Monday, December 27, 2010

Black Swan - Mirror, Mirror

Black Swan movie poster,
courtesy of Fox Searchlight
This essay is taken from a note that I posted on FaceBook about Darren Aronofsky's recent film, Black Swan.  It does not contain spoilers.

The films that I have always found most compelling are those that present an intriguing character, one with whom identification is a difficult, but a rewarding, struggle, and send that character off on a journey of personal discovery. Their appeal, in part, has to do with the fact that the hero's quest for transcendence or, as is often the case, redemption suggests the possibility of our own transformation. They offer us a distorted but beguiling mirror in which the hero's hopes and fears and doubts become our own.

Darren Aonofsky's film, Black Swan, succeeds wonderfully as such a film.

The Aronofsky films I have seen - Pi, The Fountain, The Wrestler and now Swan - invite us to enter personally uncharted territory and there to step into the shoes - or slippers, as the case may be - of, respectively, an unhinged mathematician, a disillusioned conquistador, a dissipated professional wrestler and a psychologically scarred aspiring prima ballerina. It is a testimony to the director's skill and his uncanny selection of players, that we quickly begin to identify with these lost souls, in spite of the fact that their lives and their occupations are entirely foreign to us - an accomplishment all the more remarkable in a movie industry that relies on cookie-cutter characters and characterizations for commercial success.

In each of these works Aronofsky dispatches his reluctant hero on a quest, an attempt both to come to terms with a damaging personal history and to transcend the past by reconciling the demands of art or profession or craft with the reality of the world as it is.

For Swan, this journey of transcendence is rooted in a universal artistic challenge, how to move beyond the technical mastery of a medium and take the risk involved in opening oneself up to messy and often unwelcome psychic forces that are the heart of profound artistic expression.

On one level the film is the story of Nina Sayers (Natalie Portman), a beautiful and talented young ballerina who is poised to become the principal dancer of an unnamed New York company, and must overcome her slavish good-girl commitment to mechanical virtuosity and tap into dangerous emotional currents that emanate from her unexplored sexuality and a toxic relationship with a controlling, ever-watchful mother (played magnificently by Barbara Hershey).

On another level, Swan is a tale of the director's own struggle to put his mastery of the medium of film in service to the telling stories that are not only exquisitely crafted, but also emotionally compelling. Aronofsky's abundant skills are on display as he demonstrates a cinematic range that encompasses both the glossy presentation of lavishly staged ballet as well as the gritty exposition of the intimate details of Nina's personal ordeals. In doing this Aronofsky reminds us that for him the life of genius - and not only artistic genius - is a ongoing flirtation with insanity, a ceaseless effort to locate and occupy the razor's edge that is the wellspring of creativity.

Finally, Swan is a mirror of Natalie Portman's own trajectory as an actor. Poised, as her character Nina is, at a juncture in her career where accomplishment beyond mere technical excellence beckons, Portman has dared to take on a very different role, one that demands that she expose herself, both emotionally and sexually, in order to discover her true potential. This actress is determined to put away childish things - like so many stuffed animals tossed down a trash chute - and declare herself as a performer who can draw on both the light and the dark aspects of her nature.

So Black Swan is all of these, a story about a troubled young ballerina, a story about its director, Aronofsky, and a story about its star, Portman. It is a hall of mirrors, which teases and disorients us by confusing the real world with the imagined. Perhaps most importantly, it is a hall of mirrors in which we are invited - every now and then - to catch a glimpse of ourselves.  In this regard, in a small way, it is also a story about us.

Creative Commons License
Black Swan - Mirror, Mirror by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Tuesday, December 14, 2010

A Conceptual Introduction to the Measurement Problem of Quantum Physics

This is the fourth and last in a series of essays to be used as background for the Atlanta Science Tavern discussion Quantum Physics and Consciousness. It began with this introductory post.

At the heart of the controversy concerning quantum physics and consciousness - raised by the What the Bleep Do We Know!? movie - is a conundrum that goes by the name the measurement problem.  My intention here is to introduce this problem to people not steeped in quantum physics.  I will try to do this while remaining faithful to the concepts that I believe are central to the discussion at hand..

Sextans A, member of the
Local Group
Systems
One of the pervasive concepts in physics is that of a system.  It is an abstraction that is used to refer to something as small as an electron orbiting the nucleus of a hydrogen atom or something as large as our own Milky Way orbiting the gravitational center of the Local Group of more than 30 galaxies.  It can represent something as simple as a pair of photons, particles of light, entangled in a quantum pas de deux, or as complex as a human brain, a wet, warm, messy computational engine, sporting over 1,000 trillion synaptic connections.  Even (Austrian) cats have been recruited in the service of constructing such hypothetical systems.

There is an important assumption regarding a system and that is that it can be regarded as independent or free-standing.  In other words, it is meaningful to discuss a system, at least for limited purposes, as though it exisits in isolation from the rest of the world.  Without this idealization the scientific enterprise as we know it would be doomed, mired in complexity.  Nonetheless, we should keep in mind that it is an approximation.

A gyroscope as a
demonstration of angular
momentum
Properties and States of a System
Ultimately the goal of a physical theory is to offer an accurate description of the behavior of a system over a period of time.  Such a description emphasizes what are considered to be significant properties, features either of the system as a whole or of its constituent parts.

Most notable among these properties of a system (or its parts) are its position and its velocity.  Less concrete, but no less significant, is the property of a system which we call as its energy.  Other properties include mass and electrical charge and quantities having to do with a system's rotational motion, namely its angular momentum or spin.  Modern physics has added a large number of much less familiar properties to this list of quantities used to describe systems.

For our purposes, it is not so much important to know what each of these properties means individually, as it is to understand that they can be used collectively to create a "snapshot" of a system, which defines what is called its state.  One can think of the state of a system as way to designate an enumeration of its properties and their corresponding values at a particular instant in time.

Measurement in General
Measurement can be seen as the process by which the properties, and hence the state, of a system are discovered.  We typically imagine this as involving some sort of measuring device or apparatus, a ruler, a telescope, a radar gun, or a thermometer, for example, but in a very austere sense measurement may involve any kind and any size of physical "probe", used to determine a value for a property of a system.

Measurement in Classical Physics
In classical physics the measurement of the properties of a system, although perhaps technologically challenging, is philosophically straightforward.  A measuring device can, in theory, be refined to obtain an arbitrarily precise value for a property, while at the same time inducing an arbitrarily small amount of disruption to the system as a whole.

Collectively these measured properties, drawn from a continuously-varying range of values, define the state of the system, which is, in principle, indifferent to the effect to the act of measurement.

Bohr atom with
energy levels
Measurement in Quantum Physics - First Twist
Quantum physics adds some unexpected twists to the classical theory of measurement.

For purposes of concreteness, but without loss of generality, we will use the example of a hydrogen atom consisting of a lone electron in orbit around a single proton.

It turns out that when we measure the energy of the orbiting electron we obtain not a continuous range of values, but a discrete set of values, the so-called energy levels of the system.  These fixed amounts, or quanta, of energy - from which the theory derives its name - represent a departure from the classical view of the world in which quantities like energy were assumed to vary continuously

Interestingly enough, and consistent with classical theory, repeated measurements of the energy of the electron yield the very same answer.  Furthermore, measurements of certain "compatible" properties, such as its angular momentum, leave the system undisrupted, and subsequent  measurements of the electron's energy are unaffected.

All hell breaks out, though, when you go to measure something else.

Measurement in Quantum Physics - Second Twist
For example, if you start with a hydrogen atom in a known energy state and measure, say, the position of its electron, then the result of a subsequent measurement of its energy is no longer determined, but may take on any value from the range of allowed energy levels.

In fact the measurement of an "incompatible" property, no matter how carefully made, disrupts the system.  Contrary to classical expectations, the disrupted electron is described as then occupying not one but a multiplicity of energy states, and its amount of "participation" in each of these states determines the probability that the corresponding energy level will be measured the next time around.

Troubling as this is finding may be for measurements of energy, it is even more unsettling to consider that this inevitable mixing of states also applies to measurements of position, the implication being that the electron can find itself, to a greater or lesser degree, at a multiplicity of locations!

DVD cover for Tom
Stoppard's "Rosencrantz
& Guildenstern" Are Dead
Measurement in Quantum Physics - Bottom Line
Unlike measurement in classical physics which can be consigned to a secondary - and diminishing - role, measurement in quantum physics insists on playing a leading one.  The choice of which properties to measure and the order in which these measurements are conducted unavoidably effect the system under observation.

It turns out that the act of measuring specific properties, most significantly energy, places a system in a stable state, referred to as a stationary state or eigenstate, in which values of those properties and compatible ones persist indefinitely.  Intervening measurements of incompatible properties, though, force the system into a configuration that is a mixture of these stationary states, called a superposition.  Although the outcome of individual measurements on a system described by a superposition is unpredictable, their statistical distribution is entirely determined.

A digital multimeter
The Measurement Problem
Since measurement is not a particularly important process in classical physics, it hardly commands a lot of attention.  But in quantum mechanics, measurement is a first class feature of the theory and so this activity has to be much more carefully considered.

First and foremost, what does it mean to say that a measurement has occurred?  Does this happen when a measuring device interacts with the system being investigated?  What distinguishes these "measurement" interactions from other  routine interactions between the system and its environment?

To the extent that the act of measurement is, itself, a causal chain of events described, ultimately, by quantum theory, when, if ever, can we say that it concludes?  Does a measurement end, for example, when photons of light refelected off an LCD display strike the the retina of the experimenter working in her lab?   What if the experimental data is collected autonomously and stored on-line?  Does the measurement finally occur when the data is downloaded and viewed by the experimenter on a remote computer?

Furthermore, what is the detailed mechanism involved in transforming the quantum mechanical superposition of states into a single eigenstate state, which is characterized by the measured value of a property such as energy?  How does this collapse of the wave function (an alternative name for this superposition of states), take place?

Enter Consciousness
These are some of the puzzling questions that have given rise to the variety of interpretations of quantum physics in circulation.  Consciousness enters the picture because some people believe that it may be the critical feature that distinguishes measurement from other physical processes.

So consciousness is, to some extent, reasonably offered as a potential "solution" to the measurement problem of quantum mechanics.  Be that as it may, it is one thing to suggest that consciousness is implicated in the collapse of the wave function, and quite another to insist it is a mechanism that allows us to project our will and desires on the physical world.  This is the leap that the movie What the Bleep takes and this is why its claims are so controversial.

Creative Commons License
A Conceptual Introduction to the Measurement Problem in Quantum Physics by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Sunday, December 5, 2010

Adventures in Quantum Tourism

This is the third in a series of informal posts to be used as background for the Atlanta Science Tavern discussion Quantum Physics and Consciousness.

Cover of Anne Tyler's
"The Accidental Tourist"
Imagine yourself a young person - or an unworldly adult - about to embark on a first-ever trip abroad. You arrive by plane at your destination and are immediately overwhelmed by the strangeness of the place.

For example, the language you hear at the gate sounds less like human speech than like dogs barking. How could anyone understand what's being said?

The signs you see posted as you make your way down the concourse are inscrutable. It's not clear whether the symbols are letters or words, or whether the script is intended to be read right-to-left or top-to-bottom. It all looks so unnecessarily complicated.

Somehow you find your way to a shuttle bus and, as it departs for your hotel, you are alarmed to discover that everyone is driving on the wrong side of the road! Whose crazy idea was this dangerous scheme?

At the hotel, weary from your travel but wanting a bite to eat before you go settle down for a well-deserved nap, you decide to visit the restaurant off the lobby which, mercifully, has photos to accompany the utterly unintelligible text on its menu. Little consolation that, since not one of the items depicted is a dish recognizable to you. To make matters worse, when your meal is served, what appears to be the entrée is unexpectedly sweet and what appears to be the dessert is not sweet at all, but unexpectedly spicy. This is a gratuitously cruel reversal of the correct culinary order of things, as far as you are concerned.

Exhausted from dealing with this onslaught of the unfamiliar, you retire to your room, where, although sleep beckons, you lie awake struggling to come up with explanations for the disconcerting experiences of your day. You are convinced that if only you had the intellectual chops to think long enough and hard enough about the strange things you had seen and heard and read and tasted, then the reasons why they are the way they are would become clear. But struggle as you might, no realization emerges and you finally succumb to sleep, your last thought being, "I'll never understand this place, it makes no sense at all."

The Twice-Told Allegory of the Bewildered Traveler
The above tale is an allegory for the frustration - and sometimes despair - everyone feels when first introduced to the mysterious world of quantum physics. The story continues, of course, taking one of two divergent paths.

In the first variation, the traveler wakes and beats a hasty retreat back to the airport, where she catches the first flight home. There she regales friends, family and colleagues of the bizarre details of her misadventure and the absolute impossibility of living abroad.

With the second telling, the traveler, refreshed by her nap, pauses and then decides to explore a bit before considering whether to cut her trip short. (It seems like the prudent thing to do, since she has come so far.) Fortunately she makes the acquaintance of an expatriate, a fellow from her home country no less, who helps her to understand a useful phrase or two in the local language and to appreciate a couple of tasty offerings of the local cuisine.

Intrigued, she vows to extend her stay, even going so far as to purchase a bicycle which she, with some trepidation, learns to ride on the "wrong" side of the road. Feeling increasingly comfortable in her new environment, she contemplates the possibility of establishing a second home here, and laughs when she reminds herself that she still has no answer as to why this place is so strange, a once pressing question that no longer seems relevant at all.

The Fallacy of Extrapolation
Terra Incognita (BBC Archive)
There's a category of misguided reasoning that goes by the name "the fallacy of extrapolation". Typically it is used to describe the mistake that people make when they assume that a current trend will continue, unchanged, into the future. But it also is a good way to characterize an error that results from imagining that the rules that govern our everyday lives should be the same as those that apply to a novel situation, one for which we have no first-hand experience.

This is exactly the kind of mistake late-19th century physics made when initially confronted with the uncharted territories of the "very fast" (speeds close to that of light) and of the "very small" (distances on the scale of atoms and molecules). And it is the mistake that we all repeat when we are first exposed to the ideas of special relativity or of quantum mechanics, the theories used to describe those two unfamiliar realms.

But, like seasoned travelers, we can benefit from knowing that, if we are open-minded and patient, then the confusion and dissonance that we feel with the first encounter a strange new world will slowly dissipate, and that through acceptance and immersion we can come to enjoy a new home away from home.

Creative Commons License
Adventures in Quantum Tourism by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Saturday, December 4, 2010

Does Anyone Understand Quantum Mechanics?

This is the second in a series of informal posts to be used as background for the Atlanta Science Tavern discussion Quantum Physics and Human Consciousness.

Richard Feynman, Los
Alamos ID badge
Richard Feynman, one of the great physicists of the 20th century, offered this somewhat discouraging claim in his book, The Character of Physical Law, "I think I can safely say that no one understands quantum mechanics."  Given that Feynman was not only a technical but also an intuitive master of the subject - the likes of which will seldom be seen again, I might add - it would be pointless for me to try to contradict him.  But I think it is reasonable to suggest that this oft-quoted statement might benefit from some clarification.

Certainly, as a practical endeavor, many, many thousands of scientists and engineers around the world today understand quantum mechanics.  They use it routinely in their work, whether designing computer circuits or predicting the outcome of the collisions of the protons that hurtle toward each other at near light speed at the intersections of the beam lines of the Large Hadron Collider outside of Geneva, Switzerland.  Indeed, the related theory of Quantum Electrodynamics, of which Feynman was a pioneer, is, hands down, the most successful physical theory ever devised as far as the precision of its predictions is concerned.  It would be hard to beat.

Compact Muon Solenoid at
the LHC at CERN
Yet it comes as a surprise to lay people, who find themselves beguiled by the mystery of quantum physics, to learn only a fraction of physicists are troubled, at least professionally, with the philosophical questions that it raises.  The dictum. "shut up and calculate!" holds sway in laboratories and universities, with the meaning of the theory being no more and no less than its thoroughly demonstrated correctness and utility.

And this is where, to a certain extent, they part company with Feynman, whose discouraging words might more accurately - and perhaps more hopefully - be expressed as, "no one understands yet what quantum mechanics means."  The fact of the matter is that, after almost nine decades of earnest striving, there is no agreed upon interpretation of what quantum physics says about the very nature of the world it so successfully models.  Some have more currency than others, but none has proven so superior that it has vanquished its competitors.

In my opinion it is our failure to formulate a convincing interpretation that fuels the controversy that surrounds the question of quantum physics and consciousness which has motivated the discussion at hand.  The absence of a conclusive answer to the stubborn question of meaning has been an invitation for all contending interpretations of quantum mechanics, of whatever stripe, to enter the fray.

That said, I do think that the central concepts of quantum physics are in fact understandable by "ordinary" people, that is if they are willing to let go of preconceptions and to imagine themselves, instead, as inquisitive travelers to an unexplored country.  This will be the topic of the next post in this series.

Creative Commons License
Does Anyone Understand Quantum Mechanics? by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Thursday, December 2, 2010

Quantum Physics and Consciousness - Why this Discussion?

This is the first in a series of informal posts to be used as background for the Atlanta Science Tavern discussion Quantum Physics and Human Consciousness.

Why this Discussion?
When a handful of science enthusiasts get together to share their thoughts on the "big" questions, the conversation often turns to the mysterious world of quantum physics. Indeed, in a cursory survey of the interests of members of the Science Tavern meetup, the subject ranks near the top of the list of stated science interests.

We are drawn to quantum physics for many reasons, but primarily because it tells us a fascinating and unexpected story, that the world as we experience it is an illusion, and that a deeper reality exists, full of marvels and wonders, accessible to those with the determination to look beyond mere appearance.

The Cave: An Adaption of
Plato's ;Allegory in Clay
In this regard quantum physics arrives as a concrete realization of Plato's Allegory of the Cave and the alluring prospect that knowledge can truly set us free. It also represents the last best hope for the existence of any kind of magic, a possibility that had been all but banished from consideration by the thoroughly deterministic program of classical physics that began with Newton and reached its apogee at the end of the 19th century. Likewise, the overthrow of determinism by quantum physics offers hope to some for a theory of free will compatible with our scientific understanding of the world.

"What the Bleep" movie
poster
It is not surprising that these intriguing ideas have found there way into popular culture. The treatment that motivated the discussion at hand is a movie from 2004, What the Bleep Do We Know?, which sparked a brief, but heated exchange, on our meetup website recently. As a result of the way it interprets the relationship between quantum mechanics and human consciousness, the film has become both a manifesto for adherents of so-called quantum mysticism and a target for derision by the scientific community at large.

Our purpose is to probe the origins of this controversy and to try to come to a common understanding about the physics that is at its core.

Two Questions in One
I should note in closing this introduction that the question of quantum physics and consciousness - I will refrain from using the somewhat parochial qualification "human" consciousness from here on - divides itself, not so neatly, into two.

The first has to do with metaphysics - in the strict sense of that word. Does a comprehensive theory of physics require consciousness as a fundamental feature? This is the quandary at the center of the What the Bleep dispute.

The second question has to do with the origin of consciousness and the role that quantum physics plays in the emergence of it as a physical phenomenon. In this case the question, on its face, is not so controversial; brains, at least from a materialistic perspective, are physical entities describable, ultimately, in quantum mechanical terms. There is, though, much active discussion and disagreement about the variety of schemes that have been proposed as possible answers.

The two questions are not entirely independent, but for the time being, I will focus on the first as this series continues.

Creative Commons License
Quantum Physics and Consciousness - Why this Discussion? by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Monday, September 20, 2010

The Wealth of Hominids - Matt Ridley's "The Rational Optimist"

This is the first of several essays inspired by Matt Ridley's new book, The Rational Optimist.

Every so often a book comes along that punctuates the relative equilibrium of my understanding of the theory of evolution, dramatically altering my appreciation of the processes by which life on this planet has changed over time.

In 1976 Richard Dawkins' The Selfish Gene, with its startling premise that the gene, and not the individual organism, was the fundamental unit of natural selection, made me aware that Darwin's then more than century-old theory was not gathering dust, but was being actively refined, and its details even debated.

About the same time E. O. Wilson's Sociobiology appeared, assuring me that knowledge of biology can indeed inform our understanding of the behavior of animals, including ourselves, all in the face of a bitter opposition, which, to this day, mistakenly conflates Wilson's scientific description of biological tendencies with political prescription for biological determinism.

In 1981 with Lucy, Donald Johanson introduced me to the nuts and bolts of the practice of paleoanthropology and helped me realize that the study of human origins involves not only the reconstruction of the skeletons of our ancient ancestors and cousins, but also the reconstruction of their lives.

And of course there are the books by Stephen Jay Gould, too numerous to mention, many collections of his essays for Natural History magazine, in which he disabused me of the received wisdom concerning the pace and direction of evolution and replaced it with stories of accident and contingency, calling my attention to the modest evolutionary spandrels nestled between the showy arches that, together, constitute the cathedral of this wonderful life.

More recently, Daniel Dennett in Darwin's Dangerous Idea opened my eyes to the fact that the central thesis of Darwin's On the Origin of Species - that is that remarkably complex systems could evolve from simple beginnings, without direction, according only to the dictates of selective forces - operates beyond the domain of biology and that, because of its universal applicability, occupies a singular position in our intellectual firmament.

I now count Matt Ridley's The Rational Optimist in this list of important influences.

The War Room, a documentary
of the 1992 Clinton campaign
Optimist opens with a bold proposal, an assault on a persistent question about our beginnings, that is, what exactly was it, a little more than 100,000 years ago, give or take, that stirred us - even by then long fully-formed humans beings - from eons of technological lassitude and launched us onto a trajectory of ever-increasing material prosperity?

Ridley's answer, always acknowledging a debt to his hero Adam Smith, could well be expressed as a variation on that watchword of the 1992 Clinton presidential campaign, "it's the economics, stupid."

A startling, and unexpected, implication of his thesis is that our humanity, contrary to conventional thinking, is not a legacy bequeathed to us, something that we possess unconditionally, but a dynamic process, one for which we are specifically suited, a glorious dance, but one which lasts only so long as the music plays, and that music, according to Ridley, is the activity of barter and exchange.

Creatures that we would recognize as modern humans have been around for some time, the better part of 200,000 years.  Not only do we share the same basic body plan and, from all indications, cognitive capabilities with these predecessors, but so did they with their own hominid contemporaries, the unfairly maligned Neanderthals, who, if cranial capacity is any indication, may have been a tad smarter.

Obsidian handaxe from the
Ethiopian Acheulean period
(courtesy of Melka Kunture
Museum)
Speech is unlikely to have distinguished these first cousins from one another; genetic analysis indicates that both species possessed a variant of the FOXP2 gene, which is an established marker for that facility.  Indeed, their common ancestor, homo heidelbergensis, dating back half a million years or more was likely to have been a talker, too.  And speech is not all that they had in common with heidelbergensis.  The archeological record demonstrates that both predecessor and successor species, separated by tens of thousands of generations, employed, with minor modifications, the same set of tools.  In particular, the centerpiece of their technology, the Acheulean handaxe, itself, had remained largely unchanged for hundreds of thousands of years.

Why then, after a near eternity of tiresome technological sameness, does a new, expanded and far more capable toolkit appear and begin to become established 100,000 years ago?

Was it some dramatic change in climate that triggered this great leap forward?  According to Ridley, likely not;  such climatic swings occurred in preceding geological epochs and, yet, there is no indication that they prompted advances in human intelligence or, for that matter, that they should have.  Perhaps a propitious genetic mutation was responsible?  As the author points out, though, the evidence for new tools appears erratically, distributed both in space and in time, a pattern hardly consistent with the diffusion of a favorable trait from a single point of origin. And, once these innovations take hold, they point toward a process of escalating technological progress whose rate, nonetheless, varies from place to place, a phenomenon not indicative of an "intrinsic" new human capability.

Instead, Ridley proposes that, having been equipped with a knack for specialization, itself an artifact of our inculcated roles as hunters and gatherers - a division of labor that, it appears, Neanderthals did not practice - and having reached sufficient population densities so that contact with neighboring groups became commonplace, these early modern humans began to exploit such encounters as opportunities to offer things that they were relatively adept at creating or acquiring in exchange for things, which if they had produced themselves, would have distracted them from making the best use of their skills and available resources.  This kind of varied, asymmetric give-and-take, quite different from the acts of reciprocity that had likely been a characteristic of primate behavior for tens of millions of years, was something new to the world.

David Ricardo
(1772 - 1823)
But the magic here, if it can be called that, is not simply the appearance of barter on the human scene, but the fact that such trade itself encouraged further specialization, and that, in turn, encouraged more trade.  The invisible hand at work is not so much Adam Smith's market, as it is David Ricardo's law of comparative advantage, the seemingly counter-intuitive notion that, in many circumstances, we are better off paying more for goods that we could have made ourselves, if by doing so we gain time and resources otherwise spent to do what we do best, that is, make those things that we make most efficiently.  I say "seemingly counter-intuitive" because, although this abstract law of economics was not explicitly formulated until 1817, it appears to have been implicitly grasped by our forbears as early as the late Pleistocene.

So, with trade promoting more specialization and specialization, by making more goods available at lower cost, promoting more trade, a self-catalyzing cycle leading to open-ended material progress was underway, and the rest, as they say, is history, our history, a history that Ridley details in much of the remainder of his book.

Speculative theories about human origins are, of course, a dime a dozen.  The requirement that they conform to the available evidence certainly reduces the number of contenders.  But how, then, do we go about further winnowing?  Ordinarily, in order to reconcile competing conventional scientific claims, we turn to laboratory experiments, an approach that is not typically available to historical sciences such as evolutionary biology.  Interestingly enough, what sets Ridley's approach apart is that he succeeds in proposing two experimental tests for his theory, one that, it turns out, nature conducted on our behalf 10,000 years ago and another that is within our investigative reach today.

If barter is central to human progress, as Ridley suggests, then a human population once isolated should, at best, stagnate technologically.  Indeed, if forces are at work that deplete its reserves of expertise, such a population, cut off from exchange, might well be expected to regress.

Landsat photo of the
island of Tasmania
The stage was set for Ridley's historical experiment some 35,000 years ago, when human beings first arrived on the island "laboratory" of Tasmania, then still joined to the mainland of Australia by a land bridge.  With them they brought knowledge of how to fashion a variety of things, everything from fish hooks to canoes, samples of the inventory in use in the regions from which they came.  Around 25,000 years later, as the glaciers of that ice age receded and the oceans filled once again, these aboriginal pioneers were cut off from interaction with the outside world.  By the time Europeans reestablished contact in the 17th century, the 5,000 or so hunter-gatherers of Tasmania had reverted to a much more limited set of tools and a much simpler way of life.  Apparently, left to their own devices, so to speak, and deprived of not only the progressive, but also the rejuvenating influences of trade, the Tasmanians entered a decline which ultimately erased much of tens of thousands of years of prior technological advance, just as the author's theory predicts.

Space-filling model
of oxytocin
As a contemporary test of his thesis, Ridley proposes our taking a closer look at the genetics of the oxytocin system in humans.  This neurotransmitter, sometimes called the "cuddle hormone", present in all mammals, is implicated in the regulation of a variety of behaviors, in particular those having to do with female reproduction and infant care.  Recent studies in human subjects, which Ridley cites, indicate that, in addition, oxytocin facilitates a tendency to take social risks, most significantly for his purposes, the extension of trust to strangers.

For exchange to gain a foothold there had to be, at a minimum, a suspension of the hostilities that erupted as a matter of course when bands of unrelated primates, including early humans, encountered one another.  Ridley speculates that, in some sense, there was just the right kind of oxytocin, trust juice, as he calls it, flowing in the veins of our ancestors - and activating appropriately tuned receptors in their brains - to make a critical amount of social risk taking possible.

Once even a marginal inclination to barter with strangers was in place, though, it would have offered such advantages, that selective pressures favoring an even more robust "trust response" would have come into play, modifying the physiological mechanisms in humans by which oxytocin is produced and processed.  If Ridley is right, we carry the biochemical markers for these behaviors with us today, and a targeted analysis of our genome should reveal a timeline for their appearance, a chronology that should be consistent with significant modifications beginning around 100,000 years ago.

It should be noted that by proposing this experiment, Ridley not only offers a test that could substantiate his hypothesis, but also one that could potentially undermine it.  In a world replete with just-so stories masquerading as evolutionary biology, it is refreshing to have a theory to consider that flirts with falsifiability, a criterion that serves to differentiate serious science from plausible conjecture.

Frescoes of dolphins from
bronze age excavations
on the island of Crete
Although Rational Optimist does not directly address the age-old question of human uniqueness - that is, what feature of our biology or of our behavior sets up apart qualitatively, not only from our hominid ancestors, but also from extant species, most notably dolphins and other great apes - much of what Ridley has to say about the critical importance of social risk taking, as evidenced by the extension of trust to unrelated individuals, in the origin of barter and exchange would seem to have significant bearing on that issue.

Of course, the question of human exceptionalism is, itself, problematic; perhaps it is simply the case that we differ from other animals in a large number of small ways, something that, in fact, could be said about the standing of most any creature on this planet; and, understandably, it is difficult, if not impossible, to see beyond our anthropocentric biases in forming an "objective" determination about whether we occupy a special status in the biological world.

Whac-a-mole arcade game
(courtesy of Sakura)
Nonetheless, attempts to answer this provocative question have proven to be instructive, if not conclusive, with the call-and-response argument coming to resemble a version of the Whac-a-mole arcade game.  In this variation the moles are candidate distinguishing human traits (e.g. bipedalism, pair-bonding, tool use, brain size, culture, language, symbolic thinking or empathy).  In the course of play each contender pops its head out of its hole, hoping to dodge the ever-looming mallet of contemporary or ancestral counterexample.  Suffice it to say, historically, moles have not fared well in this competition, although one would have to concede that some do battle on, battered but unbowed.

Sylvio Tuepke / New York Times
To the extent that there is a "last mole standing" in the aftermath all this whacking, that title might go to the characteristically human activity recognized broadly as "cooperation".  As noted above for barter, complex collaboration, much richer than simple in-kind reciprocity, is well outside the the prosocial repertoire practiced by other primates.  Indeed, the simple act of sharing food with strangers, a behavior that emerges, apparently without training, in human infants, and one wonderfully documented in Michael Tomasello's book, Why We Cooperate, finds no correspondent among our great ape brethren.  It is, at a minimum, intriguing that this cooperative disposition of ours, in some sense an urge to help, which sets us apart us from other living species, also closely resembles the willingness to extend trust to strangers that Ridley proposes was instrumental in enabling the process of exchange that set us apart from our hominid ancestors.

Going out on a limb a bit, I might argue that Ridley's insight points us toward a different sort of resolution to the question of human exceptionalism.  Perhaps it is the case that, on one hand, deprived of the opportunity to engage in exchange with outsiders, human groups - to borrow a phrase used by Darwin in Origin - revert to a state of nature, a condition in which they are much like a proverbial third chimpanzee, an admittedly interesting, but unexceptional, bipedal primate.  Yet, on the other hand, it could be that, when the distribution of human bands makes routine contact possible over an extended period of time, the full potential of our facility for cooperation is realized and, we, as a result, do attain a stature that is unique in the animal kingdom.

Lasius niger - black garden ant
(courtesy of
Jens Buurgaard Nielsen)
From this perspective, our oxytocin-fueled inclination toward taking social risks can be seen as a genetic trait, but, in the sense of Richard Dawkins' extended phenotype, one that only finds meaningful expression when the geographical arrangement of human populations conforms to a critical configuration that allows barter to take hold.  E. O Wilson has observed that individual ants, in some sense, don't exist outside the context of the colony to which they belong.  Perhaps an analogous claim could be made for human beings, not so much that they don't exist outside of systems that support barter and exchange, but that, when they are isolated from such, their humanity is not fully expressed.

I'll close by noting that this line of thinking is not without practical, although not immediate, consequence.  Since the dawn of the atomic age and, with it, the prospect of "assured destruction", followed in short order by our first tentative steps toward becoming a space-faring people, much has been made of the proposition that, in order to insure our survival as a species, we must dispatch some brave souls from among our ranks to self-contained orbiting cities or to settlements on nearby, or even distant, planets.  More recently, the possibility of environmental collapse or asteroid impact has increased the sense of urgency that surrounds these proposed missions, with no less a great thinker than Stephen Hawking - the go-to commentator on all matters existential these days - recommending that it's time for us to start preparing "to go to a another star".

Artist impression of a Mars
colony with a cutaway view
I, for one, hope that the planners of these noble ventures keep Matt Ridley's hypothesis in mind when they go to their drawing boards, in particular, that they think carefully about how to maintain an exchange of ideas, if not goods, between far-flung human communities or devise some sort of technological or sociological fix to make up for its absence.  It is sad to contemplate that we might indeed survive as a species, but not as the species we are, that any extraterrestrial colony, bereft of the progressive and rejuvenating influences of trade, in the broadest sense of that word, might as well be christened "New Tasmania".

I would like to thank my friend Bill Shropshire for many stimulating discussions that went into helping me prepare this essay.


Creative Commons License
The Wealth of Hominids - Matt Ridley's "The Rational Optimist" by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Sunday, July 25, 2010

Dinesh D'Souza, in the Dark about Dark Matter and about Science

Of all the attacks leveled against science by the religious faithful, the most insidious are the ones that cast religion and science as comparable approaches to understanding natural the world.  In a debate with Christopher Hitchens at Notre Dame this past January conservative author and speaker Dinesh D'Souza showcased a variation of this kind of "we're just two peas in a pod" claim and, in doing so, succeeded in demonstrating a genuine failure to understand how science really works.  In the process, he does no great service to religion, either.

In making his case for a faith-based approach to science, D'Souza proposes that the existence of God can be employed as a working hypothesis much like any other.  And, as with any provisional hypothesis, he says it should be embraced when it helps account for phenomena which have otherwise resisted explantion.  Seeking confirmation of this God of the gaps argument - familiar to us from the Intelligent Design controversy - D'Souza turns to astrophysics for an illustration of how science relies on the same kind of speculative thinking that religion does.  Here is the background on the example he finds there to exploit.

Galaxy cluster ACO 3341, located
almost 500 million years away
(European Southern Observatory)
The Mystery of the Missing Mass
In the 1920s, not long after galaxies outside our own Milky Way were first identified, they were seen to arrange themselves into clusters, orbiting about one another, presumably, under the influence of their mutual gravitational attraction.  Indeed, the working of gravity in these far, far away places was not unexpected.  Contrary to popular conception, Isaac Newton's stroke of genius had not been in observing a falling apple - he was hardly the first to notice that things fall - but in his bold conjecture that the force responsible for causing his proverbial knock on the head was the very same force responsible for the motion of the planets about the Sun.  Newton's theory proposed that gravity was universal, applying uniformly to everything, everywhere; to the objects of our everyday experience; to the planets and moons of our solar system; and, presumably, to galaxies, each consisting of hundreds of billions of stars, located millions of light-years away.

What took astronomers of the 1930s by surprise was that, when the amount of stuff in these galactic clusters was finally tallied, gravitational accounts did not balance.  A census of the visible matter contained within them - stars and dust clouds and other such "luminous" things - resulted in a total mass insufficient to bind them in their mutual orbits.  According to calculations the galaxies in these clusters should be flying apart at breakneck speed.  The physicists faced a quandary: either Newton had got it wrong, and the force of gravity he proposed was, in fact, not universal, or their exhaustive attempts to catalog the constituents of these galactic clusters had left a significant amount of matter unaccounted for.

Bullet Cluster, best evidence
to date for the existence of
dark matter.
At first this astrophysical mystery went by the name "missing mass" and it was presumed to be an artifact of limitations of the observational techniques available at the time.  Perhaps, for example, large numbers of dead or dormant stars had gone unobserved and, therefore, uncounted in the celestial tally.  But even when astronomers refined their efforts at detection, their gravitational bookkeeping kept coming up short.  To make matters worse, after a few decades passed, new astrophysical puzzles were encountered that also hinted at the existence of missing matter in other astrophysical contexts.  Finally, and reluctantly, a working hypothesis came to be accepted.  The vexing missing mass was assumed to be bound up in a heretofore undetected kind of "dark matter" which was characterized solely by its heft and its failure to shine. Of what it was actually composed, no one had a clue.

Next generation detector,
Xenon Dark Matter Project
Desperately Seeking Dark Matter
Now, according to D'Souza, in the same way that physicists have proposed the existence of dark matter as an explanation for an enigmatic phenomenon, the stability of galactic clusters in spite of an apparent insufficiency of mass, so too can we rely on the hypothesis of God to explain other mysteries of the physical world.  He contends that such "presuppositions" are valid elements in the construction of scientific theories because they yield immense explanatory payoff; disconnected pieces of a puzzle fall into place and suddenly everything makes sense.

Is D'Souza right?  Are "materialist" scientists and those who defer to faith-based hypotheses playing by the same rules?  To see how the their approaches differ, consider this observation from a recent physics arXiv blog post - First Evidence That Mirror Matter May Fill the Universe? - regarding ongoing efforts to solve this problem.
Astronomers call this hidden mass 'dark matter' and physicists around the world are engaged in an increasingly desperate race to find evidence of it here on Earth. [emphasis added]
Now imagine, for a moment, an analogous report on the state of current investigations into some phenomenon or other "explained" by D'Souza's God presupposition:
Scientists call this hidden cause 'God' and researchers around the world are engaged in an increasingly desperate race to confirm His existence.
This comparison, of course, strikes us as ridiculous on its face; no one has ever embarked upon a search for God in order to confirm or refute a physical theory.  Good Lord, how could such a search even be conducted?  Perhaps more significantly, no teams of researchers have ever engaged in a desperate race to reveal God's existence.

What D'Souza fails to appreciate in his casting dark matter as just another presupposition is how unpalatable resorting to such a hypothesis is to physicists, one which they entertain reluctantly because the alternative, a rejection of Newton's theory of universal gravitation, would be even more distasteful.  They tolerate "dark matter" as a convenient fiction, but won't rest easy until the composition of this mysterious substance is revealed, or until a more acceptable explanation steps up to replace it.

History confirms how earnest physicists have been in wrestling similar "presuppositions" to the mat.  Interestingly enough, three examples involve a search for missing mass of one variety or another.

Neptune from the Voyager 2
flyby (1989).
A Missing Planet Found
The first hidden matter search came about with the discovery of Uranus by Sir William Herschel in 1781.  With Newton's theory in hand, astronomers were able to calculate the orbit of the newly discovered planet, but by the early 19th century it had become clear that discrepancies existed between the predicted trajectory of Uranus and that which had been meticulously observed.  These scientists were presented with a dilemma not unlike the one that their counterparts would face a century later: either Sir Isaac had gotten things wrong with his theory of gravity or a very significant mass had gone missing.  Perhaps it took the form of a yet undetected outlying planet which was perturbing the motion of Uranus in its path around the Sun?

As disagreement between theoretical calculations and observational evidence became more and more convincing, a desperate race ensued.  The hidden culprit, the planet Neptune, was revealed by Urbain LeVerrier in 1846.

First neutrino detection
in a bubble chamber (1970).
A Missing Particle Detected
In a second example of a missing mass mystery, by 1930 the radioactive decay of atomic nuclei into constituents components had been long-observed and carefully measured, yet, as a result, a vexing question arose.  When the energies of all the particles emerging from the site of such a decay were added up there was an unexpected energy shortfall.  Either a new kind of particle had fled the scene undetected, carrying with it just the right amount of energy (and, according to Einstein, mass) or the long-cherished principle of conservation of energy - far more fundamental for physics than even Newton's universal gravitation - would have to be abandoned.

This fugitive particle, dubbed the neutrino by Enrico Fermi in 1934, eluded capture for more than two decades; science did not breathe a sigh of relief until Clyde Cowan and Frederick Reines detected it directly in 1956.

Schematic of Earth moving
through the hypothetical aether.
The Aether goes Missing - with a Payoff
As a final example of the search for a missing substance - and an illustration that presuppositions demand verification - consider the state of the physics of electromagnetic radiation - i.e. light - in the late 19th century.  About the time of the American Civil War James Clerk Maxwell, in what has become to be regarded as the first unified field theory of physics, demonstrated mathematically that light traveled as a wave, not unlike the way waves spread across the surface of a body of a water.  In much the same way that other wave phenomena required a supporting medium - for example, some gas or mixture of gases for sound - it was presupposed that a medium was necessary for the propagation of light, something that pervaded every nook and cranny of space.  Confident in this hypothesis, physicists even gave the conjectured substance a name; it was called the luminiferous (light-bearing) aether.

An ingenious experiment to detect the existence of this mysterious stuff was undertaken by Albert Michelson and Edward Morley in 1887.  It failed utterly, but with that failure was planted the seed of Einstein's theory of special relativity which would blossom less than 20 years later.

As these examples illustrate, what Dinesh D'Souza does not understand is that for scientists a presupposition, better characterized as a working hypothesis, is not the end of an investigation, but a starting point.  Presupposing the existence of God as an explanation, as D'Souza suggests, offers no avenue for further research, it is nothing more than prescription for investigative complacency;  one might as well hang a "gone fishin'" sign on the laboratory door.  Regardless of the spiritual rewards that some derive from a belief in God, as a scientific hypothesis it is worse than a blind alley; positing God as an explanation discourages further research, sometimes benignly, by declaring, falsely, that a difficult problem has been solved, and at other times malignly, by intimidating those who dare to seek honest answers based in physical law.

It is important to point out that D'Souza's attempt to exploit the dark matter hypothesis as evidence of the comparability of scientific and religious reasoning about the world is just the latest round in the assault on science by those who, like him, feel that a purely materialist view of nature is incompatible with their deeply held religious beliefs.  In the late 1980s they took aim at the theory of evolution with their Intelligent Design hypothesis and were, in short order, discredited.  Probing for vulnerabilities elsewhere they have recently turned their sights on astrophysics and neuroscience, hoping for more favorable battlefields.

But, as Ken Miller, professor of biology at Brown University and a practicing Roman Catholic, noted in his essay, The Flagellum Unspun, which convincingly refutes claims of "irreducible complexity", the cornerstone of Intelligent Design theory,
... the struggles of the intelligent design movement are best understood as clamorous and disappointing double failures – rejected by science because they do not fit the facts, and having failed religion because they think too little of God.
Sadly, Dinesh D'Souza seems compelled to repeat this same mistake, looking for confirmation of his belief in God in the wrong places, misrepresenting the enterprise of science and futilely struggling to insert the Deity in the forever-narrowing gaps in our understanding of the natural world.

Creative Commons License
Dinesh D'Souza, in the Dark about Dark Matter and about Science by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Wednesday, June 16, 2010

Splice the Movie - Paradise Fail

This is my take on some of the ideas touched upon in the recently released science-fiction movie, Splice. Do not mistake it for a review. It does contain spoilers.

"Just imagine what we could learn!"  With this seductive, and in some ways desperate, plea Elsa Kast (Sarah Polley) implores her partner in love and in science and, potentially, in crime, Clive Nicoli (Adrien Brody), to join her in the tasting of the tree of the knowledge of trans-human possibility.  Even as the plot of Splice is sparked to life by this Faustian offer, it is already clear that this prideful duo of rock-star genetic engineers is heading for a most certain fall.

So, in some respects, Vincenzo Natali's serviceable sci-fi / horror flick is a variation of the story of The Exile from Eden, with a Generation X Eve and Adam arrogating the power of God to themselves, tampering with the primal forces of nature and discovering in the process that the knowledge of good and evil tends to be almost exclusively about the latter.  Paradise fail, to use the vernacular.

Splice works also as an allegory of sorts for the trials of contemporary parenting: the agonizing over whether to have children and, once they appear, how to fit them into demanding professional lives; the hard-to-dispel worry that the sins of our fathers, and of our mothers, as painfully recognized in the flaws in our own upbringing, will be visited upon our own sons and daughters; and that we, heaven forfend, will "become" our own parents and thus be compelled to repeat the mistakes they made with us.

To make matters worse, there is the additional burden peculiar to the current crop of moms and dads, that is that children not only be reared, but also, in some sense, perfected; that parents are duty-bound to orchestrate the development of their progeny, even in utero, so that they may emerge as Baby Einsteins.  Little do Elsa and Clive realize that all their prenatal fretting and fussing will result in something more akin to Baby Frank-einstein.

Which brings us to the main storyline of Splice, an updating of the Mary Shelly gothic-horror, proto-science-fiction classic.  It is interesting to recall that Shelley's Frankenstein was subtitled "The Modern Prometheus".  Its protagonist, Victor Frankenstein, had not set out to create a monster, but to benefit humanity by conquering death.  Elsa and Clive, our post-modern Prometheans, somewhat less ambitiously, have set their sights on the conquest of disease - diabetes, Parkinson's, Alzheimer's and the like - yet they nonetheless reap the unintended - and unwanted - consequences that are payback for their act of hubris.

The morally questionable experiments central to both the novel and the film are quite similar, new life is assembled out of inanimate biological bits and pieces.  Shelley's homo novus is cobbled together from freshly-exhumed human body parts; in Splice it is the strands of DNA from disparate species that are woven to craft a new being, with human genes, bearing the taint of the propensity for predation as well as, it appears, that of original sin, tossed into the mix.  Unlike Victor Frankenstein, though, who is thoroughly disgusted by his creation and abandons it in remorse, Elsa and Clive respond with a confused mixture of caring and revulsion, uncertain as the story progresses whether to nurture or to kill their new child.

Splice adds a new twist to the complicated relationship between the scientists and their creature, and that is the - sometimes mutual - feeling of sexual desire.  It's not clear what writer-director Natali intends by this unexpected turn, which is disturbing more because of its implications of pedophilia and incest than the violation of a taboo having to do with inter-species love. Perhaps it represents the ultimate table-turning comeuppance for its "parents", Elsa and Clive, in a concrete "who's your daddy?" demonstration of dominance by their genetically misbegotten offspring.   Or maybe it is the pretext for a Splice sequel, as suggested by a Rosemary's Baby moment at the end of the movie.  It looks like we'll have to wait and see.

Creative Commons License
Splice the Movie - Paradise Fail by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Friday, March 5, 2010

"Crazy Heart" - Just Duet

This is a reposting of my short Facebook note on Crazy Heart.  It does contain spoilers.

In a milestone role to rival his iconic turn in The Big LebowskiJeff Bridges gives us in Crazy Heart the character Bad Blake.

Bad, a 57-year-old country-music singer-songwriter in the process of personal and professional self-destruction, believes that a long-sought duet with sideman, now rival, Tommy Sweet (Colin Farrell) is what he needs to resuscitate his more than moribund career.  Little does Bad realize that his true redemption lies within the constellation of other duets that define his life.

- There is the well-rehearsed, bickering call-and-response standard that pampered-star Bad belts out with his long-time manager, like the profane, but choreographed, squabbling of an old married couple, which hardly conceals the affection that has bound them together over the course of decades.

- There are the tawdry pas de deux that lothario Bad performs with his adoring female fans, middle-aged woman who seek him as a last opportunity to taste the passion that the everyday world has denied them, as he seeks in them refuge from the pain and loneliness of his life on the road.

- There is the reassuring ballad of friendship that wayward Bad shares with Wayne (Robert Duvall), a steadfast beacon in his storm-tossed life, who stands ever ready to guide him home and, ultimately, to safe harbor.

- There is the ancient song of invocation that poet Bad sings to beckon his muse, Jane (Maggie Gyllenhaal), a beautiful younger woman who stirs the creativity buried within his misery, and then, as muses must, returns to the realm of his dreams.

- There is the lullaby that erstwhile daddy Bad coos lovingly to Jane's 4-year-old son, Buddy, a moment of grace that allows him to imagine, if only briefly, the possibility of second chance at fatherhood, his first having been squandered in the recklessness of his youth.

- And then there is the true father-son duet which Bad eventually does perform with his one-time apprentice Tommy, a hard-fought lesson that genuine success for Bad has to do with finally learning how to yield center stage and share the spotlight.

What Jeff Bridges and director Scott Cooper have done In Crazy Heart is to orchestrate this chorus of pair-wise songs - each moving in its own way - to create the compelling and memorable character of Bad Blake, and, in doing so, they remind us, how each of our lives is composed, fundamentally, of a similar arrangement of intimate duets.


Creative Commons License
"Crazy Heart" - Just Duet by Marc Merlin is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
Based on a work at thoughtsarise.blogspot.com.