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News Article | May 17, 2017
Site: www.cemag.us

Engineers have invented tiny structures inspired by butterfly wings that open the door to new solar cell technologies and other applications requiring precise manipulation of light. The inspiration comes from the blue Morpho Didius butterfly, which has wings with tiny cone-shaped nanostructures that scatter light to create a striking blue iridescence, and could lead to other innovations such as stealth and architectural applications. Lead researcher Dr. Niraj Lal from the Australian National University Research School of Engineering says the team made similar structures at the nanoscale and applied the same principles in the butterfly wing phenomenon to finely control the direction of light in experiments. "There's a whole bunch of potential new applications using our light-control technique, including next-generation solar cell, architectural and stealth technologies," says Lal. He said scientists can greatly improve the efficiency of solar cells with effective light management. "Techniques to finely control the scattering, reflection and absorption of different colors of light are being used in the next generation of very high-efficiency solar panels," he says. "Being able to make light go exactly where you want it to go has proven to be tricky up until now." Lal says the aim was to absorb all of the blue, green and ultraviolet colors of sunlight in the perovskite layer of a solar cell, and all of the red, orange and yellow light in the silicon layer — known as a tandem solar cell with double-decker layers. Researchers at the ANU surpassed silicon efficiency records with such a cell last month. He says the technique could one day be used to make opaque objects transparent to certain colors, and vice versa, as part of new stealth applications. "We were surprised by how well our tiny cone-shaped structures worked to direct different colors of light where we wanted them to go," Lal says. He says the technique could also be used in architecture to control how much light and heat passed through windows. "Using our approach, a window could be designed to be transparent to some colors non-see through and matt textured for others — so there are very cool potential applications in architecture," Lal says. The technique was very scalable and did not require expensive technology, he says. "These intricate nanostructures grow and assemble themselves — it's not by precise control with a tiny laser or electrons," Lal says. The research paper is published in ACS Photonics, with co-authors Kevin Le, Andrew Thomson, Maureen Brauers, Tom White, and Kylie Catchpole.


News Article | May 25, 2017
Site: www.sciencedaily.com

A team of international astrophysicists led by ANU has shown how most of the antimatter in the Milky Way forms. Antimatter is material composed of the antiparticle partners of ordinary matter -- when antimatter meets with matter, they quickly annihilate each other to form a burst of energy in the form of gamma-rays. Scientists have known since the early 1970s that the inner parts of the Milky Way galaxy are a strong source of gamma-rays, indicating the existence of antimatter, but there had been no settled view on where the antimatter came from. ANU researcher Dr Roland Crocker said the team had shown that the cause was a series of weak supernova explosions over millions of years, each created by the convergence of two white dwarfs which are ultra-compact remnants of stars no larger than two suns. "Our research provides new insight into a part of the Milky Way where we find some of the oldest stars in our galaxy," said Dr Crocker from the ANU Research School of Astronomy and Astrophysics. Dr Crocker said the team had ruled out the supermassive black hole at the centre of the Milky Way and the still-mysterious dark matter as being the sources of the antimatter. He said the antimatter came from a system where two white dwarfs form a binary system and collide with each other. The smaller of the binary stars loses mass to the larger star and ends its life as a helium white dwarf, while the larger star ends as a carbon-oxygen white dwarf. "The binary system is granted one final moment of extreme drama: as the white dwarfs orbit each other, the system loses energy to gravitational waves causing them to spiral closer and closer to each other," Dr Crocker said. He said once they became too close the carbon-oxygen white dwarf ripped apart the companion star whose helium quickly formed a dense shell covering the bigger star, quickly leading to a thermonuclear supernova that was the source of the antimatter.


Online volunteers, including a woman from Belgium and a Scottish man, have helped astronomers at The Australian National University (ANU) find a star that exploded 970 million years ago, predating the dinosaurs' time on Earth. ANU has invited everyone with an interest in astronomy to join the University's search for exploding stars called supernovae, which scientists can use to measure the Universe and acceleration of its growth. Co-lead researcher Dr Brad Tucker said his team was able to confirm a previously unknown object was a real exploding star in just a day, thanks to the efficiency and dedication of volunteer supernovae hunters - more than 700 of them. "The supernova is about 970 million light years away, meaning that it exploded before the dinosaurs were even on the Earth," said Dr Tucker from the ANU Research School of Astronomy and Astrophysics (RSAA). "This is the exact type of supernova we're looking for - type Ia supernova - to measure properties of and distances across the Universe." Among the amateur co-discoverers are Alan Craggs from Aberdeenshire in Scotland and Elisabeth Baeten from Belgium. Seven potential supernovae have been reported to the Transient Name Server. "We are tracking 18 other possible exploding stars," Dr Tucker said. Co-lead researcher Dr Anais Möller said the Ia supernova discovered through the ANU project had already been named. "Supernovae have boring names - it's called SN2017dxh," said Dr Möller from RSAA. "We are recognising volunteers by listing the first three people to find a previously unknown supernova in the discovery when we report it to the International Astronomical Union. "In the first 24 hours we had over 30,000 classifications. We've almost reached 40,000 classifications, with more than 1,300 images classified, since the launch of our project." Astrophysicists use supernovae, which are explosions as bright as 100 million billion billion billion lightning bolts, as light sources to measure how the Universe is growing and better understand dark energy, the cause of the Universe's acceleration. Scientists can measure the distance of a supernova from Earth by calculating how much the light from the exploding star fades. The ANU project allows citizen scientists to use a web portal on Zooniverse.org to search images taken by the SkyMapper 1.3-metre telescope at the ANU Siding Spring Observatory for the SkyMapper Transient Survey. Citizen volunteers scan the SkyMapper images online to look for differences and mark up those differences for the researchers to follow up. SkyMapper is the only telescope that is doing a comprehensive survey of the southern sky looking for supernovae and other interesting transient events at these distances. Watch a video interview with Dr Brad Tucker about the project: youtu.be/NzSG9Ax_e_s People can to participate in the ANU citizen science project at http://www. to join the search for exploding stars.


News Article | May 24, 2017
Site: news.yahoo.com

A star exploded before the time of the dinosaurs, and average people just helped space scientists find it. The stellar explosion called a supernova is 970 million light years away, so we are just seeing it now as it was 970 million years ago — well before dinosaurs dominated Earth. Australian National University scientists have been searching for supernovas and asked the public for help. Hundreds signed up, and, the university said, two online volunteers from Europe recently helped them spot one galaxy’s supernova. After the Belgian woman and Scottish man alerted the team, the scientists aimed a telescope at it to confirm what the object was in just a day’s time. Read: Is This Bright Spot a Supernova or a Black Hole? “This is the exact type of supernova we're looking for … to measure properties of and distances across the universe,” one of the lead researchers, Brad Tucker, said in the ANU statement. Supernovas can potentially help us understand our universe because of how much light they produce. “These explosions are insanely bright,” Tucker explained in a video (below). “So if you can imagine a lightning bolt, imagine a powerful lightning bolt, and then imagine a hundred million billion billion billion of them. That is one star when it blows up.” Those star explosions are relatively rare on the scale of a single human life on Earth, as opposed to a universe that is billions of years old. As famous astrophysicist Neil deGrasse Tyson has pointed out, when describing a supernova explosion as his second favorite way to die in space (his favorite is a black hole), a supernova might happen once per century in each galaxy. It’s the biggest kind of space explosion there is, and it happens when a star accumulates too much mass, either because it is so old or, in binary star systems, where two stars orbit the same point, because it has gobbled up matter from its companion. When scientists look at these exploding stars, the intense light coming off them is “a candle to measure the universe as a whole,” Tucker explained. Measuring how the light source fades over a distance — by looking at how much light is cast upon other objects, for example — tells you how far that distance is. From those measurements, scientists can determine “how the universe is growing and what it’s doing.” Read: How a Black Hole vs. a Supernova Murders You in Space But part of the problem in finding a supernova is manpower. The team needs a pair of eyes checking telescope images to know what to follow up. With the ANU program that leverages amateur astronomers and space enthusiasts, there are many more eyes doing that check work. Once an object is flagged, the scientists can enlist a telescope to better observe it and find out if it truly is a supernova. So far, the project has identified dozens of possible supernovas. “In the first 24 hours we had over 30,000 classifications,” another lead researcher, Anais Möller, said. “We’ve almost reached 40,000 classifications, with more than 1,300 images classified, since the launch of our project.”


Astronomy amateurs have helped Australian scientists find a star that exploded around 970 million years ago – long before the dinosaurs even roamed the Earth. Such exploding stars are known as supernovae. Although they burn only for a short amount of time, they can tell astronomers a lot about the universe. For instance, one type of supernova has allowed them to determine that the universe is expanding at an ever increasing rate. Supernovae are explosions as bright as 100 million billion billion billion lightning bolts, and scientists now use them as light source to measure this growth of the universe. These stars have also been shown to play a key role in the distribution of the elements throughout the universe. When the star explodes, it shoots elements and debris into space and go on to form new stars, planets and everything else in the universe. The newly identified supernova has been named SN2017dxh. Its discovery was made possible thanks to an innovative strategy adopted by the scientists from The Australian National University (ANU). They invited members of the public to join their search for supernovae, asking them them to log on a dedicated web portal and to examine images taken by the SkyMapper 1.3-metre telescope at the ANU Siding Spring Observatory for the SkyMapper Transient Survey. The 700 volunteers who responded to the scientists' call scanned the SkyMapper images online, comparing pictures from the same area of the sky taken at different points in time. They marked up any differences for the researchers to follow up. In just a day, the team was able to confirm that a previously unknown object was a real exploding star. "The supernova is about 970 million light years away, meaning that it exploded before the dinosaurs were even on the Earth," said Dr Tucker from the ANU Research School of Astronomy and Astrophysics (RSAA). "This is the exact type of supernova we're looking for - type Ia supernova - to measure properties of and distances across the Universe." He added that they were currently tracking 18 other possible similar exploding stars. You may be interested in:


ANU has invited everyone with an interest in astronomy to join the University's search for exploding stars called supernovae, which scientists can use to measure the Universe and acceleration of its growth. Co-lead researcher Dr Brad Tucker said his team was able to confirm a previously unknown object was a real exploding star in just a day, thanks to the efficiency and dedication of volunteer supernovae hunters - more than 700 of them. "The supernova is about 970 million light years away, meaning that it exploded before the dinosaurs were even on the Earth," said Dr Tucker from the ANU Research School of Astronomy and Astrophysics (RSAA). "This is the exact type of supernova we're looking for - type Ia supernova - to measure properties of and distances across the Universe." Among the amateur co-discoverers are Alan Craggs from Aberdeenshire in Scotland and Elisabeth Baeten from Belgium. Seven potential supernovae have been reported to the Transient Name Server. "We are tracking 18 other possible exploding stars," Dr Tucker said. Co-lead researcher Dr Anais Möller said the Ia supernova discovered through the ANU project had already been named. "Supernovae have boring names - it's called SN2017dxh," said Dr Möller from RSAA. "We are recognising volunteers by listing the first three people to find a previously unknown supernova in the discovery when we report it to the International Astronomical Union. "In the first 24 hours we had over 30,000 classifications. We've almost reached 40,000 classifications, with more than 1,300 images classified, since the launch of our project." Astrophysicists use supernovae, which are explosions as bright as 100 million billion billion billion lightning bolts, as light sources to measure how the Universe is growing and better understand dark energy, the cause of the Universe's acceleration. Scientists can measure the distance of a supernova from Earth by calculating how much the light from the exploding star fades. The ANU project allows citizen scientists to use a web portal on Zooniverse.org to search images taken by the SkyMapper 1.3-metre telescope at the ANU Siding Spring Observatory for the SkyMapper Transient Survey. Citizen volunteers scan the SkyMapper images online to look for differences and mark up those differences for the researchers to follow up. SkyMapper is the only telescope that is doing a comprehensive survey of the southern sky looking for supernovae and other interesting transient events at these distances. Watch a video interview with Dr Brad Tucker about the project: People can to participate in the ANU citizen science project at http://www.zooniverse.org/projects/skymap/supernova-sighting to join the search for exploding stars. Explore further: Four unknown objects being investigated in Planet 9 search


Online volunteers, including a woman from Belgium and a Scottish man, have helped astronomers at The Australian National University (ANU) find a star that exploded 970 million years ago, predating the dinosaurs' time on Earth. ANU has invited everyone with an interest in astronomy to join the University's search for exploding stars called supernovae, which scientists can use to measure the Universe and acceleration of its growth. Co-lead researcher Dr Brad Tucker said his team was able to confirm a previously unknown object was a real exploding star in just a day, thanks to the efficiency and dedication of volunteer supernovae hunters -- more than 700 of them. "The supernova is about 970 million light years away, meaning that it exploded before the dinosaurs were even on the Earth," said Dr Tucker from the ANU Research School of Astronomy and Astrophysics (RSAA). "This is the exact type of supernova we're looking for -- type Ia supernova -- to measure properties of and distances across the Universe." Among the amateur co-discoverers are Alan Craggs from Aberdeenshire in Scotland and Elisabeth Baeten from Belgium. Seven potential supernovae have been reported to the Transient Name Server. "We are tracking 18 other possible exploding stars," Dr Tucker said. Co-lead researcher Dr Anais Möller said the Ia supernova discovered through the ANU project had already been named. "Supernovae have boring names -- it's called SN2017dxh," said Dr Möller from RSAA. "We are recognising volunteers by listing the first three people to find a previously unknown supernova in the discovery when we report it to the International Astronomical Union. "In the first 24 hours we had over 30,000 classifications. We've almost reached 40,000 classifications, with more than 1,300 images classified, since the launch of our project." Astrophysicists use supernovae, which are explosions as bright as 100 million billion billion billion lightning bolts, as light sources to measure how the Universe is growing and better understand dark energy, the cause of the Universe's acceleration. Scientists can measure the distance of a supernova from Earth by calculating how much the light from the exploding star fades. The ANU project allows citizen scientists to use a web portal on Zooniverse.org to search images taken by the SkyMapper 1.3-metre telescope at the ANU Siding Spring Observatory for the SkyMapper Transient Survey. Citizen volunteers scan the SkyMapper images online to look for differences and mark up those differences for the researchers to follow up. SkyMapper is the only telescope that is doing a comprehensive survey of the southern sky looking for supernovae and other interesting transient events at these distances.


News Article | May 12, 2017
Site: www.eurekalert.org

Scientists have discovered a way to solve a problem that has baffled humans for so long it is mentioned in the Bible: achieving the most efficient packing of objects such as grains and pharmaceutical drugs. Lead researcher Dr Mohammad Saadatfar from The Australian National University (ANU) said the knowledge could be vital for building skyscrapers on sand, understanding how grains were stored in silos, or how drugs were packed and delivered to specific targets in the body. "It's crazy - sand is one of the most common building materials in the world and drugs are often packed in the forms of pills, but we really don't understand how assembly of grains or pills behave," said Dr Saadatfar from the ANU Research School of Physics and Engineering. The international team of physicists and mathematicians used high-resolution CT scans to reveal how spherical particles in a disordered arrangement settle and compact themselves into ordered patterns. "Now we believe that we have uncovered the mechanisms underlying the transition from disordered packing of grains to ordered structures," he said. "Whenever spheres - such as soccer balls, ball bearings or atoms - are packed into a space, the most efficient packing is in a very ordered pattern, known as face-centred cubic. "Sodium and chloride atoms in salt crystals are also arranged and ordered that way." When organised that way, the spheres had a minimum of gaps between them, taking up just over 74 per cent of the space, Dr Saadatfar said. "However, when settling quickly, spheres don't naturally form that arrangement, reaching only 64 per cent at best, an arrangement known as random closed packing," he said. The team had previously shown that the 64 per cent packing is not a random arrangement. In fact, spheres tend to form into tightly-held arrangements of tetrahedra self-organised in rings of five. "For a long time, scientists thought that packing spheres more efficiently was impossible to occur naturally and extremely difficult to observe in the lab," Dr Saadatfar said. "That's because it's hard to move to the perfectly ordered structure. It requires breaking the disordered patterns that developed naturally and that are mechanically robust. "You need to add just the right amount of energy for that - too little energy and the packing remains disordered, too much, the crystal will not form either." Dr Saadatfar said the transition to a tighter packing arrangement was mentioned in the Bible. "Luke 6:38 states 'A good measure, pressed down, shaken together and running over, will be poured into your lap. For with the measure you use, it will be measured to you.' It mentions all the experimental protocols that we used in lab - pressing down, shaking, pouring," Dr Saadatfar said. "I'm not sure the authors of the Bible had nailed the mathematical basis of it." The team used the relatively new field of mathematics known as homology to interpret 3D x-ray microscope images and large-scale computer simulations. Dr Saadatfar said for different particle shapes, the mathematics became much more complex. "When you look at footballs or M&Ms we've got a lot of work to do," Dr Saadatfar said. "I'll be keeping my department supplied with M&Ms for the next few years." The paper, titled 'Pore configuration landscape of granular crystallisation', is published in Nature Communications (DOI:10.1038/NCOMMS15082).


News Article | May 12, 2017
Site: phys.org

Lead researcher Dr Mohammad Saadatfar from The Australian National University (ANU) said the knowledge could be vital for building skyscrapers on sand, understanding how grains were stored in silos, or how drugs were packed and delivered to specific targets in the body. "It's crazy - sand is one of the most common building materials in the world and drugs are often packed in the forms of pills, but we really don't understand how assembly of grains or pills behave," said Dr Saadatfar from the ANU Research School of Physics and Engineering. The international team of physicists and mathematicians used high-resolution CT scans to reveal how spherical particles in a disordered arrangement settle and compact themselves into ordered patterns. "Now we believe that we have uncovered the mechanisms underlying the transition from disordered packing of grains to ordered structures," he said. "Whenever spheres - such as soccer balls, ball bearings or atoms - are packed into a space, the most efficient packing is in a very ordered pattern, known as face-centred cubic. "Sodium and chloride atoms in salt crystals are also arranged and ordered that way." When organised that way, the spheres had a minimum of gaps between them, taking up just over 74 per cent of the space, Dr Saadatfar said. "However, when settling quickly, spheres don't naturally form that arrangement, reaching only 64 per cent at best, an arrangement known as random closed packing," he said. The team had previously shown that the 64 per cent packing is not a random arrangement. In fact, spheres tend to form into tightly-held arrangements of tetrahedra self-organised in rings of five. "For a long time, scientists thought that packing spheres more efficiently was impossible to occur naturally and extremely difficult to observe in the lab," Dr Saadatfar said. "That's because it's hard to move to the perfectly ordered structure. It requires breaking the disordered patterns that developed naturally and that are mechanically robust. "You need to add just the right amount of energy for that - too little energy and the packing remains disordered, too much, the crystal will not form either." Dr Saadatfar said the transition to a tighter packing arrangement was mentioned in the Bible. "Luke 6:38 states 'A good measure, pressed down, shaken together and running over, will be poured into your lap. For with the measure you use, it will be measured to you.' It mentions all the experimental protocols that we used in lab - pressing down, shaking, pouring," Dr Saadatfar said. "I'm not sure the authors of the Bible had nailed the mathematical basis of it." The team used the relatively new field of mathematics known as homology to interpret 3-D x-ray microscope images and large-scale computer simulations. Dr Saadatfar said for different particle shapes, the mathematics became much more complex. "When you look at footballs or M&Ms we've got a lot of work to do," Dr Saadatfar said. "I'll be keeping my department supplied with M&Ms for the next few years." More information: M. Saadatfar et al. Pore configuration landscape of granular crystallization, Nature Communications (2017). DOI: 10.1038/ncomms15082


News Article | May 10, 2017
Site: astrobiology.com

Zircon crystals as old as 4.4 billion years were found in sandstone at Jack Hills of Western Australia. Credit: Stuart Hay, ANU ANU scientists say the early Earth was likely to be barren, mountainless and almost entirely under water with a few small islands, following their analysis of tiny mineral grains as old as 4.4 billion years. Lead researcher Dr Antony Burnham said the team studied zircon mineral grains that were preserved in sandstone rocks in the Jack Hills of Western Australia and which were the oldest fragments of the Earth ever found. "The history of the Earth is like a book with its first chapter ripped out with no surviving rocks from the very early period, but we've used these trace elements of zircon to build a profile of the world at that time," said Dr Burnham from the ANU Research School of Earth Sciences. "Our research indicates there were no mountains and continental collisions during Earth's first 700 million years or more of existence - it was a much more quiet and dull place. "Our findings also showed that there are strong similarities with zircon from the types of rocks that predominated for the following 1.5 billion years, suggesting that it took the Earth a long time to evolve into the planet that we know today." Dr Burnham said the zircon grains that eroded out of the oldest rocks were like skin cells found at a crime scene. "We used the granites of southeast Australia to decipher the link between zircon composition and magma type, and built a picture of what those missing rocks were," he said. The first known form of life emerged some time later, around 3.8 billion years ago. Dr Burnham said the zircon formed by melting older igneous rocks rather than sediments. "Sediment melting is characteristic of major continental collisions, such as the Himalayas, so it appears that such events did not occur during these early stages of Earth's history," he said. Dr Burnham said scientists in the field were able to build on each other's work to gain a better understanding of early Earth. "The samples of zircon from Jack Hills have been collected over the course of several decades by many people, while chemical analyses carried out by an ANU research group 20 years ago have proved invaluable," he said. The study, 'Formation of Hadean granites by melting of igneous crust', is published in Nature Geoscience.

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