Sep 5, 2015

Solar water-splitting technology developed

Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules.

The technology, which is described online in the American Chemical Society journal Nano Letters, relies on a configuration of light-activated gold nanoparticles that harvest sunlight and transfer solar energy to highly excited electrons, which scientists sometimes refer to as "hot electrons."

"Hot electrons have the potential to drive very useful chemical reactions, but they decay very rapidly, and people have struggled to harness their energy," said lead researcher Isabell Thomann, assistant professor of electrical and computer engineering and of chemistry and materials science and nanoengineering at Rice. "For example, most of the energy losses in today's best photovoltaic solar panels are the result of hot electrons that cool within a few trillionths of a second and release their energy as wasted heat."

Capturing these high-energy electrons before they cool could allow solar-energy providers to significantly increase their solar-to-electric power-conversion efficiencies and meet a national goal of reducing the cost of solar electricity.

In the light-activated nanoparticles studied by Thomann and colleagues at Rice's Laboratory for Nanophotonics (LANP), light is captured and converted into plasmons, waves of electrons that flow like a fluid across the metal surface of the nanoparticles. Plasmons are high-energy states that are short-lived, but researchers at Rice and elsewhere have found ways to capture plasmonic energy and convert it into useful heat or light. Plasmonic nanoparticles also offer one of the most promising means of harnessing the power of hot electrons, and LANP researchers have made progress toward that goal in several recent studies.

Thomann and her team, graduate students Hossein Robatjazi, Shah Mohammad Bahauddin and Chloe Doiron, created a system that uses the energy from hot electrons to split molecules of water into oxygen and hydrogen. That's important because oxygen and hydrogen are the feedstocks for fuel cells, electrochemical devices that produce electricity cleanly and efficiently.

To use the hot electrons, Thomann's team first had to find a way to separate them from their corresponding "electron holes," the low-energy states that the hot electrons vacated when they received their plasmonic jolt of energy. One reason hot electrons are so short-lived is that they have a strong tendency to release their newfound energy and revert to their low-energy state. The only way to avoid this is to engineer a system where the hot electrons and electron holes are rapidly separated from one another. The standard way for electrical engineers to do this is to drive the hot electrons over an energy barrier that acts like a one-way valve. Thomann said this approach has inherent inefficiencies, but it is attractive to engineers because it uses well-understood technology called Schottky barriers, a tried-and-true component of electrical engineering.

"Because of the inherent inefficiencies, we wanted to find a new approach to the problem," Thomann said. "We took an unconventional approach: Rather than driving off the hot electrons, we designed a system to carry away the electron holes. In effect, our setup acts like a sieve or a membrane. The holes can pass through, but the hot electrons cannot, so they are left available on the surface of the plasmonic nanoparticles."

The setup features three layers of materials. The bottom layer is a thin sheet of shiny aluminum. This layer is covered with a thin coating of transparent nickel-oxide, and scattered atop this is a collection of plasmonic gold nanoparticles -- puck-shaped disks about 10 to 30 nanometers in diameter.

Read more at Science Daily

Hubble survey unlocks clues to star birth in neighboring galaxy

In a survey of NASA's Hubble Space Telescope images of 2,753 young, blue star clusters in the neighboring Andromeda galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass.

By nailing down what percentage of stars have a particular mass within a cluster, or the Initial Mass Function (IMF), scientists can better interpret the light from distant galaxies and understand the formation history of stars in our universe.

The intensive survey, assembled from 414 Hubble mosaic photographs of M31, was a unique collaboration between astronomers and "citizen scientists," volunteers who provided invaluable help in analyzing the mountain of data from Hubble.

"Given the sheer volume of Hubble images, our study of the IMF would not have been possible without the help of citizen scientists," said Daniel Weisz of the University of Washington in Seattle. Weisz is lead author on a paper that appeared in the June 20 issue of The Astrophysical Journal.

Measuring the IMF was the primary driver behind Hubble's ambitious panoramic survey of our neighboring galaxy, called the Panchromatic Hubble Andromeda Treasury (PHAT) program. Nearly 8,000 images of 117 million stars in the galaxy's disk were obtained from viewing Andromeda in near-ultraviolet, visible, and near-infrared wavelengths.

Stars are born when a giant cloud of molecular hydrogen, dust, and trace elements collapses. The cloud fragments into small knots of material that each precipitate hundreds of stars. The stars are not all created equally: their masses can range from 1/12th to a couple hundred times the mass of our sun.

Prior to Hubble's landmark survey of the star-filled disk of M31, astronomers only had IMF measurements made in the local stellar neighborhood within our own galaxy. But Hubble's bird's-eye view of M31 allowed astronomers to compare the IMF among a larger-than-ever sampling of star clusters that are all at approximately the same distance from Earth, 2.5 million light-years. The survey is diverse because the clusters are scattered across the galaxy; they vary in mass by factors of 10, and they range in age from 4 million to 24 million years old.

To the researchers' surprise, the IMF was very similar among all the clusters surveyed. Nature apparently cooks up stars like batches of cookies, with a consistent distribution from massive blue supergiant stars to small red dwarf stars. "It's hard to imagine that the IMF is so uniform across our neighboring galaxy given the complex physics of star formation," Weisz said.

Curiously, the brightest and most massive stars in these clusters are 25 percent less abundant than predicted by previous research. Astronomers use the light from these brightest stars to weigh distant star clusters and galaxies and to measure how rapidly the clusters are forming stars. This result suggests that mass estimates using previous work were too low because they assumed that there were too few faint, low-mass stars forming along with the bright, massive stars.

This evidence also implies that the early universe did not have as many heavy elements for making planets, because there would be fewer supernovae from massive stars to manufacture heavy elements for planet building. It is critical to know the star-formation rate in the early universe -- about 10 billion years ago -- because that was the time when most of the universe's stars formed.

Read more at Science Daily

Sep 4, 2015

Kestrel Mummy Hints at Raptor Breeding in Ancient Egypt

The last meal of a mummified kestrel has much to tell scientists about how the ancient Egyptians handled raptors, and why so many mummies of the birds of prey have been found.

So suggests a study just published in the Journal of Archaeological Science, which presents 3D imaging evidence and analysis of a European kestrel (Falco tinnunculus) mummy.

Researchers from the American University in Cairo, Stellenbosch University and the Stellenbosch Institute for Advanced Studies say the bird died from being forced to eat too much: Its stomach contained evidence of a house mouse on which the bird had likely choked to death.

The raptor also appeared to have eaten another mouse on the same day, and parts of a small sparrow were also found. And, the scientists wrote, "there is no indication that it was deliberately killed as there is no clear separation of, or broken, vertebrae."

The researchers say the evidence of such force feeding points to a raptor breeding program, one that gave the Egyptians a steady supply of the animals to offer up to the sun god Re, with which raptors were closely identified in ancient Egypt

"The idea of birds of prey being bred to the extent of being kept and force-fed is new," said Salima Ikram, in a press release.

"Until now," said Ikram, professor of Egyptology at the American University in Cairo and lead author of the study, "the sheer number of raptor mummies had been a mystery. Did they catch or trap them and kill them, raid nests, or find them dead? Our results explain why they had so many: We now think it was because of active breeding."

What isn't new is the idea of animal mummies. They were commonly used in religious ceremonies from around 600 B.C. to 250 A.D., the researchers write, and many such offerings have been recovered.

Egyptians typically gutted ceremonial animals prior to mummification, but this bird, supplied by South Africa's Iziko Museums, had not received that treatment. That left its last meal available for examination.

Read more at Discovery News

Summer Sea Ice Likely to Drop to 4th Lowest on Record

The shell of ice that covers the Arctic Ocean is nearing its yearly low point and projections suggest that it will be among the four lowest summer minimums on record. If melt rates are speedy enough, there’s a chance it could even take the number two spot, forecasters said Wednesday, as the ice continues its decades-long, warming-driven decline.

The sea ice that caps the Arctic Ocean naturally waxes and wanes with the seasons, reaching its maximum area at the end of winter, before the reemergence of the sun in spring starts off the melt season. Sea ice area, or extent, usually hits its annual minimum in mid- to late-September.

The warming of the planet from the human-driven accumulation of heat-trapping greenhouse gases in the atmosphere is acting over this cycle, leading to overall declines in sea ice, with a particularly pronounced drop-off in summer numbers. Those declines range from 10 to 15 percent per decade depending on the season.

The melt of sea ice driven by warming, which also leads to a thinning of the ice, has major implications for the Arctic area. Wildlife like polar bears and walruses that depend on the sea ice can be hampered in their pursuit of prey, and the livelihoods of indigenous communities can be threatened.

Sustained melt has also opened the region to more ship traffic and oil exploration, which pits economic opportunity against potential ecological effects.

This year’s summer melt has seen periods where melt surges ahead, followed by weeks where it levels off. The rate of melt can be affected by the weather in the region, with winds pushing sea ice around and high pressure systems bringing sunny weather that helps fuel melt.

Throughout August, sea ice melted at a steady clip, after a rapid decline in late July. While it’s uncertain exactly where the summer minimum will end up in a few weeks, forecasters can use the rates of decline from previous years (as well as those of recent weeks) to estimate a range of possibilities.

Even if there were no further loss of ice this year, the amount of ice present right now would still replace last year as the sixth lowest extent on record. But since there will be additional melting, the most likely scenarios are for the fourth or third lowest extents, in that order, forecasters with the National Snow and Ice Data Center in Boulder, Colo., have said.

There is a small chance that this year could snag the number two spot from 2007, if melt follows the fastest rate of recent years, which it did for the last 10 days of August, the NSIDC noted.

The lowest extent on record came during the remarkable summer melt season of 2012, fueled in part by summer storms that moved ice into warm waters.

Nearly all sectors of the Arctic Ocean have had below average sea ice concentrations, with the exceptions of Baffin and Hudson bays (both to the north of Canada), where some higher concentrations are sitting in sheltered coastal areas, the NSIDC said.

Read more at Discovery News

Particle Collider Spits Out Tiny Drops of Primordial Goo

A US-based laboratory has produced tiny droplets of a state of matter that existed in the first few milliseconds after the Big Bang after slamming particles together at close to the speed of light.

The matter, known as a quark-gluon plasma (or QGP), is predicted to exist when temperatures and densities are so extreme that regular matter cannot exist. Instead, a “perfect liquid” exists for a short time before it cools and condenses into the regular stuff that forms the building blocks of matter.

Although physicists have announced the detection of this exotic state of matter before, new results from the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, in Upton, New York, appear to show the tiniest droplets of quark-gluon plasma appear, in a specific pattern, after colliding helium-3 nuclei with gold ions.

“These tiny droplets of quark-gluon plasma were at first an intriguing surprise,” said Berndt Mueller, Associate Laboratory Director for Nuclear and Particle Physics at Brookhaven, in a statement. “Physicists initially thought that only the nuclei of large atoms such as gold would have enough matter and energy to set free the quark and gluon building blocks that make up protons and neutrons. But the flow patterns detected by RHIC’s PHENIX (Pioneering High Energy Nuclear Interaction eXperiment) collaboration in collisions of helium-3 nuclei with gold ions now confirm that these smaller particles are creating tiny samples of perfect liquid QGP.”

Experiments at RHIC and the Large Hadron Collider (LHC), near Geneva, Switzerland, have been chasing the formation of this primordial state of matter for some time. In 2013, LHC physicists also announced the discovery of these quark-gluon plasma droplets after slamming protons into lead ions.

But this is the first time that helium-3, a light ion, has been collided with heavy ions (gold), producing the signature of quark-gluon plasma. This indicates that the stuff can be produced at lower energies, opening a fascinating opportunity to study this quantum ‘goo’ that last existed in nature in the first moments of the birth of our universe, some 13.8 billion years ago.

And the initial results seem to show these tiny droplets act as predicted — like a perfect, frictionless liquid.

“The idea that collisions of small particles with larger nuclei might create minute droplets of primordial quark-gluon plasma has guided a series of experiments to test this idea and alternative explanations, and stimulated a rich debate about the implications of these findings,” added physicist Jamie Nagle, of the University of Colorado and co-spokesperson of the PHENIX collaboration at RHIC. “These experiments are revealing the key elements required for creating quark-gluon plasma and could also offer insight into the initial state characteristics of the colliding particles.”

The discovery of a “perfect liquid” stemming from the collision of heavy ions in RHIC was first announced in 2005. Post-collision analysis seemed to show a collective “flow” of matter erupt from the intense flash of energy. This finding was inconsistent with the uniform expansion of a gaseous state of matter, so high-energy physicists realized that they were looking at a new state of matter, composed of quarks (the subatomic building blocks of protons and neutrons) and gluons (a particle, or “boson”, that carries the strong nuclear force) that acts as a perfect liquid. Since these initial discoveries, physicists have refined their accelerator experiments, colliding different ions together, producing different configurations of the quark-gluon plasma.

In this helium-3 experiment, the helium-3 ion (containing 2 protons and 1 neutron) collided with a gold ion. The PHENIX detector picked up a triangular pattern emerge from the collision, each point of the triangle representing 3 tiny hotspots, each one believed to be the scrambled remains of the helium-3′s 2 protons and 1 neutron. And these hotspots behaved just as a quark-gluon should — like a perfect liquid.

Read more at Discovery News

The Curious Case of the Elusive, Slimy Nautilus


Watch this video on The Scene.

Aside from losing a $20,000 camera, by most measures July’s hunt for the ultra-rare crusty nautilus was a rousing success. The camera was stuck 1,000 feet deep when Rick Hamilton at last pulled up Allonautilus scrobiculatus in a cage off the coast of Manus Island in Papua New Guinea. And so he grabbed his GoPro and leaped into the water, capturing the first-ever video of a live crusty nautilus, a creature that human eyes haven’t glimpsed since 1984. It was a beauty, and it was…really slimy. And not to tell nautiluses their business, but they aren’t supposed to be really slimy.

You’re probably familiar with the nautilus. It’s that cephalopod (a group that includes the squids and cuttlefish and octopuses) with a beautiful tiger-striped shell that scoots around Earth’s oceans and occasionally runs into things. But this slimy, fuzzy nautilus, it’s more mysterious—far more mysterious. That’s changing thanks to the work of Hamilton, who directs the Nature Conservancy’s Melanesia Program, and other scientists. Not to mention that $20,000 camera, which put in a solid effort. May it rest in peace. (“We still know where it is,” says Hamilton. “I just can’t get it unstuck. I was thinking about selling it on eBay with a ‘pick up as is, where is’ clause.”)

Throughout history, humans have coveted the gorgeous shell of the nautilus—which tends to float around and wash ashore, as many as 11 years after its owner died—for all manner of uses. People turn them into things like jewelry or use them as chalices, which is pretty damn baller. The shell is impressive on the outside, but even more impressive internally. It’s divided into chambers, which progressively shrink as the structure spirals toward the center. By pumping water in and out of these chambers, the animal can control its buoyancy.

The incredible nautilus shell. The actual animal lives only in that big chamber, pumping water in and out of the smaller ones to control its buoyancy. It’s like having an arm floaty–that humans sometimes use as a cup.
So, the crusty nautilus’ hairy, yellow slime. It’s a sort of protein-dense skin called a periostracum, something you’ll also find on bivalves and oceanic snails. “It feels like wet moss,” says Hamilton. “If you push on the nautilus it’ll actually come off, it’ll flake off.” (The creature is informally known as the crusty nautilus because it’s encrusted with this layer of slime, not because it’s brittle or irritable or anything.)

The skin is an adaptation, Hamilton figures, to help the crusty nautilus avoid a trip to the stomach of a predator. This is, after all, a sluggish creature, relying on its armor to survive, as opposed to its cousin the cuttlefish, which instead deploys astounding camouflage. Of particular concern for the crusty is its other cousin the octopus. “They’ll attach onto the shell and drill a hole into them,” says Hamilton, “and then inject a poison that kills them, then pull the meat out. And we think that perhaps the crusty skin makes it a bit slippery. It’s a bit harder for the octopus to attach to the shell.”

You might ask yourself, then, why only the crusty nautilus would get all slimy while another nautilus it shares a habitat with, Nautilus pompilius, does not. And the answer may come down to lifestyle choices. Nautiluses are largely scavengers, feeding on things like fish that have perished and sunk to the ocean bottom, and typically they hang out in the dark depths, wandering great distances along the seafloor.

The crusty nautilus looks a bit like a tennis ball…that was left in the sun…and then grew tentacles and eyes.
But the crusty nautilus is different. Hamilton and his colleagues pulled up a total of eight crusties, successfully tagging one of them as well as one pompilius. Then they tracked their movements. They found that while pompilius tends to migrate horizontally along the seafloor, the crusty nautilus is going about things more vertically. During the day the crusty hangs out in the relative safety of the darker depths, but at night it ventures up the water column, scavenging on reef faces as it ascends. Here it finds an abundance of food—after all, a reef is far more biodiverse than the deep seafloor.

Now, nautiluses, like Batman, rely on darkness for protection. But the crusty nautilus’ roving lifestyle likely exposes it to more predators in the moonlit shallows. Thus would it do well to have a slippery shell as an extra precaution. The creature’s migration may also explain why “compared to the other nautiluses, it’s a bit like the tank of the battlefield,” says Hamilton. “It’s a solider animal.” Being a little beefier would bestow it yet another advantage as predators lurk about.

Both species of nautilus hugging it out.
Where the six species of nautilus can all agree, though, is how sweet it is that they live for so long—like, maybe as long as 100 years. That’s particularly weird because, in general, nature says the bigger you are, the longer you live. A blue whale will live far longer than a fruit fly, for instance. For its size, the nautilus shouldn’t be living anywhere near a century. And why that is isn’t yet clear. Even stranger, other cephalopods like squid and octopuses tend to be short-lived—maybe just a year or two.

That’s not all that separates the nautiluses from the rest of the cephalopod pack. Cephalopods showed up some 550 million years ago—way, way early in the history of complex animal life. Back then, the tentacled beings all had shells, but as the millennia wore on, they diversified and lost their armor, instead opting for camouflage and speed.

The nautilus, though, couldn’t be bothered with such change. It first showed up an incredible 500 million years ago and has held onto that shell all along. And considering the nautilus’ epic time on Earth, the crusty variety showed up really recently, perhaps as few as a million years ago. That’s nothing as far as evolutionary time is concerned. You’re looking at a species in its infancy, one science is just beginning to understand.

Read more at Wired Science

Sep 3, 2015

Fluffiest-Tailed Animal, 'Vampire Squirrel,' Captured in Video

The first known video of the mysterious “vampire squirrel” was recently acquired by scientists working in Indonesia, according to a new Science report.

The elusive squirrel, Rheithrosciurus macrotis, is famous both for the vampire-inspired legends surrounding it and for its tail, which last year was hailed as being the fluffiest among all mammals.

Andrew Marshall, a conservation biologist at the University of Michigan, and his colleagues set up 35 motion-triggered video cameras throughout Gunung Palung National Park in the Indonesian province of West Kalimantan. The vampire squirrel, also known as the Bornean tufted ground squirrel, is known to live in the park.

“I was sitting at the bar in Jakarta waiting to come home, looking through the pictures, and this (the video) popped up,” Marshall told Science reporter Erik Stokstad.

The video, shot in infrared and not in color because of low light conditions, shows the squirrel foraging through leaves for coveted nuts of the canarium tree. The nuts are so hard that the scientists have no idea how the little, fluffy-tailed squirrel manages to gnaw through them.

The squirrel’s pointy, bat-like ears and mysterious ways probably led to the vampire-like legends surrounding it. Local folklore holds that the 14-inch-long squirrel attacks forest deer and drinks their blood. That has never been substantiated.

Read more at Discovery News

Rare 1,800-Year-Old Sarcophagus Recovered in Israel

Israeli authorities have recovered an impressive Roman-era sarcophagus that construction workers tried to conceal after stumbling upon it at a building site, Israel’s Antiquities Authority (IAA) announced on Thursday.

The 1,800-year-old stone coffin, which the IAA describes as one of the most important and beautiful ever discovered in the country, is sculpted on all sides, weighs two tons and is 2.5 meters (8 feet) long. A life-sized figure of a person is carved on the lid.

The sarcophagus was recovered in the southern coastal city of Ashkelon during an overnight operation between Tuesday and Wednesday. IAA inspectors noticed the finely decorated coffin was severely damaged when building contractors improperly removed it from the ground.

“They decided to hide it, pulled it out of the ground with a tractor while aggressively damaging it,” the IAA wrote in a statement.

The sarcophagus was then hidden beneath a stack of sheet metal and boards.

“The contractors poured a concrete floor in the lot so as to conceal any evidence of the existence of the antiquities site,” the IAA said.

According to Amir Ganor, head of the Inspection Department at the Israel Antiquities Authority, building permission was given on condition that any discovery of antiquities in the area would be reported.

"In this case, the building contractors chose to hide the rare artifact and their action has caused painful damage to history. Legal proceedings will now be taken against those involved, thereby leading to a delay in construction and related expenditures," Ganor said in a statement.

According to archaeologist Gaby Mazor, the sarcophagus was likely made for a wealthy Roman family.

“Such sarcophagi were usually placed in or next to a family mausoleum. The high level of decoration attested to the family’s affluence, which judging by the depicted motifs was probably not Jewish,” Mazor said.

The lid of the sarcophagus is adorned with the carved image of a man, possibly representing the deceased, leaning on his left arm.

“He is wearing a short-sleeved shirt decorated with embroidery on the front. A tunic is wrapped around his waist. The figure’s eyes were apparently inlaid with precious stones that have disappeared and the hair is arranged in curls, in a typical Roman hairstyle,” Mazor said.

Read more at Discovery News

As Sixth Largest Salt Lake Dries Up, Iran Tries to Save It

The sixth largest salt lake in the world is drying up and Iran is trying to save it with what will be that country’s most expensive environmental project ever.

Iran president Hassan Rouhani’s government plans to spend about $6 billion over the next decade to try and revive Lake Urmia in northwestern Iran. The lake, which was once a haven for an array of wildlife, has now shriveled to just 10 percent of its previous maximum size.

Iran’s $660 million plan includes funds for 88 projects, most of which target improved irrigation systems and other infrastructure.

Hossein Akhani, a botanist at the University of Tehran, told Discovery News that the 2008-square-mile lake was in “good condition” until 1995. Akhani first visited the lake in 1987 when it “was full of water and the coasts were full of salt-tolerant plants.”

“The lake was a paradise for flamingos and a habitat for large numbers of water fowls and migratory birds,” Akhani said. “The water included the endemic brine shrimp, which feed on phytoplankton and were the main food for the birds. Furthermore, it included 102 islands, some of which were large enough to be inhabited by mammals, such as Persian fallow deer and wild sheep.”

Since the lake began to dry up about two decades ago, both humans and wildlife have been impacted.

Many of its animals sunk into the mud and died. Others escaped to the mainland, where they have been hunted. Without water, the brine shrimp have died out, Akhani said, “so there is no more food for the birds.” Native rare plants, such as the salt-tolerant plants that Akhani studies, are disappearing too.

As for people in the region, they are now being exposed to “noxious dust” coming off the lakebed, and local crops are threatened, Richard Stone, who prepared a report about the project to save the lake in this week’s issue of Science, told Discovery News.

At least four factors could have adversely affected the lake, according to Stone: drought and rising temperatures, poor water management, damning of three rivers that supply nearly 90 percent of Lake Urmia’s water, and a switch by local farmers to “thirstier crops.”

Stone explained that the damning of the rivers was done for irrigation and hydropower. In terms of crops, the region used to be known for its winemaking before 1979. After the country became an Islamic republic, and wine was forbidden, farmers turned to more water-reliant crops, such as sunflowers, wheat, apples and sugar beets.

Akhani is a member of the Ecological Restoration Working Group that has submitted a detailed plan to authorities based on ecological and International Union for Conservation of Nature criteria.

Akhani and his colleagues hope that members of the international scientific community and governments from other countries will, he said, “work with the Iranian authorities and scientists to monitor and support the restoration of the lake, and avoid mistakes that in former times caused the desiccation of the lake.”

Read more at Discovery News

Alien Oceans' Glint Could Reveal Habitable Worlds

The bright glint of alien oceans may be visible from afar, allowing astronomers to flag potentially habitable exoplanets.

As Earth travels around the sun, it moves through phases much like the moon when seen from afar. The planet’s oceans reflect a great deal of light, especially during the crescent phase. The same principle should apply to exoplanets, researchers say.

“Seeing excessive brightness at the crescent phases could be a telltale signal of ocean planets,” Tyler Robinson, of NASA’s Ames Research Center in Moffett Field, California, said at the Astrobiology Science Conference in Chicago in June.

Although a host of satellites monitor Earth, few eye the planet as a whole. As a result, many exoplanet scientists turn to models to understand how Earth might appear if it were a distant alien world. However, the accuracy of these models can be difficult to gauge without observations to verify them.

Scientists have made a few attempts to address this issue. In 1993, for example, Carl Sagan and other researchers used observations made by NASA’s Jupiter-studying Galileo spacecraft during a 1990 flyby of Earth to search for signs of life on our planet.

And in 2009, NASA’s Lunar Crater Observation and Sensing Satellite(LCROSS) moon mission observed Earth at several phases, including near-full and crescent, in order to calibrate its instruments. Robinson and his colleagues analyzed these data, and found that the near-infrared and ultraviolet/visible light observations provided an approximation of how Earth might appear through extreme phases across various spectrums. Their study was published in 2014 in The Astrophysical Journal.

“LCROSS looked at Earth for calibration, but its measurements were good for science,” Robinson said.

The results showed that, although less of Earth’s surface was visible during its crescent phase, the brightness of the planet increased due to the light reflecting off its oceans. In visible light, the glint increased the planet’s brightness by as much as 40 percent; in the near-infrared, Earth shone nearly 80 percent more brightly, Robinson said.

Robinson was also a co-author on a different paper that examined similar, though less detailed, observations of Earth using NASA’s Deep Impact spacecraft (which performed up-close examinations of two different comets, in 2005 and 2010).

The observations performed by LCROSS — the first high-spectral-resolution observations of Earth in its crescent phases — lined up well with predictions based on existing models, Robinson said.

However, similar results gained from observations of an exoplanet would not automatically be signs of an ocean, he cautioned; clouds and ice could also affect the brightness of a planet. Follow-up studies of the exoplanet’s atmospherecould reveal more about the world’s potential habitability.

Read more at Discovery News

Sep 2, 2015

King Cobra, Python Tangle in Singapore Street Fight

Students on campus at Singapore's Nanyang Technological University got a firsthand look at what happens when big, dangerous snakes clash. This being the Internet era, they also documented it on video.

Channel News Asia reported on a half-hour battle between a king cobra and a python, just off the curb of a busy street on the university's grounds.

Students told Channel News Asia that the python seemed to have been winning, having gotten a constricting grip on the cobra's head. But, as shown about half-way through the video clip above, the cobra somehow wriggled free and headed off for a nearby wooded area.

University pest control staff members were able to bag the python unharmed, but the cobra initially evaded capture. Hours later, though, the cobra was lured out of a storm drain and also captured in a bag.

Read more at Discovery News

Animal Without Organs Digests Food on Its Body

Eating without having internal organs would seem to pose incredible challenges, but the marine animal Trichoplax has solved this challenge by digesting meals on top of its body, a new study finds.

The discovery, reported in the journal PLOS ONE, demonstrates that lack of neurons, muscles and bodily organs does not necessarily mean a creature is lacking in complex behaviors.

"Despite having only six cell types and lacking synapses, Trichoplax coordinates a complex sequence of behaviors culminating in external digestion of algae," lead author Carolyn Smith of the National Institutes of Health, and her colleagues Natalia Pivovarova and Thomas Reese wrote.

German zoologist Franz Eilhard Schulze first discovered Trichoplax in 1883. He noticed it moving along the walls of a seawater aquarium at the Zoological Institute in Graz, Austria. He described the small creature as resembling a hairy plate.

Since then, the species has been found all over the place: in the Red Sea, the Mediterranean, the Caribbean, off Hawaii, Guam, Samoa, Japan, Vietnam, Brazil, and Papua New Guinea, and on the Great Barrier Reef off the east coast of Australia, just to name a few locations.

It's since been determined that Trichoplax, defined as a marine metazoan, has just six cell types. Humans, in contrast, have about 200.

Using high tech electron microscopy and cell imaging, Smith and her team observed Trichoplax and its behaviors. They noted that the creature has cilia, which are minute, hair-like structures that line certain cells and beat in rhythmic waves. This helps the disk-resembling animal move.

Food, however, stops it in its tracks.

"When Trichoplax glides over a patch of algae," the researchers explained, "its cilia stop beating so it ceases moving."

A subset of one of the animal's cell types, lipophils, then secretes granules that break down the algae.

Read more at Discovery News

New Species of Ancient 'River' Dolphin Lived in the Ocean

The fossilized remains of a new species of ancient river dolphin that lived at least 5.8 million years ago have been found in Panama, and the discovery could shed light on the evolutionary history of these freshwater mammals.

Researchers found half a skull, a lower jaw with an almost complete set of conical teeth, a right shoulder blade and two small bones from a flipper. The fossils are estimated to be between 5.8 million and 6.1 million years old, making them from the late Miocene epoch, researchers said in a new study.

The ancient river dolphin, named Isthminia panamensis, was calculated to be more than 9 feet (2.7 meters) long, according to the study.

The ancient mammal was discovered on the Caribbean coast of Panama, at the same site where other marine animal fossils have been found, which suggests that I. panamensiswas also a saltwater species, the researchers said.

I. panamensis is the only fossil of a river dolphin known from the Caribbean, the researchers said in the study.

"We discovered this new fossil in marine rocks, and many of the features of its skull and jaws point to it having been a marine inhabitant, like modern oceanic dolphins," study lead author Nicholas Pyenson, a curator of fossil marine mammals at the Smithsonian's National Museum of Natural History in Washington, D.C., said in a statement.

But despite dwelling in the salty waters of the Caribbean Sea, I. panamensis is actually more closely related to modern-day freshwater river dolphins, the researchers said. In fact, "Isthminia is actually the closest relative of the living Amazon river dolphin," study co-author Aaron O'Dea, a staff scientist at the Smithsonian Tropical Research Institute in Panama, said in a statement.

Only four species of river dolphins exist today (although one, the Yangtze river dolphin, is now likely extinct), all living in freshwater or coastal ecosystems. All of these river dolphins moved from marine to freshwater habitats, developing broad, paddlelike flippers; flexible necks; and heads with particularly long, narrow snouts as they evolved, according to the study. These adaptations allowed the river dolphins to better navigate and hunt in winding, silty rivers, the researchers said.

"Many other iconic freshwater species in the Amazon — such as manatees, turtles and stingrays — have marine ancestors, but until now, the fossil record of river dolphins in this basin has not revealed much about their marine ancestry," Pyenson said. "[I. panamensis] now gives us a clear boundary in geologic time for understanding when this lineage invaded Amazonia."

Read more at Discovery News

Green Slime in Antarctica Offers Window into the Past

A thin layer of bright green slime at the bottom of an Antarctic lake is giving scientists a glimpse at life on Earth 2.4 billion years ago, according to new research from the University of California, Davis.

The bacteria found in the slime produces a millimeter-thick layer of concentrated oxygen at deep depths that are otherwise devoid of oxygen, or anoxic. These so-called “oxygen oases” reflect a time before photosynthesis was widespread, when oxygen was not yet abundant in Earth’s atmosphere.

Instead, the element was found mainly in small, localized pockets that were produced by a select few organisms — similar to the handful of microbes can survive in harsh Antarctic lakes.

“The thought is, that the lakes and rivers were anoxic, but there was light available, and little bits of oxygen could accumulate in the mats,” UC-Davis professor Dawn Sumner explains in a news release.

That all changed approximately 2.5 billion years ago, however, when evolving bacteria began to photosynthesize. The newly capable organisms introduced oxygen throughout the planet, an event that has since been dubbed the Great Oxidation Event.

The rest, of course, is history!

From Discovery News

Fly With New Horizons During Stunning Pluto Encounter

NASA’s New Horizons spacecraft made history when it zipped past Pluto and its system of moons during a hair-raising encounter on July 14, coming within 7,800 miles of the dwarf planet’s surface.

Now, the mission team has stitched together the observations made by the probe during its historic flyby, creating a stunning high-resolution view of what it looks like to barrel through the Kuiper Belt at 31,000 miles per hour:

Captured in the video is the long approach to Pluto and its moons, the wonderful high-resolution global view of Pluto during closest approach, and then the ring of scattered sunlight as Pluto blocks the sun from view as a stunning eclipse.

As discussed by research scientist Stuart Robbins, at the Southwest Research Institute in Boulder, Colo., who created this flyby video, to make the animation more cinematically appealing, he had to tweak the timescale between frames.

“The final product goes from one second of movie time equaling 30 hours at the beginning and end, to one second of movie time equaling 30 minutes for the closest-approach section,” writes Robbins in a blog post. The approach to Pluto occurred over a long period, whereas the point of close approach was gone in a flash, so Robbins basically hit the slow-mo button when New Horizons buzzed the dwarf plant’s surface, but sped up the footage when the spacecraft was far away.

Read more at Discovery News

Sep 1, 2015

5-Foot-Long Spider Relative Found In Iowa

A human-sized prehistoric relative of spiders has just been discovered in northeastern Iowa, according to a new study.

The previously unknown species of sea scorpion, Pentecopterus decorahensis, was named after an ancient Greek warship, the penteconter, and is described in the latest issue of the journal BMC Evolutionary Biology.

“The new species is incredibly bizarre,” lead author James Lamsdell of Yale University said in a press release. “The shape of the paddle — the leg which it would use to swim — is unique, as is the shape of the head. It’s also big!”

Lamsdell and his colleagues excavated more than 150 fossil fragments from the ancient predator, which lived 460 million years ago, long before the first dinosaurs emerged. The site itself is noteworthy, as the fossils were entombed in thick shale located within an ancient meteorite impact crater that today is mostly submerged by the Upper Iowa River.

“Perhaps most surprising is the fantastic way it is preserved,” Lamsdell said. “The exoskeleton is compressed on the rock but can be peeled off and studied under a microscope. This shows an amazing amount of detail, such as the patterns of small hairs on the legs. At times it seems like you are studying the shed skin of a modern animal — an incredibly exciting opportunity for any paleontologist.”

He and his colleagues believe that Pentecopterus was a eurypterid (sea scorpion), which refers to a group of extinct animals related to today’s spiders, scorpions, mites and ticks. This particular species is the world’s oldest known sea scorpion.

Although the animal lived so long ago, its remains provide clues on how it lived. The structure of its rear limb paddles suggests that it used them for either swimming or digging. Since its second and third pairs of limbs seem to have angled forward, the scientists suspect that they were involved primarily in prey capture.

Its three rearmost pairs of limbs are shorter than its front pairs. This indicates that it might have walked on six legs instead of eight. The rear limbs were also covered in setae (stiff bristles), similar to what covers some modern crabs. They probably expanded the surface area of the paddles during swimming, and could have also helped the sea scorpion to feel its way around, similar to whiskers on a cat.

Huaibao Liu of the Iowa Geological Survey and the University of Iowa led the fossil dig and is a co-author of the paper.

Read more at Discovery News

Titanic's Last Lunch Menu Up for Auction

Before the RMS Titanic plunged into the icy waters of the North Atlantic, passengers aboard the storied passenger ship may have feasted on corned beef, potted shrimp and dumplings, according to an unusual artifact from the doomed ship — a lunch menu dated April 14, 1912, the day before the tragic sinking.

The menu, along with several other items from the Titanic’s final days afloat, will be put up for auction Sept. 30 in New York City. The crumpled menu is expected to sell for at least $50,000, according to Lion Heart Autographs, the online auction house handling the sale.

First-class passenger Abraham Lincoln Salomon salvaged the creased and tattered carte du jour, which was tucked inside his pocket when the ship went down on April 15, 1912. Salomon was one of just 12 people who dodged death by boarding the infamous Lifeboat No. 1 or “Money Boat” (although, in total, about 700 of the ship’s 2,223 passengers and crewmembers survived).

The large lifeboat, which could have held 40 people, was nicknamed for the five wealthy passengers it carried to safety, as well as for the widely held belief that those passengers paid the only other people onboard the boat — seven Titanic crewmembers — to row away from the sinking ship instead of taking on any more survivors.

In addition to the battered menu, Salomon saved a small ticket from the Titanic’s Turkish baths weighing chair, a custom chair that recorded a sitter’s weight. Inscribed on the ticket are the names of three of the passengers who accompanied Salomon on the lifeboat — Miss Laura Mabel Francatelli, Sir Cosmo Duff-Gordon and Lady Lucy Duff-Gordon. The tiny ticket is expected to fetch as much as $10,000 at auction.

The final “Money Boat” artifact to be auctioned off is a letter sent by Francatelli, who was an employee of fashion designer Lady Duff-Gordon, to Salomon, dated six months after the Titanic’s sinking. The letter reads:

“We do hope you have now quite recovered from the terrible experience. I am afraid our nerves are still bad, as we had such trouble & anxiety added to our already awful experience by the very unjust inquiry when we arrived in London.”

Written on stationary from the upscale Plaza Hotel in New York City, the letter could sell for upward of $4,000, according to Lion Heart Autographs.

In addition to the unusual Titanic memorabilia, the auction will feature a number of other interesting items related to important events in history.

For example, a stack of 170 letters written by Aldrich Ames — the former CIA operative convicted in 1994 for serving as a double agent for the Soviet Union — tells an interesting tale of the inner workings of the CIA, as well as life imprisonment. There is also a letter written by Albert Einstein in April 1938 that was sent to a man named John Stone of St. Petersburg, Florida, in which the Nobel Prize-winning physicist advises Stone against a career in mathematics.

Read more at Discovery News

Fragments of World's Oldest Koran May Predate Muhammad

British scholars have suggested that fragments of the world's oldest known Koran, which were discovered last month, may predate the accepted founding date of Islam by the Muslim prophet Muhammad.

The Times of London reported that radiocarbon dating carried out by experts at the University of Oxford says the fragments were produced between the years 568 A.D. and 645 A.D. Muhammad is generally believed to have lived between 570 A.D. and 632 A.D. The man known to Muslims as The Prophet is thought to have founded Islam sometime after 610 A.D., with the first Muslim community established at Medina, in present-day Saudi Arabia, in 622 A.D.

"This gives more ground to what have been peripheral views of the Koran's genesis, like that Muhammad and his early followers used a text that was already in existence and shaped it to fit their own political and theological agenda, rather than Muhammad receiving a revelation from heaven," Keith Small of Oxford's Bodleian Library told the Times.

The two sheets of Islam's holy book were discovered in a library at the University of Birmingham in England, where they had been mistakenly bound in a Koran dating to the seventh century. They were part of a collection of 3,000 Middle Eastern texts gathered in Iraq in the 1920s.

Muslims scholars have disputed the idea that the Birmingham Koran predates Muhammad, with Mustafa Shah of the University of London's School of Oriental and African Studies telling the Times: "If anything, the manuscript has consolidated traditional accounts of the Koran's origins."

The first known formal text of the Koran was not assembled until 653 A.D. on the orders of Uthman, the third caliph, or leader of the Muslim community after Muhammad's death. Before that, however, fragments of the work had circulated through oral tradition, though parts of the work had also been written down on stones, leaves, parchment and bones. The fragments of the Birmingham Koran were written on either sheepskin or goatskin.

Read more at Discovery News

Mysterious 2,000-Year-Old Podium Found in Jerusalem

A mysterious pyramid-shaped flight of stairs dating to the time of Jesus, has been unearthed in ancient Jerusalem, the Israel Antiquities Authority (IAA) announced.

Made from large ashlar — or finely cut — stones, the 2,000-year-old stepped structure leads to a podium.

The puzzling staircase was found alongside a stepped street that once led Jewish pilgrims from the rock cut Pool of Siloama on the southern slope of the City of David to the Second Temple which stood atop the Temple Mount.

Consisting of enormous stone slabs, the street was built sometime in the fourth decade of the 1st century A.D. and was one of the largest construction projects undertaken in Jerusalem during the Second Temple period.

The Second temple era, running from 538 B.C. to 70 A.D., refers to the lifetime of the temple built by King Herod the Great to replace the First Temple, razed by the Babylonians around 587 B.C.

In 70 A.D., the Second Temple also vanished as the Romans sacked the city and plundered Herod’s magnificent white and gold temple. Then they paraded the treasure, which also helped finance the building of the Colosseum, through the streets of Rome in triumph.

Archaeologists do not know yet what the pyramid-shaped staircase was used for. Rabbinic texts refer to stone platforms used for auctions or as “Stone of Claims” to find lost belongings, but nothing like that structure has been found in Jerusalem or elsewhere in ancient Israel.

“Given the lack of a clear archaeological parallel to the stepped-structure, the purpose of the staircase remains a mystery,” archaeologists Nahshon Szanton and Joe Uziel said in a statement.

Read more at Discovery News

Yearlong Mock Mars Mission to Test Mental Toll of Isolation

On Friday (Aug. 28), six scientists left the comforts of civilization, set to be gone for an entire year. Their mission will simulate what it might be like for astronauts journeying to Mars.

In the confines of a 36-foot-wide (11 meters) and 20-foot-high (6 m) solar-powered dome in a remote location on the island of Hawaii, the six team members will have to live together for 365 days. They will have no face-to-face contact with humans outside of the dome. This is the fourth and longest such mission carried out by the Space Exploration Analog and Simulation (HI-SEAS) program, and its goal is to find out how people will respond to the isolation that might accompany a mission to Mars.

“We hope that this upcoming mission will build on our current understanding of the social and psychological factors involved in long-duration space exploration,” Kim Binsted, principal investigator for HI-SEAS, said in a statement from the University of Hawaii.

The HI-SEAS project, which is based at University of Hawaii at Manoa, has put crews into the isolated mock Mars colony in four previous missions: two 4-month missions in 2013 and 2014, respectively, and an eight-month mission that ended in June 2015. During those previous trips, the crewmembers were allowed to leave the dome in spacesuits, occasionally engaging in outdoor activities like golfing, but mostly to do research in the local environment, the way members of a real Mars crew would.
MD2: settled into quarters. #domelife #hiseas #montana pic.twitter.com/MUWJJTTl9a — Carmel Johnston (@_CarmelJohnston) August 31, 2015

The team has a yearlong supply of food and water. The cuisine, which the team must be able to store for months at a time, is similar to what astronauts eat. Team member Sheyna Gifford tweeted on Saturday (Aug. 29) a picture of a quesadilla, with some peas and corn. She wrote, “First dinner in simulated space: The cheese & turkey quesadilla & all the veggies were all dehydrated 30 min. ago.”

The HI-SEAS habitat features a downstairs area with a lab, a kitchen, a common workspace, an exercise area, a dining room and a bathroom. Upstairs are six small bedrooms and a bathroom.

The current mission will “focus on crewmember cohesion and performance,” the statement said. “HI-SEAS researchers are working to develop effective team composition and support strategies to allow crews to successfully travel to Mars and back, an estimated three-year journey.”

Researchers will monitor the six crewmembers throughout the mission via cameras, body-movement trackers and other methods. Back in the real world, the researchers will gather data on “a wide range of cognitive, social and emotional factors that may impact team performance,” according to the statement.

Read more at Discovery News

Aug 31, 2015

Human Eye's Blind Spot Can Shrink with Training

The blind spot of the human eye can be shrunk with certain eye-training exercises, thus improving a person’s vision slightly, a small new study suggests.

In the study of 10 people, researchers found that the blind spot — the tiny region of a person’s visual field that matches up with the area in the eye that has no receptors for light, and hence cannot detect any image — can shrink 10 percent, with special training.

That amount of change “is quite an improvement, but people wouldn’t notice, as we are typically unaware of our blind spots,” said study author Paul Miller, of the University of Queensland in Australia. Normally, the brain pulls in visual information from the regions surrounding the blind spot, compensating for it, so people don’t usually perceive it.

“The real significance is that our data shows that regions of blindness can be shrunk by training, and this may benefit people who suffer from pathological blindness,” Miller told Live Science.

The blind spot of the eye exists because there are no light receptors in a small region of the retina. In this spot, the optic nerve, which extends toward the eye from deep within the brain, reaches the back of the eye, at the retina’s surface. The nerve prevents the light receptors that line the rest of the retina from being in that spot.

In the study, the researchers trained 10 people for 20 days on what researchers call a “direction-discrimination” task. During the task, the investigators used an image of a ring, centered in the blind spot of one of the person’s eyes. Waves of dark and light bands moved through the ring, and the participants were asked what direction the waves were moving. In another task, they were asked what color the ring was.

But the size of the ring was manipulated — sometimes, it was made small enough that it fell completely within a person’s blind spot, while other times, it was larger, falling within the person’s field of vision. When the training began, the exercises were designed so that the people in the study were able to correctly judge the direction of the wave’s movement only about 70 percent of the time.

Eventually, the people’s eyes were better able to detect the image in their blind spot. At the end of the study, the participants’ ability to correctly judge both the direction of the waves and the color of the ring improved.

It does not seem that the improvement was simply due to practicing the task, because the results of doing the training with one eye did not result in any shrinking of the blind spot in the other eye, the researchers said.

Instead, the results suggest that the training increased the sensitivity of certain receptors that overlap or are adjacent to the blind spot, they said. The eye therefore becomes more sensitive to the weak signals that come from near or within the site of blindness.

Read more at Discovery News

Nazi 'Gold Train' Existence in Poland in Doubt Again

A regional governor in Poland said Monday he had serious doubts about the alleged discovery of a Nazi gold train days after a deputy culture minister revealed he was “more than 99 percent sure” one had been found.

“There is no more proof for this alleged discovery than for other claims made over the years,” Tomasz Smolarz, governor of the southwestern region of Lower Silesia, told reporters.

Two anonymous fortune hunters claim they have pinpointed the Nazi-era loot.

“It’s impossible to claim that such a find actually exists at the location indicated based on the documents that have been submitted,” Smolarz said, adding that he had set up a special unit including historians and geologists to scrutinise the alleged discovery.

Global media have for days been abuzz with talk of trains full of jewels and gold stolen by the Nazis after the two men — a German and a Pole — claimed to have found an armoured train car buried near the city of Walbrzych.

On Friday, Polish Deputy Culture Minister Piotr Zuchowski said he had seen a convincing ground-penetrating radar image of the alleged Nazi train.

“I’m more than 99 percent sure such a train exists, but the nature of its contents is unverifiable at the moment,” Zuchowski told reporters, adding that he could make out platforms and cannons on the photo.

Smolarz said Monday he had not seen any such image.

“The fact that this train is armoured suggests there could be valuable objects inside” including artworks, archival documents or treasures, Zuchowski added.

The World Jewish Congress has asked that any valuables found that once belonging to victims of the Holocaust should be returned to their owners or heirs.

Zuchowski said someone who had been involved in hiding the train, which is over 100 metres (330 feet) in length, had disclosed its location before dying.

Read more at Discovery News

330-Pound Beavers: What Earth Would Be Like Without Us

If humans never existed, lions, saber–tooth tigers, 330–pound beavers and house-sized armadillos would be walking around Texas right now. A new study from researchers at Aarhus University demonstrates what the world would look like for mammals if the most destructive super predator of them all — Homo sapiens — had never been around.

The study was born out of the team’s previous research, which found that a lot of mammal species that went extinct during the last Ice Age was mostly due to the spread of humans rather than climate change.

“Last year we published another study, which along other studies, clearly suggested that humans were a massive driver in the large extinction which occurred near the end of the last ice age,” lead study author and postdoctoral fellow in bioscience Soren Faurby told Foxnews.com.

“During this work we started talking about just how big the effects of humans was and how the world would have been different if humans had not influenced the distribution of any species within the last 130,000 years and I started estimating this by generating attempts of so–called present-natural distributions of all mammalian species, meaning where they potentially could have been today.”

According to the study, rhinos and elephants would thrive alongside bears and Eurasian elk in Europe, while American lions and camels (among other things) would be prowling around North America.

“Texas and Mexico would likely naturally have some of the highest diversity,” Faurby suggested. “Among the extinct North American species [that would be alive today] are short–faced bears, American lions, saber–tooth cats, Dire wolfs, giant ground sloths, mastodons, mammoths, camels, giant beavers (330 pounds or so), tapirs, and glyptodonts (house sizes armadillo relatives).”

Along with mapping out the current patterns of mammal diversity, the researchers had to use historic sources to determine how some species were distributed — for instance, what the Europeans saw when they first came to North America. However, for species that went extinct when the last Ice Age ended this wasn’t possible due to both the limited data available and the climate today being so different that the species wouldn’t be in the same location geographically.

“For these species we instead estimated the potential range based on the current ranges of the species used to co-occur with,” Faurby told Foxnews.com. “The extinct elephant (Straight tusked elephant, Elephas antiquus) and extinct rhinos (two species of Stephanorhinus) used to co–occur with species currently widely distributed in Northern Europe and it is therefore likely that this elephant and rhino would be found in the same overall places without human involvement.”

Today, sub–Saharan Africa has the greatest diversity of big mammal species and is in many ways the last refuge for them, with the Serengeti being one of the last places on Earth to see such a large diversity.

Read more at Discovery News

Earth Has More Than 1,500 Yet-Undiscovered Minerals

If you thought your rock and mineral collection was reasonably complete, guess again.

A team of researchers, led by the Carnegie Institute for Science’s Robert M. Hazen, used a sophisticated statistical modeling system to calculate that the Earth has a lot of undiscovered minerals — 1,563, to be precise — to add to the nearly 5,000 that already are known. Moreover, the scientists predict that Earth’s mineral diversity is unique, and is not duplicated anywhere else in the universe — even on Earth-like rocky exoplanets.

Those findings are contained in an quartet of recently published articles in Canadian Mineralogist, Mathematical Geoscience, American Mineralogist, and Earth and Planetary Science Letters.

Minerals are naturally occurring, inorganic substances that are crystalline — that is, have an ordered arrangement of atoms — and definite chemical compositions. They can be formed with the help of a variety of different types of geological activity, ranging from volcanoes and plate tectonics to water-rock interactions, as well as by biologically-based chemical reactions.

The latter are particularly important, according to Hazen, who has long theorized the Earth’s diversity of minerals is related primarily to the development of life on this planet. More than two thirds of known minerals can be linked directly or indirectly to biological activity, such as the carbonate minerals created by freshwater bacteria. The rise of bacterial photosynthesis 2.4 billion years ago, which dramatically increased the atmosphere’s oxygen concentration, also expanded the number of mineral species.

Hazen and his colleagues used statistical models of ecosystems and compared them to mineralogical databases in order to predict that thousands of mineral species that have been created during the Earth’s history. Some have been lost due to burial, erosion or subduction back into the Earth’s mantle, but by the team’s calculations, 1,563 of them still exist and are waiting to be discovered.

Another weird fact: Most of the earth’s mineral types are rare, and found at five or fewer locations on the planet.

From Discovery News

Ballet of Death for Stars in Cosmic Butterfly Photo

Two dying stars are in a dance of death in this spectacular image of the Twin Jet planetary nebula.

The butterfly shape is created by the stellar ballet of the two sun-like stars at the end of their lives.

The primary star of this binary system is now a red giant, between 1.0 and 1.4 times the mass of the sun. It’s blowing away its outer gaseous envelope to expose its stellar core and will eventually contract into a white dwarf.

The other star is already a white dwarf – a slowly cooling stellar corpse – between 0.6 and 1.0 times the mass of the sun.

The white dwarf is orbiting very close to the primary star and may even have been engulfed by the other’s expanding stellar atmosphere with the resulting interaction creating the nebula.

The pair orbit each other every 100 years, and astronomers think the gravity of one star is pulling ejected material from its binary companion and twisting it into two thin iridescent lobes which are stretching far out into space.

The lobes are still growing, and by measuring their rate of expansion, scientists have calculated that the nebula was created about 1200 years ago.

A planetary nebula is effectively a huge expanding shell of gas.

These growing shells are heated up, and the kaleidoscope of colors are caused by the different chemicals being ionized.

Within the lobes of Twin Jet planetary nebula PN M2-9 are two faint blue patches streaming horizontally outwards like veins, barely visible in the nebula’s rainbow colors.

These blue patches are actually violent twin jets moving at over a million kilometers per hour out from the rapidly rotating star system.

Over time, images of these jets show that they’re slowly changing their orientation, moving across the lobes, as they’re pulled by the wayward gravity of the binary system.

This rotation not only creates the lobes and jets, it also allows the white dwarf to strip gas from its larger companion, which then forms a large disc of material around the pair.

Read more at Discovery News

Aug 30, 2015

Chaos Tamed with New Math Definition

It’s that point when a smooth river turns into a tumultuous swirl of white water, the tornado that unpredictably changes course on a dime or the wild interactions of three planets under one another’s gravitational pull.

It’s chaos.

Although most people instinctively know chaos when they see it, there hasn’t been one, single, universally agreed-upon mathematical definition of the term. Now, scientists have tried to come up with a mathematical way to describe such chaotic systems.

The new definition, which was described in a paper published in July in the journal Chaos, could help identify seemingly smooth situations where the potential for chaos lurks, said study co-author Brian Hunt, a mathematician at the University of Maryland, College Park.

Chaos theory

Mathematician Henri PoincarĂ© first encountered the wild state while trying to describe the behavior of three celestial bodies under one other’s gravitational influence. Their movements proved difficult to predict beyond a few steps, and he termed this kind of erratic motion “chaos.”

Unlike truly random behavior, however, those systems were still “deterministic,” meaning that if one knew all the past laws and forces acting on the systems, one could perfectly predict where they would be in the future. By contrast, at the subatomic scale, particles are fundamentally uncertain, meaning there’s no way to perfectly predict what a given teensy particle will do.

But scientists didn’t really notice the chaos swirling in the universe until the 1960s, when computers had become powerful enough to crunch numbers and solve equations that couldn’t be worked out on paper, said Edward Ott, an applied physicist at the University of Maryland, College Park.

Sometimes, such as in the case of a simple pendulum, computers could predict behavior far into the future just by knowing a few facts. But other systems were much weirder. For instance, computers needed a ridiculous amount of extra information just to predict what a weather system would do just a few days into the future, which is why a four-hour weather forecast is typically spot-on but a 10-day forecast is little more than a historical guess. Go far enough into the future, “and, eventually, you won’t know anything about what the weather is going to do,” Ott told Live Science.

Once researchers realized that chaos was so often at play, mathematicians like Edward Lorenz began to develop newer theories for how these chaotic systems work. Yet decades later, no one had come up with a single, simple mathematical definition of chaos that seemed to perfectly capture all of these helter-skelter situations, Ott said.

Single rule for chaos


So Hunt and Ott tried to tackle the problem. The team developed a definition of chaos that was deceptively simple, and roughly based on the quantity similar to entropy, or the inherent tendency of things in the universe to move from a more orderly to a more disorderly state. They found that, if this entropylike number, called expansion entropy, is positive, the system could become chaotic, whereas one with zero expansion entropy would not become chaotic.

Read more at Discovery News

Black Holes Slug it Out in Quasar Deathmatch

In a galaxy, 600 million light-years away, a black hole deathmatch is ripping up spacetime, exposing some fascinating dynamics at the heart of a powerful quasar.

The quasar, which lives in the core of the galaxy Markarian 231 (Mrk 231), is the closest quasar to Earth and after studying years of data from the Hubble Space Telescope, a team of astronomers have realized that this particular quasar is driven by 2 black holes trapped in an orbital spiral of death.

This discovery could be critical to the study of quasars, the super-bright emissions blasting from galaxies in the distant universe. But the fact we have a quasar that’s comparatively close to our galactic neighborhood, Mrk 231 is a great laboratory to gain an insight to these enigmatic objects.

When studying the ultraviolet emissions blasting from the quasar’s accretion disk — a disk of superheated gases surrounding the central region — a deeply fascinating discovery was made. The quasar appears to be hollowed out, resembling a ring doughnut, and using dynamical models the researchers quickly realized that there must be two supermassive black holes, one more massive than the other, carving out the center.

As they orbit one another inside the quasar’s core, the smaller black hole carves out a region at the inner edge, also creating its own, smaller accretion disk. Calculations show that the pair complete one orbit every 1.2 years. The larger black hole is approximately 150 million times the mass of our sun and its smaller partner is 4 million times the mass of our sun.

“We are extremely excited about this finding because it not only shows the existence of a close binary black hole in Mrk 231, but also paves a new way to systematically search binary black holes via the nature of their ultraviolet light emission,” said Youjun Lu, of the National Astronomical Observatories of China, Chinese Academy of Sciences.

As the two black holes whip around one another, energy is lost through the emission of gravitational waves. And this means that they are slowly spiraling into one another, set to collide and merge in a few hundred thousand years.

The fact there are 2 supermassive black holes occupying the quasar speaks to Mrk 231′s violent past.

Known as a “starburst” galaxy, it is a powerhouse of star formation, birthing stars 100 times the rate of our Milky Way. The tidal disruption of a smaller galaxy merging with Mrk 231 is also highlighted by long tails of young, blue stars. The galaxy is also asymmetrical in shape, showing that the billions of stars are still in the process of settling. It’s likely that the smaller black hole in the galactic core was the central black hole occupying the smaller, merging galaxy.

“The structure of our universe, such as those giant galaxies and clusters of galaxies, grows by merging smaller systems into larger ones, and binary black holes are natural consequences of these mergers of galaxies,” added co-investigator Xinyu Dai of the University of Oklahoma.

Read more at Discovery News