Recent Updates Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 3:30 pm on September 17, 2019 Permalink | Reply
    Tags: "LS2 Report: CMS set to glitter with installation of new GEMs", , , GEMs-Gas Electron Multipliers, , , ,   

    From CERN CMS: “LS2 Report: CMS set to glitter with installation of new GEMs” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN CMS

    17 September, 2019
    Achintya Rao

    1
    The GEMs being installed in CMS (Image: Maximilien Brice/CERN)

    Muons – heavy, weakly interacting particles – zip past the inner layers of the Compact Muon Solenoid (CMS), after being produced in collisions by the Large Hadron Collider (LHC). They are observed using special detectors placed on the periphery of the cylindrical device, where they are the particles most likely to register a signal. Although CMS, as the name suggests, was designed with the ability to observe with high precision nearly every muon produced within it, it will become more challenging to do so in a few years’ time. The High-Luminosity LHC (HL-LHC) will begin operations in 2026, providing on average over five times more simultaneous proton–proton collisions than before. Various components of CMS, including the muon system, are being upgraded during the ongoing second long shutdown (LS2) of CERN’s accelerator complex, in order to cope with the HL-LHC’s higher data rates.

    Muon detectors contain different mixtures of gases that get ionised when high-energy muons fly through them, providing information about where the muon was at a given instant. The CMS muon system has so far used three different types of detectors: Drift Tubes (DT), Cathode Strip Chambers (CSC) and Resistive Plate Chambers (RPC). Around a decade ago, at about the time that CMS began collecting LHC collision data, it was decided to build a completely new type of detector called Gas Electron Multipliers, or GEM, to improve the muon-detection abilities of CMS in the HL-LHC era. After extensive R&D, the first GEMs were assembled and tested at CERN’s Prévessin site in a dedicated fabrication facility. In July, two of 72 so-called “superchambers” of GEMs were transported carefully to Point 5 and installed within CMS. Each superchamber had a bottle of gas strapped on top of it on the trolley so the detector could keep “breathing” the inert air. The remaining 70 superchambers will be installed later in LS2.

    “The GEMs are new technology for CMS and Run 3 of the LHC will give us the opportunity to evaluate their performance,” says Archana Sharma, who has led the CMS-GEM team since 2009. “Of course,” she continues, “it’s not only there to be tested. The first GEMs will work with the existing CSCs to provide valuable triggering information to select the most interesting collision events.” Two more GEM stations with 288 and 216 modules respectively will be definitively installed in the coming years, in time for the HL-LHC.

    The muon-system team have been busy upgrading the electronics of the 180 CSCs located closest to the beam line to prepare for the HL-LHC. “We have already removed, refurbished and reinstalled 54 CSCs this year,” notes Anna Colaleo, CMS muon-system manager. “Work on replacing the electronics for another batch of CSCs is in progress and we plan on completing this endeavour by the summer of 2020.”


    A timelapse showing the extraction of CSCs from the CMS endcap and their transport to the refurbishment area on the surface (Video: CMS/CERN)

    CMS is also performing critical maintenance on the rest of the muon detectors during LS2. As expected, over the course of several years of operation, some components of these detectors have deteriorated slightly. The RPCs have been made more airtight to reduce gas leaks, while both DTs and RPCs have had some broken components replaced. In addition, neutron shielding is being added to the top of the DTs located in the central barrel to protect CMS from the neutron background caused by the particle beam interacting with the beam pipe.

    With nearly a year and a half of LS2 left, the CMS experiment site at LHC Point 5 continues to be a hub of activity as the collaboration prepares for the LHC’s Run 3 and beyond.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    CMS
    CERN CMS New

     
  • richardmitnick 1:00 pm on September 17, 2019 Permalink | Reply
    Tags: , , , , , Homestake Mining Company, James Whitlock and Carson Sharp, , , Ray Davis and the Solar Neutrino Experiment, RBCs-Rotating Biological Contactors, , Terry Mudder, The bacterium "pseudomonas paucimobilis mudlock", WWTP- $10 million Wastewater Treatment Plant   

    From Sanford Underground Research Facility: “The extremophiles that saved the waterways” 

    SURF logo
    Sanford Underground levels

    From Sanford Underground Research Facility


    Homestake Mining Company

    September 16, 2019
    Erin Broberg

    1
    James Whitlock, chemist for Homestake Mining Company in the 1970s and 80s, at his home in Spearfish, SD in 2019. Photo by Erin Broberg

    In the 1970s, while Ray Davis was underground taking data with the Solar Neutrino Experiment, another chemist was at work on the surface of Homestake Mining Company (Homestake).

    2
    The idea of housing physics research at Sanford Lab came long before its official conversion to a research facility. The first physics experiment came to Homestake Mine in the mid-1960s when Dr. Ray Davis, a chemist from Brookhaven National Lab, began building his solar neutrino experiment on the 4850 Level. Despite nearly three decades of counting neutrinos, Davis consistently found only one-third of the number predicted. This became known as the solar neutrino problem. Eventually the problem was solved through new understandings in neutrino physics. By the time Ray Davis received the Nobel Prize in Physics in 2002, the deep caverns of the mine were coveted for continued particle physics research.

    While Davis puzzled over the solar neutrino problem, chemist James Whitlock was working to clean up the waterways of the Black Hills. Although the transition of the facility to a full-fledged science laboratory was decades away, both researchers were forerunners in the fields of physics and biology, respectively, that would be studied there.

    An industrial waste crisis

    The Black Hills today are traced by clear-flowing creeks, dotted with lakes and awash with aquatic life. Just 50 years ago, however, the view from banks in the Black Hills was quite different.

    Then, America was facing an industrial waste crisis. Industries, including mining, manufacturing and even agriculture, were leaking waste into waterways, contaminating the nation’s underground water sources.

    In response, the Environmental Protection Agency was created in 1970, followed by the Clean Water Act in 1972, which introduced regulations that stymied the discharge of pollutants into the nation’s surface waters, including lakes, rivers, streams, wetlands and coastal areas. Industries were facing new regulations and desperately searching for ways to clean their waste and remain in operation.

    Many areas in Black Hills bore the mark of this environmental crisis. “I remember Whitewood Creek growing up, but I would’ve never called it a creek then,” said Whitlock, who grew up just 20 miles away in Spearfish.

    That’s because, for most of the 20th century, Whitewood Creek flowed through the South Dakota towns of Lead and Deadwood, clogged with tailings and laced with toxic chemicals. The creek was grey, thick as sludge and known locally as “Cyanide Creek.”

    Mining companies had long used cyanide to extract gold ore from crushed rock, releasing the tailings and chemicals into waterways. Whitewood Creek had become more than a local eyesore; full of pollutants, its path wound from the Northern Hills, pouring into the Cheyenne River, then the Missouri River and eventually the Mississippi River.

    By the time Whitlock began working as a biochemist at Homestake, the mine was searching for a way to reverse industrial impacts to the area. In 1977, Homestake completed a tailings dam in Grizzly Gulch where heavy tailings could settle out of the water instead of clogging the creek. This, however, was mostly a superficial solution.

    “The problem was, all of the cyanide and toxic metals were still flowing down the stream,” said Whitlock. “It looked cleaner, but from a toxicity standpoint, it wasn’t. There wasn’t any life.”

    Homestake turned to its team of chemists, which included Whitlock; Carson Sharp, chief chemist; and Terry Mudder, environmental engineer.

    “We tried chemical processes first,” said Whitlock. “But even if we were able to get rid of the cyanide with chemicals, the process itself created a leftover chemical soup that nothing could live in.”

    A living, breathing solution

    After a bleak meeting between Homestake officials and EPA lawyers, Whitlock sighed and turned to the EPA representative who sat next to him. “It’s too bad we never had time to try a biological option,” he said. The representative paused, yet said nothing. When the meeting reconvened, it was announced that Homestake had six months to find a biological option that would allow Homestake to continue operating.

    “I honestly don’t think anyone thought a biological solution would work,” said Whitlock. “I think both sides were buying time. It was a bit of a fluke, really.”

    Still, the team went to work, determined to use the allotted time to explore biological solutions.

    “When I was in graduate school, we didn’t have amino acid and DNA analyzers. One of the tests for identifying bacteria was that certain types could tolerate cyanide and some couldn’t,” said Whitlock. “I thought, well, if they can tolerate it, they have to have a mechanism that allows that.”

    The group discovered Whitewood Creek wasn’t completely lifeless. Certain extreme lifeforms were not only surviving in spite of the cyanide-laden water but had adapted to survive because of it. These extremophiles were using cyanide as an energy source.

    By slowly introducing these bacteria to higher concentrations of cyanide, the team developed a strain that could breakdown Homestake’s cyanide waste. The bacterium was dubbed “pseudomonas paucimobilis mudlock,” taking its last name from the scientists who developed it, Mudder and Whitlock.

    Although multiple tests proved that the cyanide was removed, the next challenge was convincing others that the novel process of using living organisms to treat a poisonous chemical problem was legitimate—and worth the construction of a multimillion-dollar wastewater treatment plant.

    Biological treatment was a novel idea at the time, especially to those outside the scientific community. Many officials within the EPA, and Homestake itself, were skeptical of this untried process. The team built a bioassay tank and filled it with biologically treated wastewater, then stocked it with trout, giving the skeptics visible proof of the microscopic change.

    “We showed that not only did the trout survive, but actually, with the warm water, their growth rate was a lot faster and they were actually healthier,” said Whitlock.

    Whitlock helped design the $10 million Wastewater Treatment Plant (WWTP) and the patented technology that would set nationwide trends, making Homestake an industry leader in wastewater treatment processes.

    3
    Present-day Waste Water Treatment Plant at Sanford Underground Research Facility. Photo by Matthew Kapust

    “In 1983, we got it in full-scale operation,” said Whitlock. “Within half a year, we did bioassessments on the stream—we started seeing organisms, fish coming upstream, and, within the first year or two, they caught a state record trout.”

    In 1985, the same Time Magazine article that decried the water crisis in America, ended with a segment entitled “Turning to New Technologies” that showcased Homestake’s patented design for wastewater treatment.

    How it works

    The defining feature of the WWTP were dozens of Rotating Biological Contactors, or RBCs, that housed millions of thriving bacteria.

    4
    Present-day Waste Water Treatment Plant at Sanford Underground Research Facility. Photo by Matthew Kapust

    Once it was pumped from the underground or received from the cyanide breakdown process, the water flowed through the slowly rotating RBCs. The slow rotation of the cylinders allowed the bacteria to alternate between contact with the water below and much-needed oxygen above.

    The first set of RBCs housed bacteria that broke down cyanide. “Cyanide is carbon and nitrogen, with a little triple bond between them. The bacteria didn’t actually eat the carbon or nitrogen. Instead, they are cutting that bond; that’s where they get their energy,” explained Whitlock.

    When the bond broke, carbon became CO2 and the nitrogen became ammonia, a toxic byproduct. The second set of RBCs housed bacteria that broke ammonia into nitrates, then further into nitrites, that could be discharged safely into the creek. The bacteria also absorbed suspended metals, including iron, silver, copper, lead and mercury.

    “The beautiful thing about using bacteria,” Whitlock noted, “is that you don’t have to pay them. They do the work for food, and the food is the waste you’re trying to get rid of anyway.”

    Over time, the bacteria even adapted to fluctuations in the wastewater, something that a chemical plant would be unable to cope with.

    “There were a thousand different types of bacteria in there, everything that comes out of the mine or the tailings impoundment,” said Whitlock. “If you only had a single chemical to break down cyanide, you’d be dead in the water from a single spill. But living organisms can adapt. We got so we hardly ever saw an upset.”

    Impacting future operations

    The WWTP continued to operate until 2002, when the declining cost of gold forced Homestake to close. Whitlock worked with Homestake for 13 years before leaving to become a consultant for similar industries trying to reduce waste. He married Carson Sharp in 1986. They traveled to Russia, Africa, Canada, Mexico and South America as waste treatment consultants before eventually returning to Spearfish.

    5
    The effluent of Sanford Underground Research Facility’s Waste Water Treatment Plant, originally designed by Homestake Mining Company, meets Gold Run Creek, which flows into Whitewood Creek. Photo by Matthew Kapust.

    When the facility reopened in 2007 and began to transition into a science facility, Whitlock worked for Sanford Underground Research Facility (Sanford Lab) for seven years to help rehabilitate the WWTP. Because no gold is being processed, the treatment plant uses fewer RBCs, treating only suspended metals and trace amounts of ammonia in water pumped from the underground workings. Using the technologies perfected by Homestake, the plant is still a leader in environmental responsibility, continuing to monitor the health of nearby creeks, counting fish and macro invertebrate populations.

    Epilogue

    Today, the field that was marked by skepticism is now a leader in industry. Biologists from around the world still come to the facility to study fascinating organisms, however, they focus on those that thrive underground. They gather samples from a number of levels and areas with different temperatures, chemical properties and geologic mineralogies.

    In Sanford Lab’s unique ecosystems, researchers have discovered extremophiles that have evolved to survive by consuming methane. Other microbes generate their own electricity with bioelectrochemical systems. Still others are being studied to understand how life could survive on other planets with similar stressors, like extreme heat, temperature, pressure, radiation and lack of sunlight.

    Researchers hope that these life forms, like the bacteria discovered in the 1970s, will lead to industry and medical advances, as well as environmental restoration.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.

    LBNL LZ project at SURF, Lead, SD, USA, will replace LUX at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    The recently assembled LUX-ZEPLIN xenon detector in the Surface Assembly Lab cleanroom at SURF

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    FNAL LBNE/DUNE from FNAL to SURF, Lead, South Dakota, USA


    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 9:24 am on September 17, 2019 Permalink | Reply
    Tags: , , , , , , , Ringing black holes,   

    From Science News: “Gravitational waves from a ringing black hole support the no-hair theorem” 

    From Science News

    September 16, 2019
    Emily Conover

    General relativity suggests the spacetime oddities can be fully described by their mass and spin.

    1

    After two black holes collide and meld into one, the new black hole “rings” (illustrated), emitting gravitational waves before settling down into a quiet state. M. Isi/MIT, NASA

    For black holes, it’s tough to stand out from the crowd: Donning a mohawk is a no-no.

    Ripples in spacetime produced as two black holes merged into one suggest that the behemoths have no “hair,” scientists report in the Sept. 13 Physical Review Letters. That’s another way of saying that, as predicted by Einstein’s general theory of relativity, black holes have no distinguishing characteristics aside from mass and the rate at which they spin (SN: 9/24/10).

    “Black holes are very simple objects, in some sense,” says physicist Maximiliano Isi of MIT.

    Detected by the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, in 2015, the spacetime ripples resulted from a fateful encounter between two black holes, which spiraled around each other before crashing together to form one big black hole (SN: 2/11/16).

    MIT /Caltech Advanced aLigo

    In the aftermath of that coalescence, the newly formed big black hole went through a period of “ringdown.” It oscillated over several milliseconds as it emitted gravitational waves, similar to the way a struck bell vibrates and makes sound waves before eventually quieting down.

    Reverberating black holes emit gravitational waves not at a single frequency, but with additional, short-lived frequencies known as overtones — much like a bell rings with multiple tones in addition to its main pitch.

    Measuring the ringing black hole’s main frequency as well as one overtone allowed the researchers to compare those waves with the prediction for a hairless black hole. The results agreed within 20 percent.

    That result still leaves some wiggle room for the no-hair theorem to be proved wrong. But, “It’s a clear demonstration that the method works,” says physicist Leo Stein of the University of Mississippi in Oxford, who was not involved with the research. “And hopefully the precision will increase as LIGO improves.”

    The researchers also calculated the mass and spin of the black hole, using only waves from the ringdown period. The figures agreed with the values estimated from the entire event — including the spiraling and merging of the original two black holes — and so reinforced the idea that the resulting black hole’s behavior was determined entirely by its mass and spin.

    But just as a mostly bald man may sport a few strands, black holes could reveal some hair on closer inspection. If they do, that might lead to a solution to the information paradox, a puzzle about what happens to information that falls into a black hole (SN: 5/16/14). For example, in a 2016 attempt to resolve the paradox, physicist Stephen Hawking and colleagues suggested that black holes might have “soft hair” (SN: 4/3/18).

    “It could still be that these objects have more mysteries to them that will only be revealed by future, more sensitive measurements,” Isi says.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 8:45 am on September 17, 2019 Permalink | Reply
    Tags: "Explainer: what happens when magnetic north and true north align?", Agonic lines, Angle of declination, Geographic north, ,   

    From CSIROscope: “Explainer: what happens when magnetic north and true north align?” 

    CSIRO bloc

    From CSIROscope

    17 September 2019
    Paul Wilkes

    1
    Very rarely, depending on where you are in the world, your compass can actually point to true north. Image: Shutterstock

    At some point in recent weeks, a once-in-a-lifetime event happened for people at Greenwich in the United Kingdom.

    Magnetic compasses at the historic London area, known as the home of the Prime Meridian, were said to have pointed directly at the north geographic pole for the first time in 360 years.

    This means that, for someone at Greenwich, magnetic north (the direction in which a compass needle points) would have been in exact alignment with geographic north.

    Geographic north (also called “true north”) is the direction towards the fixed point we call the North Pole.

    Magnetic north is the direction towards the north magnetic pole, which is a wandering point where the Earth’s magnetic field goes vertically down into the planet.

    The north magnetic pole is currently about 400km south of the north geographic pole, but can move to about 1,000km away.

    2
    The lines of the Earth’s magnetic field come vertically out of the Earth at the south magnetic pole and go vertically down into the Earth at the north magnetic pole. Image: Nasky/Shutterstock

    How do the norths align?

    Magnetic north and geographic north align when the so-called “angle of declination”, the difference between the two norths at a particular location, is 0°.

    Declination is the angle in the horizontal plane between magnetic north and geographic north. It changes with time and geographic location.

    On a map of the Earth, lines along which there is zero declination are called agonic lines. Agonic lines follow variable paths depending on time variation in the Earth’s magnetic field.

    3
    The declination angle varies between -90° and +90°.

    Currently, zero declination is occurring in some parts of Western Australia, and will likely move westward in coming years.

    That said, it’s hard to predict exactly when an area will have zero declination. This is because the rate of change is slow and current models of the Earth’s magnetic field only cover a few years, and are updated at roughly five-year intervals.

    At some locations, alignment between magnetic north and geographic north is very unlikely at any time, based on predictions.

    4
    Locations on this 2019 map with a green contour line have zero declination. Lines along which declination is zero are called agonic lines.

    The ever-changing magnetic poles

    Most compasses point towards Earth’s north magnetic pole, which is usually in a different place to the north geographic pole. The location of the magnetic poles is constantly changing.

    Earth’s magnetic poles exist because of its magnetic field, which is produced by electric currents in the liquid part of its core. This magnetic field is defined by intensity and two angles, inclination and declination.

    The relationship between geographic location and declination is something people using magnetic compasses have to consider. Declination is the reason a compass reading for north in one location is different to a reading for north in another, especially if there is considerable distance between both locations.

    Bush walkers have to be mindful of declination. In Perth, declination is currently close to 0° but in eastern Australia it can be up to 12°. This difference can be significant. If a bush walker following a magnetic compass disregards the local value of declination, they may walk in the wrong direction.

    The polarity of Earth’s magnetic poles has also changed over time and has undergone pole reversals. This was significant as we learnt more about plate tectonics in the 1960s, because it linked the idea of seafloor spreading from mid-ocean ridges to magnetic pole reversals.

    Geographic north

    Geographic north, perhaps the more straightforward of the two, is the direction that points straight at the North Pole from any location on Earth.

    When flying an aircraft from A to B, we use directions based on geographic north. This is because we have accurate geographic locations for places and need to follow precise routes between them, usually trying to minimise fuel use by taking the shortest route. All GPS navigation uses geographic location.

    Geographic coordinates, latitude and longitude, are defined relative to Earth’s spheroidal shape. The geographic poles are at latitudes of 90°N (North Pole) and 90°S (South Pole), whereas the Equator is at 0°.

    An alignment at Greenwich

    For hundreds of years, declination at Greenwich was negative, meaning compass needles were pointing west of true north.

    At the time of writing this article I used an online calculator to discover that, at the Greenwich Observatory, the Earth’s magnetic field currently has a declination just above zero, about +0.011°.

    The average rate of change in the area is about 0.19° per year, which at Greenwich’s latitude represents about 20km per year. This means next year, locations about 20km west of Greenwich will have zero declination.

    It’s impossible to say how long compasses at Greenwich will now point east of true north.

    Regardless, an alignment after 360 years at the home of the Prime Meridian is undoubtedly a once-in-a-lifetime occurrence.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    So what can we expect these new radio projects to discover? We have no idea, but history tells us that they are almost certain to deliver some major surprises.

    Making these new discoveries may not be so simple. Gone are the days when astronomers could just notice something odd as they browse their tables and graphs.

    Nowadays, astronomers are more likely to be distilling their answers from carefully-posed queries to databases containing petabytes of data. Human brains are just not up to the job of making unexpected discoveries in these circumstances, and instead we will need to develop “learning machines” to help us discover the unexpected.

    With the right tools and careful insight, who knows what we might find.

    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 8:16 am on September 17, 2019 Permalink | Reply
    Tags: , , , , Professor Martina Stenzel, ,   

    From University of New South Wales: Women in STEM-“UNSW scientist first woman honoured with top chemistry prize” Professor Martina Stenzel 

    U NSW bloc

    From University of New South Wales

    17 Sep 2019
    Lucy Carroll

    Professor Martina Stenzel is the first woman in almost 90 years to be awarded the Royal Society of NSW’s Liversidge Medal.

    1

    One of the world’s leading experts in polymer chemistry, UNSW Sydney Scientia Professor Martina Stenzel, is the first woman to receive the Royal Society of NSW’s Liversidge Medal.

    The top science prize, which has been running since 1931, recognises Australian scientists who have made an outstanding contribution to chemistry research.

    Professor Stenzel, from UNSW Science’s School of Chemistry, is widely regarded as a global pioneer in the application of novel polymer architectures. By developing chemical techniques for new polymer architectures, Professor Stenzel is creating ‘smart’ nanoparticles for drug delivery that are revolutionising the way disease is targeted and treated.

    Her work focuses on the fundamental processes that underpin nanoparticle design to make them suitable for the delivery of proteins, DNA or metal-based drugs to treat cancer – specifically ovarian and pancreatic cancer.

    “The Liversidge Medal is such an established prize and it is truly wonderful to be recognised by this enduring and respected scientific academy,” Professor Stenzel said. “I hope it will encourage more women to enter the fields of chemistry and physics, two natural sciences where female scientists have traditionally been very few and far between.”

    As Co-Director at UNSW’s Centre for Advanced Macromolecular Design, Professor Stenzel leads a team of 20 researchers working to combine synthetic polymers with nature’s building blocks such as carbohydrates, peptides and proteins. The team of researches work at the intersection of polymer science, nanoparticle design and medicine.

    The creation and adaptation of nanoparticles for various biomedical applications is the focus of Professor Stenzel’s current research. By designing nanoparticles of different shapes, sizes and surface functionalities the nanoparticles can then be “loaded” with various drugs, mimicking a water-filled sponge.

    “The beautiful thing about nanoparticles is that they can be modified in endless ways,” Professor Stenzel said. “We are trying to better understand the physical properties of these drug-loaded nanoparticles as it is directly linked to the biological activity. The aim is to create nanoparticles with the right properties that can invade cancer cells but not attack healthy cells.

    “It is incredibly exciting to be able to work more closely with medical researchers, including the ovarian cancer researcher UNSW’s Associate Professor Caroline Ford and pancreatic researchers Associate Professor Joshua McCarroll and Associate Professor Phoebe Phillips to test the ability of patented protein-based nanoparticles to help treat some of the most challenging cancers.”

    Professor Stenzel said that while nanoparticles were most commonly used in cancer treatment, they could potentially be so used for treatment of many other diseases, including Parkinson’s disease, Alzheimer’s, diabetes and infectious diseases.

    Professor Stenzel is a recipient of the LeFevre Medal from the Australian Academy of Science, the H.G. Smith Medal of the Royal Australian Chemical Institute RACI and in 2018 was elected to the Australian Academy of Science.

    The Liversidge Lecture, awarded every two years, is given on the recommendation of the Royal Australian Chemical Institute (RACI). UNSW Scientia Professor Justin Gooding was the last recipient of the award in 2016.

    Professor Stenzel will give the Liversidge Lecture in February 2020. The lectures are published in the Journal and Proceedings of the Society.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U NSW Campus

    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
  • richardmitnick 7:58 am on September 17, 2019 Permalink | Reply
    Tags: "Using a data cube to assess changes in the Earth system", , , , Earth System Data Lab,   

    From European Space Agency: “Using a data cube to assess changes in the Earth system” 

    ESA Space For Europe Banner

    From European Space Agency

    16 September 2019

    1
    Changing Arctic productivity
    Derived from FLUXCOM land–atmosphere energy fluxes, hosted on the Earth System Data Lab
    In parts of the Arctic tundra, temperatures are increasing rapidly as a result of climate change. This has resulted in complex changes in plant communities, with satellite data showing that some parts of the Arctic are ‘greening’ whilst other areas are said to be ‘browning’. Using the Earth System Data Lab, scientists are looking at components such as rock or soil types to understand changes in plant productivity in the Arctic, beyond just temperature. The image shows changes in mean maximum gross primary productivity across five years between 2001–2005 and 2011–2015 at high latitudes (>60°N). Notable changes in gross primary productivity are evident including large increases in northern Canada, and decreases in parts of Alaska and Siberia, highlighting the heterogeneous pattern of productivity change over time.

    Researchers all over the world have a wealth of satellite data at their fingertips to understand global change, but turning a multitude of different data into actual information can pose a challenge. Using examples of Arctic greening and drought, scientists at ESA’s ɸ-week showed how the Earth System Data Lab is making this task much easier.

    ESA’s Earth System Data Lab is a new virtual lab to access a wide array of Earth observations across space, time and variables. It consists of two elements: the data cube and an interface to execute different analyses on the data cube.

    Last year, ESA put out a call – an Early Adopters Call – for young researchers to explore information from data streams produced by several international scientific teams to help shape the future of the Earth System Data Lab.

    Some of these young researchers using the Earth System Data Lab were at ESA’s ɸ-week presenting their findings on, for example, Arctic greening and drought.

    In parts of the Arctic tundra, temperatures are increasing rapidly as a result of climate change. This has resulted in complex changes in plant communities, with satellite data showing that some parts of the Arctic are ‘greening’ whilst other areas are said to be ‘browning’. Understanding changes at high latitudes is crucial as they could be used to predict changes in other places that haven’t yet warmed as much.

    Oliver Baines, from the University of Nottingham in the UK, said, “The work I presented examines whether the inclusion of geodiversity components, such as rock or soil types, can improve our understanding of changes in plant productivity in the Arctic, beyond considering just temperature.

    “Using the Earth System Data Lab, we have been able to examine these relationships to identify the role of abiotic nature at a much larger scale than before.”

    By providing a set of pre-processed datasets all in one place, the virtual lab has made it easier to access, manipulate and analyse different variables including climate, gross primary productivity related to photosynthesis, aerosols and sea-surface temperatures.

    Mr Baines continues, “The hope is that by including a wider variety of abiotic nature, our understanding of changes in the Arctic can be improved and, subsequently, that any future predictions of Arctic environmental change can be refined.”

    The data cube can reveal where big anomalies occur. In the light of the last two summers when Europe was hit by unprecedented heatwaves, and this year’s devastating fires in the Amazon, the relevance of the work being carried out through the virtual lab becomes clear.

    Miguel Mahecha, from the Max Planck Institute for Biogeochemistry in Germany, said, “Only if we succeed in putting these impacts into a global perspective, will we be able to objectively judge their impacts. And, even more importantly, understand and anticipate their impacts under future climate conditions.”

    However, while the question of weather extremes is an issue, long-term change and climate change are a global concern.

    “Large parts of South America, for example, have become less productive and drier over the past decade. But there is a need to understand if this is a real change or just decadal variability. And, the Earth System Data Lab is helping us with this research,” continued Mr Mahecha.

    Another Early Adopter, Karina Winkler from the Karlsruhe Institute of Technology, Germany, is working on using reconstructed land-use data and multiple satellite-derived variables from the Earth System Data Lab. The objective of the project is to model biomass distribution by using deep learning – which shows the potential of reconstructing changes of above-ground biomass over time and at a global scale.

    ESA’s ɸ-week gave researchers the unique opportunity to share and discuss their research and reflect on the value of this new data cube they have to hand.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

     
  • richardmitnick 7:21 am on September 17, 2019 Permalink | Reply
    Tags: "New NASA Mission To Investigate Europa For Signs Of Life", , , , , , NASA’s Clipper mission   

    From Ethan Siegel: “New NASA Mission To Investigate Europa For Signs Of Life” 

    From Ethan Siegel
    Sep 16, 2019

    1
    Varied terrain on Europa. Credit: NASA/JPL-Caltech/SETI Institute

    NASA/Europa Clipper annotated

    NASA’s Clipper mission to Jupiter’s second (of four) large moons, Europa, will perform at least 45 close flybys of its main target, monitoring its surface, subsurface ocean, and atmosphere for a series of signatures that could reveal information vital to assessing Europa as a location for potential habitability or biological activity within our own Solar System. (NASA/JPL-CALTECH)




    Is there life beyond Earth, even in our Solar System? This mission might be humanity’s best hope of finding it.

    The biggest question facing humanity might be, “Does life exists beyond Earth?”

    1
    When a planet transits in front of its parent star, some of the light is not only blocked, but if an atmosphere is present, filters through it, creating absorption or emission lines that a sophisticated-enough observatory could detect. If there are organic molecules or large amounts of molecular oxygen, we might be able to find that, too. It’s important that we consider not only the signatures of life we know of, but of possible life that we don’t find here on Earth. (ESA / DAVID SING)

    Planet transit. NASA/Ames

    Other solar systems might possess advanced or planet-altering biological activity, but simple life could exist right here.

    2
    Scanning electron microscope image at the sub-cellular level. While DNA is an incredibly complex, long molecule, it is made of the same building blocks (atoms) as everything else. To the best of our knowledge, the DNA structure that life is based on predates the fossil record. The longer and more complex a DNA molecule is, the more potential structures, functions, and proteins it can encode. (PUBLIC DOMAIN IMAGE BY DR. ERSKINE PALMER, USCDCP)

    In our own Solar System, eight different worlds might be home to unicellular life.

    3
    Among the moons in our Solar System, the largest are Ganymede and Titan (the only moons larger than a planet: Mercury), followed in size by Callisto, Io. the Moon, Europa, and Triton. Along with Pluto, Eris, the Sun and the major planets, these are the only worlds in the Solar System larger than 1,000 km in radius. (NASA, VIA WIKIMEDIA COMMONS USER BRICKTOP; EDITED BY WIKIMEDIA COMMONS USERS DEUAR, KFP, TOTOBAGGINS)

    Europa, among the Solar System largest moons, might experience the most life-friendly conditions.

    All life:

    harvests and metabolizes energy/resources,
    responds to external stimuli,
    grows and adapts,
    and reproduces.

    3
    Acidobacteria, like the example shown here, are likely some of the first photosynthetic organisms of all. They have no internal structure or membranes, loose, free-floating DNA, and are anoxygenic: they do not produce oxygen from photosynthesis. These are prokaryotic organisms that are very similar to the primitive life found on Earth some ~2.5–3 billion years ago. (US DEPARTMENT OF ENERGY / PUBLIC DOMAIN)

    While liquid oceans cover 70% of our surface, diminutive Europa has more water than planet Earth.

    4
    Based on the data collected by Galileo, the previous generation of NASA orbiter to study the Jovian system, we learned that Europa contains more water than all of planet Earth, combined, despite being much physically smaller and less massive in size. This water should exist in the liquid phase beneath the surface ice, providing a potential location for life to arise and thrive. (KEVIN HAND (JPL/CALTECH), JACK COOK (WOODS HOLE OCEANOGRAPHIC INSTITUTION), HOWARD PERLMAN (USGS))

    NASA/Galileo 1989-2003

    Beneath a thick layer of water-ice, Europa’s interior experiences high pressures and temperatures.

    5
    Scientists are all but certain that Europa has an ocean underneath its icy surface, but they do not know how thick this ice might be. This artist concept illustrates two possible cut-away views through Europa’s ice shell. In both, heat escapes, possibly volcanically, from Europa’s rocky mantle and is carried upward by buoyant oceanic currents, but the details will be different and will lead to different observable signatures for the instruments aboard NASA’s Clipper. (NASA/JPL/MICHAEL CARROLL)

    Nearby, massive Jupiter exerts tidal forces on Europa, heating its core while shearing and cracking its icy surface.

    The internal heat melts Europa’s pressurized ice, creating a deep, liquid ocean.

    6
    This cutaway of Jupiter’s 4th largest moon, Europa. shows the internal core and rocky mantle, heated by the tidal forces exerted by Jupiter, surrounded by a large, thick layer of water. Beneath the icy surface, once the pressure and temperature reach a critical level, the water becomes liquid, meaning there must be an ocean beneath this icy crust. (KELVINSONG / WIKIMEDIA COMMONS)

    Hydrothermal vents should line the seafloor: where energy gradients could enable life.

    7
    Deep under the sea, around hydrothermal vents, where no sunlight reaches, life still thrives on Earth. How to create life from non-life is one of the great open questions in science today, but if life can exist down here, perhaps undersea on Europa or Enceladus, there’s life, too. It will be more and better data, most likely collected and analyzed by experts, that will eventually determine the scientific answer to this mystery. (NOAA/PMEL VENTS PROGRAM)

    In 2023, a new NASA mission — the Europa Clipper — will investigate Europa for biosignatures.

    8
    Europa’s crust is largely made up of blocks, which scientists think once broke apart, fragmented, and ‘rafted’ their way into their current configuration. As Europa also possesses a magnetic field, the geologic data strongly supports the idea that Europa contains a deep subsurface ocean, with the reddish-brown areas (in assigned colors) showcasing non-ice material that is thought to result from geologic activity. (NASA/GALILEO/JPL/UNIVERSITY OF ARIZONA)

    This orbiter will utilize nine instruments to investigate Europa’s oceans and atmosphere.

    9
    NASA’s Clipper mission will undertake an orbital path that uses the gravitation of Jupiter and its other many moons to create a series of flybys that give global coverage of Europa under different seasonal and day/night conditions. Measuring time-variations in the results returned by the instruments will be crucial to uncovering all the potential bio-hints that Europa might have to offer. (NASA / JPL-CALTECH)

    Dozens of flybys will reveal their compositions, temperatures, depths, salinities, time-variations, etc.

    With life teeming beneath Earth’s Antarctic ices, Europa may be humanity’s best hope for discovering extraterrestrial life.

    10
    Scenes such as ice, stalactices, icebergs and liquid water are extrememly common in Antarctica. Sources of heat from beneath Earth’s surface create subsurface liquid water ‘lakes’ beneath the Antarctic ice, and living organisms exist and thrive in that environment. Perhaps, beneath the icy ocean of Europa, a similar story will emerge. (Delphine AURES/Gamma-Rapho via Getty Images)

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 10:09 pm on September 16, 2019 Permalink | Reply
    Tags: , , , , ,   

    From Fermi National Accelerator Lab: “Finding the missing pieces in the puzzle of an antineutrino’s energy” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    September 16, 2019
    Andrew Olivier

    Charged particles, like protons and electrons, can be characterized by the trails of atoms these particles ionize. In contrast, neutrinos and their antiparticle partners almost never ionize atoms, so their interactions have to be pieced together by how they break nuclei apart.

    But when the breakup produces a neutron, it can silently carry away a critical piece of information: some of the antineutrino’s energy.

    Fermilab’s MINERvA collaboration recently published a paper [Phys.Rev.D] to quantify the neutrons produced by antineutrinos interacting on a plastic target.

    FNAL MINERvA front face Photo Reidar Hahn

    The way antineutrinos change between their various types could help explain why the modern universe is dominated by matter. The most promising model of how this behavior relates particles and antiparticles depends on antineutrino energy. However, neutrons can leave holes in the puzzle of an antineutrino’s identity because they carry away energy and are produced in different quantities by neutrinos and antineutrinos. This MINERvA result is aimed at improving predictions of how neutrons could affect current and future neutrino experiments, including the international Deep Underground Neutrino Experiment, hosted by Fermilab.

    SURF-Sanford Underground Research Facility, Lead, South Dakota, USA


    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    3
    The MINERvA detector at Fermilab helps scientists analyze neutrino interactions with atomic nuclei. Photo: Reidar Hahn

    In this study, MINERvA looked for antineutrino interactions that produce neutrons. The antineutrino interactions that MINERvA studies look like one or more trails of ionized atoms all pointing back to a single nucleus. Unlike charged particles, neutrons can travel many tens of centimeters from an antineutrino interaction before being detected. So, the MINERvA collaboration characterized neutron activity as pockets of ionized atoms spatially isolated from both charged particle tracks and the interaction point.

    An antineutrino interaction can produce other types of neutral particles, which can fake a neutron interaction, and charged particles, which can confuse a neutron counting measurement by themselves ejecting neutrons from nuclei. In addition, when these charged particles have low momentum, they can end up in a mass of ionization too close to the interaction point to be counted separately that also masks evidence for neutral particles. So, neutrons can be counted more accurately in antineutrino interactions that produce few additional particles. MINERvA scientists used conservation of momentum calculations to avoid interactions that produced many charged particles.

    4
    This graphic illustrates a neutrino interaction in the MINERvA detector. The rectangular box highlights the spot where a neutrino interacted inside the detector. The square box just above it highlights the appearance of a neutron resulting from the neutrino interaction. Image: MINERvA

    Other experiments’ measurements of neutrons from antineutrinos have waited for each neutron to lose most of its energy before it can be counted. However, neutrons from MINERvA’s antineutrino sample have enough energy to knock other neutrons out of nuclei they collide with. This chain reaction changes both the original neutrons’ energies and the number of neutrons detected. This result focuses on signs of neutrons within tens of nanoseconds of an antineutrino interaction.

    By understanding neutron production in concert with MINERvA’s characterization of antineutrino interactions on many nuclei, future oscillation studies can quantify how undetected neutrons could affect their conclusions about the differences between neutrinos and antineutrinos.

    Andrew Olivier is a physicist at the University of Rochester and member of the MINERvA collaboration.

    See the full here.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 9:15 pm on September 16, 2019 Permalink | Reply
    Tags: 21st century alchemy, , , , , Plasmons   

    From Niels Bohr Institute: “Quantum Alchemy: Researchers use laser light to transform metal into magnet” 

    University of Copenhagen

    Niels Bohr Institute bloc

    From Niels Bohr Institute

    16 September 2019

    Mark Spencer Rudner
    Associate Professor
    Condensed Matter Physics
    Niels Bohr Institutet
    rudner@nbi.ku.dk

    Maria Hornbek
    Journalist
    The Faculty of Science
    maho@science.ku.dk
    +45 22 95 42 83

    CONDENSED MATTER PHYSICS: Pioneering physicists from the University of Copenhagen and Nanyang Technological University in Singapore have discovered a way to get non-magnetic materials to make themselves magnetic by way of laser light. The phenomenon may also be used to endow many other materials with new properties.

    1
    Mark Rudner, Niels Bohr Institute, University of Copenhagen

    2
    Asst Prof Justin Song Chien Wen

    The intrinsic properties of materials arise from their chemistry — from the types of atoms that are present and the way that they are arranged. These factors determine, for example, how well a material may conduct electricity or whether or not it is magnetic. Therefore, the traditional route for changing or achieving new material properties has been through chemistry.

    Now, a pair of researchers from the University of Copenhagen and Nanyang Technological University in Singapore have discovered a new physical route to the transformation of material properties: when stimulated by laser light, a metal can transform itself from within and suddenly acquire new properties.

    1

    “For several years, we have been looking into how to transform the properties of a matter by irradiating it with certain types of light. What’s new is that not only can we change the properties using light, we can trigger the material to change itself, from the inside out, and emerge into a new phase with completely new properties. For instance, a non-magnetic metal can suddenly transform into a magnet,” explains Associate Professor Mark Rudner, a researcher at the University of Copenhagen’s Niels Bohr Institute.

    He and colleague Justin Song of Nanyang Technological University in Singapore made the discovery that is now published in Nature Physics. The idea of using light to transform the properties of a material is not novel in itself. But up to now, researchers have only been capable of manipulating the properties already found in a material. Giving a metal its own ‘separate life’, allowing it to generate its own new properties, has never been seen before.

    By way of theoretical analysis, the researchers have succeeded in proving that when a non-magnetic metallic disk is irradiated with linearly polarized light, circulating electric currents and hence magnetism can spontaneously emerge in the disk.

    Researchers use so-called plasmons (a type of electron wave) found in the material to change its intrinsic properties. When the material is irradiated with laser light, plasmons in the metal disk begin to rotate in either a clockwise or counterclockwise direction. However, these plasmons change the quantum electronic structure of a material, which simultaneously alters their own behavior, catalyzing a feedback loop. Feedback from the plasmons’ internal electric fields eventually causes the plasmons to break the intrinsic symmetry of the material and trigger an instability toward self-rotation that causes the metal to become magnetic.

    Technique can produce properties ‘on demand’

    According to Mark Rudner, the new theory pries open an entire new mindset and most likely, a wide range of applications:

    “It is an example of how the interaction between light and material can be used to produce certain properties in a material ‘on demand’. It also paves the way for a multitude of uses, because the principle is quite general and can work on many types of materials. We have demonstrated that we can transform a material into a magnet. We might also be able to change it into a superconductor or something entirely different,” says Rudner. He adds:

    “You could call it 21st century alchemy. In the Middle Ages, people were fascinated by the prospect of transforming lead into gold. Today, we aim to get one material to behave like another by stimulating it with a laser.”

    Among the possibilities, Rudner suggests that the principle could be useful in situations where one needs a material to alternate between behaving magnetically and not. It could also prove useful in opto-electronics – where, for example, light and electronics are combined for fiber-internet and sensor development.

    The researchers’ next steps are to expand the catalog of properties that can be altered in analogous ways, and to help stimulate their experimental investigation and utilization.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings


    Stem Education Coalition

    Niels Bohr Institute Campus

    Niels Bohr Institute (Danish: Niels Bohr Institutet) is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

    The Institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institute.[1] Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.[2]

    During the 1920s, and 1930s, the Institute was the center of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

    On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institute.

    The University of Copenhagen (UCPH) (Danish: Københavns Universitet) is the oldest university and research institution in Denmark. Founded in 1479 as a studium generale, it is the second oldest institution for higher education in Scandinavia after Uppsala University (1477). The university has 23,473 undergraduate students, 17,398 postgraduate students, 2,968 doctoral students and over 9,000 employees. The university has four campuses located in and around Copenhagen, with the headquarters located in central Copenhagen. Most courses are taught in Danish; however, many courses are also offered in English and a few in German. The university has several thousands of foreign students, about half of whom come from Nordic countries.

    The university is a member of the International Alliance of Research Universities (IARU), along with University of Cambridge, Yale University, The Australian National University, and UC Berkeley, amongst others. The 2016 Academic Ranking of World Universities ranks the University of Copenhagen as the best university in Scandinavia and 30th in the world, the 2016-2017 Times Higher Education World University Rankings as 120th in the world, and the 2016-2017 QS World University Rankings as 68th in the world. The university has had 9 alumni become Nobel laureates and has produced one Turing Award recipient

     
  • richardmitnick 8:53 pm on September 16, 2019 Permalink | Reply
    Tags: , , , , , the most massive neutron star yet J0740+6620   

    From PBS NOVA: “Astronomers may have just detected the most massive neutron star yet” 

    From PBS NOVA

    September 16, 2019
    Katherine J. Wu

    1
    An artist’s impression of the pulse from a neutron star being delayed by a white dwarf passing between the neutron star and Earth. Image Credit: BSaxton, NRAO/AUI/NSF

    1

    The sun at the center of our solar system is a big-bodied behemoth, clocking in at more than 4 nonillion pounds (in the U.S., that’s 4 followed by 30 zeros).

    Now, multiply that mass by 2.14, and cram it down into a ball just 15 miles across. That’s an absurdly dense object, one almost too dense to exist. But the key word here is “almost”—because a team of astronomers has just found one such star.

    The newly discovered cosmic improbability, reported today in the journal Nature Astronomy, is a neutron star called J0740+6620 that lurks 4,600 light-years from Earth. It’s the most massive neutron star ever detected, and is likely to remain a top contender for that title for some time: Much denser, researchers theorize, and it would collapse into a black hole.

    Both neutron stars and black holes are stellar corpses—the leftover cores of stars that die in cataclysmic explosions called supernovae. The density of these remnants dictates their fate: The more mass that’s stuffed into a small space, the more likely a black hole will form.

    Neutron stars are still ultra-dense, though, and astronomers don’t have a clear-cut understanding of how matter behaves within them. Extremely massive neutron stars like this one, which exist tantalizingly close to the black hole tipping point, could yield some answers, study author Thankful Cromartie, an astronomer at the University of Virginia, told Ryan F. Mandelbaum at Gizmodo.

    Cromartie and her colleagues first detected J0740+6620, which is a type of rapidly rotating neutron star called a millisecond pulsar, with the Green Bank telescope in West Virginia. The name arises from the way the spinning star’s poles emit radio waves, generating a pulsing pattern that mimics the sweeping motion of a lighthouse beam.

    During their observations, the researchers noted that J0740+6620 is locked into a tight dance with a white dwarf—another kind of dense stellar remnant. The two bodies orbit each other, forming what’s called a binary. When the white dwarf passes in front of the pulsar from our point of view, it forces light from J0740+6620 to take a slightly longer path to Earth, because the white dwarf’s gravity slightly warps the space around it. The team used the delay in J0740+6620’s pulses to calculate the mass of both objects.

    Previous measurements from the Laser Interferometer Gravitational-Wave Observatory (LIGO) suggest that the upper limit for a neutron star’s mass is about 2.17 times that of the sun—a figure that’s just a smidge above J0740+6620’s estimated heft. But with future observations, that number could still change.

    MIT /Caltech Advanced aLigo

    Harshal Gupta, NSF program director for the Green Bank Observatory, called the new paper “a very solid effort in terms of astronomy and the physics of compact objects,” Mandelbaum reports.

    “Each ‘most massive’ neutron star we find brings us closer to identifying that tipping point [when they must collapse],” study author Scott Ransom, an astronomer at the National Radio Astronomy Observatory, said in a statement. “The orientation of this binary star system created a fantastic cosmic laboratory.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NOVA is the highest rated science series on television and the most watched documentary series on public television. It is also one of television’s most acclaimed series, having won every major television award, most of them many times over.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: