Field of Science


11 People Trace Synesthesia to One Set of Alphabet Magnets

Most people with synesthesia can't tell you exactly why they perceive the letter M as purple and not orange, or a high C-sharp as bright yellow and not blue. For one group of synesthetes, though, there appears to be an answer. For their green D's, red G's, and so on, they can thank the toy company Fisher-Price.

Stanford researchers Nathan Witthoft and Jonathan Winawer discovered, through word of mouth and from synesthetes contacting them online, a group of people who share a "startlingly similar" set of letter-color associations. Out of the eleven subjects, ten remembered owning (or still owned) a particular set of alphabet refrigerator magnets that was manufactured in the 1970s and 1980s.

The leftmost column below (labeled "set") shows the actual colors of this toy. The colors that the eleven subjects associate with the alphabet are listed as S1 through S11, in order of how well they match the magnetic letters. (And to the right are the magnets themselves.)

Subject S1 was carrying around mentally a perfect replica of the Fisher-Price letters, as the authors report in Psychological Science. The others had some differences—but were close enough to the toy's colors that, the researchers figure, it can't be a coincidence.

All eleven subjects also had number-color synesthesia. For the numerals 0 through 9, five of these people turned out to have color associations that matched sets of magnetic numbers sold along with some Fisher-Price alphabet sets.

Witthoft and Winawer don't think the magnets themselves made anybody synesthetic. But among this group of people who became synesthetic (and they may have been predisposed; it runs in families), many of the associations they learned came from a childhood toy.

Not that synesthesia should be confused with memory. Someone with synesthesia doesn't recall the color green when he sees the letter K the same way he sees Kansas and recalls that Topeka is the capital. Instead, synesthetes automatically experience that color when they read that letter or number (or experience a taste when they hear a sound, among other rarer combinations). Some even see the color on the page.

The authors say that the case of the Fisher-Price magnets shows synesthetic associations can be learned, rather than plucked from nowhere by the brain. "The idea that the colors would be learned has been around for a long time," Witthoft says, "but it has been difficult to turn up any examples." In this case, a mass-produced toy—combined with the powers of the Internet—helped.

But they don't think most synesthetes learn their associations from objects around them. These people appear to be, the researchers write, "anomalies among the anomalous."

When the colors of these subjects' mental alphabets differed from the Fisher-Price letters, it was often in ways that made them less anomalous—that is, more like the synesthetic population in general. "Color-grapheme synesthetes as a group have some shared tendencies," Witthoft says.

For example, 40 to 50 percent of English-speaking synesthetes associate the letter Y with yellow. Out of three subjects in this study who deviated from the red Y of the magnets, two went to yellow. It's also common to associate the letter X with black, as four subjects did (deviating from Fisher-Price purple).

Besides yellow Y's, studies have also found a lot of red R's, blue B's, and violet V's among synesthetes. These associations seem to come from language. The origin of most connections, though, is still mysterious.

One study, Witthoft says, argues that the brightness of a synesthetic color is related to how common that letter or number is. Other research "suggests that letters with similar shapes end up with similar colors." And in some types of synesthesia, he says, there are hints that the associations come from some basic way the brain is set up. For example, "pitch-color" synesthetes tend to see higher pitches as brighter colors. Non-synesthetes, if asked, make the same connection.

For now, childhood toys seem to be only a small part of the answer. To help dispel more of the mystery, you can take tests for synesthesia at—even if you weren't a Fisher-Price kid.

Witthoft, N., & Winawer, J. (2013). Learning, Memory, and Synesthesia Psychological Science DOI: 10.1177/0956797612452573

Images: Manon Paradis (Flickr); Witthoft & Winawer.

How to Cross the Deep Sea: Stepping Stones of Mollusk Poop

The seafloor has no shortage of spiky wildlife or hairy mysteries. One such mystery is logistical: where do the animals that live around deep-sea vents and cold seeps come from?

On the black and generally barren bottom of the ocean, food is scarce. Hydrothermal vents and cold seeps—places where methane, sulfides and other chemical goodies leak out of the seafloor—are like desert oases. Whole communities of weird creatures that live on these chemicals rather than the sun cluster around them.

Researchers think big pieces of organic junk that fall to the bottom of the ocean, such as sunken ships and deceased whales (called "whale falls"), may act as stepping stones for these communities. Species might disperse from one seafloor chimney to the next via a visit to a wrecked ship.

"Wood is a foreign substance in the deep sea," says Christina Bienhold of the Max Planck Institute. To find out whether resourceful ocean critters can easily make use of wood that falls into the ocean, she and other researchers dropped some in. They rigged together small heaps of Douglas fir logs, weighted them with cement, and carried them a mile down into the Mediterranean.

The researchers used four wood piles, each two meters long. They were at various distances from a known cold seep. The closest log was 70 meters away—so if any animals scooted over from that community, it would be a bit of a trek.

One of the wood heaps was sampled just one day later. (It looked the same.) The other three rested on the ocean floor for a year before robotic vehicles returned to collect wood samples and scoop up the animals that had moved in.

And did they ever move in. Bienhold was surprised to find that her logs, after only a year on the seafloor, held thriving colonies of wildlife.

The logs' most abundant tenants were wood-boring bivalves called Xylophaga, or "shipworms." Built like a worm with a shell on one end, these mollusks burrow into wood while symbiotic bacteria help them digest it. All around the logs were evidence of their work: the researchers observed a layer of "fine wood chips and fecal matter" two to four centimeters thick.

The shipworms seemed to have attracted other animals interested in feeding on the mollusks themselves or on the waste piles they left everywhere. As these creatures ate and respired, they used up oxygen in the water and allowed oxygen-hating bacteria to move in. These bacteria created pockets of sulfides—food for the kinds of animals that live at cold seeps or hydrothermal vents. (Normally, they would find this food coming straight out of the ground.)

Like very unattractive doves out of a hat, those animals began to materialize out of the blackness of the ocean. Clustered around the logs were sea urchins, fish, and deep-sea mussels and crabs. There were small crustaceans that couldn't be identified, and several types of worms, including two brand-new species.

All three wood piles had similar animal communities living on and around (and, in the case of the crabs, hiding underneath) them. Their bacterial communities were more diverse. But they all included bacteria that could break down the cellulose in wood, as well as bacteria that consume sulfate instead of oxygen.

Bienhold says her results show how wood that falls to the seafloor can create hotspots of ocean life. Hunks of organic trash like her log piles, even though they're few and far between on the bottom of the ocean, could help rare deep-sea species to spread. The key player in her set of experiments was the little wood-boring bivalve that moved in first and made the logs into a habitat that other wildlife could use.

"It remains enigmatic," Bienhold says, how the wood-borers (or any of the other organisms) found this new habitat in the first place. The researchers observed a greater density of sea urchins as they got closer to the wood piles; they seemed to be attracted to the wood by some chemical signal. Sea urchins and other animals may sniff out chemical cues from afar that help them find organic matter. For now, though, the secret remains sealed in their lipless bodies.

Bienhold C, Pop Ristova P, Wenzhöfer F, Dittmar T, & Boetius A (2013). How deep-sea wood falls sustain chemosynthetic life. PloS one, 8 (1) PMID: 23301092

In Our Partners' Heights, We Get What We Want

If you ask most heterosexual people what height they're looking for in a partner, they'll describe basically what a children's-book illustrator would draw: the man taller than the woman but not towering over her. But those of us who aren't pen-and-paper must settle for real human partners in human shapes and sizes. Nevertheless, new research says most people end up with a reality that matches the fantasy.

Researchers led by Gert Stulp of the University of Groningen in the Netherlands wondered whether people's professed height preferences matched who they ended up with. Earlier studies had shown that within Western cultures, there are clear trends: Taller people are interested in other tall people; shorter people like short people. And both sexes prefer that the male be taller.

But not too tall! One study combed through thousands of personal ads from a dating site that let users indicate the tallest and shortest person they'd consider dating. On average, women said they weren't interested in men more than 17% taller than themselves. For a 5-foot-5 woman, for example, that means  a man over 6 foot 4 seems like a little much.

To compare these preferences to a real population, Stulp and his coauthors used data from the Millennium Cohort Study, a broad sampling of almost 19,000 babies born in the United Kingdom in the year 2000. Among other things, the parents of these babies had been asked for their heights, and 12,502 couples had answered the question.

To see what it would look like if people paired off with no regard to height, the researchers created 10,000 random reshufflings of their UK couples. They then compared these chance pairings to reality.

First, they tested whether people seek out their own kind. Sure enough, taller people had taller partners, and shorter people had shorter partners.

The next question was whether people really care about the man being taller. Of course, since men are on average taller than women, randomly pairing people off is likely to get you a taller male anyway. In the randomized UK couples, the male was taller 89.8% of the time. But in reality, 92.5% of couples had a taller male, a significant difference. And when the woman was taller, it was likely to be only by a tiny bit.

Finally, people say they prefer height differences that aren't too exaggerated. But do they follow through? The authors looked for height gaps of 25 centimeters or more. In the random pairings, this occurred in 15.7% of couples. But in real life, only 13.9% of couples had a height difference this huge.

More often than chance would predict, these couples had followed traditional height preferences. That suggests that when we choose our partners, height does matter.

The study doesn't address the preferences (or reality) of couples who are not heterosexual, not parents, or not in the United Kingdom. Stulp says research has shown that across Western cultures, heterosexual people report very similar preferences for a partner's height. (The Netherlands, where the 6-foot-7 Stulp lives, is home to the tallest people in the world. But he says he believes height preferences in this land of giants are the same, just shifted upward.) In non-Western cultures, he says, those preferences are slightly different and more variable.

Stulp, in fact, was surprised that height preferences didn't have an even stronger affect on the results. He expected reality to be further from random chance than it was. But, writing in PLOS ONE, he acknowledges that many factors affect our choice of partner. "Height," he writes, "is but one of many characteristics valued in a mate."

Stulp, G., Buunk, A., Pollet, T., Nettle, D., & Verhulst, S. (2013). Are Human Mating Preferences with Respect to Height Reflected in Actual Pairings? PLoS ONE, 8 (1) DOI: 10.1371/journal.pone.0054186

Image: Peter Rukavina (Flickr)

This Penguin: An Unexpected Journey

The humble king penguin chick had no way of knowing, when it woke up that day, that tall creatures from far away would come to send it on a journey. Nor could it know that its journey would become the subject of a manuscript read and studied by many. (It still doesn't know that part, because it's a bird.) 

When the humans came, the penguin was in its crèche, a cluster of young birds left behind while their parents foraged. Other penguins young and old stretched away from it in all directions. All at once, the chick was lifted from the ground by a pair of human hands. A cloth hood was pulled over its head. The researcher spun the bird around three times, then set off, carrying the bird away from the colony at a fast clip. 

Human and penguin traveled a circuitous route meant to further disorient the bird. When they reached their destination, the human spun the penguin three more times. Finally the chick found itself on solid ground, the hood pulled away from its eyes. Its colony was nowhere in sight.

The penguin was standing inside a circular arena about 10 meters across, surrounded by a meter-high wall of cloth. A scientist quickly fitted a pair of pads, like earmuffs, over the chick's head, deadening the sounds it heard. Then the penguin was left alone.

For fifteen minutes, following cues in its head that were inscrutable to the human observers, the penguin wandered inside the arena. Its instincts told it to return to the crèche right away, so its parents could find it when they came back. While it tried to discover the right direction, human eyes watched and recorded. Finally the walls of the arena came down; the bird was free to go.

It set off waddling across the frozen ground, still wearing its earmuffs. The bird was less than 200 meters from the colony but still couldn't see it. The ocean, though, was in sight. The chick walked straight to the shore. Then it hung a left and headed, correctly, for its colony. Finally it reached the crèche and the other chicks it had left behind. A piece of wood was on the ground, left by the human to mark the spot where the penguin had stood before its abduction.

This traveler was only one of many young penguins the humans lifted from their crèches in those days. Some, instead of earmuffs, had magnets temporarily attached to the backs of their heads. Some were made to travel by night. Some heard a recording of the colony broadcast loudly from speakers within the arena.

The researchers, who came from the University of Oxford and the CEFE in France, hoped to learn from the journeying birds the secrets of penguin navigation. Earlier visits to penguin crèches had told them that the young birds navigate partly by sight, but that most of them could still find their way in the dark—so some other talent was at work too.

Chicks with magnets on their heads did not fare any worse than usual. This revealed to the humans that the penguins didn't rely on sensing the earth's magnetic fields (as homing pigeons are able to do). 

The 18 earmuffed birds were also just as likely to navigate home as non-earmuffed birds. But out of the 16 who made it home without help, researchers noticed that 6 took an unusual path. Like our hero, they seemed to orient themselves by first walking to the ocean, then following it back. It was an intriguing hint that the earmuffs, which quieted the sound of the squawking penguin colony but didn't block it out entirely, were changing the birds' navigation strategy.

The second experiment involving sound truly befuddled the young birds. When speakers inside the arena played the sounds of the colony, almost all the penguins oriented themselves toward the speakers instead of toward home (in the opposite direction). Several chicks stood in front of the speakers, calling to them plaintively.

Five minutes after the walls came down, nearly all the undisturbed chicks were well on their way back to the colony. But many of the chicks who had heard the speaker noises lingered close to the arena. A few set off in the wrong direction entirely. 

The humans made sure all the young birds made it back to their crèches in the end. Afterward, lead author Anna Nesterova told the tale of the traveling penguins in the Journal of Experimental Biology.

From her story, Nesterova drew the moral that penguins use acoustic cues as part of their navigational toolkit. The sound of the distant colony seems to call them back. But the visual landmarks around the birds are also important, and there may be other clues they take in as well. 

As adults, king penguins must navigate between the colony (which may span several kilometers) and their foraging grounds. Upon returning to the colony, they find their partners and chicks by calling out and listening for the right voices among thousands—a task that would seem to require magic. Someday, we meddling humans may learn the secret of how these birds get there and back again.

Nesterova, A., Chiffard, J., Couchoux, C., & Bonadonna, F. (2013). The invisible cues that guide king penguin chicks home. The use of magnetic and acoustic cues during orientation and short-range navigation Journal of Experimental Biology DOI: 10.1242/jeb.075564

Images courtesy of Anna Nesterova.

The Shambulance: Enough Already with the Juice Cleanses

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. Helping me chart a course are Steven Swoap and Daniel Lynch

Before I learned that it costs $65 to $90 to starve yourself for a day, I considered trying one day's worth of "juice cleansing" to put myself into the proper cranky fog for writing this piece. But if I'm going to eat no calories, I prefer to spend no dollars. 

What did I give up by fueling myself on solid foods instead of liquefied produce? Really, one day would have been merely dipping a toe into the celery water. If I were a serious client of a juice cleanse company, I would pay for anywhere from three to ten days' worth of bottled juices, delivered to my doorstep in a cooler every morning. 

The first few days of deprivation would, in theory, "cleanse the blood" and release toxins from my tissues that have been slowing me down and making me sick. I'd give my colon a break while "sweeping" it out. The latter days would boost my immune system and "fight off degenerative diseases." After all that detoxifying and boosting, I would feel energized and restored. I might even have lost a few pounds—but it's about health, not weight.

In the midst of my cleanse, I could experience unpleasant symptoms. "Don't Panic," the website for BluePrintCleanse would reassure me, "It's Just A Healing Crisis!" Apparently, a body that's becoming healthier looks a lot like one that's unwell. Symptoms of detox may include fatigue, headaches, nausea, hives, decreased bowel movements, increased bowel movements, strangely colored bowel movements ("Did you just drink some of our beet juice?"), dry mouth, runny nose, and canker sores. I should ignore those symptoms, drink herbal tea, and be reassured that I'll soon be skinnier. Sorry, healthier.

I sent some promotional materials on juice cleansing to Steven Swoap and Daniel Lynch, both biologists at Williams College. "Where to start?" Swoap said.

The subject of "cleansing" has been covered on this site ad nauseam (not to mention ad headache, ad fatigue and ad canker sores). But to recap, your body does its own cleansing via your kidneys and liver. The wastes and unwanted materials those organs filter out leave you via the toilet—not through your sweat glands or the soles of your feet or water blasted up your colon. And depriving yourself of calories doesn't make the process go any faster.

If anything, it's the opposite, because fasting slows your metabolism. BluePrintCleanse claims that the energy you save on digestion by not eating any real food gets diverted to "other metabolic processes." But Swoap says this is false. Your whole metabolism will slow at once, not just the tasks attached to digesting food. This will make it harder to lose weight. 

The same website reassures users that they won't feel light-headed during a cleanse: "On the contrary, one's mind becomes clearer and one's ability to solve problems enhances." All the blood and oxygen you would normally use to process your food, it explains, get sent to your brain instead.

"Wrong," Swoap says. "The same amount of blood and oxygen is delivered to the brain under nearly all conditions." Reducing your calories won't send more blood to your head. Actually, fasting can make your blood pressure drop, which is the one circumstance in which less blood will reach your brain. 

So much for that clearer mind. In an article from the Boston Globe on juice cleansing companies, registered dietician Marjorie Nolan Cohn says that after a few days of fasting, "you become lightheaded and dizzy, and that euphoric feeling starts to come on." She adds, "I work with a lot of anorexics, and they feel euphoria, too."

Company websites are quick to insist that juice cleansing isn't fasting, even though their plans may provide under a thousand calories a day. And of course it's not about the weight loss—unless you're a bride-to-be. In that case BluePrintCleanse encourages you to "Drink your way to your best shape ever" before walking down the aisle. 

The company offers bridal packages ranging from six to thirty-six days of juice. Elsewhere on its website, it recommends you consult with your doctor before spending more than ten days on a cleanse. But when I emailed to ask how many solid food breaks are in a thirty-six-day juice program, a representative replied that I could schedule my days however I liked. "If you don't use all the juice days before your wedding, you can save them for after your honeymoon," she said. But I'm also free to schedule five consecutive weeks of fasting through the site. 

"Congratulations!" the representative wrote. By the way, that package would be $2,415.00. 

"In reality, for a healthy person to blow a bunch of money to purchase the juices and drink them over a couple days is probably not harmful," Daniel Lynch says. (The operative words being "a couple days.") "And if it serves as some motivational tool to eat better, etc., it is fine." But if your goal is to give your digestive system a rest, he adds, "why not go with an IV bag of dextrose?"

And if you're looking to empty your colon, Lynch points out, a cheap laxative will do the trick in about six hours. "Why spend loads of money and suffer through days of drinking liquified kale?" He sounds a little cranky. Maybe he missed a meal.

Image: Food Thinkers (via Flickr)

Captive Animals Act Smarter

In the Kenyan wilderness, hyenas facing a meat-stuffed puzzle box performed impressively—impressively badly, that is. Researchers expected the animals to be up to the challenge, but few of them ever got the box open. Now, repeating the experiment with captive hyenas, they've discovered that there's no contest: the captive animals are better problem solvers.

Out of 62 wild hyenas in last year's study, less than 15 percent ever managed to slide the latch and swing open the door of the barred metal box. Despite multiple chances, most of the animals were losers in this game.

But lead author Sarah Benson-Amram observed certain behavioral traits shared by the winners. Hyenas that tried more techniques to get the box open (biting, dragging, flipping the darn thing over) had greater odds of success. And hyenas that were less "neophobic"—that is, less wary when approaching a new object in their environment—also did better.

Previous studies with primates and birds had suggested that captive animals are both less neophobic and better at problem solving than wild ones. So Benson-Amram repeated her experiment on a group of hyenas living very far from their homeland, in Berkeley, California.

This group was smaller than the wild hyena group, with only 19 animals tested. But three-quarters of them solved the puzzle, Benson-Amram reports in Animal Behaviour. And every successful captive hyena got the meat on its first try—unlike the wild animals, most of which needed more than one trial before they figured it out.

Although the wild and captive animals belonged to the same species, you would get very different impressions of hyenas' problem-solving smarts if you only looked at one group.

Benson-Amram ruled out a few possible explanations for that difference. Did well-fed animals have more energy for solving the puzzle? In the wild, high-ranking hyenas ate more but didn't do any better with the puzzle box. Were hungrier animals more motivated? Skinny hyenas had no advantage either, and captive hyenas didn't lose interest after eating.

Two explanations, though, held up. One was neophobia. In the wild, animals that were more cautious about approaching the manmade box were less likely to crack it open. Captive animals were overall less neophobic than wild ones. This isn't surprising, since they're used to living around humans and our metal objects.

The second notable difference was that captive hyenas tended to try more behaviors (biting, digging, pulling, and so on) than wild hyenas did. Benson-Amram thinks this has to do with distraction.

"It’s almost akin to giving a puzzle to a civilian in an active war zone versus giving one to a person in the comfort of their living room," she says. The wild hyena is busy watching out for predators, rather than wondering whether pushing and biting at the same time might get this box open. "The person in the war zone would likely give much less mental focus to the puzzle since they have to constantly look over their shoulder," Benson-Amram says.

Or maybe the comfortable home isn't the right analogy for the captive hyenas.

"Imagine giving a puzzle to a person in solitary confinement," Benson-Amram says. "That person may be much more excited about the puzzle and interested in solving it than the person in their living room who has TV, books, their family, and other fun diversions." She adds, "I am not trying to say that zoos are as bad as solitary confinement." But captive hyenas clearly live in a more predictable, less stimulating environment than the Kenyan savannah.

Not all the hyenas learned how to open the box. But scientists learned something that might be critical. When researchers are wondering about the "maximum cognitive abilities" of a species, Benson-Amram says, captive animals may be better subjects. When they want to know what a species is capable of in the wild, though, they should remember that it's a war zone out there.

Benson-Amram, S., Weldele, M., & Holekamp, K. (2012). A comparison of innovative problem-solving abilities between wild and captive spotted hyaenas, Crocuta crocuta Animal Behaviour DOI: 10.1016/j.anbehav.2012.11.003

Image and video courtesy of MSU.

Why Humans Prefer Not to Gallop

As kids, we discover that our two legs can manage many different gaits. After walking and running we figure out how to tiptoe, hop, and skip. (Personally, I decided at one point to become a better skipper than anyone I knew, practicing backward skipping and figure-eights in our driveway. I may have sensed that my competition in this pursuit was not very stiff.)

For basic getting around, we usually settle on walking and running. But why do we ignore so much of our bipedal repertoire in favor of locomotion that's more, well, pedestrian? Researchers in Belgium asked this question about one gait in particular: the gallop.

In case you missed this one as a kid, the human version of a gallop involves holding one leg always in front of the body and the other leg always behind. Bounding along, you create an uneven rhythm of footfalls: ba-DUM, ba-DUM, ba-DUM.

"Gallop is, though rarely used, a familiar gait for humans," the authors write in the Journal of Experimental Biology. People may start galloping spontaneously under certain (infrequent) circumstances, such as going quickly downhill.

For their study, lead author Pieter Fiers of the University of Antwerp and his colleagues had a dozen volunteers run and gallop down a hallway, then dissected their motion in great detail. Platforms that lined the hallway measured the force people produced in their steps. The subjects were covered in motion-capture markers, like Avatar actors. Finally, a separate group of subjects did their running and galloping on a treadmill while the researchers measured how much oxygen they used and carbon dioxide they gave off.

People preferred to gallop at pretty much the same speed they ran. But the length of a galloping stride was shorter than a running stride—so gallopers had to take more steps, and do more work, to travel at the same speed as runners.

Gallopers exerted that effort unevenly, with the front leg doing more work than the back leg. And the galloping stride, researchers saw, demanded more from the hips than running did. This tired people out quickly. Out of 12 treadmill gallopers in the study, 4 gave up before the end of their 4-minute session, complaining of fatigue and stress in their hips and thighs. (An intended 13th galloper couldn't figure out how to gallop on the treadmill belt in the first place.)

When researchers calculated their subjects' metabolic rates, they found that galloping was about 24% more costly than running at the same speed. In other words, galloping burns up more energy, takes more effort, and is less comfortable than running. It's no wonder we don't usually opt for it.

Still, the fact that we're not efficient at galloping means it would be a tougher workout than running. Maybe athletes should start mixing some alternative gaits into their usual exercise routines. Who knows—with practice, you might become the best galloper in the whole world.

Fiers P, De Clercq D, Segers V, & Aerts P (2012). Biomechanics of human bipedal gallop: asymmetry dictates leg functions. The Journal of experimental biology PMID: 23239890

Image: Devon D'Ewart (Flickr)

12 Days of Inkfish, Day 12: Cuddlefish

Sometimes a cuttlefish wants to cuddle, and sometimes it wants to attack you with its face and ingest you whole. Both sides of the cephalopod's personality are on display in this video from the BBC. Also on display: the giant cuttlefish's unbelievable full-body strobe light effect. This is an animal you want to stay on the good side of.

Thanks for celebrating the 12 Days of Inkfish with me! Next week, regularly scheduled programming will return. Stay tuned for new science and new marveling at nature's old—but spectacular—tricks.

Until then, did you miss any of these?

Day 1: What happens when inkfish receive gifts
Day 2: Life as an upside-down jelly
Day 3: Head explosions and a reverse sun
Day 4: The help desk answers "orangutan stop following me" and other reader questions
Day 5: A video of grebes running on water to prove their commitment
Day 6: How Zion Canyon is like the Princess and the Pea
Day 7: Which posts won Best Mustache and other superlatives in the 2012 yearbook
Day 8: This nebula is a square peg in a round universe, thank goodness
Day 9: These airport worms are hard at work eating your garbage
Day 10: Sending you all on an acoustic scavenger hunt (please report back!)
Day 11: The most charming breeds of purse animals

Image: Screenshot from "Animal mating rituals of giant cuttle fish in the blue Australian ocean waters" by BBC Worldwide

12 Days of Inkfish, Day 11: Purse Animals

Ordinarily, I would use "purse animal" to describe one of the low-weight-class dog breeds that city dwellers carry around in designer shoulder bags. In this case, though, the animals aren't inside Louis Vuitton purses—they're made of them.

For the opening of a new London store in 2010, Louis Vuitton commissioned British artist Billie Achilleos to create a series of animal sculptures. The creatures would be made entirely from leather purses and other accessories. With the fashion house's blessing, the artist began hacking up some pricey bags.

The first set of animals went into glass dome jars in a window display in the new store. Having been sufficiently charmed, Louis Vuitton commissioned even more purse creatures the next year for the launch of its bag-monogramming service.

Achilleos wrote on her blog about choosing the materials for each animal carefully. A noisy grasshopper was made from "products with zips and poppers that make satisfying noises." To build the pragmatic beaver, she used men's wallets and bags. 

Scroll through the complete set of purse animals at Louis Vuitton's Facebook album. There's also a making-of video on Billie Achilleos's blog. She created a zoo's worth of creatures, ranging from chameleon to puppy. This kind of purse dog, though, doesn't yap.

Images copyright Patrick Gries 2010, via Facebook.

12 Days of Inkfish, Day 10: Acoustic Scavenger Hunt

On the beach of a tiny Scottish island, a person kicked and jumped through unusual "singing sands" that made a squeaky barking sound in response. More than 3,600 miles away, I was able to eavesdrop on the weird phenomenon because that person had uploaded a recording to the website Sound Around You.

This crowdsourced sound map is a project by researchers at the University of Salford in Manchester. Volunteers around the world have shared ambient noises or noteworthy moments from their environments. The researchers hope to learn about how our soundscapes make us feel, and how they affect our lives.

Exploring the map they've built so far, you can hear street music in Chile, a quiet countryside in Thailand, and chatter on an Italian bus. From Israel, someone has uploaded the wail of an air-raid siren. Once you start cupping your ear toward people and streets on the other side of the world, it's hard to turn away.

The ambient noises of wind and elevated trains in Chicago seem to be pretty well covered already. But if you live someplace with more interesting background noise, you can use a free app called i-SAY to capture (and share) the sounds around you.

Image: Sound Around You

12 Days of Inkfish, Day 9: Airport Worms

While you were vacationing on New Year's Day, nearly two million worms were working hard at Charlotte Douglas International Airport. The airport installed them in the fall of 2012 as part of its new recycling center. By munching through passengers' coffee grounds, used paper towels, and uneaten French fries, the worms are making garden fertilizer out of what used to be landfill fodder.

At the recycling center, employees first sort through the airport's 25 daily tons of trash. Recyclables such as cardboard, aluminum, and plastic are sold. (One airline, project director Bob Lucas said in November, discards entire sleeves of plastic cups even if only a few were used during a flight.) Clothing, which Lucas said panicked passengers dump in the trash when their bags are overweight, is collected by a "group of ladies" who clean and donate it.

As for the worm food itself, it gets heated and pre-composted before finally going to the red wigglers. The airport plans to use waste from the worms to fertilize its grounds. The slimy new employees are happy and—now that Lucas has figured out how to stop them fleeing during a thunderstorm—seem to plan on staying at their jobs.

Image: Sparrows' Friend (via Flickr). Thanks to Leigh for the tip!

12 Days of Inkfish, Day 8: Square Peg in a Round Universe

We can all agree there's too much round stuff in space, right? All those planets and stars and orbital paths and moon craters and disks of debris get old. The most variation you can usually hope for is an astroid shaped like a potato.

Here, for some relief, is the aptly named Red Square nebula. Researchers Peter Tuthill of Sydney University and James Lloyd of Cornell University created this image of the cloud, which surrounds a star called MWC 922.

The researchers think its square shape might be due to a lucky viewing angle on our part. The nebula may really be two cones of gas pointing outward, as if the star at the center were a cheerleader holding a giant megaphone in either hand. From our angle, the nebula looks like a giant X or square. If it turned 90 degrees, we'd find ourselves facing—yet again—some round stuff in space.

Image: Peter Tuthill, Sydney University Physics Dept., Palomar and W.M. Keck observatories (via APOD)