Feb 9, 2013

Excavation Set to Shed New Light On London's Victorian Past

From a clay smoking pipe to Neolithic flint, a 19th Century garden has been revealing some of its secrets to an archaeological team from London's Kingston University.

Dr Helen Wickstead spotted an opportunity to delve below the surface of an area of land at the University's Seething Wells hall of residence after looking at historic maps and images of the area alongside the River Thames. The former industrial site had not been excavated before and she was intrigued to see whether she could find traces of a garden marked out on early maps.

"The Seething Wells site in Surbiton is of historic significance because the waterworks built there and opened in 1852 were pivotal in improving the health of Londoners. They provided clean, filtered water when cholera had been ravaging the capital," Dr Wickstead explained. "A garden on a site like this might tell us more about the people who lived and worked nearby -- did they use it for leisure, was it just decorative and reserved for the privileged, or was it used for food production? It was a time of great social change so we were keen to roll back the turf to see what we could find."

The team studied 19th Century maps from English Heritage archives, comparing them with aerial photographs taken during World War II by the Royal Air Force as well as more modern day Google Earth images. "We could see that a path existed across the site and the parched grass visible on modern satellite images also suggested its presence," Dr Wickstead said.

After digging a 10 metre square trench, the team discovered signs of a path made from cinder and gravel. "That showed us it was a functional feature rather than decorative," Dr Wickstead, who lectures in heritage, said. "Now we'd like to explore beneath it and sample the soil as it will have captured pollen from plants growing at the time."

Shells in the gravel section suggest the path was probably made from waste material from the water filter gravel beds that still exist opposite the hall of residence. But one fragment spotted by chance in the waste took the team right back to the Neolithic period. "We were very excited to find a fragment of flint that we believe is a chipping from the making of Neolithic tools," Dr Wickstead, who is also a pre-historian, said. "It could be as much as 6,000 years old. I expect it came from the river at some point and was caught up in the gravel used in the filter beds. It's an intriguing find and took us all by surprise."

The team also unearthed a fragment of red and white pottery with illustrations of two Victorian gentlemen. "I like to imagine one of those people could even be the engineer James Simpson who invented the capital's water filtration system," Dr Wickstead said.

Some more recent objects have connections to the war years. The team expected several small metal garden tags they discovered to bear the names of plants. "On closer inspection, two had names of people on them," Dr Wickstead said. "We'd love to find out more about Derek Ellis and Mabel Gower -- perhaps they worked the allotments that were on the site during World War II."

Students studying historic building conservation joined Dr Wickstead on the dig. Third year Crispin Thomas, who is particularly interested in Medieval carpentry, helped survey the ground with an auger -- a drilling device that tests resistance to see how deep top soil is. "I'd never been on an archaeological dig before and I was fascinated to see how much information could be gleaned from such a small space," he said. "So much evidence for how we got where we are today as a society, in so many aspects of life, is right there under our feet."

Read more at Science Daily

Cupid's Arrow: Light Shed On Laws of Attraction

We've heard the clichés: "It was love at first sight," "It's inner beauty that truly matters," and "Opposites attract." But what's really at work in selecting a romantic or sexual partner?

University of Notre Dame Sociologist Elizabeth McClintock studies the impacts of physical attractiveness and age on mate selection and the effects of gender and income on relationships. Her research offers new insights into why and when Cupid's arrow strikes.

In one of her studies, "Handsome Wants as Handsome Does," published in Biodemography and Social Biology, McClintock examines the effects of physical attractiveness on young adults' sexual and romantic outcomes (number of partners, relationship status, timing of sexual intercourse), revealing the gender differences in preferences.

"Couple formation is often conceptualized as a competitive, two-sided matching process in which individuals implicitly trade their assets for those of a mate, trying to find the most desirable partner and most rewarding relationship that they can get given their own assets," McClintock says. "This market metaphor has primarily been applied to marriage markets and focused on the exchange of income or status for other desired resources such as physical attractiveness, but it is easily extended to explain partner selection in the young adult premarital dating market as well."

McClintock's study shows that just as good looks may be exchanged for status and financial resources, attractiveness may also be traded for control over the degree of commitment and progression of sexual activity.

Among her findings:

  • Very physically attractive women are more likely to form exclusive relationships than to form purely sexual relationships; they are also less likely to have sexual intercourse within the first week of meeting a partner. Presumably, this difference arises because more physically attractive women use their greater power in the partner market to control outcomes within their relationships.
  • For women, the number of sexual partners decreases with increasing physical attractiveness, whereas for men, the number of sexual partners increases with increasing physical attractiveness.
  • For women, the number of reported sexual partners is tied to weight: Thinner women report fewer partners. Thinness is a dimension of attractiveness for women, so is consistent with the finding that more attractive women report fewer sexual partners.

Another of McClintock's recent studies (not yet published), titled "Desirability, Matching, and the Illusion of Exchange in Partner Selection," tests and rejects the "trophy wife" stereotype that women trade beauty for men's status.

"Obviously, this happens sometimes," she says, pointing to Donald Trump and Melania Knauss-Trump as an example.

"But prior research has suggested that it often occurs in everyday partner selection among 'normal' people … noting that the woman's beauty and the man's status (education, income) are positively correlated, that is, they tend to increase and decrease together."

According to McClintock, prior research in this area has ignored two important factors:

"First, people with higher status are, on average, rated more physically attractive -- perhaps because they are less likely to be overweight and more likely to afford braces and nice clothes and trips to the dermatologist, etc.," she says.

"Secondly, the strongest force by far in partner selection is similarity -- in education, race, religion and physical attractiveness."

After taking these two factors into account, McClintock's research shows that there is not, in fact, a general tendency for women to trade beauty for money.

Read more at Science Daily

Feb 8, 2013

Peer Review Matters to the Public

A new guide to peer review has just been launched to help the public make sense of research claims.

People are bombarded with claims in newspapers and on the internet that are based on scientific studies. When faced with a headline that suggests an Alzheimer's drug increases the risk of heart attack or that watching TV is bad for children's mental health, or that pesticides are causing a decline in bee populations, people have to work out what to believe. Which claims should be taken seriously? Which are 'scares'?

I Don't Know What to Believe: Making Sense of Science Stories... explains the peer review process -- the system researchers use to assess the validity, significance and originality of papers. It captures experiences and insights from editors and scientists and encourages people to ask "Is it peer reviewed?" when reading science stories.

A similar publication launched in the UK is now used by health workers, librarians, public-health officials, policy-makers, technology companies, safety bodies, popular writers, educators, parenting groups and local government. These are the people who are speaking directly with the public everyday and answering their questions.

Understanding peer review and asking about the status of claims is important to society because it helps people make decisions.

Download the guide: http://www.senseaboutscience.org/resources.php/116/Embargoed_until_00.01Feb8th2013_IDKWTB_web.pdf

Bob Meyers, President & COO, National Press Foundation said: "Evidence-based journalism needs evidence-based science."

Dr Virginia Barbour, Medicine Editorial Director, Public Library of Science and Chair, Committee on Publication Ethics: "Peer review is an important part of the scientific process, and one indicator that can help readers distinguish in the mass of science they hear reported every day between what they can have confidence in and what they should treat with more caution. Furthermore, understanding how peer review works gives an insight into how science itself is done: I Don't Know What to Believe bridges a crucial gap in understanding between scientists and the public."

Read more at Science Daily

Top 12 Most Amazing Snakes

The second new moon after the winter solstice has ushered in the Year of the Snake, which we’re marking with snake extremes -- from largest to most venomous.

While Chinese New Year is just underway, 2013 began with the discovery of a new venomous snake in January. The snake, Thelotornis usambaricus, was found in the northern Mozambique province of Nampula. It’s a type of back-fanged snake that belongs to the family Colubridae, illustrated here with the species Coluber caspius.

These snakes can be deadly. Their venom destroys red blood cells, disrupts clotting and can lead to tissue damage.

The Largest Snake that Ever Lived

The largest snake on Earth was the Titanoboa, which lived among the dinosaurs and ate their young, among other things. It weighed 2,500 pounds and grew to 43 feet long.

“It was not necessarily a specialized constrictor, but it clearly grabbed dinosaur hatchlings and gobbled them down,” Jason Head, a paleontologist and assistant professor in the Department of Biology at the University of Toronto Mississauga, told Discovery News.

Largest Living Snake

The reticulated python, found in Southeast Asia, is the world’s longest snake still in existence. Adults can grow to over 28 feet in length.

Smallest Snake

The smallest living snake is Leptotyphlops carlae, which measures just 3.9 inches long. It was discovered four years ago under a rock on the western Atlantic island of Barbados.

Evolutionary biologist Blain Hedges of Penn State University told Discovery News that “almost anything could be a predator (of the tiny snake), including centipedes and spiders.”

Read more at Discovery News

Picasso's Genius Revealed: He Used Common House Paint

Pablo Picasso, famous for pushing the boundaries of art with cubism, also broke with convention when it came to paint, new research shows. X-ray analysis of some of the painter's masterworks solves a long-standing mystery about the type of paint the artist used on his canvases, revealing it to be basic house paint.

Art scholars had long suspected Picasso was one of the first master artists to employ house paint, rather than traditional artists' paint, to achieve a glossy style that hid brush marks. There was no absolute confirmation of this, however, until now.

Physicists at Argonne National Laboratory in Lemont, Ill., trained their hard X-ray nanoprobe at Picasso's painting "The Red Armchair," completed in 1931, which they borrowed from the Art Institute of Chicago. The nanoprobe instrument can "see" details down to the level of individual pigment particles, revealing the arrangement of particular chemical elements in the paint.

The analysis showed that Picasso used enamel paint that matches the precise chemical composition of the first brand of commercial house paint, called Ripolin. The researchers were able to compare the painting's pigment with those of paints available at the time by analyzing decades-old paint samples bought on eBay.

Read more at Discovery News

The Hypersonic Spaceplanes of Yesteryear

Last month, the German Aerospace Center announced its SpaceLiner. This still-on-paper hypersonic suborbital spaceplane is theoretically capable of taking up to 50 passengers at a time to destinations halfway across the world in a few hours. It’s an exciting prospect, seeing the curvature of the Earth during a business trip. But it isn’t a new idea. A host of science fiction writers have explored this, as did Walter Dornberger, former director of the V-2 program at Peenemunde in Germany, in 1956.

In 1952, Dornberger was a new immigrant to the United States working as a guided missile consultant for Bell Aircraft in Ohio. He pitched the idea of a hypersonic manned glider to the Air Force as an efficient and reusable precision bomber. The Air Force, intrigued, pursued the idea; it became the basis of the failed Dyna-Soar program. But for Dornberger, a hypersonic gliding bomber was a step on the way to suborbital hypersonic air travel.

Inspired by the rapid growth of aviation – from the Wright brothers’ first flight to Mach 2 in half a century – he imagined a future where hypersonic passenger flights would be commonplace in another 25 years. But the first flights could be sooner. Writing in 1956, he saw that the nation had the technology to start exploring the world of hypersonic air travel with glider mounted on boosters. He called them Ultra Planes, and imagined them taking off from commercial airports around the world.

A glider would be mounted on the “back” of a booster such that the flat, gliding bottoms of both vehicles faced the same way. Once mated, the 90-foot tall pair would be turned vertically and loaded on a train that would carry it, by rail, to its underground launch canyon – image a missile silo big enough for crews to access both vehicles for things like fueling and maintenance. Passengers would arrive at the canyon, which would have an ordinary gate number, by bus since it would be too risky to connect a launch canyon to the terminal by jetway.

With the vehicle ready, the crew and passengers would board, the latter sitting in swiveling chairs that would keep them upright throughout the journey. Once their seat belts were firmly fastened, the booster would roar to life and launch, carrying the glider aloft with it.

For the first minute and a half, the glider’s pilot would be in control of both vehicles; the booster’s skeleton crew would be on standby. Then the stages would separate. The glider would slide off guide rails on the booster’s “back” and the pilot would ignite its engine. The glider would rocket up to 140,000 feet at a top speed of 8,400 miles per hour. At the same time, the booster’s crew would take control of their vehicle and return to the airport for refueling and launch with another glider in tow.

Pilot-controlled sun filters on the window’s would ensure passengers had a safe view of the curvature of the Earth as the glider reached its peak altitude. Then, as dictated by the flight plan, the glider’s pilot would shut off its engine and begin a steady glide his designated airport. The remaining ride would be silent and pleasant with stunning views unhampered by clouds out of every window. Stars that we never see from Earth would be as bright as the moon.

The glider would land, unpowered, like a traditional airplane on a runway. Passengers would disembark by a rolling stairway right onto the tarmac then the glider would be towed to a launch canyon where it would be mated to another booster and fueled for its next launch.

Read more at Discovery News

Feb 7, 2013

An Asteroid Killed the Dinosaurs: New Evidence

The idea that a cosmic impact ended the age of dinosaurs in what is now Mexico now has fresh new support, researchers say.

The most recent and most familiar mass extinction is the one that finished the reign of the dinosaurs — the end-Cretaceous or Cretaceous-Tertiary extinction event, often known as K-T. The only survivors among the dinosaurs are the birds.

Currently, the main suspect behind this catastrophe is a cosmic impact from an asteroid or comet, an idea first proposed by physicist Luis Alvarez and his son geologist Walter Alvarez. Scientists later found that signs of this collision seemed evident near the town of Chicxulub (CHEEK-sheh-loob) in Mexico in the form of a gargantuan crater more than 110 miles (180 kilometers) wide. The explosion, likely caused by an object about 6 miles (10 km) across, would have released as much energy as 100 trillion tons of TNT, more than a billion times more than the atom bombs that destroyed Hiroshima and Nagasaki.

However, further work suggested the Chicxulub impact occurred either 300,000 years before or 180,000 years after the end-Cretaceous mass extinction. As such, researchers have explored other possibilities, including other impact sites, such as the controversial Shiva crater in India, or even massive volcanic eruptions, such as those creating the Deccan Flats in India.

Timing of an impact

New findings using high-precision radiometric dating analysis of debris kicked up by the impact now suggest the K-T event and the Chicxulub collision happened no more than 33,000 years apart. In radiometric dating, scientists estimate the ages of samples based on the relative proportions of specific radioactive materials within them.

Read more at Discovery News

Furry Insect-Eater Tops Our Family Tree

Meet your ancestor: This small and furry scampering insect-eater lies at the base of the family tree for humans and most mammals, according to the largest-yet study of mammalian evolution.

The agile animal is the earliest among placental mammals -- the largest branch of the mammal tree consisting of more than 5,100 living species. Only marsupials, such as kangaroos, and monotremes (egg-laying mammals including the platypus and echidna) fall outside of that huge group.

The mammal "had a diet of insects, a fleshy nose, a light underbelly in its fur, and a long tail," said Maureen O'Leary, an associate professor in the Department of Anatomical Sciences in the School of Medicine at Stony Brook University. O'Leary was lead author of a study about the mammal in the latest issue of Science.

"It was larger than a mouse, but smaller than a rat," added O'Leary, who is also a research associate at the American Museum of Natural History

"As for its bones, it lacked special bones that are found near the pelvis, and in its ear had a small bone for hearing that was shaped like a stirrup."

Such a detailed description was made possible due to an unprecedented combining of both DNA and anatomical data for placental mammals. Humans again fall into that mammal group, which is distinguished by certain reproductive features and skeletal traits.

Recording of the data employed a system called MorphoBank. Its data set, which includes more than 4,500 traits detailing characteristics such as hair types and teeth structure, is 10 times larger than what was previously used for studies of mammal relationships.

In addition to revealing what the "mother" of most mammals looked like, the study shows that placental mammals arose 200,000 to 400,000 years after the extinction of non-avian dinosaurs about 65 million years ago.

"This is about 36 million years later than the prediction based on purely genetic data," said co-author Marcelo Weksler of the Museu National-UFRJ in Brazil.

Somehow the distant relative of mammals that led to the "mother" of our species and others survived the asteroid crash, dramatic climate change, and other happenings that did in the dinos.

"Other species that survived are some crocodiles, turtles and flowering plants," O'Leary said.

The newly constructed mammal family tree indicates that the fragmentation of Gondwana- one of two supercontinents formerly part of Pangaea- came well before the origin of placental mammals, co-author John Wible of the Carnegie Museum of Natural History shared.

This negates an earlier theory, which held that mammal diversification was tied to the breakup of the supercontinent. It previously was thought that this breakup put the early mammals in different environments, leading to their different evolutionary paths and the diversity that we see today among mammals.

It now could be, however, that the earliest mammals traveled far distances of their own accord and just evolved their broad diversity over long periods of time.

Yet another finding of the extensive study is that a branch of the placental mammal tree called Afrotheria (a group ranging from elephants to aardvarks that today lives in Africa) did not originate in Africa, but rather in the Americas.

Read more at Discovery News

Half-Million-Year-Old Human Jawbone Found

Scientists have unearthed a jawbone from an ancient human ancestor in a cave in Serbia.

The jawbone, which may have come from an ancient Homo erectus or a primitive-looking Neanderthal precursor, is more than 397,000 years old, and possibly more than 525,000 years old. The fossil, described today (Feb. 6) in the journal PLOS ONE, is the oldest hominin fossil found in this region of Europe, and may change the view that Neanderthals, our closest extinct human relatives, evolved throughout Europe around that time.

"It comes from an area where we basically don't have anything that is known and well- published," said study co-author Mirjana Roksandic, a bioarchaeologist from the University of Winnipeg in Canada. "Now we have something to start constructing a picture of what's happening in this part of Europe at that time."

Cave diggers

In 2000, Roksandic and her colleagues began excavating a cave in Balanica, Serbia, that contained ancient archaeological remains. While they were away, rogue diggers secretly dug a deeper pit within the cave, hoping to do their own excavations. Because the site had already been disturbed, the team then decided to probe deeper below the pit's bottom, Roksandic told LiveScience.

About 5.9 inches (15 centimeters) below the surface the team found an ancient jawbone fragment with three molars still intact.

Using several dating techniques, the team determined the fragment was definitely older than 397,000 years and perhaps older than 525,000 years.

The jawbone lacked several characteristic Neanderthal features, including distinctive chewing surfaces on the teeth that show up in Western Europe at that time. Instead, the fossil resembled the more primitive Homo erectus.

Back then, the cave may have been a hyena den, though the researchers can't say whether a hyena actually brought the human remains into its den.

Oldest specimen

In the past, anthropologists assumed that Neanderthals were widespread throughout Europe, basing that assumption on Neanderthal fossils almost exclusively found in Western Europe, Roksandic said.

The new findings suggest that Neanderthals may not have evolved in this region of Southeastern Europe, at least during this time. Instead, during several ice ages, rising glaciers over the past eons cut off Western Europe from the rest of the continent, and this isolation likely contributed to the evolution of Neanderthals' distinctive features from the more primitive Homo erectus.

Ancient humans in Southeastern Europe, by contrast, were never cut off due to rising glaciers.

"So there is no pressure on them to develop into something different," she said.

But not everyone is convinced of this interpretation.

Read more at Discovery News

Gamma-Ray Burst Blasted 8th Century Earth

Cosmic radiation is constantly bombarding our planet, fragmenting atoms in the upper atmosphere as it does. Every now and again, however, vast cosmic events can have a more dramatic effect on our world.

Occasionally considered as having potentially catastrophic consequences, gamma ray bursts are amongst the most powerful single events in the known universe – so powerful that we can detect them from the other side of the Universe. Now it looks as if Earth was struck by one about 1,200 years ago.

Last year, a researcher named Fusa Miyake discovered high levels of carbon-14 in the rings of ancient cedar trees in Japan. Carbon-14 is a rare isotope of carbon, and the tree rings enabled it to be accurately dated to the year 775 CE. This also coincided with high levels of beryllium-10 found in Antarctica and dated to the same time. Some clever deductive reasoning by Valeri Hambaryan and Ralph Neuhäuser suggests that a gamma ray burst might have been to blame.

Cosmic rays striking our atmosphere cause nitrogen atoms to fragment and decay, producing both carbon-14 and beryllium-10, but the levels of these two isotopes were over ten times as high as normal galactic cosmic rays could explain. In order to explain the amount of carbon-14 observed, it was found that gamma rays would need a total energy of 700 quadrillion Joules — equivalent to 167.3 megatons of TNT!

Of course, there are other events which could be responsible, but none of them seem to fit. An extra powerful solar flare could supply enough energy, but the energy needed was about 20 times that that would be expected from the solar cycle at the time. Solar flares also blast Earth with charged particles which would create dramatic aurorae over Earth’s North and South Poles. But no such aurorae were recorded in any historic texts.

A nearby supernova could also be to blame. Supernovae are reliably recorded in historic texts, often referred to as “guest stars”. However there’s no mention of any supernova at the time. While it’s possible for the visible light from a supernova to be blocked by interstellar dust, that can’t be the case here; if a supernova was behind the carbon-14 in 775 CE, it would have had to be close. Close enough that there isn’t enough interstellar dust to block out all of the light. What’s more, astronomers would have found the remnant of a supernova that close and recent by now.

A third discounted possibility is that of a magnetar flare — a sudden burst of x-rays and gamma rays from a nearby neutron star with a powerful magnetic field. Magnetars occasionally suffer from starquakes. Violent ruptures in the surface of the neutron star, which disturb the magnetic field and cause powerful gamma ray emissions. Such magnetar flares have been detected here on Earth before (there have been three since the 1970s). Once again, the problem with this idea is that there are no neutron stars close enough to Earth to deliver such a powerful blast of gamma rays.

Hambaryan and Neuhäuser found that the only thing which could properly explain the carbon-14 was a short gamma ray burst — and after reading all of the other possibilities they considered, they make a fairly convincing argument. Lasting for just a couple of seconds, short bursts are believed to be typically caused by two neutron stars colliding together. Because neutron stars are surprisingly small, they collide rapidly, obliterating each other and usually forming a black hole in the process.

If a short gamma ray burst was responsible for the 775 CE event, then it must have been around 3,000 – 12,000 light-years away. Any closer, and it would probably have caused the extinction of some life on Earth. If the hypothesis turns out to be true, then the culprit is still at large. Astronomers could attempt to identify any suspects by looking for a black hole, aged about 1,200 years, within 120,000 light-years from Earth.

Read more at Discovery News

Mystery Mini Moons: How Many Does Earth Have?

Earth's gravity may not have the gravitas of Jupiter, but the planet regularly plucks small asteroids passing by and pins them into orbit. The mini-moons don't stay for long. Within a year or so they resume their looping, twisting paths like crazy straws around the sun. But others arrive to take their place.

Simulations show that two asteroids the size of dishwashers and a dozen half-meter (1.6 feet) in diameter are orbiting Earth at any given time. Every 50 years or so something the size of a dump truck arrives. So far, there's been just one confirmed sighting.

"We'd eventually like to see a mission to a mini-moon," astronomer Robert Jedicke, with the University of Hawaii, said this week at a workshop in Huntsville, Ala., to discuss proposals for two spare Hubble-class spy telescopes donated to NASA by the National Reconnaissance Office.

Jedicke would like to use one of the telescopes to hunt for near-Earth objects, including mini-moons, which could be captured whole and brought to the ground for study.

"It's the Rosetta stone of the solar system. You bring back a chunk of material that's never been processed through the atmosphere, that's not been sitting on the ground. It's going to be a tremendous wealth of information about how the solar system formed -- even more so if you can bring back more than one and get different types of material," Jedicke told Discovery News.

"The great thing is you don't have to go very far," he added. "These things are sitting there right in geocentric orbit and they're relatively easy to get to."

But hard to find.

A paper published last year showed that, in theory, a cloud of temporarily captured asteroids circles Earth at all times, but that the largest object is just about a meter (3 feet) in diameter.

"These are really difficult to detect with current technology," said astronomer Paul Chodas, with NASA's Near Earth Object program at the Jet Propulsion Laboratory in Pasadena, Calif.

So far, the only confirmed captured asteroid that orbited Earth was RH120, which most recently visited from September 2006 to June 2007. Initially, the object was suspected of being a spent upper-stage motor from an Apollo rocket, but follow-up observations by ground-based radars determined the object was not metallic.

"There is great interest in tracking these Temporarily Captured Objects (TCOs), because for a short time they are easily accessible for both scientific study and, possibly, eventually, resource utilization," Chodas wrote in an email to Discovery News.

In addition to being small, mini-moons are difficult to find because they only hang around for a relatively short time, between six and 18 months.

"We would want to discover one of these as soon after capture (by Earth’s gravity) as possible to have enough time to get a spacecraft out there, and then still have time to study the object before it escapes back into heliocentric orbit," Chodas said.

In addition to science, there is economic interest in asteroids. Two U.S. firms, Planetary Resources and Deep Space Industries, announced plans last year to mine asteroids for raw materials. Both companies are developing precursor missions to scout potential targets.

"Maybe you're not going to mine a half-meter diameter wide asteroid, but you can test out your techniques on it," Jedicke said.

Hunting mini-moons wouldn't be the telescope's only job.

"It would be best asteroid survey ever of the entire solar system," Jedicke said.

Read more at Discovery News

Feb 6, 2013

35 Ancient Pyramids Discovered in Sudan

At least 35 small pyramids, along with graves, have been discovered clustered closely together at a site called Sedeinga in Sudan.

Discovered between 2009 and 2012, researchers are surprised at how densely the pyramids are concentrated. In one field season alone, in 2011, the research team discovered 13 pyramids packed into roughly 5,381 square feet (500 square meters), or slightly larger than an NBA basketball court.

They date back around 2,000 years to a time when a kingdom named Kush flourished in Sudan. Kush shared a border with Egypt and, later on, the Roman Empire. The desire of the kingdom's people to build pyramids was apparently influenced by Egyptian funerary architecture.

At Sedeinga, researchers say, pyramid building continued for centuries. "The density of the pyramids is huge," said researcher Vincent Francigny, a research associate with the American Museum of Natural History in New York, in an interview with LiveScience. "Because it lasted for hundreds of years they built more, more, more pyramids and after centuries they started to fill all the spaces that were still available in the necropolis."

The biggest pyramids they discovered are about 22 feet (7 meters) wide at their base with the smallest example, likely constructed for the burial of a child, being only 30 inches (750 millimeters) long. The tops of the pyramids are not attached, as the passage of time and the presence of a camel caravan route resulted in damage to the monuments. Francigny said that the tops would have been decorated with a capstone depicting either a bird or a lotus flower on top of a solar orb.

The building continued until, eventually, they ran out of room to build pyramids. "They reached a point where it was so filled with people and graves that they had to reuse the oldest one," Francigny said.

Francigny is excavation director of the French Archaeological Mission to Sedeinga, the team that made the discoveries. He and team leader Claude Rilly published an article detailing the results of their 2011 field season in the most recent edition of the journal Sudan and Nubia.

The inner circle

Among the discoveries were several pyramids designed with an inner cupola (circular structure) connected to the pyramid corners through cross-braces. Rilly and Francigny noted in their paper that the pyramid design resembles a "French Formal Garden."

Only one pyramid, outside of Sedeinga, is known to have been constructed this way, and it's a mystery why the people of Sedeinga were fond of the design. It "did not add either to the solidity or to the external aspect of the monument," Rilly and Francigny write.

A discovery made in 2012 may provide a clue, Francigny said in the interview. "What we found this year is very intriguing," he said. "A grave of a child and it was covered by only a kind of circle, almost complete, of brick." It's possible, he said, that when pyramid building came into fashion at Sedeinga it was combined with a local circle-building tradition called tumulus construction, resulting in pyramids with circles within them.

Read more at Discovery News

Artifacts from the Oldest Known Museums

Multiple artifact collections unearthed in the U.K. suggest that the earliest known museums could date to around 680 B.C. or even earlier. They force a rethinking of what museums are, and how certain ancient populations valued treasured objects.

Museums, by their definition, are institutions or organized groups that conserve a collection of artifacts.

Such a collection, now called the "Tisbury Hoard," was found in a field in Wiltshire, England.

"It contains around 114 bronze weapons, tools and ornaments, and was probably buried in the early Iron Age, in or towards the end of the seventh century B.C.," Dot Boughton, a researcher with the Portable Antiquities Scheme, wrote in a paper published in the latest issue of British Archaeology.

While the objects were buried simultaneously, they cover a span of 1,000 years.

At first this might appear to be some metalworker's sample kit, or an individual's private collection. But since multiple hoards of this nature featuring different types of objects have been found in key locations in the U.K., Boughton believes that the collections were "community museums."

One of the first objects to be found from the Tisbury Hoard was this spearhead. In total, 40 pieces of weaponry were included in this particular collection.

Often craftsmen recycled old metal objects, but this and many others appear intentionally to have been saved and grouped with additional artifacts.

This bent knife blade was also recovered at the Wiltshire dig.

Archaeologist Mike Pitts, who edits British Archaeology, told Discovery News, "Hoards of prehistoric bronzes are common in northern Europe, and have become even more so in Britain with the success of the British Museum's Portable Antiquities Scheme, which brings metal detectorists and archaeologists together.

Usually the stuff in the hoards is more or less contemporary, often interpreted as a smith's work in progress, scrap and raw materials; or the stock of a trader."

But the latest discoveries have experts such as himself and Boughton thinking "there has to be another explanation" for at least certain artifact groupings. The community museums, he shares, perhaps could have been "in the form of shrines" offering "respect for distant ancestors."

Read more at Discovery News

Weird Underwater Waves Spotted from Space

In the ocean, there are more waves than meet the eye.

Below the whitecaps breaking on the sea surface, so-called internal waves ripple through the water. These waves can travel long distances, but rarely does evidence of their existence surface — unless you're looking down from space, that is.

This photograph, taken on Jan. 18 by a crewmember on the International Space Station, shows internal waves north of the Caribbean island of Trinidad, as featured by NASA's Earth Observatory. From space, the appearance of the waves is enhanced due to reflected sunlight, or sunglint, aimed back at the space station, making the waves visible to an astronaut's camera.

The most prominent waves can be seen in the upper left of the photograph, moving in from the northwest due to tidal flow toward Trinidad, according to the Earth Observatory. Another set can be seen moving in from the northeast, likely created at the edge of the continental shelf, where the seafloor abruptly drops off, the site reported.

Internal waves are seen throughout Earth's oceans and atmosphere, according to MIT's Experimental and Nonlinear Dynamics Lab. They are created by differences in density of water layers (from changes in temperature or salt content, for example) when that water moves over a feature such as an underwater mountain or a continental shelf. The waves are huge, with heights up to 100 meters (about 330 feet) and widths that span hundreds of miles, according to a 2010 MIT press release on a new method for studying the waves.

Read more at Discovery News

Nearest 'Second Earth' May Be Right Next Door

The nearest habitable planet beyond the solar system may be relatively close to Earth, though the parent star would be a cooler and redder than the sun -- an interesting implication for any indigenous life.

Extrapolating from findings by NASA's planet-hunting Kepler Space Telescope, scientists on Wednesday said roughly six percent of so-called red dwarf stars have Earth-sized planets properly positioned around their parent stars so that liquid water could exist on their surfaces.

Water is necessary for life -- at least life as we know it.

While Kepler's prime mission is to find Earth-sized worlds around sun-like stars, its observations of red dwarf stars are providing additional food for thought, particularly because red dwarfs are by far the most common type of star in the galaxy. Typically, these stars are about one-third the size of the sun and about 1,000 times dimmer. Three out of every four stars in the galaxy are red dwarfs, adding up to about 75 billion.

At least one red dwarf has been determined to host a planet that is roughly twice the size of Earth.

"We decided that it would make sense to see if we could look at the red dwarfs in Kepler (data) whether we would find the occurrence of planets would be consistent," with the earlier study, astronomer Courtney Dressing, with the Harvard-Smithsonian Center for Astrophysics, told Discovery News.

The team looked at 95 candidate planets circling red dwarf stars observed by Kepler and found that at least 60 percent have planets smaller than Neptune. Most were not the right size or temperature to be Earth-like, but three were found to be both warm and approximately Earth-sized. Scientists, however, do not have enough information to assess if they are rocky worlds, like Earth.

Nevertheless, statistically that would mean six percent of all red dwarf stars should have a Earth-sized planet, Dressing said, adding that since 75 percent of the closest stars are red dwarfs, the nearest Earth-like world may be just 13 light-years away.

A light year is the distance that light, which moves at about 186,000 miles per second, can travel in one year -- roughly 6 trillion miles, a relative stone's throw in cosmic scales.

Read more at Discovery News

Feb 5, 2013

Moles Can Smell in Stereo

Humans and most other mammals can see and hear in stereo, but now it’s known that a ubiquitous garden critter can smell in stereo too.

The super smeller is the common mole, according to a paper in the journal Nature Communications. This is the same animal that might be out in your lawn and garden right this very minute, digging holes and searching for something tasty to eat. We don’t often get to see moles up close, but as you can tell from the photo (above), it’s all about the nose.

Stereo smelling means that each nostril takes in different odors, with the brain recognizing those differences. The discovery is a first, since no mammals were thought to have this ability.

“I came at this as a skeptic,” neuroscientist Kenneth Catania of Vanderbilt University was quoted as saying in a press release. “I thought the moles’ nostrils were too close together to effectively detect odor gradients. The fact that moles use stereo odor cues to locate food suggests other mammals that rely heavily on their sense of smell, like dogs and pigs, might also have this ability.”

Catania’s study created a radial arena with food wells spaced around a 180-degree circle with the entrance for the mole in the center. He then ran a number of trials with a mole food fave — pieces of earthworm — placed randomly in different wells. The chamber was temporarily sealed so Catania could detect each time the mole sniffed by the change in air pressure.

“It was amazing,” he said. ”They found the food in less than five seconds and went to the right food well almost every time. They have a hyper-sensitive sense of smell.”

He noticed a pattern. When a mole would enter a chamber, it moved its nose back and forth as it sniffed, but then the mole seemed to zero in on the food source, moving in a direct path. That’s when the “stereo sniffing” idea dawned on Catania.

When the moles’ left nostrils were blocked, the animals’ paths consistently veered off to the right. When their right nostrils were blocked, they consistently veered to the left. They still found the food, but it took a much longer time.

Catania conducted further tests, inserting plastic tubes in both of the moles’ nostrils. He crossed these tubes such that the right nostril was sniffing air on the animal’s left and the left nostril was sniffing air on the animal’s right. When their nostrils were crossed in this fashion, the animals searched back and forth and frequently could not find the food at all.

The conclusion? Moles indeed smell in stereo, as he suspected.

Catania said he doubts humans have this ability.

Tests for this aren’t difficult to do on humans, he said. “You can ask a blindfolded person to tell you which nostril is being stimulated by odors presented with tubes inserted in the nose.”

Read more at Discovery News

Richard III May Have Had a Brummie Accent

Not only have British experts reconstructed the face of king Richard III — they have recreated what he may have sounded like.

Despite being the patriarch of the House of York, Richard likely spoke with an accent associated with West Midlands rather than northern England, according to language expert Philip Shaw, from the University of Leicester’s School of English.

“That’s an accent you might well see in London,” Shaw said.

The researcher used two letters penned by England’s last medieval king more than 500 years ago to investigate Richard III’s language, spelling and grammar.

While secretaries would have written most of the king’s letters, two missives seem to be original.

One letter was written in 1469, when Richard was still the Duke of Gloucester, the other dates to 1483, when he was king.

In the first letter Richard, who was traveling with Edward IV to quell a disturbance in Yorkshire, urgently asks for a loan of £100 from the Chancellor of the Duchy of Lancaster. To emphasize the urgency of his request, the king added a two-line note in his own hand.

A personal note also appears in the second letter, revealing Richard’s urgent call for the Great Seal to be sent to him as he was trying to suppress Duke of Buckingham’s rebellion.

“Unlike today, individuals were more likely to spell words in ways that reflected their local dialect. Therefore, by looking at Richard’s writing, I was able to pinpoint spellings that may provide some clues to his accent,” Shaw said in a statement.

For example, elongated vowels are a distinctive aspect of Richard’s speech patterns.

“There are interesting differences with words like ‘say’ and ‘pray’ and ‘fail’ where we have this ‘a’ sound which is what we call a diphthong — a glide from one sound to another,” Shaw said.

He noted that Richard may well have used a pure vowel in his speech — something like ‘saa’ or ‘praa’ rather than “say” and “pray.”

According to Shaw, the two postscripts show at least one spelling that may suggest a West Midlands accent.

Read more at Discovery News

Richard III's Face Revealed

Advanced CT scans and wax modeling have revealed the face of King Richard III

Showing a hint of a smile, a prominent chin, and slightly arched nose, the facial reconstruction is based on a skull found along with other bones just 2 feet beneath a car park in Leicester, UK, last September.

The reconstruction follows confirmation that the skeleton was that of the king killed in battle more than 500 years ago.

According to Richard Buckley, the lead archaeologist on the project at the University of Leicester, DNA tests had proved “beyond reasonable doubt” that the bones were those of the last Plantagenet king.

The model was created by digitizing a three-dimensional image of the complete skull and using the bone structure to estimate the thickness of the various layers of muscle and skin.

“When the 3D digital bust was complete it was replicated in plastic using a rapid prototyping system,” Caroline Wilkinson, professor of craniofacial identification at Dundee University, UK, said.

The head was painted and textured with prosthetic eyes. Using portraits as reference, the researchers created a realistic and royal appearance by dressing the king with a wig, hat and clothing.

According to historian John Ashdown-Hill, the model is so lifelike that it is “almost like being face to face with a real person.”

Although the essential features of Richard are quite similar to those shown in various depictions of the king, of whom no contemporary portraits exist, the model reveals a more pleasant and younger face.

Indeed, many of the later portraits of Richard showed him with a rather mean face — quite appropriate for the bloodthirsty usurper depicted by Shakespeare.

“It doesn’t look like the face of a tyrant… He’s very handsome. It’s like you could just talk to him, have a conversation with him right now,” Philippa Langley, a member of the Richard III Society who instigated the search for the skeleton, told Channel 4′s documentary “King in a Car Park.”

Richard III was killed in 1485 in the Battle of Bosworth, which was the last act of the decades-long fight over the throne known as War of the Roses. The king was defeated by Henry Tudor, who became King Henry VII.

Examinations of the skeleton revealed that Richard III was 5 feet, 8 inches tall and had a slender, almost feminine physique.

He suffered from scoliosis, a severe curvature of the spine, in line with the hunchback king described by Shakespeare.

Read more at Discovery News

Neanderthals Died Out Earlier Than Thought

Neanderthals may have died out earlier than before thought, researchers say.

These findings hint that Neanderthals did not coexist with modern humans as long as previously suggested, investigators added.

Modern humans once shared the planet with now-departed human lineages, including the Neanderthals, our closest known extinct relatives. However, there has been heated debate over just how much time and interaction, or interbreeding, Neanderthals had with modern humans.

To help solve the mystery, an international team of researchers investigated 215 bones previously excavated from 11 sites in southern Iberia, in an area known as Spain today. Neanderthals entered Europe before modern humans did, and prior research had suggested the last of the Neanderthals held out in southern Iberia until about 35,000 years ago, potentially sharing the region with modern humans for thousands of years.

Their data suggest that modern humans and Neanderthals may have actually lived in the area at completely different times, never crossing paths there at all. Even so, these findings do not call into question whether modern humans and Neanderthals once had sex — the findings simply indicate this interbreeding must have occurred earlier, before modern humans entered Europe.

"The genetic evidence for interbreeding — 1 to 4 percent Neanderthal DNA in present-day modern humans — suggests that interbreeding probably occurred before the period we are looking at in the Levant, the region around Israel and Syria, when modern humans first migrated out of Africa," researcher Rachel Wood, an archaeologist and radiocarbon specialist at Australian National University in Canberra, told LiveScience.

Dating bones

Scientists discover the ages of artifacts and fossils using a variety of techniques. For instance, radiocarbon dating determines the age of biological remains based on the ratio between the carbon isotopes (atoms of the same element with different numbers of neutrons) carbon-12 and carbon-14 it holds — this proportion changes as radioactive carbon-14 breaks down while stable carbon-12 does not. Researchers can also look at the layers of soil and rock in which objects are found — if these layers were not disturbed over the years, then objects in the same layer should be the same age.

Read more at Discovery News

Feb 4, 2013

Oldest Spider Crabs Discovered in Fossil Reef

The remains of eight new species of crustaceans, including the oldest known spider crabs that lived 100 million years ago, have been uncovered in a fossil reef in northern Spain, scientists report.

The fossils were found in the abandoned Koskobilo quarry alongside other species of decapod crustaceans (a group that includes crabs, shrimp and lobsters). The two oldest-known spider crabs, named Cretamaja granulata and Koskobilius postangustus, are much older than the previous record holder, said study author Adiël Klompmaker, a postdoctoral researcher at the Florida Museum of Natural History at the University of Florida.

"The previous oldest one was from France and is some millions of years younger," Klompmaker told LiveScience, referring to the spider crabs. "So this discovery in Spain in quite impressive and pushes back the origin of spider crabs as known from fossils."

C. granulatawas about 0.6 inches (15 millimeters) long and showed distinctive features to suggest it was a spider crab, including two diverging spines coming out of its rostrum (the extended portion of the carapace, or shell, in front of the eyes) and a somewhat pear-shaped carapace. The fossil spider crab also sported spines on its sides at the front of the body.

The reef where they were found seems to have vanished shortly after these creatures lived. "Something must have happened in the environment that caused reefs in the area to vanish, and with it, probably many of the decapods that were living in these reefs," Klompmaker said. "Not many decapods are known from the time after the reefs disappeared in the area," added Klompmaker, who details the findings in a forthcoming issue of the journal Cretaceous Research.

With a team of researchers from the United States, the Netherlands and Spain, Klompmaker collected fossils in the Koskobilo quarry in 2008, 2009 and 2010.

"We went there in 2008, and in the first two hours found two new species," Klompmaker said in a statement. "That's quite amazing — it just doesn't happen every day."

With the new findings, some 36 decapod species are known to have existed at the abandoned quarry, making it one of the most diverse localities for decapods during the Cretaceous period (145 million to 66 million years ago), Klompmaker said.

The researchers also found there were more diverse ancient decapods living within the reefs — where they fed, mated and sought shelter — than in other parts of the ocean.

"One of the main results of this research is that decapod crustaceans are really abundant in reefs in the Cretaceous," Klompmaker wrote in an email. "The presence of corals seemed to promote decapod biodiversity as early as 100 million years ago and may have served as nurseries for speciation."

Last year, Klompmaker reported finding fossils of tiny lobsters huddled together in the seashell of an extinct mollusk known as an ammonoid. The "embracing" lobsters, found in a rock quarry in southern Germany, suggested these fearsome-looking crustaceans were sociable as long ago as 180 million years, when the little crustaceans lived.

Read more at Discovery News

Confirmed! Bones of King Richard III Found

The body of the lost and vilified English king Richard III has finally been found.

Archaeologists announced today (Feb. 4) that bones excavated from underneath a parking lot in Leicester, "beyond reasonable doubt," belong to the medieval king. Archaeologists announced the discovery of the skeleton in September. They suspected then they might have Richard III on their hands because the skeleton showed signs of the spinal disorder scoliosis, which Richard III likely had, and because battle wounds on the bones matched accounts of Richard III's death in the War of the Roses.

The announcement comes a day after the archaeologists had released an image of the king's battle-scarred skull.

To confirm the hunch, however, researchers at the University of Leicester conducted a series of tests, including extracting DNA from the teeth and a bone for comparison with Michael Ibsen, a modern-day descendant of Richard III's sister Anne of York.

Indeed, the researchers found the genetics matched up between Ibsen and that from the skeleton. "The DNA remains points to these being the remains of Richard III," University of Leicester genetics expert Turi King said during a press briefing.

The history of Richard III

Richard III was born in 1452 and ruled England from 1483 to 1485, a reign cut short by his death at the Battle of Bosworth Field, the decisive battle in the English civil war known as the War of the Roses.

Richard III's historical reputation is a twisted one, rife with accusations that he had his two young nephews murdered to secure his spot on the throne. The Shakespeare play "Richard III" cemented the king's villainous reputation about 100 years after the monarch died.

Read more at Discovery News

Women in Paris Can Now Wear Pants

We’ve come a long way, baby.

French officials have officially invalidated a 213-year-old order that forbade women in Paris from wearing pants. City chiefs had put the order in the books in 1800 requiring women seek permission from police if they wanted to “dress like a man.”

The order was issued on the heels of the French Revolution when working-class Parisian women were demanding the right to wear pants in their fight for equal rights.

Along the way, in 1892 and 1909, the order was somewhat loosened so that women who were riding a bicycle or a horse could wear pants. Today, Najat Vallaud-Belkacem, the minister for women’s rights, decreed in a statement that while the order had not been officially taken off the books, it has been made irrelevant by changes in French law.

“This order was aimed, first of all, at limiting the access of women to certain offices or occupations by preventing them from dressing in the manner of men,” she stated. “This order is incompatible with the principles of equality between women and men. From that incompatibility stems the implicit abrogation of the order.”

Read more at Discovery News

How Active Is the Brain in a Coma?

A new type of brain scan is giving neurologists insight into what is happening in the brains of patients who appear to be in comas.

When doctors recently tested former Israeli Prime Minister Ariel Sharon brain with a functional MRI, they found "robust" brain activity when he was shown pictures of his family and heard his son’s voice. A stroke and brain hemorrhage left Sharon in a coma seven years ago.

While the findings don’t change the prognosis of many patients, doctors are excited because the technology could foster a primitive form of communication with patients who are minimally conscious. It could also help prevent and correct misdiagnosis of patients who appear to be in comas, but are actually in a "locked-in" state.

"It’s like watching the top of the ocean and thinking you can understand what goes on under the waves," said Dr. Peter Nakaji, a neurosurgeon at the Barrow Neurological Institute in Phoenix, of the bedside techniques commonly used in clinics. He and others are hopeful that new techniques could provide a glimpse into the deeper realms of the brain.

The fMRI technology has been used in brain mapping research since the early 1990s, helping detect the onset of Alzheimer's and providing key information to brain surgeons about where to operate, but researchers in the United Kingdom and Belgium made a breakthrough discovery by applying the technology to patients who could not communicate at the bedside.

Knowing that 40 percent of patients with disorders of consciousness are misdiagnosed, the researchers designed an experiment to see if they could learn more about how their subjects’ brains were functioning. When 54 patients -- in vegetative or minimally conscious states  -- were asked to imagine hitting a tennis ball, the appropriate area lit up on the image of the brains of five of them. One of the patients was able to use the technique to answer yes or no questions. The study was published in The New England Journal of Medicine in 2010.

Read more at Discovery News

Feb 3, 2013

Synthetic Biology: Recreating Natural Complex Gene Regulation

By reproducing in the laboratory the complex interactions that cause human genes to turn on inside cells, Duke University bioengineers have created a system they believe can benefit gene therapy research and the burgeoning field of synthetic biology.

This new approach should help basic scientists as they tease out the effects of "turning on" or "turning off" many different genes, as well as clinicians seeking to develop new gene-based therapies for human disease.

"We know that human genes are not just turned on or off, but can be activated to any level over a wide range. Current engineered systems use one protein to control the levels of gene activation," said Charles Gersbach, assistant professor of biomedical engineering at Duke's Pratt School of Engineering and member of Duke's Institute for Genome Sciences and Policy. "However, we know that natural human genes are regulated by interactions between dozens of proteins that lead to diverse outcomes within a living system.

"In contrast to typical genetics studies that dissect natural gene networks in a top-down fashion, we developed a bottom-up approach, which allows us to artificially simulate these natural complex interactions between many proteins that regulate a single gene," Gersbach said. "Additionally, this approach allowed us to turn on genes inside cells to levels that were not previously possible."

The results of the Duke experiments, which were conducted by Pablo Perez-Pinera, a senior research scientist in Gersbach's laboratory, were published on-line in the journal Nature Methods. The research was supported by the National Institutes of Health, the National Science Foundation, The Hartwell Foundation, and the March of Dimes.

Human cells have about 20,000 genes which produce a multitude of proteins, many of which affect the actions of other genes. Being able to understand these interactions would greatly improve the ability of scientists in all areas of biomedical research. However because of the complexity of this natural system, synthetic biologists create simple gene networks to have precise control over each component. These scientists can use these networks for applications in biosensing, biocomputation, or regenerative medicine, or can use them as models to study the more complex natural systems.

"This new system can be a powerful new approach for probing the fundamental mechanisms of natural gene regulation that are currently poorly understood," Perez-Pinera said. "In this way, we can further the capacity of synthetic biology and biological programming in mammalian systems."

The latest discoveries were made possible by using a new technology for building synthetic proteins known as transcription activator-like effectors (TALEs), which are artificial enzymes that can be engineered to "bind" to almost any gene sequences. Since these TALEs can be easily produced, the researchers were able to make many of them to control specific genes.

Read more at Science Daily

Understanding Earth’s Climate Prior to the Industrial Era

Climate signals locked in the layers of glacial ice, preserved in the annual growth rings of trees, or fingerprinted in other so-called proxy archives such as lake sediments, speleothems, and corals allow researchers to quantify climate variation prior to instrumental measurements. An international research team has now investigated hundreds of these proxy records from across the globe and compared them with both simulations of the Earth’s climate and instrumental measurements of temperature and precipitation.

Climate extremes not always recognized in proxy archives

The scientists learned that these proxy archives provide an incomplete record of climate variation. The annual width or density of tree-rings is not only influenced by temperature while the ring is developing, but also from the climate of the past years and other factors like tree age. This makes it difficult to extract pure temperature signals from these natural archives. Importantly, the researchers found out that proxy data underestimate climate fluctuations of, for example, air temperature over the land surface where large year-to-year variability is common. In contrast, long-term trends in precipitation tend to be exaggerated by the proxy records. These findings indicate that the proxy data often result in a “blurry picture” of climate variation. The researchers were able to conclude from their work that short-term extreme climate events, such as individual years with hot summers, are not well captured by the proxy reconstructions.

Temperature trends can’t be used to understand rainfall

Investigations on the individual factors and processes fingerprinted in tree-ring, ice-core and speleothem records are needed to develop a more accurate history and understanding of the climate system. The authors explicitly warn that proxy records that predominately reflect temperature variation should not be used to make conclusions about precipitation change and vice-versa. "Our results point to uncertainties in the global climate system that were previously not recognized," says David Frank, co-author of this study. He continues: "This might be surprising because we know more about the Earth’s climate now than say 20-years ago. Part of the scientific process is to confront and uncover these unknowns while developing climate reconstructions." There is still a lot of basic research needed to reduce uncertainties about how the Earth’s climate system operated prior to the industrial era and how it may operate in the future.

From Science Daily