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  • richardmitnick 10:05 am on September 7, 2021 Permalink | Reply
    Tags: "Something Mysterious Near The Galactic Center Is Flashing Radio Signals", A newly discovered source of radio signals-called ASKAP J173608.2-321635, , , , MeerKAT/SARAO – SKA South Africa, , , SKA ASKAP Pathfinder Radio Telescope, University of Sydney (AU)   

    From University of Sydney (AU) via Science Alert (US) : “Something Mysterious Near The Galactic Center Is Flashing Radio Signals” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    ScienceAlert

    Science Alert (US)

    7 SEPTEMBER 2021
    MICHELLE STARR

    1
    The galactic center in radio wavelengths. Credit: MeerKAT/SARAO – SKA South Africa.

    As our eyes on the sky grow ever more sensitive, we’re going to find more and more things we’ve never seen before.

    Such is the case for a newly discovered source of radio signals, located not far from the center of the galaxy. It’s called ASKAP J173608.2-321635, and astronomers have been unable to figure out what kind of cosmic object best fits its weird properties.

    Their paper has been accepted for publication in The Astrophysical Journal.

    “We have presented the discovery and characterization of ASKAP J173608.2-321635: a highly-polarized, variable radio source located near the Galactic Center and with no clear multi-wavelength counterpart,” explain a team of astronomers led by Ziteng Wang of the University of Sydney in Australia.

    “ASKAP J173608.2-321635 may represent part of a new class of objects being discovered through radio imaging surveys.”

    ASKAP J173608.2-32163 was discovered using the Australian Square Kilometre Array Pathfinder (ASKAP), one of the most sensitive radio telescopes ever built, designed to peer deep into the radio Universe.

    It’s already proven adept at finding things we have never seen before, such as Odd Radio Circles (we don’t know what those are, yet), undiscovered galaxies, and mysterious fast radio bursts.

    ASKAP J173608.2-32163 might turn out to be a known type of cosmic object, but if it does, it could end up stretch the definition of whatever object that is.

    It’s highly variable, emitting radio waves for weeks at a time, and then disappearing on rapid timescales. The signal is also highly polarized – that is, the orientation of the oscillation of the electromagnetic wave is twisted, both linearly and circularly.

    ASKAP J173608.2-32163 is also quite a tricky beast to spot. The object, whatever it is, had not been seen before the ASKAP detections, made during a pilot survey of the sky to look for transient radio sources. Between April 2019 and August 2020, the signal appeared in the data 13 times.

    Follow-up observations in April and July of 2020 using a different radio telescope, Murriyang in Parkes, Australia, yielded nothing.

    But the MeerKAT radio telescope in South Africa got a hit, in February 2021.

    The Australia Telescope Compact Array (ATCA) also made a detection in April 2021.

    This supports and validates the ASKAP detections, but also suggests that the source is quite elusive – there were no MeerKAT or ATCA detections prior to that date. Nor did the source appear in X-ray and near-infrared observations, nor in archives of radio data collected by multiple instruments that the researchers checked.

    Which leaves a pretty fascinating mystery. The polarization suggests scattering and magnetization, possibly partially due to dust and magnetic fields in the interstellar medium between us and the source, although it’s possible that the source itself is also highly magnetized.

    All up, it’s really hard to figure out what the source might be. There are several types of stars that are known to vary in radio wavelengths, such as stars that flare frequently, or close binaries with active chromospheres, or that eclipse each other. The non-detection in X-ray and near-infrared wavelengths makes this unlikely though.

    Flaring stars usually have X-ray emission that corresponds to the radio emission, and the vast majority of stars have ratios of near-infrared emission that should be detectable.

    Nor is a pulsar likely: a type of neutron star with sweeping beams of radio light, like a cosmic lighthouse. Pulsars have regular periodicity, on a timescale of hours, and ASKAP J173608.2-32163 was detected fading, which is inconsistent with pulsars. Also, there was a three-month span with no detections, which is also inconsistent with pulsars.

    X-ray binaries, gamma-ray bursts, and supernovae were also all ruled out.

    However, the object does share some properties with a type of mysterious signal spotted near the galactic center. These are known as Galactic Center Radio Transients (GCRT), three of which were identified in the 2000s, and more of which are awaiting confirmation.

    These sources are also yet to be explained, but they have several features in common with ASKAP J173608.2-32163.

    If ASKAP J173608.2-32163 is a GCRT, ASKAP’s detection could help us find more such sources, and figure out what they are.

    “Given that ASKAP J173608.2-321635 is typically not detected and can turn off on timescales from several weeks to as quickly as a day, our sparse sampling (12 epochs over 16 months) suggests that there could be other similar sources in these fields,” the researchers write.

    “Increasing the survey cadence and comparing the results of this search to other regions will help us understand how truly unique ASKAP J173608.2-321635 is and whether it is related to the Galactic plane, which should ultimately help us deduce its nature.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. The University of Oxford (UK) didn’t follow suit until 30 years later, and Jesus College at The University of Cambridge (UK) did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

    The University of Sydney (AU) is an Australian public research university in Sydney, Australia. Founded in 1850, it is Australia’s first university and is regarded as one of the world’s leading universities. The university is known as one of Australia’s six sandstone universities. Its campus, spreading across the inner-city suburbs of Camperdown and Darlington, is ranked in the top 10 of the world’s most beautiful universities by the British Daily Telegraph and the American Huffington Post.The university comprises eight academic faculties and university schools, through which it offers bachelor, master and doctoral degrees.

    The QS World University Rankings ranked the university as one of the world’s top 25 universities for academic reputation, and top 5 in the world and first in Australia for graduate employability. It is one of the first universities in the world to admit students solely on academic merit, and opened their doors to women on the same basis as men.

    Five Nobel and two Crafoord laureates have been affiliated with the university as graduates and faculty. The university has educated seven Australian prime ministers, two governors-general of Australia, nine state governors and territory administrators, and 24 justices of the High Court of Australia, including four chief justices. The university has produced 110 Rhodes Scholars and 19 Gates Scholars.

    The University of Sydney (AU) is a member of the Group of Eight, CEMS, the Association of Pacific Rim Universities and the Association of Commonwealth Universities.

     
  • richardmitnick 5:10 pm on August 6, 2021 Permalink | Reply
    Tags: "Solving solar puzzle could help save Earth from planet-wide blackouts", A small-scale solar event in 1989 caused massive blackouts in Canada in what some initially thought might have been a nuclear attack., , In 2012 a solar storm similar in scale to the Carrington Event passed by Earth without impacting missing our orbit around the Sun by just nine days., In the most extreme cases solar geomagnetic storms can shower the Earth with pulses of radiation capable of frying our sophisticated global electronics and communication infrastructure., New solar modelling could help predict space weather., , The 1859 Carrington Event, The Sun’s internal magnetic field is directly responsible for space weather., University of Sydney (AU)   

    From University of Sydney (AU) : “Solving solar puzzle could help save Earth from planet-wide blackouts” 

    U Sidney bloc

    From University of Sydney (AU)

    5 August 2021

    Dr Geoffrey Vasil
    Professor Keith Julien
    Dr Nicholas Featherstone

    New solar modelling could help predict space weather.

    Scientists at the University of Sydney and in the USA have solved a long-standing mystery about the Sun that could help astronomers predict space weather and help us prepare for potentially devastating geomagnetic storms if they were to hit Earth.

    The Sun’s internal magnetic field is directly responsible for space weather – streams of high-energy particles from the Sun that can be triggered by solar flares, sunspots or coronal mass ejections that produce geomagnetic storms. Yet it is unclear how these happen and it has been impossible to predict when these events will occur.

    Now, a new study led by Dr Geoffrey Vasil from the School of Mathematics & Statistics at the University of Sydney could provide a strong theoretical framework to help improve our understanding of the Sun’s internal magnetic dynamo that helps drive near-Earth space weather.

    The Sun is made up of several distinct regions. The convection zone is one of the most important – a 200,000-kilometre-deep ocean of super-hot rolling, turbulent fluid plasma taking up the outer 30 percent of the star’s diameter.

    Existing solar theory suggests the largest swirls and eddies take up the convection zone, imagined as giant circular convection cells.

    However, these cells have never been found, a long-standing problem known as the ‘Convective Conundrum’.

    Dr Vasil said there is a reason for this. Rather than circular cells, the flow breaks up into tall spinning cigar-shaped columns ‘just’ 30,000 kilometres across. This, he said, is caused by a much stronger influence of the Sun’s rotation than previously thought.

    “You can balance a skinny pencil on its point if you spin it fast enough,” said Dr Vasil, an expert in fluid dynamics. “Skinny cells of solar fluid spinning in the convection zone can behave similarly.”

    The findings have been published in the PNAS.

    “We don’t know very much about the inside of the Sun, but it is hugely important if we want to understand solar weather that can directly impact Earth,” Dr Vasil said.

    “Strong rotation is known to completely change the properties of magnetic dynamos, of which the Sun is one.”

    2
    Diagram showing the internal structure of the Sun based on existing theory that assumes circular convection cells near the solar surface. Dr Vasil’s new model suggests thinner, spinning ‘cigar-shaped’ convection cells driving the Sun’s magnetic dynamo. Image: National Aeronautics Space Agency (US).

    Dr Vasil and collaborators Professor Keith Julien of the University of Colorado-Boulder (US) and Dr Nicholas Featherstone at Southwest Research Institute (US) in Boulder, say that this predicted rapid rotation inside the Sun suppresses what otherwise would be larger-scale flows, creating more variegated dynamics for the outer third of the solar depth.

    “By properly accounting for rotation, our new model of the Sun fits observed data and could dramatically improve our understanding of the Sun’s electromagnetic behaviour,” said Dr Vasil, who is the lead author of the study.

    In the most extreme cases solar geomagnetic storms can shower the Earth with pulses of radiation capable of frying our sophisticated global electronics and communication infrastructure.

    A huge geomagnetic storm of this type hit Earth in 1859, known as the Carrington Event, but this was before our global reliance on electronics. The fledgling telegraph system from Melbourne to New York was affected.

    “A similar event today could destroy trillions of dollars’ worth of global infrastructure and take months, if not years, to repair,” Dr Vasil said.


    A solar coronal mass ejection in August 2012
    NASA | Magnificent Eruption in Full HD

    A small-scale event in 1989 caused massive blackouts in Canada in what some initially thought might have been a nuclear attack. In 2012 a solar storm similar in scale to the Carrington Event passed by Earth without impacting missing our orbit around the Sun by just nine days.

    “The next solar max is in the middle of this decade, yet we still don’t know enough about the Sun to predict if these cyclical events will produce a dangerous storm,” Dr Vasil said.

    “While a solar storm hitting Earth is very unlikely, like an earthquake, it will eventually happen and we need to be prepared.”

    Solar storms emerging from within the Sun can take from several hours to days to reach Earth. Dr Vasil said that better knowledge of the internal dynamism of our home star could help planners avoid disaster if they have enough warning to shut down equipment before a blast of energetic particles does the job instead.

    “We cannot explain how sunspots form. Nor can we discern what sunspot groups are most prone to violent rupture. Policymakers need to know how often it might be necessary to endure a days-long emergency shutdown to avoid a severe catastrophe,” he said.

    Dr Vasil and his colleagues’ theoretical model will now need to be tested through observation to further improve the modelling of the Sun’s internal processes. To do this, scientists will use a technique known as helioseismology, to listen inside the beating heart of the star.

    “We hope our findings will inspire further observation and research into the driving forces of the Sun,” he said.

    This could involve the unprecedented launch of polar orbiter observational satellites outside the elliptical plane of the Solar System.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. University of Oxford (UK) didn’t follow suit until 30 years later, and Jesus College at University of Cambridge (UK) did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

    The University of Sydney (AU) is an Australian public research university in Sydney, Australia. Founded in 1850, it is Australia’s first university and is regarded as one of the world’s leading universities. The university is known as one of Australia’s six sandstone universities. Its campus, spreading across the inner-city suburbs of Camperdown and Darlington, is ranked in the top 10 of the world’s most beautiful universities by the British Daily Telegraph and the American Huffington Post. The university comprises eight academic faculties and university schools, through which it offers bachelor, master and doctoral degrees.

    The QS World University Rankings ranked the university as one of the world’s top 25 universities for academic reputation, and top 5 in the world and first in Australia for graduate employability. It is one of the first universities in the world to admit students solely on academic merit, and opened their doors to women on the same basis as men.

    Five Nobel and two Crafoord laureates have been affiliated with the university as graduates and faculty. The university has educated seven Australian prime ministers, two governors-general of Australia, nine state governors and territory administrators, and 24 justices of the High Court of Australia, including four chief justices. The university has produced 110 Rhodes Scholars and 19 Gates Scholars.

    The University of Sydney (AU) is a member of the Group of Eight, CEMS, the Association of Pacific Rim Universities and the Association of Commonwealth Universities.

     
  • richardmitnick 8:54 pm on July 19, 2021 Permalink | Reply
    Tags: "A new world of plasma screens?", Australian researchers have used plasma to make a material that could replace a scarce element used in solar cells; touch screens; and a number of other high-tech manufacturing areas., , The team used a sputtering technique known as "high power impulse magnetron sputtering" (HiPIMS) to create nanometre-sized coats of atoms on surfaces., University of Sydney (AU), Until now the primary substance for the job has been indium tin oxide or ITO-a substance is made of indium; tin; and oxygen – and indium is a scarce resource.   

    From University of Sydney (AU) via COSMOS (AU) : “A new world of plasma screens?” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    Cosmos Magazine bloc

    COSMOS (AU)

    19 July 2021
    Ellen Phiddian

    The fourth state of matter can make cheap, smart, waste-free screen components.

    1
    The plasma used to make the coating. Credit: Dr Behnam Akhavan.

    Australian researchers have used plasma to make a material that could replace a scarce element used in solar cells; touch screens; and a number of other high-tech manufacturing areas.

    In order to work, solar cells and phone and tablet screens need to contain a material that is transparent and can conduct electricity. The material in screen dimmers in cars and smart windows also needs to be electrochromic – that is, able to change colour or transparency depending on an externally applied voltage.

    Until now the primary substance for the job has been indium tin oxide or ITO. As the name suggests, this substance is made of indium; tin; and oxygen – and indium is a scarce resource.

    “A very small amount of it is available,” says Dr Behnam Akhavan, a senior lecturer in engineering at the University of Sydney. Demand is growing for indium because of increasing production of touchscreen devices but, even though only tiny amounts are needed, there are fears supply can’t keep up.

    “It’s also very hard to mine, because we don’t have any indium-specific mines,” says Akhavan. “It comes as a by-product of zinc.”

    Materials scientists have been looking for alternatives to ITO that are transparent, conductive and electrochromic. Two years ago, Akhavan’s team created a material that ticked all of these boxes, consisting of four very thin layers of tungsten and silver on glass. They’ve now been able to refine it down to three layers, simplifying production. And the whole thing has been made using plasma.

    2
    The material: layers of tungsten oxide, silver, and silver/tungsten oxide on glass. Credit: Najafi-Ashtiani et al., 2021, Solar Energy Materials and Solar Cells.

    While plasma’s not common on the Earth’s surface, “it’s the most common state of matter in the universe,” according to Akhavan. “The sun, stars, lightning – they’re all made of plasma.

    “In my research, I create it in the lab to bring in some really fascinating features that other states of matter don’t have, and use it to create new materials.”

    The team used a sputtering technique known as high power impulse magnetron sputtering (HiPIMS) to create nanometre-sized coats of atoms on surfaces.

    “It detaches atoms from the target, and it deposits them on to any material that we want to be coated, such as glass,” says Akhavan.

    In this case, the researchers covered glass with a deposit deposited 30 nanometres of tungsten oxide, followed by 10 nanometres of pure silver and then another 50 nanometres of a “nanocomposite” of tungsten oxide and silver (nanoparticles of silver mixed into tungsten oxide). The result was a clear 90-nanometre-thick coat on the glass (or about a tenth of the size of a small bacterium) that is both conductive and electrochromic.

    Tungsten and silver, while not exactly abundant, are much less rare than indium.

    2
    Dr Behnam Akhavan in the plasma lab. Credit: Dr Behnam Akhavan.

    Akhavan says an immediate use of the technology is as an anti-reflection coating for mirrors. It could also be used in smart windows, which change their transparency to prevent the in-flow of sunlight. Touchscreens could be another potential avenue for the material – although, as these devices usually don’t need to be electrochromic, Akhavan suggests that tungsten could be swapped out for more abundant titanium.

    Another advantage of the technique is that it’s effectively waste-free.

    “It’s a dry process,” says Akhavan. “No solvents or bench chemistry is involved. That makes it very environmentally friendly, because the amount of waste produced is almost zero.”

    The plasma doesn’t deposit materials onto the glass with 100% efficiency, scattering some around the rest of the vessel during the coating process. But these mis-deposited materials remain in an unaffected state and can be re-used with ease, once taken from the vessel.

    “You don’t have to extract them from a solution,” says Akhavan.

    A paper describing the material will be published in Solar Energy Materials and Solar Cells.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

    The University of Sydney (AU) is an Australian public research university in Sydney, Australia. Founded in 1850, it is Australia’s first university and is regarded as one of the world’s leading universities. The university is known as one of Australia’s six sandstone universities. Its campus, spreading across the inner-city suburbs of Camperdown and Darlington, is ranked in the top 10 of the world’s most beautiful universities by the British Daily Telegraph and the American Huffington Post.The university comprises eight academic faculties and university schools, through which it offers bachelor, master and doctoral degrees.

    The QS World University Rankings ranked the university as one of the world’s top 25 universities for academic reputation, and top 5 in the world and first in Australia for graduate employability. It is one of the first universities in the world to admit students solely on academic merit, and opened their doors to women on the same basis as men.

    Five Nobel and two Crafoord laureates have been affiliated with the university as graduates and faculty. The university has educated seven Australian prime ministers, two governors-general of Australia, nine state governors and territory administrators, and 24 justices of the High Court of Australia, including four chief justices. The university has produced 110 Rhodes Scholars and 19 Gates Scholars.

    The University of Sydney (AU) is a member of the Group of Eight, CEMS, the Association of Pacific Rim Universities and the Association of Commonwealth Universities.

     
  • richardmitnick 7:38 am on May 6, 2021 Permalink | Reply
    Tags: "Revealed- coral fights back against crown of thorns starfish", , , , University of Sydney (AU)   

    From University of Sydney (AU) : “Revealed- coral fights back against crown of thorns starfish” 

    U Sidney bloc

    From University of Sydney (AU)

    5 May 2021

    Ivy Shih
    Assistant Media and Public Relations Adviser (Health)
    +61 439 160 475
    ivy.shih@sydney.edu.au

    Coral can fight back against attacking juvenile crown of thorns starfish – using stinging cells to injure and even kill, showing that coral are not as passive as people may think.

    Coral are not completely defenceless against attacking juvenile crown of thorns starfish and can fight back to inflict at times lethal damage, new research has found.

    This occurs during a period of the crown of thorns starfish life cycle, where small juveniles shift from a vegetarian diet of algae to coral prey. But this change in diet makes the juveniles more vulnerable to attack by coral.

    Population outbreaks of adult crown of thorns starfish, alongside coral bleaching is one of the greatest threats to tropical reef habitats.

    Video footage shows when the tube feet (small tube-like projections on the underside of a starfish’s arm used for movement) of juvenile crown of thorns starfish reaches out to touch the coral, the entire arm curls back to avoid the corals’ defensive stinging cells. To protect themselves, coral polyps have stinging cells in their sweeper tentacles and outer tissue called nematocysts, that are also used to capture food.

    1
    A small juvenile crown of thorns starfish (approx. 15 mm) retreating after being stung by coral polyps. Credit: Dione Deaker.

    This encounter damages the arms of juvenile crown of thorn starfish, delaying their growth into adulthood. Researchers also saw a 10 percent fatality rate among the juvenile crown of thorns starfish they studied. However, most juveniles that survived arm damage were able to regenerate partially lost arms.

    The research, published in Marine Ecology Progress Series, was led by Dione Deaker, a PhD student at the University of Sydney, and her supervisor Professor Maria Byrne. The marine scientists say that this is the first study of injury and regeneration in juvenile crown of thorn starfish following damage caused by natural enemies.

    The researchers emphasise the results give a fascinating insight into coral behaviour but the behaviour is not enough to protect it from other threats such as human-caused climate change, overfishing and water pollution.

    Ms Deaker says the period when young crown of thorns starfish shift from a vegetarian diet to eating coral, which is an animal, is a critical one. This is because young crown of thorns starfish who survive have the potential to contribute to population outbreaks that could devastate tropical reefs and coral.

    Previous research [Biology Letters]led by Ms Deaker and Professor Byrne has shown juvenile starfish can survive on algae for more than six years when they were previously thought to change diets at four months old, lying in wait until there is an abundance of coral.

    Caught on tape

    Marine biologists have reported seeing injured juvenile starfish and have suggested that it may be been caused by predators.

    “However, seeing it caused by coral came as a complete surprise,” said Ms Deaker.

    “This shows that the coral use stinging cells as protection to strike back in an attempt to give itself a fighting chance against attacking coral predators.”

    In the study, Ms Deaker and Professor Byrne, along with colleagues at the national Marine Science Centre, Coffs Harbour, monitored the condition, growth and survival of 37 juvenile crown of thorns in isolation away from potential predators and reared them on a diet of coral prey for over 3 months.

    They found coral stings caused injuries that severely reduced the arm length of the starfish by up to 83 percent.

    37.8 percent of juveniles were damaged by coral and four juveniles (10.8 percent) with severe injuries did not recover and died.

    The sting attacks from the coral also delayed the growth of juveniles, extending the time they need to maintain a vegetarian diet.

    The young starfish had a reflex response to being stung when they encountered coral. Their arms recoiled and twisted when their tube feet came into contact with the coral polyps.

    2
    A juvenile crown of thorns starfish with arm regeneration after injury. Credit: Dione Deaker.

    “Sometimes the juveniles never recovered and died, but in most cases injured juveniles recovered and can regenerate their arms in about 4 months,” said Ms Deaker.

    “Despite being prey of crown of thorns starfish, coral can potentially influence the survival of juveniles and the appearance of a population outbreak on a reef by delaying their transition into an adult that can reproduce.”

    Armed with these observations, the study shows that coral are a risky food choice for young crown of thorns starfish.

    Although coral injury was able to slow down the growth of the juvenile starfish, their ability to regenerate shows the resilience of this reef predator as a highly prolific species.

    Professor Byrne said: “The importance of this study in showing the disconnect between size and age of the juveniles reinforces how challenging it is to understand the dynamics of adult population replenishment.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

    The University of Sydney (AU) is an Australian public research university in Sydney, Australia. Founded in 1850, it is Australia’s first university and is regarded as one of the world’s leading universities. The university is known as one of Australia’s six sandstone universities. Its campus, spreading across the inner-city suburbs of Camperdown and Darlington, is ranked in the top 10 of the world’s most beautiful universities by the British Daily Telegraph and the American Huffington Post.The university comprises eight academic faculties and university schools, through which it offers bachelor, master and doctoral degrees.

    The QS World University Rankings ranked the university as one of the world’s top 25 universities for academic reputation, and top 5 in the world and first in Australia for graduate employability. It is one of the first universities in the world to admit students solely on academic merit, and opened their doors to women on the same basis as men.

    Five Nobel and two Crafoord laureates have been affiliated with the university as graduates and faculty. The university has educated seven Australian prime ministers, two governors-general of Australia, nine state governors and territory administrators, and 24 justices of the High Court of Australia, including four chief justices. The university has produced 110 Rhodes Scholars and 19 Gates Scholars.

    The University of Sydney (AU) is a member of the Group of Eight, CEMS, the Association of Pacific Rim Universities and the Association of Commonwealth Universities.

     
  • richardmitnick 10:58 am on April 10, 2021 Permalink | Reply
    Tags: "News-Discovery could help lengthen lifespan of electronic devices", , Tonnes of failed electronic devices go to landfill every year., University of Sydney (AU)   

    From University of Sydney (AU) : “News-Discovery could help lengthen lifespan of electronic devices” 

    U Sidney bloc

    From University of Sydney (AU)

    8 April 2021

    Luisa Low
    Media and PR Adviser (Engineering & IT)
    Phone +61 2 8627 7712
    Mobile +61 438 021 390
    luisa.low@sydney.edu.au

    University of Sydney researchers have made a significant discovery in the field of materials science, for the first time providing a full picture of how fatigue in ferroelectric materials occurs.

    1
    Globally, tens of millions of tonnes of failed electronic devices go to landfill every year. Credit: Pixabay.

    Ferroelectric materials are used in many devices, including memories, capacitors, actuators and sensors. These devices are commonly used in both consumer and industrial instruments, such as computers, medical ultrasound equipment and underwater sonars.

    Over time, ferroelectric materials are subjected to repeated mechanical and electrical loading, leading to a progressive decrease in their functionality, ultimately resulting in failure. This process is referred to as ‘ferroelectric fatigue’.

    It is a main cause of the failure of a range of electronic devices, with discarded electronics a leading contributor to e-waste. Globally, tens of millions of tonnes of failed electronic devices go to landfill every year.

    Using advanced in-situ electron microscopy, the School of Aerospace, Mechanical and Mechatronic Engineering researchers were able to observe ferroelectric fatigue as it occurred. This technique uses an advanced microscope to ‘see’, in real-time, down to the nanoscale and atomic levels.

    The researchers hope this new observation, described in a paper published in Nature Communications, will help better inform the future design of ferroelectric nanodevices.

    “Our discovery is a significant scientific breakthrough as it shows a clear picture of how the ferroelectric degradation process is present at the nanoscale,” said co-author Professor Xiaozhou Liao, also from the University of Sydney Nano Institute.

    Dr Qianwei Huang, the study’s lead researcher, said: “Although it has long been known that ferroelectric fatigue can shorten the lifespan of electronic devices, how it occurs has previously not been well understood, due to a lack of suitable technology to observe it.”

    Co-author Dr Zibin Chen said: “With this, we hope to better inform the engineering of devices with longer lifespans.”

    2
    Electron microscopy images show the degradation in action. Credit: University of Sydney.

    Nobel laureate Herbert Kroemer once famously asserted “The interface is the device”. The observations by the Sydney researchers could therefore spark a new debate on whether interfaces – which are physical boundaries separating different regions in materials – are a viable solution to the unreliability of next-generation devices.

    “Our discovery has indicated that interfaces could actually speed up ferroelectric degradation. Therefore, better understanding of these processes is needed to achieve the best performance of devices,” Dr Chen said.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

    The University of Sydney is an Australian public research university in Sydney, Australia. Founded in 1850, it is Australia’s first university and is regarded as one of the world’s leading universities. The university is known as one of Australia’s six sandstone universities. Its campus, spreading across the inner-city suburbs of Camperdown and Darlington, is ranked in the top 10 of the world’s most beautiful universities by the British Daily Telegraph and the American Huffington Post.The university comprises eight academic faculties and university schools, through which it offers bachelor, master and doctoral degrees.

    The QS World University Rankings ranked the university as one of the world’s top 25 universities for academic reputation, and top 5 in the world and first in Australia for graduate employability. It is one of the first universities in the world to admit students solely on academic merit, and opened their doors to women on the same basis as men.

    Five Nobel and two Crafoord laureates have been affiliated with the university as graduates and faculty. The university has educated seven Australian prime ministers, two governors-general of Australia, nine state governors and territory administrators, and 24 justices of the High Court of Australia, including four chief justices. The university has produced 110 Rhodes Scholars and 19 Gates Scholars.

    The University of Sydney (AU) is a member of the Group of Eight, CEMS, the Association of Pacific Rim Universities and the Association of Commonwealth Universities.

     
  • richardmitnick 12:35 pm on February 5, 2021 Permalink | Reply
    Tags: Astronomers have for the first time used distant galaxies as 'scintillating pins' to locate and identify a piece of the Milky Way's missing matter., , , , , , , This is the first time that multiple 'scintillators' have been detected behind the same cloud of cold gas., University of Sydney (AU)   

    From University of Sydney (AU) via phys.org: “Student astronomer finds missing galactic matter” 

    U Sidney bloc

    From University of Sydney (AU)

    via


    phys.org

    February 5, 2021

    1
    Artist’s impression of a gas cloud from tidal disruption. Credit: University of Sydney.

    Astronomers have for the first time used distant galaxies as ‘scintillating pins’ to locate and identify a piece of the Milky Way’s missing matter.

    For decades, scientists have been puzzled as to why they couldn’t account for all the matter in the universe as predicted by theory. While most of the universe’s mass is thought to be mysterious Dark Matter and Dark Energy, 5 percent is ‘normal matter’ that makes up stars, planets, asteroids, peanut butter and butterflies. This is known as baryonic matter.

    However, direct measurement has only accounted for about half the expected baryonic matter.

    Yuanming Wang, a doctoral candidate in the School of Physics at the University of Sydney, has developed an ingenious method to help track down the missing matter. She has applied her technique to pinpoint a hitherto undetected stream of cold gas in the Milky Way about 10 light years from Earth. The cloud is about a trillion kilometers long and 10 billion kilometers wide but only weighing about the mass of our Moon.

    The results, published in MNRAS, offer a promising way for scientists to track down the Milky Way’s missing matter.

    “We suspect that much of the ‘missing’ baryonic matter is in the form of cold gas clouds either in galaxies or between galaxies,” said Ms Wang, who is pursuing her Ph.D. at the Sydney Institute for Astronomy.

    “This gas is undetectable using conventional methods, as it emits no visible light of its own and is just too cold for detection via radio astronomy,” she said.

    What the astronomers did is look for radio sources in the distant background to see how they ‘shimmered’.

    “We found five twinkling radio sources on a giant line in the sky. Our analysis shows their light must have passed through the same cold clump of gas,” Ms Wang said.

    Just as visible light is distorted as it passes through our atmosphere to give stars their twinkle, when radio waves pass through matter, it also affects their brightness. It was this ‘scintillation’ that Ms Wang and her colleagues detected.

    Dr. Artem Tuntsov, a co-author from Manly Astrophysics, said: “We aren’t quite sure what the strange cloud is, but one possibility is that it could be a hydrogen ‘snow cloud’ disrupted by a nearby star to form a long, thin clump of gas.”

    Hydrogen freezes at about minus 260 degrees and theorists have proposed that some of the universe’s missing baryonic matter could be locked up in these hydrogen ‘snow clouds’. They are almost impossible to detect directly.

    “However, we have now developed a method to identify such clumps of ‘invisible’ cold gas using background galaxies as pins,” Ms Wang said.

    Ms Wang’s supervisor, Professor Tara Murphy, said: “This is a brilliant result for a young astronomer. We hope the methods trailblazed by Yuanming will allow us to detect more missing matter.”

    The data to find the gas cloud was taken using the CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope in Western Australia.

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    Dr. Keith Bannister, Principal Research Engineer at CSIRO, said: “It is ASKAP’s wide field of view, seeing tens of thousands of galaxies in a single observation that allowed us to measure the shape of the gas cloud.”

    Professor Murphy said: “This is the first time that multiple ‘scintillators’ have been detected behind the same cloud of cold gas. In the next few years, we should be able to use similar methods with ASKAP to detect a large number of such gas structures in our galaxy.”

    Ms Wang’s discovery adds to a growing suite of tools for astronomers in their hunt for the universe’s missing baryonic matter. This includes a method published last year by the late Jean-Pierre Macquart from Curtin University who used CSIRO’s ASKAP telescope to estimate a portion of matter in the intergalactic medium using fast radio bursts as ‘cosmic weigh stations’ [Nature].

    See the full article here .
    See also from CSIRO here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 4:31 pm on February 2, 2021 Permalink | Reply
    Tags: "Scientists Achieve 'Transformational' Breakthrough in Scaling Quantum Computers", Gooseberry: Microsoft's new quantum control chip., it approaches the theoretical limit of absolute zero., Physical architecture is constrained because of the extreme conditions qubits need to perform quantum mechanical calculations., , Scientists have developed a new kind of cryogenic computer chip capable of functioning at temperatures so cold, The chip is the most complex electronic system to operate at this temperature., The team expects their system could enable thousands of qubits to be controlled by the cryogenic chip., This cryogenic system called Gooseberry lays the groundwork for what could be a revolution in quantum computing., This is the first time a mixed-signal chip with 100000 transistors has operated at 0.1 kelvin., University of Sydney (AU)   

    From University of Sydney (AU) via Science Alert (AU): “Scientists Achieve ‘Transformational’ Breakthrough in Scaling Quantum Computers” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    ScienceAlert

    Science Alert (AU)

    2 FEBRUARY 2021
    PETER DOCKRILL

    1
    Credit: hh5800/iStock.

    Scientists have developed a new kind of cryogenic computer chip capable of functioning at temperatures so cold, it approaches the theoretical limit of absolute zero.

    This cryogenic system, called Gooseberry, lays the groundwork for what could be a revolution in quantum computing – enabling a new generation of machines to perform calculations with thousands of qubits or more, whereas today’s most advanced devices comprise only dozens.

    “The world’s biggest quantum computers currently operate with just 50 or so qubits,” explains quantum physicist David Reilly from the University of Sydney and Microsoft’s Quantum Laboratory.

    Google 54-qubit Sycamore superconducting processor quantum computer.

    Google quantum computer.

    IBM iconic image of Quantum computer.

    U Chicago Researchers used IBM’s Quantum Experience, an open-access quantum computer, to test fundamental principles of quantum mechanics.

    “This small scale is partly because of limits to the physical architecture that control the qubits.”

    That physical architecture is constrained because of the extreme conditions qubits need to perform quantum mechanical calculations.

    3
    Gooseberry: Microsoft’s new quantum control chip. Credit: Microsoft. (Left) A simplified version of the thermal conductance model of the Gooseberry chip. (Right) Gooseberry chip (red) sits close to the qubit test chip (blue) and resonator chip (purple).

    Unlike the binary bits in traditional computers, which take either a 0 or 1 value, qubits occupy what is known as the quantum superposition – an undefined and unmeasured state that can effectively represent both 0 and 1 at the same time in the context of a larger mathematical operation.

    This esoteric principle of quantum mechanics means quantum computers can theoretically solve vastly complex mathematical problems that classic computers would never be able to answer (or take years trying).

    Like with conventional technology, though, more is always better, and to date, researchers have been limited in how many qubits they’ve been able to successfully deploy into quantum systems.

    One of the reasons for that is qubits need extreme levels of cold to function (in addition to other controlled conditions), and the electrical wiring used in today’s quantum computer systems inevitably output small but sufficient levels of heat that disrupt the thermal requirements.

    Scientists are looking into ways to get around that, but many quantum innovations to date have depended on contriving bulky wiring rigs to keep temperatures stable for increasing qubit counts, but that solution has its own limits.

    “Current machines create a beautiful array of wires to control the signals; they look like an inverted gilded birds’ nest or chandelier,” Reilly says.

    “They’re pretty, but fundamentally impractical. It means we can’t scale the machines up to perform useful calculations. There is a real input–output bottleneck.”

    The solution to that bottleneck could be Gooseberry: a cryogenic control chip that can operate at ‘millikelvin’ temperatures just a tiny fraction of a degree above absolute zero, as described in a new study Nature Electronics [below].

    That extreme thermal capacity means it can sit inside the super-cold refrigerated environment with the qubits, interfacing with them and passing signals from the qubits to a secondary core that sits outside in another extremely cold tank, immersed in liquid helium.

    In doing so, it removes all the excess wiring and the surplus heat they generate, meaning contemporary qubit bottlenecks in quantum computing could soon be a thing of the past.

    “The chip is the most complex electronic system to operate at this temperature,” Reilly explained to Digital Trends.

    “This is the first time a mixed-signal chip with 100,000 transistors has operated at 0.1 kelvin, [the equivalent to] –459.49-degrees Fahrenheit, or –273.05-degrees Celsius.”

    Ultimately, the team expects their system could enable thousands of qubits to be controlled by the cryogenic chip – roughly a 20-fold increase in what’s possible today. In the future, the same sort of approach might enable quantum computers on a whole other level.

    “Why not start thinking about billions of qubits?” Reilly told the Australian Financial Review. “The more qubits we can control, the better.”

    While it may be some time before we see this cryogenic breakthrough put to practical use outside the lab, there’s no doubting we’re looking at a big step forward in quantum computing, experts say.

    “This is going to be transformational in the next few years,” Andrew White, the director of the ARC Centre of Excellence for Engineered Quantum Systems, who wasn’t involved with the study but oversees quantum research in Australia, told ABC News.

    “If everyone [developing quantum computers] isn’t using this chip, they will be using something inspired by it.”

    The findings are reported in Nature Electronics.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 9:28 am on December 23, 2020 Permalink | Reply
    Tags: "Space weather in Proxima’s vicinity dims hopes of habitable worlds", , , , , , , , University of Sydney (AU)   

    From University of Sydney (AU) via EarthSky: “Space weather in Proxima’s vicinity dims hopes of habitable worlds” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    1

    EarthSky

    December 23, 2020
    Paul Scott Anderson

    Astronomers used radio waves to study conditions in the vicinity of Proxima Centauri, the nearest star to our sun. The results suggest Proxima’s 2 known planets are likely bathed in intense radiation from this star, casting doubt on the planets’ potential for life.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    1
    Artist’s concept of huge flares on Proxima Centauri, which unleash ionizing radiation. This radiation could be dangerous for any possible life on planets orbiting close to the star. Image via NASA/ ESA/ G. Bacon (STScI)/ Phys.org.

    This month, even as some astronomers are talking about a possible mystery radio signal from Proxima Centauri – a signal of interest to astronomers who search for intelligent life beyond Earth – other astronomers are talking about space weather in the vicinity of this star, which is the nearest star to our sun. Space weather in Proxima’s vicinity, they are saying, might make life on its planets difficult or even impossible.

    What is space weather?

    When we hear about weather, we might think of Earth – sun, clouds, rain, wind and so on – or we might think about conditions on other planets or moons that have atmospheres. Space weather isn’t about that. It’s a sort of “weather” that originates in stars, including our own sun, and that permeates the space near a star. Space weather consists of ionizing radiation released during flares on the sun, or other stars.

    Space weather. Credit: NASA.

    The radiation can be deadly for any life forms that may exist on distant planets. That’s especially true, astronomers say, for red dwarf stars, which have more frequent flares than our sun. Red dwarf stars can be very volatile. Proxima Centauri is a red dwarf star.

    Astronomers at the University of Sydney in Australia announced the new study on December 10, 2020. These researchers used radio waves to detect and probe the space weather in Proxima’s vicinity. Our sun’s nearest neighbor at only 4.2 light-years away, Proxima is known to have at least two planets orbiting it. One, Proxima Centauri b, is almost the same mass as Earth and the other, Proxima Centauri c, is about seven times more massive. Proxima Centauri b also orbits within its stars’ habitable zone, where temperatures might allow liquid water to exist on planet’s surface. Sounds promising, right? But the new findings about flares on stars like Proxima suggests a grim prospect for life on the planets in this system.

    The researchers published their peer-reviewed findings in The Astronomical Journal on December 9.

    These astronomers worked with CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) telescope in Western Australia and the Zadko Telescope at the University of Western Australia, as well as other instruments. Tara Murphy of the University of Sydney helped lead the study.

    Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Australian Mid West. ASKAP consists of 36 identical parabolic antennas, each 12 metres in diameter, working together as a single instrument with a total collecting area of approximately 4,000 square metres.

    3
    The Zadko telescope is used by staff at the University of Western Australia and scientists in France. Credit: ABC Radio Perth: Emma Wynne.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 10:29 am on December 17, 2020 Permalink | Reply
    Tags: "Secret of Australia’s volcanoes revealed", , , , , They bubbled rather than exploded research shows., University of Sydney (AU),   

    From University of Sydney (AU) via COSMOS (AU): “Secret of Australia’s volcanoes revealed” 

    U Sidney bloc

    From University of Sydney (AU)

    via

    Cosmos Magazine bloc

    COSMOS (AU)

    17 December 2020
    Nick Carne

    They bubbled rather than exploded, research shows.

    2
    Geoscience team on CSIRO’s RV Investigator vessel. Research author Dr Ben Mather from the University of Sydney is third from right. Credit: University of Sydney.

    1
    Mount Kaputar, near Narrabri NSW, was an active volcano 20 million years ago. Credit: Stephen Bittinger / Creative Commons.

    Australia used to be quite a hotbed of volcanic activity. The east coast is littered with the remnants of hundreds of eruptions, the most recent just a few thousand years old.

    Many were one-off events. Some are now notable structures such as Cradle Mountain in Tasmania, the Organ Pipes in Victoria, or the Undara Lava Tubes in Queensland, while others just look like regular hills.

    But volcanic they were, and geoscientists have been at a loss to explain why there was so much action over 80 million years in parts of an otherwise stable continent.

    Now we may be closer to an answer. “Under our east coast we find a special volatile mix of molten rock that bubbles up to the surface through the younger, thinner east coast Australian crust,” says Ben Mather, lead author of a new paper in Science Advances.

    He and colleagues from the University of Sydney (USyd) worked with Monash University and New Zealand’s GNS Science to analyse hundreds of eruptions along the coast from North Queensland to Tasmania and over the Tasman to the largely submerged continent Zealandia.

    They were particularly interested in peaks of activity 20 million and two million years ago.

    “Most of these eruptions are not caused by Australia’s tectonic plate moving over hot plumes in the mantle under the Earth’s crust,” says USyd’s Maria Seton. “Instead, there is a fairly consistent pattern of activity, with a few notable peaks.”

    This became evident because these peaks coincided with an increased volume of seafloor material being pushed under the Australian continental shelf, starting at the Tonga-Kermadec Trench east and north of New Zealand.

    “From there it is being slammed into the transition zone between the crust and the magma at depths of about 400 to 500 kilometres,” says Mather. “This material is then re-emerging as a series of volcanic eruptions along Australia’s east coast, which is thinner and younger than the centre and west of the continent.”

    This process, known as subduction, is not unique to this area, but what sets the east Australia-Zealandia region apart, Mather says, is that the seafloor being moved is highly concentrated with hydrous materials and carbon-rich rocks. “This creates a transition zone right under the east coast of Australia that is enriched with volatile materials.”

    Previous models have suggested volcanoes in Victoria were due to convection eddies in the mantle from being near the trailing edge of the tectonic plate or have relied on the plate passing over hot spots in the mantle.

    “Neither of these gave us the full picture,” Mather says. “But our new approach can explain the volcanic pattern up and down the Australian east coast.”

    It also could also explain intraplate volcanic regions in the Western US, eastern China and around Bermuda, he adds. It can’t, however, predict when the next volcano will emerge.

    See the full article here .


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

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
  • richardmitnick 4:00 pm on December 9, 2020 Permalink | Reply
    Tags: "Space weather discovery puts 'habitable planets' at risk", , , , , , , , University of Sydney (AU)   

    From University of Sydney (AU) via phys.org: “Space weather discovery puts ‘habitable planets’ at risk” 

    U Sidney bloc

    From University of Sydney (AU)

    via


    phys.org

    December 9, 2020

    1
    Artist’s impression of flare from our neighbouring star Proxima Centauri ejecting material onto a nearby planet. Credit: Mark Myers/OzGrav.

    A discovery that links stellar flares with radio-burst signatures will make it easier for astronomers to detect space weather around nearby stars outside the Solar System. Unfortunately, the first weather reports from our nearest neighbour, Proxima Centauri, are not promising for finding life as we know it.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    “Astronomers have recently found [Science Advances] there are two ‘Earth-like’ rocky planets around Proxima Centauri, one within the ‘habitable zone’ [Nature] where any water could be in liquid form,” said Andrew Zic from the University of Sydney.

    Proxima Centauri is just 4.2 light years from Earth.

    “But given Proxima Centauri is a cool, small red-dwarf star, it means this habitable zone is very close to the star; much closer in than Mercury is to our Sun,” he said.

    “What our research shows is that this makes the planets very vulnerable to dangerous ionising radiation that could effectively sterilise the planets.”

    Led by Mr Zic, astronomers have for the first time shown a definitive link between optical flares and radio bursts on a star that is not the Sun. The finding, published today in The Astrophysical Journal, is an important step to using radio signals from distant stars to effectively produce space weather reports.

    “Our own Sun regularly emits hot clouds of ionised particles during what we call ‘coronal mass ejections’. But given the Sun is much hotter than Proxima Centauri and other red-dwarf stars, our ‘habitable zone’ is far from the Sun’s surface, meaning the Earth is a relatively long way from these events,” Mr Zic said.

    “Further, the Earth has a very powerful planetary magnetic field that shields us from these intense blasts of solar plasma.”

    The research was done in collaboration with CSIRO, the University of Western Australia, University of Wisconsin-Milwaukee, University of Colorado and Curtin University. There were contributions from the ARC Centre for Gravitational Waves and University of California Berkeley.

    The study formed part of Mr Zic’s doctoral studies at the Sydney Institute for Astronomy under the supervision of Professor Tara Murphy, deputy head of the School of Physics at the University of Sydney. Mr Zic has now taken a joint position at Macquarie University and CSIRO.

    He said: “M-dwarf radio bursts might happen for different reasons than on the Sun, where they are usually associated with coronal mass ejections. But it’s highly likely that there are similar events associated with the stellar flares and radio bursts we have seen in this study.”

    Coronal mass ejections are hugely energetic expulsions of ionised plasma and radiation leaving the stellar atmosphere.

    “This is probably bad news on the space weather front. It seems likely that the galaxy’s most common stars—red dwarfs—won’t be great places to find life as we know it,” Mr Zic said.

    In the past decade, there has been a renaissance in the discovery of planets orbiting stars outside our Solar System. There are now more than 4000 known exoplanets.

    This has boosted hopes of finding ‘Earth-like’ conditions on exoplanets. Recent research says that about half the Sun-like stars in the Milky Way could be home to such planets. However, Sun-like stars only make up 7 percent of the galaxy’s stellar objects. By contrast, M-type red dwarfs like Proxima Centauri make up about 70 percent of stars in the Milky Way.

    The findings strongly suggest planets around these stars are likely to be showered with stellar flares and plasma ejections.

    Methodology

    The Proxima Centauri observations were taken with the CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) telescope in Western Australia, the Zadko Telescope at the University of Western Australia and a suite of other instruments.

    University of Western Australia scientist Dr. Bruce Gendre, from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), said the research helps understand the dramatic effects of space weather on solar systems beyond our own.

    “Understanding space weather is critical for understanding how our own planet biosphere evolved—but also for what the future is,” Dr. Gendre said.

    Professor Murphy said: “This is an exciting result from ASKAP. The incredible data quality allowed us to view the stellar flare from Proxima Centauri over its full evolution in amazing detail.

    “Most importantly, we can see polarised light, which is a signature of these events. It’s a bit like looking at the star with sunglasses on. Once ASKAP is operating in full survey mode we should be able to observe many more events on nearby stars.”

    This will give us much greater insights to the space weather around nearby stars.

    Other facilities, including NASA’s planet-hunting Transiting Exoplanet Survey Satellite and the Zadko Telescope observed simultaneously with ASKAP providing the crucial link between the radio bursts and powerful optical flares observed.

    Mr Zic said: “The probability that the observed solar flare and received radio signal from our neighbour were not connected is much less than one chance in 128,000.”

    The research shows that planets around Proxima Centauri may suffer strong atmospheric erosion, leaving them exposed to very intense X-rays and ultraviolet radiation.

    But could there be magnetic fields protecting these planets?

    Mr Zic said: “This remains an open question. How many exoplanets have magnetic fields like ours?”

    So far there have been no observations of magnetic fields around exoplanets and finding these could prove tricky. Mr Zic said one potential way to identify distant magnetic fields would be to look for aurorae, like those around Earth and also witnessed on Jupiter.

    “But even if there were magnetic fields, given the stellar proximity of habitable zone planets around M-dwarf stars, this might not be enough to protect them,” Mr Zic said.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Sydney (AU)
    Our founding principle as Australia’s first university, U Sydney was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

    When Charles William Wentworth proposed the idea of Australia’s first university in 1850, he imagined “the opportunity for the child of every class to become great and useful in the destinies of this country”.

    We’ve stayed true to that original value and purpose by promoting inclusion and diversity for the past 160 years.

    It’s the reason that, as early as 1881, we admitted women on an equal footing to male students. Oxford University didn’t follow suit until 30 years later, and Jesus College at Cambridge University did not begin admitting female students until 1974.

    It’s also why, from the very start, talented students of all backgrounds were given the chance to access further education through bursaries and scholarships.

    Today we offer hundreds of scholarships to support and encourage talented students, and a range of grants and bursaries to those who need a financial helping hand.

     
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