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  • richardmitnick 11:43 am on September 7, 2019 Permalink | Reply
    Tags: A resulting gravito-magnetic field analogous to the magnetic field surrounding the two poles of a magnet would explain the alignment of the jets with the source’s north-south axis of rotation., Albert Einstein’s equations of gravity and James Clerk Maxwell’s equations of electromagnetism., Astronomers expect that a new satellite (LARES 2) to be launched at the end of 2019 will with data from LAGEOS give an accuracy of 0.2%., Astrophysicists have already taken gravito-magnetism on board., , But how far can such mathematical analogies be pushed? Is “gravito-magnetic induction” real? If it is it should show up as a tiny wobble in the orbit of satellites., Cosmos Magazine, For frame-dragging the best agreement with GR has been within 0.2%, Gravito-electromagnetism, In some ways mathematics is like literature. It has its own definitions and grammatical rules – although unfortunately these are the bane of too many students’ lives., It suggests a mechanism to explain the mysterious jets of gas that have been observed spewing out of quasars and active galactic nuclei., Making physical analogies is fundamental in the process of physics because it helps physicists to imagine new physical phenomena., , , Rotating supermassive black holes at the heart of these cosmic powerhouses would produce enormous frame-dragging and geodetic effects., Simpler versions that work with an accuracy of 5%., The intriguing mathematical analogy between the equations of Newtonian gravity and Coulomb’s law of electrostatics., The prediction of a new force: “gravito-magnetism”, The same is true of mathematical analogies applied to physical reality – and especially of the interplay between mathematical and physical analogies., Today this so-called “gravito-electromagnetism” or GEM for short is generally treated mathematically via the “weak field” approximation to the full GR equations – simpler versions that work   

    From COSMOS Magazine: “Introducing the amazing concept of gravito-electromagnetism” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    05 September 2019
    Robyn Arianrhod

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    Mathematician and poet James Clerk Maxwell. Credit SIR GODFREY KNELLER / GETTY IMAGES / (BACKGROUND) SOLA

    In some ways, mathematics is like literature. It has its own definitions and grammatical rules – although unfortunately these are the bane of too many students’ lives. Which is a great pity, because when used elegantly and clearly, mathematical language can help readers to see things in entirely new ways. Take analogies, for example. They’re obviously powerful in literature – who doesn’t thrill to a creative, well-aimed metaphor? But they can be even more powerful in mathematical physics.

    Making physical analogies is fundamental in the process of physics, because it helps physicists to imagine new physical phenomena. We still speak of the “flow” of an electric “current”, using liquid metaphors that physicists coined before they knew that electrons existed. On the other hand, the old concept of “ether” – a hypothetical light-carrying medium analogous to water or air – has long passed its use-by date. Physical analogies can be creative and useful, but sometimes they can lead one astray.

    The same is true of mathematical analogies applied to physical reality – and especially of the interplay between mathematical and physical analogies. An analogy that has tantalised mathematicians and physicists for a century, and which is still a hot if much-debated topic, is that between Albert Einstein’s equations of gravity and James Clerk Maxwell’s equations of electromagnetism. It’s led to an exciting new field of research called “gravito-electromagnetism” – and to the prediction of a new force, “gravito-magnetism”.

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    Diagram regarding the confirmation of Gravitomagnetism by Gravity Probe B. Gravity Probe B Team, Stanford, NASA

    The surprising idea of comparing gravity and electromagnetism – two entirely different kinds of phenomena – began with the intriguing mathematical analogy between the equations of Newtonian gravity and Coulomb’s law of electrostatics. Both sets of equations have exactly the same inverse-square form.

    In 1913, Einstein began exploring the much more complex idea of a relativistic gravitational analogue of electromagnetic induction – an idea that was developed by Josef Lense and Hans Thirring in 1918. They used Einstein’s final theory of general relativity (GR), which was published in 1916.

    Today this so-called “gravito-electromagnetism”, or GEM for short, is generally treated mathematically via the “weak field” approximation to the full GR equations – simpler versions that work well in weak fields such as that of the earth.

    It turns out that the mathematics of weak fields includes quantities satisfying equations that look remarkably similar to Maxwell’s. The “gravito-electric” part can be readily identified with the everyday Newtonian downward force that keeps us anchored to the earth. The “gravito-magnetic” part, however, is something entirely unfamiliar – a new force apparently due to the rotation of the earth (or any large mass).

    It’s analogous to the way a spinning electron produces a magnetic field via electromagnetic induction, except that mathematically, a massive spinning object mathematically “induces” a “dragging” of space-time itself – as if space-time were like a viscous fluid that’s dragged around a rotating ball. (Einstein first identified “frame-dragging”, a consequence of general relativity elaborated by Lense and Thirring.)

    But how far can such mathematical analogies be pushed? Is “gravito-magnetic induction” real? If it is, it should show up as a tiny wobble in the orbit of satellites, and – thanks also to the “geodetic” effect, the curving of space-time by matter – as a change in the direction of the axis of an orbiting gyroscope. (The latter is analogous to the way a magnetic field generated by an electric current changes the orientation of a magnetic dipole.)

    Finally, after a century of speculation, answers are unfolding. Independent results from several satellite missions – notably Gravity Probe B, LAGEOS, LARES, and GRACE – have confirmed the earth’s geodetic and frame-dragging effects to varying degrees of precision.


    NASA/Gravity Probe B

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    LAGEOS satellite, courtesy of NASA

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    The LARES Satellite. Italian Space Agency

    NASA/ German Research Centre for Geosciences (GFZ) Grace-FO satellites

    For frame-dragging, the best agreement with GR has been within 0.2%, with an accuracy of 5%, but astronomers expect that a new satellite (LARES 2), to be launched at the end of 2019, will, with data from LAGEOS, give an accuracy of 0.2%.

    More accurate results will provide more stringent tests of GR, but astrophysicists have already taken gravito-magnetism on board. For instance, it suggests a mechanism to explain the mysterious jets of gas that have been observed spewing out of quasars and active galactic nuclei. Rotating supermassive black holes at the heart of these cosmic powerhouses would produce enormous frame-dragging and geodetic effects. A resulting gravito-magnetic field analogous to the magnetic field surrounding the two poles of a magnet would explain the alignment of the jets with the source’s north-south axis of rotation.

    Making analogies is a tricky business, however, and there are some interpretive anomalies still to unravel. To take just one example, questions remain about the meaning of analogical terms such as gravitational “energy density” and “energy current density”. Things are perhaps even more problematic – or interesting – from the mathematical point of view.

    For example, there is another, purely mathematical analogy between Einstein’s and Maxwell’s equations, which gives rise to a very different analogy from the GEM equations. To put it briefly, it’s a comparison between the so-called Bianchi identities in each theory.

    The existence of two (and in fact several) such different mathematical analogies between the equations of these two physical phenomena is incredibly suggestive of a deeper connection. At present, though, there are some apparent physical inconsistencies between the “electric” and “magnetic” parts in each mathematical approach.

    Still, the formal analogies are useful in helping mathematicians find intuitively familiar ways to think about the formidable equations of GR. And there’s always the tantalising possibility that this approach will prove as physically profound as the prediction of gravito-magnetism.

    See the full article here .


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  • richardmitnick 9:48 am on September 4, 2019 Permalink | Reply
    Tags: An analysis of global data should shatter gender stereotypes that suggest females have an inferior grasp of STEM (science; technology; engineering ;and math) topics., Cosmos Magazine, Females are better than males at sustaining their performance on longer tests involving maths and science hence reducing the gender gap., Gender considered for test taking   

    From COSMOS Magazine: “Girls are just as good at STEM, study finds” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    04 September 2019
    Natalie Parletta

    The proof lies in longer test duration.

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    Females students do better on longer tests because of their ability to sustain performance, research suggests. Caiaimage/Chris Ryan, via Getty Images.

    An analysis of global data should shatter gender stereotypes that suggest females have an inferior grasp of STEM (science, technology, engineering and maths) topics.

    The study, published in the journal Nature Communications, shows that females are better than males at sustaining their performance on longer tests involving maths and science, hence reducing the gender gap.

    This unexpected discovery was made by researchers Pau Balart, from the University of Illes Balears in Spain, and Matthijs Oosterveen from the Erasmus University Rotterdam in the Netherlands.

    They were “fascinated” by research that found student performance drops during test-taking, says Balart, and thought gender differences could yield interesting insights, especially if combined with already known differences in cognitive domains.

    This notion offered an opportunity to challenge beliefs like that of Oxford University dons.

    After giving females 15 minutes longer on maths and computer science exams, the dons declared a commonly held view to The Telegraph that “female candidates might be more likely to be adversely affected by time pressure”.

    Balart and Oosterveen proposed another explanation: “female students might make better use of the extra time on the test because of their ability to sustain performance”.

    Putting this to the test, they analysed data collected every three years from 2006 to 2015 in 74 countries for the Programme for International Student Assessment (PISA), a standardised assessment of 15-year-old students’ performance in reading, maths and science.

    Results on early test items aligned with previous findings that girls do better with reading and boys with maths and science.

    But when comparing each gender’s scores at different stages of test taking, girls indeed showed less decline in accuracy over time on all the tests.

    Although boys had an initial advantage in maths and science, the authors write, “there was not a single country in which they were significantly better able to sustain their performance during the test.

    “This finding suggests that longer cognitive tests exacerbate the gender gap in reading and shrink it in math and science.”

    In 20% of the countries, the gender gap completely disappeared or even switched after two hours of test duration.

    Notably, Balart says girls’ superior ability to sustain performance “exists in all waves [of the PISA], and though the size and statistical significance varies somewhat across countries, given the results it is fair to say that this gender difference exists worldwide”.

    He adds that he was surprised by “the robustness and pervasiveness of this gender difference”.

    Other possible explanations recorded by the database – non-cognitive skills, test-taking strategies and test effort – did not influence the results.

    To find out whether girls’ ability to sustain performance could help nullify perceived gender differences in maths, the researchers then analysed another database compiled for a meta-analysis of more than 400 maths tests.

    By factoring in varying test length, they confirmed that girls did better on longer maths tests, closing the gender gap. As predicted, this was not explained by gender differences in dealing with time pressure.

    Therefore, the “most notable implication of this study consists of emphasising a female strength in test taking,” says Balart, one that “has largely been ignored and that deserves visibility and recognition”.

    “The research is yet another indication that cognitive tests do not only measure cognitive skills (how smart someone is), but that they also measure noncognitive skills (like perseverance and test motivation),” he adds.

    He hopes the findings offer a counterbalance to gender stereotypes in maths and sciences that are reinforced by comments about dealing with time pressure, suggesting a female weakness.

    Instead, the difference “could be framed in terms of rewarding a valuable skill in which female students perform relatively better”.

    Although Balart cautions that test validity should be considered before changing their length, longer tests offer a valuable tool for policies seeking to achieve gender equality in STEM course enrolment and career choices.

    See the full article here .


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  • richardmitnick 10:53 am on August 6, 2019 Permalink | Reply
    Tags: , , , Cosmos Magazine, , , QUT University, The Great Barrier Reef   

    From COSMOS Magazine and QUT University: “Citizen scientists and the Great Barrier Reef” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    and

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    QUT University

    06 August 2019

    QUT researchers are inviting you to help with vital work.

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    Researchers are seeking help to save one of the world’s great marine environments. Jeff Hunter/Getty Images

    If news bulletins explaining how climate change has devastated parts of Australia’s Great Barrier Reef leave you feeling impotent and depressed, maybe getting involved in one of several citizen science projects up there could help.

    Researchers from Brisbane-based university QUT run several programs that are turning everyone from secondary school kids to tourists into marine scientists.

    Statistician Erin Peterson, for example, designed the Virtual Reef Diver project to drive a new approach to monitoring and managing the Great Barrier Reef.

    Members of the public can log on to the website and work through the collection of photographs, classifying the images as they go.

    Less “virtual” divers and snorkellers can submit underwater images they have taken while out on the Reef for others to classify.

    This work is vital.

    “The main challenge that we were trying to address is that the Great Barrier Reef is huge,” says Peterson. “It costs a lot to monitor it all.”

    “But there are more than 65 different organisations out there collecting data on the reef – specifically images – all the time.

    “Plus we have all these citizens out snorkelling or scuba diving, and everybody has an underwater camera now.

    “And so the idea was, can we bring together these image-based data from all these different sources, and learn more about what’s going on to get an estimate of coral cover.”

    Once the data is in and classified, data scientists such as Peterson design statistical models to create a predictive map across the whole of the Great Barrier Reef. Thanks to ordinary lay people, the information is as up-to-date as possible.

    Meanwhile, reef researcher Brett Lewis, at QUT’s Science and Engineering Faculty, has his sights set not on the Great Barrier Reef but its smaller cousins in Moreton Bay, near Brisbane.

    His work focusses on reefs in inner Moreton Bay to see how they cope with climate stress, and what that can tell us about the larger ecosystem to the north.

    Apart from climate, the bay reefs face challenges from sediments spilling from the Brisbane River. This is where Lewis’s work holds relevance for studying the effects of dredging on the Great Barrier Reef.

    “One of the easiest things for us to do, and one of the most beneficial for the local area, is to understand how the corals are surviving sedimentation from the Brisbane River and this turbid environment,” he says. “And I have the techniques to be able to carry this out.”

    For much of his work, Lewis uses time-lapse videography and other visual media to capture, in detail, the changes in corals.

    When Iona College in the Brisbane bayside suburb of Wynnum reached out to see if he would help the students develop a marine science project, he said “yes” immediately.

    To start with, Lewis gave students in years 9, 10 and 11 a crash course in scientific observation. Then, after helping them set up aquariums with corals, he gave them a project: create time-lapse videos of how corals deal with different forms of sedimentation, coarse and fine.

    Not only did students get to run the experiments, they got to report on the results, learning to present at conferences.

    “I wanted them to see the impact that their research can have rather than me saying that their research is going to have impact,” says Lewis. “They can visualise it for themselves and see that, yeah, it’s important that we also communicate.”

    QUT’s Matthew Dunbabin and his team keep watch on the Great Barrier Reef – and other reefs around the world – using technology. He and his team last year launched RangerBot, an underwater drone that can monitor marine health and even take direct action – by identifying and destroying the devastating crown-of-thorns starfish.

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    RangerBot’s high-tech vision system allows it to “see” under water, a system that helped it win the 2016 Google Impact Challenge People’s Choice prize when it was still under development.

    Having “trained” the RangerBot to take on the crown-of-thorns, QUT researchers are teaching it new tricks. In April they took it to the Philippines to help in reseeding reefs destroyed by dynamite fishing.

    The project won Dunbabin and Southern Cross University’s Peter Harrison the Great Barrier Reef Foundation’s $300,000 Out of the Blue Box Reef Innovation Challenge.

    “We’re looking at a large-scale spreading of the coral spawn,” Dunbabin says.

    “At the moment it’s a manual task, but we attach different payloads that hold bags of concentrated coral spawn after they’ve [been] reared and fertilised.”

    Once that project has been assessed, Dunbabin will head back to the Great Barrier Reef for a similar project at the end of the year.

    And there’s room in RangerBot’s work for the citizen scientist, too.

    “We’ve set it up so that it can be used as a citizen science program,” he says. “We have a citizen science portal where we upload data that’s been collected and lay scientists can help identify crown-of-thorns starfish, helping to verify what the robot thought it saw.”

    They are also working on another project they call the “coral point count” to engage the public where they can upload their own data from their own observations in a similar way to the Virtual Reef project.

    “We’ve developed that with schools,” Dunbabin says. “We were lucky enough to get some money from the Lord Mayor’s Charitable Fund in Melbourne and the Dalio Foundation to engage high schools and other stakeholders.”

    “High schools where students studied marine science were asked to use the technology and give us feedback on what they liked and how we can make it a useful tool.

    “So they actually helped guide the development of the interface for the robot and got an understanding of the technology, and used it as part of that assessment,” he said.

    Professor Dunbabin says it is vital to keep people engaged so they don’t give up hope of keeping the reef vibrant.

    “I think everybody has a role that can help protect the Reef,” he says. “People can actually be part of the science, where they’re analysing the data that helps them contribute to the protection of the reef.”

    See the full article here .


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    Please help promote STEM in your local schools.

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  • richardmitnick 9:28 am on August 2, 2019 Permalink | Reply
    Tags: "LightSail away", , , , , , Cosmos Magazine, The Planetary Society   

    From The Planetary Society via COSMOS Magazine: “LightSail away” 

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    From The Planetary Society

    via

    Cosmos Magazine bloc

    COSMOS Magazine

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    LightSail 2 during deployment, with Baja California and Mexico visible in the background. Its dual 185-degree fisheye camera lenses can each capture more than half of the sail. The Planetary Society.

    A small non-profit organisation has achieved a space-travel feat dreamed about for more than 40 years: proving that it is possible to manoeuvre a spacecraft in Earth orbit using only the power of sunbeams.

    Seven weeks ago, The Planetary Society, which has 50,000 members in 109 countries, launched a tiny, five-kilogram spacecraft into orbit, aboard a SpaceX Heavy Falcon rocket that also carried two dozen spacecraft for the US Air Force.

    From there, the spacecraft, called LightSail 2, was delivered to an orbit about 720 kilometres above the Earth.

    After preliminary tests, it deployed a boxing-ring-sized sheet of reflective Mylar film, which, since then, it has been using to “sail” on the pressure of sunlight.

    As far back as 1977, astronomer Carl Sagan – The Planetary Society’s founder – was promoting light sails as a way of propelling spacecraft.

    They work because the photons that comprise light, even though they are massless, possess momentum, causing them to exert a gentle pressure on whatever object the light falls on. That pressure can be doubled by reflecting the light with a mirror, which is why LightSail 2 uses a silvery film for its sail.

    Sagan’s dream was to use a big lightsail to propel a big spacecraft.

    “Back in the 1970s,” says The Planetary Society’s CEO, science educator Bill Nye, “the proposal was to have a solar sail a kilometre on a side that would catch up with comet Halley [after it last passed close to the Sun in 1986].”

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    The idea was quickly abandoned due to budget concerns and the sense that it was impractical. Revived interest, however, came from the development of miniaturised spacecraft known as CubeSats, which are constructed in blocks measuring 10 × 10 × 11.35 centimetres. (LightSail 2 is built in three of these blocks).

    Not only are these inexpensive to launch, their low mass makes them perfect for light sailing. Instead of needing a 100-hectare lightsail, like Sagan’s comet-chaser proposal, LightSail 2 only needs a 32-square-metre sail.

    The spacecraft’s small size also makes it easy to manoeuvre – important, because its operations require the orientation of its lightsail to be changed rapidly as it circles the Earth, like a sailboat tacking in changing winds.

    The results were dramatic, says Bruce Betts, the project’s chief scientist and program manager. In the eight days since the light sail was deployed, the spacecraft has raised its orbit’s apogee (the point at which it is most distant from the Earth) by 1.7 kilometres.

    “Our biggest change was a little over 900 metres, three days ago,” project manager David Spencer, an associate professor of aeronautics and astronautics at Purdue University, Indiana, told a press conference.

    LightSail 2 isn’t designed to do anything other than test the ability to use lightsails to manoeuvre. “This has been a demonstration mission all along,” says Jennifer Vaughan, The Planetary Society’s COO.

    But its success has important applications. NASA has a six-CubeSat near-Earth asteroid (NEA) mission, called NEA Scout, scheduled for launch sometime in 2020, which will also use light-sail propulsion.

    “We’ve got an agreement to share technologies and findings,” Spencer says. “We really look forward to them carrying solar sailing technology to the next level.”

    NEA Scout’s principal investigator, Les Johnson of NASA’s Marshall Spaceflight Centre, Huntsville, Alabama, agrees.

    “We are all solar sailors, wanting to achieve the same goals,” he told Cosmos shortly before LightSail 2 launched.

    And that might just be the beginning. Because lightsails don’t require fuel – and can therefore never run out of it – they are ideal for long-term missions, especially those in which spacecraft might have to do a lot of low-acceleration manoeuvring.

    For example, Nye says, they could be used to position a spacecraft between the Earth and the Sun, where it could provide as much as four to six hours of advance warning of dangerous bursts of solar radiation heading our way. Or, such a spacecraft could look outward, seeking out previously unknown asteroids that might pose a risk to the Earth.

    “Solar sails are uniquely suited to positioning themselves, station keeping, in orbits closer to the Sun than the Earth’s orbit,” Nye says.

    They can also be used to hold spacecraft in orbits around the Earth that are not otherwise stable, such as one that puts a satellite permanently above one of the Earth’s poles. Or, they can be used for long missions to multiple asteroids, the Outer Solar System, or even to other stars.

    With a normal spacecraft, Nye says, the fuel eventually runs out. “This fuel never runs out.”

    Meanwhile, LightSail 2’s mission isn’t over. “We’re still working to improve sail control,” Spencer says.

    The short-term goal, he says, will be to continue working to raise the spacecraft’s apogee. But the manner in which that is being done has the side effect of lowering the spacecraft’s perigee (its closest approach to the Earth).

    And, even though it’s 700 kilometres above the Earth’s surface, there’s enough of our planet’s tenuous exosphere up there to exert drag on such a lightweight spacecraft. “As perigee moves lower, the atmosphere is going to cause more drag, to the point where it’s going to be impossible for us to overcome that drag,” Spencer says.

    It would be possible, he adds, to employ different sailing techniques to raise the spacecraft’s perigee, along with its apogee, but that wasn’t the goal of the mission. “It’s certainly possible from a physics standpoint to do that, but that’s not in our near-term plan,” he says.

    Instead, LightSail 2 will then use its sail to study the drag of the far-outer atmosphere, until the spacecraft eventually falls back to Earth and burns up.

    Meanwhile, Nye says that in addition to its scientific objectives, the mission has achieved to other important goals.

    First, it was conducted at about “one-twentieth” the cost that would have been incurred by a “regular” space agency like NASA.

    Sure, more money would have been nicer – if for no other reason than to allow the control team to talk to the spacecraft throughout its orbit, rather than just when it was above one of their few tracking stations. “But nevertheless, we were able to pull it off,” Nye says.

    But more importantly, he says only days after the anniversary of the first Apollo Moon landing, “it shows, once again, that space exploration brings out the best in us.”

    See the full article here .

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    3

    In 1980, Carl Sagan, Louis Friedman, and Bruce Murray founded The Planetary Society. They saw that there was enormous public interest in space, but that this was not reflected in government, as NASA’s budget was cut again and again.

    Today, The Planetary Society continues this work, under the leadership of CEO Bill Nye, as the world’s largest and most influential non-profit space organization. The organization is supported by over 50,000 members in over 100 countries, and by hundreds of volunteers around the world.

    Our mission is to empower the world’s citizens to advance space science and exploration. We advocate for space and planetary science funding in government, inspire and educate people around the world, and develop and fund groundbreaking space science and technology.

    We introduce people to the wonders of the cosmos, bridging the gap between the scientific community and the general public to inspire and educate people from all walks of life.

    We give every citizen of the planet the opportunity to make their voices heard in government and effect real change in support of space exploration.

    And we bring ordinary people directly to the frontier of exploration as we crowdfund innovative and exciting space technologies.

     
  • richardmitnick 9:06 pm on May 27, 2019 Permalink | Reply
    Tags: , , Cosmos Magazine, DNA functions,   

    From COSMOS Magazine: “Autism linked to ‘junk’ DNA mutations” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    28 May 2019
    Andrew Masterson

    1
    Almost all DNA is non-coding, but research shows it is certainly not ‘junk’. Credit Anthony Harvie/Getty Images

    Mutations in so-called “junk” DNA have been tied to the development of autism (ASD) in children who do not have parents or siblings with the condition.

    The research, published in the journal Nature Genetics, provides an important piece of information in the quest to understand ASD, but also has wider significance.

    “This is the first clear demonstration of non-inherited, non-coding mutations causing any complex human disease or disorder,” says lead researcher Olga Troyanskaya of the US Flatiron Institute’s Centre for Computational Biology.

    Less than 2% of human DNA codes for the proteins that enable the critical functions of metabolism. The remaining 98% used to be thought of as effectively ballast, characterised as makeweight “junk”.

    Today, the label is recognised as a misnomer, and has been largely replaced by the term “non-coding”. Research [NIH] has shown that at least some of it plays very important roles in regulating the activity of genes – switching them on and off, and variously enhancing or dampening protein-coding activity.

    Previous studies have tied about 30% of autism cases in families with no prior history of the condition – so-called “simplex” cases – to mutations in particular coding genes.

    Using a machine-learning approach, Troyanskaya and colleagues analysed the genomes of 1790 people, comprising simplex autism cases and their families. Their model was trained to predict how any given DNA sequence would affect gene expression.

    The analysis revealed that cases linked to mutations in non-coding DNA should be of the same magnitude as those tied to coding DNA changes.

    The approach enables the identification of particular targets within the non-coding DNA which can now be the subject of more intense and focussed research.

    A computational biologic approach to DNA function, the researchers say, opens up a broad range of possible avenues for the understanding of conditions driven by genetic function.

    “This enables a new perspective on the cause of not just autism, but many human diseases,” says co-author Jian Zhou.

    See the full article here .


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  • richardmitnick 8:35 am on May 13, 2019 Permalink | Reply
    Tags: , , Cosmos Magazine, Potassium   

    From COSMOS Magazine: “Race for potassium batteries hots up” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    13 May 2019
    Phil Dooley

    Research aims to solve problems arising with potential lithium rival.

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    Mounds of potassium waste from a salt mine in the town of Soligorsk, some 140 kilometres south from Minsk, in Belarus. Credit: SERGEI GAPON/AFP/Getty Images

    Battery technology based on potassium could be the key to storing energy from renewables, according to a team of scientists from Wollongong University in Australia.

    2

    Currently lithium ion batteries are widely used because of their high energy density, but, because lithium is a relatively rare element, mining costs make them expensive.

    As an alternative, potassium, which is one of the Earth’s most abundant elements, could become the basis for a large-scale power storage, says Zaiping Guo, one of the authors of a review paper in the journal Science Advances.

    “Potassium is a rechargeable with huge potential, and has theoretically cheaper performance compared with lithium,” she says.

    The global market for lithium batteries was worth $25 billion in 2017, driven by technologies that require low-weight energy storage, such as electric cars and electronic devices.

    Potassium batteries are unlikely to reach the same energy density, because it is a heavier atom than lithium. However, it may succeed as a stationary large-scale storage method, coupled to intermittent renewable energy sources.

    “For a more sustainable society we need energy storage devices,” Guo says.

    “Compared with other storage options, such as super-capacitors or fuel cells, batteries are the most mature and easy to apply.”

    Even so, she estimates it will take 10 to 20 years before the potassium-based technology matures enough to close the gap on lithium.

    One of the major obstacles in creating an efficient potassium battery is the sluggish movement of large potassium ions through a solid electrode.

    Secondly, as the ions enter the electrode during the electrical reactions, their size causes the electrodes to swell, then shrink again as the reverse reaction occurs when the battery finishes charging and starts to discharge.

    It’s a challenge to develop an electrode material that can survive such repeated size change, but the team points out that nanotechnology could provide answers.

    Clusters of nanoparticles similar to bunches of grapes can withstand repeated size changes. Nanostructures with high surface areas could also remove the need for the potassium ions to penetrate far in to the electrode: various researchers have investigated [NCBI] structures with large surface areas.

    The structures have names such as nanotubes, nanofibres and even nanoroses.

    To complicate the situation, potassium is prone to other, less welcome reactions, which the nanomaterials can actually promote. However, careful choice of a material for the electrodes can help control these unwanted processes, for example by adding atoms of fluorine, oxygen, boron or sulfur to the carbon mix.

    Unwanted reactions are also a problem in the electrolyte – the conductive solution that allows potassium ions to flow between the two electrodes. For example, the potassium can deposit into intricate tree-shaped crystals called dendrites, which can cause a short-circuit within the battery.

    Guo points out that choice of solvent and use of additives can address these reactions. But it’s a balance, because the most effective solvents are organic, and therefore flammable. Alongside the tendency of potassium batteries to get hot, this is a safety issue that needs consideration.

    The advent of powerful computer modeling will help solve such issues, say the authors. Although there a number of obstacles, they conclude that potassium battery technology is “emerging as a great candidate for large-scale energy storage”.

    See the full article here .


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  • richardmitnick 11:03 am on March 19, 2019 Permalink | Reply
    Tags: "Quantum tunnelling is instantaneous researchers find", Cosmos Magazine, , Griffiths’ Australian Attosecond Science Facility,   

    From Griffith University via COSMOS Magazine: “Quantum tunnelling is instantaneous, researchers find” 

    Griffith U bloc

    From Griffith University

    via

    Cosmos Magazine bloc

    COSMOS Magazine

    19 March 2019
    Alan Duffy

    Physicists establish that electrons waste no time bashing through a barrier.

    1
    A diagrammatic representation of quantum tunnelling. Normaals/Getty Images

    Researchers have found that electrons passing through solid matter in a quantum process known as “tunnelling” do so instantaneously.

    The finding, led by scientists from Australia’s Griffith University, contradicts previous experiments [Nature] that suggested a degree of time elapses between the start and finish of a tunnelling event.

    The work is detailed in a paper in the journal Nature.

    Quantum tunnelling is one of the more bizarre differences between our everyday, classical world and the surprising realm of quantum mechanics.

    “If you lean on a wall, that wall pushes back in force so that you don’t go through it,” co-author Robert Sang says.

    “But when you go down to the microscopic level, things behave quite differently. This is where the laws of physics change from classical to quantum.”

    A particle in the quantum world actually can pass through that wall. The experimental question was, how long does it take to transition through a given obstacle – in this case, the electric barrier potential of a hydrogen atom.

    “We use the simplest atom, atomic hydrogen, and we’ve found that there’s no delay in what we can measure,” says Sang.

    The Nature paper is the culmination of a three-year international project, in which the team shot a hydrogen atom and its lone electron with an enormously powerful, ultra-fast laser contained in Griffiths’ Australian Attosecond Science Facility. The laser was circularly polarised, meaning that it imparted a rotation to an emitted electron.

    That resulting rotation in the electron’s “phase” could then be measured as if it were a clock hand ticking around – or in this case, more precisely, an atto-clock.

    “There’s a well-defined point where we can start that interaction, and there’s a point where we know where that electron should come out if it’s instantaneous,” explains Sang.

    “So anything that varies from that time we know that it’s taken that long to go through the barrier. That’s how we can measure how long it takes.

    “It came out to agree with the theory within experimental uncertainty being consistent with instantaneous tunnelling.”

    The precision of the clock to measure the tunnelling event was driven by the ultra-fast pulse of light in the attosecond laser – just a billionth of a billionth of a second long. The energy emitted by the laser during such a tiny amount of time is greater than that of the entire US power grid.

    Sang notes about the attosecond timescale that “it’s hard to appreciate how short that is, but it takes an electron about a hundred attoseconds to orbit a nucleus in an atom”.

    Tunnelling may be an unfamiliar effect in our everyday lives, yet common devices from electron microscopes to computer transistors rely on it.

    “One limitation you might think of is how fast can I make a transistor work – the ultimate limit will be partly about how quickly quantum particles can tunnel,” says Sang.

    “For a classical computer, it implies a limit as to how quickly you can switch a transistor.”

    As we explore the realms, and limits, of these strange quantum mechanical processes, there may be a speed boost for personal computers, too.

    Griffith University Australian Attosecond Science Facility laser

    Griffith University a breakthrough ‘speed test’ in quantum tunnelling

    The researchers have demonstrated that the electron spends no measurable time “under the potential” as it tunnels through the barrier, but noted that these events “are only as ‘instantaneous’ as the electron wave-function collapse that orthodox interpretations of quantum mechanics” predicts.

    This, Sang adds, offers a tantalising possibility of future zeptosecond lasers – which would operate for a period of time a thousand times shorter than an attosecond – “obtaining information on the dynamics of the wave-function collapse itself”. Such a measurement would explore that most fundamental difference of the quantum to the classical world, where common sense expectations break down in the face of wave-functions describing particles.

    See the full article here .

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    Please help promote STEM in your local schools.

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    Griffith U Campus

    In 1971, Griffith was created to be a new kind of university—one that offered new degrees in progressive fields such as Asian studies and environmental science. At the time, these study areas were revolutionary—today, they’re more important than ever.

    Since then, we’ve grown into a comprehensive, research-intensive university, ranking in the top 5% of universities worldwide. Our teaching and research spans five campuses in South East Queensland and all disciplines, while our network of more than 120,000 graduates extends around the world.

    Griffith continues the progressive traditions of its namesake, Sir Samuel Walker Griffith, who was twice the Premier of Queensland, the first Chief Justice of the High Court of Australia, and the principal author of the Australian Constitution.

     
  • richardmitnick 11:29 am on February 28, 2019 Permalink | Reply
    Tags: "Dark matter detection may involve a pinch of salt", Cosmos Magazine, ,   

    From Stockholm University via COSMOS Magazine: “Dark matter detection may involve a pinch of salt” 

    Stockholm University

    1

    via

    Cosmos Magazine bloc

    COSMOS Magazine

    28 February 2019
    Alan Duffy

    1
    Billion-year-old salt crystals, physicists suggest, could contain conclusive evidence of the existence of dark matter. Allison Achauer/Getty Images.

    Tiny pieces of billion-year-old salt could reveal the existence of dark matter, researchers claim.

    Dark matter is thought to comprise as much as 85% of the universe, but to date billions of dollars spent on high-tech facilities designed to verify its existence have failed to produce unambiguous results.

    Now, a team of physicists headed by Andrzej Drukier from Stockholm University in Sweden suggest a radically different approach.

    Dark matter is thought to be made of subatomic entities known as Weakly Interacting Massive Particles, or, delightfully, WIMPs.

    Current experiments designed to detect them rely on installing huge “target masses”, comprising, for example, 100 tonnes of noble gas, in remote and shielded environments, such as a cave or mine shaft. The targets are then monitored using detectors sensitive enough to pick up the recoil of a nucleus when a WIMP smacks into it.

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington

    LBNL LZ project at SURF, Lead, SD, USA

    The targets are large in order to maximise the chances of a nucleus-WIMP collision – an event that particle physicists agree happens only very rarely because dark matter and visible, or baryonic, matter don’t often interact. They also have to be shielded because many other subatomic phenomena, such as radioactive decay and the impact of cosmic rays, are so much more common by comparison that dark matter is drowned out by the noise.

    Drukier and colleagues advocate a very, very different approach. In a paper published in the journal Physical Review D, they suggest looking closely at 100-milligram mineral crystals in order to find scars from past collisions.

    “We propose to examine ancient minerals for traces of WIMP-nucleus interactions recorded over timescales as large as [one billion years],” they write.

    The logic is compelling. A 100-tonne mass of noble gas monitored for 10 years might record a given number of dark matter collisions. A mineral speck buried in appropriate circumstances for a billion years may well have recorded more.

    To ensure that dark matter interactions aren’t overwritten by natural radioactive decay or even particles from space, Drukier and colleagues propose using salt crystals that formed deep underwater, called marine evaporites.

    “Such minerals have significantly lower concentrations of radioactive contaminants … than typical minerals found in the Earth’s crust,” they say.

    Dark matter is therefore the only source of these interactions, the physicists say, that can leave scars – nanometre-scale marks – on the crystals that can be detected by state-of-the-art technology.

    “Recoiling nuclei leave damage tracks in certain classes of minerals, so-called solid state track detectors,” they write.

    They propose two methods to identify these scars, depending on the size of dark matter particles – a matter which itself is a matter of considerable debate [Journal of Cosmology and Astroparticle Physics].

    Drukier and colleagues say that the damage left by dark matter particles with a mass equivalent to 10 protons or less could be detected using a technique called helium-ion beam microscopy.

    The scars inflicted by larger dark matter candidate particles, with a mass greater than 10 protons, could be detected by using another approach, known as Small-Angle X-ray scattering.

    The idea that ancient minerals could be a path to verifiable dark matter detection is not new. It was first proposed [Physical Review Letters] by another group of physicists in 1995, using a mineral known as muscovite mica.

    That experiment, however, was limited by the measuring technologies then available – a matter readily admitted by the researchers.

    “We argue that a background may not appear until we have pushed our current limits down by several orders of magnitude,” they concluded.

    More than 20 years later, things have changed.

    Drukier’s team call their proposed set-ups “paleo-detectors”. They concede that, as yet, the idea remains largely theoretical, but propose a next step using minerals obtained from close to the surface and subjecting them to approximated WIMP interactions to demonstrate the feasibility of the approach.

    Indeed, they add that their experiments may in time reveal far more about the universe than just the verification of dark matter.

    “The sensitivity and exposure time also makes paleo-detector interesting for a host of applications beyond WIMP dark matter searches,” they write.

    “Examples include studying the time-variability of the fluxes of cosmic rays, or of neutrinos from the Sun or supernovae. Another example would be the study of proton decay facilitated by the large exposure.”

    See the full article here .


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  • richardmitnick 11:21 am on February 19, 2019 Permalink | Reply
    Tags: 24 radio telescopes from the Low Frequency Array (LOFAR), , , , , , Cosmos Magazine, University of Helsinki   

    From University of Helsinki via COSMOS: “Observations reveal new ‘shape’ for coronal mass ejections” 

    From University of Helsinki

    via

    Cosmos Magazine bloc

    COSMOS Magazine

    19 February 2019
    Phil Dooley

    Radiation signatures produced by giant solar storms more complex than previously thought.

    1
    An artist’s impression of a coronal mass ejection. LV4260/Getty Images

    Astronomers using one of the most sensitive arrays of radio telescopes in the world have caught a huge storm erupting on the sun and observed material flung from it at more than 3000 kilometres a second, a massive shockwave and phenomena known as herringbones.

    In the journal Nature Astronomy, Diana Morosan from the University of Helsinki in Finland and her colleagues report detailed observations of the huge storm, a magnetic eruption known as a coronal mass ejection (CME).

    Unlike the herringbones a biologist might find while dissecting, well, a herring, the team found a data-based version while dissecting the radio waves emitted during the violent event.

    The shape of the fish skeleton emerged when they plotted the frequencies of radio waves as the CME evolved. The spine is a band of emission at a constant frequency, while the vertical offshoot “bones” on either side were sudden short bursts of radiation at a much wider range of frequencies.

    Herringbones have been found in the sun’s radio-wave entrails before, but this is the first time that such a sensitive array of radio telescopes has recorded them. The detailed data enabled Morosan and colleagues for the first time to pin down the origin of the radiation bursts.

    To their surprise, the bones were being created in three different locations, on the sides of the CME.

    “I was very excited when I first saw the results, I didn’t know what to make of them,” Morosan says.

    As the CME erupted, the astronomers were already monitoring the sun, using 24 radio telescopes from the Low Frequency Array (LOFAR) distributed around an area of about 320 hectares near the village of Exloo in The Netherlands.

    ASTRON LOFAR Radio Antenna Bank, Netherlands

    SKA LOFAR core (“superterp”) near Exloo, Netherlands

    “We had seen this really complicated active region – really big ugly sunspots, that had already produced three X-class flares, so we thought we should point LOFAR at it and see if it produces any other eruptions,” explains Morosan.

    A last minute request to the LOFAR director was rewarded with an eight-hour slot on the following Sunday, during which the active region erupted again, emitting X-rays so intense that it was classified as an X-class flare, the most extreme category.

    Flares are caused by turbulence in the plasma that makes up the sun. Plasma is gas that is so hot that the electrons begin to be stripped from the atoms, forming a mixture of charged particles. As it swirls around in the sun the charged particles create magnetic fields. When the turbulence rises the magnetic field lines can get contorted and unstable, a little like a tightly coiled and tangled spring.

    Sometimes the tangled magnetic field suddenly rearranges itself in a violent event called magnetic reconnection, a bit like a coiled spring breaking and thus releasing a lot of trapped energy. It is this energy that powers the flare and propels the plasma out into space to form the CME.

    “The CME is still connected to the solar atmosphere via the magnetic field, so it looks like a giant bubble expanding out,” Morosan says.

    The extreme energy in the CME – the second largest during the sun’s most recent 11-year cycle – accelerated matter away from the sun’s surface to over 3000 kilometres per second, or 1% of the speed of light.

    Because it was so fast the CME formed a shockwave as it travelled through the heliosphere – the atmosphere around the sun. Similar to the sonic boom created by a supersonic aircraft, the shockwave accelerated electrons to extreme speeds and caused them to emit radio waves that Morosan and her colleagues recorded.

    The exact frequency of the radio waves emitted by the electrons depends on the density of their environment. Close to the sun the photosphere density is higher, which creates higher frequency radio waves. The further the electrons are from the sun the lower the frequency of the radio emission.

    So the shape of the herringbones as a plot of frequencies shows where the accelerated electrons are in the sun’s atmosphere.

    The spine represents a constant frequency emission originating from electrons trapped in the shockwave. These escape in bursts from the shock and get funneled along the magnetic field lines on the surface of the CME bubble.

    Some bursts of electrons are funneled back towards the sun. These are the herringbone offshoots to higher frequency, while the ones that get funneled the other way, out into space, create offshoots to lower frequency.

    The sensitivity of the array of radio telescopes allowed the team to clearly identify three sources of herringbone radiation, all of them on the flanks of the CME, not at the front of it, as had been proposed.

    However, the success of the observation was cut short because the timeslot on the LOFAR array came to its end, while the CME was still in full swing.

    “We don’t know what happened after the flare peaked,” Morosan notes. “So we were lucky, and unlucky!”

    See the full article here .

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    U Helsinki main building

    University of Helsinki, Viikki campus focusing on biological sciences

    The University of Helsinki (Finnish: Helsingin yliopisto, Swedish: Helsingfors universitet, Latin: Universitas Helsingiensis, abbreviated UH) is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku (in Swedish Åbo) in 1640 as the Royal Academy of Åbo, at that time part of the Swedish Empire. It is the oldest and largest university in Finland with the widest range of disciplines available. Around 36,500 students are currently enrolled in the degree programs of the university spread across 11 faculties and 11 research institutes.

    As of 1 August 2005, the university complies with the harmonized structure of the Europe-wide Bologna Process and offers Bachelor, Master, Licenciate, and Doctoral degrees. Admission to degree programmes is usually determined by entrance examinations, in the case of bachelor’s degrees, and by prior degree results, in the case of master and postgraduate degrees. Entrance is particularly selective (circa 15% of the yearly applicants are admitted). It has been ranked a top 100 university in the world according to the 2016 ARWU, QS and THE rankings.

    The university is bilingual, with teaching by law provided both in Finnish and Swedish. Since Swedish, albeit an official language of Finland, is a minority language, Finnish is by far the dominating language at the university. Teaching in English is extensive throughout the university at Master, Licentiate, and Doctoral levels, making it a de facto third language of instruction.

    Remaining true to its traditionally strong Humboldtian ethos, the University of Helsinki places heavy emphasis on high-quality teaching and research of a top international standard. It is a member of various prominent international university networks, such as Europaeum, UNICA, the Utrecht Network, and is a founding member of the League of European Research Universities.

     
  • richardmitnick 10:32 am on December 4, 2018 Permalink | Reply
    Tags: , , , , Cosmos Magazine, , First stars may have been in massive dark matter halos, Institute for Advanced Study in Princeton New Jersey US, New observations challenge universe model   

    From COSMOS Magazine: “New observations challenge universe model” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    04 December 2018
    Lauren Fuge

    First stars may have been in massive dark matter halos.

    1
    The cosmic microwave background, captured by NASA’s Wilkinson Microwave Anistropy Probe. NASA

    Observations of the very first stars to form might change accepted models of the dawn of the universe.

    A team of astronomers led by Alexander Kaurov of the Institute for Advanced Study in New Jersey, US, says these observations may indicate that the majority of the first stellar generation were located in rare and massive dark matter halos.

    First, though, a quick cosmology refresher.

    Current models tell us that for almost 400,000 years after the Big Bang, the universe was so hot that atoms couldn’t form yet. All that existed was a searing soup of plasma, with photons trapped within it like a fog. But when the universe finally cooled enough for protons and electrons to combine into hydrogen atoms, those photons escaped.

    Today, this jailbreak radiation is known as the cosmic microwave background (CMB). It’s like the universe’s baby photo, and by studying it and the tiny fluctuations within it, we can learn about the system’s infancy and how stars and galaxies began to form.

    The first generation of stars appear so faint and distant that they’re difficult to detect directly. However, astronomers theorised that these stars emitted ultraviolet radiation that heated up the gas around them, which in turn absorbed some of CMB – at radio wavelengths of 21 centimetres, to be specific.

    In March 2018, the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) detected this signal as a small distortion in the CMB, like a fingerprint of the first stars.

    EDGES telescope in a radio quiet zone at the Murchison Radio-astronomy Observatory in Western Australia.

    But upon analysis, the EDGES team realised that the signal’s shape was much deeper than predicted, with sharper boundaries.

    Any number of studies have since attempted to explain the unexpected depth, using new physics or astrophysics. Now, Kaurov’s team at the US Institute for Advanced Study has tackled the signal’s sharp boundaries.

    In a study published in The Astrophysical Journal Letters, he and co-authors argue that this feature indicates that as the first stars lit up, ultraviolet photons flooded the universe much more quickly than expected. The team’s computer simulations showed that this suddenness would occur naturally if the first stars were concentrated in the most massive and rarest dark matter halos – rather than distributed evenly throughout the universe as previously thought.

    These halos, weighing over a billion times more than our Sun, exploded in number in the universe’s infancy and could have easily produced the huge influx of ultraviolet photons necessary to explain the EDGES signal.

    If this scenario is correct, then these rare halos might be bright enough to be observed by the James Webb Space Telescope, which will launch in 2021.

    Time, thus, in more ways than one, will tell.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

     
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