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  • richardmitnick 4:51 pm on January 16, 2018 Permalink | Reply
    Tags: , , , Viewpoint: Spin Gyroscope is Ready to Look for New Physics   

    From Physics: “Viewpoint: Spin Gyroscope is Ready to Look for New Physics” 

    Physics LogoAbout Physics

    Physics Logo 2

    Physics

    January 16, 2018
    Derek F. Jackson Kimball, Department of Physics, California State University, East Bay

    An enhanced version of a magnetometer based on atomic spins could be used to search for theoretically predicted exotic fields with ultrahigh sensitivity.

    1
    Romalis and colleagues [3] have greatly enhanced the sensitivity of an atom-based magnetometer, which can be used not only to detect magnetic fields, but also to search for exotic fields predicted by certain theories. Their device is called a comagnetometer because it uses two types of atoms—in this case, helium (orange) and xenon (blue)—to detect a field. The field torques the spins on the atoms, causing them to precess at well-defined frequencies. The Romalis team measures the precession frequencies of the helium and xenon atoms via the precessing atoms’ effect on the spin precession of a third species, rubidium (green), which they detect with a laser.

    Why is gravity so much weaker than the other fundamental forces? What are dark matter and dark energy? And why is there vastly more matter than antimatter in the Universe? Physicists have proposed a wide variety of theories to solve these mysteries. It turns out that a ubiquitous prediction of these theories is the existence of exotic fields that generate tiny torques on the spins of atoms. Numerous experiments are actively searching for such effects [1, 2], though none have been observed so far. Michael Romalis and co-workers from Princeton University, New Jersey, have perfected an atomic spin “gyroscope” that stands to greatly contribute to these searches [3]. The device detects torques on atomic spins with exquisite accuracy, and it will enable new, more sensitive searches for fields predicted by an assortment of theories.

    Atoms are supremely accurate measurement devices. A good example is the atomic clock, which is the primary standard for the unit of time and is the heart of the global positioning system (GPS). In an atomic clock, the frequency of a periodic signal—the number of “ticks” per second of the clock—is referenced to the energy difference between two quantum states. The fact that this energy difference depends solely on the internal interactions among the atom’s electrons and nucleus is why an atomic clock is so accurate. Indeed, as far as we can tell, the clock’s frequency is a constant of nature.

    The “built in” accuracy means that atoms can do more than just keep time: they can also detect external fields with high sensitivity. That’s precisely the idea behind atomic magnetometry [4]—the basis for the technique that Romalis and colleagues use. Atomic magnetometry entails using, for example, laser light to optically detect a shift in the relative energy between various atomic states caused by an external magnetic field. Alternatively, one can understand the principle behind atomic magnetometry by thinking of the field-sensing atom as a gyroscope. Recall that a spinning top on Earth will “wobble,” or precess, because of the torque from gravity. Similarly, the magnetic dipole associated with an atomic spin will precess at a well-defined frequency (the Larmor frequency) if it experiences a torque from a magnetic field. Exotic fields could also exert a torque on the atomic spins, but because the effects are expected to be so small, researchers must eliminate any “prosaic” external perturbations to see them.

    The Princeton team tackles these perturbative effects by enhancing an existing scheme for an atomic spin gyroscope with several ingenious techniques. To start, the researchers use a form of atom magnetometry, known as comagnetometry [5], which makes it easier to disentangle the effects of an exotic field from those caused by other sources, such as a change in the local magnetic field, an accidental rotation of the experiment, or light from the probe laser. In comagnetometry, the same field, magnetic or otherwise, is measured using two different, but overlapping, gases of atoms. In this case, the gases are isotopes of helium and xenon with nonzero spin, and they are contained in a marble-sized glass vapor cell. The ratio between the precession frequencies of the two types of atoms is generally expected to be different, depending on whether the atoms’ precession is caused by exotic fields or any of the sources listed above. This allows the relative contributions of the different sources (any of which could be zero) to be disentangled by varying certain experimental parameters.

    Previous comagnetometry experiments typically measured the helium and xenon precession frequencies using a sensor that was placed outside the vapor cell [6, 7]. Romalis and co-workers instead follow a practice known to offer greater sensitivity, which is to measure these frequencies via their effect on a third species, rubidium, which is added to the cell in gaseous form (Fig. 1). The team then uses a laser to monitor the rubidium atoms’ precession in response to the precession of the helium and xenon magnetic dipoles.

    Although these methods have been used before, the Princeton team achieves a new level of sensitivity by following several steps. First, they reduce the deleterious effects of collisions between rubidium atoms by keeping the rubidium spins aligned with one another, which requires applying a synchronized series of laser-light pulses and magnetic-field pulses. Second, they minimize the perturbation to the helium and xenon spins caused by collisions with the rubidium atoms. To do so, they apply a complicated series of magnetic field pulses to the sample that “averages away” the effects of both the rubidium spins and the pulses themselves. However, this second set of pulses, which optimizes accuracy, is incompatible with the first series of pulses, which optimizes sensitivity. To get the best of both worlds, the team therefore probes the helium and xenon spins under the first pulse sequence, but only before and after the spins have been allowed to precess “in the dark” for a roughly 200 second period. During this time, the researchers block the laser light and apply the second pulse sequence.

    This combination of techniques results in an atomic spin gyroscope with properties that are among the best in the world for such a device: a precession-frequency stability of better than 7 nHz and an absolute accuracy (in the measured precession frequency) at the sub-ppm level [3]. The first number, for example, means that the Princeton team’s atomic spin gyroscope can sense torques so small that, in the absence of other effects, they would cause atomic spins to precess with periods of longer than four years. This opens the possibility of probing subtle exotic-field effects that may have evaded detection in past experiments.

    Startling discoveries are sometimes hiding just beyond the horizon of our measurement accuracy. In this sense, the Princeton group’s atomic spin gyroscope promises to open new vistas in the hunt for exotic physics. Some of the many possibilities include the search for dark matter fields [8], new long-range forces [9], and permanent electric dipole moments, whose hypothetical existence has been tied to the source of the Universe’s matter-antimatter asymmetry [10]. Eventually, the tool is poised to be the most sensitive means of searching for gravitationally induced torques on spins that aren’t expected in our current theory of gravity [11].

    This research is published in Physical Review Letters.

    References

    1. D. DeMille, J. M. Doyle, and A. O. Sushkov, “Probing the Frontiers of Particle Physics with Tabletop-Scale Experiments,” Science 357, 990 (2017).
    2. M. S. Safronova, D. Budker, D. DeMille, D. F. Jackson Kimball, A. Derevianko, and C. W. Clark, “Search for New Physics with Atoms and Molecules,” arXiv:1710.01833.
    3. M. E. Limes, D. Sheng, and M. V. Romalis, “3He−129Xe Comagnetometery Using 87Rb
    Detection and Decoupling,” Phys. Rev. Lett. 120, 033401 (2018).
    4.Optical Magnetometry, edited by D. Budker and D. F. Jackson Kimball (Cambridge University Press, Cambridge, 2013)[Amazon][WorldCat].
    5.S. K. Lamoreaux, J. P. Jacobs, B. R. Heckel, F. J. Raab, and E. N. Fortson, “New Limits on Spatial Anisotropy from Optically-Pumped 201Hg
    and 199Hg” Phys. Rev. Lett. 57, 3125 (1986).
    6.K. Tullney et al., “Constraints on Spin-Dependent Short-Range Interaction Between Nucleons,” Phys. Rev. Lett. 111, 100801 (2013).
    7.A. G. Glenday, C. E. Cramer, D. F. Phillips, and R. L. Walsworth, “Limits on Anomalous Spin-Spin Couplings Between Neutrons,” Phys. Rev. Lett. 101, 261801 (2008).
    8.D. Budker, P. W. Graham, M. Ledbetter, S. Rajendran, and A. O. Sushkov, “Proposal for a Cosmic Axion Spin Precession Experiment (CASPEr),” Phys. Rev. X 4, 021030 (2014).
    9. G. Vasilakis, J. M. Brown, T. W. Kornack, and M. V. Romalis, “Limits on New Long Range Nuclear Spin-Dependent Forces Set with a K
    – 3HemComagnetometer,” Phys. Rev. Lett. 103, 261801 (2009).
    10. B. Graner, Y. Chen, E. G. Lindahl, and B. R. Heckel, “Reduced Limit on the Permanent Electric Dipole Moment of 199Hg
    ,” Phys. Rev. Lett. 116, 161601 (2016).
    11. D. F. Jackson Kimball, J. Dudley, Y. Li, D. Patel, and J. Valdez, “Constraints on Long-Range Spin-Gravity and Monopole-Dipole Couplings of the Proton,” Phys. Rev. D 96, 075004 (2017).

    See the full article here .

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    Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries. Physics provides a much-needed guide to the best in physics, and we welcome your comments (physics@aps.org).

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  • richardmitnick 4:31 pm on January 16, 2018 Permalink | Reply
    Tags: , , , CHIME telescope, , New Canadian telescope will map largest volume of space ever surveyed,   

    From UBC: “New Canadian telescope will map largest volume of space ever surveyed” 

    U British Columbia bloc

    University of British Columbia

    Sep 7, 2017 [Where has this been hiding?]
    Heather Amos

    Radio telescope will help the world’s astronomers, physicists and scientists unravel today’s biggest cosmic mysteries.

    A Canadian effort to build one of the most innovative radio telescopes in the world will open the universe to a new dimension of scientific study. Hon. Kirsty Duncan, minister of science, today installed the final piece of this new radio telescope, which will act as a time machine allowing scientists to create a three-dimensional map of the universe extending deep into space and time.

    The Canadian Hydrogen Intensity Mapping Experiment, known as CHIME, is an extraordinarily powerful new telescope.

    CHIME Canadian Hydrogen Intensity Mapping Experiment A partnership between the University of British Columbia McGill University, at the Dominion Radio Astrophysical Observatory in British Columbia

    The unique “half-pipe” telescope design and advanced computing power will help scientists better understand the three frontiers of modern astronomy: the history of the universe, the nature of distant stars and the detection of gravitational waves.

    By measuring the composition of dark energy, scientists will better understand the shape, structure and fate of the universe. In addition, CHIME will be a key instrument to study gravitational waves, the ripples in space-time that were only recently discovered, confirming the final piece of Einstein’s theory of general relativity.

    CHIME is a collaboration among 50 Canadian scientists from the University of British Columbia, the University of Toronto, McGill University, and the National Research Council of Canada (NRC). The $16-million investment for CHIME was provided by the Canada Foundation for Innovation and the governments of British Columbia, Ontario, and Quebec, with additional funding from the Natural Sciences and Engineering Research Council and the Canadian Institute for Advanced Research. The telescope is located in the mountains of British Columbia’s Okanagan Valley at the NRC’s Dominion Radio Astrophysical Observatory near Penticton.

    Quotes

    “CHIME is an extraordinary example showcasing Canada’s leadership in space science and engineering. The new telescope will be a destination for astronomers from around the world who will work with their Canadian counterparts to answer some of the most profound questions about space. Our government believes in providing scientists with the opportunities and tools they need to pursue the answers to questions that keep them up at night.”

    – Hon. Kirsty Duncan, Minister of Science

    “The National Research Council works hand-in-hand with academia for the advancement of knowledge in Canada. CHIME is a shining example of what outcomes we can achieve, working in collaboration, for today and tomorrow, for Canada and beyond.”

    – Iain Stewart, President of the National Research Council of Canada

    “With the CHIME telescope we will measure the expansion history of the universe and we expect to further our understanding of the mysterious dark energy that drives that expansion ever faster. This is a fundamental part of physics that we don’t understand and it’s a deep mystery. This is about better understanding how the universe began and what lies ahead.”

    – Mark Halpern, University of British Columbia

    “CHIME’s unique design will enable us to tackle one of the most puzzling new areas of astrophysics today – Fast Radio Bursts. The origin of these bizarre extragalactic events is presently a mystery, with only two dozen reported since their discovery a decade ago. CHIME is likely to detect many of these objects every day, providing a massive treasure trove of data that will put Canada at the forefront of this research.”

    – Victoria Kaspi, McGill University

    “CHIME ‘sees’ in a fundamentally different way from other telescopes. A massive supercomputer is used to process incoming radio light and digitally piece together an image of the radio sky. All that computing power also lets us do things that were previously impossible: we can look in many directions at once, run several experiments in parallel, and leverage the power of this new instrument in unprecedented ways.”

    – Keith Vanderlinde, University of Toronto
    Quick facts

    The CHIME telescope incorporates four 100-metre long U-shaped cylinders of metal mesh that resemble snowboard half-pipes. Its overall footprint is the size of five NHL hockey rinks.
    CHIME collects radio waves with wavelengths between 37 and 75 centimetres, similar to the wavelength used by cell phones.
    Most of the signals collected by CHIME come from our Milky Way galaxy, but a tiny fraction of these signals started on their way when the universe was between 6 and 11 billion years old.
    The radio signal from the universe is very weak and extreme sensitivity is needed to detect it. The amount of energy collected by CHIME in one year is equivalent to the amount of energy gained by a paper clip falling off a desk to the floor.
    The data rate passing through CHIME is comparable to all the data in the world’s mobile networks. There is so much data that it cannot all be saved to disk. It must first be processed and compressed by a factor of 100,000.
    Seven quadrillion computer operations occur every second on CHIME. This rate is equivalent to every person on Earth performing one million multiplication problems every second.

    See the full article here .

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    U British Columbia Campus

    The University of British Columbia is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
  • richardmitnick 2:52 pm on January 16, 2018 Permalink | Reply
    Tags: , , , , , , , , The Dark Sector   

    From Symmetry: “Voyage into the dark sector” 

    Symmetry Mag

    Symmetry

    01/16/18
    Sarah Charley

    1
    Artwork by Sandbox Studio, Chicago with Ana Kova

    A hidden world of particles awaits. [We hope!]

    We don’t need extra dimensions or parallel universes to have an alternate reality superimposed right on top of our own. Invisible matter is everywhere.

    For example, take neutrinos generated by the sun, says Jessie Shelton, a theorist at the University of Illinois at Urbana-Champaign who works on dark sector physics. “We are constantly bombarded with neutrinos, but they pass right through us. They share the same space as our atoms but almost never interact.”

    As far as scientists can tell, neutrinos are solitary particles. But what if there is a whole world of particles that interact with one another but not with ordinary atoms? This is the idea behind the dark sector: a theoretical world of matter existing alongside our own but invisible to the detectors we use to study the particles we know.

    “Dark sectors are, by their very definition, built out of particles that don’t interact strongly with the Standard Model,” Shelton says.

    The Standard Model is a physicist’s field guide to the 17 particles and forces that make up all visible matter.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    Standard Model of Particle Physics from Symmetry Magazine

    It explains how atoms can form and why the sun shines. But it cannot explain gravity, the cosmic imbalance of matter and antimatter, or the disparate strengths of nature’s four forces.

    CERN ALPHA Antimatter Factory

    On its own, an invisible world of dark sector particles cannot solve all these problems. But it certainly helps.

    2
    Artwork by Sandbox Studio, Chicago with Ana Kova

    The main selling point for the dark sector is that the theories comprehensively confront the problem of dark matter. Dark matter is a term physicists coined to explain bizarre gravitational effects they observe in the cosmos. Distant starlight appears to bend around invisible objects as it traverses the cosmos, and galaxies spin as if they had five times more mass than their visible matter can explain. Even the ancient light preserved in cosmic microwave background seems to suggest that there is an invisible scaffolding on which galaxies are formed.

    Some theories suggest that dark matter is simple cosmic debris that adds mass—but little else—to the complexity of our cosmos. But after decades of searching, physicists have yet to find dark matter in a laboratory experiment. Maybe the reason scientists haven’t been able to detect it is that they’ve been underestimating it.

    “There is no particular reason to expect that whatever is going on in the dark sector has to be as simple as our most minimal models,” Shelton says. “After all, we know that our visible world has a lot of rich physics: Photons, electrons, protons, nuclei and neutrinos are all critically important for understanding the cosmology of how we got here. The dark sector could be a busy place as well.”

    According to Shelton, dark matter could be the only surviving particle out of a similarly complicated set of dark particles.

    “It could even be something like the proton, a bound state of particles interacting via a very strong dark force. Or it could even be something like a hydrogen atom, a bound state of particles interacting via a weaker dark force,” she says.

    Even if terrestrial experiments cannot see these stable dark matter particles directly, they might be sensitive to other kinds of dark particles, such as dark photons or short-lived dark particles that interact strongly with the Higgs boson.

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    “The Higgs is one of the easiest ways for the Standard Model particles to talk to the dark sector,” Shelton says.

    As far as scientists know, the Higgs boson is not picky. It may very well interact will all sorts of massive particles, including those invisible to ordinary atoms. If the Higgs boson interacts with massive dark sector particles, scientists should find that its properties deviate slightly from the Standard Model’s predictions. Scientists at the Large Hadron Collider are precisely measuring the properties of the Higgs boson to search for unexpected quirks that could open a gateway to new physics.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    At the same time, scientists are also using the LHC to search for dark sector particles directly. One theory is that at extremely high temperatures, dark matter and ordinary matter are not so different and can transform into one another through a dark force. In the hot and dense early universe, this would have been quite common.

    “But as the universe expanded and cooled, this interaction froze out, leaving some relic dark matter behind,” Shelton says.

    The energetic particle collisions generated by the LHC imitate the conditions that existed in the early universe and could unlock dark sector particles. If scientists are lucky, they might even catch dark sector particles metamorphosing into ordinary matter, an event that could materialize in the experimental data as particle tracks that suddenly appear from no apparent source.

    But there are also several feasible scenarios in which any interactions between the dark sector and our Standard Model particles are so tiny that they are out of reach of modern experiments, according to Shelton.

    “These ‘nightmare’ scenarios are completely logical possibilities, and in this case, we will have to think very carefully about astrophysical and cosmological ways to look for the footprints of dark particle physics,” she says.

    Even if the dark sector is inaccessible to particle detectors, dark matter will always be visible through the gravitational fingerprint it leaves on the cosmos.

    “Gravity tells us a lot about how much dark matter is in the universe and the kinds of particle interactions dark sector particles can and cannot have,” Shelton says. “For instance, more sensitive gravitational-wave experiments will give us the possibility to look back in time and see what our universe looked like at extremely high energies, and could maybe reveal more about this invisible matter living in our cosmos.”

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:27 pm on January 16, 2018 Permalink | Reply
    Tags: , , , , , ,   

    From STFC: “UK builds vital component of global neutrino experiment” 


    STFC

    16 January 2018
    Becky Parker-Ellis
    becky.parker-ellis@stfc.ac.uk
    Tel: +44(0)1793 444564
    Mob: +44(0)7808 879294

    1
    The APA being prepped for shipment at Daresbury Laboratory. (Credit: STFC)

    The UK has built an essential piece of the globally-anticipated DUNE experiment, which will study the differences between neutrinos and anti-neutrinos in a bid to understand how the Universe came to be made up of matter.

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


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    Vital components of the DUNE detectors have been constructed in the UK and have now been shipped to CERN for initial testing, marking a significant milestone for the experiment’s progress.

    DUNE (the Deep Underground Neutrino Experiment) is a flagship international experiment run by the United States Department of Energy’s Fermilab [FNAL] that involves over 1,000 scientists from 31 countries. Various elements of the experiment are under construction across the world, with the UK taking a major role in contributing essential expertise and components to the experiment and facility.

    Using a particle accelerator, an intense beam of neutrinos will be fired 800 miles through the earth from Fermilab in Chicago to the DUNE experiment in South Dakota. There the incoming beam will be studied using DUNE’s liquid-argon detector.

    The DUNE project aims to advance our understanding of the origin and structure of the universe. One aspect of study is the behaviour of particles called neutrinos and their antimatter counterparts, antineutrinos. This could provide insight as to why we live in a matter-dominated universe and inform the debate on why the universe survived the Big Bang.

    A UK team has just completed their first prototype Anode Plane Assembly (APA), the largest component of the DUNE detector, to be used in the protoDUNE detector at CERN.

    2
    First APA (Anode Plane Assembly) ready to be installed in the protoDUNE-SP detector Photograph: Ordan, Julien Marius

    CERN Proto DUNE Maximillian Brice

    The APA, which was built at the Science and Technology Facilities Council’s (STFC) Daresbury Laboratory, is the first such anode plane to ever have been built in the UK.

    The APAs are large rectangular steel frames covered with approximately 4000 wires that are used to read the signal from particle tracks generated inside the liquid-argon detector. At 2.3m by 6.3m, the impressive frames are roughly as large as five full-size pool tables led side-by-side.

    Dr Justin Evans of the University of Manchester, who is leading the protoDUNE APA-construction project in the UK, said: “This shipment marks the culmination of a year of very hard work by the team, which has members from STFC Daresbury and the Universities of Manchester, Liverpool, Sheffield and Lancaster. Constructing this anode plane has required relentless attention to detail, and huge dedication to addressing the challenges of building something for the first time. This is a major milestone on our way to doing exciting physics with the protoDUNE and DUNE detectors.”

    These prototype frames were funded through an STFC grant. The 150 APAs that the UK will produce for the large-scale DUNE detector will be paid for as part of the £65million investment by the UK in the UK-US Science and Technology agreement, which was announced in September last year.

    Mechanical engineer Alan Grant has led the organisation of the project on behalf of STFC’s Daresbury Laboratory. He said: “This is an exciting milestone for the UK’s contribution to the DUNE project.

    “The planes are a vital part of the liquid-argon detectors and are one of the biggest component contributions the UK is making to DUNE, so it is thrilling to have the first one ready for shipping and testing.

    “We have a busy few years ahead of us at the Daresbury Laboratory as we are planning to build 150 panels for one of DUNE’s modules, but we are looking forward to meeting the challenge.”

    3
    The ProtoDUNE core installation team members at CERN, in front of the truck from Daresbury. (Credit: University of Liverpool)

    The UK’s first complete APA began the long journey to CERN by road on Friday (January 12), and arrived in Geneva today (January 16). Once successfully tested on the protoDUNE experiment at CERN, a full set of panels will be created and eventually be installed one-mile underground at Fermilab’s Long-Baseline Neutrino Facility (LBNF) in the Sanford Underground Research Facility in South Dakota.

    This is the first such plane to be delivered by the UK to CERN for testing, with the second and third panels set to be shipped in spring. It is expected to take two to three years to produce the full 150 APAs for one module.

    Professor Alfons Weber, of STFC and Oxford University, is the overall Principal Investigator of DUNE UK. He said: “We in the UK are gearing up to deliver several major components for the DUNE experiment and the LBNF facility, which also include the data acquisition system, accelerator components and the neutrino production target. These prototype APAs, which will be installed and tested at CERN, are one of the first major deliveries that will make this exciting experiment a reality.”

    The DUNE APA consortium is led by Professor Stefan Söldner-Rembold of the University of Manchester, with contributions from several other North West universities including Liverpool, Sheffield and Lancaster.

    Professor Söldner-Rembold said: “Each one of the four final DUNE modules will contain 17,000 tons of liquid argon. For a single module, 150 APAs will need to be built which represents a major construction challenge. We are working with UK industry to prepare this large construction project. The wires are kept under tension and we need to ensure that none of the wires will break during several decades of detector operation as the inside of the detector will not be accessible. The planes will now undergo rigorous testing to make sure they are up for the job.

    “Physicists across the world are excited to see what DUNE will be capable of, as unlocking the secrets of the neutrino will help us understand more about the structure of the Universe.

    “Although neutrinos are the second most abundant particle in the Universe, they are enormously difficult to catch as they have very nearly no mass, are not charged and rarely interact with other particles. This is why DUNE is such an exciting experiment and why we are celebrating this milestone in its construction.”

    Christos Touramanis, from the University of Liverpool and co-spokesperson for the protoDUNE project, said: “ProtoDUNE is the first CERN experiment which is a prototype for an experiment at Fermilab, a demonstration of global strategy and coordination in modern particle physics. We in the UK have been instrumental in setting up protoDUNE and in addition to my role we provide leadership in the data acquisition sub-project, and of course anode planes.”

    DUNE will also watch for neutrinos produced when a star explodes, which could reveal the formation of neutron stars and black holes, and will investigate whether protons live forever or eventually decay, bringing us closer to fulfilling Einstein’s dream of a grand unified theory.

    See the full article here .

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    STFC Hartree Centre

    Helping build a globally competitive, knowledge-based UK economy

    We are a world-leading multi-disciplinary science organisation, and our goal is to deliver economic, societal, scientific and international benefits to the UK and its people – and more broadly to the world. Our strength comes from our distinct but interrelated functions:

    Universities: we support university-based research, innovation and skills development in astronomy, particle physics, nuclear physics, and space science
    Scientific Facilities: we provide access to world-leading, large-scale facilities across a range of physical and life sciences, enabling research, innovation and skills training in these areas
    National Campuses: we work with partners to build National Science and Innovation Campuses based around our National Laboratories to promote academic and industrial collaboration and translation of our research to market through direct interaction with industry
    Inspiring and Involving: we help ensure a future pipeline of skilled and enthusiastic young people by using the excitement of our sciences to encourage wider take-up of STEM subjects in school and future life (science, technology, engineering and mathematics)

    We support an academic community of around 1,700 in particle physics, nuclear physics, and astronomy including space science, who work at more than 50 universities and research institutes in the UK, Europe, Japan and the United States, including a rolling cohort of more than 900 PhD students.

    STFC-funded universities produce physics postgraduates with outstanding high-end scientific, analytic and technical skills who on graduation enjoy almost full employment. Roughly half of our PhD students continue in research, sustaining national capability and creating the bedrock of the UK’s scientific excellence. The remainder – much valued for their numerical, problem solving and project management skills – choose equally important industrial, commercial or government careers.

    Our large-scale scientific facilities in the UK and Europe are used by more than 3,500 users each year, carrying out more than 2,000 experiments and generating around 900 publications. The facilities provide a range of research techniques using neutrons, muons, lasers and x-rays, and high performance computing and complex analysis of large data sets.

    They are used by scientists across a huge variety of science disciplines ranging from the physical and heritage sciences to medicine, biosciences, the environment, energy, and more. These facilities provide a massive productivity boost for UK science, as well as unique capabilities for UK industry.

    Our two Campuses are based around our Rutherford Appleton Laboratory at Harwell in Oxfordshire, and our Daresbury Laboratory in Cheshire – each of which offers a different cluster of technological expertise that underpins and ties together diverse research fields.

    The combination of access to world-class research facilities and scientists, office and laboratory space, business support, and an environment which encourages innovation has proven a compelling combination, attracting start-ups, SMEs and large blue chips such as IBM and Unilever.

    We think our science is awesome – and we know students, teachers and parents think so too. That’s why we run an extensive Public Engagement and science communication programme, ranging from loans to schools of Moon Rocks, funding support for academics to inspire more young people, embedding public engagement in our funded grant programme, and running a series of lectures, travelling exhibitions and visits to our sites across the year.

    Ninety per cent of physics undergraduates say that they were attracted to the course by our sciences, and applications for physics courses are up – despite an overall decline in university enrolment.

     
  • richardmitnick 1:58 pm on January 16, 2018 Permalink | Reply
    Tags: , , , , , , , , , QUB-Queens University Belfast, , ,   

    From QUB via The Conversation: “How we created a mini ‘gamma ray burst’ in the lab for the first time” 

    QUB bloc

    Queens University Belfast (QUB)

    The Conversation

    January 15, 2018
    GIANLUCA SARRI

    Gamma ray bursts, intense explosions of light, are the brightest events ever observed in the universe – lasting no longer than seconds or minutes. Some are so luminous that they can be observed with the naked eye, such as the burst “GRB 080319B” discovered by NASA’s Swift GRB Explorer mission on March 19, 2008.

    NASA Neil Gehrels Swift Observatory

    But despite the fact that they are so intense, scientists don’t really know what causes gamma ray bursts. There are even people who believe some of them might be messages sent from advanced alien civilisations. Now we have for the first time managed to recreate a mini version of a gamma ray burst in the laboratory – opening up a whole new way to investigate their properties. Our research is published in Physical Review Letters.

    One idea for the origin of gamma ray bursts [Science] is that they are somehow emitted during the emission of jets of particles released by massive astrophysical objects, such as black holes. This makes gamma ray bursts extremely interesting to astrophysicists – their detailed study can unveil some key properties of the black holes they originate from.

    The beams released by the black holes would be mostly composed of electrons and their “antimatter” companions, the positrons – all particle have antimatter counterparts that are exactly identical to themselves, only with opposite charge. These beams must have strong, self-generated magnetic fields. The rotation of these particles around the fields give off powerful bursts of gamma ray radiation. Or, at least, this is what our theories predict [MNRAS]. But we don’t actually know how the fields would be generated.

    Unfortunately, there are a couple of problems in studying these bursts. Not only do they last for short periods of time but, most problematically, they are originated in distant galaxies, sometimes even billion light years from Earth (imagine a one followed by 25 zeroes – this is basically what one billion light years is in metres).

    That means you rely on looking at something unbelievably far away that happens at random, and lasts only for few seconds. It is a bit like understanding what a candle is made of, by only having glimpses of candles being lit up from time to time thousands of kilometres from you.

    World’s most powerful laser

    It has been recently proposed that the best way to work out how gamma ray bursts are produced would be by mimicking them in small-scale reproductions in the laboratory – reproducing a little source of these electron-positron beams and look at how they evolve when left on their own. Our group and our collaborators from the US, France, UK, and Sweden, recently succeeded in creating the first small-scale replica of this phenomenon by using one of the most intense lasers on Earth, the Gemini laser, hosted by the Rutherford Appleton Laboratory in the UK.

    1
    The Gemini laser, hosted by the Rutherford Appleton Laboratory in the UK.

    How intense is the most intense laser on Earth? Take all the solar power that hits the whole Earth and squeeze it into a few microns (basically the thickness of a human hair) and you have got the intensity of a typical laser shot in Gemini. Shooting this laser onto a complex target, we were able to release ultra-fast and dense copies of these astrophysical jets and make ultra-fast movies of how they behave. The scaling down of these experiments is dramatic: take a real jet that extends even for thousands of light years and compress it down to a few millimetres.

    In our experiment, we were able to observe, for the first time, some of the key phenomena that play a major role in the generation of gamma ray bursts, such as the self-generation of magnetic fields that lasted for a long time. These were able to confirm some major theoretical predictions of the strength and distribution of these fields. In short, our experiment independently confirms that the models currently used to understand gamma ray bursts are on the right track.

    The experiment is not only important for studying gamma ray bursts. Matter made only of electrons and positrons is an extremely peculiar state of matter. Normal matter on Earth is predominantly made of atoms: a heavy positive nucleus surrounded by clouds of light and negative electrons.

    2
    Artist impression of gamma ray burst. NASA [no additional credit for which facility or which artist].

    Due to the incredible difference in weight between these two components (the lightest nucleus weighs 1836 times the electron) almost all the phenomena we experience in our everyday life comes from the dynamics of electrons, which are much quicker in responding to any external input (light, other particles, magnetic fields, you name it) than nuclei. But in an electron-positron beam, both particles have exactly the same mass, meaning that this disparity in reaction times is completely obliterated. This brings to a quantity of fascinating consequences. For example, sound would not exist in an electron-positron world.

    So far so good, but why should we care so much about events that are so distant? There are multiple reasons indeed. First, understanding how gamma ray bursts are formed will allow us to understand a lot more about black holes and thus open a big window on how our universe was born and how it will evolve.

    But there is a more subtle reason. SETI – Search for Extra-Terrestrial Intelligence – looks for messages from alien civilisations by trying to capture electromagnetic signals from space that cannot be explained naturally (it focuses mainly on radio waves, but gamma ray bursts are associated with such radiation too).

    Breakthrough Listen Project

    1

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA



    GBO radio telescope, Green Bank, West Virginia, USA


    CSIRO/Parkes Observatory, located 20 kilometres north of the town of Parkes, New South Wales, Australia

    U Manchester Jodrell Bank Lovell Telescope


    SETI@home, BOINC project at UC Berkeley Space Science Lab

    Laser SETI, the future of SETI Institute research

    Of course, if you put your detector to look for emissions from space, you do get an awful lot of different signals. If you really want to isolate intelligent transmissions, you first need to make sure all the natural emissions are perfectly known so that they can excluded. Our study helps towards understanding black hole and pulsar emissions, so that, whenever we detect anything similar, we know that it is not coming from an alien civilisation.

    See the full article here .

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    QUB campus

    An international institution

    Queen’s is in the top one per cent of global universities.

    With more than 23,000 students and 3,700 staff, it is a dynamic and diverse institution, a magnet for inward investment, a major employer and investor, a patron of the arts and a global player in areas ranging from cancer studies to sustainability, and from pharmaceuticals to creative writing.
    World-leading research

    Queen’s is a member of the Russell Group of 24 leading UK research-intensive universities, alongside Oxford, Cambridge and Imperial College London.

    In the UK top ten for research intensity

    The Research Excellence Framework (REF) 2014 results placed Queen’s joint 8th in the UK for research intensity, with over 75 per cent of Queen’s researchers undertaking world-class or internationally leading research.

    The University also has 14 subject areas ranked within the UK’s top 20 and 76 per cent of its research classified in the top two categories of world leading and internationally excellent.

    This validates Queen’s as a University with world-class researchers carrying out world-class or internationally leading research.

    Globally recognised education

    The University has won the Queen’s Anniversary Prize for Higher and Further Education on five occasions – for Northern Ireland’s Comprehensive Cancer Services programme and for world-class achievement in green chemistry, environmental research, palaeoecology and law.

     
  • richardmitnick 1:10 pm on January 16, 2018 Permalink | Reply
    Tags: Chirality or “handedness”, , , X-Rays Reveal ‘Handedness’ in Swirling Electric Vortices   

    From LBNL: “X-Rays Reveal ‘Handedness’ in Swirling Electric Vortices” 

    Berkeley Logo

    Berkeley Lab

    January 15, 2018
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    1
    Just as people can be left-handed or right-handed, scientists have observed chirality or “handedness” in swirling electric vortices in a layered material. (Credit: Pixabay)

    Scientists used spiraling X-rays at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) to observe, for the first time, a property that gives handedness to swirling electric patterns – dubbed polar vortices – in a synthetically layered material.

    This property, also known as chirality, potentially opens up a new way to store data by controlling the left- or right-handedness in the material’s array in much the same way magnetic materials are manipulated to store data as ones or zeros in a computer’s memory.

    Researchers said the behavior also could be explored for coupling to magnetic or optical (light-based) devices, which could allow better control via electrical switching.

    Chirality is present in many forms and at many scales, from the spiral-staircase design of our own DNA to the spin and drift of spiral galaxies; it can even determine whether a molecule acts as a medicine or a poison in our bodies.

    A molecular compound known as d-glucose, for example, which is an essential ingredient for human life as a form of sugar, exhibits right-handedness. Its left-handed counterpart, l-glucose, though, is not useful in human biology.

    “Chirality hadn’t been seen before in this electric structure,” said Elke Arenholz, a senior staff scientist at Berkeley Lab’s Advanced Light Source (ALS), which is home to the X-rays that were key to the study, published Jan. 15 in the journal Proceedings of the National Academy of Sciences.

    LBNL/ALS

    The experiments can distinguish between left-handed chirality and right-handed chirality in the samples’ vortices. “This offers new opportunities for fundamentally new science, with the potential to open up applications,” she said.

    “Imagine that one could convert a right-handed form of a molecule to its left-handed form by applying an electric field, or artificially engineer a material with a particular chirality,” said Ramamoorthy Ramesh, a faculty senior scientist in Berkeley Lab’s Materials Sciences Division and associate laboratory director of the Lab’s Energy Technologies Area, who co-led the latest study.

    Ramesh, who is also a professor of materials science and physics at UC Berkeley, custom-made the novel materials at UC Berkeley.

    Padraic Shafer, a research scientist at the ALS and the lead author of the study, worked with Arenholz to carry out the X-ray experiments that revealed the chirality of the material.

    The samples included a layer of lead titanate (PbTiO3) and a layer of strontium titanate (SrTiO3) sandwiched together in an alternating pattern to form a material known as a superlattice. The materials have also been studied for their tunable electrical properties that make them candidates for components in precise sensors and for other uses.

    2
    This diagram shows the setup for the X-ray experiment that explored chirality, or handedness, in a layered material. The blue and red spirals at upper left show the X-ray light that was used to probe the material. The X-rays scattered off of the layers of the material (arrows at upper right and associated X-ray images at top), allowing researchers to measure chirality in swirling electrical vortices within the material. (Credit: Berkeley Lab)

    Neither of the two compounds show any handedness by themselves, but when they were combined into the precisely layered superlattice, they developed the swirling vortex structures that exhibited chirality.

    “Chirality may have additional functionality,” Shafer said, when compared to devices that use magnetic fields to rearrange the magnetic structure of the material.

    The electronic patterns in the material that were studied at the ALS were first revealed using a powerful electron microscope at Berkeley Lab’s National Center for Electron Microscopy, a part of the Lab’s Molecular Foundry, though it took a specialized X-ray technique to identify their chirality.

    “The X-ray measurements had to be performed in extreme geometries that can’t be done by most experimental equipment,” Shafer said, using a technique known as resonant soft X-ray diffraction that probes periodic nanometer-scale details in their electronic structure and properties.

    Spiraling forms of X-rays, known as circularly polarized X-rays, allowed researchers to measure both left-handed and right-handed chirality in the samples.

    Arenholz, who is also a faculty member of the UC Berkeley Department of Materials Science & Engineering, added, “It took a lot of time to understand the results, and a lot of modeling and discussions.” Theorists at the University of Cantabria in Spain and their network of computational experts performed calculations of the vortex structures that aided in the interpretation of the X-ray data.

    The same science team is pursuing studies of other types and combinations of materials to test the effects on chirality and other properties.

    “There is a wide class of materials that could be substituted,” Shafer said, “and there is the hope that the layers could be replaced with even higher functionality materials.”

    Researchers also plan to test whether there are new ways to control the chirality in these layered materials, such as by combining materials that have electrically switchable properties with those that exhibit magnetically switchable properties.

    “Since we know so much about magnetic structures,” Arenholz said, “we could think of using this well-known connection with magnetism to implement this newly discovered property into devices.”

    The Advanced Light Source and the Molecular Foundry are both DOE Office of Science User Facilities.

    Also participating in the research were scientists from the UC Berkeley Department of Electrical Engineering and Computer Sciences, the Institute of Materials Science of Barcelona, the University of the Basque Country, and the Luxembourg Institute of Science and Technology. The work was supported by the U.S. Department of Energy Office of Science, the National Science Foundation, the Luxembourg National Research Fund, the Spanish Ministry of Economy and Competitiveness, and the Gordon and Betty Moore Foundation.

    See the full article here .

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  • richardmitnick 12:36 pm on January 16, 2018 Permalink | Reply
    Tags: , , , , , , ,   

    From ESO: “Introduction to ALMA – In search of our cosmic origins” 

    ESO 50 Large

    European Southern Observatory

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    What is the Atacama Large Millimeter/submillimeter Array (ALMA)?

    High on the Chajnantor plateau in the Chilean Andes, the European Southern Observatory (ESO), together with its international partners, is operating the Atacama Large Millimeter/submillimeter Array (ALMA) — a state-of-the-art telescope to study light from some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves, and is therefore known as millimetre and submillimetre radiation. ALMA comprises 66 high-precision antennas, spread over distances of up to 16 kilometres. This global collaboration is the largest ground-based astronomical project in existence.

    1
    ALMA roadmap. Credit: ESO

    _____________________________________________________________
    ALMA
    Name: Atacama Large Millimeter/submillimeter Array
    Site: Chajnantor
    Altitude: 4576 to 5044m (most above 5000 m)
    Enclosure: Open air
    Type: Sub-millimeter interferometer antenna array
    Optical design: Cassegrain
    Diameter. Primary M1: 54 x 12.0 m (AEM, Vertex, and MELCO) and 12 x 7.0 m (MELCO)
    Material. Primary M1: CFRP and Aluminium (12-metre),Steel and Aluminium (7-metre)
    Diameter. Secondary M2: 0.75 m (for 12-metre antennas); 0.457 m (for 7-metre antennas)
    Material. Secondary M2: Aluminium
    Mount: Alt-Azimuth mount
    First Light date: 30 September 2011
    Interferometry: Click on the image to take a Virtual Tour in and nearby Chajnantor.Click on the image to take a Virtual Tour in and nearby Chajnantor.Baselines from 150 m to 16 km

    _____________________________________________________________

    What is submillimetre astronomy?

    Light at these wavelengths comes from vast cold clouds in interstellar space, at temperatures only a few tens of degrees above absolute zero, and from some of the earliest and most distant galaxies in the Universe. Astronomers can use it to study the chemical and physical conditions in molecular clouds — the dense regions of gas and dust where new stars are being born. Often these regions of the Universe are dark and obscured in visible light, but they shine brightly in the millimetre and submillimetre part of the spectrum.

    Why build ALMA in the high Andes?

    Millimetre and submillimetre radiation opens a window into the enigmatic cold Universe, but the signals from space are heavily absorbed by water vapour in the Earth’s atmosphere. Telescopes for this kind of astronomy must be built on high, dry sites, such as the 5000-m high plateau at Chajnantor, one of the highest astronomical observatory sites on Earth.

    The ALMA site, some 50 km east of San Pedro de Atacama in northern Chile, is in one of the driest places on Earth. Astronomers find unsurpassed conditions for observing, but they must operate a frontier observatory under very difficult conditions. Chajnantor is more than 750 m higher than the observatories on Mauna Kea, and 2400 m higher than the VLT on Cerro Paranal.

    2
    Click on the image to take a Virtual Tour in and nearby Chajnantor [in the full article].

    Why is ALMA an interferometer?

    ALMA is a single telescope of revolutionary design, composed initially of 66 high-precision antennas, and operating at wavelengths of 0.32 to 3.6 mm. Its main 12-metre array has fifty antennas, 12 metres in diameter, acting together as a single telescope — an interferometer. An additional compact array of four 12-metre and twelve 7-metre antennas complements this. The 66 ALMA antennas can be arranged in different configurations, where the maximum distance between antennas can vary from 150 metres to 16 kilometres, which give ALMA a powerful variable “zoom”. It is be able to probe the Universe at millimetre and submillimetre wavelengths with unprecedented sensitivity and resolution, with a vision up to ten times sharper than the Hubble Space Telescope, and complementing images made with the VLT Interferometer.

    Science with ALMA

    3

    ALMA is the most powerful telescope for observing the cool Universe — molecular gas and dust. ALMA studies the building blocks of stars, planetary systems, galaxies and life itself. By providing scientists with detailed images of stars and planets being born in gas clouds near our Solar System, and detecting distant galaxies forming at the edge of the observable Universe, which we see as they were roughly ten billion years ago, it lets astronomers address some of the deepest questions of our cosmic origins.

    ALMA was inaugurated in 2013, but early scientific observations with a partial array began in 2011. See press release eso1137 for more information.

    ALMA has consistenly produced unique and spectacular results. The fields in which it has delivered its most outstanding results include:

    Providing images of protoplanetary disks such as HL Tau (see eso1436) which transformed the previously accepted theories about the planetary formation.
    Observing phenomena such as Einstein Rings in extraordinary detail (see eso1522), providing a level of resolution not acheived by the NASA/ESA Hubble Space Telescope.
    The detection of complex organic molecules — carbon-based, pre-biotic structures, necessary for building life — in distant protoplanetary disks (see eso1513), comfirming that our Solar System is not unique in potentially fostering life.

    For more information on discoveries made with ALMA, explore the Science with ESO Telescopes page.

    ALMA is a partnership of the ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

    ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    Science goals

    Star formation, molecular clouds, early Universe.

    More about the ALMA Observatory

    ALMA Antennas
    ALMA Transporters
    ALMA and Interferometry
    ALMA Residencia
    More interesting facts are available on the FAQs page
    Read more about this observatory on the ALMA Handout in PDF format
    More ALMA Image Archive and ALMA Video Archive are available in the ESO multimedia archive
    For scientists: for more detailed information, please visit our technical pages
    Visit the ALMA Observatory website

    The ALMA Planetarium Show

    “In search of our Cosmic Origins” is an inspiring show, introducing ALMA, the largest astronomical project in existence. Read more at the Cosmic Origins website.

    See the full article here .

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level.

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level.

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

     
  • richardmitnick 7:37 am on January 16, 2018 Permalink | Reply
    Tags: , , , , , How habitable is your galaxy?   

    From astrobites: “How habitable is your galaxy?” 

    Astrobites bloc

    astrobites

    Jan 16, 2018
    Matthew Green

    Title: Exploring the Cosmic Evolution of Habitability with Galaxy Merger Trees
    Authors: E. R. Stanway, M. J. Hoskin, M. A. Lane et al.
    First Author’s Institution: Department of Physics, University of Warwick, Coventry, UK

    Status: Accepted to MNRAS, open access

    1
    Figure 1: The Antennae Galaxies, two galaxies which are in the process of merging. The bright blue regions are undergoing bursts of star formation triggered by the merger. Source: ESO/L. Calçada

    When we talk about the habitability of a planet, astronomers are normally referring to one thing: whether a planet’s temperature is right for life. This comes down to a planet’s relationship to its host star — how hot the star is, and how far away the planet is from the star. Of course, there are a whole host of other factors at play regarding whether life could evolve on a planet or not — some that we know about and undoubtedly many that we don’t. As our understanding increases, the conversation is widening to include some of these other factors (for instance, what impact X-rays or flares from the host star will have). Today’s paper takes a broader view, by looking at habitability not on the level of stars and planets, but on the level of galaxies. It turns out that both the nature of the galaxy you’re in and where you are within it are important questions for any aspiring life-forms.

    See the full article here .

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    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 5:31 pm on January 15, 2018 Permalink | Reply
    Tags: , , , , ,   

    From Many Worlds: “Putting Together a Community Strategy To Search for Extraterrestrial Life” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2018-01-15
    Marc Kaufman

    1
    The scientific search underway for life beyond Earth requires input from many disciplines and fields. Strategies forward have to hear and take in what scientists in those many fields have to say. (NASA)

    Behind the front page space science discoveries that tell us about the intricacies and wonders of our world are generally years of technical and intellectual development, years of planning and refining, years of problem-defining and problem-solving. And before all this, there also years of brainstorming, analysis and strategizing about which science goals should have the highest priorities and which might be most attainable.

    That latter process is underway now in regarding the search for life in the solar system and beyond, with numerous teams of scientists tackling specific areas of interest and concern and turning their group discussions into white papers. In this case, the white papers will then go on to the National Academy of Sciences for a blue-ribbon panel review and ultimately recommendations on which subjects are exciting and mature enough for inclusion in a decadal survey and possible funding.

    This is a generally little-known part of the process that results in discoveries, but scientists certainly understand how they are essential. That’s why hundreds of scientists contribute their ideas and time — often unpaid — to help put together these foundational documents.

    With its call for extraterrestrial habitability white papers, the NASA got more than 20 diverse and often deeply thought out offerings. The papers will be studied now by an ad hoc, blue ribbon committee of scientists selected by the NAS, which will have the first of two public meetings in Irvine, Calif. on Jan. 16-18.

    Then their recommendations go up further to the decadal survey teams that will set formal NASA priorities for the field of astronomy and astrophysics and planetary science. This community-based process that has worked well for many scientific disciplines since they began in the late 1950s.

    I’m particularly familiar with two of these white paper processes — one produced at the Earth-Life Science Institute (ELSI) in Tokyo and the other with NASA’s Nexus for Exoplanet System Science (NExSS.) What they have to say is most interesting.

    This is what Shawn Domagal-Goldman, an astrobiologist at the Goddard Space Flight Center, had to say about their effort, which began 16 months ago with a workshop in Seattle:

    “This is an ‘all-hands-on-deck’ problem, and we held a workshop to start drawing a wide variety of scientists to the problem. Once we did, the group gave itself an ambitious goal – to quantify an assessment of whether or not an exoplanet has life, based on remote observations of that world.

    “Doing that will take years of collaboration of scientists like the ones at the meeting, from diverse backgrounds and diverse experiences.”

    Chaitanya Giri, a research scientist at ELSI with a background in organic planetary chemistry and organic cosmochemistry, said that his work on the European Rosetta mission to a comet convinced him that it is essential to “develop technological capacities to explore habitable niches on various planetary bodies and find unambiguous signatures of life, if present.” There is some debate about the organic molecules — the chemical building blocks of life — identified by Rosetta.

    “Over the years there have been scattered attempts at building such instruments, but a coherent collaborative network was missing,” Giri said. “This necessity inspired me to put on this workshop,” which led to the white paper.

    We’ll discuss the conclusions of the papers, but first at little about the decadal surveys:

    2
    NASA Decada:

    Here are the instruction from the NAS to potential white paper teams working on life beyond Earth projects and issues:

    Identify promising key research goals in the field of the search for signs of life in which progress is likely in the next 20 years.
    Identify key technological challenges in astrobiology as they pertain to the search for life in the solar system and extrasolar planetary systems.
    Identify key scientific questions in astrobiology as they pertain to the search for life in the solar system and extrasolar planetary systems
    Discuss scientific advances that can be addressed by U.S. and international space missions and relevant ground-based activities in operation or funded and in development
    Discuss how to expand partnerships (interagency, international and public/private) in furthering the study of life’s origin, evolution, distribution, and future in the universe

    Quite a wide net, from specific issues to much broader ones. But the teams submitting their papers are not expected to address all the issues, but only one or perhaps a related second.
    The papers range from a SETI Institute call for a program to increase the use of artificial intelligence and machine learning to address a range of astrobiology issues; to tempting possibilities offered by teams already in the running for future missions to Europa or Enceladus or elsewhere; to recommendations from the Planetary Science Institute about studying and searching for microbialites, living carbonate rock structures once common on Earth and possibly on Mars as well.

    Proposed White Paper Subjects

    3
    Several white papers discussed the desirability of sending a proble to Saturn’s moon Enceladus. plume of water vapor flowing out from its South Pole. (NASA)

    4
    Microbialites are fresh water versions of the organic and carbonate structures called stromatolites — which are among the oldest signs of life detected on Earth.

    The white paper from ELSI focuses how to improve and discover technology that can detect potential life on other planets and moons. It calls for an increasingly international approach to that costly and specialized effort.

    The paper from Giri et al begins with a disquieting conclusion that only “lately,
    scattered efforts are being undertaken towards the R&D of the novel and as-yet space unproven
    ‘life-detection’ technologies capable of obtaining unambiguous evidence of
    extraterrestrial life, even if it is significantly different from {Earth} life. As the suite of
    space-proven payloads improves in breadth and sensitivity, this is an apt time to examine the
    progress and future of life-detection technologies.”
    The paper points to one discovery in particular as indicative of what the team feels is necessary — an ability to search for life in regions theoretically devoid of life and therefore requiring novel detection
    techniques or probes.
    “For example,” they write, “air sampling in Earth’s stratosphere with a novel
    scientific cryogenic payload has led to the isolation and identification of several new species
    of bacteria; this was an innovative technique analyzing a region of the atmosphere that was
    initially believed to be devoid of life.”
    Other technologies they see as promising and needing further development are high-sensitivity fluorescence microscopy techniques that may be able to detect extraterrestrial organic compounds with catalytic activity surrounded by membranes, i.e., extraterrestrial cells. In addition, they support on-going and NASA-funded work on genetic samplers that could go to Mars and — if present — actually identify nucleic acid-based life.
    “With back-to-back missions under development and proposed by various space agencies to the potentially habitable Mars, Enceladus, Titan, and Europa, this is a right time for a detailed envisioning of the technologies needed for detection of life,” Giri said in an e-mail.

    5
    Yellowknife Bay on Mars, where the rover Curiosity first found conditions that were habitable to life. The rover subsequently found many more habitable spots, but no existing or fossil life so far. (NASA)

    The NExSS white paper is an especially ambitious one, and focuses on potential biosignatures from distant exoplanets. The NASA-sponsored effort brought in many top scientists working in the field of biosignatures, and in the past year has already resulted in the publication or submission of five major science papers in addition to the white paper.
    In keeping with the interdisciplinary mission of NExSS, the paper brought in people from many fields and ultimately advocates for a Bayesian approach to exoplanet life detection (named after 18th century statistician and philosopher Thomas Bayes. )
    In most basic terms, the Bayes approach describes the probability of an event based on prior knowledge of conditions that might be related to the event. A simple example: Runners A and B have competed four times, and runner A won three times. So the probability of A winner is high, right? But what if the two competed twice on a rainy track and each won one race. If the forecast for the day of the next race is rain, the probability of who will be the winner would change.
    This approach not only embraces probability as an essential way forward, but it is especially useful in terms of weighing probabilities involving many measurements and fields. Because the factors involved in finding a biosignature are so complex and potentially confounding, they argue, the field has to think in terms of the probability that a number of biosignatures together suggest the presence of life, rather than a 100 percent certain detection (although that may some day be possible.)
    Both Domagal-Goldman and collaborator exoplanet photosynthesis expert Nancy Kiang of NASA’s Goddard Institute for Space Studies are eager to adopt climate modeling and it’s ability to use known characteristics of divergent sub-fields to put together a big picture.
    For instance, Kiang said, the Global Climate Modeling program at GISS simulates the circulation patterns of Earth’s wind, heat, moisture, and gases, and can make pretty good predictions of what climate conditions will result. She sees a similar possibility with exoplanets and biosignatures.
    Such a computer model can take in data from different fields and come up with some probabilities. The model “might tell us that a planet is habitable over a certain percent of its surface,” she said.
    “A geochemist or planetary formation person might then tell us that if certain chemistry exists on that planet, it has good potential for prebiotic compounds to form. A biologist and geologist might tell us that certain surface signatures on the planet are plausible for either life or mineral background.” That’s not a robust biosignature, but the probability that it could be life is not zero, depending on origin of the signature.
    “These different forms of information can be integrated into a Bayesian analysis to tell us the likelihood of life on the planet,” she wrote.
    One arm of the NExSS team is already using the tools of climate modeling to predict how particular conditions on exoplanets would play out under different circumstances.

    6
    This example of how Earth planet modeling can be used for exoplanets is a plot of what the sea ice distribution could look like on a synchronously rotating ocean world. The star is off to the right, blue is where there is open ocean, and white is where there is sea ice. (NASA/GISS/Anthony Del Genio)

    I will return to the NExSS biosignatures white paper later, since it is so rich with cutting edge thinking about this upcoming stage in space science. But I do want to include one specific recommendation made by what is called the Exoplanet Biosignatures Workshop Without Walls (EBWWW).
    What they say is necessary now is for more biologists to join the search for extraterrestrial life.
    “The EBWWW revealed that the search for exoplanet life is still largely driven by astronomers
    and planetary scientists, and that this field requires more input from origins of life researchers
    and biologists to advance a process-based understanding for planetary biosignatures.
    “This includes assessing the {already assessed probability} that a planet may have life, or a life process evolved for a given planet’s environment. These advances will require fundamental research into the origins and processes of life, in particular for environments that vary from modern Earth’s. Thus, collaboration between origins of life researchers, biologists, and planetary scientists is critical to defining research questions around environmental context.”
    The recommendation, it seems to me, illustrates both the infancy and the maturing of the field.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 4:40 pm on January 15, 2018 Permalink | Reply
    Tags: , , ESA’s Cluster quartet, , Solar wind plasma   

    From ESA: “Simulating turbulence in solar wind plasma” 

    ESA Space For Europe Banner

    European Space Agency

    15/01/2018

    1
    D. Perrone et al.

    Maybe you’re reading this caption while drinking a coffee. As you stir your drink with a spoon, vortices are produced in the liquid that decay into smaller eddies until they disappear entirely. This can be described as a cascade of vortices from large to small scales. Furthermore, the motion of the spoon brings the hot liquid into contact with the cooler air and so the heat from the coffee can escape more efficiently into the atmosphere, cooling it down.

    A similar effect occurs in space, in the electrically charged atomic particles – solar wind plasma – blown out by our Sun, but with one key difference: in space there is no air. Although the energy injected into the solar wind by the Sun is transferred to smaller scales in turbulent cascades, just like in your coffee, the temperature in the plasma is seen to increase because there is no cool air to stop it.

    How exactly the solar wind plasma is heated is a hot topic in space physics, because it is hotter than expected for an expanding gas and almost no collisions are present. Scientists have suggested that the cause of this heating may be hidden in the turbulent character of the solar wind plasma.

    Advanced supercomputer simulations are helping to understand these complex motions: the image shown here is from one such simulation. [I have objected that there is no credit given for the supercomputer(s) involved in this work. Supercomputers are publicly and privately funded and deserve to be properly credited.] It represents the distribution of the current density in the turbulent solar wind plasma, where localised filaments and vortices have appeared as a consequence of the turbulent energy cascade. The blue and yellow colours show the most intense currents (blue for negative and yellow for positive values).

    These coherent structures are not static, but evolve in time and interact with each other. Moreover, between the islands, the current becomes very intense, creating high magnetic stress regions and sometimes a phenomenon known as magnetic reconnection. That is, when magnetic field lines of opposite direction get close together they can suddenly realign into new configurations, releasing vast amounts of energy that can cause localised heating.

    Such events are observed in space, for example by ESA’s Cluster quartet of satellites in Earth orbit, in the solar wind.

    ESA/Cluster

    Cluster also found evidence for turbulent eddies down to a few tens of kilometres as the solar wind interacts with Earth’s magnetic field.

    This cascade of energy may contribute to the overall heating of the solar wind, a topic that ESA’s future Solar Orbiter mission will also try to address.

    In the meantime, enjoy studying turbulent cascades of vortices in your coffee!

    More information: Perrone et al. (2013); Servidio et al. (2015), Valentini et al. (2016) and Perrone et al (2017).

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

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

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