Stone Age Axe Found Deliberately Stuck Into Earth

Archaeologists in southern Denmark have unearthed a 5,500-year-old axe with the handle still attached. The axe was deliberately jammed into what used to be the seabed during the Stone Age.

The finding was made during an archaeological survey for the construction of the Femern Belt link, an immersed tunnel that will connect the German island of Fehmarn with the Danish island of Lolland. Earlier this month, the same dig yielded 5,000-year-old footprints.

“Axes are among the typical finds from the Stone Age, but in hafted form (attached to a handle), they are extremely rare,” Anne-Lotte Sjørup Mathiesen of the Museum Lolland-Falster, said in a statement.

The axe was found stuck 12 inches down into the seabed, along with other artifacts which include a paddle, two bows and some 14 axe shafts.

As a result of the particular conditions of the silted seabed, all items were extremely well preserved.

Intriguingly, the artifacts were purposely placed standing up vertically into the earth, suggesting they were part of a ritual deposit.

“The items clearly show that the population used the coast as an offering area,” Sjørup Mathiesen said.

Excavation at the site is ongoing. Archaeologists from Museum Lolland-Falster expect to find more artifacts and new clues about what kinds of Stone Age rituals took place in the area.

From Discovery News

Ancient Mythical Carvings Found in Silk Road Cemetery

A cemetery dating back roughly 1,700 years has been discovered along part of the Silk Road, a series of ancient trade routes that once connected China to the Roman Empire.

The cemetery was found in the city of Kucha, which is located in present-day northwest China. Ten tombs were excavated, seven of which turned out to be large brick structures.

One tomb, dubbed "M3," contained carvings of several mythical creatures, including four that represent different seasons and parts of the heavens: the White Tiger of the West, the Vermilion Bird of the South, the Black Turtle of the North and the Azure Dragon of the East.

The M3 tomb also "consists of a burial mound, ramp, sealed gate, tomb entrance, screen walls, passage, burial chamber and side chamber" the researchers wrote in a report published recently in the journal Chinese Cultural Relics.

The cemetery was first found in July 2007 and was excavated by the Xinjiang Institute of Cultural Relics and Archaeology, with assistance from local authorities. The research team, led by Zhiyong Yu, director of the Xinjiang Archaeological Institute, published the findings in Chinese in the journal Wenwu. The article was recently translated into English and published in the journal Chinese Cultural Relics.

The identity of the people buried in the cemetery is a mystery. The cemetery had been robbed in the past and no writing was found that indicates the names of those buried or their positions in life.

The seven large brick tombs were likely constructed for people of wealth, the researchers said.

But, when the skeletal remains were analyzed, the researchers found that the tombs had been reused multiple times. Some of the tombs contain more than 10 occupants, and the "repeated multiple burials warrant further study," the researchers wrote.

The excavators think the cemetery dates back around 1,700 years, to a time when Kucha was vital to controlling the Western Frontiers (Xiyu) of China. Since the Silk Road trade routes passed through the Western Frontiers, control of this key region was important to China’s rulers.

"In ancient times, Kucha was called Qiuci in Chinese literature. It was a powerful city-state in the oasis of the Western Frontiers" the researchers wrote.

Read more at Discovery News

Ancient Canyon Discovered Under a River in Tibet

We think of canyons as being carved by rivers, as the Colorado River did with the Grand Canyon, so this item is a little mind-boggling.

In a just-published article in the journal Science, researchers from the California Institute of Technology have discovered an vast ancient canyon that lies buried underneath a present-day river that cuts through the Himalayas in Tibet.

The ancient canyon is thousands of feet deep in places, and apparently was carved by a previous river 3 to 7 million years ago.

"I was extremely surprised when my colleagues, Jing Liu-Zeng and Dirk Scherler, showed me the evidence for this canyon in southern Tibet," Caltech geology professor Jean-Philippe Avouac said in a press release "When I first saw the data, I said, 'Wow!' It was amazing to see that the river once cut quite deeply into the Tibetan Plateau because it does not today."

The ancient river "existed in this location prior to about 3 million years ago, but at that time, it was not affected by the Himalayas. However, as the Indian and Eurasian plates continued to collide and the mountain range pushed northward, it began impinging upon the river. Suddenly, about 2 1/2 million years ago, a rapidly uplifting section of the mountain range got in the river's way, damming it, and the canyon subsequently filled with sediment.

The scientists analyzed core samples collected by the China Earthquake Administration, which were taken from five locations along the Yarlung Tsangpo River. They found that at several locations there were sedimentary conglomerates, rounded gravel and larger rocks cemented together, that are associated with flowing rivers, until a depth of 800 meters or so, where the record clearly indicated bedrock. This indicated that the river once carved deeply into the plateau.

The discovery may force geologists to rethink long-held assumptions about how the Himalayas' dramatic gorges formed.

From Discovery News

How the LHC Makes 'Interstellar' Physics Real

In the sci-fi adventure “Interstellar,” many mind-bending physics concepts were explored including, but not exclusive to, relativity, time dilation, multidimensional theory, black holes, worm holes, quantum gravity and love.

In a new video released by Large Hadron Collider (LHC) scientists based in the US, Ohio State University LHC physicist James Beacham explains how the world’s biggest and most powerful particle accelerator is on the trail of many of these ideas and how they could revolutionize how we see the Universe.

But the LHC probably won’t help us understand love. Because that’s an emotion.

If you’ve read my Discovery News review of “Interstellar” you’ll know that the movie annoyed me. Sure, it was a thrilling space epic with some really great attempts at bringing complex astrophysics to the big screen, but it had some frustrating science problems, cringe-worthy dialog and plot holes big enough you could reverse a Daedalus-sized starship through. It fell short of what it promised and dragged on for an hour longer than it should have, in my opinion.

Before I ignite another comment box flaming (as if I didn’t learn from the original comments, take a look, it’s impressive), I will say one thing for Christopher Nolan’s blockbuster: it put some pretty lofty astrophysical theories in front of a mainstream audience like no recent science fiction movie has been able to achieve. And that is a very cool opportunity for scientists to explain what is going on.

In Beacham’s excellent rundown of the physics of “Interstellar,” he discusses why gravity is such a big deal in the movie’s storyline and how high-energy collisions may help us glimpse into the extra dimensions that unfolded for Matthew McConaughey inside his supermassive black hole. Also, he explains why love probably isn’t a physical force and why Matt Damon’s character’s death was so awesome (and a high point in the movie, in my opinion).

Enjoy:

From Discovery News

Prolonged Marijuana Use Linked with Brain Changes

Using marijuana daily for four years or longer may be related to certain changes in the brain, according to new research.

In the study, researchers used magnetic resonance imaging (MRI) to examine the brains of 48 adults who were chronic marijuana users, meaning they used the drug at least three times a day. Researchers also looked at 62 people who didn't use marijuana.

The investigators found that the people who had been smoking marijuana daily for at least four years had a smaller volume of gray matter in a region called the orbitofrontal cortex, which is commonly associated with addiction.

These users also showed greater connectivity between different parts of the brain, compared with nonusers. (Connectivity is a measure of how well information travels between different parts of the brain.)

"We found that there … not only is a change in structure, but there also tends to be a change reflected in the connectivity," said study author Francesca Filbey, an associate professor in the School of Behavioral and Brain Sciences at the University of Texas at Dallas.

The lost brain volume could explain the increased connectivity found in marijuana users' brains, Filbey told Live Science. The brain's connectivity may increase "to compensate for the loss in grey matter volume in that region," she said.

But it also possible that these differences in connectivity and the size of the brain region were present in the people in the study before they started using marijuana, she noted.

"All we can say is that we do see these" differences in people who use marijuana, Filbey said.

Still, there is reason to think marijuana did cause the differences. "We also saw that the younger you are when you start using marijuana regularly, the greater the changes in the brain," she said. Interestingly, the increased connectivity was not seen in the people who had been using marijuana for six to 10 years, she noted.

The differences in the brains of the marijuana users may have something to do with THC (tetrahydrocannabinol), which is the main psychoactive chemical in marijuana. THC affects cannabinoid receptors in the brain, which are involved in regulating appetite, memory and mood, and the orbitofrontal cortex has many of those cannabinoid receptors, Filbey said.

"If someone smokes marijuana, this area is bound to be affected by it," she said.

The researchers suspect that the changes in the brain occur to adapt to the THC in a person's system, she said.

Read more at Discovery News

Ancient Egyptian Handbook of Spells Deciphered

Researchers have deciphered an ancient Egyptian handbook, revealing a series of invocations and spells.

Among other things, the "Handbook of Ritual Power," as researchers call the book, tells readers how to cast love spells, exorcise evil spirits and treat "black jaundice," a bacterial infection that is still around today and can be fatal.

The book is about 1,300 years old, and is written in Coptic, an Egyptian language. It is made of bound pages of parchment — a type of book that researchers call a codex.

"It is a complete 20-page parchment codex, containing the handbook of a ritual practitioner," write Malcolm Choat and Iain Gardner, who are professors in Australia at Macquarie University and the University of Sydney, respectively, in their book, "A Coptic Handbook of Ritual Power" (Brepols, 2014).

The ancient book "starts with a lengthy series of invocations that culminate with drawings and words of power," they write. "These are followed by a number of prescriptions or spells to cure possession by spirits and various ailments, or to bring success in love and business."

For instance, to subjugate someone, the codex says you have to say a magical formula over two nails, and then "drive them into his doorpost, one on the right side (and) one on the left."

The Sethians

Researchers believe that the codex may date to the 7th or 8th century. During this time, many Egyptians were Christian and the codex contains a number of invocations referencing Jesus.

However, some of the invocations seem more associated with a group that is sometimes called "Sethians." This group flourished in Egypt during the early centuries of Christianity and held Seth, the third son of Adam and Eve, in high regard. One invocation in the newly deciphered codex calls "Seth, Seth, the living Christ."

The opening of the codex refers to a divine figure named "Baktiotha" whose identity is a mystery, researchers say. The lines read, "I give thanks to you and I call upon you, the Baktiotha: The great one, who is very trustworthy; the one who is lord over the forty and the nine kinds of serpents," according to the translation.

"The Baktiotha is an ambivalent figure. He is a great power and a ruler of forces in the material realm," Choat and Gardner said at a conference, before their book on the codex was published.

Historical records indicate that church leaders regarded the Sethians as heretics and by the 7th century, the Sethians were either extinct or dying out.

This codex, with its mix of Sethian and Orthodox Christian invocations, may in fact be a transitional document, written before all Sethian invocations were purged from magical texts, the researchers said. They noted that there are other texts that are similar to the newly deciphered codex, but which contain more Orthodox Christian and fewer Sethian features.

The researchers believe that the invocations were originally separate from 27 of the spells in the codex, but later, the invocations and these spells were combined, to form a "single instrument of ritual power," Choat told Live Science in an email.

Who would have used it?

The identity of the person who used this codex is a mystery. The user of the codex would not necessarily have been a priest or monk.

"It is my sense that there were ritual practitioners outside the ranks of the clergy and monks, but exactly who they were is shielded from us by the fact that people didn't really want to be labeled as a "magician,'" Choat said.

Some of the language used in the codex suggests that it was written with a male user in mind, however, that "wouldn't have stopped a female ritual practitioner from using the text, of course," he said.

Read more at Discovery News

Robot Sub Finds Surprisingly Thick Antarctic Sea Ice

Antarctica's ice paradox has yet another puzzling layer. Not only is the amount of sea ice increasing each year, but an underwater robot now shows the ice is also much thicker than was previously thought, a new study reports.

The discovery adds to the ongoing mystery of Antarctica's expanding sea ice. According to climate models, the region's sea ice should be shrinking each year because of global warming. Instead, satellite observations show the ice is expanding, and the continent's sea ice has set new records for the past three winters. At the same time, Antarctica's ice sheet (the glacial ice on land) is melting and retreating.

Measuring sea ice thickness is a crucial step in understanding what's driving the growth of sea ice, said study co-author Ted Maksym, an oceanographer at the Woods Hole Oceanographic Institution in Massachusetts. Climate scientists need to know if the sea ice expansion also includes underwater thickening.

"If we don't know how much ice is there is, we can't validate the models we use to understand the global climate," Maksym told Live Science. "It looks like there are significant areas of thick ice that are probably not accounted for."

The findings were published today (Nov. 24) in the journal Nature Geoscience.

Like icebergs, much of Antarctica's floating sea ice is underwater, hidden from satellites that track seasonal sea ice. And it's difficult to take direct measurements from ships or drilling, because the thickest ice is also the hardest to reach, Maksym said.

The researchers were stuck aboard an icebreaker in 20-foot-thick (6 meters) pack ice for more than a week after taking advantage of a lead, or open water, that accessed thick ice, he said. "Obviously that carried some risk, and we were stuck until the wind changed direction again," he said.

Pinging the ice

Over the last four years, the international group of researchers has mapped the bottom of sea ice with an underwater robot, or autonomous underwater vehicle (AUV), during two research cruises offshore Antarctica. The AUV can swim to a depth of about 100 feet (30 m) and has upward-looking sonar to survey the bottom of the sea ice.

"With the AUV, you can get under ice that is either difficult to access or difficult to drill, and in each region, we found some really thick ice, thicker than had been measured anywhere else," Maksym said.

Almost all of the sea ice that forms during the Antarctic winter melts during the summer, so scientists had assumed most of the ice never grew very thick. Previous studies suggested the ice was usually 3 to 6 feet (1 to 2 m) thick, with a few rare spots reaching up to 16 feet (5 m) in thickness. For comparison, most of the Arctic sea ice is twice as thick (6 to 9 feet, or 2 to 3 m), with some regions covered with 12 to 15 feet (4 to 5 m) of ice.

The robot sub surveys, which were spot-checked by drilling and shipboard tests, suggest Antarctica's average ice thickness is considerably higher than previous estimates. On average, the thickness of the ice was 4.6 to 18 feet (1.4 to 5.5 m). In the three regions it surveyed, the robot sub found that deformed, thickened ice accounted for at least half of and as much as 76 percent of the total ice volume, the researchers report.

"Our study shows that we're probably missing some of this thick ice, and we need to try to account for that when we try to compare what we see in models and satellites to what we see in the field," Maksym said.

The thickest ice measured during the survey was about 65 feet (20 m) thick, in the Bellingshausen Sea, Maksym told Live Science. In the Weddell Sea, the maximum ice thickness hit more than 45 feet (14 m), and offshore of Wilkes Land, the ice was about 53 feet (16 m) thick.

Next steps

These thick, craggy floes likely wouldn't exist without the fierce winds that circle Antarctica from west to east, the researchers said. Winter storms bash up the ice, freezing and reforming the rubble into new, thicker ice. "It must have been crunched up a tremendous amount and [the floes] piled up on top of each other," Maksym said. "The ice can generate enormous amounts of force if you have these strong winds. [The wind] is like an accordion, stretching it out and squishing it back together again."

The researchers' next step is to measure how much of Antarctica's total sea ice this thick ice represents. Maksym said it could be a "reasonably significant area of the pack."

Read more at Discovery News

Why Dried Whiskey Under Microscope Looks Like Art

Dried whiskey at the bottom of a glass produces stunning images that closely resemble fine art paintings, shows new research that also helps explain how the patterns form.

The effect results from both the chemical composition of whiskey as well as fluid dynamics. The presentation “Painting Pictures with Whiskey,” explaining the phenomenon, took place today during the American Physical Society’s Division of Fluid Dynamics Meeting, held in San Francisco.

Phoenix-based professional photographer and artist Ernie Button has been creating photos of the patterns formed after letting a drop or two of whiskey coat and dry in the bottom of a glass.

“It’s infinitely fascinating to me that a seemingly clear liquid leaves a pattern with such clarity and rhythm after the liquid is gone,” Button said in a press release.

Curiosity compelled him to reach out to Howard Stone and his Complex Fluids Group at Princeton University’s Department of Mechanical and Aerospace Engineering for insight.

“My group focused on gaining a better understanding of the composition of whiskey, identifying the possible ‘suspended material,’ and doing controlled model experiments to understand possible shapes and forms of deposits during evaporation,” Stone explained.

To study the flow patterns and concentration in the solution, as well as the final dried deposits from suspended particles, a postdoctoral researcher in Stone’s lab, Hyoungsoo Kim Kim, and colleagues used video microscopy of drying droplets of actual whiskey and compared it to video microscopy of an alcohol-water solution representative of whiskey. Typical whiskies are 40 percent by volume ethanol (alcohol) and 60 percent by volume water.

They found that initially, the droplet of alcohol-water solution creates a complex mixing flow. Ethanol evaporates first, due to the lower vapor pressure compared to water. Once the ethanol vanishes, a radial pattern can be observed.

As the initial ethanol concentration increases, the mobility of the receding contact line is increased as well. At high ethanol concentrations, the contact line recedes and draws groups of particles along with it that are then deposited in ring-shaped patterns.

All demonstrate what is known as the Marangoni Effect, which is the mass transfer along an interface between two fluids (in this case, alcohol and water) due to surface tension.

“The alcohol-water solution shows circulation flow patterns (triggered by the Marangoni Effect), which occur during drying and influences patterns formed in evaporating whiskey solutions,” Kim noted. “Deposits in the actual whiskey come from a small amount of inherent raw materials present from the preparation process.”

Barrel aged whiskey, for example, might leave behind trace particles of oak or other woods.

Read more at Discovery News

How the hummingbird achieves its aerobatic feats

The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How do they do it?

Now, the most detailed, three-dimensional aerodynamic simulation of hummingbird flight conducted to date has definitively demonstrated that the hummingbird achieves its nimble aerobatic abilities through a unique set of aerodynamic forces that are more closely aligned to those found in flying insects than to other birds.

The new supercomputer simulation was produced by a pair of mechanical engineers at Vanderbilt University who teamed up with a biologist at the University of North Carolina at Chapel Hill. It is described in the article "Three-dimensional flow and lift characteristics of a hovering ruby-throated hummingbird" published this fall in the Journal of the Royal Society Interface.

For some time researchers have been aware of the similarities between hummingbird and insect flight, but some experts have supported an alternate model which proposed that hummingbird's wings have aerodynamic properties similar to helicopter blades. However, the new realistic simulation demonstrates that the tiny birds make use of unsteady airflow mechanisms, generating invisible vortices of air that produce the lift they need to hover and flit from flower to flower.

You might think that if the hummingbird simply beats its wings fast enough and hard enough it can push enough air downward to keep its small body afloat. But, according to the simulation, lift production is much trickier than that.

For example, as the bird pulls its wings forward and down, tiny vortices form over the leading and trailing edges and then merge into a single large vortex, forming a low-pressure area that provides lift. In addition, the tiny birds further enhance the amount of lift they produce by pitching up their wings (rotate them along the long axis) as they flap.

Hummingbirds perform another neat aerodynamic trick -- one that sets them apart from their larger feathered relatives. They not only generate positive lift on the downstroke, but they also generate lift on the upstroke by inverting their wings. As the leading edge begins moving backwards, the wing beneath it rotates around so the top of the wing becomes the bottom and bottom becomes the top. This allows the wing to form a leading edge vortex as it moves backward generating positive lift.

According to the simulation, the downstroke produces most of the thrust but that is only because the hummingbird puts more energy into it. The upstroke produces only 30 percent as much lift but it takes only 30 percent as much energy, making the upstroke equally as aerodynamically efficient as the more powerful downstroke.

Large birds, by contrast, generate almost all of their lift on the downstroke. They pull in their wings toward their bodies to reduce the amount of negative lift they produce while flapping upward.

Although hummingbirds are much larger than flying insects and stir up the air more violently as they move, the way that they fly is more closely related to insects than it is to other birds, according to the researchers.

Insects like dragonflies, houseflies and mosquitoes can also hover and dart forward and back and side to side. Although the construction of their wings is much different, consisting of a thin membrane stiffened by a system of veins, they also make use of unsteady airflow mechanisms to generate vortices that produce the lift they need to fly. Their wings are also capable of producing positive lift on both upstroke and downstroke.

To capture the details of the aerodynamics of the hummingbird's ability to hover, Tyson Hedrick, associate professor of biology at UNC, put tiny dabs of non-toxic paint at nine places on a female ruby-throated hummingbird's wing. Then he took high-speed videos at 1,000 frames per second with four cameras while the bird hovered in front of an artificial flower.

Read more at Science Daily

Nail stem cells prove more versatile than press-ons

There are plenty of body parts that don't grow back when you lose them. Nails are an exception, and a new study published in The Proceedings of the National Academy of Sciences (PNAS) reveals some of the reasons why.

A team of USC Stem Cell researchers led by principal investigator Krzysztof Kobielak and co-first authors Yvonne Leung and Eve Kandyba has identified a new population of nail stem cells, which have the ability to either self-renew or undergo specialization or differentiation into multiple tissues.

To find these elusive stem cells, the team used a sophisticated system to attach fluorescent proteins and other visible "labels" to mouse nail cells. Many of these cells repeatedly divided, diluting the fluorescence and labels among their increasingly dim progeny. However, a few cells located in the soft tissue attached to the base of the nail retained strong fluorescence and labels because they either did not divide or divided slowly -- a known property of many stem cells.

The researchers then discovered that these slow-dividing stem cells have the flexibility to perform dual roles. Under normal circumstances, the stem cells contribute to the growth of both the nails and the adjacent skin. However, if the nail is injured or lost, a protein called "Bone Morphogenic Protein," or BMP, signals to the stem cells to shift their function exclusively to nail repair.

The researchers are now wondering whether or not the right signals or environmental cues could induce these nail stem cells to generate additional types of tissue -- potentially aiding in the repair of everything from nail and finger defects to severe skin injuries and amputations.

"That was very surprising discovery, since the dual characteristic of these nail stem cells to regenerate both the nail and skin under certain physiological conditions is quite unique and different from other skin stem cells, such as those of the hair follicle or sweat gland," said Kobielak.

From Science Daily