Dec 14, 2012
The findings support previous studies of dogs detecting various types of cancer and could have great potential for screening hospital wards to help prevent C. difficile outbreaks, say the researchers.
C. difficile infection most commonly occurs in older people who have recently had a course of antibiotics in hospital, but it can also start in the community, especially in care homes. Symptoms can range from mild diarrhoea to a life-threatening inflammation of the bowel.
Early detection is vital to prevent transmission, but diagnostic tests can be expensive and slow, which can delay treatment for up to a week.
Diarrhoea due to C. difficile has a specific smell, and dogs have a superior sense of smell compared with humans. This prompted researchers in the Netherlands to investigate whether a dog could be trained to detect C. difficile.
A two-year old male beagle (called Cliff) was trained by a professional instructor to identify C. difficile in stool samples and in patients with C. difficile infection. He was taught to indicate the presence of the specific scent by sitting or lying down.
The dog had not been trained for detection purposes before.
After two months of training, the dog's detection abilities were formally tested on 50 C. difficile positive and 50 C. difficile negative stool samples. He correctly identified all 50 positive samples and 47 out of 50 negative samples.
This equates to 100% sensitivity and 94% specificity (sensitivity measures the proportion of positives correctly identified, while specificity measures the proportion of negatives correctly identified).
The dog was then taken onto two hospital wards to test his detection abilities in patients. He correctly identified 25 out of 30 cases (sensitivity 83%) and 265 out of 270 negative controls (specificity 98%).
The researchers add that the dog was quick and efficient, screening a complete hospital ward for the presence of patients with C. difficile infection in less than 10 minutes.
They point to some study limitations, such as the unpredictability of using an animal as a diagnostic tool and the potential for spreading infections via the dog, and say some unanswered questions remain.
Read more at Science Daily
Ever since physicists found a particle that looks very much like the Higgs boson in July, they have been probing its properties, essentially running their experimental hands all over it to check out its features. They do this by smashing protons together at insanely high speeds in the Large Hadron Collider and watching the resulting rain of particles that gets produced. Within this melee, several Higgs bosons appear and almost immediately decay into other particles.
The LHC can detect the Higgs decaying in two different ways. One channel produces two characteristic photons while another creates four particles known as leptons. The two decay paths each give scientists a distinct value for the mass of the Higgs. But there’s a little problem.
“There turns out to be a slight tension between the two masses,” said physicist Beate Heinemann of the University of California, Berkeley, who works on ATLAS, one of the LHC’s Higgs-searching experiments. “They are compatible, just not super compatible.”
The two photon channel is saying that the Higgs mass is 126.6 gigaelectronvolts (GeV), or about 126 times the mass of a proton. The four lepton decay route suggests the mass is 123.5 GeV. A very tiny disagreement that is nonetheless very strange because the Higgs should have one identifiable mass. ATLAS scientists noticed the discrepancy in their data previously and thought it might simply be a problem with calibrating their machinery. Yet even after calibration and analyzing more data, the difference remained.
Several physics blogs have noted that one way to explain this would be to have two different Higgs bosons, each with a very similar mass. This would be a truly bizarre and unexpected result. But it’s much more probable that scientists are seeing a statistical mirage.
Heinemann said the four lepton channel has only analyzed about 10 Higgs bosons and the two photon channel about 500 Higgs. Physicists need to see the same result over and over in thousands or even millions of particle events before they are sure it’s not just a statistical coincidence. “The most likely explanation is that it’s one particle,” said Heinemann.
Read more at Wired Science
Titled "Tællelyset" (The Tallow Candle), the ink-written manuscript was found by local historian Esben Brage at the bottom of an archive box. Brage made the discovery in October in the historical archive on the island of Funen, where the Danish author was born.
Two months later, historians confirmed that the six-page manuscript was indeed written by Andersen. They dated the document to the mid-1820s, when the writer was in his late teens.
"I am in no doubt that it has been written by Andersen," Ejnar Stig Askgaard of the Odense City Museum told the Danish daily Politiken.
The newspaper has translated and published a version of the story in English.
The front page of the document reads "To Madam Bunkeflod from her devoted H.C. Andersen."
A vicar’s widow, Mme Bunkeflod lived opposite Andersen’s childhood home. Historians know that the writer visited her often as a child, borrowing her books.
"The fairy tale was a present. A present of thanks to a woman whose home had been very important to him," Askgaard said.
The Bunkeflod family then sent the manuscript to another family close to Andersen, the Plum family, in whose archives the story was found. A dedication written on the document later in blue ink reads: "To P Plum from his friend Bunkeflod."
Experts believe that the neatly written document is likely the copy of an original manuscript that has since been lost.
The story is about a neglected and dirty tallow candle which finds happiness when a tinder box sees its inner beauty and lights its wick.
"The Tallow Candle had found its right place in life – and shown that it was a real candle, and went on to shine for many a year, pleasing itself and the other creations around it," Andersen wrote.
Although the tale is not at the level of Andersen’s later works, it is the most important find since the 1920s, when the writer's memoirs were discovered at the Royal Library.
"This is a sensational discovery. Partly because it must be seen as Andersen’s first fairy tale, and partly because it shows that he was interested in the fairy tale as a young man, before his authorship began,"Askgaard said.
Read more at Discovery News
Scott and his team camped on the slopes of Mount Erebus, the southernmost volcano, during their journey. The spot was known as "the highest camp," according to a National Science Foundation release.
Clive Oppenheimer, a volcanologist at Cambridge University in England and working at Erebus as part of an NSF team, found what he thinks is the same camp site using written accounts and historic images from the Scott Polar Research Institute in Great Britain, the NSF release said. (The institute was founded by one of the men from Scott's party who climbed Erebus as part of the 1912 Terra Nova expedition.)
The site Oppenheimer located features a ring of stones where a tent once stood and appears to match historic photos taken during the 1912 expedition. "Conservators from the New Zealand-based Antarctic Heritage Trust have been asked to verify the historic find," the NSF wrote.
The area will be recorded and searched to look for artifacts from the original expedition. Tents and other sites from early 20th century expeditions have also been found and preserved, some with a wealth of artifacts.
The team that climbed Mount Erebus in 1912 included geologist Raymond Priestley; they took geological specimens and mapped the area. Scott's expedition was more focused on gleaning scientific research from their mission than Amundsen's was.
The 1912 expedition was preceded at Erebus by the 1907-1909 Nimrod Expedition, mounted by explorer Ernest Shackleton, which failed to reach the South Pole.
Read more at Discovery News
Dec 13, 2012
The scrappy organisms also outnumber plants 17 to 1, the study, published in the latest journal Science, suggests.
"There are different reasons to explain this," project leader Yves Basset told Discovery News. "They are small and can make a living out of nearly everything, including other arthropods, decomposing matter, plant tissues, etc."
Basset also pointed out that often bug larvae don't compete with adults since they feed on different foos resources.
Basset is scientific coordinator of the CTFS Arthropod Initiative at the Smithsonian Tropical Research Institute. To better understand arthropod diversity, he and 102 other researchers looked for the organisms in the San Lorenzo forest reserve of Panama.
Bugs tend to thrive in tropical rainforests, but the population at this particular reserve in Panama is thought to be average. The scientists chose to work there because the Smithsonian has a canopy crane and other devices at the site that facilitate access to everything from the canopy forest to the substrate below.
By scaling up the diversity values obtained from twelve other intensively sampled areas, the team calculated that the 23.2-square-mile rainforest reserve harbors an excess of 25,000 arthropod species. These calculations, in turn, contributed to the estimated ratios comparing numbers of arachnids to plants and mammals.
Basset thinks that these ratios hold true for cities as well, and may even skew higher in favor of arthropods at urban settings.
"The mammal fauna in cities is rather depleted, but not necessarily that of arthropods," he explained. "For example, a small urban park may not host many mammal species, because it may be a too small area to sustain species requirements, such as food and living space. However, let's say you have 10 species of trees in this park, then they may well support as many as 200 arthropod species, according to our data."
Humans tend to view insects mostly as being detrimental. They can at times spread disease and destroy crops.
"But we forget that these represent only a few species in comparison to the whole of arthropod biodiversity," Basset said. "The majority of insects live in forests and are responsible for the maintenance of these forests via the different services of pollination, decomposition and herbivory. In addition, many arthropods are efficient predators or parasites that suppress the levels of herbivores."
Outbreaks of pests do not exist in tropical forests, he pointed out, suggesting that arthropods help to keep ecosystems in balance.
These organisms additionally "represent a formidable, but untapped, reserve of DNA, genes and molecules -- again about 20 times more species-rich than plants from which we nevertheless get most of our medications," he continued. "Who knows what may be concealed in these arthropod molecules and how we could use them? We also need to discover most of these species/molecules before they disappear from Earth."
This latest study and others indicate that we may be sharing the planet with about 6 million arthropod species. Out of these, we only know about 1 million, with the rest and many others possibly threatened by pollution, habitat loss, and other human-related problems.
Read more at Discovery News
"The first time I saw it, I about fell over,” said Ritchie Garrison, professor of history professor and director of the Winterthur Program in American Material Culture at the University of Delaware. "It was a bit like walking into the past."
The discovery was entirely accidental. Garrison and Michael Burrey were in the process of revamping Garrison's 19th century house in Plymouth, Mass. Burrey was also working on a project at a local preschool in Duxbury, Mass., where he discovered what turns out to be a 18th century joiner's shop. Garrison invited several experts in material culture got to see the shop for themselves.
"I said 'holy cow!'" recalled Garrison, of his first look. If the date painted on the building is accurate the shop could trace back to at least 1789. Eighteenth century shops are extremely rare, unlike the more common 19th-century shops, said Garrison.
The shop provided all sorts of clues to its uses and even the local ecology 200 years ago. And although the school used the shed, many of the features of the shop are essentially untouched. The original workbenches, for instance, are still intact and in good condition. Those benches show different kinds of uses and even the woods they were made of contain clues about the local forests in the 1700s. There was also a conspicuously removed fireplace.
As for the wood itself, dendrochronology shows that it's from the second or third generation of trees replanted after original New England settlement by Europeans.
According to local records, the workshop belonged to a master carpenter named Luther Sampson, according to Garrison.
Read more at Discovery News
The creature -- related to crabs, lobsters and shrimp -- is an ostracod, or a type of crustacean sometimes known as seed shrimp. It represents a new species, Pauline avibella, in memory of the late wife of David Siveter, who led the research project.
The 0.4-inch-long animal was found, not only with its shell, but also with its soft parts -- body, limbs, eyes, gills and digestive system. Such well-preserved remains from that ultra prehistoric period are near unheard of in the fossil record.
The discovery of the tiny shelled animal was made in Herefordshire, Welsh Borderland. The rocks at the site date to a time when southern Britain was a sea area on a small continent situated in warm, southerly subtropical latitudes. The ostracods and associated marine animals living there were covered by a fall of volcanic ash that preserved them frozen in time.
"Ostracods are the most abundant fossil arthropods, occurring ubiquitously as bivalved shells in rocks of the last 490 million years, and are common in most water environments today," Siveter said. "The find is important because it is one of only a handful preserving the fossilized soft-tissues of ostracods."
He continued, "The preservation of soft-parts of animals is a very rare occurrence in the fossil record and allows unparalleled insight into the ancient biology, community structure and evolution of animals - key facts that that would otherwise be lost to science."
As the image here shows, the fossils were reconstructed virtually, by using a technique that involves grinding each specimen down, layer by layer, and then photographing it at each stage. It took 500 such "slices" to create the image.
Read more at Discovery News
Remember the Hubble Ultra Deep Field? The deep, mind blowing, time-traveling expanse of galaxies that reminds us of how truly itty-bitty we all are? Well, it still keeps providing astronomers with new objects of study with more observations.
The new observing campaign with Wide Field Camera 3 on Hubble finished up last September. The goal was to find more galaxies in the redshift range of 8.5 to 10, a crucial but understudied time in galaxy formation. In more tangible numbers, according to my favorite cosmology calculator, that is when the Universe was about 500 million years old, a mere fraction of its current 13.75 billion years.
Just stop for a moment and process that this camera detected photons from over 13 BILLION light years away. Yes, that's really far.
This is a time in the universe when the very first galaxies were forming. Little is known about this epoch, but our telescopes and techniques getting better and better, allowing us to probe this period of creation a little more every year. When the James Webb Space Telescope* (JWST) launches, it will further open up these proto-galaxies to our explorations with a large mirror deployed away from the distorting effects of the Earth's atmosphere and with sensitivity to infrared light. Since these baby galaxies are so heavily redshifted by the expansion of the universe over such great distances, infrared is the best way to study them.
In this new image (top), seven such distant galaxies were identified, including one that had tentatively been announced with a redshift of 10.3 and now has a tentative redshift of 11.9, making it the new record-holder, pending confirmation. Though seven is not a large sample by any means, it at least allows us to put the first data points on a plot describing this sample. It appears as though, when you go further back in time to this epoch, that the brightness and star formation rate of these galaxies drop off a bit, as if this were just a period of "ramping up" before the fireworks really began.
These galaxies would have been emitting ultraviolet light that ionized the hydrogen gas that pervaded the Universe at this early time. That means the ultraviolet photons would cause the electron to be stripped from a hydrogen atom. Much effort has been put into detecting this neutral hydrogen and studying its ionization with low frequency radio telescopes.
Read more at Discovery News
Dec 12, 2012
The new discovery offers the earliest evidence yet of cheese-making, which began before people developed the ability to digest the lactose sugars in unprocessed milk.
Not only did cheese, which contains very little lactose, provide a valuable source of nutrition for prehistoric Europeans. It also allowed them to store milk in a form that was easy to transport and would keep for months without spoiling.
"The interesting thing is that people at that stage could not digest the lactose in the milk, so processing milk into cheese would have given them the benefit from the nutritious effects of milk without having the side-effect of being ill," said Mélanie Salque, a chemist at the University of Bristol in the United Kingdom.
"It was a very good product for them because you don't have to kill animals to get the milk out of them," she added. "Milk was a big development and cheese was as well."
Some 30 years ago, archaeologists described sieve-like pottery fragments found in a region of north-central Poland, where some of the region's earliest farmers settled. The shards dated back to between 7,200 and 6,800 years ago. And the holes in the sieves were tiny, just two or three millimeters (about a tenth of an inch) wide.
Alongside the clay fragments were lots of cattle bones, leading some scientists to speculate that the reconstructed bowl-shaped containers were cheese-strainers. But without proof, other hypotheses have endured, including the possibility that the vessels were used to strain chaff while making beer.
In an attempt to figure out once and for all what the containers were for, Salque and colleagues conducted detailed chemical analyses on 50 fragments from 34 vessels. They were looking specifically for residues of fats, which get absorbed by pores in clay during food processing and can remain trapped for millennia.
After crushing a small amount of each fragment into a powder, mixing the powder with solvents, and running the solution through their instruments, the researchers detected milk residues in all but one of the pieces.
People wouldn't have strained milk before drinking it, and butter is not processed that way. The only possible explanation for what they found, the team reports today in the journal Nature, is that people were coagulating milk and then using the sieves to separate semi-solid curds from liquid whey to make cheese.
"They have these vessels that look like they could be strainers for making cheese, but what they've really done now is confirmed that that's the case," said Mark Thomas, an evolutionary geneticist at University College London.
Read more at Discovery News
The discovery marks the largest grouping of early cauldrons ever found in Europe. One cauldron features a handle plate in the form of a cow's head; zoomorphic decoration is otherwise unknown on a British cauldron.
"Analysis of the interiors of the cauldrons has even revealed traces of animal fats, a tantalizing suggestion that these objects might have been used in cooking and serving meat-rich stews at Iron-Age feasts over 2,000 ago," Julia Farley, curator of European Iron Age collections at the British Museum, told Discovery News.
Farley's colleague Jody Joy, as well as Alexandra Baldwin and Jamie Hood from the museum, are still studying the artifacts, which were found buried in a 6.6-feet-wide pit. The cauldrons were made from iron and copper alloy in the second or first century B.C.
Each was built to last, with an iron rim and band supporting circular suspension handles. The main body of the cauldrons consisted of a central band and bowl of sheet copper alloy riveted together. "The iron rim and handles gave strength and rigidity, while the copper-alloy bowl acted as an excellent heat conductor," the researchers note.
When the cauldrons were buried, nearby Barbury Castle still might have been occupied. Another hill fort, Liddington Castle, likely had been abandoned. Nevertheless, given the possible fort protection and open space, "Chiseldon looks to be an ideal meeting place," the researchers believe.
What the cauldrons were last used for is a bit of a mystery, but Joy and team suspect "large quantities of food and drink were probably consumed." Feasts at the time "would have marked significant events in the calendar or special occasions, such as marriages."
Beef was the star attraction at the last big feast involving the cauldrons, the evidence suggests. The two cattle skulls, cow cauldron decoration and traces of animal fats all theoretically point to beef.
But the experts say it's too soon to make that conclusion.
Archaeologist Mike Pitts, who also edits British Archaeology, told Discovery News that "notwithstanding the cattle skulls, it might well have been pork. Pigs were important animals in feasting. Of course, whatever was in the cauldrons was boiled."
Read more at Discovery News
The study, published today (Dec. 12) in the journal Nature, suggests that ancient fossilized creatures found in Southern Australian sediments actually came from land, not from the ocean. If the findings are true, the fossils would have been lichenlike plants that first colonized land, not ocean-dwelling ancestors of jellyfish.
"We have big organisms living on land a lot further back than we thought before," said study author Gregory Retallack, a geologist and paleobotanist at the University of Oregon.
But the study has faced intense skepticism from several experts in the field -- some of whom have questioned not only the study's scientific validity, but also its acceptance into a prestigious scientific journal.
"I find Retallack's observations dubious, and his arguments poor. That this was published by Nature is beyond my understanding," wrote Martin Brasier, a paleobiologist at the University of Oxford who was not involved in the study, in an email.
Primitive sea dwellers
Scientists first discovered the fossils in 1947 in the Ediacaran Hills of Southern Australia. The reddish rocks contained imprints from a strange, striated creature called Dickinsonia, as well as other primeval creatures that lived around 550 million years ago.
Until now, scientists had long believed the rocks were made up of ocean sediments and that Dickinsonia and other primeval creatures fossilized in the outcroppings were sea dwellers similar to jellyfish or sea pens that lived just before the Cambrian explosion began about 540 million years ago, when all the major animal groups suddenly appeared.
But when Retallack first saw the fossils, he wondered whether they were formed on land. In particular, the fossils had a reddish hue that comes from oxygen in the atmosphere reacting with iron to create rust -- a process that doesn't happen under the sea, he said. He also noticed that nodules throughout the rock looked strikingly similar to the rootlike structures put out by primitive lichen or fungi found in other ancient soils.
To see if some of the Ediacaran fossils were land-dwellers, he tested the rock's composition and found it was characteristic of the very first stages of soil formation on land, in which nutrients such as potassium and magnesium are depleted. A similar process doesn't happen in the ocean, he said.
In the current paper, Retallack argues that the ancient fossils are actually a primitive precursor to lichen or fungi and that they helped colonize land, paving the way for the Cambrian explosion.
Even today, lichen are the pioneers that first take root on bare rock, creating the precursors of soil (other organisms can grow on lichens).
"One of the first things that happens when you have a piece of bare ground is some lichen come in and eventually some new stuff comes in like dandelions, and pretty soon you've got a tall Douglas fir forest," Retallack told LiveScience.
But several scientists have called his claims into question and wonder why Nature published the piece.
The rocks may have turned their reddish hue much more recently, some 65 million years ago, when they somehow rose above the water; in that scenario, the sediments could have been underwater at the time Dickinsonia and other Ediacaran creatures lived, Shuhai Xiao, a paleontologist at Virginia Tech wrote in an accompanying article in Nature. In addition, the chemical composition of the rocks doesn't preclude the fossils originating in the ocean.
Read more at Discovery News
Splash-cup plants, which live everywhere from jungles to deserts, have conical flowers that catch raindrops and use the resulting splash to encapsulate and launch seeds.
For example, the "splash cups" of Chrysosplenium echinus can use rain to spread seeds more than 3 feet (1 meter) away, a distance equal to 10 times the plant's height. That would be comparable to raindrops getting deflected 50 to 60 feet (15 to 18 m) away after falling on the average person.
To learn more about how these splash cups accomplish this trick, researchers analyzed high-speed video of droplets falling on both real flowers and plastic copies of the flowers with varying shapes. They generated artificial rain using a syringe that dripped water drops 4 millimeters wide, about as big as large natural raindrops.
The researchers saw the splash cups redirect incoming raindrops at up to five times their incoming speed. This means droplets falling at terminal velocity -- about 18 miles per hour (29 kilometers per hour) -- could get launched at up to 90 mph (144 kph).
The shape of the flowers helps explain why they can splash drops so far. The inclination of each flower's walls helps maximize the speed at which droplets travel after the splash, and the curvature of the cone creates a spout-like effect that concentrates the splash in one direction.
"This spout effect creates a jet of water that entrains the seeds and carries them away from the mother plant," researcher Guillermo Amador, a fluids researcher at the Georgia Institute of Technology in Atlanta, told LiveScience.
Past research suggests these plants evolved from species that originally used wind for seed dispersal, Amador said. They may have had to resort to a different strategy relying on raindrops, due to their short statures limiting the amount of wind they could catch and all the obstructions they might face close to the ground.
Read more at Discovery News
Dec 11, 2012
The new finding was only true for African-Americans, suggesting that the study hit on a particularly resilient group of people who thrived despite extreme childhood adversity. Even so, the study offers insight into how the experiences we have at very young ages can affect our health much later in life.
"We know that the social experiences of African-Americans and Caucasians in this country have been very different, at least for people over age 65," said Lisa Barnes, a cognitive neuropsychologist at Rush University Medical Center in Chicago. "We wanted to measure that and see if it had any effect at all."
In an effort to add to a growing interest in the long-term health influence of childhood adversity, Barnes and colleagues started by interviewing about 6,100 people who lived in Chicago and were enrolled in a study of Alzheimer's. All participants were at least 65 years old when the study began. The average starting age was 75.
In the first interview, seniors answered questions about their childhoods, including details about health, the financial situations of their families and how often someone read books to them. They also took a cognitive exam that included tests of memory.
The study began in 1993. Since then, the researchers have re-interviewed and tested participants every three years. The new study considered up to 16-years of data on some people.
Adults who were raised in the poorest homes scored the worst on their initial cognitive tests, and as expected with age, mental sharpness dropped as people aged.
But among African-Americans, rates of decline were slowest in people who remembered being hungry "sometimes," "often" or "always" as kids and who were thinner than average as older adults, the researchers report today in the journal Neurology. Childhood hunger and body size didn't make a cognitive difference in Caucasians.
"We expected it to come out the other way, that childhood adversity would be related to a faster rate of decline," Barnes said. "We actually found it was protective."
It's possible that calorie-restriction early in life helped cushion the brain from later aging, in line with research that has linked eating less with longer lifespans. But Barnes suspects that non-biological explanations are more likely.
Very few white people in the study reported extreme adversity as children, for one thing, possibly making the sample size too small to detect any relationships in that group.
As for the African-Americans, those who were still alive in their 60s, 70s, 80s and beyond likely represent the hardiest members of a population that came of age before the civil rights movement when there were few opportunities available to them.
"One of the things we know is that African-Americans live sicker and die younger than Whites," said Tené Lewis, a psychosocial epidemiologist at Emory University's Rollins School of Public Health in Atlanta. "When you get to age 65, which is the baseline in the new study, you're already dealing with a heartier African-American population. These are people who, no matter what you throw at them, are particularly resilient."
Read more at Discovery News
Completely hidden in the flat and featureless landscape, the labyrinth was identified after a five-year investigation into the arid Peruvian coastal plain land, about 250 miles south of Lima, where the mysterious geoglyphs are located.
"As you walk it, only the path stretching ahead of you is visible at any given point," Clive Ruggles of the University of Leicester's School of Archaeology and Ancient History, said.
Ruggles and colleague Nicholas Saunders of the University of Bristol's Department of Archaeology and Anthropology walked more than 900 miles of desert, tracing the lines and geometric figures carved between 100 B.C. and 700 A.D. by the Nasca people. They reported their findings in the December issue of the journal Antiquity.
Also known for their obsession over trophy heads –- they boasted the largest collection of human heads in the Andes region of South America -- the Nazca flourished in Peru between the first century B.C. and the fifth century A.D. and slid into oblivion by the time the Inca Empire rose to dominate the Andes.
The researchers studied the layers of superimposed designs, and the associated Nazca pottery, combining the experience gained by walking the lines with scientific data from satellite digital mapping.
"Factors beyond my control brought the 1984 expedition to an abrupt halt. It was only 20 years later that I eventually had the opportunity to return to Nazca, relocate the figure and study it fully," Ruggles said.
He added that the only way to become aware of the labyrinth is to walk its 2.7-mile length through a disorienting twisting path.
Indeed, the labyrinth features 15 corners that would bring the walker away from and towards a large hill before turning into a spiral passageway. Walking the entire path would have probably taken about an hour.
"I was almost certainly the first person to have recognized it for what it was," Ruggles said.
The labyrinth's well-preserved edges suggest it was walked by a few people in single line. Unfortunately, there is no way to know the meaning of the structure and how it was used.
According to the researchers, walking the lines has provided an important source of information to better understand the enigmatic desert drawings.
Recognizable only from the air, the lines, geometric designs and images of animals and birds, some up to 900 feet long, have been a source of mystery since their discovery nearly a century ago.
Called anything from ancient calendars to landing strips for alien spaceships, the lines were also linked to water deities, suggesting that they marked sacred paths and places where people went to worship.
After studying the integrity of many lines and figures within a 50-square-mile area, Ruggles and Saunders concluded that the meandering and well-worn trans-desert pathways were most likely created for functional purposes. On the contrary, the famous arrow-straight lines and geometric shapes appear to have had a spiritual and ritual purpose.
Read more at Discovery News
The worst offenders appear to be plastic fetching batons, called "bumpers," which are used to teach dogs how to retrieve.
"In the process of training a lab, you do a lot of work with these plastic bumpers," co-author Phil Smith was quoted as saying in a press release. "I have a lot of bumpers in my garage, and they spend a lot of time in the mouths of my retrievers. Well, lots of attention has been given to chemicals in plastics lately regarding their effects on humans. Since we all care about our dogs, and we want them to be as healthy and smart and well-behaved as possible, we decided to look into this."
Smith, who raises and trains Labrador retrievers, and hunts with them as well, is an associate professor of terrestrial ecotoxicology at The Institute of Environmental and Human Health at Texas Tech University. He worked on the study with colleague Kimberly Wooten.
Smith and Wooten suspected that bumpers, and other dog toys, could leach phthalates and bisphenol A (BPA) into the mouths and bodies of dogs. The chemicals are used to give elasticity to plastic and vinyl and are known endocrine disruptors that mimic estrogen or act as anti-androgens. Studies indicate they could lead to negative health effects.
To test for the chemicals, the researchers created simulated dog saliva, then simulated chewing by squeezing purchased bumpers and dog toys with stainless steel salad tongs. Some bumpers and toys were also weathered outside to determine if older toys gave off more chemicals.
"We found that the aging or weathering the toys increased concentrations of BPA and phthalates," Smith said. "The toys had lower concentrations of phthalates than the bumpers, so that’s good news. But they also had some other chemicals that mimicked estrogen. We need to find out what those are."
Wooten explained that BPA and phthalates can have effects on developing fetuses and can have a lifelong effect on offspring of lab animals. Studies on humans have resulted in mixed conclusions, but concern was enough to warrant the U.S. government banning the use of BPA in baby bottles this year.
Questions still remain about how much of these chemicals actually leach into a dog's mouth during play.
Read more at Discovery News
In the past, researchers believed that the K-T extinction, which occurred around 65 million years ago, wiped out dinosaurs, but mostly spared lizards and snakes. But the new findings, published today (Dec. 10) in the Proceedings of the National Academy of Sciences, showed that about 83 percent of these reptiles went extinct.
"I think it is a pretty important piece of work," said Stephen Brusatte, a paleontologist from Columbia University who was not involved in the study. "It does a nice job of showing that extinction at the end of the Cretaceous really hit lizards and snakes hard."
The findings actually make the story of the end Cretaceous Era mass die-off more consistent, because it's hard to imagine a catastrophe capable of destroying the dinosaurs would spare lizards and snakes, said study co-author Nicholas Longrich, a paleontologist at Yale University.
"You can't wipe out the dominant carnivores and dominant herbivores on the planet without causing devastation of the ecosystem on a massive scale," Longrich told LiveScience.
Most researchers think a giant meteor crashing to Earth at the Yucatan peninsula caused the mass extinction that killed the dinosaurs. The impact likely released a sun-blocking cloud of dust into the atmosphere, preventing plants from making food and causing dinosaurs to die as a result.
To see if lizards and snakes were somehow shielded from the doom, Longrich and his colleagues collected fossil records from the reptiles across North America. Before the extinction, snakes and lizards were flourishing, with 27 lizard species and three snake species documented in the fossil record. In the years immediately afterward, only five species remained, with most disappearing from the fossil record quite abruptly, Longrich said.
If most plants died, then plant eaters and their predators would have died off too, he added. It's likely that only scavengers and animals that preyed on them came out of the Cretaceous period relatively unscathed.
"When everything starts dropping dead, and everything dies, there's probably bugs and grubs and worms eating them and that's probably what the survivors were eating," Longrich said.
The findings are consistent with an asteroid slamming into Earth and leading to the dino demise, Longrich said. (Just last week at the meeting of the American Geophysical Union, researchers presented an argument for volcanoes, not a space rock, doing in the dinosaurs.)
The new fossil analysis convincingly shows that reptiles faced a severe extinction in North America, wrote Richard Cowen, a geoscientist at the University of California, Davis, who was not involved in the study, in an email. Because the meteorite hit Chicxulub in Mexico, you would expect the greatest death toll within North America, but the researchers' case for a worldwide die-off from the space rock is much shakier, he said.
Read more at Discovery News
Dec 10, 2012
The research, reported by a team of Canadian and U.S. scientists in Nature Geoscience, provides new insight into how ancient metal-ore deposits can be used to better understand the chemistry of the ancient oceans -- and the early evolution of life.
Sulfate is the second most abundant dissolved ion in the oceans today. It comes from the "rusting" of rocks by atmospheric oxygen, which creates sulfate through chemical reactions with pyrite, the iron sulfide material known as "fool's gold."
The researchers, led by PhD student John Jamieson of the University of Ottawa and Prof. Boswell Wing of McGill, measured the "weight" of sulfur in samples of massive sulfide ore from the Kidd Creek copper-zinc mine in Timmins, Ontario, using a highly sensitive instrument known as a mass spectrometer. The weight is determined by the different amounts of isotopes of sulfur in a sample, and the abundance of different isotopes indicates how much seawater sulfate was incorporated into the massive sulfide ore that formed at the bottom of ancient oceans. That ancient ore is now found on Earth's surface, and is particularly common in the Canadian shield.
The scientists found that much less sulfate was incorporated into the 2.7 billion-year-old ore at Kidd Creek than is incorporated into similar ore forming at the bottom of oceans today. From these measurements, the researchers were able to model how much sulfate must have been present in the ancient seawater. Their conclusion: sulfate levels were about 350 times lower than in today's ocean. Though they were extremely low, sulfate levels in the ancient ocean still supported an active global population of microbes that use sulfate to gain energy from organic carbon.
"The sulfide ore deposits that we looked at are widespread on Earth, with Canada and Quebec holding the majority of them," says Wing, an associate professor in McGill's Department of Earth and Planetary Science. "We now have a tool for probing when and where these microbes actually came into global prominence."
"Deep within a copper-zinc mine in northern Ontario that was once a volcanically active ancient seafloor may not be the most intuitive place one would think to look for clues into the conditions in which the earliest microbes thrived over 2.7 billion years ago," Jamieson adds. "However, our increasing understanding of these ancient environments and our abilities to analyze samples to a very high precision has opened the door to further our understanding of the conditions under which life evolved."
Read more at Science Daily
Hailed by Secretary-General Ban Ki-moon as a major step forward in protecting women and girls and ending impunity for the harmful practice, the text is expected to be endorsed by the UN general assembly this month.
How did the practice begin anyway?
Although theories on the origins of FGM abound, no one really knows when, how or why it started.
"There's no way of knowing the origins of FGM, it appears in many different cultures, from Australian aboriginal tribes to different African societies," medical historian David Gollaher, president and CEO of the California Healthcare Institute (CHI), and the author of "Circumcision," told Discovery News.
Used to control women's sexuality, the practice involves the partial or total removal of external genitalia. In its severest form, called infibulation, the vaginal opening is also sewn up, leaving only a small hole for the release of urine and menstrual blood.
While the term infibulation has its roots in ancient Rome, where female slaves had fibulae (broochs) pierced through their labia to prevent them from getting pregnant, a widespread assumption places the origins of female genital cutting in pharaonic Egypt. This would be supported by the contemporary term "pharaonic circumcision."
The definition, however, might be misleading. While there's evidence of male circumcision in Old Kingdom Egypt, there is none for female.
"This was not common practice in ancient Egypt. There is no physical evidence in mummies, neither there is anything in the art or literature. It probably originated in sub-saharan Africa, and was adopted here later on," Salima Ikram, professor of Egyptology at the American University in Cairo, told Discovery News.
Historically, the first mention of male and female circumcision appears in the writings by the Greek geographer Strabo, who visited Egypt around 25 B.C.
"One of the customs most zealously observed among the Egyptians is this, that they rear every child that is born, and circumcise the males, and excise the females," Strabo wrote in his 17-volume work Geographica.
A Greek papyrus dated 163 B.C. mentioned the operation being performed on girls in Memphis, Egypt, at the age when they received their dowries, supporting theories that FGM originated as a form of initiation of young women.
Other writers later explained that the procedure was carried for less ritualistic reasons.
According to the 6th century A.D. Greek physician Aetios, the cutting was necessary in the presence of an overly large clitoris.
Seen as "a deformity and a source of shame," the clitoris would produce irritation for its "continual rubbing against the clothes" thus "stimulating the appetite for sexual intercourse."
"On this account, it seemed proper to the Egyptians to remove it before it became greatly enlarged, especially at that time when the girls were about to be married," Aetios wrote in The Gynecology and Obstetrics of the Sixth Century A.D.
According to U.S. historian Mary Knight, author of the paper "Curing Cut or Ritual Mutilation?: Some Remarks on the Practice of Female and Male Circumcision in Graeco-Roman Egypt," medical motivations probably mixed with ritual, social and moral reasons to favor "the continuation of a practice that initially may have been narrowly performed and whose original motivation most likely had long been forgotten."
Many centuries later, 19th century gynaecologists in England and the United States would perform clitoridectomies to treat various psychological symptom as well as "masturbation and nymphomania."
"The surgeries we see in Victorian England and America were generally based on a now discarded theory called 'reflex neurosis,' held that many disorders like depression and neurasthenia originated in genital inflammation," Gollaher said.
"The same theory was behind the medicalization of male circumcision in the late 19th century," he added.
It is only relatively recently that FGM has been recognized internationally as a violation of the human rights of girls and women.
Sweden was the first Western country to outlaw FGM, followed in 1985 by the UK. In the United States it became illegal in 1997, and in the same year the WHO issued a joint statement with the United Nations Children’s Fund (UNICEF) and the United Nations Population Fund (UNFPA) against the practice. FGM is a crime in many countries now.
Last week the head of the Organization of Islamic Cooperation also called for abolishing female genital mutilation.
"This practice is a ritual that has survived over centuries and must be stopped as Islam does not support it,"Secretary-General Ekmeleddin Ihsanoglu said at the intergovernmental organisation's 4th conference on the role of women in development, in Jakarta, Indonesia.
An estimated 140 million girls and women now alive have undergone the mutilating procedure in 28 African countries, as well as in Yemen, Iraq, Malaysia, Indonesia and among certain ethnic groups in South America and some immigrant communities in the West.
Read more at Discovery News
For the first time, scientists have figured out how those barbs work together to make it is so easy for quills to penetrate tissue but so hard to pull them out.
The discovery could inspire a slew of useful medical devices, including needles that hurt less going in or adhesive patches that would prevent gut leakage after gastric bypass surgeries and related procedures. Already, the researchers have created model quills that work like their natural counterparts.
"We're constantly looking to nature for examples that can inspire new approaches toward solving medical problems," said Jeffrey Karp, a bioengineer at Brigham and Women’s Hospital in Cambridge, Mass. "I really think evolution is the best problem-solver."
Porcupines are slow-moving creatures that lack the speed to run away from predators. Instead, defense comes in the form of some 30,000 quills that cover the back of each animal. And it doesn’t take much pressure for the quills to leave a porcupine’s body and enter the tissue of its attacker.
Scientists have long known that North American porcupine quills have barbs on their ends that make post-attack removal difficult and painful. To better understand how the quills pack their punch, Karp and colleagues inserted gently removed quills into a variety of targets, including chicken muscles, pig skin and synthetic human skin.
Using a mechanical tester, the researchers found that it took much less force than expected for the quills to penetrate tissues and more force than expected to pull them out, the team reports today in the Proceedings of the National Academy of Sciences.
The barbs, which cover just the last four millimeters (0.2 inches) of each quill’s tip, proved to be essential. When the researchers painstakingly removed barbs from quills, tests showed that it took more force for penetration to occur and less force for ejection.
Removing just some of the barbs showed that the hooks at the very last millimeter of the tip were most important for stickiness. But all of the barbs seem to work cooperatively.
As a last step, the researchers used plastic to mold model quills, which behaved just like the porcupine-made versions. That opens the way to developing medical applications. By isolating the ease with which quills penetrate skin and muscle, for example, scientists could develop porcupine-inspired needles that cause less pain.
The team also used their synthetic quills to create a barbed patch, which stuck well to tissues. Compared with a barbless-patch, it required 30 times more force to remove.
Read more at Discovery News
Called viviparity, this form of birth is used by humans, but clearly we were far from being the first to evolve it.
The study, published in the December issue of Historical Biology: An International Journal of Paleobiology, focuses on mesosaurs, which were among the world's first aquatic reptiles. They lived in what are now South America and South Africa at a time when these two landmasses were united and part of the giant supercontinent Pangaea.
Mesosaurs, and even their earlier ancestors, possibly "were not able to produce hard shelled eggs, at least for the first several million years of their evolution," lead author Graciela Piñeiro, a paleontologist at Uruguay's Facultad de Ciencias, told Discovery News. "After the recent discovery of mesosaur embryos, we can state with a high degree of confidence that embryo retention developed early in amniote evolution, given that mesosaurs are among the basal-most reptiles and that they date from the Early Permian around 280 million years ago."
Piñeiro and colleagues Jorge Ferigolo, Melitta Meneghel and Michel Laurin recently discovered the exceptionally well-preserved mesosaur embryos at sites in Uruguay and Brazil. The environmental conditions at the locations allowed for the preservation of soft tissues, nerves and blood vessels, she said.
Giving birth in this manner and laying eggs each come with advantages and disadvantages. Eggs with hard, mineralized shells, such as those associated with today's chicken eggs or those of dinosaurs, are believed to help reproduction on dry land. But many terrestrial animals, including humans, do not lay eggs, so there must be other benefits to viviparity.
"We think that the retention of the eggs may have appeared in amniotes as a useful strategy to avoid predation and increase survivorship chances for the embryos," Piñeiro said.
Parental care often then follows. There is even some evidence that mesosaurs provided such care, because adults and juveniles have been associated together in the fossil record.
At least some mesosaurs even had the added challenge of giving birth and raising young in extremely salty water.
"In Uruguay, mesosaurs may have first colonized the shallow water environment of the Mangrullo Formation, which under the establishment of arid climatic conditions that increased evaporation became like a salty marsh where just a few opportunistic organisms could tolerate the anoxic bottom conditions generated by the accumulation of high amounts of organic matter," Piñeiro explained.
When infant mesosaurs entered the world, they possibly even had a salt gland and other anatomical adaptations already in place, allowing them to survive the otherwise challenging conditions.
There is also compelling evidence that giant, carnivorous, four-flippered reptiles known as plesiosaurs gave birth to live young as well. Robin O'Keefe of Marshall University and team discovered a big embryonic marine reptile contained in the fossil of its 15.4-foot-long mother, which lived 78 million years ago.
"The embryo is very large in comparison to the mother," O'Keefe said, "much larger than one would expect in comparison with other reptiles. Many of the animals alive today that give birth to large, single young are social and have maternal care. We speculate that plesiosaurs may have exhibited similar behaviors, making their social lives more similar to those of modern dolphins than other reptiles."
There is one disturbing side-note to such prehistoric pothering: cannibalism.
Read more at Discovery News
Dec 9, 2012
According to the Hollywood Reporter,
On Wednesday, one of the most entertaining lawsuits of the year was filed in Illinois federal court. It comes from Dr. Jaime Awe, director of the Institute of Archeology of Belize. This real-life Indiana Jones is suing on behalf of the nation of Belize over the Crystal Skull artifact, popularized in the 2008 Steven Spielberg film "Indiana Jones and the Kingdom of the Crystal Skull," Awe is demanding the return of the Crystal Skull from a treasure-hunting family that allegedly stole it 88 years ago from Belize.
Awe is suing Lucasfilm, the Walt Disney Company, and Paramount Pictures. Awe states that the crystal skull described in the film was stolen by a British explorer (and sometime archaeologist) named F.A. Mitchell-Hedges during a visit to the Maya ruins of Lubantuun in the jungle of Belize in the early 1920s.
His adopted daughter Anna Mitchell-Hedges is said to have discovered the skull while exploring the ruins. They returned to England with the skull, and Anna regularly exhibited the skull after her father's death in 1959.
In his complaint Awe cites a 1928 "Antiquities Ordinance" which prohibited the removal of artifacts from Belize without express government permission. Since the crystal skull was illegally removed from the ruins and used as a basis for the most recent Indiana Jones film, Awe and Belize want a cut of the profits and the return of the stolen skull which they see as part of their cultural heritage.
"Lucasfilm never sought, nor was given permission to utilize the Mitchell-Hedges Skull or its likeness in the Film," says the complaint. "To date, Belize has not participated in any of the profits derived from the sale of the Film or the rights thereto."
The True Story of the Crystal Skull
It's unlikely that the lawsuit will go anywhere -- mostly because (apparently unbeknownst to Awe) it's based on a famous hoax. Daniel Loxton, editor of Junior Skeptic magazine, researched the history of the skull and discovered that Anna Mitchell-Hedges changed her story about how she got the skull at least twice.
The first account stated that she and her father found the skull together beneath an altar in a ruined temple in 1926. In a 1983 account she claimed she was with a worker who was felling trees in the jungle and saw something shiny beneath the stones and dug it up on the spot. Then she claimed she found it after being lowered into a hidden temple with ropes (ironically, in a scene reminiscent of an Indiana Jones film). Furthermore there's no evidence that Anna even visited the ruins at Lubantuun where she claims to have found the skull.
The truth is that neither Anna nor her father found the skull, amid the Lubantuun ruins, on eBay, or anywhere else.
The historical record shows that Mr. Mitchell-Hedges bought the skull from an antiquities collector named Sydney Burney in 1933, which he later sold to pay a debt. It was later purchased by his daughter Anna, who made up an adventurous story about finding it on her 17th birthday in the jungle ruins of a lost city.
All the fanciful, adventurous stories about discovering the crystal skull amid ruins in the Central American jungles were just myths created to craft a colorful backstory to the strange skull. "I discovered it in a long-lost ruined jungle temple" is more fun than "My father bought it from a guy at an auction."
The hoax lasted for decades, and fooled hundreds of crystal skull enthusiasts. Since the Mitchell-Hedges skull was never even in Belize -- much less found there in an ancient Maya ruin by an adventurer's teenage daughter -- the Belizean government has no claim over it. It's all a myth.
Read more at Discovery News
The region is known for its sunny weather, so it definitely was not a white Christmas.
"It was not a very festive celebration either," Rachel Porter, special programs coordinator for the Florida Department of State, told Discovery News. "There were no Christmas trees or presents. Instead, it was a religious observance with a Christmas mass."
Spanish explorer and conquistador Hernando de Soto established his winter encampment site of 1539-40 near what is now the Historic Capitol in downtown Tallahassee. He, along with other members of his expedition, celebrated the first U.S. Christmas.
Porter, who is also an archaeologist that helped to excavate the Florida site, said a written chronicle from the 16th century sheds light on what took place there.
Eight months before Christmas, in May 1539, de Soto landed nine ships with over 620 men and 220 horses at present-day Shaw's Point in Bradenton. De Soto named it Espíritu Santo, meaning Holy Spirit. The ships brought priests, craftsmen, engineers, farmers, and merchants; some were with their families. Some came from Cuba, but most were from Europe and Africa. Few had traveled before outside of Spain.
Women from that group probably would have cooked the food served on Christmas Day. "During the excavations we found pig bones," Porter said. "The Spanish were the first to bring pigs to Florida."
Though pork was likely on the menu of the first Christmas celebrants in America, such meat was not plentiful, Porter adds, so the meal likely would have included plenty of local vegetables, fruits and seafood. Turkey might have been on the menu too.
In addition to pig bones, Porter said archaeologists digging at the site found "artifacts such as chain mail, from armor worn by soldiers, cross bow darts, coins and pottery." Most probably would have been put aside on Christmas Day. Music, however, might have been enjoyed after the service.
De Soto recruited guides from local Native American tribes during his U.S. travels. In the Tallahassee region, these came from the Apalachee tribe. The Apalachees are the original residents of northwestern Florida, but a war in the early 1700's nearly destroyed their population. Some fled to Alabama and Louisiana, where the remaining Apalachee people live to this day.
The Spaniards learned from the Apalachee, who knew how to live off the land. Basket weaving, for example, allowed them to construct useful containers out of local plant materials.
The most vivid architectural legacy of the de Soto settlement is Mission San Luis in Tallahassee. The first permanent buildings associated with the mission were erected in 1633. As a commemorative sign at the mission shares, the buildings housed descendants of the Native Americans whose village Hernando de Soto and his men appropriated.
For three generations, more than 1,500 Apalachee Indians and Spanish colonists lived together at Mission San Luis. It preceded missions in California by more than 150 years.
Mission San Luis includes a reconstructed Franciscan church, Spanish fort, living quarters, and a five-story Apalachee council house. Porter said the church was a challenge for the excavating archaeologists.
"The most challenging aspect of the excavation and reconstruction of the church was avoiding any damage to the cemetery located beneath the church's floor," she explained. "An estimated 900 mission residents are buried there."
While the first Christmas likely was celebrated outside, the mass would have been very similar to those held in the Franciscan chapel.
In 2013, Florida will celebrate this period during the state's 500th anniversary of Spain's arrival. As part of the "Viva Florida 500" commemorative events, on Jan. 5, Mission San Luis will host "First Christmas in La Florida."
Read more at Discovery News
The cocoon looks like those produced by living leeches, such as the medicinal leech Hirudo medicinalis. Encased inside was a bell animal that looked similar to species in the genus Vorticella; its body extends 25 microns (about the width of some human hairs) with a tightly coiled stalk about twice that long. And like all eurkaryotes, the organism was equipped with a nucleus -- in this case, a large horseshoe-shaped nucleus inside the main body. (A micron is one-millionth of a meter.)
This bell animal lived during the Late Triassic Period, when the Earth was much warmer, with dense rain forests flourishing along what is today the Transantarctic Mountain Range where it was found. At the time, Antarctica was part of the supercontinent Gondwana, though it was still located at high latitudes.
Past research has suggested this coiled stalk, which is used to attach to substrates, may be one of the fastest cellular engines known, changing from a telephone wire-like structure to a tight coil at a speed of about 8 centimeters (3.1 inches) per second -- the equivalent of a human being walking the across more than three football fields in one second.
Preserving soft tissue
Possibly even more amazing is the fact that this soft-bodied, microscopic creature survived the vagaries of time. Preserving a soft-bodied organism like this one for so long is tricky and requires some outside intervention to keep the tissues from degrading. In this case, rather than tree resin (called amber when hardened) that preserved dino DNA in the bellies of amber-trapped mosquitoes in "Jurassic Park," a mucous cocoon did the trick.
"This preservation is quite bizarre, but soft-bodied organisms cannot usually become fossilized unless they are rapidly entombed in a medium that prevents further decay," study researcher and paleobotanist Benjamin Bomfleur, of the Biodiversity Institute at the University of Kansas, told LiveScience.
Here's how the researchers think the hasty preservation took place: "A leech secreted a mucous cocoon that was deposited under water or in wet leaf litter, somewhere in a river system which lay in present-day Antarctica," Bomfleur said. This bell animal must have used its long, rapidly contracting stalk to attach itself to the cocoon soon after, becoming trapped and completely encased by the still-slimy cocoon, which hardened over hours to days.
"The cocoon with the such-enclosed bell animal then was deposited in mud that over time turned into the sedimentary layer where we found it some 200 million years later," Bomfleur explained.
The only other example of this type of preservation comes from a 125-million-year-old cocoon encasing a nematode worm and discovered in Svalbard.
Identifying the bizarre creature
When Bomfleur first noticed the tiny animal in samples he'd collected from Antarctica, he didn't know what he was looking at and didn't have time to consult with an expert in such microfossils, as he was working on his doctoral degree.
"Later this year, however, I finally found the time to look for someone with an expertise on freshwater microorganisms in order to get an expert opinion on the thing," Bomfleur said, adding he contacted Ojvind Moestrup of the University of Copenhagen.
Read more at Discovery News
Using the Gamma-Ray Burst Polarimeter (GAP) onboard the spacecraft, a team of Japanese scientists have made the most precise measurements of energetic gamma-ray burst photons to date.
"This result puts a fundamental constraint on quantum gravity, a dream theory reconciling Einstein's theory of relativity and quantum theory," Kenji Toma, of Osaka University, said in a statement.
A quantum universe
Gamma-ray bursts are exceptionally powerful explosions thought to result from violent events like star deaths and collisions of dense neutron stars. Toma and his team used detailed measurements of gamma-ray bursts to study the properties of the photons and determine their polarization, or how their electric fields are oriented in relation to the motion of the particles. The electric field of polarized light bounces up and down on an axis perpendicular to the direction the photons travel in.
"Most 3D projection systems in movie theaters project two versions of the movie at two different polarizations -- both at 45 degrees to the horizontal, but perpendicular to each other -- so that when you view the movie through appropriately polarized glasses, the left eye sees the version of the movie meant for the left eye, and the right eye sees the version meant for the right," astrophysicist Derek Fox of the University of Pennsylvania told SPACE.com by email. Fox was not part of the team behind these findings, but studies gamma-ray bursts like those observed in this case.
The findings could have implications for superstring theory -- the idea that all fundamental particles are actually loops of vibrating string -- which is one attempt to unify nature's forces and create a theory of everything. If the idea is right, it would help reconcile two contradictory theories: Einstein's general relativity, which describes things that are very big, like gravity, and quantum mechanics, which describes the realm of the very small.
"We live in a quantum universe -- quantum mechanics is needed to describe the behavior of all forces and all particles at the subatomic level," Fox said. "Ultimately, we can hope to develop a 'quantum gravity' theory of these phenomena."
Superstring theory scientists predict that if particles and anti-particles (antimatter is an opposite form of normal matter) traded places and time was reversed, the world would still look the same. If any evidence is uncovered that matter and antimatter actually act differently, or violate their apparent symmetry, it could offer support for superstring theory.
"If it were proven to be violated by any physical process, even at some tiny level, then this would radically change the direction of current theoretical approaches to constructing a unified model of all the forces of nature," Fox said.
Collecting observational evidence can prove challenging, as many quantum structures are too small to probe with present-day technology on Earth, making a space-based probe a necessity.
Photons streaming from gamma-ray bursts have thus far shown no changes in the rotation of their polarity. Such a rotation would indicate a lack of symmetry if time were reversed and particles and anti-particles switched.
Studying three gamma-ray bursts with significantly more precision than ever before, Toma and his team found no change in the polarization of the photons, implying that the symmetry is consistent to at least one part in 10 million. This is a new record in constraining the rules that govern nature, and will influence attempts to create a unified theory.
The research will be published in an upcoming issue of the journal Physical Review Letters.
A powerful source
Gamma-ray bursts are brief spikes that can last from a few seconds to a few minutes. The light from them can travel billions of light-years in the form of streaming high-energy photons that are unable to penetrate Earth's atmosphere.
Emitting as much energy in a few seconds as the sun does in a lifetime, the explosions may come from flare-ups during the formation of a neutron star or black hole -- two possible outcomes of star deaths -- or the sudden collision of neutron stars. The powerful forces involved in such events accelerate photons almost to the speed of light.
Read more at Discovery News