Swarm-mongering: Brainless blobs flock together

Birds of a feather flock together and now so do brainless, inanimate blobs. Made of microscopic particles, the artificial swarms could shed light on the mysterious mechanisms behind the natural swarming seen in fish and birds. They might also lead to materials with novel properties like self-healing.

Animals such as birds, fish and even humans that move together in swarms have individual intelligence, but Jérémie Palacci of New York University and colleagues wondered whether inanimate objects could also swarm. "From a physicist's point of view, if many different systems behave in the same way there must be an underlying physical rule," he says.

To explore this idea, the team created microscopic plastic spheres, each one with a cubic patch of haematite, an iron oxide, on its surface. When submerged in hydrogen peroxide, the spheres spread out in a disordered fashion. The team then shone blue light on the particles, causing the haematite cubes to catalyse the breakdown of any nearby hydrogen peroxide into water and oxygen. As hydrogen peroxide concentration dropped temporarily in these regions due to the reaction, osmotic forces cause more hydrogen peroxide to flow into them, and that in turn buffets the spheres. The whole process then repeats.

Self-healing swarm

When two spheres come close enough to each other, the balance of chemical forces shifts so that the two spheres are attracted. If there are enough spheres in the same place they will cluster together to form shapes of symmetrically arranged particles, which the team call crystals (see video, above). These crystals continue to be buffeted by the movement caused by the breakdown of hydrogen peroxide – but now they move together as one object, replicating a life-like swarm. Switch off the light, however, and the reaction stops, causing the crystal to lose the forces that hold it together, and the particle distribution becomes disordered once again.

"This system shows that even though the particles have no social interaction or intelligence, you can exhibit collective behaviour with no biology involved," says Palacci. Since the haematite is magnetic, it is even possible to steer the crystals in one direction by applying a magnetic field. Such control might be useful if the artificial swarms are to be harnessed for applications.

As the particles automatically fill any gaps that form in the crystal, again thanks to the chemical dynamics of the system, they could be used to create a self-assembling, self-healing material. The work is published in the journal Science today.

Schooled by fish

Iain Couzin of Princeton University says these kinds of systems are very useful for studying biological collective behaviour because researchers have complete control over their interactions – unlike natural systems.

His team has its own swarming experiment published in the same issue of Science, based on schools of fish that prefer to stay in shade. Their paper shows that shining a light on some of the fish in the school causes them to speed up, to get away from the light. But as a result, non-illuminated fish also speed up, even though, if acting purely as individuals, they would have had no reason to do so. "We show just by using simple interactions that schools can have a sense of responsiveness to the environment that individuals do not have," he says.

Couzin sees no reason why such behaviour should be limited to natural systems. "In future it may be possible to create systems of particles that can make collective decisions – something we often think of as only possible in biological systems," he says.

Journal references: Living crystals: Science, DOI: 10.1126/science.1230020; Fish: Science, DOI: 10.1126/science.1225883

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.

If you are having a technical problem posting a comment, please contact technical support.

Read More..

Sony invites press to mystery New York event

SAN FRANCISCO: Sony sent out invitations Thursday to a mystery event in New York City on February 20, sparking rumors that the world would get its first look at a new-generation PlayStation videogame console.

Both Sony and Microsoft are expected this year to show off successors to their competing consoles, which have been evolving into home entertainment hubs for films, television, music, social networking and more.

The PlayStation 3 was released in November 2006 and industry trackers believe a successor is on the near horizon.

In January, the number of PS3 units shipped by Sony hit an estimated 77 million units, according to market research firm International Data Corporation.

IDC gaming research manager Lewis Ward predicted at the time of the report that consoles will retain their strongholds in homes while expanding to include other digital entertainment.

"The console ecosystem is in a state of flux since these platforms need to support an ever-growing array of non-gaming features and services at the same time that game distribution and monetization is moving in a digital direction," Ward said.

"It doesn't appear that alternative platforms -- set-top boxes from cable companies, Web-connected smart TVs and so on -- are positioned to materially disrupt the trajectory of the 'big 3' console OEMs in 2013 or 2014."

Videogame industry sales should be bolstered by the arrival of next-generation videogame consoles from Sony and Microsoft, according to Ward.

"With the advent of eighth-generation consoles, starting with the Wii U, historical norms strongly imply that game disk revenue will stop bleeding in 2013 and rise substantively in 2014," he said in the report.

- AFP/ir

Read More..

Google reportedly gives EU antitrust probe settlement offer

Google was expected to submit a settlement proposal for the European Commission's antitrust inquiry by the end of January. And, it looks like the Web giant just made the deadline.

According to AllThingsD, sources familiar with the matter said that Google turned in a detailed proposal earlier today. However neither Google nor the EC are confirming whether a settlement proposal was definitively submitted.

When asked about the settlement offer, a Google spokesperson told CNET, "We continue to work cooperatively with the European Commission." The EC's press office has not yet responded to CNET's request for comment.

The EU's antitrust probe was opened in 2010 when European regulators asked the company to explain how it ranked search results and advertising after complaints of anticompetitive behavior from European businesses. Throughout the course of the inquiry, Google has been trying to settle. Google faces a fine of up to 10 percent of its global revenue, or about $4 billion, if the commission finds it has violated European antitrust laws.

This case mirrors a similar probe in the U.S. that was brought by the Federal Trade Commission and settled earlier this month. Under the FTC's settlement, a handful of companies may now choose to stop showing their results inside Google products like Google+ Local, Google Shopping, and Hotels. The search giant also agreed to voluntarily change the way it uses other Web sites' data.

Despite the EC and Google not being forthcoming about whether a settlement proposal was submitted today, inside sources did tell AllThingsD that the purported agreement looks very similar to the FTC's settlement. The main differences are that supposedly the EC agreement addresses better product labeling in search results but does not discuss patents.

Throughout both the U.S. and European Union probes, Google has denied any wrongdoing. In its agreement with the FTC, the company maintained its stance that it has done nothing wrong. According to AllThingsD, the EC settlement proposal will likely contain similar language.

Even if Google did submit a proposal today, it's still unclear whether the EC will accept it.

Read More..

Sinkhole Swallows Buildings in China

Photograph from AFP/Getty Images

The sinkhole that formed in the southern Chinese city of Guangzhou (pictured) is, unfortunately, not a new occurrence for the country.

Many areas of the world are susceptible to these sudden formations, including the U.S. Florida is especially prone, but Guatemala, Mexico, and the area surrounding the Dead Sea in the Middle East are also known for their impressive sinkholes. (See pictures of a sinkhole in Beijing that swallowed a truck.)

Published January 31, 2013

Read More..

Officials: Sen. Menendez Friend Raided in Medicare Fraud Investigation

Federal agents raided the West Palm Beach eye clinic of a longtime friend and political supporter of Sen. Robert Menendez earlier this week after a document shredding truck was observed at the building, following attempts by FBI agents to question Dr. Salomon Melgen about his relationship with the New Jersey Democrat, according to federal officials familiar with the investigation.

The execution of the search warrant was carried out by a federal health care task force, with agents from both the FBI and the federal Department of Health and Human Services Inspector General's office, which had been investigating suspected Medicare fraud by Melgen's clinics for more than a year, the sources told ABC News. The raid appeared unrelated to recent allegations regarding Menendez's trips to Melgen's home in the Dominican Republic.

An attorney for Dr. Melgen's office told ABC News that "the government has not informed Dr. Melgen what concerns it may have. We are confident that Dr. Melgen has acted appropriately at all times. "

A spokesperson for Sen. Menendez told ABC News Thursday that the Senator's office was unaware of any FBI investigation or inquiries involving the Senator. The spokesperson confirmed the Senator was a longtime friend of Dr. Melgen and had recently reimbursed Melgen $58,000 for three trips on the doctor's private jet to the Dominican Republic, following a complaint to the Senate Ethics Committee by a Samuel Thompson, a New Jersey state senator and chair of the Middlesex County Republican Organization, in November 2012, just days prior to Menendez's reelection.

The spokesperson said the Senator was advised by Democratic campaign finance attorneys that under the "friendship" exclusion he likely didn't need to reimburse the cost of the trips, but to avoid any questions of impropriety decided to repay the full cost.

The spokesperson for Menendez also strongly denied allegations by The Daily Caller website that Menendez was involved with underage prostitutes during those trips.

"All of these allegations from a right-wing blog of engaging in prostitution are absolutely false," said the spokesperson. "The Senator has known Dr. Melgen for years and his travel on Melgen's plane on three occasions has been reported and reimbursed as required by the rules."

A spokesperson for the FBI would not confirm or deny the existence of an investigation. The HHS did not immediately respond to a request for comment.

Melgen, an eye doctor, is a major political donor, with most of his money going to Democrats. Over the past two decades, he and his family have contributed more than $400,000, and nearly $50,000 has gone to Menendez and Menendez PACs. They also contributed $60,400 to the Democratic Senatorial Campaign Committee in 2009 – Menendez chaired the DSCC from 2009 to 2011 – and $50,000 to the New Jersey Democratic State Committee.

Questions about Menendez and his relationship with Melgen were raised by a pseudonymous tipster who contacted the Washington, D.C. good government group Citizens for Responsibility and Ethics in Washington (CREW) in 2012.

The tipster, using the name Peter Williams, told CREW via email that Menendez had traveled to the Dominican Republic in Melgen's plane and had had sex with prostitutes, at least one of them underage.

Read More..

Today on New Scientist: 30 January 2013

Timbuktu's precious scientific texts must be saved

Islamist militants in Mali have burned documents that attest to science in Africa before European colonisation - what remains must be protected

Think that massage feels good? Try adding drugs

Nerve bundles that respond to stroking have been identified and chemically activated in mice

How Obama will deliver his climate promise

The US is set to meet - and maybe exceed - Obama's pledge to cut US emissions by 17 per cent, which could give a boost to international climate talks

Minimum booze price will rein in alcohol abuse

Evidence suggests the UK government's proposal to set a minimum price for alcohol could save thousands of lives, and billions of pounds of public money

First real time-travel movies are loopers

Hollywood has played with time travel for decades, but now physicists have the first movies of what travelling to the past actually looks like

Surfer rides highest wave ever caught

Garret McNamara of Hawaii claims to have ridden the highest wave ever caught by a surfer, a 30-metre monster off the coast of Nazaré, Portugal

Infrared laptop trackpad ignores accidental touches

Longpad is a touchpad that extends the full width of your laptop and uses infrared sensors to ignore any unwanted touches

Close call coming: Averting the asteroid threat

With an errant space rock heading this way, just how good are our asteroid defences - and how do we avert the cataclysm?

The right to fight: women at war

The US military has accepted women into combat. What can science tell us about how women deal with being in the line of fire? And are they any different to men?

Earth and others lose status as Goldilocks worlds

Several planets are taking a hit thanks to a redefinition of the habitable zone - the area around a star in which liquid water can theoretically exist

The 10,000-year bender: Why humans love a tipple

Our taste for alcohol results from an evolutionary tussle between humans and yeast - one in which the microbes have often had the upper hand

Read More..

Japan PM says to change post-war constitution

TOKYO: Japan's hawkish Prime Minister Shinzo Abe told parliament Thursday that he intends to change the country's post-World War II constitution, lowering the bar for further amendments.

"I will start with amending Article 96 of the constitution, a move that many factions (inside his Liberal Democratic Party) support," Abe told upper house lawmakers, referring to the clause stipulating amendments require a two-thirds majority in parliament.

In the run-up to his landslide election victory in December, Abe said he wanted to study the possibility of altering the definition of Japan's armed forces contained in the document.

The country's well-funded and well-equipped military is referred to as the Self-Defence Forces, and barred from taking aggressive action. Its role is limited to defence of the nation.

Abe has said he would like to look into making the SDF into a full-fledged military, a plan that sets alarm bells ringing in Asian countries subject to Japan's sometimes-brutal occupation in the first half of the 20th century.

US occupying forces imposed the constitution in the aftermath of World War II, but its war-renouncing Article Nine is held dear by many Japanese.

-AFP/fl

Read More..

Foursquare reveals the 'best of' based on 3 billion check-ins

Want to know where to get the best Tex-Mex in Austin? Or how about the locals' favorite bookstore in San Francisco? Well, Foursquare will let you know what it thinks.

The check-in social network rolled out its "best of" guide today based on more than 3 billion member check-ins and tens of millions user tips, likes, and dislikes. The guide shows the top places that users checked into in 2012 in 30 cities across the U.S., such as New York, Atlanta, and Honolulu.

"There are plenty of lists of great places out there -- some are curated by editors, some by food critics, and others by people with really strong opinions about brisket," Foursquare wrote in a blog post today. "Here at Foursquare, our approach to figuring out the best places is a little different: we've analyzed our billions of check-ins and put together lists of places that people love most, based on where they've actually been."

The social network has more than 30 million members all of which have opinions and preferences for where they go drinking, which museums they frequent, and which parks are the best for relaxing.

"One of the things our data shows is how each city is unique," Foursquare wrote, "Bostonians love seafood, Portland is a veggie paradise, and Philly may be the city of brotherly love, but what they really love is a good sandwich."

By the way, according to Foursquare users, Chuy's is said to serve up Austin's best Tex-Mex and Green Apple Books is San Francisco's most beloved bookstore.

Foursquare is continuing to morph from a check-in social network into a more comprehensive location search engine -- putting it in direct competition with other recommendation and rating services, such as Yelp.

In November, the company launched its ten-point scoring system for local business and in October it launched its new Web site, which is open to non-members and has a prominent search box. Just yesterday, Foursquare rolled out its iPhone and Android apps for merchants, which let business owners more easily manage their presence on the social network.

Read More..

New Theory on How Homing Pigeons Find Home

Jane J. Lee

Homing pigeons (Columba livia) have been prized for their navigational abilities for thousands of years. They've served as messengers during war, as a means of long-distance communication, and as prized athletes in international races.

But there are places around the world that seem to confuse these birds—areas where they repeatedly vanish in the wrong direction or scatter on random headings rather than fly straight home, said Jon Hagstrum, a geophysicist who authored a study that may help researchers understand how homing pigeons navigate.

Hagstrum's paper, published online Wednesday in the Journal of Experimental Biology, proposes an intriguing theory for homing pigeon disorientation—that the birds are following ultralow frequency sounds back towards their lofts and that disruptions in their ability to "hear" home is what screws them up.

Called infrasound, these sound waves propagate at frequencies well below the range audible to people, but pigeons can pick them up, said Hagstrum, who works at the U.S. Geological Survey in Menlo Park, California.

"They're using sound to image the terrain [surrounding] their loft," he said. "It's like us visually recognizing our house using our eyes."

Homeward Bound?

For years, scientists have struggled to explain carrier pigeons' directional challenges in certain areas, known as release-site biases.

This "map" issue, or a pigeon's ability to tell where it is in relation to where it wants to go, is different from the bird's compass system, which tells it which direction it's headed in. (Learn about how other animals navigate.)

"We know a lot about pigeon compass systems, but what has been controversial, even to this day, has been their map [system]," said Cordula Mora, an animal behavior researcher at Bowling Green State University in Ohio who was not involved in the study.

Until now, the two main theories say that pigeons rely either on their sense of smell to find their way home or that they follow the Earth's magnetic field lines, she said.

If something screwed up their sense of smell or their ability to follow those fields, the thinking has been, that could explain why pigeons got lost in certain areas.

But neither explanation made sense to Hagstrum, a geologist who grew interested in pigeons after attending an undergraduate lecture by Cornell biologist William Keeton. Keeton, who studied homing pigeons' navigation abilities, described some release-site biases in his pigeons and Hagstrum was hooked.

"I was just stunned and amazed and fascinated," said Hagstrum. "I understand we don't get dark matter or quantum mechanics, but bird [navigation]?"

So Hagstrum decided to look at Keeton's pigeon release data from three sites in upstate New York. At Castor Hill and Jersey Hill, the birds would repeatedly fly in the wrong direction or head off randomly when trying to return to their loft at Cornell University, even though they had no problems at other locations. At a third site near the town of Weedsport, young pigeons would head off in a different direction from older birds.

There were also certain days when the Cornell pigeons could find their way back home from these areas without any problems.

At the same time, homing pigeons from other lofts released at Castor Hill, Jersey Hill, and near Weedsport, would fly home just fine.

Sound Shadows

Hagstrum knew that homing pigeons could hear sounds as low as 0.05 hertz, low enough to pick up infrasounds that were down around 0.1 or 0.2 hertz. So he decided to map out what these low-frequency sound waves would have looked like on an average day, and on the days when the pigeons could home correctly from Jersey Hill.

He found that due to atmospheric conditions and local terrain, Jersey Hill normally sits in a sound shadow in relation to the Cornell loft. Little to none of the infrasounds from the area around the loft reached Jersey Hill except on one day when changing wind patterns and temperature inversions permitted.

That happened to match a day when the Cornell pigeons had no problem returning home.

"I could see how the topography was affecting the sound and how the weather was affecting the sound [transmission]," Hagstrum said. "It started to explain all these mysteries."

The terrain between the loft and Jersey Hill, combined with normal atmospheric conditions, bounced infrasounds up and over these areas.

Some infrasound would still reach Castor Hill, but due to nearby hills and valleys, the sound waves approached from the west and southwest, even though the Cornell loft is situated south-southwest of Castor Hill.

Records show that younger, inexperienced pigeons released at Castor Hill would sometimes fly west while older birds headed southwest, presumably following infrasounds from their loft.

Hagstrum's model found that infrasound normally arrived at the Weedsport site from the south. But one day of abnormal weather conditions, combined with a local river valley, resulted in infrasound that arrived at Weedsport from the Cornell loft from the southeast.

Multiple Maps

"What [Hagstrum] has found for those areas are a possible explanation for the [pigeon] behavior at these sites," said Bowling Green State's Mora. But she cautions against extrapolating these results to all homing pigeons.

Some of Mora's work supports the theory that homing pigeons use magnetic field lines to find their way home.

What homing pigeons are using as their map probably depends on where they're raised, she said. "In some places it may be infrasound, and in other places [a sense of smell] may be the way to go."

Hagstrum's next steps are to figure out how large an area the pigeons are listening to. He's also talking to the Navy and Air Force, who are interested in his work. "Right now we use GPS to navigate," he said. But if those satellites were compromised, "we'd be out of luck." Pigeons navigate from point to point without any problems, he said.

Read More..

Former Police Captain Cleared of Ex-Wife's Murder

A former Ohio police captain has been cleared in the murder of his ex-wife and released from prison, where he had been for 15 years -- but prosecutors say they plan to appeal the ruling.

"I'm just a jumble of emotions and I just can't wait to hug all of my family," Douglas Prade told reporters outside the prison when he was released Tuesday afternoon, according to ABC News' Cleveland affiliate WEWS-TV.

He thanked "all of the people that supported me and communicated with me and told me to keep my spirits up."

Prade's ex-wife, Dr. Margo Prade, 41, was found shot to death in her minivan outside of her medical practice in November 1997.

Douglas Prade was an Akron, Ohio, police captain at the time.

At trial, he was convicted on murder and wiretapping charges and sentenced to life in prison.

Prade, now 66, maintained his innocence and, eventually, the Ohio Innocence Project took up his cause and petitioned for his release or a new trial based on new DNA testing.

One of the key factors in Prade's conviction was a bite mark found on Margo Prade's body. The prosecution brought in an expert that testified the bite mark came from Douglas Prade.

Phil Masturzo/Akron Beacon Journal/AP Photo

Marine Jon Hammar Released From Mexican Jail Watch Video

Man Escapes Jail 2nd Time by Impersonating Another Prisoner Set for Release Watch Video

Indiana Couple Rescues Deer, Faces Jail Time Watch Video

The Ohio Innocence Project commissioned a new DNA test that was not available at the time of the trial. The test found that the DNA around the bite was not Douglas Prade's.

Summit County Court of Common Pleas Judge Judy Hunter ruled that Prade should be set free because the new DNA results were "clear and convincing" in Prade's favor, according to the Associated Press.

Prosecutor Sherri Walsh is strongly disputing the new DNA evidence.

"This is a gross misapplication of the law, and we will be appealing Prade's exoneration. The defendant had to present new evidence so convincing that no juror would have found him guilty, and he failed to do so," Walsh said in a statement. "The DNA evidence presented by the Ohio Innocence Project on behalf of Prade is contaminated and unreliable. It does not prove innocence."

Walsh said that all evidence points to Prade as the person who killed Margo Prade.

"He was a serial stalker," Walsh said. "He tapped her phones and recorded more than 400 of her personal calls. He had verbally abused and threatened her. And we know Margo was afraid of him."

Other evidence includes Prade's handwritten tally of the bills he owed subtracted from the life insurance money he'd get if his wife died, Walsh said. Two witnesses placed him at the murder scene.

"We have not seen any credible evidence that suggests innocence, and we are taking all available actions to keep a dangerous killer off the streets," Walsh said.

Margo Prade's family is also upset by the decision.

"I feel like my life is in danger and my family's life is in danger now," Margo Prade's nephew Tony Fowler told the AP. "[Dr. Prade and her mother] are probably turning over in their graves but God will have the final say."

Alison McCarty, the former prosecutor on the case, told WEWS she respected the court's decision, but emphasized that the case is not yet closed.

"[Margo Prade] was such a superstar and it was just such a tremendous loss, and her death still needs justice," McCarty said.

The state has 30 days to file a motion in the court of appeals requesting permission to appeal the decision for a new trial.

Read More..