Seeing Things: A New Transparent Display System Could Provide Heads-Up Data

Transparent displays have a variety of potential applications -- such as the ability to see navigation or dashboard information while looking through the windshield of a car or plane, or to project video onto a window or a pair of eyeglasses. A number of technologies have been developed for such displays, but all have limitations.

Now, researchers at MIT have come up with a new approach that can have significant advantages over existing systems, at least for certain kinds of applications: a wide viewing angle, simplicity of manufacture, and potentially low cost and scalability.

The innovative system is described in a paper published this week in the journal Nature Communications, co-authored by MIT professors Marin Soljačić and John Joannopoulos, graduate student Chia Wei Hsu, and four others.

Many current "heads-up" display systems use a mirror or beam-splitter to project an image directly into the user's eyes, making it appear that the display is hovering in space somewhere in front of him. But such systems are extremely limited in their angle of view: The eyes must be in exactly the right position in order to see the image at all. With the new system, the image appears on the glass itself, and can be seen from a wide array of angles.

Other transparent displays use electronics directly integrated into the glass: organic light-emitting diodes for the display, and transparent electronics to control them. But such systems are complex and expensive, and their transparency is limited.

The secret to the new system: Nanoparticles are embedded in the transparent material. These tiny particles can be tuned to scatter only certain wavelengths, or colors, or light, while letting all the rest pass right through. That means the glass remains transparent enough to see colors and shapes clearly through it, while a single-color display is clearly visible on the glass.

To demonstrate the system, the team projected a blue image in front of a scene containing cups of several colors, all of which can clearly be seen through the projected image.

While the team's demonstration used silver nanoparticles -- each about 60 nanometers across -- that produce a blue image, they say it should be possible to create full-color display images using the same technique. Three colors (red, green, and blue) are enough to produce what we perceive as full-color, and each of the three colors would still show only a very narrow spectral band, allowing all other hues to pass through freely.

"The glass will look almost perfectly transparent," Soljačić says, "because most light is not of that precise wavelength" that the nanoparticles are designed to scatter. That scattering allows the projected image to be seen in much the same way that smoke in the air can reveal the presence of a laser beam passing through it.

Such displays might be used, for example, to project images onto store windows while still allowing passersby to see clearly the merchandise on display inside, or to provide heads-up windshield displays for drivers or pilots, regardless of viewing angle.

Soljačić says that his group's demonstration is just a proof-of-concept, and that much work remains to optimize the performance of the system. Silver nanoparticles, which are commercially available, were selected for the initial testing because it was "something we could do very simply and cheaply," Soljačić says. The team's promising results, even without any attempt to optimize the materials, "gives us encouragement that you could make this work better," he says.

The particles could be incorporated in a thin, inexpensive plastic coating applied to the glass, much as tinting is applied to car windows. This would work with commercially available laser projectors or conventional projectors that produce the specified color.

Read more at Science Daily

This Spider Makes Fake Spiders. But Why?

A spider decoy built by a real spider (at the top of the decoy) in Peru.

TAMBOPATA, Peru – Scientists returned to the Amazon rainforest in December to collect data on one of their biggest finds of 2012: a spider that uses insect corpses and jungle trash to build big, spider-shaped decoys in its web.

But these Peruvian spiders, presumed to be a new species of Cyclosa, are not the sole sculptors of false arachnids. A second decoy spider lives in the Philippines, on the island of Negros. Finding two spiders that make such similar designs, 11,000 miles apart, has left scientists wondering how the behavior evolved and if the decoys serve as lures for prey or as an anti-predator defense system. The discoveries also suggest there may be even more sculpting arachnids.

You just have to know what to look for.

“The Philippine species and the Peruvian species, they both makes these decoys, but the architecture is different,” said entomologist Lary Reeves, a graduate student at the University of Florida who found the Philippine spider in March 2012. That spider decoy’s legs radiate outward from the body in all directions, while the Peruvian decoy’s legs tend to point downward.

Reeves was studying deforestation and butterfly communities on Mount Kanlaon, near the town of Murcia, when he noticed something odd along the trail leading down the mountain from his field site.

“I walked by this web with a spider in the middle,” Reeves said. “A couple steps past it, I realized it was a spider I hadn’t seen in the area before. I backtracked, looked, and saw that it was a decoy.”

The decoy was about the size of a half-dollar, constructed from debris and food carcasses, with eight legs radiating from its bulky center. It took Reeves awhile to find the spider that sculpted the false arachnid, but he eventually spotted it hiding in a pocket built into the decoy’s abdomen. It was just millimeters across, and well camouflaged by its building materials.

At the time, there was no way Reeves could know entomologist Phil Torres would soon find a similar spider in Peru, and that its artistic representations would crawl all over the internet.

In December, Reeves went to Peru with Torres to try to learn more about these spider-building spiders. The spiders live in an isolated patch of protected jungle along the Rio Tambopata, in the floodplain that surrounds the Tambopata Research Center.

There, Reeves and Torres and their colleagues spotted about a half-dozen of the spider-building spiders. The team photographed and measured the decoys daily, paying close attention to how the spiders rebuilt their decoys after seasonal rains turned them into soggy piles of web trash.

“I still think there were up to twice as many in the dry season,” Torres said, noting the relative dearth of decoy spiders in December. “There’s also a difference in how spiderlike the [decoys] are. Right after the rain, it collapses all the legs into this mush.”

That’s not surprising, given how fierce the daily downpours could be. But what Torres and Reeves couldn’t solidly answer is how – and how quickly – the spiders built their decoys.

They’re planning various experiments for follow-up visits, including stationing a video camera near one of the decoys for a 24-hour period and recording how the spider collects and incorporates building materials into the decoy. One of the key questions this method could answer, Torres says, it whether the spiders leave their webs and forage for decoy ingredients, or if they simply collect whatever falls into the web. Either way, it seems the spiders are resourceful.

“One that had recently molted had integrated his shed skin into the decoy,” Reeves noted.

Ultimately, the team would like to gather genetic material from the spiders and sequence it. Then, they’d like to use those sequences to understand how the decoy-building spiders — and their crazy constructions — are related to known Cyclosa species. Among groups of spiders, Cyclosa are well known for incorporating debris designs into their webs. But those designs are highly variable, and range from things like basic clumps of trash to these intricate, spidery shapes. Do the different designs correspond with different species’ positions on an evolutionary tree? Is it possible that more complex spider shapes are built by species that are more diverged from a common ancestor? Genetic sequencing has the ability to answer that question, but obtaining the permits needed to collect genetic material from the spiders has proven to be a long – and still incomplete – process.

Read more at Wired Science

Pelvic Bone in Storage May Be King Alfred the Great's

A piece of an ancient pelvis bone that had been tucked away in museum storage might belong to the English King Alfred the Great or his son Edward, scholars announced Friday (Jan. 17).

Archaeologists had mounted a search to find the lost remains of Alfred the Great, who was king of Wessex and dominated England from 871 until his death in 899. Last year, researchers exhumed an unmarked grave at Saint Bartholomew's Church in Winchester, England, but none of the bodies buried there were a match with Alfred.

After that initial disappointment, the group then turned to bones in storage boxes at the Winchester City Museum that had been excavated from a nearby monastery, Hyde Abbey, in the 1990s. There, they found a promising fragment of a pelvis bone. Radiocarbon tests showed that it dates between the years 895 and 1017. Further skeletal analysis showed that the bone belonged to a man who was between 26 and 45-plus years when he died, the researchers said.

If the remains are indeed Alfred's, the discovery would mark the second English king to be found in the United Kingdom less than two years. In 2012, archaeologists discovered the remains of King Richard III underneath a parking lot in Leicester. Last year, DNA testing helped confirm that the battle-scarred skeleton indeed belonged to Richard. The king's remains are set to be reburied this year.

Restless bones
"Given the age at death of the individual, and the probable male identity, the plausible candidates are King Alfred, [his son] King Edward the Elder, or the brother of King Edward, Æthelweard. All were buried in the Abbey," Katie Tucker, a researcher in human osteology at the University of Winchester, said in a statement.

When the pelvis bone was initially excavated in the late 1990s, it was found near the monastery's High Altar, where only Alfred and Edward had been buried, Tucker said, citing historical records.

"The discovery of the bone in a pit dug into the graves in front of the High Altar makes it far more likely that it comes from either Alfred or Edward," Tucker said.

Hyde Abbey was not Alfred's original resting place. It's believed the monarch was initially buried in the Anglo-Saxon cathedral in Winchester, called the Old Minster, in 899, though monks later moved his skeleton to New Minster and then Hyde Abbey, just outside the walls of Winchester.

Like many other Catholic institutions, Hyde Abbey was dismantled in the 16th century under Henry VIII during the so-called dissolution of the monasteries. The bodies buried at the monastery seem to have been allowed to remain, though some may have been disturbed when a prison was built on the site in the 18th century, said Barbara Yorke, professor emerita of early medieval history at the University of Winchester.

Read more at Discovery News

Usual Suspect: Is Distant Galaxy a Milky Way 'Baby'?

When searching for galaxies to study, it is easiest to pick out the biggest and brightest. This is especially true if you want to look at very distant galaxies; ones that were around when the Universe was very young. It is quite a challenge to pick out a faint, normal, almost “boring” galaxy from a time long ago, but when astronomers used the 10-meter Keck telescope to do just that, it was pretty exciting.

The galaxy, called DLA2222-0946, was first discovered in absorption, meaning that it was blocking some of the light of a distant quasar behind it in a very specific way. In fact, the first few letters of its name stand for “Damped Lyman-alpha,” a system where the neutral hydrogen in a galaxy absorbs certain frequencies of light from the background quasar. It is thought that these massive reservoirs of neutral gas are the progenitors of today’s Milky Way-like galaxies.

Top: A map of the hydrogen emission from DLA2222-0946. The mapped region, which covers only a portion of the galaxy, is about 5,000 parsecs (or 16,300 light-years) across. The position of the background quasar is marked by a “Q”. Bottom: The corresponding map of the movement of the gas in the galaxy. Red means moving away from us; blue is moving towards us.

This galaxy was then detected by the huge 10-meter telescope Keck I telescope. Not only was it detected, but it was resolved, meaning that astronomers could get some spatial information from it. As you can see above, the pictures are jaw-droppingly amazing, but the information contained in those images is important. In order to get such a clear picture, the team used the Laser Guide Star Adaptive Optics system, or a laser guide “star” for calibration and real-time adjustments to the telescope mirrors to compensate for the turbulence of the atmosphere.

The astronomers also used the OSIRIS instrument on Keck. This get you a spectrum of every pixel in the image in infrared wavelengths. So, not only could they detect the massive hydrogen reservoirs in the galaxy, the astronomers could see how the gas was moving. Now, DLA2222-0946 is not just known by the small portion of it that blocks the light of a distant quasar, but becomes a whole galaxy to explore. It seems to be a disk galaxy seen edge-on.

We see this galaxy as it exists 10.8 billion years ago, during a prolific epoch of star formation in the Universe. However, this relatively normal galaxy seems to be forming stars at a rate of ten times the mass of the sun per year, or ten times the current star formation rate of the Milky Way today. The galaxy is about 6 million times the mass of the sun, so small in comparison to today’s Milky Way.

The astronomers detected oxygen and nitrogen emission lines in the galaxy, allowing them to estimate the “metallicity” of the galaxy. This comes from the older definition of “metals” from astronomy, anything on the periodic table that’s not hydrogen and helium. We care about metallicity because it tells something about how many epochs of star formation came before, since elements heavier than helium come from the cores of and violent explosions of massive stars. It also tells you something about when planetary systems can be formed, particularly rocky planets, as these are composed almost entirely of NOT hydrogen and helium.

Read more at Discovery News

Distant Quasar Illuminates a Filament of the Cosmic Web

Astronomers have discovered a distant quasar illuminating a vast nebula of diffuse gas, revealing for the first time part of the network of filaments thought to connect galaxies in a cosmic web. Researchers at the University of California, Santa Cruz, led the study, published January 19 in Nature.

Using the 10-meter Keck I Telescope at the W. M. Keck Observatory in Hawaii, the researchers detected a very large, luminous nebula of gas extending about 2 million light-years across intergalactic space.

"This is a very exceptional object: it's huge, at least twice as large as any nebula detected before, and it extends well beyond the galactic environment of the quasar," said first author Sebastiano Cantalupo, a postdoctoral fellow at UC Santa Cruz.

The standard cosmological model of structure formation in the universe predicts that galaxies are embedded in a cosmic web of matter, most of which (about 84 percent) is invisible dark matter. This web is seen in the results from computer simulations of the evolution of structure in the universe, which show the distribution of dark matter on large scales, including the dark matter halos in which galaxies form and the cosmic web of filaments that connect them. Gravity causes ordinary matter to follow the distribution of dark matter, so filaments of diffuse, ionized gas are expected to trace a pattern similar to that seen in dark matter simulations.

Until now, however, these filaments have never been seen. Intergalactic gas has been detected by its absorption of light from bright background sources, but those results don't reveal how the gas is distributed. In this study, the researchers detected the fluorescent glow of hydrogen gas resulting from its illumination by intense radiation from the quasar.

"This quasar is illuminating diffuse gas on scales well beyond any we've seen before, giving us the first picture of extended gas between galaxies. It provides a terrific insight into the overall structure of our universe," said coauthor J. Xavier Prochaska, professor of astronomy and astrophysics at UC Santa Cruz.

The hydrogen gas illuminated by the quasar emits ultraviolet light known as Lyman alpha radiation. The distance to the quasar is so great (about 10 billion light-years) that the emitted light is "stretched" by the expansion of the universe from an invisible ultraviolet wavelength to a visible shade of violet by the time it reaches the Keck Telescope. Knowing the distance to the quasar, the researchers calculated the wavelength for Lyman alpha radiation from that distance and built a special filter for the telescope's LRIS spectrometer to get an image at that wavelength.

"We have studied other quasars this way without detecting such extended gas," Cantalupo said. "The light from the quasar is like a flashlight beam, and in this case we were lucky that the flashlight is pointing toward the nebula and making the gas glow. We think this is part of a filament that may be even more extended than this, but we only see the part of the filament that is illuminated by the beamed emission from the quasar."

A quasar is a type of active galactic nucleus that emits intense radiation powered by a supermassive black hole at the center of the galaxy. In an earlier survey of distant quasars using the same technique to look for glowing gas, Cantalupo and others detected so-called "dark galaxies," the densest knots of gas in the cosmic web. These dark galaxies are thought to be either too small or too young to have formed stars.

"The dark galaxies are much denser and smaller parts of the cosmic web. In this new image, we also see dark galaxies, in addition to the much more diffuse and extended nebula," Cantalupo said. "Some of this gas will fall into galaxies, but most of it will remain diffuse and never form stars."

Read more at Science Daily

Peeking Into Schrödinger's Box

Until recently measuring a 27-dimensional quantum state would have been a time-consuming, multistage process using a technique called quantum tomography, which is similar to creating a 3D image from many 2D ones. Researchers at the University of Rochester have been able to apply a recently developed, alternative method called direct measurement to do this in a single experiment with no post-processing. The work is of interest because fast, accurate and efficient methods for characterizing high-dimensional states like this could be central in developing high security quantum communications systems, as well as to probe our fundamental understanding of quantum mechanics.

The work was published this week in Nature Communications by a team of researchers from the University of Rochester and the University of Glasgow. In the paper they demonstrate direct measurements of the quantum state associated with the orbital-angular momentum.

"Our work shows that direct measurement offers an exciting alternative to quantum tomography," said Robert Boyd, Professor of Optics and Physics at the University of Rochester and Canada Excellence Research Chair in Quantum Nonlinear Optics at the University of Ottawa. "As the field of quantum information continues to advance, we expect direct measurement to play an increasingly important role in this." Boyd added that although it is unclear exactly how much more efficient direct measurement is compared to quantum tomography, the lack of post-processing is a major factor in speeding-up direct measurements.

The direct measurement technique offers a way to directly determine the state of a quantum system. It was first developed in 2011 by scientists at the National Research Council Canada, who used it to determine the position and momentum of photons. Last year, a group of Rochester/Ottawa researchers led by Boyd showed that direct measurement could be applied to measure the polarization states of light. The new paper is the first time this method has been applied to a discrete, high dimensional system.

Such direct measurements of the wavefunction might have appeared to be ruled out by the uncertainty principle -- the idea that certain properties of a quantum system could be known with precision only if other properties were known poorly. However, direct measurement involves a "trick" that makes it possible.

Direct measurements consists of two types of measurements performed one after the other, first a "weak" measurement followed by a "strong" measurement. In quantum mechanics the act of measuring a quantum state disturbs it irreversibly, a phenomenon referred to as collapse of the wavefunction. The trick lies with the first measurement being so gentle that it only slightly disturbs the system and does not cause the wavefunction to collapse. "It is sort of like peeking into the box to see if Schrodinger's cat is alive, without fully opening the box," said lead author Dr. Mehul Malik, currently a post-doctoral research fellow at the University of Vienna and who was a Ph.D. in Boyd's group when the work was performed. "The weak measurement is essentially a bad measurement, which leaves you mostly uncertain about whether the cat is alive or dead. It does, however¬, give partial information on the health of the cat, which when repeated many times can lead to near certain information as to whether the cat is alive or dead." Malik adds that the beauty of the weak measurement is that it does not destroy the system, unlike most standard measurements of a quantum system, allowing a subsequent measurement -- the "strong" measurement of the other variable.

Read more at Science Daily

Milky Way May Have Formed 'Inside-Out:' Gaia Provides New Insight Into Galactic Evolution

A breakthrough using data from the Gaia-ESO project has provided evidence backing up theoretically predicted divisions in the chemical composition of the stars that make up the Milky Way's disc -- the vast collection of giant gas clouds and billions of stars that give our Galaxy its 'flying saucer' shape.

By tracking the fast-produced elements, specifically magnesium in this study, astronomers can determine how rapidly different parts of the Milky Way were formed. The research suggests that stars in the inner regions of the Galactic disc were the first to form, supporting ideas that our Galaxy grew from the inside-out.

Using data from the 8-m VLT in Chile, one of the world's largest telescopes, an international team of astronomers took detailed observations of stars with a wide range of ages and locations in the Galactic disc to accurately determine their 'metallicity': the amount of chemical elements in a star other than hydrogen and helium, the two elements most stars are made from.

Immediately after the Big Bang, the Universe consisted almost entirely of hydrogen and helium, with levels of "contaminant metals" growing over time. Consequently, older stars have fewer elements in their make-up -- so have lower metallicity.

"The different chemical elements of which stars -- and we -- are made are created at different rates -- some in massive stars which live fast and die young, and others in sun-like stars with more sedate multi-billion-year lifetimes," said Professor Gerry Gilmore, lead investigator on the Gaia-ESO Project.

Massive stars, which have short lives and die as 'core-collapse supernovae', produce huge amounts of magnesium during their explosive death throes. This catastrophic event can form a neutron star or a black hole, and even trigger the formation of new stars.

The team have shown that older, 'metal-poor' stars inside the Solar Circle -- the orbit of our Sun around the centre of the Milky Way, which takes roughly 250 million years to complete -- are far more likely to have high levels of magnesium. The higher level of the element inside the Solar Circle suggests this area contained more stars that "lived fast and die young" in the past.

The stars that lie in the outer regions of the Galactic disc -- outside the Solar Circle -- are predominantly younger, both 'metal-rich' and 'metal-poor', and have surprisingly low magnesium levels compared to their metallicity.

This discovery signifies important differences in stellar evolution across the Milky Way disc, with very efficient and short star formation timescales occurring inside the Solar Circle; whereas, outside the Sun's orbit, star formation took much longer.

"We have been able to shed new light on the timescale of chemical enrichment across the Milky Way disc, showing that outer regions of the disc take a much longer time to form," said Maria Bergemann from Cambridge's Institute of Astronomy, who led the study.

"This supports theoretical models for the formation of disc galaxies in the context of Cold Dark Matter cosmology, which predict that galaxy discs grow inside-out."

The findings offer new insights into the assembly history of our Galaxy, and are the part of the first wave of new observations from the Gaia-ESO survey, the ground-based extension to the Gaia space mission -- launched by the European Space Agency at the end of last year -- and the first large-scale survey conducted on one the world's largest telescopes: the 8-m VLT in Paranal, Chile.

The study is published online today through the astronomical database Astro-ph, and has been submitted to the journal Astronomy and Astrophysics.

The new research also sheds further light on another much debated "double structure" in the Milky Way's disc -- the so-called 'thin' and 'thick' discs.

"The thin disc hosts spiral arms, young stars, giant molecular clouds -- all objects which are young, at least in the context of the Galaxy," explains Aldo Serenelli from the Institute of Space Sciences (Barcelona), a co-author of the study. "But astronomers have long suspected there is another disc, which is thicker, shorter and older. This thick disc hosts many old stars that have low metallicity."

During the latest research, the team found that:

• Stars in the young, 'thin' disc aged between 0 -- 8 billion years all have a similar degree of metallicity, regardless of age in that range, with many of them considered 'metal-rich'.
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• There is a "steep decline" in metallicity for stars aged over 9 billion years, typical of the 'thick' disc, with no detectable 'metal-rich' stars found at all over this age.
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• But stars of different ages and metallicity can be found in both discs.

"From what we now know, the Galaxy is not an 'either-or' system. You can find stars of different ages and metal content everywhere!" said Bergemann. "There is no clear separation between the thin and thick disc. The proportion of stars with different properties is not the same in both discs -- that's how we know these two discs probably exist -- but they could have very different origins."

Added Gilmore: "This study provides exciting new evidence that the inner parts of the Milky Way's thick disc formed much more rapidly than did the thin disc stars, which dominate near our Solar neighbourhood."

Read more at Science Daily

Hello World: Hibernating Rosetta Comet Probe Awakens

Europe’s Rosetta spacecraft ended a nearly three-year hibernation on Monday to prepare for an unprecedented mission to orbit a comet and dispatch a lander to the surface.

Rosetta’s on-board alarm clock went off a 5 a.m. EST, but it took the spacecraft seven hours to warm up its star trackers,  fire up rocket thrusters to slow its spin, turn on its transmitter and beam a message back to Earth.

The probe, presently located about 500 million miles (about 800 million km) from Earth and just shy of Jupiter’s orbit, is so far away that its radio transmissions, traveling at the speed of light, take 45 minutes to reach Earth.

Ground control teams got word that Rosetta was awake at 1:18 p.m. EST.

“We have our comet-chaser back,” said Alvaro Giménez, who oversees science and robotic exploration at the European Space Agency, said in a statement.

The mission has also recommenced the use of its Twitter account, @ESA_Rosetta, just after the spacecraft woke up. It tweeted “Hello, world!” in 23 European languages.

Rosetta, which carries a 220-pound (100 kilogram) lander called Philae, has been shut down for most of the past three years to save power. It is due to reach a 2.4-mile (4 kilometer) diameter comet called 67P/Churyumov-Gerasimenko in August.

From Discovery News

Tiny Swimming Bio-Bots Boldly Go Where No Bot Has Swum Before

The alien world of aquatic micro-organisms just got new residents: synthetic self-propelled swimming bio-bots.

A team of engineers has developed a class of tiny bio-hybrid machines that swim like sperm, the first synthetic structures that can traverse the viscous fluids of biological environments on their own. Led by Taher Saif, the University of Illinois Gutgsell Professor of mechanical science and engineering, the team published its work in the journal Nature Communications.

"Micro-organisms have a whole world that we only glimpse through the microscope," Saif said. "This is the first time that an engineered system has reached this underworld."

The bio-bots are modeled after single-celled creatures with long tails called flagella -- for example, sperm. The researchers begin by creating the body of the bio-bot from a flexible polymer. Then they culture heart cells near the junction of the head and the tail. The cells self-align and synchronize to beat together, sending a wave down the tail that propels the bio-bot forward.

This self-organization is a remarkable emergent phenomenon, Saif said, and how the cells communicate with each other on the flexible polymer tail is yet to be fully understood. But the cells must beat together, in the right direction, for the tail to move.

"It's the minimal amount of engineering -- just a head and a wire," Saif said. "Then the cells come in, interact with the structure, and make it functional."

See an animation of the bio-bots in motion and a video of a free-swimming bot.

The team also built two-tailed bots, which they found can swim even faster. Multiple tails also opens up the possibility of navigation. The researchers envision future bots that could sense chemicals or light and navigate toward a target for medical or environmental applications.

"The long-term vision is simple," said Saif, who is also part of the Beckman Institute for Advanced Science and Technology at the U. of I. "Could we make elementary structures and seed them with stem cells that would differentiate into smart structures to deliver drugs, perform minimally invasive surgery or target cancer?"

The swimming bio-bot project is part of a larger National Science Foundation-supported Science and Technology Center on Emergent Behaviors in Integrated Cellular Systems, which also produced the walking bio-bots developed at Illinois in 2012.

Read more at Science Daily

Chimps Can Use Gestures to Communicate in Hunt for Food

Remember the children's game "warmer/colder," where one person uses those words to guide the other person to a hidden toy or treat? Well, it turns out that chimpanzees can play, too.

Researchers at Georgia State University's Language Research Center examined how two language-trained chimpanzees communicated with a human experimenter to find food. Their results are the most compelling evidence to date that primates can use gestures to coordinate actions in pursuit of a specific goal.

The team devised a task that demanded coordination among the chimps and a human to find a piece of food that had been hidden in a large outdoor area. The human experimenter did not know where the food was hidden, and the chimpanzees used gestures such as pointing to guide the experimenter to the food.

Dr. Charles Menzel, a senior research scientist at the Language Research Center, said the design of the experiment with the "chimpanzee-as-director" created new ways to study the primate.

"It allows the chimpanzees to communicate information in the manner of their choosing, but also requires them to initiate and to persist in communication," Menzel said. "The chimpanzees used gestures to recruit the assistance of an otherwise uninformed person and to direct the person to hidden objects 10 or more meters away. Because of the openness of this paradigm, the findings illustrate the high level of intentionality chimpanzees are capable of, including their use of directional gestures. This study adds to our understanding of how well chimpanzees can remember and communicate about their environment."

The paper, "Chimpanzees Modify Intentional Gestures to Co-ordinate a Search for Hidden Food," has been published in Nature Communications. Academics at the University of Chester and University of Stirling collaborated on the research project.

Dr. Anna Roberts of the University of Chester said the findings are important.

"The use of gestures to coordinate joint activities such as finding food may have been an important building block in the evolution of language," she said.

Dr. Sarah-Jane Vick of the University of Stirling added, "Previous findings in both wild and captive chimpanzees have indicated flexibility in their gestural production, but the more complex coordination task used here demonstrates the considerable cognitive abilities that underpin chimpanzee communication."

Dr. Sam Roberts, also from the University of Chester, pointed out the analogy to childhood games.

"This flexible use of pointing, taking into account both the location of the food and the actions of the experimenter, has not been observed in chimpanzees before," Roberts said.

Read more at Science Daily