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Fireball 5

To find meteorites, listen to the legends of Australian aborigines

Henbury Meteorites Conservation Reserve
© Flickr user Matthias Siegel
One of the 4,700-year-old impact craters at Henbury Meteorites Conservation Reserve in Australia.
In the heart of Australia, at a remote site south of Alice Springs, the land is pitted with about a dozen strange depressions. Don't drink the rainwater that pools there, or a fire devil will fill you with iron.

So goes one Aboriginal tale that has been passed down across generations. The site is the Henbury meteorite field, which was created about 4,700 years ago when a large, iron-filled meteorite slammed into Earth's atmosphere and broke apart, scattering fragments. The Aboriginal warning is perhaps one of the clearest examples of an oral tradition that has preserved the memory of an ancient meteorite strike, argues Duane Hamacher at the University of New South Wales in Australia. According to Hamacher, such tales may be vital clues pointing toward future finds.

"These traditions could lead to the discovery of meteorites and impact sites previously unknown to Western science," he writes in a paper that will appear in an upcoming issue of Archaeoastronomy and that was published online August 27.

Most myths and tales are just stories passed down through the ages, altered over time like a vast game of "Telephone." But some are based on actual geological or astronomical events that occurred long ago. The search for the truth behind those stories has inspired a field of science called geomythology.
Battery

A solar cell that stores its own power: World's first 'solar battery' runs on light and air

solar battery
© Yiying Wu/The Ohio State University
Researchers at the Ohio State University have invented a solar battery -- a combination solar cell and battery -- which recharges itself using air and light.
Is it a solar cell? Or a rechargeable battery? Actually, the patent-pending device invented at The Ohio State University is both: the world's first solar battery.

In the October 3, 2014 issue of the journal Nature Communications, the researchers report that they've succeeded in combining a battery and a solar cell into one hybrid device.

Key to the innovation is a mesh solar panel, which allows air to enter the battery, and a special process for transferring electrons between the solar panel and the battery electrode. Inside the device, light and oxygen enable different parts of the chemical reactions that charge the battery.

The university will license the solar battery to industry, where Yiying Wu, professor of chemistry and biochemistry at Ohio State, says it will help tame the costs of renewable energy.

"The state of the art is to use a solar panel to capture the light, and then use a cheap battery to store the energy," Wu said. "We've integrated both functions into one device. Any time you can do that, you reduce cost."
Info

Thousands of seamounts discovered in new seafloor map

Seafloor map
© Live Science/Scripps Institution of Oceanography
The seafloor map revealed 15,000 new seamounts.
A new topographic map of Earth's mysterious ocean floor reveals thousands of towering volcanoes, hidden gashes where supercontinents ripped apart and other never-before-seen features once veiled by miles of water and thick sediment.

The topography of Earth's seafloor is as corrugated and bumpy as a book set in Braille. By reading these peaks and ridges, scientists can chronicle the birth of new ocean crust and the past wanderings of Earth's continents.

However, even though the seafloor carries the pivotal clues to plate tectonics, the dry surface of Mars has been detailed more clearly than the ocean's watery depths.

The new map, released today (Oct. 2) in the journal Science, promises to fill in some of the blanks. Compared with the previous map, from 1997, the resolution is twice as accurate overall and four times as better in coastal areas and the Arctic, said lead study author David Sandwell, a marine geophysicist at the Scripps Institution of Oceanography in La Jolla, California.
Bulb

Emergence: The remarkable simplicity of complexity

© Credit: Feliciano Guimarães/Flickr, CC BY
Patterns of emergence are all around us.
From the fractal patterns of snowflakes to cellular lifeforms, our universe is full of complex phenomena - but how does this complexity arise?

"Emergence" describes the ability of individual components of a large system to work together to give rise to dramatic and diverse behaviour.

Recent work by Enkeleida Lushi and colleagues from Brown University showed how bacteria in a drop of water spontaneously form a bi-directional vortex, with the bacteria near the centre of the droplet circulating in the opposite direction to those near the edge. Since the bacteria do not consciously decide to create the bi-directional vortex, such behaviour is said to be "emergent".

Unlike music from an orchestra led by the conductor, emergent behaviour arises spontaneously due to (often simple) interactions of the constituent parts with each other and the surrounding environment. Here, there is no "leader" deciding on the behaviour of the system.

© Credit: Christopher Porter/Flickr, CC BY-NC-ND
Magnify

Safer than silver: New antibacterial material made with algae


A close-up of the antibacterial fibre created by the KTH scientists. In this 2x2cm swatch of fabric are nearly 200,000 threads running in the same direction.
Consumers concerned about safety of silver ions in antibacterial and odor-free clothing will soon have a proven safe alternative thanks to ultra-thin thread and a substance found naturally in red algae.

The use of silver ions for antibacterial textiles has been a matter of hot debate worldwide. Sweden's national agency for chemical inspection is one authority which has ruled silver a health risk, citing possible damage to human genetic material, reproduction and embryonic development.

Mikael Hedenqvist, professor of polymer materials at KTH Royal Institute of Technology, says he and his colleagues, assistant professor Richard Olsson and doctoral student Rickard Andersson, have produced new antibacterial fibres that combine bio-compatible plastics with the antimicrobial compound, lanosol, which is commonly found in seaweeds of the family Rhodophyta, or red algae.

"The substance is a good alternative to particle-based antibacterials for clothing, as well as compresses or bandages," Hedenqvist says.

Using a process called electrospinning, they have succeeded in creating an ultra-thin thread, which means fabrics can have more contact between the antibacterial fibre and the surrounding area.

"Electrospinning produces quite thin thread, with a thickness on the order of one-hundreth of a human hair," Hedenqvist says. The result is more effective clean-up of bacteria.
Bug

Survival of the fittest group in spiders

Anelosimus studiosus spider
© Judy Gallagher
Tiny spiders may have a huge story to tell about evolution. UVM biologist Charles Goodnight helped University of Pittsburgh scientist Jonathan Pruitt unravel the tale. And from these spiders’ tangled webs, the researchers have uncovered the first-ever field-based evidence for a biological mechanism called “group selection.” Evolutionary theorists have been debating its existence and power for decades. Now Pruitt and Goodnight have observed it in the wild — as they report in the journal 'Nature.'
Along rivers in Tennessee and Georgia, scientists have been studying brownish-orange spiders, called Anelosimus studiosus, that make cobwebby nests "anywhere from the size of a golf ball to the size of a Volkswagen Beetle," researcher Jonathan Pruitt says. The individual spiders are only the size of a pencil eraser, but they form organized groups that can catch prey ranging from fruit flies to small vertebrates. "We have found carcasses of rats and birds inside their colonies," Pruitt says. Unlike most spiders, which are solitary, these social spiders work together in groups.

Now new research shows that they evolve together in groups, too.

Say "group selection" among some groups of evolutionary biologists and you won't be invited back to the party. But JonathanPruitt, at the University of Pittsburgh, and Charles Goodnight, at the University of Vermont, have been studying generations of these Anelosimus spiders - and have gathered the first-ever experimental evidence that group selection can fundamentally shape collective traits in wild populations.

Their results are presented in the Oct. 1 online edition of the journal Nature.

"Biologists have never shown an adaptation in nature which is clearly attributable to group selection," Goodnight said. "Our paper is that demonstration."
Info

Deep, hidden trench discovered beneath Antarctic glacier

Antarctica Trench
© Center for Remote Sensing of Ice Sheets
Radar that can penetrate ice helped researchers make this 3D map of a newly discovered trench beneath a glacier in Antarctica.
Ice-penetrating radar has uncovered a previously unknown ice-covered trench, and other detailed terrain, in the bedrock hidden beneath two massive, bluish glaciers in Greenland and Antarctica.

The gaping features were revealed in the first, highly detailed 3D maps of the frozen bedrock - the land under Greenland's Jakobshavn Glacier and Antarctica's Byrd Glacier - which may help researchers predict how glaciers, ice sheets and sea levels may change in the future.

"Without bed topography, you cannot build a decent ice-sheet model," lead researcher Prasad Gogineni, director of the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas, said in a statement.
Moon

Bizarre moon structures: How did they get there?

Topographic Moon
© Jay Dickson / Brown University
A topographic map of the moon (low elevations in purple, high in red) shows extensive lava flows in Oceanus Procellarum.
Even though its been more than four decades since humans first set foot on the moon, Earth's lone natural satellite still holds many mysteries.

"Virtually everyone who has ever lived has looked up at the moon; and many of us have wondered, 'How did those dark areas get there?'" says Maria Zuber, geophysics professor and vice president of research at the Massachusetts Institute of Technology in Cambridge.

Now, planetary geophysicists say they have finally unlocked the secrets of a mysterious dark patch known as the Oceanus Procellarum, or Ocean of Storms.

Scientists have previously speculated that the vast lunar depression may have been caused by an impact with an asteroid or comet. But now a new analysis of gravitational data gathered by NASA's GRAIL mission suggests that the ridges around the depression are more likely remnants of an "ancient magma plumbing system."

Planetary scientists have known for years that some of the dark splotches on the moon seen from Earth were likely carved by lava. That lava had to have come from the interior of the moon, but there was no explanation for how it found its way to the surface, until now. The answer, it seems, has to do with the moon's gravitational field.
Bug

Nature collides with James Bond: Newly discovered ant species hides in plain sight

James Bond Ants
© Dr. Scott Powell
Left: Crematogaster ampla; Right: Cephalotes specularis.
Researchers plan and plot every considerable aspect of their work, but sometimes it's something unexpected and seemingly insignificant that leads to the real discovery. That was the case for Scott Powell, assistant professor of biology at the George Washington University.

While conducting field research on turtle ants in the savannah region of Brazil, Dr. Powell noticed something peculiar: a species of ant infiltrating the region of a host ant, Crematogaster ampla. The C. ampla is known for its hyper-aggressiveness, but did not attack the invading species, which was Dr. Powell's first clue that something was amiss. The invading ant species acted very similarly to C. ampla but looked slightly different.

"I did a true double-take when I first saw this new species," said Dr. Powell. "As I turned away, after seeing what appeared to be large numbers of host foragers, it registered that a couple of the ants I had just laid eyes on were not quite like the others. Turning back around, I managed to re-find the few peculiar ants in the masses of host ants, and everything followed from there."
Key

Crypto Wars 2.0: New privacy battle looms after moves by Apple, Google


A new battle is brewing over privacy for mobile devices, after moves by Google and Apple to toughen the encryption of their mobile devices sparked complaints from law enforcement
A new battle is brewing over privacy for mobile devices, after moves by Google and Apple to toughen the encryption of their mobile devices sparked complaints from law enforcement.

The issue is part of a long-running debate over whether tech gadgets should have privacy-protecting encryption which makes it difficult for law enforcement to access in time-sensitive investigations.

FBI director James Comey reignited the issue last week, criticizing Apple and Google for new measures that keep smartphones locked down - without even the company holding the keys to unlock the data.

"What concerns me about this is companies marketing something expressly to allow people to place themselves beyond the law," the FBI chief said, warning that law enforcement may be denied timely access, even with a warrant, in cases ranging from child kidnapping to terrorism.

Former FBI criminal division chief Ronald Hosko made a similar point in an opinion piece in the Washington Post, citing a case in which the agency used smartphone data to solve a brutal kidnapping just in time to save the life of the victim.

"Most investigations don't rely solely on information from one source, even a smartphone," he said. "But without each and every important piece of the investigative puzzle, criminals and those who plan acts destructive to our national security may walk free."
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