in the human condition since the Agricultural Revolution.

Because for the last 12,000 years, except for a few aristocratic layabouts of inherited wealth, the destiny of all human beings: men, women and children, has been to work hard, very, very, hard.
"In the sweat of thy face shalt thou eat bread"
Genesis 3:19
For centuries, enlightened individuals have believed that education was the solution for advancing humanity. I'm sure you are all familiar with the famous quote of the medieval Jewish philosopher from Cordoba, Maimonides:
"Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime."
Maimonides
The genius of Scott Santens has been to take Maimonides' dictum and turn it into the following riddle to describe mankind's present and future situation:

"When we teach robots to fish, do all men starve, or do all men eat?"  

For make no mistake, the equation, work = life, is hard wired into our civilization.

For even when we were with you, this we commanded you, that if any would not work, neither should he eat.
Saint Paul: 2 Thessalonians 3:10

Just in case you think you can dismiss Saint Paul as representing a "rightwing" mind set, check the following:
"In the USSR work is a duty and a matter of honor for every able-bodied citizen, in accordance with the principle: “He who does not work, neither shall he eat.”
Try to make a sincere self-examination: if in a future robot-IT driven world, you somehow managed to have a remunerative job, would you be willing to support an enormous mass of unemployable people? Certainly it would put your empathy to a severe test to do so.  And if you,  as a mere worker, would make that sacrifice... How willing do you think the owners of all the robots and the IT would be to share their wealth too? To get an idea, try asking the Koch brothers.

This is really not a question for a dystopian, Sci-Fi film. We have living models with us today of how the world of the future will probably look. 

The other day a friend sent me a link to a wonderful article in The New Yorker about the capital of Angola, Luanda, which in my opinion, describes what the world of mega-inequality will probably look like in only a few short decades... if some cataclysmic social change doesn't take place before then. 

It's a long article and I recommend reading it all, but I've extracted some of the meat from it to give you a general idea.
For the past two years, Luanda—not Tokyo, Moscow, or Hong Kong—has been named, (...) as the world’s most expensive city for expatriates.(...) The country now produces 1.8 million barrels of oil a day(...)The boom has transformed a failed state into one of the world’s fastest-growing economies.(...) Almost nothing is made in Angola, so nearly every car, computer, crate of oranges, tin of caviar, jar of peanut butter, pair of bluejeans, and bottle of wine arrives by boat. Every day, a trail of container ships backs up from the port through the Bay of Luanda and out into the sea.(...) Grotesque inequality long ago became a principal characteristic of the world’s biggest and most crowded cities. But there is no place quite like Luanda, where a bottle of Coke can sell for ten dollars(...). Per-capita income in Angola has nearly tripled in the past dozen years, and the country’s assets grew from three billion dollars to sixty-two billion dollars. Nonetheless, by nearly every accepted measure, Angola remains one of the world’s least-developed nations. Half of Angolans live on less than two dollars a day, infant mortality rates are among the highest in the world, and the average life expectancy—fifty-two—is among the lowest. (...) Nearly half the population is undernourished, rural sanitation facilities are rare, malaria accounts for more than a quarter of all childhood deaths(...). One businessman famously distributed Rolexes to guests as party favors at a wedding. Each member of parliament recently received a new hundred-thousand-dollar Lexus. Isabel dos Santos, the President’s forty-two-year-old daughter, is typically described as the richest woman in Africa; Forbes puts her net worth at more than three billion dollars. (...) In 2011, as president of the Red Cross, dos Santos paid Mariah Carey a million dollars to perform for two hours at the organization’s annual gala. (...)Hotels, luxury apartment buildings, shopping arcades, and modern office complexes compete for space in the city center with shantytowns made from corrugated tin and heavy cardboard and with tens of thousands of people who live on mounds of dirt, in the scrapped remains of rusted and abandoned vehicles, or out in the open, next to fetid, unused water tanks.  Extreme City - The New Yorker  
The article will print out to about twelve pages and every one is filled with dozens of grotesque examples similar to the ones I have chosen.

In the article we have the answer to Scott Santens' marvelous riddle, "when we teach robots to fish, do all men eat or do all men starve?".

To paraphrase Marie Antoinette:

"If the people have no fish, let them eat cake"  

DS
11 Jun 17:48

Spatial distribution of thermal energy in equilibrium

by Yohai Bar-Sinai and Eran Bouchbinder

Author(s): Yohai Bar-Sinai and Eran Bouchbinder

According to the equipartition theorem, in a classical system at equilibrium, thermal energy is equally distributed among the degrees of freedom appearing as quadratic forms in the Hamiltonian. Asking the question what is the spatial distribution of the thermal energy, the authors find a general upper bound and show that the details depend on dimensionality, interactions, and disorder.


[Phys. Rev. E 91, 060103(R)] Published Tue Jun 09, 2015

11 Jun 16:54

The market for your personal data is maturing

by Cathy O'Neil, mathbabe

As everyone knows, nobody reads their user agreements when they sign up for apps or services. Even if they did, it wouldn’t matter, because most of them stipulate that they can change at any moment. That moment has come.

You might not be concerned, but I’d like to point out that there’s a reason you’re not. Namely, you haven’t actually seen what this enormous loss of privacy translates into yet.

You see, there’s also a built in lag where we’ve given up our data, and are happily using the corresponding services, but we haven’t yet seen evidence that our data was actually worth something. The lag represents the time it takes for the market in personal data to mature. It also represents the patience that Silicon Valley venture capitalists have or do not have between the time of user acquisition and profit. The less patience they have, the sooner they want to exploit the user data.

The latest news (hat tip Gary Marcus) gives us reason to think that V.C. patience is running dry, and the corresponding market in personal data is maturing. Turns out that EBay and PayPal recently changed their user agreements so that, if you’re a user of either of those services, you will receive marketing calls using any phone number you’ve provided them or that they have “have otherwise obtained.” There is no possibility to opt out, except perhaps to abandon the services. Oh, and they might also call you for surveys or debt collections. Oh, and they claim their intention is to “benefit our relationship.”

Presumably this means they might have bought your phone number from a data warehouse giant like Acxiom, if you didn’t feel like sharing it. Presumably this also means that they will use your shopping history to target the phone calls to be maximally “tailored” for you.

I’m mentally tacking this new fact on the same board as I already have the Verizon/AOL merger, which is all about AOL targeting people with ads based on Verizon’s GPS data, and the recent broohaha over RadioShack’s attempt to sell its user data at auction in order to pay off creditors. That didn’t go through, but it’s still a sign that the personal data market is ripening, and in particular that such datasets are becoming assets as important as land or warehouses.

Given how much venture capitalists like to brag about their return, I think we have reason to worry about the coming wave of “innovative” uses of our personal data. Telemarketing is the tip of the iceberg.


11 Jun 15:37

This is why children should play outdoors

by Minnesotastan

"Hand print on a large TSA plate from my 8 1/2 year old son after playing outside."

Prepared by Tasha Sturm and posted at Microbe World.  Exposure to bacteria and other microbes is an essential element in the development of a healthy human immune system.

Via Neatorama.