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Monday, May 19, 2008

Wandering Poles Left Scars On Jupiter's Moon Europa: Could Life Exist Beneath Icy Crust?


Arc-shaped troughs (black and white arrows) extend 100s of kilometers on the surface of Jupiter's moon Europa. These enigmatic features are likely fractures resulting from a shift in Europa's spin axis. Vertical scale bar (right) is 100 km. (Credit: P. Schenk/NASA/LPI)

Washington, D.C.--Curved features on Jupiter's moon Europa may indicate that its poles have wandered by almost 90°, report scientists from the Carnegie Institution, Lunar and Planetary Institute, and University of California, Santa Cruz in the 15 May issue of Nature. Such an extreme shift suggests the existence of an internal liquid ocean beneath the icy crust, which could help build the case for Europa as possible habitat for extraterrestrial life.

The research team, which included Isamu Matsuyama of the Carnegie Institution's Department of Terrestrial Magnetism, used images from the Voyager, Galileo, and New Horizons spacecraft to map several large arc-shaped depressions that extend more than 500 kilometers across Europa's surface. With a radius of about 1500 kilometers, Europa is slightly smaller than the Earth's moon.

By comparing the pattern of the depressions with fractures that would result from stresses caused by a shift in Europa's rotational axis, the researchers determined that the axis had shifted by approximately 80°. The previous axis of rotation is now located about 10° from the present equator.

The drastic shift in Europa's rotational axis was likely a result of the build-up of thick ice at the poles. "A spinning body is most stable with its mass farthest from its spin axis," says Matsuyama. "On Europa, variations in the thickness of its outer shell caused a mass imbalance, so the rotation axis reoriented to a new stable state."

Such a change is called "true polar wander" as opposed to apparent polar wander caused by plate tectonics. There is evidence for true polar wander on Earth, and also on Mars and on Saturn's moon Enceladus. "Our study adds Europa to this list," says Matsuyama. "It suggests that planetary bodies might be more prone to reorientation than we thought."

The study also has implications for liquid water inside Europa. Scientists have hypothesized that Europa has an extensive subsurface ocean based on spacecraft photos that revealed its fractured, icy surface. The ocean beneath the crust would be kept liquid by heat generated by tidal forces from Jupiter's gravity. The presence of heat and water may make life possible, even though the subsurface ocean is cut off from solar energy.

"The large reorientation on Europa required to explain the circular depressions implies that its outer ice shell is decoupled from the core by a liquid layer," says Matsuyama. "Therefore, our study provides an independent test for the presence of an interior liquid layer."

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2008 May 18

On the Origin of Gold
Illustration Credit : Dana Berry, NASA

Explanation: Where did the gold in your jewelry originate? No one is completely sure. The relative average abundance in our Solar System appears higher than can be made in the early universe, in stars, and even in typical supernova explosions. Some astronomers have recently suggested that neutron-rich heavy elements such as gold might be most easily made in rare neutron-rich explosions such as the collision of neutron stars. Pictured above is an artist's illustration depicting two neutron stars spiraling in toward each other, just before they collide. Since neutron star collisions are also suggested as the origin of short duration gamma-ray bursts, it is possible that you already own a souvenir from one of the most powerful explosions in the universe.

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Don't flame me, bro'

Recently there has been a sharp increase in the amount of abusive language on the New Scientist website. No, it's not because our writers have become degenerates, it's because we rolled out a new commenting facility on all articles, giving people the chance to share their thoughts and opinions across the site.

I am particularly conscious of this trend because, as the moderator, I keep an eye on all comments and have to remove any that break our House Rules. This means I read a lot of comments (826 last week) and while most of them are perfectly polite, there's a stubborn minority that are rude, intentionally provocative, or just plain abusive. It seems people will say things online that they would never say face-to-face.

My pet theory about why people behave so rudely is that online commenting is treated, by most people, like a pub conversation ??? they don't necessarily expect to be taken seriously and the social rules are fairly relaxed. And yet, because comments appear in cold text without important cues like friendly body language, they can easily seem more offensive than if they would otherwise. As a result some people get annoyed, and the flaming and trolling begin.

After being described a few weeks ago as "a self-lobotomised liberal who can't face the facts", I decided to look into the psychology of online behaviour a bit further. Much of the research on online communication has looked at email, but it seems that many of the results can be generalised to apply to chat rooms and forums too.

Social psychologists have known for decades that, if we reduce our sense of our own identity ??? a process called deindividuation ??? we are less likely to stick to social norms. For example, in the 1960s Leon Mann studied a nasty phenomenon called "suicide baiting" ??? when someone threatening to jump from a high building is encouraged to do so by bystanders. Mann found that people were more likely to do this if they were part of a large crowd, if the jumper was above the 7th floor, and if it was dark. These are all factors that allowed the observers to lose their own individuality.

Social psychologist Nicholas Epley argues that much the same thing happens with online communication such as email. Psychologically, we are "distant" from the person we're talking to and less focused on our own identity. As a result we're more prone to aggressive behaviour, he says.

Another factor influencing online communication, according to Epley, is simply the risk of miscommunication involved with text-based messages, which are inherently more ambiguous. At the same time, he notes, email "has the feel of informality ??? we just fire something off", even though we probably ought to treat it with the same care as a written letter. And, as most people probably know, this can cause problems for both the sender and the receiver.

Epley explains further: "If I send a joke in an email, it'll be ambiguous when it gets to you. That's hard for me to detect: the joke is funny, and I use that knowledge to judge how you'll interpret it." But the receiver may not realise that the email is meant as a joke ??? particularly if they are in a bad mood to start with ??? and that can lead to horrified responses like "I can't believe you just said that" and to an unnecessary argument.

In 2005, Epley showed that people can vastly overestimate their ability to communicate unambiguously by email. He suggests that we find it hard to take another person's perspective when communicating electronically. Similarly, a forthcoming study by Kristin Byron found that people tend to interpret emails more negatively than other forms of communication (Academy of Management Review, volume 33, issue 2), making them even more likely to respond aggressively.

Another obvious factor is that, if you insult someone online, it's unlikely you'll face any physical retaliation for it. Epley compares the resulting psychological distance to being isolated inside a car ??? another situation that seems to make people more prone to abusiveness.

I'm not sure what we can do to minimise miscommunication and abuse online. But being aware that we're not as good at communication online as we'd like to think seems like a good start. I know I often have to restrain myself from joining in.

Michael Marshall, online editorial assistant
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Peter Thiel Makes Down Payment on Libertarian Ocean Colonies


An artist's conception of what a large seastead based on the spur design could look like. The Seasteading Institute envisions vast clumps of these structures forming city-states in the open ocean.
Illustration: Valdemar Duran

Tired of the United States and the other 190-odd nations on Earth?

If a small team of Silicon Valley millionaires get their way, in a few years, you could have a new option for global citizenship: A permanent, quasi-sovereign nation floating in international waters.

With a $500,000 donation from PayPal founder Peter Thiel, a Google engineer and a former Sun Microsystems programmer have launched The Seasteading Institute, an organization dedicated to creating experimental ocean communities "with diverse social, political, and legal systems."

"Decades from now, those looking back at the start of the century will understand that Seasteading was an obvious step towards encouraging the development of more efficient, practical public-sector models around the world," Thiel said in a statement.

It might sound like the setting for the videogame Bioshock, but the institute isn't playing around: It plans to splash a prototype into the San Francisco Bay within the next two years, the first step toward establishing deep-water city-states, or what it calls "seasteads" -- homesteads on the high seas.

Within the pantheon of would-be utopian communities, there's a particularly rich history of people trying to live outside the nation-state paradigm out in the ocean. The most ambitious was Marshall Savage's Aquarius Project, which aimed at nothing less than the colonization of the universe. There was also Las Vegas millionaire Michael Oliver's attempt to create a new island country, the Republic of Minerva, by dredging the shallow waters near Tonga. And the Freedom Ship was to be a mile-long portable country costing about $10 billion to construct.

None of these projects has succeeded, a fact that The Seasteading Institute's founders, Google's Patri Friedman and the semi-retired Wayne Gramlich, are keenly aware of throughout the 300-page book they've written about seasteading.

Instead of starting with a grand scheme worthy of a James Bond villain, the Institute is bringing an entrepreneurial, DIY mentality to creating oceanic city-states.

"There's a history of a lot of crazy people trying this sort of thing, and the idea is to do it in a way that's not crazy," said Joe Lonsdale, the institute's chairman and a principal at Clarium Capital Management, a multibillion-dollar hedge fund.

The seasteaders want to build their first prototype for a few million dollars, by scaling down and modifying an existing off-shore oil rig design known as a "spar platform."

This schematic illustrates the ballasting system that Wayne Gramlich imagines would keep the seastead from tipping over. The amount of water in the ballasts could be raised or lowered to move the seastead up and down.

Holl Liou/Wired.com

In essence, the seastead would consist of a reinforced concrete tube with external ballasts at the bottom that could be filled with air or water to raise or lower the living platform on top.

The spar design helps offshore platforms better withstand the onslaught of powerful ocean waves by minimizing the amount of structure that is exposed to their energy.

"You have very little cross-sectional interaction with waves [with] the spar design," Gramlich said.

The primary living space, about 300 square feet per person, would be inside the tube, but the duo envisions the top platform holding buildings, gardens, solar panels, wind turbines and (of course) satellites for internet access.

To some extent, they believe the outfittings for the seastead will be dependent on the business model, say aquaculture or tourism, that will support it and the number of people aboard.

"We're not trying to pick the one strategy because we think there will be multiple people who want one for multiple reasons," Gramlich said.

Dan Donovan, a long-time spokesman for Dominion, an energy company that operated Gulf of Mexico-based gas rigs, including Devils Tower, the world's deepest spar structure, said the group's plan wasn't too far-fetched. His company's off-shore rigs, which are much larger than the institute's planned seasteads, provided long-term housing for its workers.

"They were sort of like mobile homes. We could move them from one place to another," Donovan said. "People did live on them."

But even the institute members admit that their plans aren't far enough along to stand up to rigorous engineering scrutiny. Some engineers, Gramlich said, have been skeptical of their plan, particularly their desire to do it on the cheap.

"We have some legitimate doubting Thomases out there," Gramlich said.

But if the idea turns out to be just crazy enough that it works, Friedman, following in the footsteps of his grandfather, the Nobel Prize-winning economist Milton Friedman, envisions transforming the way that government functions.

"My dad and grandfather were happy arguing their ideas and were happy influencing people through the world of ideas," Friedman said. "I see a real need for people to go out and do something and show by example."

True to his libertarian leanings, Friedman looks at the situation in market terms: the institute's modular spar platforms, he argues, would allow for the creation of far cheaper new countries out on the high-seas, driving innovation.

"Government is an industry with a really high barrier to entry," he said. "You basically need to win an election or a revolution to try a new one. That's a ridiculous barrier to entry. And it's got enormous customer lock-in. People complain about their cellphone plans that are like two years, but think of the effort that it takes to change your citizenship."

Friedman estimates that it would cost a few hundred million dollars to build a seastead for a few thousand people. With costs that low, Friedman can see constellations of cities springing up, giving people a variety of governmental choices. If misguided policies arose, citizens could simply motor to a new nation.

"You can change your government without having to leave your house," he said.

Of course, one major role of government is to provide security, which would seem to be an issue on the open sea. But Friedman's not worried about defense beyond simple firearms because he thinks pirates will lack the financial incentive to attack the seasteads.

"More sophisticated pirates will take entire container ships that have tens of millions of dollars of cargo and 10 crew [members]," he said. "On a seastead, there's a much different crew-to-movable assets ratio."

In fact, his only worry is that a government will try to come calling and force their jurisdiction upon them. Toward that end, they are planning to fly a "flag of convenience" from a country that sells them, like Panama, to provide them with protection from national navies.

"If you're not flying a flag … any country can do whatever they want to you," he said.

Even if their big idea doesn't end up panning out, their story should live on in internet lore for confirming the dream that two guys with a blog and a love of Ayn Rand can land half a million dollars to pursue their dream, no matter how off-kilter or off-grid it might seem.

"Everything changed when we got the funding," Friedman said. "Before that, it was two guys with some ideas writing a book and blogging about their ideas.... Now that we've got some funding, it's something I plan to make a full-time job out of."

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10 Deepest Caves in the World

Image via Brian Masney

Long ago, our ancestors were using caves as shelter from wild animals and the forces of nature. Perhaps, this base necessity however, has always been eclipsed by man’s curiosity and desire to explore the mystical and enigmatic air inside the abyss. In the past, Environmental Graffiti has explored some amazing uses of caves – from discotheques, temples and underground cities to hotels and primary schools. That’s only scratching at the surface however. Today, with all sorts of equipment, caving has turned into something of an extreme sport - it involves climbing, crawling and sometimes even swimming. Looking at the most extreme end then, what about those caves that create the enigma, that fuel the stuff of legends; caves that appear bottomless and that seem to extend to the very center of the earth? What are the ten deepest caves on our planet?

10. Cehi 2

Slovenia’s deepest cave was mapped by Italian explorers from the Club Alpino Italiano of Trieste. They published a very interesting document, called Progressione 50: although it’s in Italian, you can see how the expedition went inside the Cehi 2 (or Ceki 2). The cave, which is in the Canin Massif, is located in the Western Julian Alps, on the Italian-Slovenian border. The alpinists managed to go as deep as 4928 feet (1502 m). To put this in perspective, the depth is over twice the height of the tallest man-made structure in the world.

Image via 1, 2

9. Sima de la Cornisa - Torca Magali

This is a caving system in the Picos de Europa mountains in Spain. An international team of speleologists including Valencian Silvino Villa and the Belgian Jan Masschelein explored the cave last summer and managed to go down, in what they call a “bottomless pit”, to 4944 feet (1507 m).

Image via 1

8. Shakta Vjacheslav Pantjukhina

As you notice from the next few items on the list, the Bzybsky Massif in Georgia is renowned and very rich in caves. More than 400 are present and just one of them that made it to our list of the deepest caves in the world is the Shakta Vjacheslav Pantjukhina. It’s 4948 feet (1508) m deep.

Image copyright 1

7. Sarma

The seventh deepest cave in the world is in the Caucuses range, in Abkhazia, Georgia and it goes down up to 5062 feet (1543 m). Speleologists that attended the expeditions from December 18, 2007 to January 12, 2008, mentioned that Sarma has the biggest potential to surpass Voronja and break the world record for being the deepest cave. They are still exploring the interior of this unfathomable enigma.

Images via 1

6. Torca del Cerro del Cuevon also known as T-33 and La Torca de las Saxifragas

Together, these two form the deepest cave in Spain. Located in the Picos de Europa mountains in the northern coast of the country, there are very few entrances to the cave, thus rendering it incredibly difficult to explore, so much so, that is considered to be the most technically difficult in the world. It took explorers 3 days to go to 5213 feet (1589 m) down.

Images via 1

5. Reseau Jean Bernard

Also known as the Gouffre Jean-Bernard or simply Jean Bernard, this is a 5256 feet (1602m) deep cave in the French Alps, in Samoëns. The cave has at least 8 entrances and was first discovered by the Groupe Vulcain back in 1959. Until 1980, it was considered to be the deepest cave in the world. Despite this, professional cavers consider the Jean Bernard not very interesting to climb.

Images via 1

4. Vogelshacht and Lamprechtsofen

A Polish Expedition (pdf link) connected the two caves: Vogelshacht and Lamprechtsofen, located in the Leoganger Steinberger area, in Salzburg, Austria. The cave system has so far been proven to be 5354 feet (1632 m) deep. Incredible really, that’s over a mile. Notwithstanding this, explorations continue, so this could be only the tip of the iceberg.

Images via 1, 2, 3

3. Gouffre Mirolda

From 9 to 12 January in 2003, an expedition exploring the Gouffre Mirolda cave in France, found that it was connected with the Lucien Coudlier, breaking the record for the world’s deepest cave . The cave measured 5685 feet (1733m) while the world record at the time was 5610 feet (Voronja cave). It was the first cave to be explored below 1 km. The record however, was beaten within a matter of years.

Images via 1, 2

2. Illuzia-Snezhnaja-Mezhonnogo

Two times larger than the world’s deepest cave, the Illuzia-Snezhnaja-Mezhonnogo cave is the second deepest in the world. Located on the Bzyb massif in Abkhazia, Georgia, the cave is renowned for being dangerous and very difficult to work in.

Images via 1

A team lead led by Aleksey Shelepin, in July 2007, came out with a very spectacular discovery giving birth to the cave system Illuzia-Sneznaja-Mezonnogo. Apparently there are two caves, Illuzia (Illusion) and Sneznaja (Snowy), that connect together and go down 5,751 feet (1,753 meters).

1. Krubera-Voronja Cave

Also known as the Cave of Kruber, Voronja is the deepest cave in the world with recent measurements extending to a total depth of 7188 feet (2191 m). It was the first cave to be explored to a depth of more than 2 km down.


Images via 1, 2, 3

On August 5th 2007, an international expedition with 56 members went in and the interesting thing is, they said that the cave system could be deeper. “The caving game is far from over. It won’t be; not as long as deeper abysses call out to be explored” said Alexander Klimchouk, a renowned speleologist.

The Crows’ Cave (that what it means) is located in Georgia in the Arabika Massif of the Gagra Range, near the coast of the Black Sea.

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$2 Billion Wind Turbine Order Is Largest Ever


Texas oilman T. Boone Pickens has placed an the largest ever order for wind turbines: he ordered 667 wind turbines from GE, each costing $3 million dollars, making the total order $2 billion. Pickens plans to develop the world’s largest wind farm in the panhandle of Texas.

The $2 billion order is just one quarter of the total amount he plans to purchase. Once built, the wind farm would have the capacity to supply power to over 1,200,000 homes in North Texas. Each turbine will produce 1.5 megawatts of electricity. The first phase of the project will produce 1,000 megawatts, enough energy to power 300,000 homes. GE will begin delivering the turbines in 2010, and current plans call for the project to start producing power in 2011.Ultimately, Picken’s company, Mesa Power, plans to have enough turbines to produce 4,000 megawatts of energy, the overall project is expected to cost $10 billion and be completed in 2014.

Mesa Power has leased sparsely populated land in the Texas panhandle, where the wind often blows during daylight hours when energy needs are highest. Texas’ Competitive Renewable Energy Zones (CREZ) transmission lines will deliver what Pickens hopes will be “cost effective and reliable electricity generated by renewable energy power projects.”
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Ireland to hunt nightmare fishing nets in north Atlantic

DUBLIN (AFP) - Ireland is to tackle the growing problem of so-called "ghost nets" that are destroying fish stocks in the northeast Atlantic Ocean, the Irish Sea Fisheries Board said Sunday.

The organisation said a series of pilot clean-up schemes, involving one Spanish and three Irish ships contracted to retrieve some of the thousands of kilometres of lost, dumped and abandoned nets, will run from June to September.

The scheme -- Operation Deepclean -- is being funded by the European Union at a cost of more than 500,000 euros (775,000 dollars) and will also seek to estimate the extent of the problem off the British and Irish coasts.

"The retrieval exercise will alleviate the problem of ghost fishing and help prevent further fish being caught in these nets," said Dominic Rihan, from the Irish Sea Fisheries Board.

"We also hope to get an estimate of the amount of lost nets in the particular areas."

"Ghost nets" are so called because they drift in the ocean after being abandoned or dumped and some have been found to be still catching fish and ensnaring other marine life for up to three years.

The fish are caught and die in the nets. The effect has been devastating with stocks of deepwater sharks falling to about 20 percent of original levels in less than 10 years.

It has been a growing environmental problem since the mid-1990s when a fleet of up to 50 vessels began gillnet fishing on the continental slopes in areas like Rockall and the Hatton Bank.

Most of the boats are based in Spain but registered in Britain, Germany and non-EU countries like Panama.

But although they seek to catch monkfish and deepwater shark, they also snare other species like halibut and ling.

No one is certain of just how many ghost nets there are either floating or fouling the seabed.

A joint Irish, Norwegian and British study from 2002 estimated that 1,254 kilometres (620 miles) of 600 by 50 metre (1,970 by 164 feet) sheets of nets were being lost every year but there was a reluctance to talk about the problem in the industry.

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