Science & Technology
Map


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."
Galaxy

Swift mission observes 'superflare' from a mini star

stellar flare
© Credit: NASA's Goddard Space Flight Center/S. Wiessinger
DG CVn, a binary consisting of two red dwarf stars shown here in an artist's rendering, unleashed a series of powerful flares seen by NASA's Swift. At its peak, the initial flare was brighter in X-rays than the combined light from both stars at all wavelengths under typical conditions.
On April 23, NASA's Swift satellite detected the strongest, hottest, and longest-lasting sequence of stellar flares ever seen from a nearby red dwarf star. The initial blast from this record-setting series of explosions was as much as 10,000 times more powerful than the largest solar flare ever recorded.

"We used to think major flaring episodes from red dwarfs lasted no more than a day, but Swift detected at least seven powerful eruptions over a period of about two weeks," said Stephen Drake, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who gave a presentation on the "superflare" at the August meeting of the American Astronomical Society's High Energy Astrophysics Division. "This was a very complex event."

At its peak, the flare reached temperatures of 360 million degrees Fahrenheit (200 million Celsius), more than 12 times hotter than the center of the sun.

The "superflare" came from one of the stars in a close binary system known as DG Canum Venaticorum, or DG CVn for short, located about 60 light-years away. Both stars are dim red dwarfs with masses and sizes about one-third of our sun's. They orbit each other at about three times Earth's average distance from the sun, which is too close for Swift to determine which star erupted.
Comet 2

Follow-up of splitting event in Comet C/2011 J2

Comet C/2011 J2
© Remanzacco Observatory
CBET 3979, issued on 2014 September 19, announced that observations of comet C/2011 J2 (LINEAR) (by F. Manzini, V. Oldani, A. Dan and R. Behrend) on Aug. 27.95, 28.85, and 30.91 UT led to the detection of a second, fainter, nuclear condensation (from now on Component B) located 0".8 east and 7".5 north of the main, brighter nuclear condensation (component A).

For more info about comet C/2011 J2 please see our May 2011 post on this blog by clicking here.

Whilst working on a long term morphology study on comet C/2012 K1 with N. Samarasinha and B. Mueller using the 2-meter Liverpool Telescope, we were alerted of the fragmentation event in comet C/2011 J2 and so diverted the telescope to this comet for a few days.
Top