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  • richardmitnick 10:29 am on March 1, 2017 Permalink | Reply
    Tags: , , , New Scientist   

    From New Scientist: “If an asteroid hit London only 3% of deaths would be from impact” 

    NewScientist

    New Scientist

    24 February 2017
    Leah Crane

    1
    Chances are it won’t land anywhere near you. Getty

    Wind kills. The most casualties from an asteroid impact won’t come from the impact itself. The wind, pressure and heat caused by the crash are far more dangerous, no matter where the asteroid hits.

    Clemens Rumpf at the University of Southampton, UK, and his colleagues have calculated the mortality risk, should an asteroid hit a residential area. They considered asteroids that burn up completely, those that hit the ground, and those that strike in water. Surprisingly, the airborne side effects were the ones that cost the most lives.

    As an asteroid hurtles towards the ground, it deposits a huge amount of energy into the atmosphere, resulting in a powerful shockwave, tornado-like winds and a plume of fire trailing behind it. When it crashes down, it forms a crater, shaking the ground around the impact and hurling debris into the air.

    If the asteroid hits water (which is twice as likely as hitting land), it would create a tsunami, with waves reaching dozens of metres high. The farther from shore the impact is, the deeper the water and the taller the waves.

    Far-reaching effect

    In the past, people have shown that tsunamis posed the greatest risks from an asteroid impact, but the events are notoriously difficult to model. Rumpf and his colleagues have worked out that the continental shelf helps protect the shore by dissipating waves both at its steep edge and over its gentle beachward slope.

    “What sets tsunamis apart is that they’re really the most far-reaching effect of all the impact effects,” says Rumpf. A pressure wave or heat plume can’t travel very far, and craters only form right at the impact site, but tsunamis can traverse hundreds of kilometres of ocean to hit coastal communities.

    A tsunami caused by the impact of a 200-metre-wide asteroid 130 kilometres off the coast of Rio de Janeiro, for example, could cause more than 50,000 deaths, with 75 per cent of those being directly caused by the tsunami and the rest due to high winds.

    But an asteroid over or in a city would kill millions. Most of those deaths would be due to wind as well, even if the asteroid did crash to the ground instead of exploding in the air.

    For an airburst, about 15 per cent of casualties would come from heat. In a direct impact, the effects of gusting wind and surging temperatures are joined by pressure waves, which can rupture internal organs.

    Only about 3 per cent of casualties would be caused by the actual impact or the earthquakes and debris that result, says the team. The group plans to discuss the results with disaster managers to come up with suggestions for preparedness.

    Very rare events

    Luckily, large asteroids don’t hit Earth often: an impact by a 200-metre asteroid is expected only once every 40,000 years. And an asteroid could fall anywhere, and most of the planet’s surface is unpopulated.

    “Chances are that an asteroid hits the water, and even if it hits land it’s much more likely that it will hit away from populated regions,” says Rumpf. “These are very rare events, but with potentially high consequences.”

    In case you are starting to worry, there are lots of projects dedicated to planetary defence against asteroids: telescopes have spotted most of the big ones, and there are several potential ways to avoid an asteroid impact if we see it coming.
    “We are in the business of detecting asteroids well in advance of an impact, so this kind of work is only really important if we totally fail to do our jobs,” says Erik Christensen, director of the Catalina Sky Survey at the University of Arizona.

    Journal reference: arXiv:1702.05798

    See the full article here .

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  • richardmitnick 7:42 am on February 23, 2017 Permalink | Reply
    Tags: Accidental find, , New Scientist, ,   

    From New Scientist: “Far-off asteroid caught cohabiting with Uranus around the sun” 

    NewScientist

    New Scientist

    16 February 2017
    Ken Croswell

    1
    Now with added Trojans. NASA/Erich Karkoschka (Univ. Arizona)

    A rare Trojan asteroid of Uranus has been found, following the same orbit as the planet. Its existence implies there could be many more of these companion asteroids, and that they are more common than we thought.

    A Trojan asteroid orbits the sun 60 degrees ahead of or behind a planet. Jupiter and Neptune have numerous Trojans, many of which have been in place for billions of years. These primordial rocks hold information about the solar system’s birth, and NASA has just announced plans to visit several of them in the 2020s and 2030s.

    But Saturn and Uranus live in a rougher neighbourhood: the giant planets on either side of them yank Trojans away through their gravitational pull. So Saturn has no known Trojan, and Uranus had only one.

    In July, though, astronomers reported a new asteroid, named 2014 YX49, that shares Uranus’s orbital period of 84 years. Now computer simulations of the solar system by brothers Carlos and Raul de la Fuente Marcos at the Complutense University of Madrid, Spain, indicate the asteroid is a Uranus Trojan. The simulations show that the asteroid has maintained its position ahead of Uranus for thousands of years.

    “It is bigger, probably twice as big as the first one,” says Carlos. The new asteroid is brighter than the first, but its exact size depends on how much light its surface reflects. If it reflects half the sunlight striking it, it’s 40 kilometres across; if it reflects 5 per cent, its diameter is 120 kilometres.

    Accidental find

    The new asteroid was found by accident, which Carlos says implies there should be more waiting to be discovered. He thinks its Trojans could number in the hundreds.

    Unlike the Trojans of Jupiter and Neptune, the simulations suggest that the two known Uranus Trojans are transient rather than permanent. Carlos suspects Uranus lacks primordial Trojans because the other giant planets kicked them away.

    The simulations indicate that the new asteroid was once a centaur, an object that skirts between the orbits of the giant planets. About 60,000 years ago, buffeted by their gravitational tugs, it was caught ahead of Uranus in its orbit around the sun and became a Trojan; it is likely to remain so for another 80,000 years, before eventually becoming a centaur again.

    Although Carlos thinks Uranus has no permanent Trojans, David Jewitt at the University of California at Los Angeles is willing to wait and see. “In the end the answer will come — as always — from observations,” he says. “People will either find permanent Uranus Trojans or not.”

    And Saturn? “The neighbourhood of Saturn is even more chaotic than that of Uranus,” Carlos says, due to Jupiter’s proximity. Still, he thinks Trojans of Saturn could exist.

    Journal references: Monthly Notices of the Royal Astronomical Society and ArXiv, arxiv.org/abs/1701.05541

    See the full article here .

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  • richardmitnick 4:13 am on December 29, 2016 Permalink | Reply
    Tags: a third of way to Earth’s core, Deepest water found 1000km down, New Scientist,   

    From Northwestern via New Scientist: “Deepest water found 1000km down, a third of way to Earth’s core” 

    Northwestern U bloc
    Northwestern University

    NewScientist

    New Scientist

    23 November 2016 [Hidden under a rock under a lake]
    Andy Coghlan

    1
    Priceless imperfection. Mederic Palot

    JULES VERNE’s idea of an ocean deep below the surface in Journey to the Centre of the Earth may not have been too far off. Earth’s mantle may contain many oceans’ worth of water – with the deepest 1000 kilometres down.

    “If it wasn’t down there, we would all be submerged,” says Steve Jacobsen at Northwestern University in Evanston, Illinois, whose team made the discovery. “This implies a bigger reservoir of water on the planet than previously thought.”

    This water is much deeper than any seen before, at a third of the way to the edge of Earth’s core. Its presence was indicated by a diamond spat out 90 million years ago by a volcano near the São Luíz river in Juina, Brazil.

    The diamond has an imperfection – a sealed-off inclusion – that contains minerals that became trapped during the diamond’s formation. When the researchers took a closer look at it with infrared microscopy, they saw unmistakable evidence of the presence of hydroxyl ions, which normally come from water. They were everywhere, says Jacobsen.

    To work out the depth the diamond formed at – and hence the origins of this water – the team again turned to the inclusion. It is made of a ferropericlase mineral, which is composed of iron and magnesium oxide, and can also absorb other metals such as chromium, aluminium and titanium at ultra-high temperatures and pressures typical of the lower mantle.

    Jacobsen found that these additional metals had separated from the ferropericlase – something that happens in the milder conditions a diamond experiences as it edges up through shallower depths. But for the metals to be present at all, the diamond must have originated in the intense conditions of the lower mantle (Lithos, doi.org/btcn). “Based on the composition of the trapped mineral, we speculate that the depth was around 1000 kilometres,” says Jacobsen.

    The clincher is that as the inclusion was trapped in the diamond the whole time, the water signature can only have come from the diamond’s place of formation in the lower mantle. “This is the deepest evidence for water recycling on the planet,” he says. “The big take-home message is that the water cycle on Earth is bigger than we ever thought, extending into the deep mantle.”

    His team has previously found evidence of massive amounts of water some 600 kilometres down, mixed in with rock.

    “Water clearly has a role in plate tectonics, and we didn’t know before how deep these effects could reach,” he says. “It has implications for the origin of water on the planet.” For example, it is possible that Earth had water from day one in the very dust and rocks that first formed it.

    But it’s still not clear exactly how water got so far down. It may have arrived in the mantle even earlier than 90 million years ago, through sedimentary oceanic crust burrowing downwards as primitive tectonic plates thrust against and past each other.

    The new study suggests cycling of subducted material, even at these depths, says Lydia Hallis at the University of Glasgow, UK. “Ultimately, this research will help us better understand the way our planet recycles itself.”

    Jacobsen thinks that this water may help explain why Earth is the only planet we know to have plate tectonics. “Water mixes with ocean crust and gets subducted at convergent plate boundaries,” he says. “Introducing water into the mantle promotes melting and weakens rock, likely helping out the motions of plates like grease.”

    The hope is that such research will yield insights into how our oceans and atmosphere formed in the first place.

    See the full article here .

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    Northwestern South Campus
    South Campus

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

    Northwestern is recognized nationally and internationally for its educational programs.

     
  • richardmitnick 1:48 pm on December 13, 2016 Permalink | Reply
    Tags: , New Scientist,   

    From New Scientist: “Quantum computers ditch all the lasers for easier engineering” 

    NewScientist

    New Scientist

    7 December 2016
    Michael Brooks

    1
    Lasers are not the only option. Richard Kail/Science Photo Library

    They will be the ultimate multitaskers – but quantum computers might take a bit of juggling to operate. Now, a team has simplified their inner workings.

    Computers that take advantage of quantum laws allowing particles to exist in multiple states at the same time promise to run millions of calculations at once. One of the candidate technologies involves ion traps, which hold and manipulate charged particles, called ions, to encode information.

    But to make a processor that works faster than a classical computer would require millions of such traps, each controlled with its own precisely aligned laser – making it extremely complicated.

    Now, Winfried Hensinger at the University of Sussex in the UK and his colleagues have replaced the millions of lasers with some static magnets and a handful of electromagnetic fields. “Our invention has led to a radical simplification of the engineering required, which means we are now able to construct a large-scale device,” he says.

    In their scheme, each ion is trapped by four permanent magnets, with a controllable voltage across the trap. The entire device is bathed in a set of tuned microwave and radio-frequency electromagnetic fields. Tweaking the voltage shifts the ions to a different position in the magnetic field, changing their state.

    Promising technology

    The researchers have already used this idea to build and operate a quantum logic gate, a building block of a processor. This particular gate involves entangling two ions – in other words, linking their quantum states such that they are fully dependent on each other. Hensinger says this is the most difficult kind of logic gate to build.

    Manas Mukherjee at the National University of Singapore is impressed with the new technology. “It’s a promising development, with good potential for scaling up,” he says.

    That’s exactly what the team is planning: they hope to have a trial device containing tens of ions ready within four years.

    The fact that the device uses current technologies such as techniques for silicon-chip manufacturing means there are no known roadblocks to scaling up to create a useful quantum computer.

    It won’t be plain sailing, though. Scaling up will mean creating magnetic fields that vary in strength over relatively short distances. This a significant engineering challenge, says Mukherjee. Then there’s the challenge of handling waste heat, which becomes more problematic as the processor gets bigger. “As with any architecture, you need low heating rates,” he says.

    Journal reference: Physical Review Letters, DOI: 10.1103/PhysRevLett.117.220501

    See the full article here .

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  • richardmitnick 11:07 am on November 25, 2016 Permalink | Reply
    Tags: , , New Scientist, ,   

    From New Scientist: “Gravity may have chased light in the early universe” 

    NewScientist

    New Scientist

    23 November 2016
    Michael Brooks

    1
    Getting up to speed. Manuela Schewe-Behnisch/EyeEm/Getty

    It’s supposed to be the most fundamental constant in physics, but the speed of light may not always have been the same. This twist on a controversial idea could overturn our standard cosmological wisdom.

    In 1998, Joao Magueijo at Imperial College London, proposed that the speed of light might vary, to solve what cosmologists call the horizon problem. This says that the universe reached a uniform temperature long before heat-carrying photons, which travel at the speed of light, had time to reach all corners of the universe.

    The standard way to explain this conundrum is an idea called inflation, which suggests that the universe went through a short period of rapid expansion early on – so the temperature evented out when the cosmos was smaller, then it suddenly grew. But we don’t know why inflation started, or stopped. So Magueijo has been looking for alternatives.

    Now, in a paper to be published 28 November in Physical Review, he and Niayesh Afshordi at the Perimeter Institute in Canada have laid out a new version of the idea – and this one is testable. They suggest that in the early universe, light and gravity propagated at different speeds.

    If photons moved faster than gravity just after the big bang, that would have let them get far enough for the universe to reach an equilibrium temperature much more quickly, the team say.

    A testable theory

    What really excites Magueijo about the idea is that it makes a specific prediction about the cosmic microwave background (CMB). This radiation, which fills the universe, was created shortly after the big bang and contains a “fossilised” imprint of the conditions of the universe.

    CMB per ESA/Planck
    CMB per ESA/Planck

    In Magueijo and Afshordi’s model, certain details about the CMB reflect the way the speed of light and the speed of gravity vary as the temperature of the universe changes. They found that there was an abrupt change at a certain point, when the ratio of the speeds of light and gravity rapidly went to infinity.

    This fixes a value called the spectral index, which describes the initial density ripples in the universe, at 0.96478 – a value that can be checked against future measurements. The latest figure, reported by the CMB-mapping Planck satellite in 2015, place the spectral index at about 0.968, which is tantalisingly close.

    ESA/Planck
    ESA/Planck

    If more data reveals a mismatch, the theory can be discarded. “That would be great – I won’t have to think about these theories again,” Magueijo says. “This whole class of theories in which the speed of light varies with respect to the speed of gravity will be ruled out.”

    But no measurement will rule out inflation entirely, because it doesn’t make specific predictions. “There is a huge space of possible inflationary theories, which makes testing the basic idea very difficult,” says Peter Coles at Cardiff University, UK. “It’s like nailing jelly to the wall.”

    That makes it all the more important to explore alternatives like varying light speeds, he adds.

    John Webb of the University of New South Wales in Sydney, Australia, has worked for many years on the idea that constants may vary, and is “very impressed” by Magueijo and Afshordi’s prediction. “A testable theory is a good theory,” he says.

    The implications could be profound. Physicists have long known there is a mismatch in the way the universe operates on its smallest scales and at its highest energies, and have sought a theory of quantum gravity to unite them. If there is a good fit between Magueijo’s theory and observations, it could bridge this gap, adding to our understanding of the universe’s first moments.

    “We have a model of the universe that embraces the idea there must be new physics at some point,” Magueijo says. “It’s complicated, obviously, but I think ultimately there will be a way of informing quantum gravity from this kind of cosmology.”

    See the full article here .

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  • richardmitnick 10:04 am on October 22, 2016 Permalink | Reply
    Tags: , , KIC 9832227, New Scientist, Red nova   

    From New Scientist: “Double star may light up the sky as rare red nova in six years” 

    NewScientist

    New Scientist

    21 October 2016
    Ken Croswell

    1
    Is another one around the corner? NASA / Hubble Heritage Team (AURA/STScI)

    A dim binary star is behaving exactly as expected if it is about to explode as a “red nova“. If that happens, in 2022 or so it could shine as brightly as the North Star.

    Dozens of ordinary novae – the temporary flare-ups of white dwarf stars stealing gas from their companion star – explode in our galaxy every year. These novae turn blue.

    In recent years, however, astronomers have discovered a rare type of nova that turns red instead. At peak brightness, many red novae rival the most luminous stars in the galaxy.

    A red nova in 2008 gave us a clue as to why these explosions happen: observations made before the blast revealed that the nova was the result of two stars orbiting each other merging into one.

    The two stars were in a so-called contact binary, orbiting so closely that they touched. If Earth circled a contact binary, our suns would look like a fiery peanut.

    Despite their exotic appearance, contact binaries are common, with nearly 40,000 known in our galaxy. Now, new observations show that one, named KIC 9832227, could be about to explode as a red nova.

    Boom star

    “My colleagues like to call it the ‘Boom Star’,” says Larry Molnar of Calvin College in Grand Rapids, Michigan.

    The binary is roughly 1700 light years from Earth, in the constellation Cygnus. The two stars whirl around each other every 11 hours.

    In 2013 and 2014, Molnar’s team discovered two things about KIC 9832227 that suggest an imminent explosion: the orbital period is decreasing, and it’s doing so at an ever-faster rate.

    This is exactly what the contact binary that sparked the 2008 red nova did. The orbital period shrank because the two stars circled each other faster as they spiralled closer together.

    Unfortunately, other effects can mimic this decrease in orbital period. For example, a third star can pull the binary toward us so that its light takes less time to reach Earth, creating the illusion that the two stars are circling each other faster. So additional observations were needed to figure out what KIC 9832227 was likely to do.

    In late 2015, astronomers in Bulgaria observed the star with a 30-centimetre telescope, and found that its period is still shrinking at an ever-faster clip. “A stellar merger is a real possibility,” says Alexander Kurtenkov of the University of Sofia.

    Molnar’s team finds this trend persisting into 2016. “At this point, I think we have a serious candidate,” he says.

    His latest observations, made with 40-centimetre telescopes in Michigan and New Mexico, put the date of the potential explosion between 2021 and 2023. But he cautions that another three years of observations are required before he can rule out alternatives. By then, if the orbital period keeps shrinking faster and faster, an impending explosion will be very likely. If it calms down, there might be a different outcome.

    KIC 9832227 is currently 12th magnitude – visible only through a telescope. But if it brightens by 10 magnitudes, as the 2008 red nova did, it will be as bright as the North Star and the brightest stars of the Big Dipper, and easily visible to the naked eye.

    See the full article here .

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  • richardmitnick 3:11 pm on October 19, 2016 Permalink | Reply
    Tags: , , EEW: Earthquake Early Warning at UC Berkeley, New Scientist, , Why San Francisco’s next quake could be much bigger than feared   

    From New Scientist: “Why San Francisco’s next quake could be much bigger than feared” 

    NewScientist

    New Scientist

    19 October 2016
    Chelsea Whyte

    1
    Geological faults lie beneath the San Francisco Bay Area. USGS/ESA

    By Chelsea Whyte

    Since reports hit last year that a potentially massive earthquake could destroy vast tracts of the west coast of the United States, my phone has rung regularly with concerned family members from the Pacific coast asking one question: how big could it possibly be?

    In the San Francisco Bay Area, new findings now show a connection between two fault lines that could result in a major earthquake clocking in at magnitude 7.4.

    At that magnitude, it would radiate five times more energy than the 1989 Loma Prieta earthquake that killed dozens, injured thousands, and cost billions of dollars in direct damage.

    .“The concerning thing with the Hayward and Rodgers Creek faults is that they’ve accumulated enough stress to be released in a major earthquake. They’re, in a sense, primed,” says Janet Watt, a geophysicist at the US Geological Survey who led the study.

    The Hayward fault’s average time between quakes is 140 years, and the last one was 148 years ago.

    “In the next 30 years, there’s a 33 per cent chance of a magnitude 6.7 or greater,” she says. These two faults combined cover 190 kilometres running parallel to their famous neighbour, the San Andreas fault, from Santa Rosa in the north down through San Pablo Bay and south right under Berkeley stadium.

    Sweeping the bay

    To map the faults, Watt and her team scanned back and forth across the bay for magnetic anomalies that crop up near fault lines. They also swept the bay with a high-frequency acoustic instrument called a chirp to image the faults’ relationship below the sea floor using radar and sonar, in a similar way to how a bat uses echolocation to “see” the shape of a cave.

    “A direct connection makes it easier for a larger earthquake to occur that ruptures both faults,” says Roland Bürgmann at the University of California, Berkeley, who studies faults in the area.

    The Hayward and Rodgers Creek faults [Science Advances] combined could produce an earthquake releasing five times more energy than the Hayward fault alone.

    “It doesn’t mean the two faults couldn’t rupture together without the connection,” says Burgmann. “And it doesn’t mean that smaller earthquakes couldn’t occur on one or the other of the two faults most of the time.”

    But it makes the scenario of the larger, linked quake more likely, he says.

    Be prepared

    Bürgmann and his colleagues have found a similar connection between the southern end of the Hayward fault and the Calaveras fault, suggesting that they ought to be treated as one continuous fault. This new work follows that fault even farther north.

    So what do I tell my mom next time she calls?

    “Most important continues to be improving preparedness at all levels,” says Bürgmann. That includes better construction, personal readiness supplies, and the implementation of earthquake early warning systems, which include sensors triggered by the first signs of a quake and send out alerts ahead of the most violent shaking.

    The state and federal governments support building such a warning system in California, an effort led by Berkeley’s Seismological Laboratory.

    See the full article here.

    QCN bloc

    Quake-Catcher Network

    IF YOU LIVE IN AN EARTHQUAKE PRONE AREA, ESPECIALLY IN CALIFORNIA, YOU CAN EASILY JOIN THE QUAKE-CATCHER NETWORK

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    BOINCLarge

    BOINC WallPaper

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

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  • richardmitnick 9:33 am on October 19, 2016 Permalink | Reply
    Tags: , , New Scientist, The Boötes void   

    From New Scientist: “Space is full of gigantic holes that are bigger than we expected” 

    NewScientist

    New Scientist

    18 October 2016
    Joshua Sokol

    1
    Very empty space. Richard Powell

    Face it, the vast darkness of space is a little eerie. It’s no wonder we usually prefer to focus on the bright spots. But it’s in the void that we might find our best explanations of the cosmos.

    In 1923, Edwin Hubble showed that the universe was far larger than expected by discovering that what we thought were swirls of gas on the edge of our own galaxy were actually galaxies in their own right: lonely “island universes” we could spot across an empty sea of black. That led to a comforting thought – we now know that even the darkest patch of sky, when seen through the telescope named after Hubble, is dotted with clumps of luminous stuff like our Milky Way.

    But there’s another view of the universe, like the horror cliché of flipping an image to its photonegative. Since 1981, when astronomers found a vacant expanse called the Boötes void, we’ve also known that the universe has holes of cold, dark, lonely nothing that are larger than anyone expected. To truly understand the universe, we may have to gaze into the abyss.

    A bubble in space

    The Boötes void, which you will assuredly not see if you look at Boötes, the “ploughman” constellation adjacent to the Big Dipper, is a rough sphere about 280 million light years in diameter.

    Galaxy-wise, it’s a ghost town. When we first saw the void, we found only one galaxy inside. Since then, we’ve detected only a few dozen more. By contrast, the Virgo Supercluster, a smaller region that includes the Milky Way, contains over 2000 galaxies.

    As residents of the Milky Way, humans are able to see one large nearby galaxy, Andromeda, with our naked eyes. The proximity of Andromeda helped Edwin Hubble look at its individual stars to unlock the true scope of the universe. If our galaxy were in the Boötes void, our nearest peers would be much farther away – perhaps allowing us to fancy ourselves at the center of the cosmos for longer.

    This is no statistical accident. At very large scales, the universe is often described as a cosmic web, with strands of invisible dark matter undergirding the universe’s luminous structure. It might be better here to think of it as cosmic foam, like soap bubbles in a bathtub. Just as it’s sudsy where bubbles intersect, galaxy clusters concentrate in walls, filaments and intersections. In between is mostly void.

    Making peace with the vacuum

    The problem was that the Boötes void was just too big. Voids grow because their dense edges have a much stronger gravitational pull than anything at their centres. But the universe wasn’t yet old enough to have inflated such a big bubble.

    For an explanation, we had to wait until the 1998 discovery of dark energy: a cosmic pressure that forces empty regions of space to expand as if someone was blowing air into each of the universe’s soap bubbles all at once.

    Many astronomers, now in a boom of cataloging and mapping voids, think these spooky regions that expose the naked fabric of the universe could point to the next big discovery.

    Soon, statistical analyses of their shapes may be able to help us measure dark energy, gravity and any mysterious new forces better than ever before. And in the process, perhaps, they will help us learn to embrace the emptiness.

    See the full article here .

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  • richardmitnick 2:34 pm on October 7, 2016 Permalink | Reply
    Tags: , First farm to grow veg in a desert using only sun and seawater, New Scientist   

    From New Scientist: “First farm to grow veg in a desert using only sun and seawater” 

    NewScientist

    New Scientist

    6 October 2016
    Alice Klein

    1
    Sundrop farm: no fossil fuels required to grow 180,000 tomato plants. Sundrop

    Sunshine and seawater. That’s all a new, futuristic-looking greenhouse needs to produce 17,000 tonnes of tomatoes per year in the South Australian desert.

    It’s the first agricultural system of its kind in the world and uses no soil, pesticides, fossil fuels or groundwater. As the demand for fresh water and energy continues to rise, this might be the face of farming in the future.

    An international team of scientists have spent the last six years fine-tuning the design – first with a pilot greenhouse built in 2010; then with a commercial-scale facility that began construction in 2014 and was officially launched today.

    How it works

    Seawater is piped 2 kilometres from the Spencer Gulf to Sundrop Farm – the 20-hectare site in the arid Port Augusta region. A solar-powered desalination plant removes the salt, creating enough fresh water to irrigate 180,000 tomato plants inside the greenhouse.

    Scorching summer temperatures and dry conditions make the region unsuitable for conventional farming, but the greenhouse is lined with seawater-soaked cardboard to keep the plants cool enough to stay healthy. In winter, solar heating keeps the greenhouse warm.

    There is no need for pesticides as seawater cleans and sterilises the air, and plants grow in coconut husks instead of soil.

    The farm’s solar power is generated by 23,000 mirrors that reflect sunlight towards a 115-metre high receiver tower. On a sunny day, up to 39 megawatts of energy can be produced – enough to power the desalination plant and supply the greenhouse’s electricity needs.

    Tomatoes produced by the greenhouse have already started being sold in Australian supermarkets.

    Future outlook

    Possible solar energy shortages in winter mean that the greenhouse still needs to be hooked up to the grid for back-up, but gradual improvements to the design will eliminate any reliance on fossil fuels, says Sundrop Farm CEO Philipp Saumweber.

    The $200 million infrastructure makes the seawater greenhouse more expensive to set up than traditional greenhouses, but the cost will pay off long-term, says Saumweber. Conventional greenhouses are more expensive to run on an annual basis because of the cost of fossil fuels, he says.

    Sundrop is now planning to launch similar sustainable greenhouses in Portugal and the US, and another in Australia. Other companies are also testing pilot seawater greenhouses in desert areas of Oman, Qatar and the United Arab Emirates.

    “These closed production systems are very clever,” says Robert Park at the University of Sydney, Australia. “I believe that systems using renewable energy sources will become better and better and increase in the future, contributing even more of some of our foods.”

    However, Paul Kristiansen at the University of New England, Australia, questions the need for energy-intensive tomato farming in a desert, when there are ideal growing conditions in other parts of Australia.

    “It’s a bit like crushing a garlic clove with a sledgehammer,” he says. “We don’t have problems growing tomatoes in Australia.”

    Nevertheless, the technology may become useful in the future if climate change causes drought in once-fertile regions, Kristiansen says. “Then it will be good to have back-up plans.”

    See the full article here .

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  • richardmitnick 9:17 am on September 29, 2016 Permalink | Reply
    Tags: , , New Scientist, , Where is the Milky Way?   

    From New Scientist: “Our home spiral arm in the Milky Way is less wimpy than thought” 

    NewScientist

    New Scientist

    28 September 2016

    It’s tricky to map an entire galaxy when you live in one of its arms. But astronomers have made the clearest map yet of the Milky Way – and it turns out that the arm that hosts our solar system is even bigger than previously thought.

    The idea that the Milky Way is a spiral was first proposed more than 150 years ago, but we only started identifying its limbs in the 1950s. Details about the galaxy’s exact structure are still hotly debated, such as the number of arms, their length and the size of the bar of hot gas and dust that stretches across its middle.

    The star-filled arms are densely packed with gas and dust, where new stars are born. That dust can obscure stars we use to measure distances, complicating the mapping process.

    .
    Two of the arms, called Perseus and Scutum-Centaurus, are larger and filled with more stars, while the Sagittarius and Outer arms have fewer stars but just as much gas. The solar system has been thought to lie in a structure called the Orion Spur, or Local Arm, which is smaller than the nearby Perseus Arm.

    1
    Artist’s conception of the Milky Way galaxy as seen from far Galactic North (in Coma Berenices) by NASA/JPL-Caltech/R. Hurt annotated with arms (colour-coded according to Milky Way article) as well as distances from the Solar System and galactic longitude with corresponding constellation.

    Just as grand

    Now, Ye Xu and colleagues from the Purple Mountain Observatory in Nanjing, China, say the Local Arm is just as grand as the others.

    Purple Mountain Observatory
    Purple Mountain Observatory in Nanjing, China

    The team used the Very Long Baseline Array in New Mexico to make extremely accurate measurements of high-mass gas clouds in the arms, and used a star-measuring trigonometry trick called parallax to measure their distances.

    NRAO VLBA
    NRAO VLBA

    “Radio telescopes can ‘see’ through the galactic plane to massive star forming regions that trace spiral structure, while optical wavelengths will be hidden by dust,” Xe says. “Achieving a highly accurate parallax is not easy.”

    The new measurements suggest the Milky Way is not a grand design spiral with well-defined arms, but a spiral with many branches and subtle spurs.

    However, Xu and colleagues say the Orion Spur is not a spur at all, but more in line with the galaxy’s other spectacular arms. The team also discovered a spur connecting the Local and Sagittarius arms.

    “This lane has received little attention in the past because it does not correspond with any of the major spiral arm features of the inner galaxy,” the authors of the study write.

    Future measurements with other radio telescopes will shed more light on the galaxy’s shape. The European Space Agency’s Gaia spacecraft is in the midst of a mission to make a three-dimensional map of our galaxy, too.

    ESA/GAIA satellite
    ESA/GAIA satellite

    More measurements of the high-mass gas regions will help astronomers determine what our galaxy looks like, from the inside out.

    Journal reference: Science Advances, DOI: 10.1126/sciadv.1600878

    See the full article here .

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