Supernova explosion created in lab

LONDON: Scientists have used laser beams 60,000 billion times more powerful than a laser pointer to recreate scaled supernova explosions in the laboratory to investigate one of the most energetic events in the Universe.

Supernova explosions, triggered when the fuel within a star reignites or its core collapses, launch a detonation shock wave that sweeps through a few light years of space from the exploding star in just a few hundred years.

To investigate what may cause these peculiar shapes, an international team led by Oxford University scientists has devised a method of studying supernova explosions in the laboratory instead of observing them in space.

"It may sound surprising that a table-top laboratory experiment that fits inside an average room can be used to study astrophysical objects that are light years across," said professor Gianluca Gregori of Oxford's department of Physics.

"In reality, the laws of physics are the same everywhere, and physical processes can be scaled from one to the other in the same way that waves in a bucket are comparable to waves in the ocean. So our experiments can complement observations of events such as the Cassiopeia A supernova explosion," said Gregori, who led the study.

The Cassiopeia A supernova explosion was first spotted about 300 years ago in the Cassiopeia constellation 11,000 light years away, its light has taken this long to reach us.

The optical images of the explosion show irregular 'knotty' features and associated with these are intense radio and X-ray emissions.

Whilst no one is sure what creates these phenomena one possibility is that the blast passes through a region of space that is filled with dense clumps or clouds of gas.

"Our team began by focusing three laser beams onto a carbon rod target, not much thicker than a strand of hair, in a low density gas-filled chamber," said Jena Meinecke an Oxford graduate student, who headed the experiment.

The enormous amount of heat generated more than a few million degrees celsius by the laser caused the rod to explode creating a blast that expanded out through low density gas.

In the experiments the dense gas clumps or gas clouds that surround an exploding star were simulated by introducing a plastic grid to disturb the shock front.

"The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent just like the images from Cassiopeia," said Gregori.

"We found that the magnetic field is higher with the grid than without it. Since higher magnetic fields imply a more efficient generation of radio and X-ray photons, this result confirms that the idea that supernova explosions expand into uniformly distributed interstellar material isn't always correct and it is consistent with both observations and numerical models of a shock-wave passing through a 'clumpy' medium," said Gregory.

The research was published in the journal Nature Physics.

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30% of world is now fat, no country immune: Study

LONDON: Almost a third of the world is now fat, and no country has been able to curb obesity rates in the last three decades, according to a new global analysis.

Researchers found more than 2 billion people worldwide are now overweight or obese. The highest rates were in the Middle East and North Africa, where nearly 60 percent of men and 65 percent of women are heavy. The U.S. has about 13 percent of the world's fat population, a greater percentage than any other country. China and India combined have about 15 percent.

"It's pretty grim," said Christopher Murray of the Institute for Health Metrics and Evaluation at the University of Washington, who led the study. He and colleagues reviewed more than 1,700 studies covering 188 countries from 1980 to 2013. "When we realized that not a single country has had a significant decline in obesity, that tells you how hard a challenge this is."

Murray said there was a strong link between income and obesity; as people get richer, their waistlines also tend to start bulging. He said scientists have noticed accompanying spikes in diabetes and that rates of cancers linked to weight, like pancreatic cancer, are also rising.

The new report was paid for by the Bill & Melinda Gates Foundation and published online Thursday in the journal, Lancet.

Last week, the World Health Organization established a high-level commission tasked with ending childhood obesity.

"Our children are getting fatter," Dr. Margaret Chan, WHO's director-general, said bluntly during a speech at the agency's annual meeting in Geneva. "Parts of the world are quite literally eating themselves to death." Earlier this year, WHO said that no more than 5 percent of your daily calories should come from sugar.

"Modernization has not been good for health," said Syed Shah, an obesity expert at United Arab Emirates University, who found obesity rates have jumped five times in the last 20 years even in a handful of remote Himalayan villages in Pakistan. His research was presented this week at a conference in Bulgaria. "Years ago, people had to walk for hours if they wanted to make a phone call," he said. "Now everyone has a cellphone."

Shah also said the villagers no longer have to rely on their own farms for food.
"There are roads for (companies) to bring in their processed foods and the people don't have to slaughter their own animals for meat and oil," he said. "No one knew about Coke and Pepsi 20 years ago. Now it's everywhere."

In Britain, the independent health watchdog issued new advice on Wednesday recommending heavy people be sent to free weight-loss classes to drop about 3 percent of their weight, reasoning that losing just a few pounds improves health and is more realistic. About two in three adults in the U.K. are overweight, making it the fattest country in Western Europe.

"This is not something where you can just wake up one morning and say, `I am going to lose 10 pounds,'" said Mike Kelly, the agency's public health director, in a statement. "It takes resolve and it takes encouragement."

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The moon's internet speed soon to be faster than earth

LONDON: The internet speed on the moon will soon be faster than that on earth. Scientists have found a way to get broadband speed of just under 20 megabits per second (mbps) on the Moon.

A team of researchers from the Massachusetts Institute of Technology's (MIT) Lincoln Laboratory working with Nasa recently demonstrated the data communication technology which makes it possible to receive large amounts of data and stream video and audio from the moon to earth and vice versa.

A download speed of 19.44mbps was achieved through a laser-powered communication uplink through RF signals, along with an upload speed of 622mbps - that is 4,800 times faster than the previous record.

This download speed is more than six times faster than the download speed achieved by the best radio system ever flown to the moon, and the Nasa's Lunar Laser Communication Demonstration (LLCD) laser space terminal is half the weight and uses 25% less power than the radio system.

LLCD also demonstrated a data upload speed of 20 mbps on a laser beam transmitted from a ground station in New Mexico to the Lunar Atmosphere and Dust Environment Explorer spacecraft in orbit; this speed is 5000 times faster than the upload speed of the best radio system flown to the moon.

"This will be the first time that we present both the implementation overview and how well it actually worked," said Mark Stevens of MIT Lincoln Laboratory. "The on-orbit performance was excellent and close to what we'd predicted, giving us confidence that we have a good understanding of the underlying physics," he added.

22.10 | 0 komentar | Read More

30% of world is now fat, no country immune: Study

LONDON: Almost a third of the world is now fat, and no country has been able to curb obesity rates in the last three decades, according to a new global analysis.

Researchers found more than 2 billion people worldwide are now overweight or obese. The highest rates were in the Middle East and North Africa, where nearly 60 percent of men and 65 percent of women are heavy. The U.S. has about 13 percent of the world's fat population, a greater percentage than any other country. China and India combined have about 15 percent.

"It's pretty grim," said Christopher Murray of the Institute for Health Metrics and Evaluation at the University of Washington, who led the study. He and colleagues reviewed more than 1,700 studies covering 188 countries from 1980 to 2013. "When we realized that not a single country has had a significant decline in obesity, that tells you how hard a challenge this is."

Murray said there was a strong link between income and obesity; as people get richer, their waistlines also tend to start bulging. He said scientists have noticed accompanying spikes in diabetes and that rates of cancers linked to weight, like pancreatic cancer, are also rising.

The new report was paid for by the Bill & Melinda Gates Foundation and published online Thursday in the journal, Lancet.

Last week, the World Health Organization established a high-level commission tasked with ending childhood obesity.

"Our children are getting fatter," Dr. Margaret Chan, WHO's director-general, said bluntly during a speech at the agency's annual meeting in Geneva. "Parts of the world are quite literally eating themselves to death." Earlier this year, WHO said that no more than 5 percent of your daily calories should come from sugar.

"Modernization has not been good for health," said Syed Shah, an obesity expert at United Arab Emirates University, who found obesity rates have jumped five times in the last 20 years even in a handful of remote Himalayan villages in Pakistan. His research was presented this week at a conference in Bulgaria. "Years ago, people had to walk for hours if they wanted to make a phone call," he said. "Now everyone has a cellphone."

Shah also said the villagers no longer have to rely on their own farms for food.
"There are roads for (companies) to bring in their processed foods and the people don't have to slaughter their own animals for meat and oil," he said. "No one knew about Coke and Pepsi 20 years ago. Now it's everywhere."

In Britain, the independent health watchdog issued new advice on Wednesday recommending heavy people be sent to free weight-loss classes to drop about 3 percent of their weight, reasoning that losing just a few pounds improves health and is more realistic. About two in three adults in the U.K. are overweight, making it the fattest country in Western Europe.

"This is not something where you can just wake up one morning and say, `I am going to lose 10 pounds,'" said Mike Kelly, the agency's public health director, in a statement. "It takes resolve and it takes encouragement."

22.10 | 0 komentar | Read More

The moon's internet speed soon to be faster than earth

LONDON: The internet speed on the moon will soon be faster than that on earth. Scientists have found a way to get broadband speed of just under 20 megabits per second (mbps) on the Moon.

A team of researchers from the Massachusetts Institute of Technology's (MIT) Lincoln Laboratory working with Nasa recently demonstrated the data communication technology which makes it possible to receive large amounts of data and stream video and audio from the moon to earth and vice versa.

A download speed of 19.44mbps was achieved through a laser-powered communication uplink through RF signals, along with an upload speed of 622mbps - that is 4,800 times faster than the previous record.

This download speed is more than six times faster than the download speed achieved by the best radio system ever flown to the moon, and the Nasa's Lunar Laser Communication Demonstration (LLCD) laser space terminal is half the weight and uses 25% less power than the radio system.

LLCD also demonstrated a data upload speed of 20 mbps on a laser beam transmitted from a ground station in New Mexico to the Lunar Atmosphere and Dust Environment Explorer spacecraft in orbit; this speed is 5000 times faster than the upload speed of the best radio system flown to the moon.

"This will be the first time that we present both the implementation overview and how well it actually worked," said Mark Stevens of MIT Lincoln Laboratory. "The on-orbit performance was excellent and close to what we'd predicted, giving us confidence that we have a good understanding of the underlying physics," he added.

22.10 | 0 komentar | Read More

Supernova explosion created in lab

LONDON: Scientists have used laser beams 60,000 billion times more powerful than a laser pointer to recreate scaled supernova explosions in the laboratory to investigate one of the most energetic events in the Universe.

Supernova explosions, triggered when the fuel within a star reignites or its core collapses, launch a detonation shock wave that sweeps through a few light years of space from the exploding star in just a few hundred years.

To investigate what may cause these peculiar shapes, an international team led by Oxford University scientists has devised a method of studying supernova explosions in the laboratory instead of observing them in space.

"It may sound surprising that a table-top laboratory experiment that fits inside an average room can be used to study astrophysical objects that are light years across," said professor Gianluca Gregori of Oxford's department of Physics.

"In reality, the laws of physics are the same everywhere, and physical processes can be scaled from one to the other in the same way that waves in a bucket are comparable to waves in the ocean. So our experiments can complement observations of events such as the Cassiopeia A supernova explosion," said Gregori, who led the study.

The Cassiopeia A supernova explosion was first spotted about 300 years ago in the Cassiopeia constellation 11,000 light years away, its light has taken this long to reach us.

The optical images of the explosion show irregular 'knotty' features and associated with these are intense radio and X-ray emissions.

Whilst no one is sure what creates these phenomena one possibility is that the blast passes through a region of space that is filled with dense clumps or clouds of gas.

"Our team began by focusing three laser beams onto a carbon rod target, not much thicker than a strand of hair, in a low density gas-filled chamber," said Jena Meinecke an Oxford graduate student, who headed the experiment.

The enormous amount of heat generated more than a few million degrees celsius by the laser caused the rod to explode creating a blast that expanded out through low density gas.

In the experiments the dense gas clumps or gas clouds that surround an exploding star were simulated by introducing a plastic grid to disturb the shock front.

"The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent just like the images from Cassiopeia," said Gregori.

"We found that the magnetic field is higher with the grid than without it. Since higher magnetic fields imply a more efficient generation of radio and X-ray photons, this result confirms that the idea that supernova explosions expand into uniformly distributed interstellar material isn't always correct and it is consistent with both observations and numerical models of a shock-wave passing through a 'clumpy' medium," said Gregory.

The research was published in the journal Nature Physics.

22.10 | 0 komentar | Read More

30% of world is now fat, no country immune: Study

LONDON: Almost a third of the world is now fat, and no country has been able to curb obesity rates in the last three decades, according to a new global analysis.

Researchers found more than 2 billion people worldwide are now overweight or obese. The highest rates were in the Middle East and North Africa, where nearly 60 percent of men and 65 percent of women are heavy. The U.S. has about 13 percent of the world's fat population, a greater percentage than any other country. China and India combined have about 15 percent.

"It's pretty grim," said Christopher Murray of the Institute for Health Metrics and Evaluation at the University of Washington, who led the study. He and colleagues reviewed more than 1,700 studies covering 188 countries from 1980 to 2013. "When we realized that not a single country has had a significant decline in obesity, that tells you how hard a challenge this is."

Murray said there was a strong link between income and obesity; as people get richer, their waistlines also tend to start bulging. He said scientists have noticed accompanying spikes in diabetes and that rates of cancers linked to weight, like pancreatic cancer, are also rising.

The new report was paid for by the Bill & Melinda Gates Foundation and published online Thursday in the journal, Lancet.

Last week, the World Health Organization established a high-level commission tasked with ending childhood obesity.

"Our children are getting fatter," Dr. Margaret Chan, WHO's director-general, said bluntly during a speech at the agency's annual meeting in Geneva. "Parts of the world are quite literally eating themselves to death." Earlier this year, WHO said that no more than 5 percent of your daily calories should come from sugar.

"Modernization has not been good for health," said Syed Shah, an obesity expert at United Arab Emirates University, who found obesity rates have jumped five times in the last 20 years even in a handful of remote Himalayan villages in Pakistan. His research was presented this week at a conference in Bulgaria. "Years ago, people had to walk for hours if they wanted to make a phone call," he said. "Now everyone has a cellphone."

Shah also said the villagers no longer have to rely on their own farms for food.
"There are roads for (companies) to bring in their processed foods and the people don't have to slaughter their own animals for meat and oil," he said. "No one knew about Coke and Pepsi 20 years ago. Now it's everywhere."

In Britain, the independent health watchdog issued new advice on Wednesday recommending heavy people be sent to free weight-loss classes to drop about 3 percent of their weight, reasoning that losing just a few pounds improves health and is more realistic. About two in three adults in the U.K. are overweight, making it the fattest country in Western Europe.

"This is not something where you can just wake up one morning and say, `I am going to lose 10 pounds,'" said Mike Kelly, the agency's public health director, in a statement. "It takes resolve and it takes encouragement."

22.10 | 0 komentar | Read More

The moon's internet speed soon to be faster than earth

LONDON: The internet speed on the moon will soon be faster than that on earth. Scientists have found a way to get broadband speed of just under 20 megabits per second (mbps) on the Moon.

A team of researchers from the Massachusetts Institute of Technology's (MIT) Lincoln Laboratory working with Nasa recently demonstrated the data communication technology which makes it possible to receive large amounts of data and stream video and audio from the moon to earth and vice versa.

A download speed of 19.44mbps was achieved through a laser-powered communication uplink through RF signals, along with an upload speed of 622mbps - that is 4,800 times faster than the previous record.

This download speed is more than six times faster than the download speed achieved by the best radio system ever flown to the moon, and the Nasa's Lunar Laser Communication Demonstration (LLCD) laser space terminal is half the weight and uses 25% less power than the radio system.

LLCD also demonstrated a data upload speed of 20 mbps on a laser beam transmitted from a ground station in New Mexico to the Lunar Atmosphere and Dust Environment Explorer spacecraft in orbit; this speed is 5000 times faster than the upload speed of the best radio system flown to the moon.

"This will be the first time that we present both the implementation overview and how well it actually worked," said Mark Stevens of MIT Lincoln Laboratory. "The on-orbit performance was excellent and close to what we'd predicted, giving us confidence that we have a good understanding of the underlying physics," he added.

22.10 | 0 komentar | Read More

Supernova explosion created in lab

LONDON: Scientists have used laser beams 60,000 billion times more powerful than a laser pointer to recreate scaled supernova explosions in the laboratory to investigate one of the most energetic events in the Universe.

Supernova explosions, triggered when the fuel within a star reignites or its core collapses, launch a detonation shock wave that sweeps through a few light years of space from the exploding star in just a few hundred years.

To investigate what may cause these peculiar shapes, an international team led by Oxford University scientists has devised a method of studying supernova explosions in the laboratory instead of observing them in space.

"It may sound surprising that a table-top laboratory experiment that fits inside an average room can be used to study astrophysical objects that are light years across," said professor Gianluca Gregori of Oxford's department of Physics.

"In reality, the laws of physics are the same everywhere, and physical processes can be scaled from one to the other in the same way that waves in a bucket are comparable to waves in the ocean. So our experiments can complement observations of events such as the Cassiopeia A supernova explosion," said Gregori, who led the study.

The Cassiopeia A supernova explosion was first spotted about 300 years ago in the Cassiopeia constellation 11,000 light years away, its light has taken this long to reach us.

The optical images of the explosion show irregular 'knotty' features and associated with these are intense radio and X-ray emissions.

Whilst no one is sure what creates these phenomena one possibility is that the blast passes through a region of space that is filled with dense clumps or clouds of gas.

"Our team began by focusing three laser beams onto a carbon rod target, not much thicker than a strand of hair, in a low density gas-filled chamber," said Jena Meinecke an Oxford graduate student, who headed the experiment.

The enormous amount of heat generated more than a few million degrees celsius by the laser caused the rod to explode creating a blast that expanded out through low density gas.

In the experiments the dense gas clumps or gas clouds that surround an exploding star were simulated by introducing a plastic grid to disturb the shock front.

"The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent just like the images from Cassiopeia," said Gregori.

"We found that the magnetic field is higher with the grid than without it. Since higher magnetic fields imply a more efficient generation of radio and X-ray photons, this result confirms that the idea that supernova explosions expand into uniformly distributed interstellar material isn't always correct and it is consistent with both observations and numerical models of a shock-wave passing through a 'clumpy' medium," said Gregory.

The research was published in the journal Nature Physics.

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Getting fish drunk doubles its swim-speed

NEW YORK: A single zebrafish, exposed to alcohol, not only doubles its swim-speed among its "sober" peers, but also increases the speed of the whole group, a new study has found.

New findings by researchers at the New York University Polytechnic School of Engineering are helping to unravel the complex interplay between alcohol and social behaviour and may lead to new therapies for mitigating the negative impacts of alcohol use and abuse.

A team led by Maurizio Porfiri devised an original method that would allow for detailed tracking of a single, alcohol-exposed zebrafish amid a school of "sober" peers.

The research team posited that an individual's response to alcohol would vary based on the presence or absence of unexposed peers.

What they did not anticipate, however, was the remarkable effect the alcohol-exposed fish would have on unexposed shoalmates.

Porfiri and his colleagues designed an experimental procedure in which a single zebrafish was exposed to four concentrations of ethanol in water, ranging from zero to high.

Following exposure, the fish was released into a group of untreated zebrafish.

A custom tracking algorithm allowed the researchers to follow for the first time individual fish throughout the experiment as well as analyse group behaviour.

Previous studies show alcohol exposure affects zebrafish locomotion - at low concentrations, fish tend to swim faster, and as the dose increases, swimming typically slows. Alcohol can also negatively impact the school's cohesion.

In Porfiri's trials, the single exposed zebrafish showed changes in locomotion when observed alone consistent to those predicted by independent studies in the past.

In a group setting, however, the zebrafish behaviour was remarkably different: Fish exposed to intermediate or high alcohol concentrations nearly doubled their swimming speeds, suggesting that the presence of peers had a substantial impact on social behaviour under the influence of alcohol.

Most remarkably, the unexposed fish also modulated their behaviour and swimming speeds differentially in the presence of a shoalmate exposed to different levels of alcohol.

"These results were very surprising. It is clear that the untreated fish were matching the swimming speed of the alcohol-exposed fish, and this correlation was especially strong at an intermediate level of alcohol exposure. At very high or low levels, the influence decreases," said Porfiri.

Porfiri believes that one explanation for the high-speed swimming of the exposed individual may be hyper-reactivity to an enriched environment - ?the tank containing shoalmates.

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