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  • richardmitnick 8:33 pm on November 16, 2017 Permalink | Reply
    Tags: , , , , phys.org   

    From phys.org: “Machine learning used to predict earthquakes in a lab setting” 

    physdotorg
    phys.org

    October 23, 2017

    1
    Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles. Credit: Wikipedia.

    A group of researchers from the UK and the US have used machine learning techniques to successfully predict earthquakes. Although their work was performed in a laboratory setting, the experiment closely mimics real-life conditions, and the results could be used to predict the timing of a real earthquake.

    The team, from the University of Cambridge, Los Alamos National Laboratory and Boston University, identified a hidden signal leading up to earthquakes, and used this ‘fingerprint’ to train a machine learning algorithm to predict future earthquakes. Their results, which could also be applied to avalanches, landslides and more, are reported in the journal Geophysical Review Letters.

    For geoscientists, predicting the timing and magnitude of an earthquake is a fundamental goal. Generally speaking, pinpointing where an earthquake will occur is fairly straightforward: if an earthquake has struck a particular place before, the chances are it will strike there again. The questions that have challenged scientists for decades are how to pinpoint when an earthquake will occur, and how severe it will be. Over the past 15 years, advances in instrument precision have been made, but a reliable earthquake prediction technique has not yet been developed.

    As part of a project searching for ways to use machine learning techniques to make gallium nitride (GaN) LEDs more efficient, the study’s first author, Bertrand Rouet-Leduc, who was then a PhD student at Cambridge, moved to Los Alamos National Laboratory in New Mexico to start a collaboration on machine learning in materials science between Cambridge University and Los Alamos. From there the team started helping the Los Alamos Geophysics group on machine learning questions.

    The team at Los Alamos, led by Paul Johnson, studies the interactions among earthquakes, precursor quakes (often very small earth movements) and faults, with the hope of developing a method to predict earthquakes. Using a lab-based system that mimics real earthquakes, the researchers used machine learning techniques to analyse the acoustic signals coming from the ‘fault’ as it moved and search for patterns.

    The laboratory apparatus uses steel blocks to closely mimic the physical forces at work in a real earthquake, and also records the seismic signals and sounds that are emitted. Machine learning is then used to find the relationship between the acoustic signal coming from the fault and how close it is to failing.

    The machine learning algorithm was able to identify a particular pattern in the sound, previously thought to be nothing more than noise, which occurs long before an earthquake. The characteristics of this sound pattern can be used to give a precise estimate (within a few percent) of the stress on the fault (that is, how much force is it under) and to estimate the time remaining before failure, which gets more and more precise as failure approaches. The team now thinks that this sound pattern is a direct measure of the elastic energy that is in the system at a given time.

    “This is the first time that machine learning has been used to analyse acoustic data to predict when an earthquake will occur, long before it does, so that plenty of warning time can be given – it’s incredible what machine learning can do,” said co-author Professor Sir Colin Humphreys of Cambridge’s Department of Materials Science & Metallurgy, whose main area of research is energy-efficient and cost-effective LEDs. Humphreys was Rouet-Leduc’s supervisor when he was a PhD student at Cambridge.

    “Machine learning enables the analysis of datasets too large to handle manually and looks at data in an unbiased way that enables discoveries to be made,” said Rouet-Leduc.

    Although the researchers caution that there are multiple differences between a lab-based experiment and a real earthquake, they hope to progressively scale up their approach by applying it to real systems which most resemble their lab system. One such site is in California along the San Andreas Fault, where characteristic small repeating earthquakes are similar to those in the lab-based earthquake simulator. Progress is also being made on the Cascadia fault in the Pacific Northwest of the United States and British Columbia, Canada, where repeating slow earthquakes that occur over weeks or months are also very similar to laboratory earthquakes.

    “We’re at a point where huge advances in instrumentation, machine learning, faster computers and our ability to handle massive data sets could bring about huge advances in earthquake science,” said Rouet-Leduc.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

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  • richardmitnick 3:37 pm on November 1, 2017 Permalink | Reply
    Tags: , , , , , Milky Way Dark Matter Halo, phys.org,   

    From phys.org: “One step closer to defining dark matter, GPS satellite atomic clocks on the hunt” 

    physdotorg
    phys.org

    November 1, 2017

    1
    Physics professors Andrei Derevianko, left, and Geoff Blewitt of the University of Nevada, Reno College of Science, explain their research to discover how to detect dark matter, and ultimately to define more accurately what kind of particle it is. Credit: Mike Wolterbeek, University of Nevada, Reno

    One professor who studies the earth and one who studies space came together in the pursuit to detect and define dark matter. They are one step closer. Using 16 years of archival data from GPS satellites that that orbit the earth, the University of Nevada, Reno team, Andrei Derevianko and Geoff Blewitt in the College of Science, looked for dark matter clumps in the shape of walls or bubbles and which would extend far out beyond the GPS orbits, the solar system and beyond.

    A scientific article of the team’s work was just published in the journal Nature Communications and just in time for Dark Matter Day, Oct. 31. Dark matter makes up 85 percent of all matter in the universe. While there are multiple astrophysical evidences for dark matter, its nature remains a great mystery. Many forms for dark matter have been hypothesized, theirs is that this form of dark matter, arising from ultralight quantum fields, would form macroscopic objects.

    “We are another step closer to discovering how to detect dark matter, and ultimately to define more accurately what it is, what kind of particle it is” Derevianko said. “Mining these archival data, we found no evidence for domain walls of ultralight dark matter at our current sensitivity level. However, this search rules out a vast region of possibilities for this type of dark matter models.”

    The team focused on ultralight fields that might cause variations in the fundamental constants of nature – such as masses of electrons and quarks and electric charges. The variations could lead to shifts in atomic energy levels, which may be measurable by monitoring atomic frequencies. That’s where the GPS satellites come in. Global positioning system navigation relies on precision timing signals furnished by atomic clocks.

    “Geoff has been using the atomic clocks on the GPS satellites in his geodetic work – measuring uplift of tectonic plates, the shape of the earth, earthquakes, global sea levels, so is familiar with the precision of the system,” Derevianko said. “I’ve worked on devising more accurate atomic clocks. We realized the GPS system could be used to detect listen to the dark matter sweeping through us.

    “Instead of spending billions of dollars to eliminate some plausible dark mater models, we repurposed these common tools (GPS atomic clocks) we use every day to do basic, fundamental science to look for the answers to this great mystery – to devise our own planet-sized dark matter detector.”

    Speeding through the galaxy

    The Earth is speeding through the Milky Way dark matter halo at 300 kilometers per second or one-one thousandth the speed of light. And dark matter clumps are estimated to take 3 minutes to cross the GPS constellation.

    2
    Milky Way Dark Matter Halo – CERN

    “It’s like a wall moving through a network of clocks causing a wave of atomic clock glitches propagating through the GPS system at galactic speeds,” Derevianko, a professor of quantum physics, said. “The idea is that when the clump overlaps with us, it pulls on the particle masses and forces acting between the particles. Mind you this pull is really weak, otherwise we would have noticed it. However, ultra-sensitive devices like atomic clocks could be sensitive to such pulls.”

    They looked for the predicted patterns of clock glitches, as the earth, and the satellites, moved through the halo of dark matter in the galaxy. The data came from the 32 satellites in the 31,000-mile-wide GPS network and ground-based GPS equipment, every 30-seconds for 16 years. The team used data from sources around the world and in particular from the Jet Propulsion Laboratory.

    “What we looked for was clumps of dark matter in the shape of walls, using a model that – if it exists – would have collisions that are evidenced in irregularities in the atomic clock signals,” Benjamin Roberts, post-doctoral associate and lead author for the Nature paper, said. “While there is no definitive evidence after looking at 16 years of data, it could be that the interaction is weaker or that the defects cross paths with the Earth less often. Some markers indicate it could possibly be a smaller defect.”

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

     
  • richardmitnick 6:23 am on October 24, 2017 Permalink | Reply
    Tags: , , , , , , phys.org   

    From phys.org: “Artificial intelligence finds 56 new gravitational lens candidates” 

    physdotorg
    phys.org

    October 23, 2017

    1
    This picture shows a sample of the handmade photos of gravitational lenses that the astronomers used to train their neural network. Credit: Enrico Petrillo, University of Groningen

    A group of astronomers from the universities of Groningen, Naples and Bonn has developed a method that finds gravitational lenses in enormous piles of observations. The method is based on the same artificial intelligence algorithm that Google, Facebook and Tesla have been using in the last years. The researchers published their method and 56 new gravitational lens candidates in the November issue of Monthly Notices of the Royal Astronomical Society.

    When a galaxy is hidden behind another galaxy, we can sometimes see the hidden one around the front system. This phenomenon is called a gravitational lens, because it emerges from Einstein’s general relativity theory which says that mass can bend light. Astronomers search for gravitational lenses because they help in the research of dark matter.

    The hunt for gravitational lenses is painstaking. Astronomers have to sort thousands of images. They are assisted by enthusiastic volunteers around the world. So far, the search was more or less in line with the availability of new images. But thanks to new observations with special telescopes that reflect large sections of the sky, millions of images are added. Humans cannot keep up with that pace.

    Google, Facebook, Tesla

    To tackle the growing amount of images, the astronomers have used so-called ‘convolutional neural networks’. Google employed such neural networks to win a match of Go against the world champion. Facebook uses them to recognize what is in the images of your timeline. And Tesla has been developing self-driving cars thanks to neural networks.

    The astronomers trained the neural network using millions of homemade images of gravitational lenses. Then they confronted the network with millions of images from a small patch of the sky. That patch had a surface area of 255 square degrees. That’s just over half a percent of the sky.

    Gravitational lens candidates

    Initially, the neural network found 761 gravitational lens candidates. After a visual inspection by the astronomers the sample was downsized to 56. The 56 new lenses still need to be confirmed by telescopes as the Hubble space telescope.

    In addition, the neural network rediscovered two known lenses. Unfortunately, it did not see a third known lens. That is a small lens and the neural network was not trained for that size yet.

    In the future, the researchers want to train their neural network even better so that it notices smaller lenses and rejects false ones. The final goal is to completely remove any visual inspection.

    Kilo-Degree Survey

    Carlo Enrico Petrillo (University of Groningen, The Netherlands), first author of the scientific publication: “This is the first time a convolutional neural network has been used to find peculiar objects in an astronomical survey. I think it will become the norm since future astronomical surveys will produce an enormous quantity of data which will be necessary to inspect. We don’t have enough astronomers to cope with this.”

    The data that the neuronal network processed, came from the Kilo-Degree Survey. The project uses the VLT Survey Telescope of the European Southern Observatory (ESO) on Mount Paranal (Chile). The accompanying panoramic camera, OmegaCAM, was developed under Dutch leadership.


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

    ESO Omegacam on VST at ESO’s Cerro Paranal observatory,with an elevation of 2,635 metres (8,645 ft) above sea level

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

     
  • richardmitnick 4:20 pm on October 9, 2017 Permalink | Reply
    Tags: , , , , Glycolaldehyde and ethylene glycol detected around Sagittarius B2, phys.org, , TMRT   

    From phys.org: “Glycolaldehyde and ethylene glycol detected around Sagittarius B2” 

    physdotorg
    phys.org

    October 9, 2017
    Tomasz Nowakowski

    1
    Color-composite image of the Galactic center and Sagittarius B2 as seen by the ATLASGAL survey. Sagittarius B2 is the bright orange-red region to the middle left of the image, which is centered on the Galactic centre. Credit: ESO/APEX & MSX/IPAC/NASA

    ESO/APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)

    Using the Shanghai Tianma 65m Radio Telescope (TMRT), a team of Chinese astronomers has detected a widespread presence of glycolaldehyde and ethylene glycol around the giant molecular cloud Sagittarius B2. The finding, presented Sept. 29 in a paper published on arXiv.org, could be important for studies of prebiotic molecules in the interstellar medium.

    Sagittarius B2 is a giant molecular cloud of gas and dust with a mass of approximately three million solar masses spanning across 150 light years. It is located some 390 light years from the center of the Milky Way and about 25,000 light years away from the Earth. Its enormous size makes it one of the largest molecular clouds in our galaxy.

    Sagittarius B2 contains various kinds of complex molecules, including alcohols like ethanol and methanol. Previous studies revealed that this cloud exhibits a weak concentration of emission of glycolaldehyde (CH2OHCHO) and ethylene glycol (HOCH2CH2OH). However, the exact extent of this emission remained unclear. Thus, a team of researchers led by Juan Li of the Shanghai Astronomical Observatory, recently conducted new observations of Sagittarius B2 that independently detected the emission of these two molecules, and provided more detailed information about this process.

    The astronomers observed Sagittarius B2 with TMRT in March and November 2016.

    2
    TMRT

    For these observations, they employed the telescope’s digital backend system (DIBAS) with a total bandwidth of 1.2 GHz, and a velocity resolution of 2.0 km/s at a frequency of 13.5 GHz. The team detected widespread glycolaldehyde and ethylene glycol emission, also determining the spatial distribution of these molecules.

    “We report the detection of widespread CH2OHCHO and HOCH2CH2OH emission in galactic center giant molecular cloud Sagittarius B2 using the Shanghai Tianma 65m Radio Telescope,” the researchers wrote in the paper.

    Glycolaldehyde is a sugar-related molecule that can react with propenal to form ribose—a central constituent of RNA. Ethylene glycol is a dialcohol, a molecule chemically related to ethanol. New observations made by Chinese scientists show that the spatial distribution of these two prebiotic molecules around Sagittarius B2 extends over 117 light years. Notably, this extension is about 700 times greater than usually observed in clouds located in the Milky Way’s spiral arms.

    Furthermore, the study revealed that the abundance of glycolaldehyde and ethylene glycol decreases from the cold outer region to the central region of the cloud associated with star formation activity. According to the authors, this suggests that most of the emission is not associated with star formation and that the two studied molecules are likely to form through a low temperature process.

    In concluding remarks, the researchers emphasize the necessity of additional observations of other molecules in order to determine whether some other process are also engaged in the formation of complex organic molecules in the center of the Milky Way. “Future observations of methyl formate are expected to investigate whether energetic processes also play a role in producing complex organic molecules in the Galactic center,” the astronomers concluded.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

     
  • richardmitnick 5:39 am on September 7, 2017 Permalink | Reply
    Tags: , Majorana fermions as the basis for quantum computers, phys.org, Quantum detectives in the hunt for the world's first quantum computer, Station Q Sydney, Topological quantum computers,   

    From U Sidney via phys.org: “Quantum detectives in the hunt for the world’s first quantum computer” 

    U Sidney bloc

    University of Sidney

    phys.org

    September 7, 2017

    2
    Launch of the University of Sydney partnership with Microsoft.Front row: Ph.D. candidate Alice Mahoney with Microsoft’s David Pritchard. Back row (R-L): Station Q Sydney director Professor David Reilly; Microsoft’s Douglas Carmean; Station Q Sydney senior research scientist Dr. Maja Cassidy; University of Sydney Chancellor Belinda Hutchinson, postdoctoral researcher Dr. John Hornibrook and University of Sydney Vice-Chancellor Dr. Michael Spence. Credit: Jayne Ion/University of Sydney

    Scientists at the University of Sydney are entering a new phase of development to scale up the next generation of quantum-engineered devices.

    These devices will form the heart of the first practical topological quantum computers.

    A study released today in Nature Communications confirms one of the prerequisites for building these devices.

    An author of that paper, Dr Maja Cassidy, said: “Here at Station Q Sydney we are building the next generation of devices that will use quasiparticles known as Majorana fermions as the basis for quantum computers.”

    Dr Cassidy said the $150 million Sydney Nanoscience Hub provides a world-class environment in which to build the next generation of devices.

    Microsoft’s Station Q will move scientific equipment into the Nanoscience Hub’s clean rooms – controlled environments with low levels of pollutants and steady temperatures – over the next few months as it increases capacity to develop quantum machines.

    Detective hunt

    Dr Cassidy said that building these quantum devices is a “bit like going on a detective hunt”.

    “When Majorana fermions were first shown to exist in 2012, there were many who said there could be other explanations for the findings,” she said.

    A challenge to show the findings were caused by Majoranas was put to the research team led by Professor Leo Kouwenhoven, who now leads Microsoft’s Station Q in the Netherlands.

    The paper published today meets an essential part of that challenge.

    In essence, it proves that electrons on a one-dimensional semiconducting nanowire will have a quantum spin opposite to its momentum in a finite magnetic field.

    “This information is consistent with previous reports observing Majorana fermions in these nanowires,” Dr Cassidy said.

    She said the findings are not just applicable to quantum computers but will be useful in spintronic systems, where the quantum spin and not the charge is used for information in classical systems.

    Dr Cassidy conducted the research while at the Technical University Delft in the Netherlands, where she held a post-doctorate position. She has since returned to Australia and is based at the University of Sydney Station Q partnership with Microsoft.

    University of Sydney Professor David Reilly is the director of Station Q Sydney.

    “This is practical science at the cutting-edge,” Professor Reilly said. “We have hired Dr Cassidy because her ability to fabricate next-generation quantum devices is second to none.”

    He said Dr Cassidy was one of many great minds attracted to work at Station Q Sydney already this year. “And there are more people joining us soon at Sydney as we build our capacity.”

    Professor Reilly last week won the Australian Financial Review award for Emerging Leadership in Higher Education.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

    U Sidney campus

    Our founding principle as Australia’s first university was that we would be a modern and progressive institution. It’s an ideal we still hold dear today.

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

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

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

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

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

     
  • richardmitnick 1:46 pm on September 6, 2017 Permalink | Reply
    Tags: A scintillating fiber tracker dubbed SciFi, , , , , , , phys.org   

    From EPFL via phys.org: “Particle physicists on a quest for ‘new physics'” 

    EPFL bloc

    École Polytechnique Fédérale de Lausanne EPFL

    phys.org

    Contacts

    Sandy Evangelista Press
    sandy.evangelista@epfl.ch
    +41 79 502 81 06

    Aurelio Bay High Energy Physics Laboratory 1
    aurelio.bay@epfl.ch
    +41 21 693 04 74

    Olivier Schneider High Energy Physics Laboratory 2
    olivier.schneider@epfl.ch
    +41 21 693 05 07

    Tatsuya Nakada High Energy Physics Laboratory 3
    tatsuya.nakada@epfl.ch
    +41 21 693 04 75

    1
    After five years of work, EPFL’s physicists, together with some 800 international researchers involved in the CERN’s LHCb project, have just taken an important step by building a new detector — a scintillating fiber tracker dubbed SciFi — to harvest more data from the collider. Credit: CERN

    3
    Construction of the tracker, which incorporates 10,000 kilometers of scintillating fibers each with a diameter of 0.25mm, has already begun. When particles travel through them, the fibers will give off light signals that will be picked up by light-amplifying diodes. The scintillating fibers will be arranged in three panels measuring five by six meters, installed behind a magnet, where the particles exit the LHC accelerator collision point. The particles will pass through several of these fiber ‘mats’ and deposit part of their energy along the way, producing some photons of light that will then be turned into an electric signal.

    The Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, produces hundreds of millions of proton collisions per second. But researchers working on the Large Hadron Collider beauty (LHCb) experiment, which involves physicists from EPFL, can only record 2,000 of those collisions, using one of the detectors installed on the accelerator. So in the end, this technological marvel leaves the physicists wanting more. They are convinced that the vast volume of uncaptured data holds the answers to several unresolved questions.

    In elementary particle physics, the Standard Model – the theory that best describes phenomena in this field – has been well and truly tried and tested, yet the researchers know that the puzzle is not complete. That’s why they are studying phenomena that are not accounted for by the Standard Model. This quest for “new physics” seeks to explain the disappearance of antimatter after the Big Bang and the nature of the dark matter that, although it represents around 30% of the universe, can only be detected by astronomical measurements at this point.

    “To extract more information from the LHC data, we need new technologies for our LHCb detector,” says Aurelio Bay from EPFL’s Laboratory for High Energy Physics. EPFL has teamed up with several research institutes to develop the new equipment that will upgrade the experiment in 2020.

    Using scintillating fiber to detect particles

    Data on how the particles traverse the fibers will be enough to reconstruct their trajectory. The physicists will then use this information to restore their primitive physical state. “What we will essentially be doing is tracing these particles’ journey back to their starting point. This should give us some insight into what happened 14 billion years ago, before antimatter disappeared, leaving us with the matter we have today,” says Bay.

    Huge data flows

    SciFi is a key component for acquiring data at the highest speed, as it includes filters that are designed to preserve only useful data. In an ideal world, the physicists would collect and analyze all of the data without needing to use too many filters. But that would involve a massive amount of data.

    “We may already be at the limit, because we of course have to save the data somewhere. First we use magnetic storage and then we distribute the data on the LHC GRID, which includes machines in Italy, the Netherlands, Germany, Spain, at CERN, and in France and the UK. Many countries are taking part, and numerous studies on this data are being run simultaneously,” adds Bay. He points to his computer screen: red is used to denote programs that are not working well or those that have been trying for several days to be included among the priorities.

    Bay neatly puts this initiative into a physicist’s perspective: “If the LHC doesn’t have enough power to uncover new physics, it’s all over for my generation of physicists! We will have to come up with a new machine, for the next generation.”

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

    EPFL campus

    EPFL is Europe’s most cosmopolitan technical university with students, professors and staff from over 120 nations. A dynamic environment, open to Switzerland and the world, EPFL is centered on its three missions: teaching, research and technology transfer. EPFL works together with an extensive network of partners including other universities and institutes of technology, developing and emerging countries, secondary schools and colleges, industry and economy, political circles and the general public, to bring about real impact for society.

     
  • richardmitnick 12:13 pm on August 30, 2017 Permalink | Reply
    Tags: , , , , phys.org, Researchers propose how the universe became filled with light, U Iowa   

    From U Iowa via phys.org: “Researchers propose how the universe became filled with light” 

    UI bloc

    University of Iowa

    phys.org

    1
    Credit: CC0 Public Domain

    Soon after the Big Bang, the universe went completely dark. The intense, seminal event that created the cosmos churned up so much hot, thick gas that light was completely trapped. Much later—perhaps as many as one billion years after the Big Bang—the universe expanded, became more transparent, and eventually filled up with galaxies, planets, stars, and other objects that give off visible light. That’s the universe we know today.

    How it emerged from the cosmic dark ages to a clearer, light-filled state remains a mystery.

    In a new study [MNRAS], researchers at the University of Iowa offer a theory of how that happened. They think black holes that dwell in the center of galaxies fling out matter so violently that the ejected material pierces its cloudy surroundings, allowing light to escape. The researchers arrived at their theory after observing a nearby galaxy from which ultraviolet light is escaping.

    “The observations show the presence of very bright X-ray sources that are likely accreting black holes,” says Philip Kaaret, professor in the UI Department of Physics and Astronomy and corresponding author on the study. “It’s possible the black hole is creating winds that help the ionizing radiation from the stars escape. Thus, black holes may have helped make the universe transparent.”

    Kaaret and his team focused on a galaxy called Tol 1247-232, located some 600 million light years from Earth, one of only three nearby galaxies from which ultraviolet light has been found to escape. In May 2016, using an Earth-orbiting telescope called Chandra, the researchers saw a single X-ray source whose brightness waxed and waned and was located within a vigorous star-forming region of Tol 1247-232.

    The team determined it was something other than a star.

    “Stars don’t have changes in brightness,” Kaaret says. “Our sun is a good example of that.

    “To change in brightness, you have to be a small object, and that really narrows it down to a black hole,” he says.

    But how would a black hole, whose intense gravitational pull sucks in everything around it, also eject matter?

    The quick answer is no one knows for sure. Black holes, after all, are hard to study, in part because their immense gravitational pull allows no light to escape and because they’re embedded deep within galaxies. Recently, however, astronomers have offered an explanation: The jets of escaping matter are tapping into the accelerated rotational energy of the black hole itself.

    Imagine a figure skater twirling with outstretched arms. As the skater folds her arms closer to her body, she spins faster. Black holes operate much the same way: As gravity pulls matter inward toward a black hole, the black hole likewise spins faster. As the black hole’s gravitational pull increases, the speed also creates energy.

    “As matter falls into a black hole, it starts to spin and the rapid rotation pushes some fraction of the matter out,” Kaaret says. “They’re producing these strong winds that could be opening an escape route for ultraviolet light. That could be what happened with the early galaxies.”

    Kaaret plans to study Tol 1247-232 more closely and find other nearby galaxies that are leaking ultraviolet light, which would help corroborate his theory.

    See the full article here .

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    UI campus

    UI is a flagship public research university in Iowa City, Iowa. Founded in 1847, Iowa is the oldest university in the state. The University of Iowa is organized into eleven colleges offering more than 200 areas of study and seven professional degrees.

    The Iowa campus spans 1,700 acres centered along the banks of the Iowa River and includes the University of Iowa Hospitals and Clinics, named one of “America’s Best Hospitals” for the 25th year in a row. The university was the original developer of the Master of Fine Arts degree and it operates the world-renowned Iowa Writers’ Workshop. Iowa has very high research activity, and is a member of several research coalitions, including the prestigious Association of American Universities, the Universities Research Association, and the Committee on Institutional Cooperation.

    The University of Iowa was founded on February 25, 1847, just 59 days after Iowa was admitted to the Union. The Constitution of the State of Iowa refers to a State University to be established in Iowa City “without branches at any other place.” The legal name of the university is the State University of Iowa, but the Board of Regents approved using the “University of Iowa” for everyday usage in October 1964.

    The first faculty offered instruction at the university beginning in March 1855 to students in the Old Mechanics Building, located where Seashore Hall is now. In September 1855, there were 124 students, of whom forty-one were women. The 1856–57 catalogue listed nine departments offering ancient languages, modern languages, intellectual philosophy, moral philosophy, history, natural history, mathematics, natural philosophy, and chemistry.

     
  • richardmitnick 4:50 pm on July 11, 2017 Permalink | Reply
    Tags: 800 million years is the current frontier in reionization studies, , , , , , , Determining when the first galaxies formed is a challenge, LAEs-Lyman alpha emitting galaxies, phys.org   

    From phys.org: “Distant galaxies ‘lift the veil’ on the end of the cosmic dark ages” 

    physdotorg
    phys.org

    July 11, 2017

    1
    False color image of a 2 square degree region of the LAGER survey field, created from images taken in the optical at 500 nm (blue), in the near-infrared at 920 nm (red), and in a narrow-band filter centered at 964 nm (green). The last is sensitive to hydrogen Lyman alpha emission at z ~ 7. The small white boxes indicate the positions of the 23 LAEs discovered in the survey. The detailed insets (yellow) show two of the brightest LAEs; they are 0.5 arcminutes on a side, and the white circles are 5 arcseconds in diameter. Credit: Zhen-Ya Zheng (SHAO) & Junxian Wang (USTC).

    Astronomers studying the distant Universe have found that small star-forming galaxies were abundant when the Universe was only 800 million years old, a few percent of its present age. The results suggest that the earliest galaxies, which illuminated and ionized the Universe, formed at even earlier times.

    Long ago, about 300,000 years after the beginning of the Universe (the Big Bang), the Universe was dark. There were as yet no stars and galaxies, and the Universe was filled with neutral hydrogen gas. At some point the first galaxies appeared, and their energetic radiation ionized their surroundings, the intergalactic gas, illuminating and transforming the Universe.

    While this dramatic transformation is known to have occurred sometime in the interval between 300 million years and 1 billion years after the Big Bang, determining when the first galaxies formed is a challenge. The intergalactic gas, which is initially neutral, strongly absorbs and scatters the ultraviolet light emitted by the galaxies, making them difficult to detect.

    To home in on when the transformation occurred, astronomers take an indirect approach. Using the demographics of small star-forming galaxies to determine when the intergalactic gas became ionized, they can infer when the ionizing sources, the first galaxies, formed. If star forming galaxies, which glow in the light of the hydrogen Lyman alpha line, are surrounded by neutral hydrogen gas, the Lyman alpha photons are readily scattered, much like headlights in fog, obscuring the galaxies. When the gas is ionized, the fog lifts, and the galaxies are easier to detect.

    A new study [ApJ] taking this approach has discovered 23 candidate Lyman alpha emitting galaxies (LAEs) that were present 800 million years after the Big Bang (at a redshift of z~7), the largest sample detected to date at that epoch. The study, “Lyman-Alpha Galaxies in the Epoch of Reionization” (LAGER), was carried out by an international team of astronomers from China, the US, and Chile using the Dark Energy Camera (DECam) on the CTIO 4-m Blanco telescope.

    Dark Energy Survey

    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam

    2
    Milestones in the history of the Universe (not to scale). The intergalactic gas was in a neutral state from about 300,000 years after the Big Bang until light from the first generation of stars and galaxies began to ionize it. The gas was completely ionized after 1 billion years. The LAGER study takes a close look at the state of the Universe at 800 million years (yellow box) to investigate when and how this transformation occurred. Credit: NAOJ.

    While the study detected many LAEs, it also found that LAEs were 4 times less common at 800 million years than they were a short time later, at 1 billion years (at a redshift of z~5.7). The results imply that the process of ionizing the Universe began early and was still incomplete at 800 million years, with the intergalactic gas about half neutral and half ionized at that epoch. The low incidence rate of LAEs at 800 million years results from the suppression of their Lyman alpha emission by neutral intergalactic gas.

    The study shows that “the fog was already lifting when the universe was 5% of its current age”, explained Sangeeta Malhotra (Goddard Space Flight Center and Arizona State University), one of the co-leads of the survey.

    Junxian Wang (USTC), the organizer of the study, further explained, “Our finding that the intergalactic gas is 50% ionized at z ~ 7 implies that a large fraction of the first galaxies that ionized and illuminated the universe formed early, less than 800 million years after the Big Bang.”

    For Zhenya Zheng (Shanghai Astronomical Observatory, CAS), the lead author of the paper describing these results, “800 million years is the current frontier in reionization studies.” While hundreds of LAEs have been found at later epochs, only about two dozen candidate LAEs were known at 800 million years prior to the current study. The new results dramatically increase the number of LAEs known at this epoch.

    “None of this science would have been possible without the widefield capabilities of DECam and its community pipeline for data reduction,” remarked coauthor James Rhoads. “These capabilities enable efficient surveys and thereby the discovery of faint galaxies as well as rare, bright ones.”

    To build on these results, the team is “continuing the search for distant star forming galaxies over a larger volume of the Universe”, said Leopoldo Infante (Pontificia Catolica University of Chile and the Carnegie Institution for Science), “to study the clustering of LAEs.” Clustering provides unique insights into how the fog lifts. The team is also investigating the nature of these distant galaxies.

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

     
  • richardmitnick 2:48 pm on July 10, 2017 Permalink | Reply
    Tags: , , , How do you build a metal nanoparticle?, phys.org, , U Pittsburgh   

    From U Pittsburgh via phys.org: “How do you build a metal nanoparticle?” 

    University of Pittsburgh

    phys.org

    July 10, 2017

    1
    A structure of a ligand-protected Au25 nanocluster. Credit: Computer-Aided Nano and Energy Lab (C.A.N.E.LA.)

    Although scientists have for decades been able to synthesize nanoparticles in the lab, the process is mostly trial and error, and how the formation actually takes place is obscure. However, a study recently published in Nature Communications by chemical engineers at the University of Pittsburgh’s Swanson School of Engineering explains how metal nanoparticles form.

    Thermodynamic Stability of Ligand-Protected Metal Nanoclusters (DOI: 10.1038/ncomms15988) was co-authored by Giannis Mpourmpakis, assistant professor of chemical and petroleum engineering, and PhD candidate Michael G. Taylor. The research, completed in Mpourmpakis’ Computer-Aided Nano and Energy Lab (C.A.N.E.LA.), is funded through a National Science Foundation CAREER award and bridges previous research focused on designing nanoparticles for catalytic applications.

    “Even though there is extensive research into metal nanoparticle synthesis, there really isn’t a rational explanation why a nanoparticle is formed,” Dr. Mpourmpakis said. “We wanted to investigate not just the catalytic applications of nanoparticles, but to make a step further and understand nanoparticle stability and formation. This new thermodynamic stability theory explains why ligand-protected metal nanoclusters are stabilized at specific sizes.”

    A ligand is a molecule that binds to metal atoms to form metal cores that are stabilized by a shell of ligands, and so understanding how they contribute to nanoparticle stabilization is essential to any process of nanoparticle application. Dr. Mpourmpakis explained that previous theories describing why nanoclusters stabilized at specific sizes were based on empirical electron counting rules – the number of electrons that form a closed shell electronic structure, but show limitations since there have been metal nanoclusters experimentally synthesized that do not necessarily follow these rules.

    “The novelty of our contribution is that we revealed that for experimentally synthesizable nanoclusters there has to be a fine balance between the average bond strength of the nanocluster’s metal core, and the binding strength of the ligands to the metal core,” he said. “We could then relate this to the structural and compositional characteristic of the nanoclusters, like size, number of metal atoms, and number of ligands.

    “Now that we have a more complete understanding of this stability, we can better tailor the nanoparticle morphologies and in turn properties, to applications from biolabeling of individual cells and targeted drug delivery to catalytic reactions, thereby creating more efficient and sustainable production processes.”

    See the full article here. .

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    The University of Pittsburgh is a state-related research university, founded as the Pittsburgh Academy in 1787. Pitt is a member of the Association of American Universities (AAU), which comprises 62 preeminent doctorate-granting research institutions in North America.

    From research achievements to the quality of its academic programs, the University of Pittsburgh ranks among the best in higher education.

    Faculty members have expanded knowledge in the humanities and sciences, earning such prestigious honors as the National Medal of Science, the MacArthur Foundation’s “genius” grant, the Lasker-DeBakey Clinical Medical Research Award, and election to the National Academy of Sciences and the Institute of Medicine.

    Pitt students have earned Rhodes, Goldwater, Marshall, and Truman Scholarships, among other highly competitive national and international scholarships.

    Alumni have pioneered MRI and TV, won Nobels and Pulitzers, led corporations and universities, served in government and the military, conquered Hollywood and The New York Times bestsellers list, and won Super Bowls and NBA championships.

     
  • richardmitnick 2:58 pm on July 4, 2017 Permalink | Reply
    Tags: , , , , e-MERLIN radio array, NGC 5194 and NGC 5195, phys.org   

    From phys.org: “Shocking case of indigestion in supermassive black hole July 4, 2017” 

    physdotorg
    phys.org

    July 4, 2017
    No writer credit found

    1
    False colour image of NGC 5195 created by combining the VLA 20 cm radio image (red), the Chandra X-ray image (green), and the Hubble Space telescope H-alpha image (blue). The image shows the X-ray and H-alpha arcs, as well as the radio outflows from the supermassive black hole at the centre of NGC 5195. Credit: NRAO / AUI / NSF / NASA / CXC / NASA / ESA / STScI / U. Manchester / Rampadarath et al.

    A multi-wavelength study of a pair of colliding galaxies has revealed the cause of a supermassive black hole’s case of ‘indigestion.’ Results will be presented by Dr Hayden Rampadarath at the National Astronomy Meeting at the University of Hull.

    Once every couple of hundred million years, the small galaxy NGC 5195 falls into the outer arms of its larger companion, NGC 5194, also known as the Whirlpool galaxy. Both galaxies are locked in a gravitational dance that will result – billions of years in the future – in the formation of a single galaxy.

    As NGC 5195 plunges into the Whirlpool, matter streams onto the supermassive black hole at NGC 5195’s centre and forms an accretion disc. The disc grows to a point where the supermassive black hole can no longer accrete or ‘digest’ efficiently and matter is blasted out into the surrounding interstellar medium. Last year, NASA’s Chandra X-Ray observatory spotted arcs of X-ray emission that appeared to result from this ‘force-feeding.’

    NASA/Chandra Telescope

    Now, new high-resolution images of the core of NGC 5195, taken with the e-MERLIN radio array, and archive images of the surrounding area from the Very Large Array (VLA), Chandra and the Hubble Space Telescope, reveal in detail how these blasts occur and spread. The study was led by astronomers at the University of Manchester’s Jodrell Bank Centre for Astrophysics.

    eMerlin Radio Telecope Array, England

    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    NASA/ESA Hubble Telescope

    3
    e-MERLIN maps of the nuclear region of NGC 5195 at 1.4 GHz (left) and 5 GHz (right). The images display a partially resolved source with possible parsec-scale outflows. Credit: e-MERLIN / U. Manchester / Rampadarath et al.

    The supermassive black hole at the centre of NGC 5195 has a mass equivalent to 19 million Suns. When the accretion process breaks down, immense forces and pressures create a shock wave that pushes matter out into the interstellar medium. Electrons, accelerated close to the speed of light, interact with the magnetic field of the interstellar medium and emit energy at radio wavelengths. The shock wave then inflates and heats up the interstellar medium, which emits in the X-ray, and strips the electrons from surrounding neutral hydrogen atoms to make ionised hydrogen gas. This inflated bubble creates the arcs detected by Chandra and Hubble.

    Rampadarath explains: “Comparing the VLA images at radio wavelengths to Chandra’s X-ray observations and the hydrogen-emission detected by Hubble, shows that features are not only connected, but that the radio outflows are in fact the progenitors of the structures seen by Chandra and Hubble. This is an event of galactic proportions that we can see right across the electromagnetic spectrum.”

    He adds: “The age of the arcs in NGC 5195 is 1-2 million years. To put that into context, the first traces of matter were being forced out of the black hole in this system at about the time that our ancestors were learning to make fire. That we are able to observe this event now through such a range of astronomical facilities is quite remarkable.”

    See the full article here .

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) 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, Phys.org’s readership has grown steadily to include 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.

     
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