Moral Compass

Whoever coined the phrase "moral compass" got it right. Compasses align themselves with the magnetic field of the Earth and, under normal circumstances, point toward the North Pole. But when placed near a magnet, a compass realigns itself to account for the presence of a new magnetic field.

Morality turns out to act exactly the same way. Most of us share some general principles of right and wrong; we seem to have a moral instinct analogous to a compass's sense of North. But applying a magnetic field to a person's brain can seriously realign his or her moral compass. Watch this TED video:

Butterfly Wings: The Bee's Knees

During a jaunt through Florence's Natural History Museum this morning, I spent a long time gazing at its 18th-century collection of butterflies. While many other creatures displayed in the museum looked ancient and faded, the butterfly specimens were just as brilliantly blue, white, neon green, and multi-colored as if they'd been netted and pinned up yesterday.

Why should this be the case? It turns out that many butterfly wings aren't colored with pigments which break down or brush off over time; rather the colors arise from the nano-scale structure of the wings themselves.

If you zoomed in on the surface of such a wing, you would see a forest of identical structures a few hundred nanometers tall and apart. These strange structures, made of chitin like the rest of the wings, are spaced regularly across the surface in a periodic array. When light strikes them, the size, shape, and spacing of these structures determines which wavelengths get scattered, and which are allowed to propagate along the surface. The color of the propagating light is what you see.

Physicists and engineers have been trying to construct 3-D photonic crystals - periodic structures which control the flow of light - for the past few decades. To affect light in the visible range, their crystals must have features with sizes on the order of visible wavelengths: namely, several hundred nanometers. Features that are much bigger or much smaller than the wavelengths of light aren't "felt" by it. Light gets bent and diffracted by objects on its own scale, but engineering arrays of such small objects has been exceedingly difficult for humans.

Not so for nature. Butterflies display a huge range of colors and patterns, all coming from different shapes and arrangements of their nano-scale structures. For example, bright green originates from an array of spiraling gyroids. The gyroid shape is known to mathematicians because it has the minimum possible surface area for a certain set of boundary conditions. And it appears by the million, in impossibly miniature form, on the wings of butterflies who know nothing about boundary conditions.

Engineers at Yale have recently started using butterfly wings as templates for modeling their own photonic crystals. I used to work in a nonlinear optics lab myself. Our interest was in light manipulation, mainly using photonic crystal fibers. My research advisor kept a Morpho butterfly wing in a petri dish on his desk for inspiration.

Too Random Number

When asked to pick a number between 1 and 20, a preponderance of people pick the number 17. This is no mere spider-eating hearsay: the effect has been demonstrated over and over again, and discussed by such wry skeptics as Sean Carroll and PZ Myers. Humans are inexplicably inclined toward that particular number.

The best explanation is that 17 seems really random. Being prime, it isn't part of any simple arithmetic or geometric progression. And unlike the numbers 3, 7, and 13, it doesn't have any obvious cultural significance. Though the preceding arguments don't explain why 17 beats out 5, 11, or 19, it must be an attempt to seem unbiased and arbitrary that leads us to choose 17 from among a given range with thrice the statistical likelihood. What strikes us as the most random number is thereby made the least so.

Humans have such an affinity for patterns that we can't help including them when trying to generate random information - or overly excluding them as in this case. We are hopelessly non-random, and so since ancient times we've had to employ devices like dices, coin flips, and more recently, computers, to achieve random results for us.

Imagine for a second how different things would be if we possessed the ability to be random. At the beginning of an (American) football game for example, no coin would need be tossed to determine the receiving team; the ref would just shut his eyes for a moment, concentrate, rid himself of bias, and choose between the teams with complete fairness.

That is unimaginable. Our inability to be random - our inherent possession of preference - is part of what makes us human. But why such a preference for 17?

Fractured Skulls in Fractal Decline

In response to the post about dog domestication, a couple of readers wondered if lower adrenaline levels would make humans less aggressive. In fact, whether or not the phenomenon is adrenaline-related (and it probably isn't), we are becoming markedly milder-mannered as time goes on.

"In the decade of Darfur and Iraq," writes Steven Pinker, "and shortly after the century of Stalin, Hitler, and Mao, the claim that violence has been diminishing may seem somewhere between hallucinatory and obscene. Yet recent studies that seek to quantify the historical ebb and flow of violence point to exactly that conclusion."

World Map of Violent Death Rates (2004)

The decline of violence, he says, is a fractal phenomenon. There are ups and downs, but the proportion of humans meeting violent ends is decreasing overall on every scale. On the millennial scale, anthropologists determine this by looking at the percentage of prehistoric skeletons found with axe wounds and the like, and at the number of violent fatalities in contemporary hunter-gatherer tribes. If proportions of violent deaths now were the same as in the ancient past, they estimate that 20th century warfare would have wiped out 2 billion people rather than the 100 million who were killed. The difference is vast.

There is century-scale improvement also. Europeans used to be incredibly brutal. 14th century statistics establish the homicide rate in England as 24 per 100,000 people, whereas the rate was 0.6 per 100,000 in the 1960s.

Pain and violence was a part of daily life. For example, in A Distant Mirror, a history of the 14th century, Barbara Tuchman describes a favorite European pastime: "In village games, players with hands tied behind them competed to kill a cat nailed to a post by battering it to death with their heads, at the risk of cheeks ripped open or eyes scratched out by the frantic animal's claws. Trumpets enhanced the excitement." She goes on to note: "Accustomed in their own lives to physical hardship and injury, medieval men and women were not necessarily repelled by the spectacle of pain, but rather enjoyed it."

Deaths in interstate conflicts show a huge decline over the past several decades as well, and even on the scale of the past several years. Read Pinker's article in The New Republic for the evidence.

Constant media coverage of war and violent crime makes it hard to believe it could possibly be lessening. But Pinker puts it eloquently:

"Cruelty as entertainment, human sacrifice to indulge superstition, slavery as a labor-saving device, conquest as the mission statement of government, genocide as a means of acquiring real estate, torture and mutilation as routine punishment, the death penalty for misdemeanors and differences of opinion, assassination as the mechanism of political succession, rape as the spoils of war, pogroms as outlets for frustration, homicide as the major form of conflict resolution--all were unexceptionable features of life for most of human history. But, today, they are rare to nonexistent in the West, far less common elsewhere than they used to be, concealed when they do occur, and widely condemned when they are brought to light."

A heartening reminder.

Slug Sex... Better Than It Sounds

Fact: This is how leopard slugs copulate. Oddly beautiful.



P.S. You also get a rare glimpse of David Attenborough in this video!

What Foxes Tell Us About Hounds

Wolves began the process of becoming Bichon Frises over 10,000 years ago. They inched closer and closer to human camps to live off our refuse. We threw them scraps, and in return their presence discouraged intruders. Of course we had a preference for tamer wolves, and so these were the most often fed and bred. As we selected for this trait, wolves got tamer and tamer - eventually evolving into dogs.

That's the standard story, and yet given the relatively short time period of their evolution, it doesn't address how dogs evolved into forms so drastically different from wolves. How did so many features emerge, such as floppy ears, short snouts, and patchily colored coats, that weren't present in even a minority of wolves in the first place? Why did selecting for tameness result in the saggy-jowled creatures we obsess over today? Can random mutations really result in such rapid change?

A research project that has been taking place in Siberia over the past 50 years has answered many of these questions about dogs... using foxes. By selecting for tameness alone, scientists have created foxes that look and act like dogs. Besides being as tame as domestic dogs after just 40 generations of intensely selective breeding, they have also developed traits that absolutely no one expected to see.

The domesticated foxes' ears began to flop over. Their coats became black and white. They began to bark, wag their tales, and even smell like dogs!

It was found that the tamer foxes had much lower levels of adrenaline than aggressive ones, which explains their weaker fight-or-flight instinct. The connection between adrenaline and tameness has been made previously in the context of dog domestication. But the fox project has revealed that hormones have played a much more complex role than we thought.

For example, in the words of one scientist, "Adrenaline is on a biochemical pathway that also goes to melanin" and thus affects coat color. Many or all of the changes seen in these domesticated foxes - barking, flopping ears and rising tails, smell - can be traced to hormonal changes that are intricately linked to the one affecting tameness. So we didn't necessarily select for black patches on a white body, or the wet-dog smell. Those things just came part and parcel with the trait we did select for.

Domesticated silver foxes can be purchased here; proceeds go to the Siberian project which has no other source of funding and, unfortunately, may have to shut down.

Sloshes of Sound

There are no particles of sound. It doesn't enter our ears in the way that photons enter our eyeballs. Rather than possessing physicality, sound is merely an impression we get from our surroundings. When we "hear" a sound having some pitch and volume, air molecules are vibrating against our ear drums with oscillations of a certain frequency and amplitude.

The vibrations originate from an object in rapid motion - like a bee's wing or a violin string. The moving object knocks air molecules outward away from it. These collide with others farther away, which collide with others even farther out, and so on. The initial outward push gets carried away from its source by a domino effect of molecular collisions.

When molecules hit your ear drum it registers just how hard they hit, and your brain interprets this as the volume of the incoming sound. Your ear drum also registers the frequency of the molecular impacts, which your brain interprets as pitch.

To really see that sound comes from air molecules sloshing back and forth, watch this short video. A loud sound is blasted from the speaker toward a wine glass. Air molecules oscillate with enormous amplitude, pushing periodically against the glass like ocean waves against a cliffside. Under the stress of the impacts, the glass breaks.

Scissor Hands, Bus Bodies

I am in awe of all Florentine bus drivers. With unfaltering nonchalance, they maneuver massive vehicles through cobblestone streets the width of alleyways, whip around corners with centimeters of clearance, and narrowly avoid collisions with a constant barrage of nuns on bicycles and bewildered tourists. Like a medieval knight's sword, the bus seems an extension of its driver's body and mind.

How can humans get so good at driving? And how can chefs be so fast at chopping, and baseball players so good at swinging bats at exactly the right millisecond?

Yet again, kudos are owed to the human brain. Recent research shows that within a matter of minutes of operating a tool, your brain starts to integrate it into its map of your body. The tool actually does become an extension of your body, according to your mind. You become spatially attuned to the tool as if it were a new limb.

French neuro-psychologist Lucilla Cardinali has conducted a series of experiments investigating how tools affect the way we move. After getting used to picking up objects with a claw at the end of a rod, her test subjects spent several minutes readjusting to the normal lengths of their arms. This showed that the claw tool had been temporarily integrated into the brain's perception of arm length.

In one experiment Cardinali asked each test subject to point his or her finger directly above various positions, first with the claw tool then without. Going back to using their normal arms after using the tool, subjects greatly overestimated the lengths of their arms, bending their elbows in such a way that their index fingers hovered far short of their sought positions.

We've been using tools for so long that our brains have learned to integrate them without a (conscious) thought. And like always, practice - enough swings of a bat, or swerves of a bus - makes perfect.

The Ins and Outs of the Universe

No time for a full post today, but here's an awesome website where you can zoom in and out on the Universe and get a sense of the relative sizes of things. It's really cool.

Four Colors Suffice

In 1852, Francis Guthrie was coloring in a map of the counties of England. To ensure that the borders between counties were perceptible, his rule was never to fill in neighboring counties with the same color. To his surprise, Guthrie noticed that he only needed four colors to do this; no matter how complicated the configuration of English counties, a fifth colored pencil was never required to distinguish between neighbors.

Guthrie discussed his observation with his brother, a student of mathematics, who in turn asked his professor about it. But they could find nothing written about Guthrie's “four color theorem.” Somehow thousands of years of geometry and cartography had failed to notice the extremely simple fact that on a two-dimensional plane, no more than four shapes can all touch one another - the reason behind the theorem.

When I was 10 I heard tell of the four color theorem, and was occupied for several days with the task of disproving it. I created incredibly complicated arrangements of shapes: subdivided circles with moats around them, bridges over the moats, moats around the moats, etc. “This is it!” I would say of my latest drawing, before noticing the way in which the fifth color I had used could be obviated.

Mine was an impulse shared by many. In the 150+ years since Guthrie's observation, mathematicians have searched frantically for counter-examples to the four color theorem. None have stood up to scrutiny, but until very recently, neither had a satisfactory proof. It wasn't until 1976 that Kenneth Appel and Wolfgang Haken, with the help of a powerful computer, offered a proof of the theorem that has not since been disavowed.

Their proof asserts that any arrangement of shapes is geometrically equivalent to one of 1,936 arrangements (later reduced to 1,476). One thousand hours of computer processing proved that the four color theorem holds for those arrangements, and so it must hold in general.

Appel and Hankel's computer-based proof was so complex as to be considered impossible to check by hand. Though some mathematicians still have their doubts about it, the proof has nonetheless gained wide acceptance, and has been corroborated by several other computer-based methods.

However, a simple and elegant proof of the four color theorem eludes us. This creates a situation which is rather unique in mathematics: A bit of earnest doodling convinces anyone that the theorem is true, and yet centuries of searching by the best people around has yielded no straightforward explanation as to why.

Any ideas?

Bug Scans

The Scanning Electron Microscope is a magnificent tool. It sweeps a beam of electrons over the surface of an object and detects the electrons and light that scatter back from it. By comparing the information that comes back to what was sent out, it forms a picture with features as small as a single nanometer (10^-9 meters).

I once discussed the way in which scale relates to understanding: we cannot fathom the microscopic or the enormous, or hear patterns in sounds that are too fast or slow. By magnifying extremely small objects to our own scale, Scanning Electron Microscopes enable understanding of a world that was previously inaccessible. Insects, for instance, whose foreign size is fear-inducing, are rendered beautiful when their features can be distinguished.

Portrait of a honey bee. Click here for 12 more incredible insect images at The Telegraph.

What's in a Name

Think of all the millions of times people have addressed you by name. It's a word that follows you everywhere, like an audible shadow. As a result your very sense of self becomes strongly tied to what you're called. Your name occupies pride of place in the language region of your brain, and from its central vantage point it exerts a broad sphere of influence.

Indeed it may influence the entire course of your life. Psychologist Brett Pelham has spent the last decade investigating the question: "what's in a name?" and has found many reasons to conclude that the answer is "a lot."

Names seem to influence a person's choice of occupation. For example people named Denis, Denise, and Dena are overrepresented among dentists. The idea that a person would become a dentist because the word sounds like his or her name seems absolutely ridiculous. And yet with a large enough sample size (the entirety of 1990 U.S. census data), the subconscious influence of a homophone is noticeable.

Furthermore, names play a part in who we marry. More often than would be statistically predicted, two people marry whose last names begin with the same letter.

And, according to Pelham, names influence where we choose to live. People named Philip are disproportionately likely to live in Philadelphia, as are women named Mildred in Milwaukee. Personally I would interpret this finding to mean that the naming of babies is influenced by the cities of their birth, rather than the other way around. But the connection is strange in either direction.

In Pelham's view, name-centric life decisions stem from the positive opinions we have of ourselves. But I think a meaningful interpretation is harder to come by than the data. For now, all we know is this: A rose by any other name would probably still smell as sweet, but if my step-dad's surname weren't Lawrence, he might not have become a lawyer.

To Be Plagued, or Not to Be

Halfway into the 14th century Europe was ravaged by the bubonic plague, or Black Death. In the words of Barbara Tuchman in her fantastic book A Distant Mirror:

"So lethal was the disease that cases were known of persons going to bed well and dying before they woke, of doctors catching the illness at a bedside and dying before the patient. So rapidly did it spread from one to another that to a French physician, Simon de Covino, it seemed as if one sick person 'could infect the whole world.'"

Altogether one third of the population of Europe succumbed to this horrible illness, dying with black buboes bursting from their armpits, necks, and groins. As it spread across the continent in the bodies of fleas, rats, and people, whole villages were wiped out. "In enclosed places such as monasteries and prisons," writes Tuchman, "the infection of one person usually meant that of all." One Sienese chronicler noted that the Black Death, when it arrived in a given place, was so thorough that "nobody wept."

But obviously not everyone died. Why not? What stopped the Black Death in its tracks, after a reign of terror lasting just two or three years? And in general, what limits the scope of an epidemic?

A hint comes from another time when the Black Death surfaced (as it did periodically for the next few centuries), in England in 1665. When cases of the disease were reported in the village of Eyam, the villagers decided (rather heroically) to quarantine themselves to prevent the plague from spreading. It was believed that they would all die. However, a year later when they lifted their self-imposed quarantine, half the population remained.

Recent research shows that the community (and its present-day descendants) had a high incidence of a mutation known as "delta-32." By changing the structure of white blood cells, this mutant gene prevented plague bacteria from hijacking them and turning them against their hosts. People with the delta-32 mutation were, in all likelihood, immune to the plague.

Amazingly, it is this same mutation that makes humans immune to HIV when they inherit it from both parents, or resistant when they inherit it from one. About 10 to 15% of people descended from Northern Europeans have at least one copy of the delta-32 gene, and are thereby unlikely to get HIV/AIDS.

This is the legacy of their ancestors, who stood by as the world around them succumbed to history's worst epidemic.

Best Wishes

In the 1660s, Robert Boyle, "the father of chemistry" and one of the founders of the Royal Society, wrote a to-do list for humanity. It included 24 items which he considered to be of highest scientific priority. In the context of what was possible in his day, Boyle's wishlist is truly visionary. Even more remarkable is how well we've done in the 350 years since: 21 of the 24 items on the list can be checked off.

Here is Boyle's wishlist, annotated with our corresponding accomplishments by Richard Alleyne at the Telegraph.

1. The Prolongation of Life.

2. The Recovery of Youth, or at least some of the Marks of it, as new Teeth, new Hair colour'd as in youth – Botox, plastic surgery, teeth-capping, hair dye and transplants.

3. The art of flying – aeroplanes.

4. The Art of Continuing long under water, and exercising functions freely there – submarines and scuba diving

5. The Cure of Diseases at a distance or at least by Transplantation – transplantation and keyhole surgery

6. The Emulating of Fish without Engines by Custome and Education only – Free diving

7. Great Strength and Agility of Body exemplify'd by that of Frantick Epileptick and Hystericall persons – anabolic steroids and barbiturates.

8. The Acceleration of the Production of things out of Seed – genetically modified foods and hydroponics

9. The making of Parabolicall and Hyperbolicall Glasses – spectacles and telescopes

10. The making Armor light and extremely hard – Kevlar Body armour

11. The practicable and certain way of finding Longitudes – GPS

12. Potent Druggs to alter or Exalt Imagination, Waking, Memory, and other functions, and appease pain, procure innocent sleep, harmless dreams, etc

13. Pleasing Dreams and physicall Exercises exemplify'd by the Egyptian Electuary and by the Fungus mentioned by the French Author – hallucinogenic drugs

14. Great Strength and Agility of Body exemplify'd by that of Frantick Epileptick and Hystericall persons – performance enhancing drugs

15. A perpetuall Light – electric light

16. Varnishes perfumable by Rubbing – scratch and sniff

17. The Transmutation of Species in Mineralls, Animals, and Vegetables – synthetic biology and genetic engineering.

18. The Attaining Gigantick Dimensions – eve bigger people, animals and plants

19. The makeing of Glass Malleable – sophisticated glass making

20. Freedom from Necessity of much Sleeping exemplify'd by the Operations of Tea and what happens in Mad-Men – barbiturates and stimulants to keep you awake.

21. The use of Pendulums at Sea and in Journeys, and the Application of it to watches – quartz watches

Still to be achieved:

22. The Cure of Wounds at a Distance – Star Trek style healing devices.

23. The Transmutation of Metalls – nuclear physicists have transformed some metals slightly though turning lead into gold still impossible

24. The Liquid Alkaest and Other dissolving Menstruums – invention of a universal solvent

The Royal Society is meeting this year to reassess its past, and perhaps, set out a new to-do list for future scientists. It seems that outrageous ideas ought to be included.

Reality Check: Negative

When you're not looking at the kitchen table, is it still there? If a tree falls in a forest devoid of ears, does it make a sound? Scientists and philosophers have debated these questions for millennia. Is there an external reality, they are asking, that exists independent of observation?

It seems the answer is no - that is, at least, on the subatomic scale. Using a complicated experimental apparatus, a group of Austrian physicists led by Anton Zeilinger recently investigated whether particles possess definite properties even when we aren't measuring them. They found that in fact they do not; when we aren't looking where they are, in what direction they're polarized, or how fast they're moving, fundamental particles (like electrons and photons) have no such traits.

If this seems strange to you, you're not alone. A lot of scientific and historical context is required to feel even slightly comfortable with the subject of quantum physics, and that's the best you'll ever feel. Nonetheless here's a bit of back story on this latest development.

Quantum physics began chipping away at our notions of reality decades ago when a principle called “local realism” was invalidated. Local realism is the belief that not only is there an external reality, but it cannot be immediately influenced by events very far away. It would hold, for example, that you couldn’t possibly know about an event taking place on the other side of the world until the message has had time to get to you. At the very least, enough time must pass for light to travel between the two places.

But then it was demonstrated in the 1970s that fundamental particles can become “entangled”. This means that the experiences of one instantaneously affect the state of another, even after the particles have been separated far enough apart that a signal has no time to travel between them. Since whatever happens to one particle instantly determines the traits of the other, it is as if the particles have no independent traits. In other words, entangled particles seem to share a simultaneous connection. This result, which has been verified time and again, shattered assumptions of local realism.

Physicists were prepared to discard the principle of locality in order to keep physical realism intact. They formulated a modified theory of “non-local realism” accordingly. If particles were trees, non-local realism would have it that their root structures can become entangled deep underground, and in this way, what happens to one tree instantly affects the other. Though they are hidden from us, roots bridge the distance between the two trees, explaining their non-local behavior – or so the theory holds.

A clever test of non-local realism has just been performed by Zeilinger and his research team. They split light from a laser into pairs of entangled photons. These were sent their separate ways through optical devices and then into detectors, which measured certain properties of the entangled photons. The experiment was set up so that the amount of correspondence between their polarizations would reveal whether or not there is a non-local reality.

The results came up negative. In the concluding remarks of his 2007 paper in Nature, Zeilinger asked humankind to “abandon certain features of realistic descriptions”. A radical departure is certainly necessary to accept that, on the quantum scale at least, there is no reality. Fundamental particles have no definite energies, no positions – in short, no existence – until someone is making measurements.

While settling one question of the ages, Zeilinger’s result raises others: Why does reality seem to emerge on the scale of kitchen tables, trees, and people - and how?

Pitch Perfect

by Serena Le (guest blogger)

I was sitting in a music history seminar one dreary afternoon, fluorescent lights buzzing overhead, when I noticed the young fellow opposite me making a series of increasingly pained grimaces. During a lull in the discussion, he caught my eye and gestured at the ceiling. “This light is driving me crazy,” he said. “It can’t decide whether to be a B or a B-flat.” Sure enough, on closer listen, what had seemed little more than a faint background hum became a nearly unbearable oscillation between not-quite-pitches, one of which was most certainly a botched B-flat. My tablemate looked about ready to bolt from the room.

As we’ve previously noted, our ability to register sound gives us access to all sorts of information about the world around us, and the more we come to understand about human hearing, the more remarkable it seems. One point of interest, still largely a mystery after all these years, is what we call absolute (or “perfect”) pitch. Those who possess it in its strongest form (my poor light-plagued acquaintance included) can accomplish all manner of sound-based feats — naming or singing any note out of a thin air, for example, or playing an unfamiliar melody by ear without first being given a starting note or key — and are frequently musicians of the enviable variety.

But one does not have to be a musician to have absolute pitch (nor does musical ability guarantee the strength of one’s pitch recognition). Recent studies suggest musicians have absolute pitch at a rate approximately 200 times that of the general population, but because our methods for determining absolute pitch rely most frequently on pitch recognition as musical tones, individuals with no musical training may never discover the full extent of their gift. Pitch is merely our term for the quality of a sound governed by the rate of vibrations producing it; the precise science behind what is frequently called pitch perception or pitch “memory” remains unclear. Research scientists like Daniel J. Levitin theorize pitch as a purely psychological phenomenon: although sound waves most certainly exist and are possessed of frequency and amplitude, pitch is created in the brain of the perceiver alone. How sound becomes distinct as tone is the as-yet-unfinished work of 'psychoacousticians'.

Consequently, scientists have yet to reach any sort of consensus on the number of people in possession of absolute pitch. According to neurologist and author Oliver Sacks, the ability occurs in maybe one out of every 10,000 people. UCSF, meanwhile, is running a study to determine possible links to genetics. So far, the study has shown that musically trained siblings of absolute-pitch-possessors prove about 15 times more likely to have absolute pitch than do individuals with no family history of absolute pitch, however musically inclined. For more detailed findings and the opportunity to test your own pitch recognition with their free sound quiz, head on over to the site itself.

Needless to say, the field for pitch study remains vast and vibrant, and our understanding of absolute pitch is still in its infancy. New research is even in the process of investigating intriguing overlaps between the possession of absolute pitch and the speaking of certain tonal languages. And if living in a world of perpetually pitched noise seems at times excruciating, I imagine it’s worth it for the perks. Last year, for instance, I was attending a lecture with a friend of mine when something screeched against the wall in the next room. “What on earth was that?” I hissed, having jumped near out of my skin.

“Oh,” she said, already smug. “Sounded like an F.”

Too Beautiful

After visiting Florence in 1817, the novelist Stendhal wrote, "I was in a sort of ecstasy, from the idea of being in Florence ... Absorbed in the contemplation of sublime beauty, I had palpitations of the heart ... Life was drained from me. I walked with the fear of falling."

Tourists experiencing the Renaissance wonders of Florence very often become disoriented and overwhelmed by the beauty and historical significance of what they see. The condition even has a name: Stendhal syndrome, after its first known patient. It can vary in severity from tingling sensations and crazed gasps at the sight of the Duomo or Michelangelo's David, to actual madness.

A handful of cases on the more severe side are diagnosed in Florence each year. One recent case was that of Mary, a school teacher who visited the city in the 1980s and spent the entire four days of her trip in the psychiatric ward of a hospital.

I arrived in Florence two days ago for a six week stay. I would describe my own case of Stendhal syndrome as mild but extant. Aside from the almost unbearably beautiful works of art and architecture that changed the course of human history, the pasta and gelato are pretty overwhelming too.

Outlier Week: The Things People Do

Enough about unusual brains already; it's time to talk about outlandish brawn.

Considered by many to be the world's toughest sporting event, the Race Across America (RAAM) will commence a few days from now. The course of this 3,000-mile coast-to-coast bike race varies each year; this time riders will begin in Southern California, ride over the Rocky Mountains, traverse the desert, plains, and Appalachia, and cross the finish line in Maryland. If I had to drive such a route I'd probably stretch it out to ten days or so to make it bearable. But how many days will competitors take to bike it?

About eight.

Biking. It strikes me as unbelievable. Don't they sleep? The answer is no. Most long-distance bike races such as the Tour de France are divided into sections separated by rest periods. In the Race Across America, though, the timer ticks from start to finish, and that makes getting a good night sleep a terrible idea. The top competitors ride for an average of 22.5 hours a day, eight days in a row.

As an eight-hours-of-sleep-every-night type of person, as well as a not-biking-500-miles-in-a-single-day-type of person, I just don't understand how this race is humanly possible. Biking over the Rockies with a couple of power naps and a power bar? Sleeping for an hour then traversing the Great Plains?!

Sleep deprivation does play a major part in this competition. An article about four-time RAAM winner Jure Robic describes the race like this:

The craziness is methodical ... and Robic and his crew know its pattern by heart. Around Day 2 of a typical weeklong race, his speech goes staccato. By Day 3, he is belligerent and sometimes paranoid. His short-term memory vanishes, and he weeps uncontrollably. The last days are marked by hallucinations: bears, wolves and aliens prowl the roadside; asphalt cracks rearrange themselves into coded messages. Occasionally, Robic leaps from his bike to square off with shadowy figures that turn out to be mailboxes. In a 2004 race, he turned to see himself pursued by a howling band of black-bearded men on horseback.

‘‘Mujahedeen, shooting at me,’’ he explains. ‘‘So I ride faster.’’

As frightening as they sound, the hallucinations can be no worse than the reality of this race. And yet the number of RAAM competitors grows every year.

Outlier Week: Hearing Things

I am so sight-centered that I never even realized the full potential of my sense of hearing. Apparently I, and you too, have the capacity for echolocation. Yep, sonar. Most blindfolded people can detect the presence or absence of objects in front of their faces (with a little practice) simply by humming. We are sufficiently sensitive to the echoes. Who knew!

Since human echolocation is possible, of course there are those who've taken it to the extreme. Top of the list is Ben Underwood. After having his eyes removed as a toddler, Ben began making clicking noises with his mouth and listening carefully to how the sound waves bounced off of his surroundings. Echoes helped him construct mental pictures of the world, in which he became incredibly mobile:

Ben was famously good at echolocation, but it is actually common among blind people and considered by many to be one of the most important skills they can learn. If you learn sonar at a young age, does your brain dedicate more of its resources toward hearing than most people's? No one is sure. It might just come down to getting more practice.

How does human echolocation at its best compare to that of a bat? Well it's certainly not as good, since the pitch of a human mouth click is so much lower than a bat's screech. Because the frequency of the sound wave we emit is much lower, there is a greater distance between successive peaks on the wave. Since this distance - the wavelength - defines the scale of measurement available for us to use, we can get only a much rougher sense of size and location of objects than a bat does, with its high frequency, short wavelength sound.

Outlier Week: Baby Talk

We're now going to clamber over to the opposite rim of the language acquisition bell curve. At the right extreme, dangling from the edge by a single handhold, we find Kim Ung-Yong, a Korean with the highest IQ in the world at 210.

Kim was born in March 1962 and started speaking 6 months later. He was fluent in Korean by age 1, and knew four languages by the time he was 3. By 4 Kim was studying physics at university. The media got wind of the child prodigy and had him solving complicated calculus integrals live on television that same year, as pictured.

At 7 Kim came to the United States to be educated and began conducting research at NASA by age 12. He earned his PhD at 15 and returned to Korea soon after, where he switched fields from physics to civil engineering. He then seems to have faded somewhat into academic obscurity, at least on the international level.

This result is so very common with wonder children - why? In a book on the subject, psychologist Ellen Winner put it like this: "The skill of being a child prodigy is the skill of mastering something already invented. The skill of being a major creative adult requires innovation, rebelliousness, and dissatisfaction with the status quo."

These forms of intelligence don't necessarily overlap. You just can't measure a rebel with an IQ test.

Outlier Week: L'Enfant Sauvage

Oxana Malaya grew up with a pack of dogs. Her impoverished, alcoholic parents abandoned her as a 3-year-old on the streets of the Ukrainian village where they lived. She took up with some strays inhabiting a nearby shed, not to reenter the human world again until age eight.

Here is some footage of Oxana some time after she was found by authorities in 1991:

Feral children like Oxana show us just how adaptive the human brain really is. Her critical years weren't spent learning language, socionormal behavior, or intellectual processing. Instead her brain put its resources toward cultivating acute senses of hearing and smell, and perfecting the mannerisms of the dogs who fed and cared for her.

Since Oxana's return to human society she has been living in a home for the mentally handicapped. Her case is of great interest to linguists and neuroscientists. The rather modest results of efforts to rehabilitate her seem to support the "critical period hypothesis" of language acquisition. Though she has learned rudimentary Russian, she will never develop the linguistic capabilities of an average human, having missed a window of opportunity during her early years.

In an interview conducted years after Oxana's return, she reported still feeling happiest in the company of dogs. "It is in my nature," she said.