Updates from richardmitnick Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 5:01 pm on February 27, 2020 Permalink | Reply
    Tags: "Quantum researchers able to split one photon into three", , Quantum optics,   

    From University of Waterloo: “Quantum researchers able to split one photon into three” 

    U Waterloo bloc

    From University of Waterloo

    February 27, 2020

    Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo report the first occurrence of directly splitting one photon into three.

    The occurrence, the first of its kind, used the spontaneous parametric down-conversion method (SPDC) in quantum optics and created what quantum optics researchers call a non-Gaussian state of light. A non-Gaussian state of light is considered a critical ingredient to gain a quantum advantage.

    “It was understood that there were limits to the type of entanglement generated with the two-photon version, but these results form the basis of an exciting new paradigm of three-photon quantum optics,” said Chris Wilson, a principal investigator at IQC faculty member and a professor of Electrical and Computer Engineering at Waterloo.

    “Given that this research brings us past the known ability to split one photon into two entangled daughter photons, we’re optimistic that we’ve opened up a new area of exploration.”

    1
    Lab of Chris Wilson

    “The two-photon version has been a workhorse for quantum research for over 30 years,” said Wilson. “We think three photons will overcome the limits and will encourage further theoretical research and experimental applications and hopefully the development of optical quantum computing using superconducting units.”

    Wilson used microwave photons to stretch the known limits of SPDC. The experimental implementation used a superconducting parametric resonator. The result clearly showed the strong correlation among three photons generated at different frequencies. Ongoing work aims to show that the photons are entangled.

    “Non-Gaussian states and operations are a critical ingredient for obtaining the quantum advantage,” said Wilson. “They are very difficult to simulate and model classically, which has resulted in a dearth of theoretical work for this application.”

    Science paper:
    “Observation of Three-Photon Spontaneous Parametric Down-Conversion in a Superconducting Parametric Cavity”
    Physical Review X

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Waterloo campus

    In just half a century, the Waterloo, located at the heart of Canada’s technology hub, has become a leading comprehensive university with nearly 36,000 full- and part-time students in undergraduate and graduate programs.

    Consistently ranked Canada’s most innovative university, Waterloo is home to advanced research and teaching in science and engineering, mathematics and computer science, health, environment, arts and social sciences. From quantum computing and nanotechnology to clinical psychology and health sciences research, Waterloo brings ideas and brilliant minds together, inspiring innovations with real impact today and in the future.

    As home to the world’s largest post-secondary co-operative education program, Waterloo embraces its connections to the world and encourages enterprising partnerships in learning, research, and commercialization. With campuses and education centres on four continents, and academic partnerships spanning the globe, Waterloo is shaping the future of the planet.

     
  • richardmitnick 4:29 pm on February 27, 2020 Permalink | Reply
    Tags: , , , Biggest explosion in the history of the Universe, Caltech 2MASS Telescopes a joint project of UMass/Caltech at the Whipple Observatory Mt. Hopkins near Tucson AZ USA Altitude 8550 ft and at the Cerro Tololo Inter-American Observatory altitude 2200 m., , , , , ,   

    From International Centre for Radio Astronomy Research: “Astronomers detect biggest explosion in the history of the Universe” 

    ICRAR Logo
    From International Centre for Radio Astronomy Research

    February 28, 2020
    Professor Melanie Johnson-Hollitt — ICRAR / Curtin University
    Ph: +61 400 951 815
    E: Melanie.Johnston-Hollitt@curtin.edu.au

    Pete Wheeler — Media Contact, ICRAR
    Ph: +61 423 982 018
    E: Pete.Wheeler@icrar.org

    April Kleer — Media Contact, Curtin University
    Ph: +61 9266 3353
    E: April.Kleer@curtin.edu.au

    Scientists studying a distant galaxy cluster have discovered the biggest explosion seen in the Universe since the Big Bang.

    2
    This extremely powerful eruption occurred in the Ophiuchus galaxy cluster, which is located about 390 million light-years from Earth. Galaxy clusters are the largest structures in the Universe held together by gravity, containing thousands of individual galaxies, dark matter, and hot gas. Credits: X-ray: NASA/CXC/Naval Research Lab/Giacintucci, S.; XMM:ESA/XMM; Radio: NCRA/TIFR/GMRTN; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF

    NASA/Chandra X-ray Telescope

    ESA/XMM Newton

    Giant Metrewave Radio Telescope, located near Pune (Narayangaon) in India, operated by the National Centre for Radio Astrophysics, a part of the Tata Institute of Fundamental Research, Mumbai


    Caltech 2MASS Telescopes, a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center (IPAC) at Caltech, at the Whipple Observatory on Mt. Hopkins south of Tucson, AZ, USA Altitude 2,606 m (8,550 ft) and at the Cerro Tololo Inter-American Observatory at an altitude of 2200 meters near La Serena, Chile.

    The blast came from a supermassive black hole at the centre of a galaxy hundreds of millions of light-years away.

    It released five times more energy than the previous record holder.

    Professor Melanie Johnston-Hollitt, from the Curtin University node of the International Centre for Radio Astronomy Research, said the event was extraordinarily energetic.

    “We’ve seen outbursts in the centres of galaxies before but this one is really, really massive,” she said.

    “And we don’t know why it’s so big.

    “But it happened very slowly—like an explosion in slow motion that took place over hundreds of millions of years.”

    The explosion occurred in the Ophiuchus galaxy cluster, about 390 million light-years from Earth.

    It was so powerful it punched a cavity in the cluster plasma—the super-hot gas surrounding the black hole.

    Lead author of the study Dr Simona Giacintucci, from the Naval Research Laboratory in the United States, said the blast was similar to the 1980 eruption of Mount St. Helens, which ripped the top off the mountain.

    “The difference is that you could fit 15 Milky Way galaxies in a row into the crater this eruption punched into the cluster’s hot gas,” she said.

    Professor Johnston-Hollitt said the cavity in the cluster plasma had been seen previously with X-ray telescopes.

    But scientists initially dismissed the idea that it could have been caused by an energetic outburst, because it would have been too big.

    “People were sceptical because the size of outburst,” she said. “But it really is that. The Universe is a weird place.”

    The researchers only realised what they had discovered when they looked at the Ophiuchus galaxy cluster with radio telescopes.

    “The radio data fit inside the X-rays like a hand in a glove,” said co-author Dr Maxim Markevitch, from NASA’s Goddard Space Flight Center.

    “This is the clincher that tells us an eruption of unprecedented size occurred here.”

    The discovery was made using four telescopes; NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton, the Murchison Widefield Array (MWA) in Western Australia and the Giant Metrewave Radio Telescope (GMRT) in India.

    5
    The Murchison Widefield Array (MWA) is a low frequency radio telescope and is the first of four Square Kilometre Array (SKA) precursors to be completed, at the Boolardy station in outback Western Australia. at the Murchison Radio-astronomy Observatory (MRO)

    6
    Tile 107, or “the Outlier” as it is known, is one of 256 tiles of this SKA precursor instruments located 1.5km from the core of the telescope. Lighting the tile and the ancient landscape is the Moon. Photographed by Pete Wheeler, ICRAR.

    Professor Johnston-Hollitt, who is the director of the MWA and an expert in galaxy clusters, likened the finding to discovering the first dinosaur bones.

    “It’s a bit like archaeology,” she said.

    “We’ve been given the tools to dig deeper with low frequency radio telescopes so we should be able to find more outbursts like this now.”

    The finding underscores the importance of studying the Universe at different wavelengths, Professor Johnston-Hollitt said.

    “Going back and doing a multi-wavelength study has really made the difference here,” she said.

    Professor Johnston-Hollitt said the finding is likely to be the first of many.

    “We made this discovery with Phase 1 of the MWA, when the telescope had 2048 antennas pointed towards the sky,” she said.

    “We’re soon going to be gathering observations with 4096 antennas, which should be ten times more sensitive.”

    “I think that’s pretty exciting.”

    The Murchison Widefield Array

    The Murchison Widefield Array (MWA) is a low-frequency radio telescope and is the first of four Square Kilometre Array (SKA) precursors to be completed.


    SKA Square Kilometer Array


    SKA South Africa

    A consortium of partner institutions from seven countries (Australia, USA, India, New Zealand, Canada, Japan, and China) financed the development, construction, commissioning, and operations of the facility. The MWA consortium is led by Curtin University.

    Publication:

    ‘‘Discovery of a giant radio fossil in the Ophiuchus Galaxy Cluster’, published in The Astrophysical Journal on February 28th, 2020.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, <a
    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world's biggest ground-based telescope array.

    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 3:09 pm on February 27, 2020 Permalink | Reply
    Tags: "Magnificent desolation", Concordia research station in Antarctica., Dr. Stijn Thoolen., ESA Concordia Journal   

    From ESA Chronicles From Concordia: “Magnificent desolation” Photo Study 


    European Space Agency
    From ESA Chronicles From Concordia

    ESA Concordia Sunrise Sunrise

    January 2, 2020

    1
    Dr. Stijn Thoolen. ESA Concordia. On our way to Little Dome C I wonder where I am, and what to do with my hands. It reminds me a little of the Matrix’ white room.

    Dr. Stijn Thoolen is the ESA-sponsored medical doctor spending 12 months at Concordia research station in Antarctica. He facilitates a number of experiments on the effects of isolation, light deprivation, and extreme temperatures on the human body and mind. [Find this blog post in the original Dutch below.]

    It is a beautiful summer day. There is even less wind than usual (with constant summer temperatures, almost always a blue sky and few weather changes, we are mainly concerned with wind), so I am not afraid to go outside in my t-shirt today. The sun reflecting off the snow is attacking me from all directions, and I will most probably burn, but I don’t care. It may be my only chance this year (and I imagine that in a few months I will look back on this day just like you must now look back at those days at the beach, or under the green trees, in the warm sun…).

    It is busy in front of the station. To the left, an empty rack is being carried away, to the right boxes are sorted, behind me a human chain is carrying them away into a container, and in front of me the green “Merlot” hoists the heaviest stuff. The chaos has something of a busy market on the village square (but then just a little different). Everyone is helping to organize those few 1000 kilos of food brought in by the overland traverse. It had arrived here yesterday, finally, after a day or ten on the ice. Huge logistics. You could say that all that food has arrived just in time, after that monstrous New Year’s Eve dinner two days ago (never seen so much food, not enjoyable anymore). But now that I see with my own eyes what is being stored in those containers and in the station, I am confident we won’t starve this winter.

    2
    Fuel, food, material, and most importantly: my personal 110 kilos of fun. In the summer period, the traverse travels up and down several times from the coast to Concordia, over the ice cap, to supply the station, and so that we can start our winter with peace of mind.

    3

    The traverse seen by the French Pleiades satellite at an altitude of 700 kilometers. It looks pretty fragile to me. Credits: CNES

    Summer feels like one big party. I have installed myself in the ESA lab by now, as well as within our DC16 crew, who are all still happy to participate in the biomedical research projects (the ESA lab is also a party). Every few days another plane comes in to deliver a new load of guests or equipment, and pick up old ones. Nobody lives here permanently (although some are almost considered part of the furniture after too many summer campaigns). We are all guests, and we are all working towards one common goal: knowledge.

    4
    Greetings from DC16 in summer spirits.. Credits: IPEV / PNRA – S. Guesnier.

    5
    Finally I am installed in the ESA lab. Now that the HOMAIR project also covers for the Dutch, there is no need to worry anymore. Credits: ESA/IPEV/PNRA–S. Thoolen

    There are currently around 70 people here at Concordia, a beautiful collection of the most diverse backgrounds but with that same goal, and all of us equally idiot to think that Antarctica is interesting enough to leave the comfort of home for. Seismologists, carpenters, glaciologists, climatologists, electricians, mechanics, meteorologists, astronomers, plumbers, physicists, physicians, cooks, ICT specialists, a cleaner, and a station leader. It makes for a lively experience and ensures that there is plenty to discover besides writing blog posts.

    6
    Concordia from above. Laboratories and scientific instruments are dotted around the base outside. Credits: CNES

    35 scientific projects are being carried out here this summer. Every day a weather balloon is released at an altitude of approximately 30 kilometers to contribute to our weather forecasts. In a cave 12 meters underground measurements are taken as part of a global earthquake observation network. ESA has installed instruments on the 40-meter high “American Tower” to communicate with satellites that monitor our Earth from outer space. A laser shoots into the air several times a day to better understand the properties of our atmosphere. At the same time, telescopes try to detect new planets that orbit around neighbouring stars lightyears away from us, and somewhere else again radioactive particles are being watched, reaching Concordia from outer space and from our Sun.

    Based on the physical and chemical properties of collected snow, we learn how our climate has changed over the years and what effects that can have on our future. Did you know that you can find traces in this snow of an Indonesian volcanic eruption from almost 60 years ago? And traces of last century’s glory days of nuclear bombing? What happens on the other side of our planet even has its consequences all the way here, at the end of the world.

    And so there is “Little Dome C”, our little brother, 35 kilometers away from us. In the coming years, the aim is to drill about two kilometers into the ice. Perhaps not as deep as the 3270-meter world record achieved by the historic EPICA project here at Dome C in 2004, but the ice cores are expected to be around 1.5 million (!) years old, allowing us to travel back in time twice as far. The ice here is actually a kind of diary of our world, and we can learn what our planet’s climate has looked like before the Pleistocene (something relevant for reasons that I can’t full reproduce). Unbelievable! This place is one big special museum, where we learn about our past, and for our future.

    7
    We even have a McDonalds here. But this one is looking for exoplanets.

    Not only scientifically speaking this place is a party. Concordia is also interesting from a cultural point of view. Apart from a few lost Americans and Swiss, everyone here is French or Italian. As we have already seen I therefore don’t have to worry about the food (as opposed to my weight perhaps), and it is a luxury for improving my languages ​​(and my table soccer skills). It is quite interesting to notice the differences, both in work culture and in leisure activities. With all those different people, every year again group formation unfortunately seems inevitable (it is always easier to stick to your habits), and while the Italians are being Italian and the French are being French, I am kind of stuck in the middle. Perfect. Not only because as a “neutral” person I have the possibility to oversee the whole thing a bit, but especially because it allows me to make a sarcastic joke here and there. There is more than just France or Italy, you know.

    8
    Taadaa, finally the Dutch bed sheet made it to the roof as well.

    Think for example about the “Spacca Ossa”, perhaps the most exclusive nightclub of this world, and the glue of Concordia that makes us all feel like one again. It makes a beautiful scene for the Saturday night, of which I won’t share any photos with you. Our weekend usually starts on Saturday afternoon, and once scienced-out and done with partying, there is much more to enjoy: a home cinema, living room with pool and table soccer tables, an overdose of French comics (never knew that was a thing) and an even larger amount of music and films on the shared multimedia drive (interestingly enough mostly movies of bikini’s and palm trees are playing overtime on TV), a collection of musical instruments, board games, the “Atomic Sausage” (a fantastically crafted-together expired snowmobile that officially maybe doesn’t belong to this list), a gym, a game of rugby or volleyball outside in the snow, and I haven’t even unpacked my personal fun box yet. And then, to head back to the summer spirit and exploit these wonderful sunny days just a bit more, there is the beach. I will never forget the radio conversation that made no sense at all in the middle of all the seriousness: “Houston, for Stijn. We are going to the beach.” “Copy, Stijn”.

    8

    Concordia beach. Ice ocean view, and with a bit of imagination the distant sound of squeaking vehicles is just like a flock of seagulls.

    So it’s a party. Sometimes this place feels like a three-star hotel, with everything you need available. Sometimes it all seems so normal, that I think it may make us spoiled one day. But at that New Year’s Eve dinner two days ago, where everything was in abundance, I spoke with Vivien, our technical chef who is starting his second winterover in Concordia this year. This sense of certainty here is false, he told me, and he is right (is that music still on repeat? You may turn it off now). We are still at Concordia, one the most extreme and isolated places on earth. It is not difficult to imagine how quickly a small mistake can turn into a huge problem. What if the traverse doesn’t show up? What do we do without fresh food, or more important, without fuel? The “Astrolabe”, the ship that travels from Tasmania to coastal station Dumont d’Urville with all those supplies that are eventually brought to Concordia by the traverse, unexpectedly had to return for repairs early this summer. The entire logistics system was turned upside down, the traverse was delayed, and it was just hoping for a little while that we had sufficient reserves. And what if a fire breaks out? Or if someone gets sick? I myself have already hurried back inside a few times with pain in my fingers, and having seen multiple cases of frostbite, some fairly serious cases of altitude sickness (we have 35% less oxygen in the air than at home), and later even a car accident that could have ended much worse, I recognize how unforgiving this place can be. The monthly fire and rescue exercises may not be so bad after all.

    Slowly slowly I am learning about my own limits as well. I try not to be too impulsive (let’s forget about the snow dive at 3 AM last week), and carefully plan and experiment when I go outside. On Sundays I usually go for a run, and bit by bit I manage to keep my fingers and toes sweaty while I struggle increasing distances through the snow at -35 °C. Other gloves, spare goggles, extra batteries for the radio, an extra layer over the legs, but one less on top: it is a nice way to get to know this new, harsh environment.

    When I go running, it is often a few kilometers from the station. Completely wrapped to protect myself, I stare through my half-frozen glasses once again over that endless, motionless ocean of ​​ice. Nothing on the horizon, barren, desolate, colder than anywhere else on Earth and no sign of life whatsoever, except for my own breathing. Typically these are the moments that make me realize it, just like during the trip to Little Dome C, or when collecting snow samples with the glaciologists far from the station. Then I realize where I am, and how vulnerable actually. Then all of it isn’t so obvious anymore indeed.

    But it is these moments especially that make me most enthusiastic about all this. Just having read a book about NASA’s Apollo program, I keep thinking about what Buzz Aldrin had said the moment he first set foot on the moon: “Magnificent desolation”. To me, it describes it perfectly. It feels like a huge privilege to be able to live here for a year in this incredibly bizarre and desolate place. And while I hold on to that feeling, I can only fantasize about how extraordinary the winter must be. That hasn’t even started yet…

    9
    My view from the ESA lab. An almost fake-so-bright horizon on a beautiful summer evening. The halo around the sun is a reflection of tiny ice crystals swirling through the air. A magnificent desolation!

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ESA Concordia Base

    Concordia research station in Antarctica is located on a plateau 3200 m above sea level. A place of extremes, temperatures can drop to –80°C in the winter, with a yearly average temperature of –50°C.

    As Concordia lies at the very southern tip of Earth, the Sun does not rise above the horizon in the winter and does not set in the summer. The crew must live without sunlight for four months of the year.

    The altitude and location mean that the air in Concordia is very thin and holds less oxygen. Venturing outside the base requires wearing layers of clothes and limits the time spent outdoors.

    During the harsh winter no outside help can be flown in or reach the base over land – the crew have to solve any problems on their own.

    In addition, Concordia sits in the largest desert in the world. The air is extremely dry, so the crew suffer from continuously chapped lips and irritated eyes.

    No animals can survive in this region – even bacteria find it hard coping with the extreme temperatures. The nearest human beings are stationed some 600 km away at the Russian Vostok base, making Concordia more remote than the International Space Station.

    In the great open landscape covered in darkness, colours, smells and sounds are almost non-existent, adding to the sense of loneliness.

    The isolation and sensory deprivation can wreak havoc on crewmembers’ biological clock, making it hard to get a good night’s sleep.

    Despite all these hardships, up to 16 people spend around a year at a time living in Concordia in the name of science. Far removed from civilisation, the white world of Antarctica offers researchers the opportunity to collect data and experiment like no other place on Earth.

    The base is so unlike anything found elsewhere in the world that ESA participates in the Italian-French base to research future missions to other planets, using the base as a model for extraterrestrial planets.

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

     
  • richardmitnick 2:28 pm on February 27, 2020 Permalink | Reply
    Tags: "Exploring a Cluster’s Stragglers", , , , ,   

    From AAS NOVA: “Exploring a Cluster’s Stragglers” 

    AASNOVA

    From AAS NOVA

    26 February 2020
    Susanna Kohler

    1
    The field around the old open cluster Collinder 261 (upper center), as seen in a red filter in the Digitized Sky Survey 2. A new study explores unusual stars in this cluster. [ESO/Digitized Sky Survey]

    Though stars within the same cluster all typically form around the same time, they don’t all evolve in the same way. A recent study has carefully explored a population of particularly unusual, straggling stars in the old open cluster Collinder 261.

    2
    This Hubble image of the globular cluster NGC 6362 reveals a number of stars that appear younger and bluer than their companions: so-called blue stragglers. [ESA/Hubble & NASA]

    Why So Blue?

    A stellar cluster is typically born in a burst of star formation that creates member stars from the same source material. After the stars form, the cluster ages over cosmic time, its individual stars evolving according to their masses. Bright, blue, massive stars have short lifespans, evolving quickly off the main sequence; dim, red, low-mass stars live much longer and evolve slowly. This difference causes clusters to become progressively redder as they age.

    For particularly old clusters, we would not expect to see any bright blue stars, as these should have all aged off the main sequence already. And yet, again and again, we find handfuls of these bright blue stars — in the Milky Way’s globular and open clusters, and even in other nearby galaxies. How do these so-called blue stragglers arise?

    3
    Two possible formation channels for blue stragglers: two stars collide (top), or a star gains mass from a binary companion (bottom). [NASA/ESA]

    Oh, to Be Young Again

    Since blue-straggler stars are more massive and brighter than expected for their host cluster, we think they must have gained that mass more recently. There are two proposed rejuvenation scenarios that could create blue stragglers:

    Two stars collide and merge to form one massive star.
    A star gains mass from a close-binary companion.

    By studying populations of blue stragglers and exploring these possibilities, we have the potential opportunity to learn about about cluster dynamics and histories, and about binary systems. But blue stragglers tend to lie near the very crowded centers of galaxies — which makes it difficult to observe individual stars and be certain of their membership in the cluster.

    Led by Maria Rain (University of Padua, Italy), a team of scientists has now met this challenge using the precise stellar measurements of the Gaia mission in conjunction with spectroscopy from an instrument on ESO’s Very Large Telescope in Chile.

    ESA/GAIA satellite

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    The team conducted one of the most detailed studies of a blue straggler population, exploring the open cluster Collinder 261.

    4
    Proper motions for Collinder 261. Black circles are cluster members; blue circles are blue straggler candidates, and orange circles are yellow straggler candidates. [Adapted from Rain et al. 2020]

    Stars of a Different Color

    Aged at 7 to 9.3 billion years, Collinder 261 is one of the oldest open clusters of the Milky Way. Rain and collaborators used Gaia data describing the colors and brightnesses, the proper motions, and the parallaxes of stars in Collinder 261’s field to identify 53 blue straggler candidates and one potential yellow straggler — an evolved blue straggler — in the cluster. The authors then followed up 10 of these stars with spectroscopic measurements, determining that at least five of them are members of close binary systems.

    While these data are not yet enough to draw firm conclusions about the origin of blue stragglers, it should be possible to spectroscopically follow up the remaining candidate stars to learn more. This study provides a particularly detailed exploration of these odd straggling stars, which we can hope to build on in the near future.

    Citation

    “A study of the blue straggler population of the old open cluster Collinder 261,” M. J. Rain et al 2020 AJ 159 59.
    https://iopscience.iop.org/article/10.3847/1538-3881/ab5f0b

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 1:40 pm on February 27, 2020 Permalink | Reply
    Tags: "‘Flash photography’ at the LHC", , , , , , , ,   

    From Symmetry: “‘Flash photography’ at the LHC” 

    Symmetry Mag
    From Symmetry<

    02/27/20
    Sarah Charley

    1
    Photo by Tom Bullock

    An extremely fast new detector inside the CMS detector will allow physicists to get a sharper image of particle collisions.

    Some of the best commercially available high-speed cameras can capture thousands of frames every second. They produce startling videos of water balloons popping and hummingbirds flying in ultra-slow motion.

    But what if you want to capture an image of a process so fast that it looks blurry if the shutter is open for even a billionth of a second? This is the type of challenge scientists on experiments like CMS and ATLAS face as they study particle collisions at CERN’s Large Hadron Collider.

    When the LHC is operating to its full potential, bunches of about 100 billion protons cross each other’s paths every 25 nanoseconds. During each crossing, which lasts about 2 nanoseconds, about 50 protons collide and produce new particles. Figuring out which particle came from which collision can be a daunting task.

    “Usually in ATLAS and CMS, we measure the charge, energy and momentum of a particle, and also try to infer where it was produced,” says Karri DiPetrillo, a postdoctoral fellow working on the CMS experiment at the US Department of Energy’s Fermilab. “We’ve had timing measurements before—on the order of nanoseconds, which is sufficient to assign particles to the correct bunch crossing, but not enough to resolve the individual collisions within the same bunch.”

    Thanks to a new type of detector DiPetrillo and her collaborators are building for the CMS experiment, this is about to change.

    CERN/CMS Detector

    Physicists on the CMS experiment are devising a new detector capable of creating a more accurate timestamp for passing particles. The detector will separate the 2-nanosecond bursts of particles into several consecutive snapshots—a feat a bit like taking 30 billion pictures a second.

    This will help physicists with a mounting challenge at the LHC: collision pileup.

    Picking apart which particle tracks came from which collision is a challenge. A planned upgrade to the intensity of the LHC will increase the number of collisions per bunch crossing by a factor of four—that is from 50 to 200 proton collisions—making that challenge even greater.

    Currently, physicists look at where the collisions occurred along the beamline as a way to identify which particular tracks came from which collision. The new timing detector will add another dimension to that.

    “These time stamps will enable us to determine when in time different collisions occurred, effectively separating individual bunch crossings into multiple ‘frames,’” says DiPetrillo.

    DiPetrillo and fellow US scientists working on the project are supported by DOE’s Office of Science, which is also contributing support for the detector development.

    According to DiPetrillo, being able to separate the collisions based on when they occur will have huge downstream impacts on every aspect of the research. “Disentangling different collisions cleans up our understanding of an event so well that we’ll effectively gain three more years of data at the High-Luminosity LHC. This increase in statistics will give us more precise measurements, and more chances to find new particles we’ve never seen before,” she says.

    The precise time stamps will also help physicists search for heavy, slow moving particles they might have missed in the past.

    “Most particles produced at the LHC travel at close to the speed of light,” DiPetrillo says. “But a very heavy particle would travel slower. If we see a particle arriving much later than expected, our timing detector could flag that for us.”

    The new timing detector inside CMS will consist of a 5-meter-long cylindrical barrel made from 160,000 individual scintillating crystals, each approximately the width and length of a matchstick. This crystal barrel will be capped on its open ends with disks containing delicately layered radiation-hard silicon sensors. The barrel, about 2 meters in diameter, will surround the inner detectors that compose CMS’s tracking system closest to the collision point. DiPetrillo and her colleagues are currently working out how the various sensors and electronics at each end of the barrel will coordinate to give a time stamp within 30 to 50 picoseconds.

    “Normally when a particle passes through a detector, the energy it deposits is converted into an electrical pulse that rises steeply and the falls slowly over the course of a few nanoseconds,” says Joel Butler, the Fermilab scientist coordinating this project. “To register one of these passing particles in under 50 picoseconds, we need a signal that reaches its peaks even faster.”

    Scientists can use the steep rising slopes of these signals to separate the collisions not only in space, but also in time. In the barrel of the detector, a particle passing through the crystals will release a burst of light that will be recorded by specialized electronics. Based on when the intense flash of light arrives at each sensor, physicists will be able to calculate the particle’s exact location and when it passed. Particles will also produce a quick pulse in the endcaps, which are made from a new type of silicon sensor that amplifies the signal. Each silicon sensor is about the size of a domino and can determine the location of a passing particle to within 1.3 millimeters.

    The physicists working on the timing detector plan to have all the components ready and installed inside CMS for the start-up of the High Luminosity LHC in 2027

    “High-precision timing is a new concept in high-energy physics,” says DiPetrillo. “I think it will be the direction we pursue for future detectors and colliders because of its huge physics potential. For me, it’s an incredibly exciting and novel project to be on right now.”

    LHC

    CERN map


    CERN LHC Maximilien Brice and Julien Marius Ordan


    CERN LHC particles

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS

    CERN ATLAS Image Claudia Marcelloni CERN/ATLAS

    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    See the full article here .


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

    Please help promote STEM in your local schools.


    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 12:03 pm on February 27, 2020 Permalink | Reply
    Tags: "From ancient flooding modern insights", , Long-ago record of Bering Strait flooding., Melting ice sheets however may only be the tip of the iceberg (pun intended). A better understanding of Bering Strait flooding may offer fresh insights into the sea-level differences., Study uses long-ago record of Bering Strait flooding to understand how ice sheets responded to climate change.   

    From Harvard Gazette: “From ancient flooding, modern insights” 

    Harvard University

    From Harvard Gazette

    February 26, 2020
    Peter Reuell

    1
    Tamara Pico is the author of a new study which offers more precise dating for the flooding in the Bering Strait that occurred more than 11,000 years ago. Jon Chase/Harvard Staff Photographer.

    Study uses long-ago record of Bering Strait flooding to understand how ice sheets responded to climate change.

    The debate has raged in the world of paleo-climate research for years: When did the land bridge that once connected Asia and North America flood?

    Some researchers say the presence of Pacific species in the Arctic makes the case for some 13,000 years ago. Others, however, point to sediment cores collected from the area as evidence that the flooding occurred later, about 11,500 years ago.

    For Tamara Pico, the issue is not which date is right, but how both — taken together — paint a fuller picture of how sea levels changed in the strait over more than 1,500 years.

    Based on that picture, Pico, Ph.D. ’19, was able to deduce how the ice sheets that covered North America responded to the warming climate, and how their melting might have contributed to climate changes. The study is described in a Feb. 26 paper in Science Advances.

    “If we can understand sea-level change in the region around the ice sheet, we can infer the past history of the ice sheet,” said Pico, who worked in the lab of Jerry Mitrovica, Frank B. Baird Jr. Professor of Science, as a graduate student and is now a National Science Foundation postdoctoral scholar at Caltech. “For me, the central question of this study is about understanding when and how much ice melted [during the deglaciation], because if you don’t know how much ice volume melted, then you don’t know how ice sheets are responding to a changing climate, and that’s really the fundamental question.”

    Melting ice sheets, however, may only be the tip of the iceberg (pun intended). A better understanding of Bering Strait flooding may offer fresh insights into the sea-level differences.

    “Nobody really thinks about using the record of the connection between two oceans as a sea-level record,” Pico said. “But the observations suggest there is a connection early and a connection late. If we trust both of those data sets, then that means there was either a sea level fall or a standstill over that time, and in order to explain that, you need a melting ice sheet nearby.”

    But how can a melting ice sheet lead to sea level falling? The answer, Pico said, is gravity.

    The ice sheets that once covered North America were so massive — some were taller than 9,800 feet, or nearly 2 miles — that they actually perturbed the planet’s gravitational field, attracting ocean water. As they melted and that effect waned, Pico said, local sea levels would drop.

    Elsewhere in the world, though, the story at the time was very different.

    “Globally, we know sea level during this period is rising at something like 10 meters per 1,000 years, so it’s not as if global sea level had stopped rising,” Pico said. “It rises quite a bit over that time, so for local sea level to have stayed the same you need this effect.

    “This time period, from 13,000 years ago to 11,500 years ago, also marks the Younger Dryas cooling period,” Pico said. “Over the last deglaciation … for the most part, temperatures were rising, but based on the Greenland ice-core record, temperatures actually seem to drop over this period, and that’s always been an enigma.”

    Since the 1980s, the prevailing explanation for the cooling has been that a massive influx of cold, fresh water might have led to a change in ocean circulation patterns that weakened the oceans’ ability to act as a global heat sink.

    The work of Pico and colleagues suggests that the melting North American ice sheets could have pumped a steady stream of fresh water into the Arctic — enough to sustain the Younger Dryas for nearly 2,000 years.

    “According to the sea-level record in the Bering Strait, you would need to melt a lot of ice — the equivalent of between 10 and 15 meters of global sea-level rise — and this melting is happening over that entire time,” she said. “So this might be able to explain why the Arctic cooled for that period. Rather than it being a lake that had an outburst flood, it was just the melting ice sheet.”

    Despite the sea-level data from the Bering Strait, that hypothesis hasn’t been universally accepted, Pico said, in part because the study places the melting of the “saddle” — the region where the two North American ice sheets meet — at a time significantly later than many believe it was.

    “Most people assume that happened earlier because, even though sea level was rising quickly around the world, there was a period — called meltwater pulse 1A — when it rose especially fast,” she said. “In that period, sea level rose by 15 to 20 meters in under 300 years. That would require a huge amount of ice melt, and many people have assumed the saddle melted during this time.

    “But that assumed history doesn’t fit the Bering Strait sea-level record,” she continued. “When we use that flooding history as a sea-level record, it’s not consistent with what everyone had assumed before.”

    Ultimately, Pico said, the study offers scientists a fuller picture of a key point in the evolution of the planet from the last glacial maximum to today.

    “That’s what’s been really fun for me about this study,” she said. “It pulls so much together — ocean circulation, the timing of the flood, and also the ice history and how that feeds back into ocean circulation. For paleoclimate, it brings a lot of different parts of the story together.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Harvard University campus
    Harvard University is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 10:59 am on February 27, 2020 Permalink | Reply
    Tags: "A better way to build diamonds", , , With the right amount of pressure and surprisingly little heat a substance found in fossil fuels can transform into pure diamond.   

    From Stanford University and SLAC: “A better way to build diamonds” 

    From SLAC National Accelerator Lab

    and

    Stanford University Name
    Stanford University

    February 25, 2020
    Josie Garthwaite

    With the right amount of pressure and surprisingly little heat, a substance found in fossil fuels can transform into pure diamond.

    It sounds like alchemy: take a clump of white dust, squeeze it in a diamond-studded pressure chamber, then blast it with a laser. Open the chamber and find a new microscopic speck of pure diamond inside.

    A new study from Stanford University and SLAC National Accelerator Laboratory reveals how, with careful tuning of heat and pressure, that recipe can produce diamonds from a type of hydrogen and carbon molecule found in crude oil and natural gas.

    “What’s exciting about this paper is it shows a way of cheating the thermodynamics of what’s typically required for diamond formation,” said Stanford geologist Rodney Ewing, a co-author on the paper, published Feb. 21 in the journal Science Advances.

    1
    A sample of diamond crystals synthesized from triamantane, a type of diamondoid. (Image credit: Sulgiye Park.)

    Scientists have synthesized diamonds from other materials for more than 60 years, but the transformation typically requires inordinate amounts of energy, time or the addition of a catalyst – often a metal – that tends to diminish the quality of the final product. “We wanted to see just a clean system, in which a single substance transforms into pure diamond – without a catalyst,” said the study’s lead author, Sulgiye Park, a postdoctoral research fellow at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth).

    Understanding the mechanisms for this transformation will be important for applications beyond jewelry. Diamond’s physical properties – extreme hardness, optical transparency, chemical stability, high thermal conductivity – make it a valuable material for medicine, industry, quantum computing technologies and biological sensing.

    “If you can make even small amounts of this pure diamond, then you can dope it in controlled ways for specific applications,” said study senior author Yu Lin, a staff scientist in the Stanford Institute for Materials and Energy Sciences (SIMES) at SLAC National Accelerator Laboratory.

    A natural recipe

    3
    Lead study author Sulgiye Park holds a sample of the diamondoid triamantane and a model showing its structure, which features three units or “cages” composed of hydrogen and carbon atoms bonded together. (Image credit: Andrew Brodhead)

    Natural diamonds crystallize from carbon hundreds of miles beneath Earth’s surface, where temperatures reach thousands of degrees Fahrenheit. Most natural diamonds unearthed to date rocketed upward in volcanic eruptions millions of years ago, carrying ancient minerals from Earth’s deep interior with them.

    As a result, diamonds can provide insight into the conditions and materials that exist in the planet’s interior. “Diamonds are vessels for bringing back samples from the deepest parts of the Earth,” said Stanford mineral physicist Wendy Mao, who leads the lab where Park performed most of the study’s experiments.

    To synthesize diamonds, the research team began with three types of powder refined from tankers full of petroleum. “It’s a tiny amount,” said Mao. “We use a needle to pick up a little bit to get it under a microscope for our experiments.”

    At a glance, the odorless, slightly sticky powders resemble rock salt. But a trained eye peering through a powerful microscope can distinguish atoms arranged in the same spatial pattern as the atoms that make up diamond crystal. It’s as if the intricate lattice of diamond had been chopped up into smaller units composed of one, two or three cages.

    Unlike diamond, which is pure carbon, the powders – known as diamondoids – also contain hydrogen. “Starting with these building blocks,” Mao said, “you can make diamond more quickly and easily, and you can also learn about the process in a more complete, thoughtful way than if you just mimic the high pressure and high temperature found in the part of the Earth where diamond forms naturally.”

    Diamondoids under pressure

    3
    After squeezing diamondoid samples and blasting them with a laser, the researchers used a second, cooler laser beam to help characterize the resulting diamond. (Image credit: Andrew Brodhead)

    The researchers loaded the diamondoid samples into a plum-sized pressure chamber called a diamond anvil cell, which presses the powder between two polished diamonds. With just a simple hand turn of a screw, the device can create the kind of pressure you might find at the center of the Earth.

    Next, they heated the samples with a laser, examined the results with a battery of tests, and ran computer models to help explain how the transformation had unfolded. “A fundamental question we tried to answer is whether the structure or number of cages affects how diamondoids transform into diamond,” Lin said. They found that the three-cage diamondoid, called triamantane, can reorganize itself into diamond with surprisingly little energy.

    At 900 Kelvin – which is roughly 1160 degrees Fahrenheit, or the temperature of red-hot lava – and 20 gigapascals, a pressure hundreds of thousands of times greater than Earth’s atmosphere, triamantane’s carbon atoms snap into alignment and its hydrogen scatters or falls away.

    The transformation unfolds in the slimmest fractions of a second. It’s also direct: the atoms do not pass through another form of carbon, such as graphite, on their way to making diamond.

    The minute sample size inside a diamond anvil cell makes this approach impractical for synthesizing much more than the specks of diamond that the Stanford team produced in the lab, Mao said. “But now we know a little bit more about the keys to making pure diamonds.”

    See the full article here .


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

    Stem Education Coalition

    Stanford University campus. No image credit

    Stanford University

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

    Stanford University Seal

    SLAC/LCLS


    SLAC/LCLS II projected view


    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.

    SSRL and LCLS are DOE Office of Science user facilities.

     
  • richardmitnick 10:28 am on February 27, 2020 Permalink | Reply
    Tags: "Ancient meteorite site on Earth could reveal new clues about Mars’ past", Overwhelming evidence exists that Mars had liquid water oceans roughly 4 billion years ago., Suevite rock formed nearly 15 million years ago by the Ries Crater meteorite impact-Similarly impact-generated rocks exist on the rims of ancient crater lakes on Mars,   

    From UC Riverside: “Ancient meteorite site on Earth could reveal new clues about Mars’ past” 

    UC Riverside bloc

    From UC Riverside

    February 26, 2020
    Jules Bernstein

    1
    A sample of suevite rock formed nearly 15 million years ago by the Ries Crater meteorite impact. Similarly impact-generated rocks exist on the rims of ancient crater lakes on Mars. (NASA)

    Scientists have devised new analytical tools to break down the enigmatic history of Mars’ atmosphere — and whether life was once possible there.

    A paper detailing the work was published today in the journal Science Advances. It could help astrobiologists understand the alkalinity, pH and nitrogen content of ancient waters on Mars, and by extension, the carbon dioxide composition of the planet’s ancient atmosphere.

    2
    Jezero Crater, landing site for the upcoming Mars 2020 rover mission. (NASA/JPL/JHUAPL/MSSS/Brown University)

    Mars of today is too cold to have liquid water on its surface, a requirement for hosting life as we know it.

    “The question that drives our interests isn’t whether there’s life on present-day Mars,” said Tim Lyons, UCR distinguished professor of biogeochemistry. “We are driven instead by asking whether there was life on Mars billions of years ago, which seems significantly more likely.”

    However, “Overwhelming evidence exists that Mars had liquid water oceans roughly 4 billion years ago,” Lyons noted.

    The central question astrobiologists ask is how that was possible. The red planet is farther from the sun than Earth is, and billions of years ago the sun generated less heat than it does today.

    “To have made the planet warm enough for liquid surface water, its atmosphere would likely have needed an immense amount of greenhouse gas, carbon dioxide specifically,” explained Chris Tino, a UCR graduate student and co-first-author of the paper along with Eva Stüeken, a lecturer at the University of St. Andrews in Scotland.

    Since sampling Mars’ atmosphere from billions of years ago to learn its carbon dioxide content is impossible, the team concluded that a site on Earth whose geology and chemistry bear similarities to the Martian surface might provide some of the missing pieces. They found it in southern Germany’s Nordlinger Ries crater.

    Formed roughly 15 million years ago after being struck by a meteorite, Ries crater features layers of rocks and minerals better preserved than almost anywhere on Earth.

    The Mars 2020 rover will land in a similarly structured, well-preserved ancient crater. Both places featured liquid water in their distant past, making their chemical compositions comparable.

    According to Tino, it’s unlikely that ancient Mars had enough oxygen to have hosted complex life forms like humans or animals.

    However, some microorganisms could have survived if ancient Martian water had both a neutral pH level and was highly alkaline. Those conditions imply sufficient carbon dioxide in the atmosphere — perhaps thousands of times more than what surrounds Earth today — to warm the planet and make liquid water possible.

    While pH measures the concentration of hydrogen ions in a solution, alkalinity is a measure dependent on several ions and how they interact to stabilize pH.

    “Ries crater rock samples have ratios of nitrogen isotopes that can best be explained by high pH,” Stüeken said. “What’s more, the minerals in the ancient sediments tell us that alkalinity was also very high.”

    However, Martian samples with mineral indicators for high alkalinity and nitrogen isotope data pointing to relatively low pH would demand extremely high levels of carbon dioxide in the past atmosphere.

    The resulting carbon dioxide estimates could help solve the long-standing mystery of how an ancient Mars located so far from a faint early sun could have been warm enough for surface oceans and perhaps life. How such high levels could have been maintained and what might have lived beneath them remain important questions.

    “Before this study, it wasn’t clear that something as straightforward as nitrogen isotopes could be used to estimate the pH of ancient waters on Mars; pH is a key parameter in calculating the carbon dioxide in the atmosphere,” Tino said.

    Funding for this study came from the NASA Astrobiology Institute, where Lyons leads the Alternative Earths team based at UCR.

    Included in the study were Gernot Arp of the Georg-August University of Göttingen and Dietmar Jung of the Bavarian State Office for the Environment.

    When samples from NASA’s Mars 2020 rover mission are brought back to Earth, they could be analyzed for their nitrogen isotope ratios. These data could confirm the team’s suspicion that very high levels of carbon dioxide made liquid water possible and maybe even some forms of microbial life long ago.

    “It could be 10-20 years before samples are brought back to Earth,” Lyons said. “But I am delighted to know that we have perhaps helped to define one of the first questions to ask once these samples are distributed to labs in the U.S. and throughout the world.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Riverside Campus

    The University of California, Riverside is one of 10 universities within the prestigious University of California system, and the only UC located in Inland Southern California.

    Widely recognized as one of the most ethnically diverse research universities in the nation, UCR’s current enrollment is more than 21,000 students, with a goal of 25,000 students by 2020. The campus is in the midst of a tremendous growth spurt with new and remodeled facilities coming on-line on a regular basis.

    We are located approximately 50 miles east of downtown Los Angeles. UCR is also within easy driving distance of dozens of major cultural and recreational sites, as well as desert, mountain and coastal destinations.

     
  • richardmitnick 9:53 am on February 27, 2020 Permalink | Reply
    Tags: , , "Penn Engineers Ensure Quantum Experiments Get Off to the Right Start", Quantum experiments that utilize a defect within diamond to store information have to contend with uncertainty- specifically the number of electrons trapped at that defect when the experiment begins., Penn Engineers have devised a system to reset the starting conditions and test them to see whether they are correct and automatically start the experiment if they are all in a matter of microseconds., Initialization is one of the key fundamental requirements for doing almost any kind of quantum-information processing., (NV)-nitrogen-vacancy center in the diamond., Quantum experiments that utilize a defect within diamond to store information have to contend with uncertainty.   

    From Penn Engineering: “Penn Engineers Ensure Quantum Experiments Get Off to the Right Start” 

    From University of Pennsylvania Engineering

    Feb 17, 2020

    1
    Quantum experiments that utilize a defect within diamond to store information have to contend with uncertainty, specifically, the number of electrons trapped at that defect when the experiment begins. Penn Engineers have now developed an initialization procedure that addresses this problem. (Illustration: Ann Sizemore Blevins)

    2
    Tzu-Yung Huang, Lee Bassett and David Hopper in the Quantum Engineering Laboratory. (Image: Penn Engineering)

    The quantum mechanical properties of electrons are beginning to open the door to a new class of sensors and computers with abilities far beyond what their counterparts based in classical physics can accomplish. Quantum states are notoriously difficult to read or write, however, and to make things worse, uncertainty about those states’ starting conditions can make experiments more laborious or even impossible.

    Now, Penn Engineers have devised a system to reset those starting conditions, test them to see whether they are correct, and automatically start the experiment if they are, all in a matter of microseconds.

    This new “initialization procedure” will save quantum researchers the time and effort of re-running experiments to statistically account for uncertain starting states, and enable new kinds of measurements that require exact starting conditions to be run at all.

    Lee Bassett, assistant professor in the Department of Electrical and Systems Engineering and director of the Quantum Engineering Laboratory, along with lab members David Hopper and Joseph Lauigan, led a recent study demonstrating this new initialization procedure. Lab member Tzu-Yung Huang also contributed to the study.

    It was published in the journal Physical Review Applied.

    “Initialization is one of the key, fundamental requirements for doing almost any kind of quantum-information processing,” Bassett says. “You need to be able to deterministically set your quantum state before you can do anything useful with it, but the dirty little secret is that, in almost all quantum architectures, that initialization is not perfect.”

    “Some of the time,” Hopper says, “we can accept that uncertainty, and by running an experimental protocol many thousands of times, come up with a measurement we’re ultimately confident in. But there are other experiments we’d like to do where this type of averaging over multiple runs won’t work.”

    The particular type of uncertainty the researchers investigated has to do with a commonly used quantum system known as a nitrogen-vacancy (NV) center in diamond. These NV centers are defects that naturally occur within diamond, where the regular lattice of carbon atoms is occasionally disrupted with a nitrogen atom and a vacant spot next to it. The electron clouds of neighboring atoms overlap at this empty space, creating a “trapped molecule” in the diamond that can be probed with a laser, allowing researchers to measure, or alter, the electrons’ quantum property known as “spin.”

    The electrons trapped at an NV center form a “qubit” — the basic unit of quantum information — that can be used to sense local fields, store quantum superposition states, and even perform quantum computations.

    “Electrons are excellent magnetic sensors,” Bassett says, “and they can even detect the tiny magnetic fields associated with carbon nuclei surrounding the defect. Those nuclei can serve as qubits themselves and be controlled using the central electron to build up the entangled quantum states that form the basis of quantum computers. They also couple to photons, which are used to transmit quantum information over long distances. So NV centers really merge the three main areas of quantum science: sensing, communication and computation.”

    As promising as NV centers are, researchers still must contend with an uncertain variable: the number of electrons that are trapped at the NV center when an experiment starts, as electrons can hop in and out of the defect when it is illuminated with a laser. An initialization procedure that guarantees a predictable number of electrons every time would reduce the amount of time it takes to successfully run an experiment, or enable experiments where uncertain starting conditions can’t be statistically corrected for after the fact.

    “The NV center is like a box with a coin inside,” Lauigan says. “If we want to do our experiment only when the coin is on heads, we have to shake the box, check the coin, and repeat until we find that it landed the right way up. That’s the initialization procedure.”

    To execute this initialization, the researchers used a pair of lasers, photon detectors and specialized hardware that could handle the precise timing necessary.

    “We shine a green laser at the NV center, which basically ‘flips the coin’ and mixes up the number of electrons that are trapped in the defect,” Hopper says. “Then we come in with a red laser, and depending on the number of electrons that are there, the defect will either emit a photon or remain dark.”

    “Once we detect the photon that tells us the right number of electrons are in the defect, specialized circuitry automatically starts the experiment,” Huang says. “This all happens in about 500 nanoseconds; there isn’t time to have the signal analyzed by a normal computer, so it all has to happen on these specialized chips called field programmable gate arrays.”

    The researchers leveraged the power of advanced classical electronics to better control a particular quantum sensing system. They showed that, thanks to ideal starting conditions, their device can detect a tiny oscillating magnetic field of only 1.3 nanoteslas in one second of measurements, which is a sensitivity record for room-temperature quantum sensors based on single NV centers.

    The researchers’ initialization procedure may also help hasten progress on new quantum architectures for computation and communication. Diamond is typically composed of two stable isotopes of carbon, carbon-12 and carbon-13. The former is the most common, but every few tenths of a nanometer, there is an atom of the latter. And because carbon-13 has an extra neutron, it exhibits nuclear spin and can be used as a qubit.

    An NV center can be a “handle” for controlling those nuclear-spin qubits in a quantum computer, but in this situation the ability to precisely initialize its state becomes crucial. The errors associated with poor initialization multiply, and it quickly becomes impossible to perform a complex calculation. The type of real-time measurement and control used by the team in this work is a major step towards implementing more sophisticated error-correcting protocols in these quantum devices.

    In the near term, the improved sensing ability will be useful in determining the locations of carbon-13 atoms in the diamond lattice.

    “Finding all of those special carbon atoms is a laborious process, since there are so many atoms and each measurement takes a very long time,” Hopper says. “When we started this project, our goal was to see what was making those measurements take so long and whether there was any way to shorten it.”

    The research was supported by the National Science Foundation under awards ECCS-1553511 and ECCS-1842655.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Penn campus

    Penn Engineering – Galway, Ireland

    Academic life at Penn is unparalleled, with 100 countries and every U.S. state represented in one of the Ivy League’s most diverse student bodies. Consistently ranked among the top 10 universities in the country, Penn enrolls 10,000 undergraduate students and welcomes an additional 10,000 students to our world-renowned graduate and professional schools.

    Penn’s award-winning educators and scholars encourage students to pursue inquiry and discovery, follow their passions, and address the world’s most challenging problems through an interdisciplinary approach.

     
  • richardmitnick 9:05 am on February 27, 2020 Permalink | Reply
    Tags: , , , , , , OZGRAV - ARC Centres of Excellence for Gravitational Wave Discovery   

    From ARC Centres of Excellence for Gravitational Wave Discovery via phys.org: “Future space detector LISA could reveal the secret life and death of stars” 

    arc-centers-of-excellence-bloc

    From ARC Centres of Excellence for Gravitational Wave Discovery

    via


    phys.org

    1
    Artist’s illustration of an ‘isolated neutron star’—one without associated supernova remnants, binary companions or radio pulsations. Credit: Casey Reed – Penn State University

    A team of astrophysicists led by Ph.D. student Mike Lau, from the ARC Centre of Excellence in Gravitational Wave Discovery (OzGrav), recently predicted that gravitational waves of double neutron stars may be detected by the future space satellite LISA. The results were presented at the 14th annual Australian National Institute for Theoretical Astrophysics (ANITA) science workshop 2020. These measurements may help decipher the life and death of stars.

    Lau, first author of the paper, compares his team to astro-paleontologists: “Like learning about a dinosaur from its fossil, we piece together the life of a binary star from their double neutron star fossils.”

    A neutron star is the remaining ‘corpse’ of a huge star after the supernova explosion that occurs at the end of its life. A double neutron star, a system of two neutron stars orbiting each other, produces periodic disturbances in the surrounding space-time, much like ripples spreading on a pond surface. These ‘ripples’ are called gravitational waves, and made headlines when the LIGO/Virgo Collaboration detected them for the first time in 2015. These gravitational waves formed when a pair of black holes spiraled too close together and merged.

    However, scientists still haven’t found a way to measure the gravitational waves given off when two neutron stars or black holes are still far apart in their orbit. These weaker waves hold valuable information about the lives of stars and could reveal the existence of entirely new object populations in our Galaxy.

    The recent study [below] shows that the Laser Interferometer Space Antenna (LISA) could potentially detect these gravitational waves from double neutron stars.

    ESA/NASA eLISA

    ESA/NASA eLISA space based, the future of gravitational wave research

    LISA is a space-borne gravitational-wave detector that is scheduled for launch in 2034, as part of a mission led by the European Space Agency. It’s made of three satellites linked by laser beams, forming a triangle that will orbit the Sun. Passing gravitational waves will stretch and squeeze the 40 million-kilometer laser arms of this triangle. The highly sensitive detector will pick up the slowly-oscillating waves—these are currently undetectable by LIGO and Virgo.

    MIT /Caltech Advanced aLigo


    VIRGO Gravitational Wave interferometer, near Pisa, Italy

    Using computer simulations to model a population of double neutron stars, the team predicts that in four years of operation, LISA will have measured the gravitational waves emitted by dozens of double neutron stars as they orbit each other. Their results were published in the Monthly Notices of the Royal Astronomical Society.

    A supernova explosion kicks the neutron star it forms and makes the initial circular orbit oval-shaped. Usually, gravitational wave emission rounds off the orbit—that is the case for double neutron stars detected by LIGO and Virgo. But LISA will be able to detect double neutron stars when they’re still far apart, so it may be possible to catch a glimpse of the oval orbit.

    How oval the orbit is, described as the eccentricity of the orbit, can tell astronomers a lot about what the two stars looked like before they became double neutron stars. For example, their separation and how strongly they were ‘kicked’ by the supernova.

    The understanding of binary stars—stars that are born as a pair—is plagued with many uncertainties. Scientists hope that by the 2030s, LISA’s detection of double neutron stars will shed some light on their secret lives.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    About Science X in 100 words
    Science X™ is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.
    Mission 12 reasons for reading daily news on Science X Organization Key editors and writersinclude 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

    OzGrav

    THE ARC CENTRE of excellence FOR GRAVITATIONAL WAVE DISCOVERY
    A new window of discovery.
    A new age of gravitational wave astronomy.
    One hundred years ago, Albert Einstein produced one of the greatest intellectual achievements in physics, the theory of general relativity. In general relativity, spacetime is dynamic. It can be warped into a black hole. Accelerating masses create ripples in spacetime known as gravitational waves (GWs) that carry energy away from the source. Recent advances in detector sensitivity led to the first direct detection of gravitational waves in 2015. This was a landmark achievement in human discovery and heralded the birth of the new field of gravitational wave astronomy. This was followed in 2017 by the first observations of the collision of two neutron-stars. The accompanying explosion was subsequently seen in follow-up observations by telescopes across the globe, and ushered in a new era of multi-messenger astronomy.

    The mission of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) is to capitalise on the historic first detections of gravitational waves to understand the extreme physics of black holes and warped spacetime, and to inspire the next generation of Australian scientists and engineers through this new window on the Universe.

    OzGrav is funded by the Australian Government through the Australian Research Council Centres of Excellence funding scheme, and is a partnership between Swinburne University (host of OzGrav headquarters), the Australian National University, Monash University, University of Adelaide, University of Melbourne, and University of Western Australia, along with other collaborating organisations in Australia and overseas.

    ________________________________________________________

    The objectives for the ARC Centres of Excellence are to to:

    undertake highly innovative and potentially transformational research that aims to achieve international standing in the fields of research envisaged and leads to a significant advancement of capabilities and knowledge
    link existing Australian research strengths and build critical mass with new capacity for interdisciplinary, collaborative approaches to address the most challenging and significant research problems
    develope relationships and build new networks with major national and international centres and research programs to help strengthen research, achieve global competitiveness and gain recognition for Australian research
    build Australia’s human capacity in a range of research areas by attracting and retaining, from within Australia and abroad, researchers of high international standing as well as the most promising research students
    provide high-quality postgraduate and postdoctoral training environments for the next generation of researchers
    offer Australian researchers opportunities to work on large-scale problems over long periods of time
    establish Centres that have an impact on the wider community through interaction with higher education institutes, governments, industry and the private and non-profit sector.

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