Wired

Powered by nothing more than puffs of air, robots molded from paper and silicone rubber can bend, twist, grip and even lift more than 100 times their weight.

The pneumatic prototypes aren’t as advanced as their metallic brothers, and the “soft” robots contain no electronics yet. But their creators, funded by Darpa, imagine applications where a soft-bot might be the best tool.

“If you want to go through a winding tube or rubble or some other tough environment that’s difficult to reach, you need to be flexible,” said chemist Xin Chen of Boston University, member of a team who describes their work in a Feb. 9 Advanced Functional Materials paper.  “Soft robots can go a lot of places where hard robots cannot go.”

Robots crafted from metal or other hard materials, filled with electronics and powered by electricity are the mainstays of robotics. They can build cars, carry heavy equipment and even defuse bombs. Yet in some environments, flexibility is crucial.

As a result, engineers have looked to nature for ideas, with models inspired by insects, birds, snakes, fish and even dogs. Whitesides and his team have already developed air-powered rubber robots that can constrict like snakes and undulate under obstacles (video below).

Their new work takes the soft robots a step further by incorporating paper, fabric and wire mesh to add strength and definition to silicone-molded shapes. After they’re molded, the devices are hooked up to a simple compressed air source, such as a syringe.

Getting the soft robots to perform a particular action is a feat of origami: Folded in just the right way and glued in the right spots, for example, the researchers showed how a crinkled clump of silicone-soaked paper lifted a 2-pound weight. The force of the air required to drive it was roughly twice that of a human exhalation.

The team has also cylinders that blow into spheres, tubes that act like springs and compact stacks that turn into rigid rings or pipes.

In the future, the researchers hope to add wiring and electronics to bring even more functions to their forms.

The military is interested in such robots as weapons or spying devices, but beyond battlefields the researchers also envision shrinking their creations.

“In principle, you could scale down to microscopic or nanoscopic scales,” Chen said. “You can’t do the same with hard materials.”

Images: Ramses V. Martinez et al./Advanced Functional Materials 1) Glued in the right places (dotted lines) and filled with air, a silicone-soaked piece of paper can take on highly specific shapes. 2) A paper robot bellows lifts 120 times its own weight.

Video: GMWGroupHarvard/YouTube

Citation: “Elastomeric Origami: Programmable Paper-Elastomer Composites as Pneumatic Actuators.” By R. V. Martinez, C. R. Fish, X. Chen and G. M. Whitesides. Advanced Functional Materials. Published online Feb. 9, 2012. DOI: 10.1002/adfm.201202978

The supermassive black hole at the center of our galaxy may be constantly snacking on asteroids. A new study finds that asteroids at least 12 miles wide falling into the black hole would account for the regular bright x-ray flares seen through telescopes.

Though nothing, including light, can escape a black hole, most are ringed by a disk of gas and dust. As it falls in, this material heats up to incredible temperatures, generating energy.

For several years, NASA’s Chandra X-ray Observatory has spotted daily fluctuations in the emissions coming from the Milky Way’s central black hole. Known as Sagittarius A*, this 2-million- to 4-million-solar-mass black hole is approximately 26,000 light-years from Earth near the border of the constellations Sagittarius and Scorpius.

Sagittarius A*’s daily flares generally last a few hours and increase the black hole’s brightness by a hundred times. Scientists have been at a loss to explain why the black hole would have such regular eruptions.

Researchers now suggest that tens of trillions of asteroids and comets, stolen from their parent stars, might float around the black hole. If a 12-mile-wide (or larger) asteroid should get within 100 million miles of the black hole, tidal forces would rip it to shreds. These fragments would then fall in and be vaporized by friction as they encounter the gas and dust churning around the black hole.

The central supermassive black hole could sustain these regular flares for billions of years. Even at a rate of one asteroid per day, it would have only consumed a few trillion asteroids over the lifetime of the galaxy, leaving plenty of fodder.

An unfortunate planet coming loose from its parent star could also get ripped apart in this manner. Because planets are far less numerous than asteroids, this process would be much rarer. Were a planet to be eaten, it would produce a dramatic flare, brightening the black hole by a million times its normal output.

Such an event may have occurred 100 years ago. Chandra and other x-ray telescopes have detected a “light echo” reflecting off nearby clouds that could be evidence for a planetary consumption.

                   runMobileCompatibilityScript('myExperience1441354336001', 'anId'); brightcove.createExperiences();

Image: X-ray: NASA/CXC/MIT/F. Baganoff et al.; Illustrations: NASA/CXC/M.Weiss

Video: An artist’s conception of an asteroid falling into a black hole, producing x-rays. NASA

Scientists have discovered some of the most stretchable spider silk ever, which can elongate up to 7.5 times its initial length. European cave spiders produce the silk to build egg sacs that protect their developing young.

Spider silk is a remarkable material known for its strength and toughness. Most species secrete seven or eight types of silk for different purposes. Dragline silk, for instance, anchors spiders to a surface and is used as the backbone of most webs while other silks are used for web scaffolding or to wrap captured prey.

Female European cave spiders (Meta menardi), which live in dark, humid places ranging from northern Europe to Korea, produce tear-shaped egg sacs that hang from cave ceilings by a short stalk made of tubuliform silk. The fibers are relatively large, with an irregular surface unlike any other type of silk and are coated with a gluey secretion that fastens them together.

In the recent study, researchers collected the egg sacs from different caves in Piedmont, Italy and subjected the stalk silk to a variety of tests. A tensile testing machine pulled on the silk fibers until they broke.

The egg-sac silk of other spider species generally stretches by only 20 to 50 percent before snapping apart. The M. menardi stalks, on the other hand, stretched to two or three times their initial length, with some extraordinary examples drawn out to 7.5 times their initial length. The findings suggest the egg sac stalk is composed of densely and randomly packed fibers that can unroll a great deal in order to stretch.

The work appear Feb. 8 in the journal PLoS ONE.

Images: 1) European Cave Spider with egg sac. Francesco Tomasinelli.

Citation: “Evidence of the most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi.” Emiliano Lepore, Andrea Marchioro, Marco Isaia, Markus J. Buehler, Nicola M. Pugno. PLoS ONE 7(2): e30500. doi:10.1371/journal.pone.0030500

 

It’ll be a geological showdown for the ages, with North America, South America, Europe and Asia colliding head-on over the North Pole to create a supercontinent called Amasia.

Unfortunately, nobody we know will be around to watch the collision, which won’t happen for another 50 million years or more. But it’s still fun to imagine.

“The snapshot that is the present is smack-dab in the middle of what we call the supercontinent cycles,” said geologist Ross Mitchell of Yale University, lead author of a Feb. 8 Nature prediction of supercontinental trajectories. “We’re part of something larger, both in the past and into the future.”

Mitchell’s group isn’t the first to say that Amasia will form, but geologists differ on where exactly this will happen.

Some think that supercontinents break up, drift apart, and gather again in the same place. They say Amasia will swallow the Atlantic and center itself over present-day Africa, at the heart of Pangea, the last supercontinent, which broke up 250 million years ago.

Other geologists believe supercontinents break up, drift apart, and gather again on the other side of Earth. This would place Amasia somewhere between Hawaii and Fiji, and swallow the Pacific.

Mitchell’s group, however, places Amasia in the Arctic. Their conclusion is based on records of Earth’s magnetic field as contained in rocks dating back 800 million years to Rodinia, the supercontinent that preceded Pangea.

According to their interpretation, the geomagnetic record only makes sense if supercontinents rotate on their axes at a 90 degree angle, which would send Amasia into an unexpected polar location.

Given that their data spans 800 million years yet contains only 2 examples of supercontinental rotation, this will be a hard hypothesis to test. Whether or not it holds up, however, the research should illuminate a question even more fundamental than where supercontinents will gather.

“One of the larger questions in research is, ‘Why does a supercontinent even break apart?’” said Mitchell.

                   runMobileCompatibilityScript('myExperience1441125743001', 'anId'); brightcove.createExperiences();

Image: At left, the current arrangement of the continents; at right, their proposed arrangement in 100 million years. (Mitchell et al./Nature) Video: The last 500 million years of Earth’s continental drift. (Mitchell et al./Nature)

Citation: “Supercontinent cycles and the calculation of absolute palaeolongitude in deep time.” By Ross N. Mitchell, Taylor M. Kilian & David A. D. Evans. Nature, Vol. 482, No. 7384, 9 February 2012.

By Kate McAlpine, ScienceNOW

Think floating pyramids are more metaphysics than physics? Think again. Results just in from an experiment that levitated open-bottomed paper pyramids on gusts of air reveal a curious phenomenon: When it comes to drifting through the air, top-heavy designs are more stable than bottom-heavy ones. The finding may lead to robots that fly not like insects or birds but like jellyfish.

Physicist Jun Zhang and his colleagues at New York University wanted to better understand how flying bugs control the orientations of their bodies. Do they have to work at it, or are they naturally stable? Robotics isn’t yet to the point at which machines with flapping wings are easy to make, so Zhang’s team chose to simulate the effect of flapping wings by creating stationary fliers floating on moving air. They used a subwoofer to oscillate the air inside a cylinder, “acting like a wind tunnel with air moving up and down,” Zhang explains. At 10 to 50 beats per second, the tempo corresponds to wing-flapping at hummingbird speed.

The researchers placed hollow paper pyramids inside the cylinder. The objects were about 1 to 5 centimeters high and were made of tissue paper or letter paper on carbon fiber supports, like tiny homemade kites. Physicist Bin Liu led the experiments, attaching a beadlike weight to a post running down the center of the pyramid and changing the height of the bead to give the object a different center of mass. Common sense says that the pyramid should be most stable when the bead is at the bottom of the post, like ballast in the hold of a ship. But when the team released the pyramids over the subwoofer, the opposite was true: The bottom-heavy pyramids were likely to flip over and fall, whereas the top-heavy ones remained upright and continued to hover (see first video), the group reports in an upcoming issue of Physical Review Letters.

brightcove.createExperiences();

A pyramid with a low-hanging weight can’t right itself; it remains tilted and falls. A top-heavy pyramid quickly straightens out and continues to hover. (Leif Ristroph)

The team suspected that the effect was due to swirls of air that develop along the pyramid’s sides. To see the swirls in action, Zhang’s group examined a two-dimensional version of the pyramid experiment in water. They placed upside-down V shapes into a pan of water and rocked it to create currents. As the water ran past the V, it created tiny whirlpools at the ends of the V’s two legs (see second video). These swirls pushed away from the upside-down V, moving downward, which exerted an upward force on the V-the same mechanism that creates lift in the pyramids.

If the V was tilted, however, the swirls went in different directions: Those on the higher leg shoved it sideways, while the lower leg got a weaker upward push. This would straighten the upside-down V. Team member Leif Ristroph showed that the same sorts of swirls roll off the sides of the pyramids: They push the pyramid upright as long as the center of mass is above the tilted-up side, much in the same way that you can balance a vertical stick on the end of your finger by moving the bottom of the stick in the direction of the tilt, Zhang says. For bottom-heavy pyramids, this same mechanism causes them to flip over — it’s like moving the top of the stick in the direction of the tilt, encouraging it to fall.

brightcove.createExperiences();

Tiny whirlpools appear as shadows at the ends of the V, generated by the water flowing up and down. If the V is level, the swirls go downward, exerting an upward push on the V, but if the V is tilted, the swirls go in different directions, and their combined push could straighten the V out. (Bin Liu)

Robotics engineer Hod Lipson of Cornell University suggests that he may have already seen the stability mechanism at work in flapping, flying robots made in his own lab. “[This result] opens up new, unexplored design opportunities,” he says.

In particular, Zhang’s team suggests that flapping pyramid or cone robots could combine stability and maneuverability. They would quickly right themselves if they leaned further than 30° in any direction, but within 30°, they should move freely. Although the robots wouldn’t be like any insect known to entomologists, the flapping cones would have living analogs in the sea. Computational scientist Petros Koumoutsakos of the Swiss Federal Institute of Technology in Zurich, whose team made a computer model of a swimming jellyfish in 2009, says that jellyfish create swirls of water similar to the swirls of air that balance the pyramids.

“The team proposes a very unique and interesting approach,” says Hao Liu, a biomechanical engineer at Chiba University in Japan. He awaits experiments to show that flapping pyramids and cones can stay aloft.

This story provided by ScienceNOW, the daily online news service of the journal Science.

Image: This subwoofer plays a constant beat that pumps the air up and down inside the wind tunnel. The diffusers allow air to flow without turbulence so that the paper pyramid floats inside. (Bin Liu)

By Mark Brown, Wired UK

The Philippine tarsier is a tiny primate with a seriously high voice. The saucer-eyed mammal can let out (and listen to) squeaks and squeals at such a high frequency that it effectively gives the mammal a private communication channel.

A team of researchers, led by Marissa Ramsier of Humboldt State University in California, found that the tiny tarsier can hear and emit sounds in the ultrasound range — that’s above 20 kHz.

Most humans can’t hear in that range, and a dog whistle is pitched to be just inside ultrasound, somewhere between 22 and 23 kHz. A handful of mammals can make sounds in this range — some whales, domestic cats and a few species of bats — but few can match the Philippine tarsier.

When issuing warnings or ferreting out crickets for a nighttime snack, the nocturnal faunivores (that’s a mix of carnivore and insectivore) can vocalize in a range around 70 kHz, and pick up frequencies above 90 kHz.

“Such values are among the highest recorded for any terrestrial mammal,” the researchers note in their paper, which was published in Biology Letters.

To get this reading, they captured six of the docile creatures and placed them inside custom-built sound chambers to test their sensitivity to high-pitched sounds. Then, they recorded another 35 specimens in the wild to measure the frequency of the tarsier’s chatter.

In the paper, the researchers explain that, “ultrasonic alarm calls can be advantageous to both the signaller and receiver as they are potentially difficult for predators to detect and localise.” Being able to hear in high ranges might let them eavesdrop on noises made by moths, crickets and birds.

Image: Roberto Verzo/Flickr

Source: Wired.co.uk

Astronomers have combined hundreds of images to provide the most detailed view ever of the Carina Nebula, a stellar nursery located about 7,500 light-years from Earth.

The nebula spreads across 150 light-years and shelters some of the brightest and most massive stars known.

The new view covers a patch of sky nearly the size of two full moons, and it reveals hundreds of thousands of once dust-obscured stars, some of which are 10 times less massive than the sun.

Astronomers knew these smaller and fainter stars lurked among the giants, but previous images of the nebula in visible light (right) and infrared light — a wavelength that sneaks through clouds of gas and dust from which stars form — never offered the extreme detail available in the new image (above).

Researchers have used the unprecedented view to identify all-new star clusters and confirm that star formation happens mostly on the borders of giant globules of gas and dust, rather than deep inside of them.

The results, published May 2011 in Astronomy & Astrophysics, also hint that stars tens or hundreds of times larger than the sun are the main driving force behind star formation in Carina. Such mammoth stars can explode into supernovas, spew powerful stellar winds and generate other means of compressing free-floating gas and dust into nascent stars.

To capture faint stars glowing alongside these giants, astronomers used an infrared camera called HAWK-I at Europe’s Very Large Telescope, a four-telescope array situated in Chile’s high-altitude Atacama Desert.

Images: ESO/T. Preibisch [high-resolution and sliding image comparison]

Video: ESO/Nick Risinger (skysurvey.org)/Digitized Sky Survey 2/T. Preibisch

Citation: “Deep wide-field near-infrared survey of the Carina Nebula.” By T. Preibisch, T. Ratzka, B. Kuderna, H. Ohlendorf, R. R. King, S. Hodgkin, M. Irwin, J. R. Lewis, M. J. McCaughrean and H. Zinnecker. Astronomy & Astrophysics, published online May 4, 2011. DOI: 10.1051/0004-6361/201116781

<< Previous | Next >>                     runMobileCompatibilityScript('myExperience1432168167001', 'anId'); brightcove.createExperiences();

Microscope photography can take us places we couldn't otherwise go, places we didn't even know existed. But microscope video can bring those places to life.

Every year, Nikon holds a photomicrography contest that honors some of the best microscope images you'll ever see. This year, they've added video with their Nikon Small World in Motion competition. The best of more than 200 videos show amazing microscopic activity, including cells dividing, ants feasting and asexual yeast budding.

The winning video (above) uses an injection of ink into a 72-hour-old chick embryo to illustrate the blood system. Watch the 2nd and 3rd place videos, along with 11 honorable mentions in this gallery.

1st Place: Chick Ink Injection Into Blood Vessels

Anna Franz, Oriel College, Dunn School of Pathology, UK

Technique: Reflected light microscopy

Magnification: 10x

Ink injection into yolk sac artery of 72-hour-old chick embryo to visualize the beating heart and the vasculature.

<< Previous | Next >>View all

Videos courtesy of Nikon Small World

<< Previous | Next >>

<< Previous | Next >>View all

Nature is supposed to be red in tooth and claw, and domestication an artificial process for making animals gentle. But it appears that some corners of the animal kingdom are becoming kinder, gentler places. Certain creatures may be domesticating themselves.

This possibility is most apparent in bonobos, a close cousin of chimpanzees. Unlike their violent cousins, bonobos are generally peaceful. And while many animals have evolved to be socially agreeable, bonobos — and possibly other species — seem to be experiencing something more precise and profound: the physical and behavioral changes specifically described in studies of domestication, but as a natural evolutionary process.

“Normally you think of domestication as something that happens at the hands of humans,” said Brian Hare, a Duke University evolutionary anthropologist and co-author of a bonobo research review published Jan. 20 in Animal Behaviour. “The idea that a species domesticated itself is a bit crazy, but there are some species that outcompeted others by becoming nicer.”

The essence of domestication is a loss of aggression. Because this is such a basic trait, involving modifications to nervous and endocrine systems, and alterations of complex gene networks with multiple functions, it generates a variety of changes. Researchers call them a “domestication syndrome,” and while aspects are seen in all domesticated animals, the principles are distilled in a famous Russian experiment on foxes.

Starting in 1959 with 130 farm-bred but wild foxes and continuing until today, researchers allowed only those individuals most tolerant of human contact to breed. In less than 50 years, the fierce-tempered and untouchable foxes became playful, face-licking sweethearts who loved to be held. Those traits are typically seen in wild pups, but disappear as they grow up.

With juvenile behaviors came juvenile appearances: Even as adults, foxes in the experiment now have spotted coats, floppy ears, curly tails and short legs. They’re evolutionarily suspended in childhood — and that, said Hare, may explain bonobos. “I have a lot of bonobos who are ‘friends,’ and I look at them and say, ‘I don’t understand how you evolved. You are too goofy, too nice, too silly. How did you not get eaten?” he said. “But they are very successful.”

"I have a lot of bonobos who are 'friends,' and I look at them and say, 'I don't understand how you evolved. You are too goofy,'" said Hare. Photo: Pelican/Flickr

Bonobos are very different than chimpanzees, from whom they split taxonomically about one million years ago. Chimp males struggle constantly and violently for dominance; bonobo males almost never fight, and stage virility contests involving non-confrontational stick-dragging. Male chimps often coerce females into sex; bonobos ask for permission. At the group level, chimpanzees regularly engage in something like low-level warfare, with lethal consequences; bonobos don’t. Mostly they hang out, play, and exchange sexual favors with frequency so astounding they’ve become pop-culture tropes.

Lab tests back up in-the-wild observations. Relative to chimps, bonobos are stressed by competition, attentive to others’ needs, and eager to cooperate and share. Brain regions crucial to behavior and development, like the amygdala and occipital frontal cortex, are arranged differently. And in keeping with theories of domestication, bonobos play like juvenile chimpanzees, but throughout their lives. Their skulls also have smaller jawbones and teeth, or what anatomists call “paedomorphic” — child-shaped — features. They also have a white tail tuft and extra-pink lips, a possible analogue to the white spots often seen in, for example, cats and dogs.

According to Hare and study co-author Richard Wrangham, one of the world’s foremost primatologists, these are likely signs of domestication. But why and how could natural selection tame the bonobo? One possible narrative begins about 2.5 million years ago, when the last common ancestor of bonobos and chimpanzees lived both north and south of the Zaire River, as did gorillas, their ecological rivals. A massive drought drove gorillas from the south, and they never returned. That last common ancestor suddenly had the southern jungles to themselves.

As a result, competition for resources wouldn’t be as fierce as before. Aggression, such a costly habit, wouldn’t have been so necessary. And whereas a resource-limited environment likely made female alliances rare, as they are in modern chimpanzees, reduced competition would have allowed females to become friends. No longer would males intimidate them and force them into sex. Once reproduction was no longer traumatic, they could afford to be fertile more often, which in turn reduced competition between males.

“If females don’t let you beat them up, why should a male bonobo try to be dominant over all the other males?” said Hare. “In male chimps, it’s very costly to be on top. Often in primate hierarchies, you don’t stay on top very long. Everyone is gunning for you. You’re getting in a lot of fights. If you don’t have to do that, it’s better for everybody.” Chimpanzees had been caught in what Hare called “this terrible cycle, and bonobos have been able to break this cycle.” In doing so, they rose to primate supremacy in a region roughly the size of the United States east of the Mississippi River, and reigned unchallenged until Homo sapiens came along.

All this, at least, is the hypothesis: It’s important to note that it’s a proposed rather than certain scenario. It’s at least conceivable, if highly unlikely, that bonobos started out peaceful and chimpanzees became more aggressive. Conclusive proof would require a time machine. Still, the evidence is suggestive and the scenario plausible.

'The idea that a species domesticated itself is a bit crazy, but there are some species that outcompeted others by becoming nicer.'“High aggression is likely costly,” said Frank Albert, an evolutionary anthropologist at Princeton University who studies the genetics of domestication. “So it seems not very surprising that some of the bonobo-chimp ancestors may have benefited from evolving reduced aggression — and eventually become today’s bonobos.”

Not that bonobos will soon be peeking out of cardboard boxes on Cute Overload. On the trajectory from wild to domestic, they’re something like certain wolves were tens of thousands of years ago, after reduced aggression allowed them to exploit a new ecological niche at the edges of growing human settlements, said Hare. At that time, people hadn’t yet started keeping and breeding dogs. Once they did, it accelerated a domestication already naturally underway.

But why stop with dogs and bonobos? Hare and Wrangham suspect self-domestication is happening elsewhere, and new niches around human habitation remain a likely place look. Large cities and suburbs are new to much of Earth’s surface, and represent opportunity to animals that can exploit them. A lack of aggression isn’t absolutely necessary — learning to hide quietly in brush by a sidewalk can represent wariness, not amiability — but it could help.

“I live in Chapel Hill, North Carolina, and we’re overrun by deer. I keep seeing deer in my neighborhood with the star mutation,” said Hare, referencing the Bambi-style spotting traditionally seen in young deer and domesticated animals. “I’d love to know whether, if you did a study where there’s no urbanization, would you see a lower rate of the star mutation?” One study of Florida Keys deer, an endangered subspecies of white-tailed deer, didn’t look at pigmentation, but did find that urbanized deer were less fearful and lived in larger groups than before.

(If it seems like such significant evolution shouldn’t happen so quickly, remember that many changes underlying the domestication syndrome don’t involve mutations to genes, but so-called epigenetic changes in the timing of gene activity. Epigenetics allows change to occur more rapidly than is possible through genetic mutation alone. “Evolution can happen very fast. It’s happening now,” Hare said.)

Another possible example is the Tonkean macaque, which is less aggressive than any other macaque species. They live in cohesive social groups and fight rarely. Unlike other macaques, their conflicts are followed by acts of reconciliation. They also have a habit of baring their teeth, but whereas in other macaques it signals submission, in Tonkeans it’s exchanged between equals. “This display is used like a smile,” said ethologist Bernard Thierry of the University of Strasbourg.

Thierry has tried to understand why Tonkean macaques are so exceptionally agreeable. It’s almost certainly the result of some evolutionary pressure, and that pressure could be self-domestication, though it hasn’t yet been demonstrated. “We still don’t know why some are nicer than others,” he said.

Self-domestication may also be favored on islands, where limited space and high population densities turn territorial defense into a constant fight. In such circumstances, aggression becomes self-destructive. “At very high densities, it becomes impossible to defend anything,” said Judy Stamps, the University of California, Davis evolutionary ecologist who studied how behaviors change on islands. “In that situation, the animals might as well just relax. Instead of competing aggressively, animals might begin to cooperate with each other.”

That seems to be happening in Panamanian island populations of Central American spiny rats, which are significantly less aggressive than their mainland brethren. Hare even wonders if historical tales of island animals treating the first human arrivals without fear reflect not inexperience, but possible self-domestication.

Finally, Hare has one more candidate for self-domestication: Homo sapiens. At some point in our prehistory, we became much less aggressive and much more social. Some researchers link this to domestication-like changes in our biology. It’s impossible to say for sure, and sociobiological origin stories — special diets, tool use, hunting, symbolism — are legion. But perhaps it’s time for one more. Maybe, just maybe, somewhere along the line, we simply got nicer.

Bonobo images: 1) A bonobo group hug. (LaggedOnUser/Flickr) 2) Bonobo and infant. (Pelican/Flickr)

Fossils of A. musicus wings and illustrations of its wing ridges. Images: Gu et al./PNAS

A cricket song last heard 165 million years ago has been played again.

To reconstruct the sound, paleontologists compared microscopic wing structures of fossil Archaboilus musicus, a Jurassic ancestor of modern crickets, to contemporary wings. Crickets sing — or, technically, “stridulate” — by rubbing together the ridged edges of their wings.

From noises generated by modern features, the researchers could extrapolate what A. musicus sounded like. (To listen, play the file below.) Theirs was a powerful song, almost certainly used to attract mates.

“The low-frequency musical song of A. musicus was well-adapted to communication in the lightly cluttered environment of the mid-Jurassic forest produced by coniferous trees and giant ferns,” wrote the researchers, led by Jun-Jie Gu of China’s Capital Normal University, in a Feb. 7 Proceedings of the National Academy of Sciences paper. “Reptilian, amphibian, and mammalian insectivores could have also heard A. musicus’ song.”

What does the song tell us? To the researchers, it suggests that cricket songs are ancient, rather than a recent evolutionary innovation, and hints at the sonic richness of the Jurassic world.

The cricket’s song is not, however, the oldest noise in the world. That honor goes to the sound of our universe’s birth.

Image & audio: 1) The fossil wings of A. musicus. (Gu et al./PNAS) 2) The sound of A. musicus. (Gu et al./PNAS)

Image: NASA/NOAA

In recent weeks, a pair of high-resolution images of the Earth has captivated the public. Taken by the Suomi NPP satellite, these pictures portray our planet’s incredible beauty with 8,000- by 8,000-pixel and 11,500- by 11,500-pixel detail.

How were these highly detailed images created? The satellite flies 512 miles above the Earth, but the images appear as if they were taken from a much higher perspective: an altitude of 1,242 for the first image and 7,918 miles for the second. This little trick was accomplished by stitching together data from several orbits, creating an image that appears to be “pulled back.”

NASA launched the 4,600-pound Suomi in October to remotely sense variations in the Earth’s oceans, continents, and atmosphere and get a better understanding of climate change. It passes directly from pole to pole 14 times a day, imaging 1,865-mile swaths of our planet with each trip.

On board Suomi, the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument takes pictures in red, green, and blue wavelengths. For the whole-Earth images, those wavelengths were combined to create a natural color photograph. It is not an exact representation of what an observer sitting in space would see, because particles in the atmosphere scatter short wavelengths of light, and our planet would actually appear more blue-tinged. The photos more accurately portray how the oceans and continents appear from the ground.

Oceanographer Norman Kuring, who compiled the two pictures, said the original image, showing North and Central America, was made as a favor to project scientist James Gleason who was looking for an ocean color image to show in a presentation. Word got out of the striking picture and NASA officials released it on Jan. 25, resulting in 3 million people viewing it in one week.

With the popularity of this first image and requests from the public for another perspective, the agency produced a second image on Feb. 3 showing Africa and the Arabian Peninsula.

The photos follow in the footsteps of NASA’s other great Earth images. The original Blue Marble — one of the most famous pictures of all time — was captured by the crew of Apollo 17 from a distance of 28,000 miles. Since 2002, the agency has stitched together up to 10,000 satellite images to produce other incredible detailed images. One of the most recent, from 2007, had a mind-boggling resolution of 86,400 pixels by 43,200 pixels.

Such pictures have proved time and time again to be among the most-viewed and best-loved NASA photos. What accounts for their enduring popularity?

“My guess is that people know that this is the only place we have to live. When they see an image showing these beautiful blues and greens, it speaks to them,” said Kuring. “This is our home.”

Update: Russian news agency Ria Novosti has reported that the team penetrated Lake Vostok on Feb. 5, 2012. According to the report, the researchers stopped drilling at a depth of 3,768 meters as they reached the surface of the sub-glacial lake.

After 20 years of drilling, a team of Russian researchers is close to breaching the prehistoric Lake Vostok, which has been trapped deep beneath Antarctica for the last 14 million years.

Vostok is the largest in a sub-glacial web of more than 200 lakes that are hidden 4 kilometers beneath the ice. Some of the lakes formed when the continent was much warmer and still connected to Australia.

The lakes are rich in oxygen (making them oligotrophic), with levels of the element some 50 times higher than what would be found in your typical freshwater lake. The high gas concentration is thought to be because of the enormous weight and pressure of the continental ice cap.

If life exists in Vostok, it will have to be an extremophile — a life form that has adapted to survive in extreme environments. The organism would have to withstand high pressure, constant cold, low nutrient input, high oxygen concentration and an absence of sunlight.

The conditions in Lake Vostok are thought to be similar to the conditions on Jupiter’s moon Europa and Saturn’s tiny moon Enceladus. In June, NASA probe Cassini found the best evidence yet for a massive saltwater reservoir beneath the icy surface of Enceladus. This all means that finding life in the inhospitable depths of Vostok would strengthen the case for life in the outer solar system.

Back on planet Earth, the team at Vostok are running short on time. Antarctica’s summer will soon end and the researchers need to leave their remote base while they still can. Temperatures will drop as low as -80 degrees Celsius, grounding planes and trapping the team.

They missed their chance last year. “Time is short, however. It’s possible that the drillers won’t be able to reach the water before the end of the current Antarctic summer, and they’ll need to wait another year before the process can continue,” we wrote in January 2011. The drill halted in February.

Meanwhile, Russian engineers are planning to venture into the lake itself, with swimming robots. In the Antarctic summer of 2012 to 2013, they plan to send a robot into the lake to collect water samples and sediments from the bottom. An environmental assessment of the plan will be submitted at the Antarctic Treaty’s consultative meeting in May 2012.

Image: NSF

Source: Wired.co.uk

A controversial proposal would regulate sugar as a toxic substance, and not simply because it’s a calorie-rich enabler of obesity. Some researchers say it’s intrinsically dangerous, not unlike alcohol or tobacco, with unique properties that set off a hormonal cascade ending in higher risks of heart disease, stroke and type 2 diabetes.

It’s not a scientifically certain proposition, though a growing body of research suggests it may very well be true, and the implications are thorny. Even people sympathetic to public health-based regulations may balk at treating pastries as cigarettes, as University of California, San Francisco nutritionists suggested in a Feb. 2 Nature paper.

But to anyone looking to artificial sweeteners as an alternative, as pastel-packaged reassurances that regulators won’t ever need to pry donuts from their cold, dead and pudgy hands, science offers only more uncertainty. Some studies even suggest that fake sugar may cause the same problems as real sugar.

“That’s the $64,000 question,” said Susan Swithers of the Ingestive Behavior Research Center at Purdue University. “There are several epidemiological studies showing increased risk of metabolic syndrome in coincidence with the consumption of diet sodas” — a rich source of sweeteners. “But how they should be interpreted is not really clear right now. Because they’re correlational studies, they don’t tell us what caused what.”

Artificial sweeteners are a fast-growing, multi-billion dollar product, present in thousands of foodstuffs and synthesized by chemists as zealously as drug researchers pursue blockbuster drugs. But as described in a massive 2008 American Journal of Clinical Nutrition Review, the seemingly obvious health benefits expected of low-calorie sugar replacements have failed to materialize.

Even as Americans consumed more sweeteners, waistlines continued to expand. Cause and effect was ambiguous: Sweeteners might lead to weight gain, but maybe people most prone to gaining weight consume the most sweeteners. “This association may be coincidental or causal, and either mode of directionality is plausible,” concluded that study’s authors.

'Artificial sweetener use might be fueling -- rather than fighting -- our escalating obesity epidemic.'Other researchers, however, are more suspicious. When University of Texas Health Science Center epidemiologists conducted a 9-year-long study of 5,158 adult residents of San Antonio, Texas, they found a link between sweeteners and obesity. It persisted even after statistically accounting for gender, ethnicity, diet and beginning-of-diet body mass index. “These findings raise the question whether artificial sweetener use might be fueling — rather than fighting — our escalating obesity epidemic,” they wrote.

Another study of 6,184 adult Americans linked diet soda consumption with higher rates of metabolic syndrome, the umbrella term for a physiological disruption that leads to heart disease, stroke and type 2 diabetes. Once again, the link survived statistical adjustment for demographics, lifestyle and diet.

That’s precisely what’s expected from eating too much sugar, which at least in rats is converted in the liver to fat. That in turn provokes, via as-yet-unidentified mechanisms, resistance to insulin, a hormone used by cells to process glucose, better known as blood sugar. When insulin’s signals are ignored, blood sugar levels rise. Metabolic syndrome follows. But why should this happen when eating fake sugar, not real?

Swithers thinks she knows. In 2008, she and fellow Purdue researcher Terry Davidson fed rats a yogurt supplement sweetened either with glucose, a simple sugar, or zero-calorie saccharin. Apart from the supplement, both groups ate standard rat fare. Those that ate saccharin packed on more fat, gained more weight and consumed extra calories. A follow-up 2009 study reinforced the findings, and found that unusual weight gain persisted even when rats stopped eating sweeteners.

According to Swithers, two mechanisms may be responsible. When the rats’ bodies learned that sweetness didn’t predict an imminent caloric rush, as would naturally be produced by sugar-rich foods, their bodies may have automatically shifted into calorie-saving mode. At the same time, metabolic acceleration that normally occurs when eating high-calorie foods, and helps to process them, may have been slowed.

“All of our work has been in rats. We think similar processes happen in humans, but we haven’t tested them,” Swithers said.

Image: Steve Snodgrass/Flickr

<< Previous | Next >>

Photos like this could pass for a Cold War-era Russian propaganda program, or perhaps shots straight from the set of the movie Moonraker — if not for a stray pair of late-20th century sneakers.

Arthur Elgort. (Image: Toby Shaw)

Renowned fashion photographer Arthur Elgort, now 72, actually created these images for the December 1999 issue of Russian Vogue. (The magazine is owned by Conde Nast, which also owns Wired.)

In the images, supermodel Natalia Semanova mingles with real-life cosmonauts at Star City, a town northeast of Moscow and home of the Yuri Gagarin Cosmonaut Training Center, where for more than 50 years the Russian Federal Space Agency has trained willing citizens to fly in space. (Recently they’ve also been trained to survive 520 days inside a tin can.)

The photos experienced a recent resurgence in social media circles, so Wired tracked down Elgort to learn more about the timeless photos.

Wired: What led you to merge the worlds of fashion, science and technology for this shoot?

Arthur Elgort: I find it more interesting to put fashion in a setting that is different. Anywhere that the story can be about places that enhance the clothes.

<< Previous | Next >>View all

All images by Arthur Elgort and used with permission from Russian Vogue

                     runMobileCompatibilityScript('myExperience1431905798001', 'anId'); brightcove.createExperiences();

The European Space Agency’s Rosetta spacecraft is heading for a comet.

The ambitious mission — scheduled to enter orbit around Comet 67P/Churyumov-Gerasimenko in January of 2014 and place a tiny lander named Philae on its surface the following November — will no doubt return incredible, never-before-seen pictures. Until then, observers on Earth will have to make do with artists’ renderings like the ones in this video.

In past decades, about a dozen probes have performed comet flybys, sending back photographs of their nuclei. In 2005, NASA’s Deep Impact spacecraft shot a projectile that hit comet Temple 1.

But Rosetta and Philae will be the first mission to enter orbit around a comet and attempt a controlled landing onto its surface. The comet’s gravity is weak and its surface uneven, so Philae will shoot harpoons into the ground to help anchor it.

The probe will get to watch as the icy comet comes to life. Currently just a frozen ball of ice and dust, Churyumov-Gerasimenko will soon feel heat from the solar wind. Eventually, this radiation will melt the comet’s surface, generating a spectacular tail for Rosetta to observe.

The mission is named after the famed Rosetta stone, which allowed archeologists to decipher ancient Egyptian hieroglyphics. Since comets are frozen remnants from our solar system’s formation, researchers hope that the probe will help them understand how the planets came to be.

Image: Astrium - E. Viktor/ESA

Video: NASA

By Mark Brown, Wired UK

Last week, NASA released its 2012 version of the famous “Blue Marble” image. By using a planet-pointing satellite, Suomi NPP, the space agency created an extremely high-resolution photograph of our watery world.

The photo centered on the western hemisphere, highlighting North and Central America. It went viral and got even more hits on Flickr than the iconic “Situation Room” photo, taken at the time of the assassination of Osama bin Laden.

Now, responding to public demand, the agency has created a companion image: this time focusing its lens toward the East and showing Africa, Saudi Arabia and India.

The Suomi NPP satellite hugs the Earth too closely to get this kind of image in one shot. It’s in a polar orbit with an altitude of 824 kilometers, but the perspective of the Eastern hemisphere Blue Marble is from 12,743 kilometers away.

As such, Nasa Goddard oceanographer Norman Kuring used images from six different orbits of the satellite over an eight-hour time period on Jan. 23, then stitched the photos together to achieve the final composite.

Both of the 2012 Blue Marble images are taken by a new instrument aboard Suomi NPP called the Visible Infrared Imaging Radiometer Suite (VIIRS). As for those four vertical lines: That’s the reflection of sunlight off the ocean, or “glint,” that VIIRS captured as it orbited the globe.

Other famous photos of Earth include the original Blue Marble, which was taken on Dec. 7, 1972, by the crew of the Apollo 17 spacecraft. There’s also the equally famous 2002 one, which you might recognize as the default lock screen on the first iPhone. Plus “You Are Here,” an arresting photo of Earth from the surface of Mars, snapped by the Spirit rover in 2004.

Image: NASA/NOAA [high-resolution]

Source: Wired.co.uk

<< Previous | Next >>

Toxic barbs on a cucumber’s skin, nanoscopic flakes of metal and a mouse’s technicolor eyeball (above) are just a few of 2011′s top science visualizations.

A panel of judges picked the best of more than 200 entries from 33 countries for the 2011 International Science and Engineering Visualization Challenge.

“I think because information technology tools and visualization tools have advanced, people have found ever-increasingly clever ways to display difficult scientific concepts,” said competition judge Thomas Wagner, a cryosphere scientist at NASA, in an interview provided by the contest.

Contest judges made their picks based on visual impact, originality and clarity. The winners, which include “people’s choice” awards as well as honorable mentions, were published online Feb. 2 in the journal Science.

The entries weren’t just limited to photographs. Contest categories also included illustrations, informational graphics, videos and even interactive video games.

See the best of these science and engineering visualizations in this gallery.

Images and videos courtesy of AAAS/Science

Above:

Mouse Eyeball Cells

Researchers stained ultra-thin slices of a mouse’s eye to create this first-place photography winner.

The stain was made of three antibodies that bind to three different molecules present in all cells, but in differing concentrations. Assigning red, blue and green to each antibody allowed the creators to depict more than 70 different cell types in the organ.

Image: Bryan William Jones/University of Utah/Moran Eye Center [high-resolution]

<< Previous | Next >> View all

By Mark Brown, Wired UK

After 20 years of drilling, a team of Russian researchers is close to breaching the prehistoric Lake Vostok, which has been trapped deep beneath Antarctica for the last 14 million years.

Vostok is the largest in a sub-glacial web of more than 200 lakes that are hidden 4 km beneath the ice. Some of the lakes formed when the continent was much warmer and still connected to Australia.

The lakes are rich in oxygen (making them oligotrophic), with levels of the element some 50 times higher than what would be found in your typical freshwater lake. The high gas concentration is thought to be because of the enormous weight and pressure of the continental ice cap.

If life exists in Vostok, it will have to be an extremophile — a life form that has adapted to survive in extreme environments. The organism would have to withstand high pressure, constant cold, low nutrient input, high oxygen concentration and an absence of sunlight.

The conditions in Lake Vostok are thought to be similar to the conditions on Jupiter’s moon Europa and Saturn’s tiny moon Enceladus. In June, NASA probe Cassini found the best evidence yet for a massive saltwater reservoir beneath the icy surface of Enceladus. This all means that finding life in the inhospitable depths of Vostok would strengthen the case for life in the outer solar system.

Back on planet Earth, the team at Vostok are running short on time. Antarctica’s summer will soon end and the researchers need to leave their remote base while they still can. Temperatures will drop as low as -80C, grounding planes and trapping the team.

They missed their chance last year. “Time is short, however. It’s possible that the drillers won’t be able to reach the water before the end of the current Antarctic summer, and they’ll need to wait another year before the process can continue,” we wrote in January 2011. The drill halted in February.

Meanwhile, Russian engineers are planning to venture into the lake itself, with swimming robots. In the Antarctic summer of 2012 to 2013, they plan to send a robot into the lake to collect water samples and sediments from the bottom. An environmental assessment of the plan will be submitted at the Antarctic Treaty’s consultative meeting in May 2012.

Image: Wikipedia/NASA

Source: Wired.co.uk

A view across the Santorini caldera. The newest eruptions in the caldera can be seen on the right on Nea Kameni.

This appears to be a week of media interest in new journal articles. Earlier, I discussed a study that claimed that volcanoes were the cause of the onset of the Little Ice Age. Now, we have a study in Nature that discusses the magmatic events that lead up to the Minoan eruption at Santorini – a fairly timely topic considering the rumblings there – that has gotten the media’s attention.

Now, I’m not going to pick apart this paper by Timothy Druitt and others as such – the study, called “Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano“, is actually quite solid. The long-and-short of the study is that they examined plagioclase feldspar crystals looking at the zoning of different elements in these crystals (see below).

There are two main pieces to the study. First, if a crystal grows in a certain magma, it will suck in certain amounts of different elements – some are major constituents of the minerals. In plagiolclase feldspar, we can define the “An” of a crystal by looking at proportions of Ca and Na in the crystal (high “An” means high Ca – closer to the perfect feldspar endmember anorthosite). The “An” can then tell us if a crystal came from one type of magma or another (see figure below). If there are low abundance elements in the mineral, like strontium, magnesium and titanium in plagioclase feldspar, then the amount of the element is controlled by the partitioning of the element between the liquid magma (melt) and the crystal. This is what geologists call the “partition coefficient” – or how likely is an element to want to be in the crystal or melt. The partition coefficient will change depending on the overall composition, pressure and temperature of the magma and crystal, so crystals in different magmas will suck up different amounts of these elements. This gives them distinctive compositions depending on the magma in which they grew – a “compositional signature” so to speak. (Note: I looked that is in zircon from the Okataina Caldera in my Earth and Planetary Science Letters study from last year).

Part of Figure 1 from Druitt et al. (2012) that shows the zoning of plagioclase feldspar from the Minoan eruption of Santorini.

The second piece is diffusion. Elements in crystals will diffuse back into the melt (or vice versa) if there is a large compositional gradient between the crystal and the melt. So, throw a crystal of one composition into a new magma of another, the elements will begin to exchange over time starting at the rim of the crystal. So, assuming specific thermal parameters and compositional gradients, you can use diffusion as a clock – how long has the foreign crystal been exposed to this new magma based on how much diffusion of certain elements has occurred. Now, different elements have different abilities to diffused based on their size and charge, so you need to choose wisely.

The Druitt et al. (2012) study used these two petrologic characteristics of minerals and melt to determine two main conclusions: (1) the magma erupted from Santorini during the Minoan eruption in ~1600 BC was a mixed magma and (2) the intrusion that “got the ball rolling” towards the Minoan eruption and the subsequent mixing happened geologically quickly – in the the timescales of a century to a few months. Now, there is a big caveat not mentioned in the study to this second point. One quandary we have in petrology is that when we look at timescales of processes inside magmatic systems, diffusion profiles like the kind used in this study imply events occur much faster than if you try to date mixed crystals using radiometric elements (such as Ra, Th and U). This disconnect has not been resolved, so I would say that the timescales suggested by Druitt et al. (2012) are minimum timescales for the intrusion and mixing, not maximum. This will be important later on.

You might have noticed a lot of the media coverage about this study is claiming things like “supervolcanoes offer 100 year early warning” and “they may be predicted”. That is never said in the study. The authors do discuss some of the ways that this recharge/mixing might be manifested once the events have begun – interestingly not as “bulging” but rather “sagging” of the bottom of the magmatic system as the magma fills in, so uplift at Santorini might have been minimal. They actually predict that sinking of the land surface might be more likely rather than the classic St. Helens-1980-style bulge.

However, what I see as the biggest problem in this “early warning” claim is that it might still not be easily detectable – what if their timescale is off by even a factor of 2, so it takes 2 centuries to lead to an eruption? Human monitoring of an event 200 years in the making might be very problematic. Secondly, this intrusion isn’t a big event at 100 years than than over, it is growth and mixing over that century with a rapid culmination only months before the eruption according to Druitt et al. (2012). Whether or not this is detectable by current monitoring methods is unclear as well. The authors are right about one thing: “Long-term monitoring of large, dormant caldera systems, even in remote areas of the world, is essential if late-stage growth spurts of shallow magma reservoirs are to be detected well in advance of caldera-forming eruptions.” However, as usual, the many in the media has boiled down their research into meaningless copy that both misses the point of the research but also recklessly mischaracterizes the ramifications.

Image 1: Santorini caldera. Image by Navin75/Flickr.
Image 2: Figure 1 from Druitt et al., (2012)

<< Previous | Next >>

Moving big animals to places they don't already live is at once appealing and disturbing, a sort of adolescent environmental fantasy come to life: African lions in Nebraska! Komodo dragons in Australia!

But at the beginning of the 21st century, with 7 billion humans competing for space and resources on a rapidly warming planet, exercising arguable control over the fate of nature, moving species around is a legitimate option.

It's called assisted migration. Often the goal is to save endangered plants and animals, though not always. Sometimes, as with the Komodo dragon proposal, the goal is to restore ecological balance, and other proposals are motivated by an almost romantic sense of possibility: Wouldn't it be marvelous to watch cheetahs dash across the grasslands of South Dakota?

As an idea, assisted migration has been around for decades, but since the millennium's turn it's moved from a mostly fringe concept to something that scientists discuss, if not argue. After all, many examples of unwittingly assisted migration show what can happen when relocation goes wrong: Cane toads swarming across Australia, brown tree snakes devouring Guam's birds, kudzu swallowing much of the southeastern United States, and of course the voracious Burmese pythons of Florida.

On the flip side, however, are pheasants and sweet clover, brown trout and Norway maple, which despite their non-native origins are now considered a natural part of North American life. Sometimes relocation works fine, and an argument can be made that consciously acting as landscape-scale zookeepers and gardeners is a legitimate response to impending catastrophe.

Above:Komodo Dragons to Australia?

In a Feb. 1 Nature paper, biologist David Bowman of Australia's University of Tasmania raises the hypothetical possibility of introducing elephants and Komodo dragons to Australia. At first it sounds mad, but what's happening now in Australia is a form of madness, too. Massive wildfires that have become a regular and lethal fact of Australian life don't only represent climate change or natural susceptibility, but the buildup of vegetation that until 50,000 years ago would have been eaten by Australia's now-extinct megafauna.

Elephants could fill that role again, writes Bowman. "The idea of introducing elephants may seem absurd, but the only other methods likely to control gamba grass involve using chemicals or physically clearing the land, which would destroy the habitat," he writes. "Using mega-herbivores may ultimately be more practical and cost-effective." Komodo dragons wouldn't do much for fires, but they would eat feral pigs and buffalo, the targets of ongoing and largely unsuccessful animal control efforts.

Image: Komodo dragon (Adhi Rachdian/Flickr)

<< Previous | Next >> View all