The structural memory of water persists on a picosecond timescale

The lifetime of local water structures is probed using ultrafast laser pulses.

A team of scientists from the Max Planck Institute for Polymer Research (MPI-P) in Mainz, Germany and FOM Institute AMOLF in the Netherlands has characterized the local structural dynamics of liquid water, i.e. how quickly water molecules change their binding state. Using innovative ultrafast vibrational spectroscopies, the researchers show why liquid water is unique when compared to most other molecular liquids. This study has recently been published in the scientific journal Nature Communications.

With the help of a novel combination of ultrafast laser experiments, the scientists found that local structures persist in water for longer than a picosecond, a picosecond (ps) being one thousandth of one billionth of a second (10-12 s). This observation changes the general perception of water as a solvent. "71% of Earth's surface is covered with water. As most chemical and biological reactions on earth occur in water or at the air water interface in oceans or in clouds, the details of how water behaves at the molecular level are crucial. Our results show that water cannot be treated as a continuum, but that specific local structures exist and are likely very important" says Mischa Bonn, director at the MPI-P.

Water is a very special liquid with extremely fast dynamics. Water molecules wiggle and jiggle on sub-picosecond timescales, which make them undistinguishable on this timescale. While the existence of very short-lived local structures -- e.g. two water molecules that are very close to one another, or are very far apart from each other -- is known to occur, it was commonly believed that they lose the memory of their local structure within less than 0.1 picoseconds.

The proof for relatively long-lived local structures in liquid water was obtained by measuring the vibrations of the Oxygen-Hydrogen (O-H) bonds in water. For this purpose the team of scientists used ultrafast infrared spectroscopy, particularly focusing on water molecules that are weakly (or strongly) hydrogen-bonded to their neighboring water molecules. The scientists found that the vibrations live much longer (up to about 1 ps) for water molecules with a large separation, than for those that are very close (down to 0.2 ps). In other words, the weakly bound water molecules remain weakly bound for a remarkably long time.

From Science Daily

Advanced LIGO Resumes Quest for Gravitational Waves

After undergoing a 5-year upgrade, the world’s most powerful gravitational wave detector is back online and hunting for the tiniest of tiny fluctuations in spacetime.

The Laser Interferometer Gravitational-wave Observatory (or LIGO) consists of 2 facilities (in Washington and Louisiana) designed to detect the passage of gravitational waves in local spacetime. Gravitational waves are generated by the acceleration and deceleration of huge masses in the cosmos; extreme cosmic events such as black hole collisions and supernovae are predicted to generate them. Like ripples propagating across the surface of a pond, gravitational waves ripple through spacetime, carrying energy away from these events.

Should we have the ability to directly detect these waves, a new era of gravitational wave astronomy will be possible, where we can use gravitational wave signals to open our eyes to some of the most energetic events in the universe.

LIGO’s initial observing run started in 2002 and ended in 2010, but during those first 8 years LIGO did not detect any gravitational wave signals. So, through a series of upgrades to reduce the amount of unwanted noise interfering with the facility’s interferometers, Advanced LIGO is now taking a giant leap into a new regime of precision in the hunt for these elusive spacetime ripples. And on Friday, Advanced LIGO went online at a sensitivity 3-times that of its predecessor.

According to the Advanced LIGO team, the new and improved detectors should be able to detect gravitational waves “from as far away as 225 million light years.” By the end of LIGO’s last search, the system was only able to reach out to 65 million light-years. (For reference, Advanced LIGO can detect gravitational waves generated 10 times further away than Andromeda, the Milky Way’s nearest massive galactic neighbor.) This boost in sensitivity means that Advanced LIGO can now access a volume of space 27 times that of its last observing run.

Gravitational waves are predicted by Einstein’s general relativity and astrophysicists know they are out there through indirect observations of their effects. But direct observations of gravitational waves through local space have have been maddeningly elusive. The fact that LIGO has yet to find a gravitational wave signal is a fascinating result unto itself — it means that gravitational wave signatures are weaker than predicted and we need more sensitive detectors (like Advanced LIGO) to detect them.

Although the search has been difficult so far, leading physicists behind this monumental experiment are not hiding their optimism that Advanced LIGO will detect these ripples in spacetime.

“We are there; we are in the ball park now. It’s clear that this is going to be pulled off,” Kip Thorne, Caltech theoretical physicist and one of the pioneers of the LIGO experiment, told BBC World Service. He added that it would be “quite surprising” if Advanced LIGO doesn’t find hints of gravitational waves.

“Experimental attempts to find gravitational waves have been on going for over 50 years, and they haven’t yet been found,” said David Reitze, executive director of the LIGO program at Caltech, in a press release. “They’re both very rare and possess signal amplitudes that are exquisitely tiny.”

Read more at Discovery News

Dirty Waters Could Get Even Dirtier With Warming

A warmer, wetter climate in the eastern United States could also boost pollution from cities and farms draining into rivers, lakes and streams, according to a new report, and federal rules may not be flexible enough to handle it.

Researchers at the Rand Corporation examined two watersheds—the Patuxent River in Maryland and the North Farm Creek tributary of the Illinois River—to explore how the EPA’s water quality plans would hold up during the future uncertainty of climate change.

In both regions, the study found that EPA’s proposed plans meet the agency’s water quality goals in under current assumptions of the region’s climate, but do not meet water quality goals under future scenarios.

“What we were doing was thinking about future vulnerabilities,” said Jordan Fischbach, a report author and co-director of Rand’s Center for Water and Climate Resilience. “How might the amount of pollution change in these different futures. All the states whose waters feed into the Chesapeake Bay, they’ve set ambitious targets, can you do that?”

The Maryland case looked at rules governing urban stormwater runoff from parking lots and city streets. The Chesapeake Bay ecosystem and its bounty of native oysters, crabs and fish species, is still struggling despite decades of work by states and local governments to control runoff.

The Illinois example looked at agricultural runoff from farms, which flows downstream and ends up in the Mississippi River. In fact, freshwater flows of the Mississippi carry an overabundance of nitrogen and phosphorous, primarily from farms, into the Gulf of Mexico. Each year, this runoff plume creates a so-called “dead zone” of oxygen-starved water that kills bottom-dwelling marine life.

Estimates by the International Panel on Climate Change (IPCC) and the National Climate Assessment call for a wetter and warmer eastern United States.

“The trend is wetter, but it ranges from drier to a whole lot wetter,” said Robert Lempert, senior scientist and director of Rand’s director of long-range policy and human condition.

“Whether its farmland or a parking lot, when you run it in a simulation model, you see that as you increase rainfall, you increase the pollutants deposited into a river or stream,” Fischbach added.

This climate-juiced rainfall might double pollution levels by 2050, the researchers said.

Solutions include building more “green infrastructure” to treat runoff before it reaches the river. This includes things like using grass waterways to slow down runoff, leaving tillage from harvested crops on the ground so rainwater doesn’t hit not bare soil and building parking lots with grass strips to help water soak into the ground.

Read more at Discovery News

5,000-Year-Old Throne Found in Turkey

The remains of a 5,000-year-old adobe basament of a possible “throne” have been unearthed during excavations in Turkey, revealing the origins of the secularization of power and one of the first evidence of the birth of the state system.

Discovered in Aslantepe in the eastern Turkish province of Malatya, the structure consists of an adobe platform, raised by three steps above the floor, on top of which burnt wooden pieces were found.

“The burnt wooden fragments are likely the remains of a chair or throne,” excavation director Marcella Frangipane of La Sapienza University in Rome, told Discovery News.

Frangipane, who has long been digging at the site, is working to bring to light a huge complex dating to the fourth millennium B.C. (3350-3100 A.C.)

“It’s the world’s first evidence of a real palace and it is extremely well preserved, with walls standing two meters high,” Frangipane said.

The complex features two temples, storage rooms, various buildings and a large entrance corridor. Some walls are decorated with red and black motifs and with geometrical impressed patterns.

“In the past two campaigns we found a large courtyard which can be reached through the corridor. On the courtyard stands a monumental building,” Frangipane said.

Within such building, the archaeologists unearthed the adobe platform. It stood in a small room which opened into the courtyard.

Frangipane believes the chief or king appeared in the throne room to give audience to the public, gathered in the large courtyard.

In front of the platform where the throne likely stood, the archaeologists also unearthed two small and low adobe platforms, probably made for people to stand on while they appeared before the king.

“This reception courtyard and building were not a temple complex, they rather appear as the heart of the palace. We do not have religious rites here, but a ceremony showing the power of the ‘king’ and the state,” Frangipane said.

Read more at Discovery News

Spacing Out Vaccines? No Evidence Supports Candidates' Ideas

There is no evidence that supports spacing out childhood vaccines — which two Republican candidates for president suggested in Wednesday night’s presidential debate — instead of following the recommended schedule, experts say.

“I am totally in favor of vaccines, but I want smaller doses over a longer period of time,” Donald Trump, one of the candidates for president, said at the debate.

Candidate and retired pediatric neurosurgeon Ben Carson responded by saying, “We have extremely well-documented proof that there is no autism associated with vaccinations,” he said.

Carson went on, however, to agree with Trump about spacing out vaccines. “But it is true that we are probably giving way too many in too short period of time, and a lot of pediatricians now recognize that, and I think are cutting down on the number and the proximity in which those are done” he said.

Candidate Senator Rand Paul, an ophthalmologist, also agreed.

“I’m for vaccines, but I’m also for freedom,” he said. “Even if the science doesn’t say bunching them up is a problem, I ought to be able to spread my vaccines out a little bit at the very least.”

But not only is there no evidence that spacing out childhood vaccines is good for children’s health, but the evidence actually suggests quite the opposite, Dr. Paul Offit, chief of the division of infectious diseases at the Children’s Hospital of Philadelphia, told Live Science.

There’s evidence that supports not spacing out vaccines any further than they are scheduled under current recommendations, Offit said.

“To suggest that you make your own schedule is dangerous,” he said. “That’s why we saw the measles outbreak in Disneyland this year” he said — because parents chose to delay vaccinating their children.

Spacing out the current vaccine schedule leaves children susceptible to diseases for longer periods of time than they need to be, Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University, told Live Science.

Moreover, spacing out vaccines is an unproven way to vaccinate: No one’s ever tested it, so scientists don’t know how well it works or how safe it is, he said.

And it’s been documented that a vaccine that is pushed back can become a vaccine that is never received, Schaffner added.

Although some parents have raised concerns that an infant’s immune system may not be able to “handle” the numerous immunizations children are scheduled to receive, there is no evidence that shows this is true, Schaffner said. “That’s been shown clearly not to be the case,” he said. “It’s safe and effective.”

Read more at Discovery News

This Tiny Adorable Critter Is Half Kangaroo, Half Velociraptor

This bouncing jerboa is so cute that I just had four, maybe five heart attacks.

Kangaroos are played out. I mean, they’re great and all, and I say that not just because they scare me a bit, but they’re just so 2014. Hopping around, eating grass, kickboxing the tar out of each other. I’m over it. Mostly because another group of perfectly good creatures is hopping around in a remarkably similar manner, only much more adorably: the 30-odd species of achingly cute, bipedal jerboa, rodents with all the kangaroo’s legs and none of the crummy attitude.

Just look at that thing. The top part looks enough like a mouse, but those legs. What’s going on there? (To be clear, jerboas do have two other limbs like any other rodent, but they’re tiny and tucked against the face and for the love of God how is it possible that everything about this creature is so adorable?)

Well, though it may look like it, the knees are not in fact inverted. The jerboa’s knee is actually hard to make out, butting up against its torso. That extremely long section is called the cannon bone, and it’s made up fused metatarsal bones—the longest ones in the center of your foot. The tiny bits of the foot that actually make contact with the ground are the toes, so the jerboa in fact spends its life tiptoeing around. Some species even look like they’re wearing shoes, on account of the tufts of hair on their toes. Those stiff fibers act a bit like snowshoes, giving the rodent some extra purchase in the sandy deserts they call home, places like North Africa and the Arabian Peninsula and Asia.

The elongated legs bestow the jerboa with incredible speed and leaping abilities, like a tiny kangaroo on amphetamines. “This is an animal that’s about the size of your fist,” says biomechanist Talia Moore of Harvard University, who studies their locomotion, “yet there have been reports that some species can easily hop over six feet.”

Watch this on The Scene.

  That long, elegant tail also probably plays a role in balance. Moore and other researchers need to do more work to determine exactly what’s going on, but by manipulating its tail, the jerboa can likely help stabilize itself as it’s speeding around the desert. And it’s not the only one: Velociraptors likely used their tails in the same way. (Interestingly, Moore did research as an undergrad on lizard and velociraptor locomotion, showing just how important a tail is for orientation in those creatures. Double interestingly, she says that the folks who recently built a jerboa robot used her undergrad work as a reference.)

Leading the research into the utility of jerboa tails was a certain Frenchman, who, unrestrained by the moral considerations of modern science, went a bit too far in his experiments. “There have been historical observations where in the 1800s this cruel Frenchman cut off a jerboa’s tail, and it just wasn’t able to do anything,” says Moore. “It couldn’t even sit up, it couldn’t jump around, it was just a pathetic, sad jerboa.”

The stunt was not … well received. “There are multiple publications from around 1835,” Moore adds, “where they’re all talking about this ‘cruel Frenchman.’ Those exact words.” One naturalist oh-so-eloquently chastised the mutilator: “We would remind such persons, that although the Creator has given us the faculties, and permits us to use them in studying his works, we have no right to violate the common feelings of humanity towards his creatures.”

Jerboas are even adorable in the lab. Do you have any idea how hard it is to be adorable in a lab?

Alright, now that that’s out of the way, we can get back to the many additional wonders of the jerboas. They’re vegetarians, specifically crepuscular vegetarians, meaning they forage at twilight, mainly for seeds. And seeds not only bestow them with requisite nutrition but also water, so much so that they never need to drink.

Here’s the problem, though: Jerboas share not only a habitat with the gerbil (yes, it still exists in the wild, outside the clutches of over-enthusiastic 5-year-olds), but a niche as well, for gerbils love them some seeds too. And it can be problematic for two species to compete over the same limited resource—the desert isn’t exactly overflowing with plants and seeds.

Both species have another serious problem on their hands in the form of birds of prey. Yet while the gerbil tends to hang out in the relative safety of shrubbery, the jerboa instead opts to take its chances out in the open. But why? Well, for the jerboa and gerbil, the problems of competition and predation are intertwined.

Consider how predatory birds hunt: They have one shot at pinpointing a moving target and diving in. “If you think about it,” Moore says, “nocturnal birds of prey have just one single strike that they have to commit to, they have to predict where their prey animal is going and then meet up with them there. And so if the jerboa does something that’s unpredictable, like jump straight up or jump in a zig zag, it makes it really difficult for the birds of prey to plot an effective intercept course.”

Even adorable with flash! Do you have any idea how hard it is to be adorable with a flash?

A gerbil simply isn’t equipped to deal with this out in the open. If a predator is on its tail, it’s pretty much just full steam straight ahead back to its burrow. This, therefore, limits the gerbil in its foraging. It’s forced to stick to shelter underneath a bush, preferably somewhere close to its burrow.

Eff that noise, says the jerboa. It bravely ventures way out into the world (Moore usually finds them chilling on dirt roads). Here it roots around for seeds with eyes on the sky. Should a predator swoop in, it can tear away, zig-zagging and praying that the raptor miscalculates its strike.

Thus the gerbil and jerboa can occupy the same niche without competing: They never really run up against each other because they’re exploring different microhabitats. Indeed, if you put a jerboa and a gerbil in a cage, they won’t mind each other one bit, not exactly what you’d expect if two different species were used to fighting over resources in the wild.

Read more at Wired Science

New Bee Species Have Narrow Heads, Long Mouths

Four new bee species — three of which have narrow heads and unusually long mouth parts — have just been discovered in Australia.

The bees, spotted during the nature discovery project called Bush Blitz, evolved their unique features to feed on a particular native plant.

“Three of the species belong to the group of bees that feed on the flowers of emu bushes,” Katja Hogendoorn of the University of Adelaide explained in a press release. “The way they have adapted to be able to feed on these flowers is a great example of co-evolution.”

She continued: “These bees have narrow faces and very long mouth parts to collect the nectar through a narrow constriction at the base of the emu bush flowers. The fourth species belongs to a different group within this large genus and has a normally round-shaped head.”

The genus, Euhesma, was determined based on evaluation of DNA “barcoding” and a detailed comparison of the bees with museum specimens.

The bees were found as the researchers explored Bon Bon Station Reserve, south of Coober Pedy in South Australia, and Cane River Conservation Park in the Pilbara region of Western Australia.

Hogendoorn and colleagues believe that only two-thirds of Australian bee species are now known to science, so many more such discoveries are expected in future, if the bees do not become extinct beforehand.

“Habitat loss and pesticides are the main cause of native bee declines in Europe and the United States, but the conservation status of native Australian bees is largely unknown,” Hogendoorn said.

Read more at Discovery News

Weird Pre-Reptile Was First to Walk on All Fours

A pre-reptile that looks like a cross between a modern lizard and a hippo is believed to be the earliest known creature to walk on all fours, according to new research from Brown University.

As it roamed Pangaea 260 million years ago, the cow-sized herbivore Bunostegos akokanensis stood out — quite literally — from its peers, which were best described as "sprawlers," creatures whose limbs extended out from the side of their body, pointing sideways instead of downward.

In 2003, however, a B. akokanensis specimen’s unique shoulder and elbow joints tipped paleontologists off to the creature’s unexpected posture.

“A lot of the animals that lived around the time had a similar upright or semi-upright hind limb posture, but what’s interesting and special about Bunostegos is the forelimb, in that its anatomy is sprawling --precluding and seemingly directed underneath its body -- unlike anything else at the time,” study lead author Morgan Turner said in a news release.

“The elements and features within the forelimb bones won’t allow a sprawling posture. That is unique.”

According to researchers, walking upright is more energy efficient than sprawling. In an area where food and water were hard to come by, those energy savings could have proved crucial to B. akokanensis‘ survival.

Turner’s research is published in the Journal of Vertebrate Paleontology.

From Discovery News

16 Pyramids Discovered in Ancient Cemetery

The remains of 16 pyramids with tombs underneath have been discovered in a cemetery near the ancient town of Gematon in Sudan.

They date back around 2,000 years, to a time when a kingdom called “Kush” flourished in Sudan. Pyramid building was popular among the Kushites. They built them until their kingdom collapsed in the fourth century AD.

Derek Welsby, a curator at the British Museum in London, and his team have been excavating at Gematon since 1998, uncovering the 16 pyramids, among many other finds, in that time. “So far, we’ve excavated six made out of stone and 10 made out of mud brick,” Welsby said.

The largest pyramid found at Gematon was 10.6 meters (about 35 feet) long on each side and would have risen around 13 m (43 feet) off the ground.

Wealthy and powerful individuals built some of the pyramids, while people of more modest means built the others, Welsby said. “They’re not just the upper-elite burials,” he said.

In fact, not all the tombs in the cemetery have pyramids: Some are buried beneath simple rectangular structures called “mastaba,” whereas others are topped with piles of rocks called “tumuli.” Meanwhile, other tombs have no surviving burial markers at all.

Burial goods

In one tomb, archaeologists discovered an offering table made of tin-bronze. Carved into the tableis a scene showing a prince or priest offering incense and libations to the god Osiris, the ruler of the underworld. Behind Osiris is the goddess Isis, who is also shown pouring libations to Osiris.

Though Osiris and Isis originated in Egypt, they were also venerated in Kush as well as other parts of the ancient world. The offering table “is a royal object,” Welsby said. The person buried with this table “must have been someone very senior in the royal family.”

Most of the tombs had been robbed, to some degree, in ancient or modern times. The only tomb with a pyramid that survived intact held 100 faience beads (faience is a type of ceramic) and the remains of three infants. The fact that the infants were buried without gold treasures may have dissuaded thieves from robbing the tomb, Welsby said.

Kingdom’s end

The Kushite kingdom controlled a vast amount of territory in Sudan between 800 B.C. and the fourth century A.D. There are a number of reasons why the Kushite kingdom collapsed, Welsby said.

One important reason is that the Kushite rulers lost several sources of revenue. A number of trade routes that had kept the Kushite rulers wealthy bypassed the Nile Valley, and instead went through areas that were not part of Kush. As a result, Kush lost out on the economic benefits, and the Kush rulers lost out on revenue opportunities. Additionally, as the economy of the Roman Empire deteriorated, trade between the Kushites and Romans declined, further draining the Kushite rulers of income.

Read more at Discovery News

August Breaks Heat Records Worldwide

Last month was the hottest August in modern history, in the latest sign of an unusually warm year across the world’s land and sea surfaces, US government scientists said Thursday.

Record-breaking warmth was seen across much of South America and parts of Africa, the Middle East, Europe and Asia, said the report by the National Oceanic and Atmospheric Administration.

The most scorching August on the planet in 136 years was also the sixth month this year to have broken a monthly temperature record, putting 2015 on pace to beat 2014 as the warmest year ever, scientists said.

“The world is basically dominated by areas that are record warm or much warmer than average,” said Deke Arndt, monitoring branch chief of NOAA’s National Centers for Environmental Information.

“This applies really to almost every continent, and to large portions of every ocean basin.”

Researchers have calculated it is 97 percent likely that 2015 will be the warmest ever recorded, Arndt said.

Other months this year that have broken records were February, March, May, June, and July, said the NOAA report.

The record continued a worrying trend of warming, which many scientists say is caused by fossil-fuel burning and is exacerbated by the presence of El Nino, which has a warming effect on some parts of the world’s oceans.

Much of August’s warmth was driven by the world’s water.

“Large portions of the seven seas (where temperature records are available) recorded much-warmer-than-average temperatures, with some locations across all oceans experiencing record warmth,” said the report.

Read more at Discovery News

New Horizons Returns Photos of Hazy 'Arctic' Pluto

15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon.

As NASA’s New Horizons mission zipped past Pluto and its system of moons on July 14, it carried out an automated, choreographed routine of rapid data gathering. Looking back at the dwarf planet, after closest approach, with dim sunlight scattering through its hazy atmosphere, the spacecraft glimpsed one of the most stunning photos in space history: Pluto blocking the sun, creating a enigmatic view of the tiny world’s atmospheric halo.

Today, in new images released by the New Horizons team, perhaps an even more captivating scene has been realized. While looking back, shortly after flyby from a distance of 11,000 miles (18,000 kilometers), the New Horizons Ralph/Multispectral Visual Imaging Camera (MVIC) zoomed into a crescent Pluto, through its atmospheric haze, revealing a very “arctic”-looking mountainous landscape.

“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said Alan Stern, New Horizons Principal Investigator, of the Southwest Research Institute, Boulder, Colo. “But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers and plains.”

The haze speaks not of a frozen, static environment — there’s some incredibly dynamic processes going on that we have only just started to fathom.

“In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth,” said Will Grundy, lead of the New Horizons Composition team from Lowell Observatory, Flagstaff, Ariz.

Weather? Yes, weather.

A closer view of the smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous but distended atmosphere.

As we dive into the vast array of observations gradually being streamed back from New Horizons after its close encounter, we’re seeing a complex Pluto that is way more dynamic than we ever dreamed. Before the New Horizons encounter, astronomers knew the dwarf planet possessed some kind of atmosphere, but after seeing Pluto’s surface, evidence is building around this hazy atmosphere cycling exotic ices from the surface and into the atmosphere — akin to Earth’s hydrological cycle.

Read more at Discovery News

Caterpillars Use Their Poop to Trick Plants

Caterpillars that munch on corn leaves have developed a clever way to get the most nutrients from their meals: They use their poop to trick the plants into lowering their defenses.

Scientists at Pennsylvania State University recently discovered that fall armyworm caterpillars (Spodoptera frugiperda) can send chemical signals to plants through their poop, or frass.

"It turns out that the caterpillar frass tricks the plant into sensing that it is being attacked by fungal pathogens," study co-author Dawn Luthe, a professor of plant stress biology at Pennsylvania State University, said in a statement.

Corn plants can deal with only one kind of attack at a time, so while a corn plant is dealing with the perceived "fungal infection," the caterpillar is left to feast on the plant's leaves. Normally, a plant will recognize chemical signatures from insect secretions, which helps the plant know when to raise its defenses. In many cases, this includes producing a biochemical that repels herbivores, such as insects.

But chemical signals from the caterpillar's poop act as crafty diversions, the researchers said.

"The plant perceives that it is being attacked by a pathogen and not an insect, so it turns on its defenses against pathogens, leaving the caterpillar free to continue feeding on the plant," Swayamjit Ray, a doctoral student in plant biology at Penn State and co-author of the paper, said in a statement. "It is an ecological strategy that has been perfected over thousands of years of evolution."

Caterpillars usually feed on the leaves in the confined whorls of corn plants. The critters typically defecate in the crevasses where the leaves meet the stalk, the researchers said.

Scientists studied the biochemical relationship between fall armyworm caterpillar frass and a plant's defensive mechanisms by performing two tests. In the first test, the scientists applied frass extract to the leaves of some corn plants and compared caterpillar growth of those that fed on treated leaves with those that munched on untreated leaves.

The second test involved measuring how frass-treated corn leaves affected defensive performance on plants exposed to a fungal pathogen — in this case, spores of a fungus that causes blight in corn (Cochliobolus heterostrophus). The scientists observed that, initially, proteins in the frass activated an insect defense in the plant, but over time, as the corn plants were exposed to more of the protein, the plants' defenses became altered and instead began to recognize the frass protein as a fungal pathogen instead of an insect waste product. This caused the plant to defend itself against what it saw as a fungal threat instead of an insect threat.

Read more at Discovery News

Half of All Marine Life Lost in Just 40 Years

In just four decades, marine species have declined by 49 percent, according to one of the most extensive surveys of marine life ever compiled.

The “Living Blue Planet Report,” just released by World Wildlife Fund in collaboration with the Zoological Society of London, documents the extraordinary losses, which occurred from 1970 to 2012. Alarmingly, some fish species were found to have declined by almost 75 percent.

The authors of the report attribute the dramatic population drops to human-driven climate change as well as to habitat loss, overexploitation and pollution.

“In less than a human generation, we can see dramatic losses in ocean wildlife -- they have declined by half -- and their habitats have been degraded and destroyed,” Brad Ack, senior vice president for Oceans at WWF, told Discovery News. “Driving all these trends are humans actions: from overfishing and resource depletion, to coastal development and pollution, to the greenhouse gas emissions causing ocean acidification and warming.”

The findings were determined after researchers surveyed more than 10,000 populations of 3,038 marine species, including fish, birds, mammals and reptiles. The report estimates that close to one-third of the world’s fish stocks are overfished, and 1 in 4 species of sharks, rays and skates are threatened with extinction.

Several shark species “have declined dramatically around the world due to overfishing,” and other human-driven causes, confirmed Mahmood Shivji, director of the Guy Harvey Research Institute at Nova Southeastern University, who was not involved with the study.

Yet another key finding from the report is that three-quarters of the world’s coral reefs are currently threatened. At current projected levels of warming and ocean acidification, all coral reefs are projected to be lost by the year 2050.

“Corals are suffering from poor water quality due to deforestation and coastal agriculture, along with increasing fishing pressure on beneficial animals that help them stay healthy, such as reef fish,” Ack said.

"Ocean warming from climate change and ocean acidification from excess carbon absorption significantly threaten reefs over the long-term," Ack said. "At current rates of temperature rise, oceans will become too warm for coral reefs by 2050, resulting in the loss of the world’s most biologically diverse marine ecosystem.”

Currently some coral reefs are able to bounce back from disturbances, such as bleaching events, cyclones and outbreaks of damaging crown-of-thorns starfish. Ocean acidification, however, slows down the ability of corals to recover from these and other threats, adding to the downward trend.

Ack and his colleagues call for immediate measures to curb the decline, such as ending illegal fishing and protecting coral reefs, mangroves and other critical ocean habitats.

This month, world leaders are meeting at a United Nations summit in New York to develop goals for global sustainable development. Ack said the meeting will provide “an opportunity for the international, concerted action we need for ocean conservation.” Ack also said the United Nations Conference on Climate Change, to be held later this year in Paris, was an opportunity to "slash the emissions contributing to the climate and ocean crisis.”

In the report, Marco Lambertini, director-general of WWF International, wrote that “humanity is collectivity mismanaging the ocean to the brink of collapse.”

Read more at Discovery News

Crime and Punishment in the Brain

The punishment should fit the crime. This universal concept underlies any reasonable justice system.

But the foundations of our sense of justice might be more precarious than we might imagine, given that scientists have figured out how to tinker with the part of the brain that deals with punishment.

According to a study published in the journal Neuron, two different regions of the brain separately deal with judgement of guilt or innocence and assessment of punishment. By stimulating the latter, researchers at Vanderbilt University and Harvard University figured out a way to influence penalty decisions.

In experiments involving 66 male and female volunteers, researchers asked study participants to assess a series of scenarios in which a suspect committed a crime, the resulting damage of which ranged from property loss to severe injury and even death.

The part of the brain that deals with punishment decisions is the dorsolateral prefrontal cortex. In half of the study participants, the scientists used repetitive transcranial magnetic stimulation (rTMS), a painless process involving an electromagnet placed on the scalp to temporarily affect cognitive activity, on that region of the brain. The other half of the study participants received a placebo.

What researchers found is that rTMS manipulation changed the way participants assessed penalties for various crimes. While the study’s volunteers universally factored in guilt and the level of harm in a crime in their punishment assessments, those who received rTMS opted for significantly lower punishments for guilty criminals than participants who received the placebo.

“This research gives us deeper insights into how people make decisions relevant to law, and particularly how different parts of the brain contribute to decisions about crime and punishment,” co-author Owen Jones, professor at Vanderbilt and director of the MacArthur Foundation Research Network on Law and Neuroscience, said in a statement.

This study builds on previous work identifying the pathways and cognitive processes of judgement and justice in the brain. Humans are undoubtedly a cooperative species, but our ability to assess guilt and hand out justice to those who don’t go along with social norms is also important to our success as in forming large-scale societies.

A study published in 2011 in the journal PLoS Biology looked at neurological activity during a game involving economic decision-making. One player is asked how to share a fixed sum of money with another player. The second player can either accept the proposal and split the money accordingly, or reject it, and both of the players take home nothing.

If the offer is to share the money equally, the second player always accepts. Any time one player offers an unfair suggestion to his or her counterpart, however, with the split favoring the first player, the second player rejects the offer half of the time, even though that means the second player lost money, too. This inequitable offer triggers an automatic response in the amygdala of the brain, which deals with fear and anger and helps to explain the reaction of the second player to a sense of unfairness.

Read more at Discovery News

Saturn Geyser Moon Hiding Global Ocean

Ever since NASA’s Cassini spacecraft returned startling pictures of geyers shooting into space from Enceladus, scientists have wondered just how much water is buried beneath the moon’s icy surface.

“We’ve known for some time that a liquid layer is present, but not how extensive it is. Well now we do,” said Cassini imaging team chief Carolyn Porco, with the Space Science Institute in Boulder, Colorado.

By measuring tiny wobbles in Enceladus’ orbit, scientists have figured out that Enceladus has a global ocean.

“How did they do it? By looking for a libration … a small, cyclical, back-and-forth deviation from uniform rotation … and finding that it is present and much too large to be a libration of the entire body. The conclusion: It is a libration in the thin, outer ice shell only, indicating that ice shell and rocky core are decoupled and separated by a liquid layer,” Porco posted on Facebook.

Previously, scientists suspected that Enceladus had some pockets of water beneath its surface, but no evidence the ocean may be global, similar to what is believed to exist within Jupiter’s moon Europa.

The first hint of widespread subsurface water came from gravity measurements taken in 2013 and 2014 as Cassini passed close to Enceladus’ south pole.

That data provided evidence of a south polar sea, about 22 miles below the surface and about six miles thick, and perhaps connected to a thinner global ocean, Porco said.

Now an independent analysis, matching Enceladus’ slight wobble with computer models, confirms the theory.

The computer models show that a layer of liquid must separate the moon’s solid core from its icy surface, scientists wrote in an article to be published in the journal Icarus.

“If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be,” Cassini scientist Matthew Tiscareno, with the SETI Institute in Mountain View, California, said in a statement.

“This proves that there must be a global layer of liquid separating the surface from the core,” he said.

“This was a hard problem that required years of observations and calculations … but we are confident we finally got it right,” added Cassini scientist Peter Thomas, with Cornell University in New York.

How the ocean has managed to remain liquid is not yet known. One idea is that tidal forces from Saturn’s gravity could be generating much more heat within Enceladus than previously thought.

Cassini is scheduled to pass right through an active plume on Enceladus on Oct. 28, coming as close as 30 miles from the moon’s surface.

Read more at Discovery News

Blind Cave Fish Traded Eyesight for Energy

At first glance, the blind cave fish is an example of evolution seemingly moving backward.

Over time, a handful of Mexican tetra (Astyanax mexicanus) living at deep depths have gradually lost not only their eyesight, but also their eyes, while their surface-dwelling counterparts have maintained their vision. Dubbed the "blind cave fish", the eyeless creature also lost much of its pigmentation, growing to sport a body of fleshy pink scales.

According to new research out of Sweden's Lund University, however, the blind cave fish's lost vision is actually a major step forward in adapting the fish to its new environment.

Researchers conclude that a highly developed visual system can suck up to 15% of an animal's "total energy budget". For a fish living at deep, dark depths with an irregular food supply, that expenditure simply isn't worth it.

"This is a tremendously high cost! Over evolution, this morph lost both eyes and visual cortex, without a doubt because of the unsustainable energy cost of maintaining a sensory system that no longer had any significance", study lead author Damian Moran explains in a news release.

Instead, the blind cave fish has come to rely upon a finely tuned sense of smell and a keen sensitivity to changes in water pressure.

Scientists revealed last year that the fish has also ditched its circadian rhythm as an energy-saving measure.

"These cave fish are living in an environment without light, without the circadian presence of food or predators, they've got nothing to get ready for, so it looks like they've just chopped away this increase in anticipation for the day," Plant and Food Research New Zealand scientist Dr. Damian Moran explained when his research was published.

Read more at Discovery News

Antarctica Would Thaw If All Fossil Fuels Are Burned

This doesn’t happen often, but title of the study itself is more mind-blowing than any lead we could write. So here it is:

“Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet.”

That’s right. If every bit of the oil, coal and natural gas that’s believed to be in the ground were used up over the next 500 years, we would emit about 10,000 gigatons of carbon. That would cause the southernmost continent — which became frozen about 12.8 million years ago — to thaw out like a TV dinner in your microwave.

“Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources,” concluded the study in Science Advances, whose lead author is Stanford University researcher Ken Caldeira.

Unlike the frost on your Salisbury steak and mashed potatoes, we’re talking about a whole lot of H20. According to the National Snow and Ice Center, the Antarctic ice sheet extends almost for 5.4 million square miles, roughly the area of the lower 48 state and Mexico combined. It contains 7.2 million cubic miles of ice.

Melt it all, and you’d raise global sea level by about 200 feet.

If there’s a saving grace, it’s that such a complete thaw would take place over thousands of years, long after humanity’s orgy of fossil fuel consumption had concluded. That why New York Times environmental reporter Andrew Revkin describes the study as “far more a thought experiment than a prediction,” and notes that even China, a voracious consumer of coal, is aggressively working to stop the increase in its carbon output by developing more solar and wind energy.

But even if humans ultimately don’t melt all of the Antarctic ice covering, we’re already done a lot of damage to it. According to NSIC, Antarctica’s land ice hasn’t been melting as rapidly as the Greenland ice sheet in the Northern Hemisphere, which combines with it to lock up about 99 percent of the freshwater ice on the planet. But the West Antarctic Ice Sheet, which contains enough ice to raise global sea levels by four feet, is now considered unstable.

Read more at Discovery News

Longest Continental Volcanic Chain Found In Australia

The world's longest chain of continental volcanoes has been discovered stretching for more than 1,200 miles along eastern Australia.

The ancient volcanic chain, reported in the journal Nature, runs from Cape Hillsborough on the central Queensland coast, south-west through central New South Wales to Cosgrove in Victoria.

"This volcanic chain was created over the past 33 million years, as Australia moved north-northeast over a mantle plume hotspot which we believe is now located in Bass Strait," said the study's lead author, Dr Rhodri Davies of the Australian National University.

"This track, which we've named the Cosgrove hotspot track [after an extinct Victorian volcano in the chain], is nearly three times as long as the famous Yellowstone hotspot tracks on the North American continent."

This kind of volcanic activity is surprising because it occurs away from tectonic plate boundaries where most volcanoes are found.

These hotspots are thought to form above mantle plumes, narrow upwellings of hot rock that originate at Earth's core-mantle boundary almost 1,800 miles below the surface. A volcano chain is created as the tectonic plate moves over the hotspot.

The newly identified volcanic chain is the most westerly of three major volcanic chains running along eastern Australia.

The authors examined 15 extinct volcanoes in eastern Australia that had been known about for quite some time and appeared to follow a generally similar track.

"The volcanoes in central Queensland showed an age progression, so they got younger towards the south, and so too did those in New South Wales and Victoria," Davies said.

The researchers looked at the movement of the Australian tectonic plate.

"Australia is actually the fastest moving continent on Earth, moving towards Indonesia at around seven centimetres per year," Davies said.

The researchers found the chain of now-extinct volcanoes in Queensland, New South Wales and Victoria had all passed over the same fixed mantle plume hotspot as the Australian continental plate tracked north-northeast.

"We showed that these volcanoes are surface manifestations of the same mantle plume," Davies said.

"However, the two groups of volcanoes were geochemically very distinct from each other and were separated by a gap of 700 kilometres, so no-one ever put these two volcanic chains together."

Chain helps give better understanding of volcanism

Davies and colleagues used seismology to map the thickness of Earth's crust and mantle -- known as the lithosphere -- that lies under eastern Australia.

They found volcanoes in central Queensland erupted through lithospheres about 50 miles thick while those in New South Wales and Victoria had melted through lithospheres about 62 miles thick.

But the gap between the Queensland volcanoes and those in New South Wales and Victoria occurred because the lithosphere in this region was at least 93 miles thick.

"So the mantle plume can't melt through in those regions, so there's no volcanoes on the surface," Davies said.

The thickness of the lithosphere also explained differences in the chemical composition of the volcanic rocks at different locations.

"If you take a mantle plume of a specific temperature and raise that to a depth of say 130 kilometres below the surface, specific minerals from the surrounding rock will enter that melt," Dr Davies said.

"And if the plume reaches shallower depths of say 100 kilometres, additional elements will enter the melt, changing the chemical composition.

"By looking at this chain of volcanoes in Australia and understanding the composition of the volcanic rock and how they evolved with time, we will understand volcanism on other continents and through earlier periods in Earth's history which is still poorly understood."

Read more at Discovery News

Paleolithic Hunter-Gatherers Loved Oatmeal Too

Some like it hot, some like it cold, and it looks like they probably liked it about 32,000 years ago.

An ancient grinding stone found in the Grotta Paglicci, Apulia, in southern Italy, has hit the news after scientists discovered that some of the debris on the stone turns out to be none other than oatmeal. The stone harkens back to the Gravettian era, a late Paleolithic culture, known for its tool making. It was recovered in the 1950s, but it wasn’t until recently that Marta Mariotti Lippi and team at the University of Florence in Italy studied the debris and found the oat fragments.

The team determined that the Gravettian people heated the grains before grinding them with the stone in order to preserve and prep them for processing. The resulting powder was then made into bread and oatmeal.

The Grotta Paglicci, Apulia served as home to ancient hunter-gatherer cultures anywhere from 34,000-32,000 years ago, and has produced artifacts that include mural paintings with animals and etchings on bones. As for the stone, Lippi says the team intends to continue studying the debris to find out what else prehistoric cultures dined on.

Matt Pope, an archaeologist with University College London, told Herald Scotland, “There is a relationship there to be explored between diet, experimentation with processing plant food and cultural sophistication. We’ve had evidence of the processing of roots and cattails, but here we’ve got a grain, and a grain that we’re very familiar with.”

From Discovery News

Mercury's Speedy Spin Hints at Planet's Insides

Mercury is a spinning faster than scientists had thought: New research shows that the planet completes a rotation on its axis roughly 9 seconds more quickly than scientists previously charted — and that data will help scientists understand more about the planet's molten core.

Mercury is a rocky planet only slightly larger than Earth's moon. Based on the data collected from NASA's MESSENGER spacecraft, scientists think most of Mercury contains a molten core that takes up 70 percent of the planet's mass. The newly measured rotation rate can be used to help calculate the proportions of solid and liquid within, even as researchers begin to understand its cause.

"One possible explanation for Mercury's faster rotation is that Jupiter influences its orbit," study participant Alexander Stark, of the German Space Agency (DLR) Institute of Planetary Research, said in a statement. "As a result, its distance from the sun varies, which, in turn, affects the planet's rotation speed."

Mercury is the closest planet to the sun. Because of tidal forces exerted by the star's gravity, Mercury has a 59-day rotation period that represents a 3:2 ratio with its 88-day orbit around the sun — for every three times it rotates, it orbits the sun twice. This ratio is unique among planets in the solar system.

MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) was the first orbital mission around Mercury; after flying by the planet a couple of times, it remained there taking measurements between 2011 and 2015.

While it was there, MESSENGER was also the first spacecraft to detect slight irregularities as Mercury moved around its orbit. By measuring the irregularities, scientists can deduce the size and density of the core, as well as map the planet more accurately.

Read more at Discovery News

Magellanic Clouds Captured by Planck Satellite

It may look like a close-up of a Vincent van Gogh painting, but this is a portrait of the Large and Small Magellanic Clouds as seen through the eyes of the European Space Agency’s Planck satellite.

The Magellanic Clouds, which can only be seen from the southern hemisphere, are two of our nearest neighbors.

The Large Magellanic Cloud is the big red and orange blob near the center of the image, while the Small Magellanic Cloud is the triangular-shaped object in the lower left.

The Planck spacecraft, which operated from 2009 to 2013, studied the sky in microwave and infrared wavelengths.

As the probe examined the cosmic microwave background radiation, which is the left over heat from the big bang, it saw the dust between the stars in the Magellanic Clouds and virtually anything else that shone at these frequencies.

This includes many other galaxies, both near and far, as well as interstellar material in the Milky Way.

Interstellar dust in a large star-forming region of the Milky Way known as the Chameleon constellation, can be seen as the mixture of red, orange and yellow clouds in the upper part of the image.

A large dusty filament can also be seen stretching from the dense clouds of Chameleon, in the upper left, towards the opposite corner of the image.

Although it appears to stretch between the two Magellanic Clouds, it is actually part of our own galaxy, a mere 300 light-years away and aligned with our galaxy’s magnetic field.

Read more at Discovery News

Medieval Bones Burst From Ground When Tree Topples

The skeleton of a Medieval teenager has literally burst from the ground when storms in Sligo, Ireland, blew over a massive, centuries-old beech tree, revealing bones entangled in the roots.

“The upper part of the skeleton was raised into the air trapped within the root system,” archaeologists Marion Dowd of Sligo-Leitrim Archaeological Services, said in a statement.

“The lower leg bones, however, remained intact in the ground. Effectively as the tree collapsed, it snapped the skeleton in two,” Dowd said.

Analysis of the bones and radiocarbon dating suggest the remains belonged to a 17-20-year-old man who lived in the early Medieval period, between 1030 and 1200 A.D.

At over 5′ 10″ in height, the teenager was taller than the average Medieval person. He was almost certainly from a local Gaelic family and is believed to have toiled in physical labor from a young age, as suggested by mild spinal joint disease in the skeleton.

The young man died a violent death, according to archaeologists. Two stab wounds, probably inflicted by a knife, are clearly visible to the ribs and the left hand.

“Whether he died in battle or was killed during a personal dispute, we will never know for sure,” Dowd said.

The man was given a Christian burial. However, it is not known whether he was interred in a graveyard or in an isolated burial.

“While historical records state the presence of a church and graveyard in the area, no above-ground trace survives and no other skeletons were encountered during the excavations,” Sligo-Leitrim Archaeological Services said.

Further analysis of the remains is currently underway.

From Discovery News

Oldest, Longest Ancient Egyptian Leather Manuscript Found

The oldest Egyptian leather manuscript has been found in the shelves of the Egyptian museum in Cairo, where it was stored and forgotten for more than 70 years.

Dating from the late Old Kingdom to the early Middle Kingdom (2300-2000 B.C.), the roll measures about 2.5 meters(8.2 feet) and is filled with texts and colorful drawings of the finest quality.

“Taking into account that it was written on both sides, we have more than 5 meters (16.4 feet) of texts and drawings, making this the longest leather roll from ancient Egypt,” Wael Sherbiny, the Belgium-based independent scholar who made the finding, told Discovery News.

The first Egyptian to obtain his PhD in Egyptology in 2008 from the Leuven University in Belgium, Sherbiny specializes in the ancient Egyptian religious texts and is preparing the full publication of the unique leather roll.

He announced the finding at the recent International Congress of Egyptologists in Florence.

Nothing is known about the manuscript’s origins. The French Institute of Oriental Archaeology in Cairo bought it from a local antiquities dealer sometime after the WWI. Later it was donated to the Cairo Museum, where it was unrolled shortly before the outbreak of the WWII.

“Since then it was stored in the museum and fell completely into oblivion,” Sherbiny said.

Basically a portable religious manuscript, the more than 4,000-year-old roll, contains depictions of divine and supernatural beings which predate the famous drawings found in the Book of the Dead manuscripts and the so-called Netherworld Books from the New Kingdom onwards (1550 B.C. onwards).

Religious spells, formulated in the first person singular, also abound there.

“They were likely recited by a priest,” Sherbiny said.

It is known that priests used to carry leather rolls to reference while reciting sacred texts during religious rituals.

Only six other portable manuscripts have survived from ancient Egypt and could possibly share a close date with the Cairo leather roll. All of them are papyri.

“Leather was considered a very precious writing material in ancient Egypt. It was the principal writing medium to record holy texts and great historic events as it was more practical than papyrus due to its flexibility and durability,” Sherbiny said.

Such prestigious leather rolls, kept in the libraries and archives of temples, were also used as master copies from which cheaper copies were reproduced on papyrus. While papyri were preserved by Egypt’s dry climate, leather objects quickly perished.

The Cairo roll was no exception: part of it was fragmented into very tiny pieces. Like in a jigsaw puzzle, Sherbiny pieced them all together.

The pieces formed a large pictorial-textual segment from the so-called Book of Two Ways, which is an illustrated composition containing temple rituals later adapted for the funerary use.

This composition is known to Egyptologists as it occurs on the floorboard of Middle Kingdom coffins (2055-1650 B.C.) from the necropolis of Hermopolis in Upper Egypt.

“Amazingly, the roll offers an even more detailed iconography than the Hermopolitan coffins in terms of texts and drawings,” Sherbiny said.

Read more at Discovery News

Calif. Firefighters Battle to Save World's Largest Trees

Several record-breaking and historic trees are in the path of one of three massive wildfires that are ravaging central and northern California.

The trees in harm’s way include “General Grant,” a giant sequoia that, at over 260 feet tall, is one of the top three largest trees in the world; and Boole Tree, which is the world’s sixth largest giant sequoia.

The Rough Fire surrounding the trees has burned 135,000 acres and remains less than 50 percent contained.

A webcam captured the Rough Fire burning toward the Sierras:

So far, the legendary trees have been spared, thanks to firefighters who have been battling the blaze 24/7.

“It’s getting better, firefighter Luis Magana told The Sacramento Bee. He added that on Friday, “it was raining down ash,” but that has turned into more of a light ash drizzle now.

Underbrush was cleared in a grove near the trees, and prescribed burns have kept the fire from overrunning the break around General Grant Grove, a section of the greater Kings Canyon National Park where the historic trees are.

The General Grant Tree is over 3000 years old, and is known as the national Christmas Tree of the U.S. The region is also home to the fabled Chicago Stump, which is what’s left of the 95-foot-wide General Noble Tree that was cut down in 1892 to create an exhibit for the following year. It was one of the largest trees to have ever been cut down.

Paul Garnier, a spokesman for the Rough Fire’s incident management team, told the Los Angeles Times that a bark and beetle infestation previously killed multiple pine trees in the area, adding fuel to the already drought-ravaged landscape.

Garnier said that crews hand-cut lines around the historic trees — even the Chicago Stump — and ran designated hose lines to them. The trees, surrounded by flames, were then blanketed with an aboveground sprinkler system.

Wildfires are a part of a healthy ecosystem, he said, and can help some trees germinate.

“It really is more that man has come into this wild space so we have to be involved and make sure people and property are protected,” he added.

Read more at Discovery News

North American Continent Isn't as Solid as You Might Think

You’ve heard the phrase “solid as a rock.” But it turns out that at least as far as North America is concerned, the rock isn’t necessarily so solid.

In a study published in Nature Geoscience, scientists from the GFZ German Research Centre for Geosciences reveal that North America’s ancient rocky core actually is extremely deformed, and that its root actually shifts away from the center by nearly 530 miles to the west-southwest. Our continent in some ways resembles a person with scoliosis, a crooked spine.

That shift in the root also runs counter to the previous assumption by scientists that the continents’ rocky cores, called cratons, have been pretty much stable for the past 2.5 to 3.8 billion years, even as the continents themselves break up, drift apart and are pushed back together. The cratons are among the oldest geological features on the planet.

“We combined and analyzed several data sets from Earth’s gravity field, topography, seismology and crustal structure and constructed a three dimensional density model of the composition of the lithosphere below North America,” GFZ scientist Mikhail Kaban explained in a press release. ”It became apparent that the lower part of the cratonic root was shifted by about 850 kilometers (528.17 miles).”

But you may be wondering how North America’s craton got so messed up. The German scientists, who modeled the flow of the Earth’s semi-molten mantle beneath the continent, say that the hot material flows westward at a velocity of about 4 millimeters — about 0.16 of an inch–per year. That may not seem like a lot, but it’s enough to put the continental core out of kilter.

Read more at Discovery News

Uniting classical and quantum mechanics: Breakthrough observation of Mott transition in a superconductor

An international team of researchers, including the MESA+ Institute for Nanotechnology at the University of Twente in the Netherlands and the U.S. Department of Energy's Argonne National Laboratory, announced today in Science the observation of a dynamic Mott transition in a superconductor.

The discovery experimentally connects the worlds of classical and quantum mechanics and illuminates the mysterious nature of the Mott transition. It also could shed light on non-equilibrium physics, which is poorly understood but governs most of what occurs in our world. The finding may also represent a step towards more efficient electronics based on the Mott transition.

Since its foundations were laid in the early part of the 20th century, scientists have been trying to reconcile quantum mechanics with the rules of classical or Newtonian physics (like how you describe the path of an apple thrown into the air--or dropped from a tree). Physicists have made strides in linking the two approaches, but experiments that connect the two are still few and far between; physics phenomena are usually classified as either quantum or classical, but not both.

One system that unites the two is found in superconductors, certain materials that conduct electricity perfectly when cooled to very low temperatures. Magnetic fields penetrate the superconducting material in the form of tiny filaments called vortices, which control the electronic and magnetic properties of the materials.

These vortices display both classical and quantum properties, which led researchers to study them for access to one of the most enigmatic phenomena of modern condensed matter physics: the Mott insulator-to-metal transition.

The Mott transition occurs in certain materials that according to textbook quantum mechanics should be metals, but in reality turn insulators. A complex phenomenon controlled by the interactions of many quantum particles, the Mott transition remains mysterious--even whether or not it's a classical or quantum phenomenon is not quite clear. Moreover, scientists have never directly observed a dynamic Mott transition, in which a phase transition from an insulating to a metallic state is induced by driving an electrical current through the system; the disorder inherent in real systems disguises Mott properties.

At the University of Twente, researchers built a system containing 90,000 superconducting niobium nano-sized islands on top of a gold film. In this configuration, the vortices find it energetically easiest to settle into energy dimples in an arrangement like an egg crate--and make the material act as a Mott insulator, since the vortices won't move if the applied electric current is small.

When they applied a large enough electric current, however, the scientists saw a dynamic Mott transition as the system flipped to become a conducting metal; the properties of the material had changed as the current pushed it out of equilibrium.

The vortex system behaved exactly like an electronic Mott transition driven by temperature, said Valerii Vinokur, an Argonne Distinguished Fellow and corresponding author on the study. He and study co-author Tatyana Baturina, then at Argonne, analyzed the data and recognized the Mott behavior.

"This experimentally materializes the correspondence between quantum and classical physics," Vinokur said.

"We can controllably induce a phase transition between a state of locked vortices to itinerant vortices by applying an electric current to the system," said Hans Hilgenkamp, head of the University of Twente research group. "Studying these phase transitions in our artificial systems is interesting in its own right, but may also provide further insight in the electronic transitions in real materials."

The system could further provide scientists with insight into two categories of physics that have been hard to understand: many-body systems and out-of-equilibrium systems.

"This is a classical system that which is easy to experiment with and provides what looks like access to very complicated many-body systems," said Vinokur. "It looks a bit like magic."

As the name implies, many-body problems involve a large number of particles interacting; with current theory they are very difficult to model or understand.

"Furthermore, this system will be key to building a general understanding of out-of-equilibrium physics, which would be a major breakthrough in physics," Vinokur said.

The Department of Energy named five great basic energy scientific challenges of our time; one of them is understanding and controlling out-of-equilibrium phenomena. Equilibrium systems--where there's no energy moving around--are now understood quite well. But nearly everything in our lives involves energy flow, from photosynthesis to digestion to tropical cyclones, and we don't yet have the physics to describe it well. Scientists think a better understanding could lead to huge improvements in energy capture, batteries and energy storage, electronics and more.

Read more at Science Daily

Stellar discovery: Massive binary star with unique properties

PhD candidate Matt Shultz has discovered the first massive binary star, epsilon Lupi, in which both stars have magnetic fields. A binary star is a star system consisting of two or more stars, orbiting around their common centre of mass.

For the past few years, the BinaMIcS (Binarity and Magnetic Interactions in various classes of Stars) collaboration, formed to study the magnetic properties of close binaries, has been trying to find such an object. They have now discovered one using the Canada-France-Hawaii Telescope.

"The origin of magnetism amongst massive stars is something of a mystery," says Mr. Shultz (Physics, Engineering Physics and Astronomy), "and this discovery may help to shed some light on the question of why these stars have magnetic fields."

In cool stars, such as the Sun, magnetic fields are generated by a convection in the outer portion of the star. However, there is no convection in the outer layers of massive star, so there is no support for a magnetic dynamo. Nevertheless, approximately 10 per cent of massive stars have strong magnetic fields.

Two explanations have been proposed for the origin of massive star magnetic fields, both variants on the idea of a so-called "fossil" magnetic field, which is generated at some point in the star's past and then locked in to the star's outer portion.

The first hypothesis is that the magnetic field is generated while the star is being formed; the second is that the magnetic field originates in dynamos driven by the violent mixing of stellar plasma when the two stars in a close binary merge.

"This discovery doesn't change the basic statistics that the BinaMIcS collaboration has assembled," says Mr. Shultz, "and we still don't know why there are so few magnetic, massive stars in close binaries."

The research shows the strengths of the magnetic fields are similar in the two stars, however, their magnetic axes are anti-aligned, with the south pole of one star pointing in approximately the same direction as the north pole of the other.

Read more at Science Daily