Researchers craft an LED just two atoms thick

Science - Posted On:2017-10-17 12:00:01 Source: arstechnica

Modern computers are, in many ways, limited by their energy consumption and cooling requirements. Some of that comes from the process of performing calculations. But often, the majority of energy use comes from simply getting data to the point where calculations are ready to be performed. Memory, storage, data transfer systems, and more all create power draws that, collectively, typically end up using more power than the processor itself.

Light-based communications offers the possibility of dropping power consumption while boosting the speed of connections. In most cases, designs have focused on situations where a single external laser supplies the light, which is divided and sent to the parts of the system that need it. But a new paper in Nature Nanotechnology suggests an alternate possibility: individual light sources on the chip itself. To demonstrate this possibility, the team put together an LED just two atoms thick and integrated it with a silicon chip. Better still, the same material can act as a photodetector, providing a way of building all the needed hardware using a single process.

The work relied on two different atomically thin materials. These materials consist of a planar sheet of atoms chemically linked to each other. While their study was pioneered using graphene, a sheet of carbon atoms, they developed a variety of other materials with similar structures. The materials being used here are molybdenum ditelluride (MoTe2), a semiconductor, and hexagonal boron nitride.

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Gun waiting periods prevent hundreds of homicides, according to 45-year study

Science - Posted On:2017-10-17 10:44:56 Source: arstechnica

A few days to cool off and think things through may be enough to prevent hundreds of homicides each year, according to a new study in PNAS.

A study tracking handgun laws on wait periods over a 45-year period found that a delay in obtaining a firearm after purchase reduced gun homicides by 17 percent. That breaks down to about 36 homicides per year for the average state. As of 2014, such laws in 16 states and the District of Columbia prevented about 750 gun homicides per year. If all 50 states required a wait, around 910 more lives could be spared, the authors report.

“Waiting periods would therefore reduce gun violence without imposing any restrictions on who can own a gun,” according to the authors, led by Deepak Malhotra, a negotiation and conflict-resolution expert at Harvard Business School.

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Air Force General: “We’d be dumb not to” fly on SpaceX’s reusable rockets

Science - Posted On:2017-10-17 10:44:56 Source: arstechnica

The increasingly warm relationship between the US Air Force and the rocket company SpaceX appears to be approaching full-on bromance levels. The latest words of lavish praise for SpaceX have come from Gen. John W. Raymond, commander of Air Force Space Command, which oversees launch operations for the US military and national security sectors.

In an interview with Bloomberg, Raymond said the potential savings from reusable rockets like the Falcon 9 booster now being flown and reflown by SpaceX are irresistible. “The market’s going to go that way. We’d be dumb not to,” he said. “What we have to do is make sure we do it smartly.” It would be "absolutely foolish" to not begin using them, Raymond said.

Before the military can fly its satellites and other payloads on a previously flown booster, the US military has to certify that SpaceX's "flight proven" boosters are reliable enough. That process already appears to be underway. "I don’t know how far down the road we’ve gotten, but I am completely committed to launching on a reused rocket, a previously flown rocket, and making sure that we have the processes in place to be able to make sure that we can do that safely," Raymond told Bloomberg.

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Gun waiting periods prevent hundreds of murders, according to 45-year study

Science - Posted On:2017-10-17 10:29:57 Source: arstechnica

A few days to cool off and think things through may be enough to prevent hundreds of murders each year, according to a new study in PNAS.

A study tracking handgun laws on wait periods over a 45-year period found that a delay in obtaining a firearm after purchase reduced gun homicides by 17 percent. That breaks down to about 36 murders per year for the average state. As of 2014, such laws in 16 states and the District of Columbia prevented about 750 gun homicides per year. If all 50 states required a wait, around 910 more lives could be spared, the authors report.

“Waiting periods would therefore reduce gun violence without imposing any restrictions on who can own a gun,” according to the authors, led by Deepak Malhotra, a negotiation and conflict-resolution expert at Harvard Business School.

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Google Maps Now Lets You Explore Your Local Planets and Moons

science - Posted On:2017-10-17 06:14:57 Source: slashdot

Google has added three planets and nine moons to Google Maps. "The heavenly bodies include Saturn moons Dione, Enceladus, Iapetus, Mimas, Rhea and Titan, and Jupiter moons Europa, Ganymede and Io," reports CNET. "Google also added dwarf-planets Pluto and Ceres and full-planet Venus." From the report: Once inside Google Maps for planets, you can spin the space objects around, get more information on their place names and zoom in for a closer look. The new worlds are possible thanks to imagery from NASA and the European Space Agency. NASA's dearly departed Cassini spacecraft sent back a treasure trove of views of Saturn's moons. If you have a few moments to spare, fire up a browser, go to your current location on Google Maps, enter satellite mode and hit the zoom-out button until you've left the planet and are "floating" in space. A list of available planets and moons pops up on the side and you're off on your space adventure. Read more of this story at Slashdot.

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Ophelia Became a Major Hurricane Where No Storm Had Before

science - Posted On:2017-10-16 23:44:58 Source: slashdot

An anonymous reader quotes a report from Ars Technica: The system formerly known as Hurricane Ophelia is moving into Ireland on Monday, bringing "status red" weather throughout the day to the island. The Irish National Meteorological Service, Met Eireann, has warned that, "Violent and destructive gusts of 120 to 150km/h are forecast countrywide, and in excess of these values in some very exposed and hilly areas. There is a danger to life and property." Ophelia transitioned from a hurricane to an extra-tropical system on Sunday, but that only marginally diminished its threat to Ireland and the United Kingdom on Monday, before it likely dissipates near Norway on Tuesday. The primary threat from the system was high winds, with heavy rains. Forecasters marveled at the intensification of Ophelia on Saturday, as it reached Category 3 status on the Saffir-Simpson scale and became a major hurricane. For a storm in the Atlantic basin, this is the farthest east that a major hurricane has been recorded during the satellite era of observations. Additionally, it was the farthest north, at 35.9 degrees north, that an Atlantic major hurricane has existed this late in the year since 1939. Read more of this story at Slashdot.

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Leave It To the Heat to Dull Autumn's Glory

science - Posted On:2017-10-16 14:30:00 Source: slashdot

It's autumn. Somebody tell the trees. From a report: Ordinarily, two signals alert deciduous trees that it's time to relinquish the green hues of summer in favor of autumn's yellows, oranges and reds. First, the days begin to grow shorter. Second, the temperature begins to drop. But this year, unseasonably warm weather across most of the U.S. has tricked trees into delaying the onset of fall's color extravaganza. Temperatures in the eastern half of the country have been as much as 15 degrees above normal since mid-September, and the warmth is expected to persist through the end of October. The unfortunate result for leaf peepers is a lackluster fall. Two kinds of pigments produce the season's liveliest foliage. Carotenoid, responsible for yellows and oranges, is always present in leaves but is usually masked by chlorophyll. The initial trigger for its appearance is shorter days. Anthocyanin, responsible for reds and deep purples, is different. Not all deciduous trees have this pigment, and those that do manufacture it from scratch in the fall. The primary trigger for its appearance is lower temperatures. Without that cooling cue, the colors of maple and other species that generally ignite New England with brilliant reds this time of year are likely to fizzle. Read more of this story at Slashdot.

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Astronomers Strike Gravitational Gold In Colliding Neutron Stars

science - Posted On:2017-10-16 13:00:00 Source: slashdot

For the first time, scientists have caught two neutron stars in the act of colliding, revealing that these strange smash-ups are the source of heavy elements such as gold and platinum. From a report: The discovery, announced today at a news conference and in scientific reports written by some 3,500 researchers, solves a long-standing mystery about the origin of these heavy elements -- which are found in everything from wedding rings to cellphones to nuclear weapons. It's also a dramatic demonstration of how astrophysics is being transformed by humanity's newfound ability to detect gravitational waves, ripples in the fabric of space-time that are created when massive objects spin around each other and finally collide. "It's so beautiful. It's so beautiful it makes me want to cry. It's the fulfillment of dozens, hundreds, thousands of people's efforts, but it's also the fulfillment of an idea suddenly becoming real," says Peter Saulson of Syracuse University, who has spent more than three decades working on the detection of gravitational waves. Albert Einstein predicted the existence of these ripples more than a century ago, but scientists didn't manage to detect them until 2015. Until now, they'd made only four such detections, and each time the distortions in space-time were caused by the collision of two black holes. That bizarre phenomenon, however, can't normally be seen by telescopes that look for light. Neutron stars, by contrast, spew out visible cosmic fireworks when they come together. These incredibly dense stars are as small as cities like New York and yet have more mass than our sun. Further reading: 'A New Rosetta Stone for Astronomy' (The Atlantic), and Gravitational Wave Astronomers Hit Mother Lode (Scientific American). Read more of this story at Slashdot.

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London’s sky turns red Monday, but we can’t blame pollution

Science - Posted On:2017-10-16 12:30:00 Source: arstechnica

Residents of England awoke on Monday morning to a sky that looked very much like a scene from the movie Blade Runner—red and hazy. Fortunately this isn't science fiction—or even pollution. Rather, it's a combination of the rare, powerful ex-hurricane Ophelia's winds and African dust.

The large, extra-tropical cyclone that brought high winds and damaging seas to Ireland on Monday also produced a huge swath of powerful southerly winds that brought Saharan dust from the west coast of Africa all the way north across the Atlantic and western Europe into the United Kingdom.

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How to harden a country that sits on a fault line

Science - Posted On:2017-10-16 10:44:57 Source: arstechnica

ROTORUA, New Zealand—If you head east from my parents' home in New Zealand, you'll travel through rolling hills for a while. Then, as you crest a rather unremarkable climb, an unexpectedly spectacular view opens up before you. Mokoia Island is small, bushy, and brooding, and it sits at the center of a wide blue lake in what appears to be a large valley.

But that's no valley. From the distant view of that crest, the only obvious clue lies in a large hill, grandiosely named Mount Ngongotaha, off to one side. It is not attached to the valley walls and stands alone, a land-locked cousin to Mokoia Island.

The view is from the collapsed wall of the caldera of the Rotorua volcano, part of the Okataina volcanic area. Mokoia and Ngongotaha are the remnants of eruptions that are slowly re-filling the huge volume of rock that was blasted out of Okataina in the distant past. This process is called caldera-repairing. The town of Rotorua sits right inside the caldera and is surrounded by evidence of the energy stored just beneath the surface. The town abounds with hot springs, boiling mud, and, yes, the sulfurous farts of the gods.

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Neutron stars collide, solve major astronomical mysteries

Science - Posted On:2017-10-16 10:14:56 Source: arstechnica

We've been extremely lucky. The LIGO and VIRGO detectors only operated simultaneously for a few weeks, but they were a remarkably busy few weeks. Today, those behind the joint collaboration announced that they've observed the merger of two neutron stars. And, because neutron stars don't swallow everything they encounter, the gravitational waves were accompanied by photons, including an extended afterglow. So dozens of telescopes, and many in space, had representatives involved in the announcement.

The number of major astrophysical issues cleared up by this collision is impressive. The collision was simultaneously detected with the Fermi space telescope, confirming that neutron star mergers produce a phenomenon known as a short gamma-ray burst. The gravitational waves were detected nearly simultaneously with the gamma ray burst, confirming that they move at the speed of light. And heavy elements like gold were detected in the debris, indicating that these mergers are a source of elements that would otherwise be difficult to produce in a supernova.

Finally, the gravitational waves from this event were detected over a period of roughly 100 seconds, which should allow a detailed analysis of their production.

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Ophelia became a major hurricane where no storm had before

Science - Posted On:2017-10-16 09:29:57 Source: arstechnica

The system formerly known as Hurricane Ophelia is moving into Ireland on Monday, bringing "status red" weather throughout the day to the island. The Irish National Meteorological Service, Met Éireann, has warned that, "Violent and destructive gusts of 120 to 150km/h are forecast countrywide, and in excess of these values in some very exposed and hilly areas. There is a danger to life and property."

Ophelia transitioned from a hurricane to an extra-tropical system on Sunday, but that only marginally diminished its threat to Ireland and the United Kingdom on Monday, before it likely dissipates near Norway on Tuesday. The primary threat from the system was high winds, with heavy rains.

Forecasters marveled at the intensification of Ophelia on Saturday, as it reached Category 3 status on the Saffir-Simpson scale and became a major hurricane. For a storm in the Atlantic basin, this is the farthest east that a major hurricane has been recorded during the satellite era of observations. Additionally, it was the furthest north that a major hurricane, at 35.9 degrees north, that an Atlantic major hurricane existed this late in the year since 1939.

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China's Scientists Set New International Record -- For Faked Peer Reviews

science - Posted On:2017-10-15 14:15:00 Source: slashdot

China now has more laboratory scientists than any other country in the world, reports Amy Qin in the New York Times, and spends more on research than the entire European Union. But in its rush to dominance, China has stood out in another, less boastful way. Since 2012, the country has retracted more scientific papers because of faked peer reviews than all other countries and territories put together, according to Retraction Watch, a blog that tracks and seeks to publicize retractions of research papers... In April, a scientific journal retracted 107 biology research papers, the vast majority of them written by Chinese authors, after evidence emerged that they had faked glowing reviews of their articles. Then, this summer, a Chinese gene scientist who had won celebrity status for breakthroughs once trumpeted as Nobel Prize-worthy was forced to retract his research when other scientists failed to replicate his results. At the same time, a government investigation highlighted the existence of a thriving online black market that sells everything from positive peer reviews to entire research articles... In part, these numbers may simply reflect the enormous scale of the world's most populous nation. But Chinese scientists also blame what they call the skewed incentives they say are embedded within their nation's academic system. Read more of this story at Slashdot.

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Scientists Selectively Trigger Suicide In Cancer Cells

science - Posted On:2017-10-15 12:15:00 Source: slashdot

Long-time Slashdot reader Baron_Yam quotes SciTechDaily: A team of researchers at the Albert Einstein College of Medicine reveals the first compound that directly makes cancer cells commit suicide while sparing healthy cells. The new treatment approach was directed against acute myeloid leukemia (AML) cells but may also have potential for attacking other types of cancers.... AML accounts for nearly one-third of all new leukemia cases and kills more than 10,000 Americans each year. The survival rate for patients has remained at about 30 percent for several decades, so better treatments are urgently needed. The team's computer screened a million compounds to determine the 500 most likely to bind to the "executioner protein" in cells. They then synthesized them all in their lab and evaluated their effectiveness. Read more of this story at Slashdot.

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8.5-Ton Chinese Space Station Will Crash To Earth In a Few Months

science - Posted On:2017-10-14 18:44:59 Source: slashdot

dryriver writes: China launched a space laboratory named Tiangong 1 into orbit in 2011. The space laboratory was supposed to become a symbol of China's ambitious bid to become a space superpower. After two years in space, Tiangong 1 started experiencing technical failure. Last year Chinese officials confirmed that the space laboratory had to be scrapped. The 8.5 ton heavy space laboratory has begun its descent towards Earth and is expected to crash back to Earth within the next few months. Most of the laboratory is expected to burn up in earth's atmosphere, but experts believe that pieces as heavy as 100 kilograms (220 pounds) may survive re-entry and impact earth's surface. Nobody will be able to predict with any precision where those chunks of space laboratory will land on Earth until a few hours before re-entry occurs. The chance that anyone would be harmed by Tiangong-1's debris is considered unlikely. When NASA's SkyLab fell to earth in 1979, an Australian town fined them $400 -- for littering. Read more of this story at Slashdot.

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Studying human tumors in mice may end up being misleading

Science - Posted On:2017-10-14 12:15:00 Source: arstechnica

Cancer is, unfortunately, governed by the same evolutionary rules that drive life itself. Cells in tumors are essentially competing to see which can divide the fastest. This competition drives them to pick up new mutations that can help them divide faster, survive immune attack, resist drugs, and expand to new areas of the body.

We can tell this by looking at the genetic changes that occur as tumors progress. Over time, we can trace the appearance of new mutations that confer abilities that are, from cancer's perspective, useful for tumor cells.

Now, a new study suggests that an unfortunate side effect of these evolutionary changes is that human tumors are really difficult to study. Whether the tumor cells are put in a culture dish or grown in mice, they evolve changes that help them grow in this new environment. And some of these changes influence how the tumor cells respond to drugs.

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Magic Mushrooms 'Reboot' Brain In Depressed People, Study Suggests

science - Posted On:2017-10-13 23:44:59 Source: slashdot

An anonymous reader quotes a report from The Guardian: Magic mushrooms may effectively "reset" the activity of key brain circuits known to play a role in depression, the latest study to highlight the therapeutic benefits of psychedelics suggests. Psychedelics have shown promising results in the treatment of depression and addictions in a number of clinical trials over the last decade. Imperial College London researchers used psilocybin -- the psychoactive compound that occurs naturally in magic mushrooms -- to treat a small number of patients with depression, monitoring their brain function, before and after. Images of patients' brains revealed changes in brain activity that were associated with marked and lasting reductions in depressive symptoms and participants in the trial reported benefits lasting up to five weeks after treatment. Dr Robin Carhart-Harris, head of psychedelic research at Imperial, who led the study, said: "We have shown for the first time clear changes in brain activity in depressed people treated with psilocybin after failing to respond to conventional treatments. Several of our patients described feeling 'reset' after the treatment and often used computer analogies. For example, one said he felt like his brain had been 'defragged' like a computer hard drive, and another said he felt 'rebooted.' Psilocybin may be giving these individuals the temporary 'kick start' they need to break out of their depressive states and these imaging results do tentatively support a 'reset' analogy. Similar brain effects to these have been seen with electroconvulsive therapy." The study has been published in Scientific Reports. Read more of this story at Slashdot.

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Media coverage of climate negotiations greeted with indifference

Science - Posted On:2017-10-13 15:15:00 Source: arstechnica

As the withdrawal of the US from the Paris Agreement demonstrates, the agreement is not a binding contract requiring countries to act on climate change. In fact, given the fact that the emissions pledges in the agreement were voluntary, political and civic engagement will play an important role in ensuring that governments keep to their pledges.

So, did the widespread media coverage of COP21 negotiations in Paris make any headway towards achieving this kind of civic engagement with climate policy? According to a paper in this week's Nature Climate Change, it seems as though coverage may have done the opposite. People's understanding of the issues at stake improved slightly over the course of the conference, but not much changed in their sense of personal or national responsibility. If anything, the authors write, “this global media event had a modest appeasing rather than mobilizing effect.”

A team of economists, psychologists and media researchers in Germany used the opportunity of COP21 to study how a media event of this kind might shape individual thinking about an important political issue like climate change. Michael Brüggemann and his colleagues conducted a three-part survey, asking the same group of people in Germany a series of questions about climate change before, during, and after COP21.

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Pumping liquid metal at 1,400°C opens the door for better solar thermal systems

Science - Posted On:2017-10-13 12:45:00 Source: arstechnica

Researchers from the Georgia Institute of Technology, Stanford, and Purdue University have built a ceramic mechanical pump that can move liquid metal as hot as 1,673K (that is, about 1,400 degrees Celsius). Usually, the temperature of liquid metals that you can pump tends to cap out at 1,300K (1,027 degrees Celsius) because there are few pump-building materials that will stay solid and chemically stable beyond that. Those materials that exist tend to crack or break quickly under the stress of such heat.

But this new pump, made of carefully engineered ceramic, could be good news for concentrated solar power, as well as accompanying thermal energy storage.

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The E in E. coli now stands for electronics

Science - Posted On:2017-10-13 07:44:57 Source: arstechnica

Synthetic biology—our attempt to engineer living organisms—has put a lot of effort into making genetic circuitry mimic what we do in silicon. Logical gates, amplifiers, and more have all been implemented using DNA and proteins. While these feats of genetic engineering have been impressive, how we'd put these genetic circuits to use hasn't always been clear. It's easy to imagine a logical gate in a bacteria would be useful for various biotechnology applications, but there haven't been many opportunities when someone put one to use.

An exception to this was reported in this week's edition of Nature Biotechnology. A team at Duke University has engineered a bacterial population that uses engineered genetic circuitry to express a protein only in specific locations. The researchers then printed these bacteria onto a surface and processed them to coat the protein in gold. The result is a tiny gold dome that makes a great pressure sensor.

The circuit itself is interesting in its own right. One part of it is pretty simple: a gene encodes a protein that feeds back to the gene itself, making sure it's active. Thus, once this gene becomes activated, it stays activated unless something else happens.

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