Too Much Dark Matter in Galaxy Cluster? 'Dark Core' May Not Be So Dark After All

Astronomers were puzzled earlier this year when NASA's Hubble Space Telescope spotted an overabundance of dark matter in the heart of the merging galaxy cluster Abell 520. This observation was surprising because dark matter and galaxies should be anchored together, even during a collision between galaxy clusters.

Astronomers have abundant evidence that an as-yet-unidentified form of matter is responsible for 90 percent of the gravity within galaxies and clusters of galaxies. Because it is detected via its gravity and not its light, they call it "dark matter."

Now, a new observation of Abell 520 from another team of astronomers using a different Hubble camera finds that the core does not appear to be over-dense in dark matter after all. The study findings were published in The Astrophysical Journal.

"The earlier result presented a mystery. In our observations we didn't see anything surprising in the core," said study leader Douglas Clowe, an associate professor of physics and astronomy at Ohio University. "Our measurements are in complete agreement with how we would expect dark matter to behave."

Hubble observations announced earlier this year by astronomers using Hubble's Wide Field Planetary Camera 2 suggested that a clump of dark matter was left behind during a clash between massive galaxies clusters in Abell 520, located 2.4 billion light-years away. The dark matter collected into a "dark core" that contained far fewer galaxies than would be expected if the dark and luminous matter were closely connected, which is generally found to be the case.

Because dark matter is not visible, its presence and distribution is found indirectly through its gravitational effects. The gravity from both dark and luminous matter warps space, bending and distorting light from galaxies and clusters behind it like a giant magnifying glass. Astronomers can use this effect, called gravitational lensing, to infer the presence of dark matter in massive galaxy clusters. Both teams used this technique to map the dark matter in the merging cluster.

Clowe's team used Hubble's Advanced Camera for Surveys (ACS) to measure the amount of dark matter in the cluster. ACS observed the cluster in three colors, allowing the astronomers to distinguish foreground and background galaxies from the galaxies in the cluster. From this observation, the team made an extremely accurate map of the cluster's dark matter. "With the colors we got a more precise selection of galaxies," Clowe said.

The astronomers estimated the amount of dark matter in the cluster by measuring the amount of gravitational "shear" in the Hubble images. Shear is the warping and stretching of galaxies by the gravity of dark matter. More warping indicates the presence of more gravity than is inferred from the presence of luminous matter, therefore requiring the presence of dark matter to explain the observation. "The WFPC2 observation could have introduced anomalous shear and not a measure of the dark matter distribution," Clowe explained.

Using the new camera, Clowe's team measured less shear in the cluster's core than was previously found. In the study the ratio of dark matter to normal matter, in the form of stars and gas, is 2.5 to 1, which is what astronomers expected. The earlier WFPC2 observation, however, showed a 6-to-1 ratio of dark matter to normal matter, which challenged theories of how dark matter behaves.

"This result also shows that as you improve Hubble's capabilities with newer cameras, you can take a second look at an object," Clowe said.

His team is encouraging other scientists to study its data and conduct their own analysis on the cluster.

Read more at Science Daily

The Beginning of Everything: New Paradigm Shift for the Infant Universe

A new paradigm for understanding the earliest eras in the history of the universe has been developed by scientists at Penn State University. Using techniques from an area of modern physics called loop quantum cosmology, developed at Penn State, the scientists now have extended analyses that include quantum physics farther back in time than ever before -- all the way to the beginning. The new paradigm of loop quantum origins shows, for the first time, that the large-scale structures we now see in the universe evolved from fundamental fluctuations in the essential quantum nature of "space-time," which existed even at the very beginning of the universe over 14 billion years ago. The achievement also provides new opportunities for testing competing theories of modern cosmology against breakthrough observations expected from next-generation telescopes.

The research will be published on 11 December 2012 as an "Editor's Suggestion" paper in the scientific journal Physical Review Letters.

"We humans always have yearned to understand more about the origin and evolution of our universe," said Abhay Ashtekar, the senior author of the paper. "So it is an exciting time in our group right now, as we begin using our new paradigm to understand, in more detail, the dynamics that matter and geometry experienced during the earliest eras of the universe, including at the very beginning." Ashtekar is the Holder of the Eberly Family Chair in Physics at Penn State and the director of the university's Institute for Gravitation and the Cosmos. Coauthors of the paper, along with Ashtekar, are postdoctoral fellows Ivan Agullo and William Nelson.

The new paradigm provides a conceptual and mathematical framework for describing the exotic "quantum-mechanical geometry of space-time" in the very early universe. The paradigm shows that, during this early era, the universe was compressed to such unimaginable densities that its behavior was ruled not by the classical physics of Einstein's general theory of relativity, but by an even more fundamental theory that also incorporates the strange dynamics of quantum mechanics. The density of matter was huge then -- 1094 grams per cubic centimeter, as compared with the density of an atomic nucleus today, which is only 1014 grams.

In this bizarre quantum-mechanical environment -- where one can speak only of probabilities of events rather than certainties -- physical properties naturally would be vastly different from the way we experience them today. Among these differences, Ashtekar said, are the concept of "time," as well as the changing dynamics of various systems over time as they experience the fabric of quantum geometry itself.

No space observatories have been able to detect anything as long ago and far away as the very early eras of the universe described by the new paradigm. But a few observatories have come close. Cosmic background radiation has been detected in an era when the universe was only 380-thousand years old. By that time, after a period of rapid expansion called "inflation," the universe had burst out into a much-diluted version of its earlier super-compressed self. At the beginning of inflation, the density of the universe was a trillion times less than during its infancy, so quantum factors now are much less important in ruling the large-scale dynamics of matter and geometry.

Observations of the cosmic background radiation show that the universe had a predominantly uniform consistency after inflation, except for a light sprinkling of some regions that were more dense and others that were less dense. The standard inflationary paradigm for describing the early universe, which uses the classical-physics equations of Einstein, treats space-time as a smooth continuum. "The inflationary paradigm enjoys remarkable success in explaining the observed features of the cosmic background radiation. Yet this model is incomplete. It retains the idea that the universe burst forth from nothing in a Big Bang, which naturally results from the inability of the paradigm's general-relativity physics to describe extreme quantum-mechanical situations," Agullo said. "One needs a quantum theory of gravity, like loop quantum cosmology, to go beyond Einstein in order to capture the true physics near the origin of the universe."

Earlier work with loop quantum cosmology in Ashtekar's group had updated the concept of the Big Bang with the intriguing concept of a Big Bounce, which allows the possibility that our universe emerged not from nothing but from a super-compressed mass of matter that previously may have had a history of its own.

Even though the quantum-mechanical conditions at the beginning of the universe were vastly different from the classical-physics conditions after inflation, the new achievement by the Penn State physicists reveals a surprising connection between the two different paradigms that describe these eras. When scientists use the inflation paradigm together with Einstein's equations to model the evolution of the seed-like areas sprinkled throughout the cosmic background radiation, they find that the irregularities serve as seeds that evolve over time into the galaxy clusters and other large-scale structures that we see in the universe today. Amazingly, when the Penn State scientists used their new loop-quantum-origins paradigm with its quantum-cosmology equations, they found that fundamental fluctuations in the very nature of space at the moment of the Big Bounce evolve to become the seed-like structures seen in the cosmic microwave background.

"Our new work shows that the initial conditions at the very beginning of the universe naturally lead to the large-scale structure of the universe that we observe today," Ashtekar said. "In human terms, it is like taking a snapshot of a baby right at birth and then being able to project from it an accurate profile of how that person will be at age 100."

"This paper pushes back the genesis of the cosmic structure of our universe from the inflationary epoch all the way to the Big Bounce, covering some 11 orders of magnitude in the density of matter and the curvature of space-time," Nelson said. "We now have narrowed down the initial conditions that could exist at the Big Bounce, plus we find that the evolution of those initial conditions agrees with observations of the cosmic background radiation."

Read more at Science Daily

Mayans Cooked Food With Clay Balls

Planning a last supper party on December 21? To celebrate the Mayan way, you might need several clay balls.

That's one way the Maya cooked their food, according to U.S. archaeologists who have unearthed dozens of rounded clay pieces from a site in Mexico.

Conducted with the Instituto Nacional de Antropología e Historia (INAH) and Millsaps College's financial support, the excavation of a kitchen at Escalera al Cielo in Yucatán revealed 77 complete balls and 912 smaller fragments.

About 1-2 inches in diameter and more than 1,000 years old, the clay balls contained microscopic pieces of maize, beans, squash and other root crops.

The finding supports the hypothesis that the balls "were involved in kitchen activities related to food processing," archaeologists Stephanie Simms, Francesco Berna, of Boston University, MA, and George Bey of Millsaps College, MS, wrote in the Journal of Archaeological Science.

"This is the first time fired clay balls have been studied in the Maya area and, to my knowledge, no one has documented the use of clay balls in modern Maya cooking," Simms told Discovery News.

Located in the Puuc Maya hills of Yucatán, Escalera al Cielo was an elite residential settlement that was rapidly abandoned sometime near the end of the Terminal Classic period (800-950 A.D.), as shown by ceramic vessels, stone tools, personal adornments, and other materil assembled on the floors.

"We know much about the nature of ancient Maya kings and queens, but this type of study helps see how the Maya worked in the kitchen, what kinds of tools they used and the ways they might have prepared their cuisine," Bey, the project co-director along with archaeologist Tomás Gallareta Negrón and anthropologist William Ringle, told Discovery News.

To better understand the meaning of the fired clay balls, the researchers used a suite of microscopic techniques and experimental replication. The tests revealed that the balls were produced from local clay in a standardized set of sizes.

"They were fired at a fairly low temperature and were used repeatedly in the kitchen," Bey said.

Most likely, the fired clay balls were either placed directly into pots of food to cook or heat it, or used in pit (pib in Mayan) oven cooking installations.

"This cooking method involves digging a shallow pit, lining it with stones or clay balls, building a fire on top and waiting until it is reduced to embers," Simms said.

The process continued by placing whole roots, squash fruits or packets of food wrapped in maize on the hot stones. Everything was then covered with earth and leaves to seal in heat. Cooking took from one hour to up to a day or more.

The experimental tests showed "how the ancient Puuc Maya manipulated materials available to them to produce objects that potentially represent a staple of every Puuc Maya kitchen inventory, maybe even representing a local cooking technique and cuisine," Simms said.

Fired clay balls have been described from a variety of archaeological contexts worldwide, particularly in the Lower Mississippi River Basin and southeastern United States, and in areas of southwest Asia where clay is abundant but stone are not. Similar clay balls were also unearthed in the neolithic village of Catalhoyuk in Turkey, where they were found in hearths and interpreted as cooking or heating implements.

Read more at Discovery News

Organics Discovered on Mercury

NASA dispatched the Curiosity rover to Mars to look for organics, but a probe orbiting Mercury has beaten it to the punch.

New results from the MESSENGER spacecraft not only confirm that the planet closest to the sun has ice inside shaded craters near the north pole, but that a thin layer of very dark organic material seems to be covering a good part of the frozen water.

Both likely arrived via comets or asteroids millions -- or hundreds of millions -- of years ago.

Unlike Curiosity, which will be directly sampling Martian rocks and soils to look for signs of organic material, MESSENGER bounces laser beams and counts neutrons and gamma rays to collect information remotely about chemical elements on Mercury’s surface.

The information is correlated with detailed topographical and temperature maps, laboratory tests and computer models and then compared with candidate materials to find the best match for the observed conditions.

After years of painstaking work, scientists believe the most likely explanation is that the warmer parts of the shadowed craters contain black patches of organic material overlaying ice. The material, which is somewhat like tar, coal and soot, is believed to be similar to what has been observed on icy bodies in the outer solar system and in the nuclei of comets.

"It could easily have been delivered by comets and asteroids, along with water ice, and may even have darkened in the Mercury environment in response to the intense radiation and space weathering," lead MESSENGER scientist Sean Solomon, with Columbia University, told Discovery News.

"Certainly the darkness of the covering material was a surprise and the explanation that seems to fit all the data is that it’s organic material. It's quite interesting," Solomon said.

While there is no direct evidence the dark patches are organic materials, scientists say it is the only explanation that fits all of the conditions.

"The idea here is that this dark material was somehow cold-trapped along with the water and then the water sublimated (transformed from solid to vapor), leaving this dark deposit behind," planetary scientist David Paige, with the University of California, Los Angeles, told Discovery News.

"It's not just a crazy hypothesis and no one has got anything else that seems to fit all the observations better," Paige said.

The finding may have implications in the search for life beyond Earth. The chemistry for life, as we know it, requires organics, liquid water and a source of heat. While there is no hard evidence for liquid water on Mercury, it could exist inside the planet beneath the ice.

"It really depends on the thickness of the (ice) deposits and how long some of them have been around. As you go deeper into a planet it warms. Temperature increases with depth," Solomon said.

Over time, a barrage of impacts could have turned the surface, bringing ice to greater depths and closer to the temperatures needed to turn to liquid.

"There might be liquid water beneath some of these permanently shadowed regions," Solomon said.

In addition, scientists suspect impacts as well as solar and cosmic radiation are triggering chemical reactions in the organic material, turning it about twice as dark as Mercury's surface.

"Is there chemistry going on in some portion of the subsurface where liquid water is present, organic material is present and there’s the equivalent of geothermal energy? I think that's something we need to pursue," Solomon said.

Even if Mercury isn't a good candidate to look for ancient life, the planet may hold clues about how life got started on Earth.

Read more at Discovery News

Small Galaxy Packs Black Hole Whopper

Astronomers have found a super-super-massive black hole comprising a whopping and unprecedented 59 percent of the mass of stars in the central bulge of its host galaxy, a discovery that adds a new twist to the mysterious relationship between a galaxy and its black hole.

The black hole inside the small, compact galaxy known as NGC 1277, located about 250 million light years away in the constellation Perseus, weighs in at 17 billion times the mass of the sun.

In comparison, the supermassive black hole at the heart of our Milky Way galaxy is equal to the mass of about 4 million suns.

Typically, black holes account for 0.1 percent of a galaxy's stellar bulge. Until now, the galaxy with the proportionally largest black hole was NCG 4486B, which has a black hole accounting for 11 percent of the combined mass of the central stars.

How 1277's black hole came to be so large is mystery.

"We didn't expect these systems to exist at all, but because the stars move so incredibly fast in the centers of these objects, we know these big black holes exist in these small galaxies," astronomer Remco van den Bosch, with the Max Planck Institute for Astronomy in Germany, wrote in an email to Discovery News.

"Now that we have found that these crazy kind of galaxies exist, we want to know how they form and how (un-)common they are," he wrote.

However the galaxy and its black hole came to cohabitate, they've been together and in relative peace for a long, long time.

The galaxy has a flat disk, indicating its stars are, and have been, relatively undisturbed for eons. If the black hole had been feeding, the flux of infalling material would have triggered new star formation, van den Bosch said.

"This black hole -- and galaxy -- must have formed in its final form fairly quickly after the big bang. We do not have any information on whether the black hole formed before the galaxy, but most likely it happened at the same time," van den Bosch wrote.

Read more at Discovery News

Bizarre Insectlike Creatures Found in Spanish Cave

Three bizarre-looking springtails, tiny insectlike creatures, have been discovered in a Spanish cave.

Springtails are amongst the most ancient and widespread animals on the planet. Like insects, they have six legs, but are small, more primitive and lack wings. They usually have a furca, or a tail used to spring away from danger, hence the name "springtails." Many cannot be seen with the naked eye; the largest species is about 0.24 inches long (6 millimeters).

The three species — dubbed Pygmarrhopalites maestrazgoensis, P. cantavetulae and Oncopodura fadriquei — are very different from one another. But each of the new species has the requisite springy tails and hairy, tiny bodies, resembling Lilliputian monsters. One of them, O. fadriquei, lacks eyes.

They were found by researchers from Spain's University of Navarra in the isolated Maestrazgo caves in the Teruel region of Spain, at elevations up to 6,560 feet (2,000 meters). Outside the isolated caves, winter temperatures drop to minus 40 degrees Fahrenheit (minus 40 degrees Celsius). Inside, however, temperatures stay between 41 and 54 F (5 to 11 C).

The scientists plan to study how these creatures adapt to the cold, wet and lightless conditions in the cave, according to a release from the Spanish Foundation for Science and Technology.

"Like other cave-adapted animals, the [springtails] require greater chemical sensitivity as they cannot use their sight in the absence of light," said University of Navarra researcher Enrique Baquero in the statement.

Read more at Discovery News

LHC Creates New Form of Matter

Collisions between particles inside the Large Hadron Collider atom smasher have created what looks like a new form of matter.

The new kind of matter is called color-glass condensate, and is a liquidlike wave of gluons, which are elementary particles related to the strong force that sticks quarks together inside protons and neutrons (hence they are like "glue").

Scientists didn't expect this kind of matter would result from the type of particle collisions going on at the Large Hadron Collider at the time. However, it may explain some odd behavior seen inside the machine, which is a giant loop where particles race around underneath Switzerland and France.

When scientists sped up protons (one of the building blocks of atoms) and lead ions (lead atoms, which contain 82 protons each, stripped of their electrons), and crashed them into each other, the resulting explosions liquefied those particles and gave rise to new particles in their wake. Most of these new particles, as expected, fly off in all directions at close to the speed of light.

But recently scientists noticed that some pairs of particles were flying off from the collision point in correlated directions.

"Somehow they fly at the same direction even though it's not clear how they can communicate their direction with one another. That has surprised many people, including us," MIT physicist Gunther Roland, whose group led the analysis of the collision data along with Wei Liof Rice University, said in a statement.

A similar flight pattern is seen when two heavy particles, such as lead and lead, crash into each other. In this case, the collisions create what's called quark-gluon plasma -- a superhot soup of particles similar tothe state of the universe just after the Big Bang. This soup can sweep particles in the same direction, explaining why their flight directions would be correlated.

But quark-gluon plasma isn't possible with lead-proton collisions, like the ones in the new study. Now researchers think a different state of matter, the color-glass condensate, may act in a similar way. The color-glass condensate's dense swarm of gluons may also sweep particles off in the same direction, suggested Brookhaven National Laboratory physicist Raju Venugopalan, who first predicted the substance, which may also be seen after proton-proton collisions.

The mechanism may depend on a weird quirk of particles called quantum entanglement. Two particles can be entangled so that they retain a connection even after they are separated, and an action on one reverberates on the other.

Entangled gluons in the color-glass condensate could explain how particles flying away from the collision point might share information about their flight direction with each other, Venugopalan said.

Read more at Discovery News

Human Poo Leaves Archeological Stain in Norway

Human feces are smeared all over the geological record of places people have inhabited. The chemical signature of human excrement was analyzed in sediments in a northern Norwegian lake. Starting around 2,250 years ago, the presence of people’s poo painted a picture of human population changes in the region around Lake Liland on one of the Lofoten Islands.

"Without even knowing it, early settlers were recording their history for us, and in the most unlikely of ways, in their poop,” said study author Robert D’Anjou, University of Massachusetts geosciences doctoral student. “The prehistoric settlers and their livestock pooped and their feces washed into the lake, which over time left a record of trace amounts of specific molecules that are only produced in the intestines of higher mammals. When you find these molecules at certain concentrations and in specific ratios, it provides an unmistakable indicator that people were living in the area."

The chemical coprostanol is produced during the digestion of cholesterol in the human gut. The chemical collects in sediments after people’s feces are flushed into bodies of water. The sediments provided evidence that from 7,300 years ago to 2,250 years ago, the region had no observable human habitation. Human and domesticated animals’ fecal signatures began showing up after that time. Two different molecular markers were also used to look for evidence of forest clearing through burning.

Population density was low in the region for much of its history, until reaching a peak in 500 A.D. A low spot in 850 suggested the area was depopulated at that time. Human presence fluctuated until dropping to another low spot in 1750.

Read more at Discovery News

Climate Change Threatens French Truffle

Scientists said on Tuesday they had proof that climate change was hitting the Perigord black truffle, a delight of gourmets around the world.

Trufflers have long suspected that global warming is affecting Tuber melanosporum, dubbed "the black diamond" on account of its color and extraordinary price, in its native habitat in southwestern France, Spain, and Italy.

A century ago, French trufflers notched up a harvest that, according to legend, reached 1,000 tonnes in a year.

In the 1960s, truffle yields were still 200-300 tonnes annually.

But in recent years, they have been a meager 25 tonnes or so, prompting retail prices to rocket to as high as 2,000 euros ($2,500) a kilo.

In a letter to the journal Nature Climate Change, Swiss scientists said they now had clear data that drier summers were to blame, as this affected the oak and hazelnut trees on which the prized fungi grows, a process known as symbiosis.

The team found that harvests in France's Perigord and in Spain's Aragon region fell at roughly the same pace from 1970-2006, and this trend was in line with an overall decline in summer rainfall.

Harvests in northern Italy's Piedmont and Umbria also retreated, but not as badly as in France and Spain, and this correlated with relatively higher levels of summer rain in those regions.

Harvesting of the black truffle, also called the Mediterranean truffle, is restricted to the months between November and February.

However, the success of the yield depends on the summer's weather, explained Ulf Buentgen and Simon Egli from the Swiss Federal Research Institute, or WSL.

Truffles thrive in wet and cold conditions and hate dryness and heat.

"Given the symbiotic fungi-host association, we postulate that competition for summer soil moisture... might be a critical factor for truffle fruit body production, particularly in semi-arid environments," they said.

Their theory, they added, is borne out by research in Spain, which found that oak tree growth depends overwhelmingly on rain between May and July.

Read more at Discovery News

1,000-Year-Old Muslim Joke Book Found

An 11th-century book by a revered Baghdad Muslim scholar turns out to be a tongue-in-cheek guide for party crashers, according to the researcher who translated the book into English.

The tome was originally authored by al-Khatib al-Baghdadi, a well known scholar of the Prophet Mohammed's teachings.

According to Emily Selove of the University of Manchester, who did the translation, he wrote the book to remind readers "that every serious minded person needs to take a break."

She continued, "This book, which contains flirtation, profanity, and even a little drunkenness, is a lot of fun and offers a rather different perspective to the austere image Islam has from that period. The reality is that the Baghdad of 1,000 years ago was actually rather Bohemian -- it wasn't perfect by any means -- but not the violent and repressive society you might imagine it was."

"Such ignorance is probably down to the fact that so little of the huge body of literature produced at that time has been translated into English. There's so much more to do."

Selove, however, added, "Though it's light and really quite an enjoyable read, there are serious messages too. The book is about generosity and encouraging individuals to express themselves eloquently and clearly."

"It also suggests that turning a hungry person away from a place laden with food was cruel -- as food was sometimes in short supply to the poor. It castigated those who turned gate crashers away from parties as misers. You do not turn people away if they are hungry."

Humor, though, is peppered through the book. It even contains a piece of satire: a fictional document commissioned by a Caliph on the creation of a "Government office for Gatecrashing."

Jokes

Here are some of the jokes:

Once a man crashed another man's party. "Who are you?" the host asked him. "I'm the one who saved you the trouble of sending an invitation!" he replied.

A party-crasher walked into a gathering, and they said to him, "Nobody invited you!" "But if you didn't invite me and I didn't come," he replied, "think how lonely that would be!"

Once a party-crasher walked in the house of a man who had invited a gathering of people. "Hey, you!" the man said. "Did I say you could come?" "Did you say I couldn't come?" the party crasher replied.

Someone asked a party-crasher, "What's four times four?" "Sixteen loaves of bread," he said. "What is two times two?" "Four loaves of bread," he replied. And another time he said, "I waited the amount of time it takes someone to eat a loaf of bread."

Bunan (a popular rogue at the time that Selove likens to a cross between Falstaff and Robin Hood) had eaten and eaten well, and someone said to him, "Slow down! You'll kill yourself!" "If it is time to die," Bunan replied, "I want to go well fed and well watered, not parched and hungry."

A party-crasher took up with a man while traveling. One day the man said to him, "“Go and buy some meat for us." "No, by God, I don't have the means," said the party-crasher. So the man went and bought the meat. Then he said, "Get up and cook it." "I'm no good at cooking," said the party-crasher. So the man cooked the meat. Then he said, "Get up and sop the bread," and the party-crasher replied, "By God, I feel exhausted." So the man sopped the bread. Then he said, "Get up and ladle the stew." "I'm afraid I'll spill it on my robe," said the party-crasher, so the man ladled the stew. "Get up and eat," he said. "By God," said the party-crasher, "I've been feeling bad for refusing you so many times," and he came forward and ate.

Advice

The book also contains advice:

A man said to Bunan, "Counsel me!"

"Don't fraternize," he replied, "but if you can't avoid it, pick someone who won't pester you. Don't go for greens, gorge on chicken skin, stuff yourself with goat kidneys, gulp bird gizzards, snatch fish innards, or concern yourself with the eyeballs if a head is served. And pay no attention to skinny poultry. Think of naught but what is in your plate, nor glance upon the plates of the others. And if the roast goat when passed to you has little meat left on it, pity not the weakness of the aged guests, nor the greed of the young. Eat, and don't bother yourself with the host's family, and don't waste time inquiring after their health."

Read more at Discovery News

Can You Crack The Pigeon's Code?

A coded message found attached to the remains of a hero D-Day carrier pigeon may never be cracked, British top codebreakers have admitted.

Hand-written on a small sheet of paper headed "Pigeon Service," the message was found in a red cylinder still attached to the bird's leg bone.

The pigeon's skeleton emerged in 1982 from the chimney of 17th-century home in Bletchingley, Surrey, when the home's current owner David Martin decided to restore the fireplace.

Unseen for three decades, the message was handed last month to intelligence agents at the GCHQ (Government Communications Headquarters) in the hope it could be deciphered.

But the 27-code cryptographic puzzle has stumped Britain's renowed code-breakers.

The experts had to admit the pigeon may have taken its secret to the grave since the coded message can't be cracked without its codebook.

"Unfortunately, much of the vital information that would indicate the context of the message is missing," Bletchley Park, a center where, during World War II, top secret codebreaking work was carried out on behalf of the Allies, said in a statement.

Historians believe the bird was dispatched from Nazi-occupied France on June 6 1944, during the D-Day invasions.

Because of Churchill's radio blackout, homing pigeons were taken on the D-Day invasion and released by Allied Forces to inform military generals back on English shores how the operation was going.

The military pigeons were dropped behind enemy lines from bombers, whereupon resistance fighters picked them up, before releasing them homeward bound with top secret messages.

The brave birds played a very active role in World War II (the RAF trained 250,000 birds, forming the National Pigeon Service) and, between 1943 and 1949, 32 were awarded the Dickin Medal, Britain's highest possible decoration for valor given to animals.

The British spy pigeon either got lost, disorientated in bad weather, or was simply exhausted after flying for hundreds of miles. Experts speculate the bird might have attempted to rest on an open chimney, but was overcome by fumes from a fire below and he died.

It is possible the pigeon was destined for the top secret Bletchley Park, which was just 80 miles from Mr. Martin's home. Now a museum, Bletchley Park is where codebreakers worked around the clock to crack the Nazi's "unbreakable" Enigma code.

People from all over the world are now trying to decipher the baffling message.

Sent to "XO2" at 16:45, it reads:

AOAKN HVPKD FNFJW YIDDC

RQXSR DJHFP GOVFN MIAPX

PABUZ WYYNP CMPNW HJRZH

NLXKG MEMKK ONOIB AKEEQ

WAOTA RBQRH DJOFM TPZEH

LKXGH RGGHT JRZCQ FNKTQ

KLDTS FQIRW AOAKN 27 1525/6

Signed "Sjt W Stot," the message features two more codes at the end: NURP.40.TW.194 and NURP.37.OK.76.

GCHQ experts believe that one of them could be the identity of the pigeon in the chimney.

The first group of letters indicated the bird's origin ("NURP" stands for National Union of Racing Pigeons), while the following two-digit number attested its year of registration (40 refers to 1940).The final set of numbers identified the specific pigeon and the area of the country it was from.

Nothing is known of "Sergeant W Stot." The meaning of the message's destination -- "X02" -- is also cryptic.

"During the war, the methods used to encode messages naturally needed to be as secure as possible and various methods were used," experts at Bletchley Park said.

"The senders would often have specialist codebooks in which each code group of four or five letters had a meaning relevant to a specific operation, allowing much information to be sent in a short message," they added.

The code groups could then themselves be encrypted using a one-time pad. With this system, a random key was used to encrypt only one message.

"The advantage of this system is that, if used correctly, it is unbreakable as long as the key is kept secret. The disadvantage is that both the sending and receiving parties need to have access to the same key, which usually means producing and sharing a large keypad in advance," Bletchley Park said.

The GCHQ experts believe the pigeon's message, which contained 27 codes, each made up of five letters or numbers, was encrypted with the "one-time pad" system.

"This means that without access to the relevant codebooks and details of any additional encryption used, it will remain impossible to decrypt the message," they said.

The only way to crack the code relies in finding one of those WWII codebooks, normally destroyed once no longer in use, and in veteran codebreakers who during the war worked at Bletchley Park or in military signals.

"If 'Sjt Stot' and addressee X02 could be identified, it could give us a better idea of where to look for the information," Bletchley Park said.

Read more at Discovery News

Mystery of Florida Keys Shipwreck Solved

For more than 100 years, the sunken ship off Key Largo, Fla., was merely known as "Mike's Wreck," named after the employee of a local dive shop. But a team of archaeologists have finally identified the ship that sunk here in 1911 as the Hannah M. Bell, built in England in 1893.

The vessel once hauled sugar, cotton and other cargo between Europe, the United States and South America, according to a statement from the Florida Keys National Marine Sanctuary, where the Hannah M. Bell rests.

The 315-foot (96 meter) steamship ran aground on a shallow reef known today as Elbow Reef, located about 6 miles (10 kilometers) off Key Largo, on April 4, 1911. The vessel was loaded with coal bound for Vera Cruz, Mexico. For days, salvagers tried to rescue the Hannah M. Bell, but gave up after its holds filled with water, according to the statement. By May, waves had torn the ship apart and left its remnants in shallow water, making it accessible and visible today only to snorkelers and scuba divers.

A team of maritime archaeologists took an expedition to the wreck in September, after which they positively identified the ship.

"Similar to the way detectives use forensic information to solve a crime, we compared the dimensions and construction characteristics of the shipwreck known locally as 'Mike's Wreck' with historic shipping records in order to solve this mystery," said Matthew Lawrence, a maritime archeologist, in a statement from the sanctuary.  "Measurements of the shipwreck and the records for Hannah M. Bell were virtually identical, as were the reported sinking location and the actual location of the wreck."

The steamship was built by Ropner and Son in England and named for the woman who christened it, according to the release.

The Florida Key's shallow coral reefs have claimed many ships over the years, and helped spawn a once-thriving salvaging industry, in which people would reclaim and repair marooned ships and their cargo, both legally and otherwise.

Read more at Discovery News

Ancient Microbes Found in Buried Antarctic Lake

Beneath the icy surface of a buried Antarctic lake, in super-salty water devoid of light and oxygen that is also cold enough to freeze seawater, researchers have now discovered that a diverse community of bacteria has survived for millennia.

The findings shed light on the extreme limits at which life can live not just on Earth, but possibly alien worlds, scientists added.

Researchers analyzed Lake Vida, which lies encapsulated within ice at least 60 feet (18 meters) beneath Antarctica's surface. Past studies revealed the brine in the lake has been isolated from the surface for at least 2,800 years.

"That ice is so thick, nothing from the outside can get down to the water naturally,"researcher Peter Doran, an earth scientist at the University of Illinois at Chicago, said from a research outpost on Antarctica.

 To examine the brine, the researchers used drills and heated pipes to delve downward. To avoid contaminating this isolated ecosystem, researchers set up a "clean room" on top of the hole, wearing the type of white suits used in electronics and germ labs to keep conditions as sterile and free of contamination as possible.

"Doing all this in the cold of Antarctica is pretty tough," Doran said.

Life finds a way

The brine ranges from yellow to orange in color due to iron-laced compounds within it. The investigators found the temperature of the water was about 8 degrees Fahrenheit (minus 13 degrees Celsius) — its saltiness, about five to six times greater than average ocean water, keeps it from freezing like freshwater or seawater would. It is also completely depleted of oxygen and mildly acidic.

But despite the tough set of conditions, the researchers found the diverse and thriving community of microbes in the brine.

"What's most surprising is that there's anything living down there — it's a pretty harsh environment for life to take hold," Doran told OurAmazingPlanet. "There's a mantra that goes, 'wherever on Earth you find water, you find life,' and this is another one of those examples."

The brine had very high levels of carbon-based compounds, the building blocks of life. It also possessed high levels of chemicals that generally react with each other, such as nitrous oxide and molecular hydrogen, suggesting they were being regularly replenished — a surprising discovery, given how the lake was isolated for millennia from any obvious external sources of energy to help create them.

The overall chemistry of this brine suggests that chemical reactions between the water and the underlying sediment generated the reactive chemicals seen in the brine. The molecular hydrogen seen in the brine might serve as a fuel source to help support its microbial life, researchers added.

Alien implications

Similar habitats may exist on icy alien worlds, researchers said.

"By seeing what the boundaries of life are on Earth, that helps us when we go out and look for examples elsewhere," Doran said. "Years ago, we never would have thought to look for life in the sub-surface of Mars, and now we have examples on Earth that things can live down there."

Future research can explore Lake Vida's depth. "We'd like to collect samples of the bottom sediments down there, which can help us figure out this lake's history," Doran said. "When did it form? Was it always like this?"

Read more at Discovery News

Did You See That? How Could You Miss It?

You may have received CPR training some time ago, but would you remember the proper technique in an emergency? Would you know what to do in the event of an earthquake or a fire? A new UCLA psychology study shows that people often do not recall things they have seen -- or at least walked by -- hundreds of times.

For the study, 54 people who work in the same building were asked if they knew the location of the fire extinguisher nearest their office. While many of the participants had worked in their offices for years and had passed the bright red extinguishers several times a day, only 13 out of the 54 -- 24 percent -- knew the location.

When asked to find a fire extinguisher, however, everyone was able to do so within a few seconds; most were surprised they had never noticed them. The researchers found no significant differences between men and women, or between older and younger adults.

"Just because we've seen something many times doesn't mean we remember it or even notice it," said Alan Castel, an associate professor of psychology at UCLA and lead author of the study. "If I asked you to draw the front of a dime or the front of a dollar bill from memory, how well could you do that? You might get some elements right. Do you know who the president is? On the dime, is he facing left or right? Does it say 'In God We Trust' on the front of the dollar or the back? Do you know what else it says? You've seen it so many times, but you probably haven't paid much attention to it."

Castel said that not noticing things isn't necessarily bad, particularly when those things are not important in your daily life. "It might be a good thing not to burden your memory with information that is not relevant to you," he said.

But with safety information, such as knowing where fire extinguishers are or what to do in an emergency, being prepared can, of course, be very useful.

"When you're on an airplane, do you know where the life vest is and what to do in the event of an emergency?" Castel asked. "You've been told many times, but how would you respond under stressful conditions, when there could be smoke and people screaming?"

A few months after being asked the location of the nearest fire extinguisher, the study participants were asked again if they knew where the closest one was. All of them knew.

"We don't notice something if we're attending to something else," Castel said. "Fire extinguishers are bright red and very conspicuous, but we're almost blind to them until they become relevant."

What does this tell us about the importance of training, whether for emergencies or something as common as learning a new computer program?

Castel stresses that making errors during training is useful. As with the fire extinguisher exercise, errors -- or simple oversights -- can teach us that we don't know something well and need to pay more attention in order to remember it.

"It's good if errors happen during training and not during an event where you need the information," he said. "That's part of the learning process."

The study is published in the journal Attention, Perception, & Psychophysics.

Read more at Science Daily

Earth's 'Hum' Helps Probe Planet's Interior

The global "hum" of the Earth is now helping geophysicists probe the planet's deep interior, a group of researchers say.

Since this hum — called seismic noise, which is generated by sources such as storm-driven ocean waves — is detectable everywhere on Earth, it could help scientists analyze the innards of the planet worldwide, investigators added in a new study detailed in the Nov. 23 issue of the journal Science.

Traditionally, researchers peer into the interior of the Earth by analyzing seismic waves generated by earthquakes. The way seismic waves zip through the planet depends on physical properties of the Earth's innards, such as rock composition, temperature and pressure. As such, the way the waves behave offers useful clues about details of Earth's geology that are otherwise largely hidden from view.

"With these waves, seismologists produce images in a way similar to medical imaging," researcher Michel Campillo, a seismologist at Joseph Fourier University in Grenoble, France, told OurAmazingPlanet.

The problem with this strategy is that it depends on earthquakes. "Large earthquakes are rare —fortunately!" Campillo said. Quakes also mostly recur in specific places, which leads to some areas being imaged well but leaving others relatively obscure.

In addition to seismic waves from earthquakes, the interior of the Earth is pervaded by seismic noise, a collective hum resulting from the bombardment of Earth's surface by a variety of sources, such as the swelling of oceans during storms.

"The noise was regarded as useless and even problematic since it hides slight earthquake signals," Campillo said.

Tracking noise

However, in recent years, by analyzing large amounts of seismic data collected over time, investigators successfully followed ambient seismic noise waves as they rippled across Earth's surface. Now scientists reveal they can also use ambient noise to image Earth's deep interior. The advantage of this strategy is that "ambient noise imaging can be applied in regions without earthquakes," Campillo said.

The scientists installed 42 seismic recording stations in northern Finland and compared seismic noise signals between each station. By filtering out earthquake signals and ambient seismic noise surface waves, they were able to reconstruct how ambient seismic noise rippled through the Earth.

"Finland was a good place because it is a place with very old and homogeneous crust," Campillo said. Its old age meant it had little in the way of new activity to confuse readings, while its uniform nature meant there was little diversity of material to complicate findings.

Geo toolbox

Using this data, the researchers imaged the transition zone separating the upper and lower layers of the Earth's mantle, the main layer just below Earth's crust. The top of the mantle was about 9 miles (15 kilometers) thick and 255 miles (410 km) from the Earth's surface, while its bottom was about 2.5 miles (4 km) thick and 410 miles (660 km) from the Earth's surface. The differences between top and bottom are due to changes in crystal structure resulting from how pressure varies according to depth.

"These changes of microstructures result in increase of seismic speeds, which we eventually detect when waves are reflected on the layers where they occur," Campillo said.

Read more at Discovery News

What Happens If the Mississippi Runs Dry?

The Mississippi River soon may be too shallow for barge shipping, which could hurt international trade and cause increases in domestic energy and food costs. Switching to other shipping methods could increase pollution.

However, there may be a bright side: Drought and reduced traffic on the desiccated rivers may benefit wildlife in the long run.

Last Friday, the Army Corps of Engineers began reducing the flow of water into the Missouri River from the Gavins Point Dam in South Dakota because of the continuing drought in the central United States. The Missouri is a major tributary of the Mississippi River, which means reduced flow in the Missouri results in a further drop in water levels on the Mississippi.

A crucial point in the river between St. Louis, Mo., and Cairo, Ill., may become impassible by approximately Dec. 10, according to a press release from the American Waterways Operators and the Waterways Council Inc., two organizations representing river shipping industry interests.

Trade in some of the most important commodities in America, such as coal and grain, stand to suffer from the stoppage of transport on America's main aquatic artery.

"For the coal that travels on the Mississippi, there could be impacts and delays in getting it to consumers in a timely way," Debra Colbert, senior vice president of Waterways Council, Inc., told Discovery News. "It will cost more to ship it by rail and or truck and consumers will pay more for heating and electricity as a result."

The exact effect on prices is impossible to estimate at this point, Colbert said.

Delays would affect 3.8 million tons of coal, according to the shipping organization's press release. Five million barrels of crude oil would be delayed, which may necessitate the import of $545 million worth of foreign crude. All together, $7 billion in commodities may be delayed.

Delays and cost increases in American grain shipments could affect the global food supply.

"River barge shipping is all geared to moving bulk grain exports for (livestock) feed uses overseas," said Bruce Abbe, executive director of the Midwest Shippers Association. " A huge share of the global market is served by American agriculture. Barge or water shipping is considered the most cost- efficient means for moving large quantities of bulk grains.

"If the drought continues more into next year, a larger percentage might go to the Pacific Northwest export terminals by rail," said Abbe. "Rail also can and does carry grain from the Midwest down to the Gulf."

Switching to rail and truck transport will affect American farmers' incomes and global consumer prices, Abbe noted.

"Cost will go up overall, for export customers and for suppliers here," said Abbe.

Along with increased costs, increased shipping via rail and truck also results in more pollution. Research by the U.S. Maritime Administration and the National Waterways Foundation calculated that:

• Inland waterway barge towing produces 19.27 tons of greenhouse gases per million tons of freight moved one mile, a unit known as a ton-mile.
• Container trucks produce 71.61 tons of greenhouse gases per million ton-miles.
• Rail transports produces 26.88 tons of greenhouse gases per million ton-miles.

On the other hand, the drought on the Mississippi might not be entirely negative for the environment.

Shipping causes localized disturbance to the Mississippi river's ecosystem as the barges and tugboats churn the water with their wakes and propellers, which can be six feet in diameter, according to Jon Duyvejonck, a biologist with the U.S. Fish and Wildlife Service.

During normal river levels, the turbulent waters and waves produced by ships can uproots plants in the loose, mucky soil of the river banks. A drought benefits the river by giving sediments on the river banks a chance to settle and form denser soil. After a drought, plants can become more resistant to the disturbance caused by boats. Duyvejonck noted that after a drought, a burst of plant growth in the solidified soil often proves to be a boon for wildlife.

Winter is a particularly beneficial time to reduce river traffic, Duyvejonck said.

"In winter, cold-blooded fish seek to reduce energy expenditure by resting in still waters," said Duyvejonck. "When ships pass, the fish must fight the erratic currents. Hence, a slowdown in traffic during December could help fish save energy and possibly result in an improvement in overwinter survival."

One ecological danger from ship traffic in low water is to mussels, which can't move out of the way of ships traveling through low waters. However, the ships themselves are not the biggest environmental problem caused by keeping the rivers open to transport during a drought. Duyvejonck said that finding a place to put the sand and silt dredged from the river's main channels can be the biggest environmental headache.

The Army Corps of Engineers began dredging ahead of schedule this year to battle the drought conditions, but were prepared for the low water this year by the flood last year, according to Mike Petersen, public affairs chief for the U.S. Army Corps of Engineers' St. Louis District.

"During the flood, Congress approved funds for river maintenance, so we had already done a significant amount of work dredging channels," said Petersen. "This year we have only needed two dredging ships working on the river, compared to the eight we had working during the drought of 1988 and '89."

Read more at Discovery News

The Google Earth Island That Never Existed

A South Pacific island identified on Google Earth and world maps does not exist, according to Australian scientists who went searching for the mystery landmass during a geological expedition.

The sizable phantom island in the Coral Sea is shown as Sandy Island on Google Earth and Google maps and is supposedly midway between Australia and the French-governed New Caledonia.

The Times Atlas of the World appears to identify it as Sable Island. Weather maps used by the Southern Surveyor, an Australian maritime research vessel, also say it exists, according to Dr Maria Seton.

But when the Southern Surveyor, which was tasked with identifying fragments of the Australian continental crust submerged in the Coral Sea, steamed to where it was supposed to be, it was nowhere to be found.

"We wanted to check it out because the navigation charts on board the ship showed a water depth of 1,400 meters (4,620 feet) in that area -- very deep," Seton, from the University of Sydney, told AFP after the 25-day voyage.

"It's on Google Earth and other maps so we went to check and there was no island. We're really puzzled. It's quite bizarre.

"How did it find its way onto the maps? We just don't know, but we plan to follow up and find out."

News of the invisible island sparked debate on social media, with tweeter Charlie Loyd outpointing that Sandy Island is also on Yahoo Maps as well as Bing Maps "but it disappears up close".

On www.abovetopsecret.com, discussions were robust with one poster claiming he had confirmed with the French hydrographic office that it was indeed a phantom island and was supposed to have been removed from charts in 1979.

Another claimed: "Many mapmakers put in deliberate but unobtrusive and non-obvious 'mistakes' into their maps so that they can know when somebody steals the map data."

Google was not immediately available for comment. But the Google Maps product manager for Australia and New Zealand told the Sydney Morning Herald a variety of authoritative public and commercial sources were used in building maps.

Read more at Discovery News

Myth Debunked: Full Moon Does Not Increase Incidence of Psychological Problems

Contrary to popular belief, there is no connection between lunar phases and the incidence of psychological problems. This is the conclusion reached by a team of researchers directed by Professor Geneviève Belleville of Université Laval's School of Psychology after having examined the relationship between the moon's phases and the number of patients who show up at hospital emergency rooms experiencing psychological problems.

Details on the study can be found on the website of the scientific journal General Hospital Psychiatry.

To determine whether the widespread belief linking the moon to mental health problems was true, researchers evaluated patients who visited emergency rooms at Montreal's Sacré-Coeur Hospital and Hôtel-Dieu de Lévis between March 2005 and April 2008. They focused specifically on 771 individuals who showed up at the emergency room with chest pains for which no medical cause could be determined. Psychological evaluations revealed that a sizeable number of these patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

Using lunar calendars, the researchers determined the moon phase in which each of these visits occurred. The results of their analyses revealed no link between the incidence of psychological problems and the four lunar phases. There was one exception, however; anxiety disorders were 32% less frequent during the last lunar quarter. "This may be coincidental or due to factors we did not take into account," suggested Geneviève Belleville. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

This study's conclusions run contrary to what many believe, including 80% of nurses and 64% of doctors who are convinced that the lunar cycle affects patients' mental health. "We hope our results will encourage health professionals to put that idea to rest," said Dr. Belleville. "Otherwise, this misperception could, on the one hand, color their judgment during the full moon phase; or, on the other hand, make them less attentive to psychological problems that surface during the remainder of the month."

Read more at Science Daily

Large Mars Dust Storm is Brewing

A NASA spacecraft is keeping tabs on a vast dust storm on Mars that has spawned changes in the Martian atmosphere felt by two rovers on the planet's surface.

The Martian dust storm was first spotted by NASA's Mars Reconnaissance Orbiter (MRO) on Nov. 10 and has been tracked ever since. The agency's Mars rover Opportunity has seen a slight drop in atmospheric clarity due to the storm. Meanwhile the newer Curiosity rover -- which has a built-in weather station -- has seen a drop in air pressure and slightly increased nighttime temperatures halfway around the planet from Opportunity, NASA officials said.

"This is now a regional dust storm," Rich Zurek, NASA's chief Mars scientist at the Jet Propulsion Laboratory in Pasadena, Calif., said in a statement Wednesday (Nov. 21). "It has covered a fairly extensive region with its dust haze and it is in a part of the planet were some regional storms have grown into global dust hazes."

NASA is combining observations by the Curiosity rover and MRO to create a complete picture of the Martian dust storm. The Spain-built Rover Environmental Monitoring Station on Curiosity gives scientists a real-time look at conditions over the rover's position inside Gale Crater.

The Mars Color Imager on MRO was built by Malin Space Science Systems in San Diego. It was Malin's Bruce Cantor who first spotted the storm in photos from the powerful Mars camera on Nov. 10.

"For the first time since the Viking missions of the 1970s, we are studying a regional dust storm both from orbit and with a weather station on the surface," Zurek said.

Because the dust from the current storm is absorbing sunlight instead of reflecting it, a warming effect 16 miles (25 kilometers) above the Martian tempest has been seen by MRO. The effect, first recorded by MRO's Mars Climate Sounder on Nov. 16, has led to a temperature increase of 45 degrees Fahrenheit (25 degrees Celsius) so far.

Warmer temperatures are not confined to the Martian south. The circulation of the Martian atmosphere has also led to a hot spot in the planet's northern polar regions. The temperature on Mars is typically about minus 80 degrees F (minus 60 degrees C), but can vary depending on location and the Martian season.

Regional dust storms on Mars were observed in 2001 and 2007, but not between those years or in the time since. The Martian year lasts two Earth years, with major dust storm events following a seasonal pattern. Dust storm season on Mars began a few weeks ago as the Martian spring began in the planet's southern hemisphere, NASA officials said.

"One thing we want to learn is why do some Martian dust storm get to this size and stop growing, while others this size keep growing and go global," Zurek said.

A global dust storm on Mars could have implications for the Opportunity and Curiosity rovers. If the current dust storm were to expand to cover the Red Planet, the dust settling on Opportunity's solar panels could reduce the rover's power supply. Opportunity has been exploring the plains of Meridiani Planum since its 2004 landing on Mars.

Read more at Discovery News