Jumat, 31 Mei 2013
Senin, 27 Mei 2013
Mexican Cave Art Offers Peek into Pre-Spanish Past
In the mountains of northeastern Mexico, archaeologists have unearthed thousands of ancient paintings on the walls of caves and ravines from a time before Spanish rule.
The rock art offers rare evidence from native cultures living in the area around the Sierra de San Carlos, a mountain range in Mexico's state of Tamaulipas, researchers say.
Almost 5,000 of these paintings were found across 11 different sites in the region, the researchers said. Created with red, yellow, black and white pigments, the images show animals from deer to lizards to centipedes, as well as people. Depictions of tents, hunting, fishing and possibly astronomical charts also offer a glimpse into the life of this mysterious culture.
The findings document the presence of pre-Hispanic groups, "where before it was said that there was nothing, when in fact it was inhabited by one or more cultures," archaeologist Gustavo Ramirez, of the Mexican National Institute of Anthropology and History, said in a statement.
The ancient people who once inhabited the mountains of Tamaulipas left very little behind for modern archaeologists to pore over. There is little known of their languages, rituals and customs, besides references to them by conquistadors and friars who colonized and Christianized the region.
Another archaeologist, Martha Garcia Sanchez, said these people were able to resist Spanish rule by living in the mountains, "where they had water, plants and animals to feed themselves."
The rock art was rediscovered in 2006, and archaeologists first started studying the site two years ago. Researchers have not yet been able to precisely date the paintings but further testing on samples of the pigments could reveal the age of the rock art.
"We have not found any ancient objects linked to the context, and because the paintings are on ravine walls and in the rainy season the sediments are washed away, all we have is gravel," said Ramirez.
The findings were presented during the Second Conference of Archaeological History in Mexico City.
Follow Megan Gannon on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.
Gallery: Europe's Oldest Rock Art Amazing Caves: Pictures of the Earth's Innards In Photos: Enormous Ancient Mexican Temple Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
The rock art offers rare evidence from native cultures living in the area around the Sierra de San Carlos, a mountain range in Mexico's state of Tamaulipas, researchers say.
Almost 5,000 of these paintings were found across 11 different sites in the region, the researchers said. Created with red, yellow, black and white pigments, the images show animals from deer to lizards to centipedes, as well as people. Depictions of tents, hunting, fishing and possibly astronomical charts also offer a glimpse into the life of this mysterious culture.
The findings document the presence of pre-Hispanic groups, "where before it was said that there was nothing, when in fact it was inhabited by one or more cultures," archaeologist Gustavo Ramirez, of the Mexican National Institute of Anthropology and History, said in a statement.
The ancient people who once inhabited the mountains of Tamaulipas left very little behind for modern archaeologists to pore over. There is little known of their languages, rituals and customs, besides references to them by conquistadors and friars who colonized and Christianized the region.
Another archaeologist, Martha Garcia Sanchez, said these people were able to resist Spanish rule by living in the mountains, "where they had water, plants and animals to feed themselves."
The rock art was rediscovered in 2006, and archaeologists first started studying the site two years ago. Researchers have not yet been able to precisely date the paintings but further testing on samples of the pigments could reveal the age of the rock art.
"We have not found any ancient objects linked to the context, and because the paintings are on ravine walls and in the rainy season the sediments are washed away, all we have is gravel," said Ramirez.
The findings were presented during the Second Conference of Archaeological History in Mexico City.
Follow Megan Gannon on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.
Gallery: Europe's Oldest Rock Art Amazing Caves: Pictures of the Earth's Innards In Photos: Enormous Ancient Mexican Temple Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Ohio man, 87, skydives to aid sick great-grandson
WAYNESVILLE, Ohio (AP) An 87-year-old World War II veteran has parachuted from a plane in an Ohio to support his ailing great-grandson.
Clarence Turner of Fairfield made the jump Saturday with an instructor. He says he wanted to generate attention for the plight of 10-month-old Julian Couch, who suffers from a lung disease that could require a transplant.
WLWT of Cincinnati reports that (http://bit.ly/14RYHF1) Julian is hospitalized in Columbus. A fundraiser is planned for June 2.
Turner also made a jump at age 85 to fulfill a goal to experience freefalling and landing as he did in the Army. He served from 1944-47, and his last jump was in Japan.
Turner says he also hopes to someday make a parachute jump at an older age than former President George H.W. Bush, who's 88.
Spin Zone: Physicists Get 1st Look at Strange Quantum Magnetism
Using super-chilled atoms, physicists have for the first time observed a weird phenomenon called quantum magnetism, which describes the behavior of single atoms as they act like tiny bar magnets.
Quantum magnetism is a bit different from classical magnetism, the kind you see when you stick a magnet to a fridge, because individual atoms have a quality called spin, which is quantized, or in discrete states (usually called up or down). Seeing the behavior of individual atoms has been hard to do, though, because it required cooling atoms to extremely cold temperatures and finding a way to "trap" them.
The new finding, detailed in the May 24 issue of the journal Science, also opens the door to better understanding physical phenomena, such as superconductivity, which seems to be connected to the collective quantum properties of some materials. [Twisted Physics: 7 Mind-Blowing Findings]
Spin science
The research team at the Swiss Federal Institute of Technology (ETH) in Zurich focused on atoms' spin, because that's what makes magnets magnetic all the spins of the atoms in a bar magnet are pointed the same way.
To get a clear view of atoms' spin behaviors, the researchers had to cool potassium atoms to near absolute zero. That way, the random thermal "noise" basically background radiation and heat didn't spoil the view by jostling the potassium atoms around.
The scientists then created an "optical lattice" a crisscrossing set of laser beams. The beams interfere with each other and create regions of high and low potential energy. Neutral atoms with no charge will tend to sit in the lattice's "wells," which are regions of low energy.
Once the lattice is built, the atoms will sometimes randomly "tunnel" through the sides of the wells, because the quantum nature of particles allows them to be in multiple places at the same time, or to have varying amounts of energy. [Quantum Physics: The Coolest Little Particles in Nature]
Another factor that determines where the atoms lie in the optical lattice is their up or down spin. Two atoms can't be in the same well if their spins are the same. That means atoms will have a tendency to tunnel into wells with others that have opposite spins. After a while, a line of atoms should spontaneously organize itself, with the spins in a non-random pattern. This kind of behavior is different from materials in the macroscopic world, whose orientations can have a wide range of in-between values; this behavior is also why most things aren't magnets the spins of the electrons in the atoms are oriented randomly and cancel each other out.
And that's exactly what the researchers found. The spins of atoms do organize, at least on the scale the experiment examined.
"The question is, what are the magnetic properties of these one-dimensional chains?" said Tilman Esslinger, a professor of physics at ETH whose lab did the experiments. "Do I have materials with these properties? How can these properties be useful?"
Quantum magnetism
This experiment opens up possibilities for increasing the number of atoms in a lattice, and even creating two-dimensional, gridlike arrangements of atoms, and possibly triangular lattices as well.
One debate among experts is whether at larger scales the spontaneous ordering of atoms would happen in the same way. A random pattern would mean that in a block of iron atoms, for instance, one is just as likely to see a spin up or down atom in any direction. The spin states are in what is called a "spin liquid" a mishmash of states. But it could be that atoms spontaneously arrange themselves at larger scales.
"They've put the foundation on various theoretical matters," said Jong Han, a professor of condensed matter physics theory at the State University of New York at Buffalo, who was not involved in the research. "They don't really establish the long-range order, rather they wanted to establish that they have observed a local magnetic order."
Whether the order the scientists found extends to larger scales is an important question, because magnetism itself arises from the spins of atoms when they all line up. Usually those spins are randomly aligned. But at very low temperatures and small scales, that changes, and such quantum magnets behave differently.
Han noted that such lattices, especially configurations where the potential wells connect to three others, rather than two or four, would be especially interesting. Esslinger's lab showed that atoms tend to jump to potential wells where the spins are opposite; but if the wells are arranged so that the atom can jump to two other atoms, it can't "choose" which well to go to because one of the two atoms will always be in the same spin state.
Esslinger said his lab wants to try building two-dimensional lattices and explore that very question. "What happens to magnetism if I change the geometry? It's no longer clear if spins should be up or down."
Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.
The 9 Biggest Unsolved Mysteries in Physics Gallery: Dreamy Images Reveal Beauty in Physics What's That? Your Physics Questions Answered Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Quantum magnetism is a bit different from classical magnetism, the kind you see when you stick a magnet to a fridge, because individual atoms have a quality called spin, which is quantized, or in discrete states (usually called up or down). Seeing the behavior of individual atoms has been hard to do, though, because it required cooling atoms to extremely cold temperatures and finding a way to "trap" them.
The new finding, detailed in the May 24 issue of the journal Science, also opens the door to better understanding physical phenomena, such as superconductivity, which seems to be connected to the collective quantum properties of some materials. [Twisted Physics: 7 Mind-Blowing Findings]
Spin science
The research team at the Swiss Federal Institute of Technology (ETH) in Zurich focused on atoms' spin, because that's what makes magnets magnetic all the spins of the atoms in a bar magnet are pointed the same way.
To get a clear view of atoms' spin behaviors, the researchers had to cool potassium atoms to near absolute zero. That way, the random thermal "noise" basically background radiation and heat didn't spoil the view by jostling the potassium atoms around.
The scientists then created an "optical lattice" a crisscrossing set of laser beams. The beams interfere with each other and create regions of high and low potential energy. Neutral atoms with no charge will tend to sit in the lattice's "wells," which are regions of low energy.
Once the lattice is built, the atoms will sometimes randomly "tunnel" through the sides of the wells, because the quantum nature of particles allows them to be in multiple places at the same time, or to have varying amounts of energy. [Quantum Physics: The Coolest Little Particles in Nature]
Another factor that determines where the atoms lie in the optical lattice is their up or down spin. Two atoms can't be in the same well if their spins are the same. That means atoms will have a tendency to tunnel into wells with others that have opposite spins. After a while, a line of atoms should spontaneously organize itself, with the spins in a non-random pattern. This kind of behavior is different from materials in the macroscopic world, whose orientations can have a wide range of in-between values; this behavior is also why most things aren't magnets the spins of the electrons in the atoms are oriented randomly and cancel each other out.
And that's exactly what the researchers found. The spins of atoms do organize, at least on the scale the experiment examined.
"The question is, what are the magnetic properties of these one-dimensional chains?" said Tilman Esslinger, a professor of physics at ETH whose lab did the experiments. "Do I have materials with these properties? How can these properties be useful?"
Quantum magnetism
This experiment opens up possibilities for increasing the number of atoms in a lattice, and even creating two-dimensional, gridlike arrangements of atoms, and possibly triangular lattices as well.
One debate among experts is whether at larger scales the spontaneous ordering of atoms would happen in the same way. A random pattern would mean that in a block of iron atoms, for instance, one is just as likely to see a spin up or down atom in any direction. The spin states are in what is called a "spin liquid" a mishmash of states. But it could be that atoms spontaneously arrange themselves at larger scales.
"They've put the foundation on various theoretical matters," said Jong Han, a professor of condensed matter physics theory at the State University of New York at Buffalo, who was not involved in the research. "They don't really establish the long-range order, rather they wanted to establish that they have observed a local magnetic order."
Whether the order the scientists found extends to larger scales is an important question, because magnetism itself arises from the spins of atoms when they all line up. Usually those spins are randomly aligned. But at very low temperatures and small scales, that changes, and such quantum magnets behave differently.
Han noted that such lattices, especially configurations where the potential wells connect to three others, rather than two or four, would be especially interesting. Esslinger's lab showed that atoms tend to jump to potential wells where the spins are opposite; but if the wells are arranged so that the atom can jump to two other atoms, it can't "choose" which well to go to because one of the two atoms will always be in the same spin state.
Esslinger said his lab wants to try building two-dimensional lattices and explore that very question. "What happens to magnetism if I change the geometry? It's no longer clear if spins should be up or down."
Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.
The 9 Biggest Unsolved Mysteries in Physics Gallery: Dreamy Images Reveal Beauty in Physics What's That? Your Physics Questions Answered Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Minggu, 26 Mei 2013
Asian stocks still shaky as Nikkei slides 3 percent
By Ian Chua
SYDNEY (Reuters) - Japan's Nikkei index slid 3.0 percent in early trade on Monday, following on from a 3.5 percent slide last week in breath-taking volatility that no doubt left many investors shaken.
"Last week's shock will probably last throughout this week," said Kenichi Hirano, a strategist at Tachibana Securities. "But the Japanese market's fundamentals in the mid-to-long term have not changed, so there still is upside in the longer term."
Other Asian stock markets got off to a cautious start on Monday, having suffered their biggest weekly drop in around a year as investors fretted about the possibility of the Federal Reserve dialing down its stimulus program as well as a slowing Chinese economy.
MSCI's broadest index of Asia-Pacific shares outside Japan edged down 0.3 percent. It skidded 2.6 percent last week to one-month lows, posting its biggest fall since May 2012.
Australia's S&P/ASX 200 index slipped 0.5 percent, but South Korea's KOSPI managed to eke out a 0.1 percent gain.
"Markets are starting to price the removal of unprecedented policy stimulus provided by the Federal Reserve following the global financial crisis," analysts at Barclays Capital wrote in a note.
"Investors have faced this situation several times in recent years, but... the edginess of markets to ebbs and flows in the data and Fed communications in recent months suggests this time is different. Market movements are saying the Fed's exit is now more 'when' than 'if'."
Supporting the view that the Fed may soon scale down its massive stimulus program, data on Friday showed orders for US-made durable goods rose more than expected in April, a hopeful sign that a sharp slowdown in factory output could soon run its course.
That should be music to the ears of dollar bulls. Indeed, figures on Friday showed currency speculators increased bets in favor of the greenback to the highest since at least June 2008.
The dollar index, which tracks the greenback's performance against a currency basket, hit a three-year high last week before succumbing to a bit of pressure. It was last down 0.1 percent at 83.633 .
Much of the excitement in currency markets last week centered on the yen as turbulence in the Nikkei prompted investors to book profits on bearish yen positions.
That saw the dollar recoil from a 4-1/2 year high of 103.74 yen set on May 22. It was last down 0.1 percent at 101.13, not far off a two-week trough of 100.66 plumbed Friday.
Still, traders expect the yen's downtrend to remain intact after the Bank of Japan (BOJ) last month unleashed the world's most intense burst of stimulus.
On Sunday, Bank of Japan Governor Haruhiko Kuroda said the bank will be vigilant to any signs of overheating of asset prices or excessive risk-taking by financial institutions, adding that there were no signs of that now.
Commodity markets were subdued with UK and U.S. financial markets closed on Monday for public holidays. There is also little in the way of major economic news due out of Asia.
(Additional reporting by Ayai Tomisawa in Tokyo; Editing by Eric Meijer)
Sabtu, 25 Mei 2013
NYPD investigating actress Bynes allegations
NEW YORK (AP) Internal Affairs officers on Saturday were looking into allegations made by actress Amanda Bynes that New York Police Department officers sexually assaulted her when she was charged with heaving a marijuana bong out the window of her 36th-floor Manhattan apartment.
The 27-year-old former child star first alleged during her arraignment on Friday that police illegally entered her apartment after being called to her midtown building. But in a Twitter message believed to be from the troubled actress posted Saturday, Bynes alleged that her arresting officer also sexually assaulted her.
"As it would with any such allegation, regardless of its credibility, IAB is investigating it," said the NYPD's chief spokesman, Paul Browne, referring to the internal affairs bureau.
The Twitter handle used to make the sexual assault allegations Saturday does not appear to be verified by the social network but Bynes' friend, former Hollywood publicist Jonathan Jaxson, said Saturday the tweet was made from Bynes' account. Twitter did not immediately return a request for comment.
In court on Friday, the former "Hairspray" star made no mention of the sexual assault allegations, though she did complain of illegal entry to her apartment. She's been charged with reckless endangerment, attempted tampering with evidence and unlawful possession of marijuana.
A law enforcement official who spoke to the Associated Press on the condition of anonymity because of an ongoing investigation said the building manager was with officers at Bynes' apartment when they arrived Thursday night. The official said officers were kept waiting approximately five minutes before she opened the door to them. The same official said the building manager told internal affair investigators nothing untoward happened.
Bynes was released by Chief New York County Judge Neil Ross on her own recognizance because, Ross said, he did not believe her to be a flight risk. But in releasing her, Ross also issued a stern warning to Bynes, telling her not to get rearrested or miss any court dates. She's due back in court on July 9.
Attempts to reach Bynes' arraignment lawyer were unsuccessful Saturday evening.
Bynes rose to fame starring in Nickelodeon's "All That" and has also starred in several films, including 2010's "Easy A." But she has been in the news more recently because of several scrapes with the law and bizarre public behavior.
Bynes was arrested Thursday night after building officials called police to complain she was rolling a joint and smoking pot in the lobby. The officers went to her apartment where they saw heavy smoke and a bong sitting on the kitchen counter. They said she tossed the bong out the window in front of them, prosecutors said Friday.
__
Associated Press writer Colleen Long contributed to this report.
Search for pilot in deadly NY Angel Flight ongoing
EPHRATAH, N.Y. (AP) The search for the pilot of a volunteer Angel Flight that crashed in upstate New York, killing at least two people, ended unsuccessfully Saturday, a town official said.
Town of Ephratah County Board Supervisor Todd Bradt said rescue workers will resume their efforts Sunday to find the third person who was aboard the twin-engine plane that crashed Friday evening in Ephratah, about an hour west of Albany.
He said divers would go back into a large pond where much of the small plane has been submerged, using sonar because visibility is so bad.
"It's so muddy and murky, they can't see nothing," Bradt said. He said a piece of the plane was removed from the pond Saturday but wasn't sure which piece or how much is still under water.
Fulton County Sheriff Thomas Lorey has said the flight's two passengers were found dead Friday near where the twin-engine plane crashed in a wooded area and that the bulk of the plane was found submerged in a pond.
Lorey did not return messages seeking comment Saturday.
Angel Flight is a nonprofit group that arranges free air transportation for sick patients from volunteer pilots. Larry Camerlin, president and founder of Angel Flight Northeast, said the organization was "tremendously saddened" by news of the crash.
The twin-engine Piper PA 34 had departed from Hanscom Field in Bedford, Mass., and was headed to Rome, N.Y., before it crashed just after 5 p.m., Federal Aviation Administration spokeswoman Kathleen Bergen said.
Officials haven't yet identified the passengers or pilot.
Witnesses described the destruction that started in the air above Ephratah, a sleepy town of about 700 people.
The parking lot of Granny's Ice Cream Shanty, which is less than a mile from the crash site, was filled with emergency vehicles Saturday morning. Owner Joan Dudley told The Associated Press that she and her employees were among the first at the scene Friday night.
"We were just leaving to get something to eat, and we heard this noise," Dudley said.
"We looked up and saw the plane flipping in the air. Then it fell apart," she said. "Parts and pieces of it were flying through the sky, and a body fell out."
They called 911 as they parked their car and ran to the crash site in the rain to see if they could rescue anyone.
"Airplane parts were all over the place," she said. "They were picking them up all over last night."
Ephratah resident Roger Berry, 75, said he was outside chopping wood when the plane crashed.
"When I heard it, I knew something was wrong," Berry said. "It made one circle and came back around."
Berry said he heard a bang, then saw pieces of the plane fall out of the air. Although most of the plane landed in the pond, Berry said pieces, including the engine, scattered about the area.
"My neighbor, she was sleeping in her bedroom," Berry said. "The motor fell 50 feet from her bedroom."
Berry said he ran home to get his raincoat, then assisted rescuers by directing traffic.
The FAA and the National Transportation Safety Board are investigating what might have caused the crash.
Visibility at the time in Rome was 10 miles, said National Weather Service meteorologist Brian Montgomery. It was slightly raining with winds of 13 to 14 mph.
Angel Flight Northeast said it has set up free air transportation and medical care for more than 65,000 children and adults on about 60,000 flights covering more than 12 million miles. It was founded in 1996.
"We all offer our thoughts and prayers to the families of those affected," Camerlin said in a statement. "Our volunteer pilots are the most compassionate and generous individuals who donate their time, aircraft and fuel to transport patients and loved ones for free to essential medical care that would otherwise not be readily available to them. There are no words that can adequately express our sorrow."
Town of Ephratah County Board Supervisor Todd Bradt said rescue workers will resume their efforts Sunday to find the third person who was aboard the twin-engine plane that crashed Friday evening in Ephratah, about an hour west of Albany.
He said divers would go back into a large pond where much of the small plane has been submerged, using sonar because visibility is so bad.
"It's so muddy and murky, they can't see nothing," Bradt said. He said a piece of the plane was removed from the pond Saturday but wasn't sure which piece or how much is still under water.
Fulton County Sheriff Thomas Lorey has said the flight's two passengers were found dead Friday near where the twin-engine plane crashed in a wooded area and that the bulk of the plane was found submerged in a pond.
Lorey did not return messages seeking comment Saturday.
Angel Flight is a nonprofit group that arranges free air transportation for sick patients from volunteer pilots. Larry Camerlin, president and founder of Angel Flight Northeast, said the organization was "tremendously saddened" by news of the crash.
The twin-engine Piper PA 34 had departed from Hanscom Field in Bedford, Mass., and was headed to Rome, N.Y., before it crashed just after 5 p.m., Federal Aviation Administration spokeswoman Kathleen Bergen said.
Officials haven't yet identified the passengers or pilot.
Witnesses described the destruction that started in the air above Ephratah, a sleepy town of about 700 people.
The parking lot of Granny's Ice Cream Shanty, which is less than a mile from the crash site, was filled with emergency vehicles Saturday morning. Owner Joan Dudley told The Associated Press that she and her employees were among the first at the scene Friday night.
"We were just leaving to get something to eat, and we heard this noise," Dudley said.
"We looked up and saw the plane flipping in the air. Then it fell apart," she said. "Parts and pieces of it were flying through the sky, and a body fell out."
They called 911 as they parked their car and ran to the crash site in the rain to see if they could rescue anyone.
"Airplane parts were all over the place," she said. "They were picking them up all over last night."
Ephratah resident Roger Berry, 75, said he was outside chopping wood when the plane crashed.
"When I heard it, I knew something was wrong," Berry said. "It made one circle and came back around."
Berry said he heard a bang, then saw pieces of the plane fall out of the air. Although most of the plane landed in the pond, Berry said pieces, including the engine, scattered about the area.
"My neighbor, she was sleeping in her bedroom," Berry said. "The motor fell 50 feet from her bedroom."
Berry said he ran home to get his raincoat, then assisted rescuers by directing traffic.
The FAA and the National Transportation Safety Board are investigating what might have caused the crash.
Visibility at the time in Rome was 10 miles, said National Weather Service meteorologist Brian Montgomery. It was slightly raining with winds of 13 to 14 mph.
Angel Flight Northeast said it has set up free air transportation and medical care for more than 65,000 children and adults on about 60,000 flights covering more than 12 million miles. It was founded in 1996.
"We all offer our thoughts and prayers to the families of those affected," Camerlin said in a statement. "Our volunteer pilots are the most compassionate and generous individuals who donate their time, aircraft and fuel to transport patients and loved ones for free to essential medical care that would otherwise not be readily available to them. There are no words that can adequately express our sorrow."
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