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  • richardmitnick 2:01 pm on April 4, 2019 Permalink | Reply
    Tags: , , Caltech, The mathematical universe, , Yeorgia Kafkoulis   

    From Caltech: Women in STEM -“A Mathematical Universe” Yeorgia Kafkoulis 

    Caltech Logo

    From Caltech

    4.4.19

    1

    Even our most reliable ideas about how the universe works break down in certain domains. They can’t account for the weirdness of quantum mechanics or the recursive chaos of fractals. Hungry for answers, many researchers—including one Caltech undergraduate and her faculty mentor—aim to come up with a better explanation.

    Contributing to a grand unified theory ought to be a daunting task. But true to the Caltech spirit, mathematics scholar Yeorgia Kafkoulis thrills at the challenge.

    “The fact that there are so many open questions means that there’s more to explore, more to learn about, and more to question,” says Kafkoulis, a member of the class of 2019.

    Each summer, she joins up with the research team led by Caltech mathematics professor Matilde Marcolli. Kafkoulis’s task is part of an ambitious project: exploring the Swiss-cheese model of cosmology, a recalculation of the fundamental laws of nature.

    Just as a Gantvoort Scholarship has helped underwrite her classroom education, her opportunities as a burgeoning investigator come courtesy of donor funding, in the form of the Summer Undergraduate Research Fellowships (SURF) program.

    ___________________________________________________

    “I came to Caltech to learn, but I also came to do research. SURF has opened my eyes to this world of mathematical physics in particular, and also to research in general. It’s a little sneak peek into my future.”

    • Yeorgia Kafkoulis

    __________________________________________________

    Big Cheese

    As Marcolli, Kafkoulis, and colleagues seek to reconcile Einstein’s general relativity with more exotic phenomena, they double-down by questioning Newton’s assumptions.

    His cosmological principle depended upon two things. One, that the rules of physics work the same way anywhere in the universe. Two, that on a large scale, the distribution of matter is about the same everywhere.

    The Swiss-cheese model presents a concept of gravity that removes one of those assumptions. What if matter is not evenly distributed in the universe?

    In this model, you might expect to see a cosmos made of denser stretches and pockets of emptiness—not unlike that holey Alpine cheese. You also might see the beginnings of explanations for the quantum strangeness and fractal chaos that defy the models of Einstein and Newton.

    Marcolli’s team tries out new ideas in this framework and examines the effects of a modified gravity model as the universe expands over time. Elaborating on the notion of a block of cheese, this conception describes spacetime as shaped like a many-dimensioned set of bubbles.

    Kafkoulis is looking for patterns in how those bubbles pack together. The arrangement seems to resemble swirling multifractals.

    “Fractal-like behavior isn’t explained by the standard model,” Kafkoulis explains. “At times, the universe behaves like a fractal—in supernovae, in clusters of stars and galaxies, even in the composition of stars. To describe the universe accurately, you need to explain that fracticality.”

    Awe, Excitement, and Pizza

    Kafkoulis connected with her mentor early, in the first term of her freshman year. The setting was Math 20, a seminar that serves up lectures from different professors and pizza for lunch. Marcolli’s “pizza course” presentation made a big impression.

    “I heard ‘Swiss-cheese model of cosmology,’ and my spider-sense started tingling,” Kafkoulis says. “As I started to get a sense for what Professor Marcolli was talking about, I was like, ‘This is awesome!’ And I mean that in the strict sense of the word. ‘This inspires awe.’”

    By the next week, Kafkoulis was leaving Marcolli’s office with reading materials in hand and a newly forged SURF match that would enrich her Caltech career.

    In the summers, Kafkoulis diligently proves theorems, reads countless papers, and meets with Marcolli each week to compare notes, both one-on-one and as part of her team. Her mentor’s enthusiasm for exploring Kafkoulis’s ideas has stoked her confidence.

    “Professor Marcolli has helped me become a better mathematician and a better scientist,” Kafkoulis says. “She inspires me to jump forward in whatever I’m doing—just dive headfirst into the deep waters. She is, I tell people, what I want to be when I grow up.”

    A Lifelong Fascination

    Kafkoulis remembers her passion for understanding the universe first igniting when she was 5 years old. A public television series about string theory held her transfixed.

    “I would run to my parents and explain what I had seen—even though I didn’t really understand it,” she laughs.

    Academics themselves, her parents encouraged her love of science. And her father, a Caltech PhD, had one suggestion in particular for her future path, leading her far from their home in Miami.

    “What he said made Caltech seem like this utopia, even when I was 5,” she says. “He described it as welcoming and intellectually stimulating. He kept saying: ‘Caltech is not the only place. But it might make a pretty good place for you.’”

    Her eagerness to take on the biggest kinds of research questions suggests that the elder Kafkoulis might have been onto something.

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 12:52 pm on March 7, 2019 Permalink | Reply
    Tags: Caltech, Kip Thorne   

    From Caltech: “VIDEO: Kip Thorne’s Watson Lecture” 

    Caltech Logo

    From Caltech

    1
    VIDEO: Kip Thorne’s Watson Lecture


    1:15

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 3:56 pm on March 5, 2019 Permalink | Reply
    Tags: Caltech, , Earthquake hazards, Geophysicists at Caltech have created a new method for determining earthquake hazards by measuring how fast energy is building up on faults in a specific region and then comparing that to how much is , , , , The method also allows for an assessment of the likelihood of smaller earthquakes. If one excludes aftershocks the probability that a magnitude 6.0 or greater earthquake will occur in central LA over , They applied the new method to the faults underneath central Los Angeles and found that on the long-term average the strongest earthquake that is likely to occur along those faults is between magnitud, They find that the crust beneath Los Angeles does not seem to be being squeezed from south to north fast enough to make such an earthquake quite as likely, When one tectonic plate pushes against another elastic strain is built up along the boundary between the two plates. The strain increases until one plate either creeps slowly past the other or it jerk   

    From Caltech: “Fast, Simple New Assessment of Earthquake Hazard” 

    Caltech Logo

    From Caltech

    1
    Credit: Juan Vargas, Jean-Philippe Avouac, Chris Rollins / Caltech

    March 04, 2019

    Contact
    Robert Perkins
    (626) 395‑1862
    rperkins@caltech.edu

    Geophysicists at Caltech have created a new method for determining earthquake hazards by measuring how fast energy is building up on faults in a specific region, and then comparing that to how much is being released through fault creep and earthquakes.

    They applied the new method to the faults underneath central Los Angeles, and found that on the long-term average, the strongest earthquake that is likely to occur along those faults is between magnitude 6.8 and 7.1, and that a magnitude 6.8—about 50 percent stronger than the 1994 Northridge earthquake—could occur roughly every 300 years on average.

    That is not to say that a larger earthquake beneath central L.A. is impossible, the researchers say; rather, they find that the crust beneath Los Angeles does not seem to be being squeezed from south to north fast enough to make such an earthquake quite as likely.

    The method also allows for an assessment of the likelihood of smaller earthquakes. If one excludes aftershocks, the probability that a magnitude 6.0 or greater earthquake will occur in central LA over any given 10-year period is about 9 percent, while the chance of a magnitude 6.5 or greater earthquake is about 2 percent.

    A paper describing these findings was published by Geophysical Research Letters on February 27.

    These levels of seismic hazard are somewhat lower but do not differ significantly from what has already been predicted by the Working Group on California Earthquake Probabilities. But that is actually the point, the Caltech scientists say.

    Current state-of-the-art methods for assessing the seismic hazard of an area involve generating a detailed assessment of the kinds of earthquake ruptures that can be expected along each fault, a complicated process that relies on supercomputers to generate a final model. By contrast, the new method—developed by Caltech graduate student Chris Rollins and Jean-Philippe Avouac, Earle C. Anthony Professor of Geology and Mechanical and Civil Engineering—is much simpler, relying on the strain budget and the overall earthquake statistics in a region.

    “We basically ask, ‘Given that central L.A. is being squeezed from north to south at a few millimeters per year, what can we say about how often earthquakes of various magnitudes might occur in the area, and how large earthquakes might get?'” Rollins says.

    When one tectonic plate pushes against another, elastic strain is built up along the boundary between the two plates. The strain increases until one plate either creeps slowly past the other, or it jerks violently. The violent jerks are felt as earthquakes.

    Fortunately, the gradual bending of the crust between earthquakes can be measured at the surface by studying how the earth’s surface deforms. In a previous study [JGR Solid Earth] (done in collaboration with Caltech research software engineer Walter Landry; Don Argus of the Jet Propulsion Laboratory, which is managed by Caltech for NASA; and Sylvain Barbot of USC), Avouac and Rollins measured ground displacement using permanent global positioning system (GPS) stations that are part of the Plate Boundary Observatory network, supported by the National Science Foundation (NSF) and NASA. The GPS measurements revealed how fast the land beneath L.A. is being bent. From that, the researchers calculated how much strain was being released by creep and how much was being stored as elastic strain available to drive earthquakes.

    This research was supported by a NASA Earth and Space Science Fellowship.

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 9:48 am on February 28, 2019 Permalink | Reply
    Tags: "More Support for Planet Nine", , , , Caltech, , Mike Brown and Konstantin Batygin   

    From Caltech and U Michigan: “More Support for Planet Nine” 

    U Michigan bloc

    University of Michigan

    Caltech Logo

    From Caltech

    February 27, 2019
    Robert Perkins
    (626) 395‑1862
    rperkins@caltech.edu

    1
    Credit: James Tuttle Keane/Caltech

    2
    This illustration depicts orbits of distant Kuiper Belt objects and Planet Nine. Orbits rendered in purple are primarily controlled by Planet Nine’s gravity and exhibit tight orbital clustering. Green orbits, on the other hand, are strongly coupled to Neptune, and exhibit a broader orbital dispersion. Credit: James Tuttle Keane/Caltech

    Three years after hypothesizing its existence, the researchers behind the theory present further arguments in favor of a ninth planet in the solar system.

    Corresponding with the three-year anniversary of their announcement hypothesizing the existence of a ninth planet in the solar system, Caltech’s Mike Brown and Konstantin Batygin are publishing a pair of papers analyzing the evidence for Planet Nine’s existence.

    The papers offer new details about the suspected nature and location of the planet, which has been the subject of an intense international search ever since Batygin and Brown’s 2016 announcement.

    The first, titled “Orbital Clustering in the Distant Solar System,” was published in The Astronomical Journal on January 22. The Planet Nine hypothesis is founded on evidence suggesting that the clustering of objects in the Kuiper Belt, a field of icy bodies that lies beyond Neptune, is influenced by the gravitational tugs of an unseen planet.It has been an open question as to whether that clustering is indeed occurring, or whether it is an artifact resulting from bias in how and where Kuiper Belt objects are observed.

    Kuiper Belt. Minor Planet Center

    To assess whether observational bias is behind the apparent clustering, Brown and Batygin developed a method to quantify the amount of bias in each individual observation, then calculated the probability that the clustering is spurious. That probability, they found, is around one in 500.

    “Though this analysis does not say anything directly about whether Planet Nine is there, it does indicate that the hypothesis rests upon a solid foundation,” says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy.

    The second paper is titled “The Planet Nine Hypothesis,” and is an invited review that will be published in the next issue of Physics Reports. The paper provides thousands of new computer models of the dynamical evolution of the distant solar system and offers updated insight into the nature of Planet Nine, including an estimate that it is smaller and closer to the sun than previously suspected. Based on the new models, Batygin and Brown—together with Fred Adams and Juliette Becker (BS ’14) of the University of Michigan—concluded that Planet Nine has a mass of about five times that of the earth and has an orbital semimajor axis in the neighborhood of 400 astronomical units (AU), making it smaller and closer to the sun than previously suspected—and potentially brighter. Each astronomical unit is equivalent to the distance between the center of Earth and the center of the sun, or about 149.6 million kilometers.

    “At five Earth masses, Planet Nine is likely to be very reminiscent of a typical extrasolar super-Earth,” says Batygin, an assistant professor of planetary science and Van Nuys Page Scholar. Super-Earths are planets with a mass greater than Earth’s, but substantially less than that of a gas giant. “It is the solar system’s missing link of planet formation. Over the last decade, surveys of extrasolar planets have revealed that similar-sized planets are very common around other sun-like stars. Planet Nine is going to be the closest thing we will find to a window into the properties of a typical planet of our galaxy.”

    Batygin and Brown presented the first evidence that there might be a giant planet tracing a bizarre, highly elongated orbit through the outer solar system on January 20, 2016. That June, Brown and Batygin followed up with more details, including observational constraints [The Astrophysical Journal] on the planet’s location along its orbit.

    Over the next two years, they developed theoretical models of the planet that explained other known phenomena, such as why some Kuiper Belt objects have a perpendicular orbit [The Astrophysical Journal] with respect to the plane of the solar system. The resulting models increased their confidence in Planet Nine’s existence.

    After the initial announcement, astronomers around the world, including Brown and Batygin, began searching for observational evidence of the new planet. Although Brown and Batygin have always accepted the possibility that Planet Nine might not exist, they say that the more they examine the orbital dynamics of the solar system, the stronger the evidence supporting it seems.

    “My favorite characteristic of the Planet Nine hypothesis is that it is observationally testable,” Batygin says. “The prospect of one day seeing real images of Planet Nine is absolutely electrifying. Although finding Planet Nine astronomically is a great challenge, I’m very optimistic that we will image it within the next decade.”

    The work was supported by the David and Lucile Packard Foundation and the Alfred P. Sloan Foundation.

    See the full Caltech article here .

    See the full U Michigan article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 9:08 pm on February 15, 2019 Permalink | Reply
    Tags: Caltech, , LIGO Receives New Funding to Search for More Extreme Cosmic Events   

    From Caltech: “LIGO Receives New Funding to Search for More Extreme Cosmic Events” 

    Caltech Logo

    From Caltech

    02/14/2019

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Engineers installing Advanced LIGO upgrades.
    Credit: Caltech/MIT/LIGO Lab

    Grants from the U.S., United Kingdom, and Australia will fund next-generation improvements to LIGO.

    The National Science Foundation (NSF) is awarding Caltech and MIT $20.4 million to upgrade the Laser Interferometer Gravitational-wave Observatory (LIGO), an NSF-funded project that made history in 2015 after making the first direct detection of ripples in space and time, called gravitational waves.


    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project


    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    ESA/eLISA the future of gravitational wave research

    The investment is part of a joint international effort in collaboration with UK Research and Innovation and the Australian Research Council, which are contributing additional funds. While LIGO is scheduled to turn back on this spring, in its third run of the “Advanced LIGO” phase, the new funding will go toward “Advanced LIGO Plus.” Advanced LIGO Plus is expected to commence operations in 2024 and to increase the volume of deep space the observatory can survey by as much as seven times.

    “I’m extremely excited about the future prospects that the Advanced LIGO Plus upgrade affords gravitational-wave astrophysics,” said Caltech’s David Reitze, executive director of LIGO. “With it we expect to detect gravitational waves from black hole mergers on a daily basis, greatly increasing our understanding of this dark sector of the universe. Gravitational-wave observations of neutron star collisions, now very rare, will become much more frequent, allowing us to more deeply probe the structure of their exotic interiors.”

    Since LIGO’s first detection of gravitational waves from the violent collision of two black holes, it has observed nine additional black hole mergers and one collision of two dense, dead stars called neutron stars. The neutron star merger gave off not just gravitational waves but light waves, detected by dozens of telescopes in space and on the ground. The observations confirmed that heavy elements in our universe, such as platinum and gold, are created in neutron star smashups like this one.

    “This award ensures that NSF’s LIGO, which made the first historic detection of gravitational waves in 2015, will continue to lead in gravitational-wave science for the next decade,” said Anne Kinney, assistant director for NSF’s Mathematical and Physical Sciences Directorate, in a statement. “With improvements to the detectors—which include techniques from quantum mechanics that refine laser light and new mirror coating technology—the twin LIGO observatories will significantly increase the number and strength of their detections. Advanced LIGO Plus will reveal gravity at its strongest and matter at its densest in some of the most extreme environments in the cosmos. These detections may reveal secrets from inside supernovae and teach us about extreme physics from the first seconds after the universe’s birth.”

    Michael Zucker, the Advanced LIGO Plus leader and co-principal investigator, and a scientist at the LIGO Laboratory, operated by Caltech and MIT, said, “I’m thrilled that NSF, UK Research, and Innovation and the Australian Research Council are joining forces to make this key investment possible. Advanced LIGO has altered the course of astrophysics with 11 confirmed gravitational-wave events over the last three years. Advanced LIGO Plus can expand LIGO’s horizons enough to capture this many events each week, and it will enable powerful new probes of extreme nuclear matter as well as Albert Einstein’s general theory of relativity.”

    LIGO is funded by NSF and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF, with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council), and Australia (Australian Research Council-OzGrav) making significant commitments and contributions to the project.

    More than 1,200 scientists from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration. A list of additional partners is available at https://my.ligo.org/census.php. LIGO partners with the European Virgo gravitational-wave detector and its collaboration, consisting of more than 300 physicists and engineers belonging to 28 different European research groups.

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 12:58 pm on January 31, 2019 Permalink | Reply
    Tags: A new test for understanding the specific difficulties faced by people with autism, , Autism and Theory of Mind, Autism is not one thing, Caltech   

    From Caltech: “Autism and Theory of Mind” 

    Caltech Logo

    From Caltech

    01/24/2019

    Emily Velasco
    626-395-6487
    evelasco@caltech.edu

    1
    Credit: iStock

    A new test for understanding the specific difficulties faced by people with autism.

    Suppose you are helping your friend search for their missing phone and while they are looking around another room, you find it behind some cushions. When they return, you seize the opportunity to play a prank on them and pretend the phone is still missing. You are able to envision this prank because you know that their understanding of the world is separate from what you know to be true. This is an example of theory of mind: the ability to understand other people’s beliefs, preferences, and intentions as distinct from one’s own.

    Theory of mind is complex and involves multiple neural processes. A team of researchers has now developed a new test to examine these components and has found that people with autism—a group known to have trouble understanding the thoughts, plans, and point of view of others—have disproportionate difficulties in one particular process. The work may lead to a better understanding of autism itself.

    A paper describing the work appears in the February 4 issue of the journal Current Biology. The study was designed by Damian Stanley (senior and corresponding author), an assistant professor at Adelphi University and visiting associate in psychology at Caltech. The work was conducted in the laboratory of Ralph Adolphs (PhD ’93), Bren Professor of Psychology, Neuroscience, and Biology; and director and Allen V. C. Davis and Lenabelle Davis Leadership Chair of the Caltech Brain Imaging Center, a center of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech. Graduate student Isabelle Rosenthal is the paper’s first author and Cendri Hutcherson, a faculty member at the University of Toronto at Scarborough, is a co-author.

    “Autism is not one thing,” says Adolphs. “Our task allows researchers to quantitatively deconstruct the components of theory of mind, to see where different people have trouble, and this may reveal to us subtypes of autism.”

    A classic test of theory of mind, often demonstrated in children, involves a closed box of Band-Aids. When asked what is in the box, a child will respond, “Band-Aids.” The box is then opened to reveal that it contains crayons, not Band-Aids. The child is then asked, “If someone else were to come in and see the closed box, what would they think is inside?”

    Children under age 4 will often answer, “crayons,” because they have not yet developed theory of mind. In other words, the child will assume that others will know what the child knows—that the box contains crayons, not Band-Aids. Older children who have theory of mind will reason that another person would see the box’s exterior and wrongly conclude, as they did, that it contains Band-Aids.

    This test is broad and easy. Nearly all high-functioning adults with autism (the population studied by Adolphs and Stanley) have no difficulty passing it, but that unfortunately means that the test reveals little about the constituent processes required for theory of mind and specific points of impairment in individuals taking the test.

    The new test developed by Adolphs and Stanley’s team is much more complex. In the new test, a participant learns about a person who is playing a particular game. The player—let’s call her Sally—has some money and must decide whether to donate it to one of three charities or keep it for herself. Sally has some preferences about which charities she likes and which she does not. She is also switching back and forth between two “environments,” a “reversal” environment in which her actions mostly have the opposite effect (i.e., donating money actually means she gets to keep it), and a “normal” environment, where things mostly go as expected. Sally does not know for sure which environment she is in, so she has to keep track of what happens to her decisions and take this into account when deciding about donating her money.

    The individual actually taking the test watches what Sally does and must learn from her decisions to make inferences about her beliefs and preferences in order to predict her future actions. Does Sally believe she is in a normal or a reversal world? Which charities does she like? Which does she dislike? What will she do?

    While this task is complex and difficult, adults with and without autism can understand it once it has been thoroughly explained and practiced. However, people with autism who took the test failed at one particular part: they could track Sally’s beliefs about the environment and make logical conclusions about her behavior, but they could not learn which charities Sally intended to donate to and when she would keep the money for herself.

    “This task gives us the ability to deconstruct these different components of theory of mind and see that it’s not basic learning or the logical reasoning component that’s impaired in people with autism. What seems to break down is actually the specific ability to take into account someone’s beliefs when you’re interpreting their actions,” says Stanley. “This more detailed understanding of how theory of mind can be impaired, in turn, gives us more purchase on how we could develop treatments in the future.”

    “This test is very valuable because in reality people learn over time about others’ changing beliefs from watching what they do,” says Rosenthal. “So the task, although complex, in fact tries to approximate what happens in the real world—which is, after all, what we’re ultimately interested in explaining.”

    Funding was provided by the National Institute of Mental Health of the National Institutes of Health.

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 1:31 pm on January 24, 2019 Permalink | Reply
    Tags: "When Black Holes Collide", , , , , Caltech, ,   

    From Caltech: “When Black Holes Collide” 

    Caltech Logo

    From Caltech

    01/24/2019

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    A simulated picture of two merging black holes, each about 30 solar masses. This is approximately what a human would see if they could travel in spaceship to take a closer look at merging black holes.
    Credit: SXS, the Simulating eXtreme Spacetimes (SXS) project (http://www.black-holes.org)

    Physicists use supercomputers and AI to create the most accurate model yet of black hole mergers.

    One of the most cataclysmic events to occur in the cosmos involves the collision of two black holes. Formed from the deathly collapse of massive stars, black holes are incredibly compact—a person standing near a stellar-mass black hole would feel gravity about a trillion times more strongly than they would on Earth. When two objects of this extreme density spiral together and merge, a fairly common occurrence in space, they radiate more power than all the stars in the universe.

    “Imagine taking 30 suns and packing them into a region the size of Hawaii. Then take two such objects and accelerate them to half the speed of light and make them collide. This is one of the most violent events in nature,” says Vijay Varma, a graduate student at Caltech.

    In a new study in the January 11 issue of the journal Physical Review Letters, Varma and his colleagues report the most accurate computer model yet of the end stage of black hole mergers, a period when a new, more massive black hole has formed. The model, which was aided by supercomputers and machine-learning, or artificial intelligence (AI) tools, will ultimately help physicists perform more precise tests of Einstein’s general theory of relativity.

    “We can predict what’s left after a black hole merger—properties of the final black hole such as its spin and mass—with an accuracy 10 to 100 times better than what was possible before,” says co-author Davide Gerosa, an Einstein Postdoctoral Fellow in Theoretical Astrophysics at Caltech. “This is important because tests of general relativity depend on how well we can predict the end states of black hole mergers.”

    The research is related to a larger effort to study black holes with LIGO, the Laser Interferometer Gravitational-wave Observatory, which made history in 2015 by making the first direct detection of gravitational waves emitted by a black hole merger. Since then, LIGO has detected nine additional black hole mergers.

    Gravitational waves are ripples in space and time, first predicted by Einstein more than 100 years ago. Gravity itself, according to general relativity, is a warping of the fabric of spacetime. When massive objects like black holes accelerate through spacetime, they generate gravitational waves.

    One of the goals of LIGO and the thousands of scientists analyzing its data is to better understand the physics of black hole collisions—and to use these data, in turn, to assess whether Einstein’s general theory of relativity still holds true under these extreme conditions. A breakdown of the theory might open the door to new types of physics not yet imagined.

    But creating models of colossal events like black hole collisions has proved to be a daunting task. As the colliding black holes become very close to one another, just seconds before the final merger, their gravitational fields and velocities become extreme and the math becomes far too complex for standard analytical approaches.

    “When it comes to modeling these sources, one can use the pen-and-paper approach to solve Einstein’s equations during the early stages of the merger when the black holes are spiraling toward each other,” says Varma. “However, these schemes break down near the merger. Simulations using the equations of general relativity are the only means to predict the outcome of the merger process accurately.”

    That is where supercomputers help out. The team took advantage of nearly 900 black hole merger simulations previously run by the Simulating eXtreme Spacetimes (SXS) group using the Wheeler supercomputer at Caltech (supported by the Sherman Fairchild Foundation) and the Blue Waters supercomputer at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign. The simulations took 20,000 hours of computing time. The Caltech scientists’ new machine-learning program, or algorithm, learned from the simulations and helped create the final model.

    “Now that we have built the new model, you don’t need to take months,” says Varma. “The new model can give you answers about the end state of mergers in milliseconds.”

    The researchers say that their model will be of particular importance in a few years, as LIGO and other next-generation gravitational-wave detectors become more and more precise in their measurements. “Within the next few years or so, gravitational-wave detectors will have less noise,” says Gerosa. “The current models of the final black hole properties won’t be precise enough at that stage, and that’s where our new model can really help out.”

    The Physical Review Letters study, titled “High-accuracy mass, spin, and recoil predictions of generic black-hole merger remnants,” was funded by the Sherman Fairchild Foundation, the National Science Foundation, NASA, the Brinson Foundation, and Caltech. Other authors includealumnus Leo Stein (BS ’06) of the University of Mississippi and formerly a postdoctoral scholar at Caltech; François Hébert, a postdoctoral scholar at Caltech; and Hao Zhang of the University of Pennsylvania and formerly a Summer Undergraduate Research Fellow (SURF) at Caltech.


    3
    LIGO and Virgo Announce Four New Detections
    The observatories are also releasing their first catalog of gravitational-wave events
    4
    5

    On Saturday, December 1, scientists attending the Gravitational Wave Physics and Astronomy Workshop in College Park, Maryland, presented new results from the National Science Foundation’s LIGO (Laser Interferometer Gravitational-Wave Observatory) and the European- based VIRGO gravitational-wave detector regarding their searches for coalescing cosmic objects, such as pairs of black holes and pairs of neutron stars. The LIGO and Virgo collaborations have now confidently detected gravitational waves from a total of 10 stellar-mass binary black hole mergers and one merger of neutron stars, which are the dense, spherical remains of stellar explosions. Six of the black hole merger events had been reported before, while four are newly announced.

    From September 12, 2015, to January 19, 2016, during the first LIGO observing run since undergoing upgrades in a program called Advanced LIGO, gravitational waves from three binary black hole mergers were detected. The second observing run, which lasted from November 30, 2016, to August 25, 2017, yielded one binary neutron star merger and seven additional binary black hole mergers, including the four new gravitational-wave events being reported now. The new events are known as GW170729, GW170809, GW170818, and GW170823, in reference to the dates they were detected.

    All of the events are included in a new catalog, also released Saturday, with some of the events breaking records. For instance, the new event GW170729, detected in the second observing run on July 29, 2017, is the most massive and distant gravitational-wave source ever observed. In this coalescence, which happened roughly 5 billion years ago, an equivalent energy of almost five solar masses was converted into gravitational radiation.

    GW170814 was the first binary black hole merger measured by the three-detector network, and allowed for the first tests of gravitational-wave polarization (analogous to light polarization).

    The event GW170817, detected three days after GW170814, represented the first time that gravitational waves were ever observed from the merger of a binary neutron star system. What’s more, this collision was seen in gravitational waves and light, marking an exciting new chapter in multi-messenger astronomy, in which cosmic objects are observed simultaneously in different forms of radiation.

    One of the new events, GW170818, which was detected by the global network formed by the LIGO and Virgo observatories, was very precisely pinpointed in the sky. The position of the binary black holes, located 2.5 billion light-years from Earth, was identified in the sky with a precision of 39 square degrees. That makes it the next best localized gravitational-wave source after the GW170817 neutron star merger.

    Caltech’s Albert Lazzarini, Deputy Director of the LIGO Laboratory, says “The release of four additional binary black hole mergers further informs us of the nature of the population of these binary systems in the universe and better constrains the event rate for these types of events.”

    “In just one year, LIGO and VIRGO working together have dramatically advanced gravitational- wave science, and the rate of discovery suggests the most spectacular findings are yet to come,” says Denise Caldwell, Director of NSF’s Division of Physics. “The accomplishments of NSF’s LIGO and its international partners are a source of pride for the agency, and we expect even greater advances as LIGO’s sensitivity becomes better and better in the coming year.”

    “The next observing run, starting in Spring 2019, should yield many more gravitational-wave candidates, and the science the community can accomplish will grow accordingly,” says David Shoemaker, spokesperson for the LIGO Scientific Collaboration and senior research scientist in MIT’s Kavli Institute for Astrophysics and Space Research. “It’s an incredibly exciting time.”

    “It is gratifying to see the new capabilities that become available through the addition of Advanced Virgo to the global network,” says Jo van den Brand of Nikhef (the Dutch National Institute for Subatomic Physics) and VU University Amsterdam, who is the spokesperson for the Virgo Collaboration. “Our greatly improved pointing precision will allow astronomers to rapidly find any other cosmic messengers emitted by the gravitational-wave sources.” The enhanced pointing capability of the LIGO-Virgo network is made possible by exploiting the time delays of the signal arrival at the different sites and the so-called antenna patterns of the interferometers.

    “The new catalog is another proof of the exemplary international collaboration of the gravitational wave community and an asset for the forthcoming runs and upgrades”, adds EGO Director Stavros Katsanevas.

    The scientific papers describing these new findings, which are being initially published on the arXiv repository of electronic preprints, present detailed information in the form of a catalog of all the gravitational wave detections and candidate events of the two observing runs as well as describing the characteristics of the merging black hole population. Most notably, we find that almost all black holes formed from stars are lighter than 45 times the mass of the Sun. Thanks to more advanced data processing and better calibration of the instruments, the accuracy of the astrophysical parameters of the previously announced events increased considerably.

    Laura Cadonati, Deputy Spokesperson for the LIGO Scientific Collaboration, says “These new discoveries were only made possible through the tireless and carefully coordinated work of the detector commissioners at all three observatories, and the scientists around the world responsible for data quality and cleaning, searching for buried signals, and parameter estimation for each candidate — each a scientific specialty requiring enormous expertise and experience.”

    The Collaborations

    LIGO is funded by NSF and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council-OzGrav) making significant commitments and contributions to the project. More than 1,200 scientists from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration. A list of additional partners is available at https://my.ligo.org/census.php.

    The Virgo collaboration consists of more than 300 physicists and engineers belonging to 28 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; 11 from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in the Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with IFAE and the Universities of Valencia and Barcelona; two in Belgium with the Universities of Liege and Louvain; Jena University in Germany; and the European Gravitational Observatory (EGO), the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef. A list of the Virgo Collaboration can be found at http://public.virgo-gw.eu/the-virgo-collaboration/. More information is available on the Virgo website at http://www.virgo-gw.eu.

    Related Links

    Paper: “GWTC-1: A Gravitational-Wave Transient Catalog of Compact Binary Mergers Observed by LIGO and Virgo during the First and Second Observing Runs”

    Paper: “Binary Black Hole Population Properties Inferred from the First and Second Observing Runs of Advanced LIGO and Advanced Virgo”

    Papers available on the arXiv and the LIGO DCC, https://dcc.ligo.org/

    Media Contacts

    Valerio Boschi
    
Virgo-EGO Communication Office
    valerio.boschi@ego-gw.it; +39 050 752 463

    Antonella Varaschin
    
INFN Communications Office
    antonella.varaschin@presid.infn.it; +39 06 68400360

    Kimberly Allen

    Director of Media Relations and Deputy Director, MIT News Office
    allenkc@mit.edu; +1 617-253-2702

    Whitney Clavin

    Senior Content and Media Strategist
    Caltech Communications
    wclavin@caltech.edu; +1 626-395-1856

    John Toon

    Institute Research and Economic Development Communications
    Georgia Institute of Technology

    john.toon@comm.gatech.edu; +1 404-894-6986

    Amanda Hallberg Greenwell
    
Head, Office of Legislative and Public Affairs
    National Science Foundation
    agreenwe@nsf.gov; +1 703-292-8070

    See the full article here .

    See also “From UCSC: “Neutron stars, gravitational waves, and all the gold in the universe” here.


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 11:21 am on January 17, 2019 Permalink | Reply
    Tags: , Caltech,   

    From Caltech: “Lessons from the 1994 Northridge Quake” 

    Caltech Logo

    From Caltech

    01/17/2014 [Just now in social media]

    Written by Cynthia Eller
    Contact:
    Deborah Williams-Hedges
    (626) 395-3227
    debwms@caltech.edu

    1
    A portion of the Golden State Freeway in Gavin Canyon that collapsed during the 1994 Northridge earthquake. Credit: FEMA

    Current Earthquake Research at Caltech

    Since the magnitude 6.7 Northridge earthquake 20 years ago (January 17, 1994), researchers at the California Institute of Technology (Caltech) have learned much more about where earthquakes are likely to happen, and how danger to human life and damage to property might be mitigated when they do occur.

    “The Northridge quake really heralded the beginning of a new era in earthquake research, not only in southern California, but worldwide,” says Michael Gurnis, John E. and Hazel S. Smits Professor of Geophysics, and director of the Seismological Laboratory at Caltech.

    In the years just prior to the Northridge earthquake, Caltech launched a program called TERRAscope supported by the Whittier foundations, which placed high-quality seismic sensors near where earthquakes occur. The Northridge earthquake was, in effect, the first test of TERRAscope in which Caltech scientists could infer the distribution of an earthquake rupture on subsurface faults and directly measure the associated motion of the ground with greater accuracy. “With a modern digital seismic network, the potential of measuring ground shaking in real time presented itself,” says Gurnis. “The real time view also gave first responders detailed maps of ground shaking so that they could respond to those in need immediately after a quake,” adds Egill Hauksson, senior research associate at Caltech.

    To give us this new view of earthquakes, Caltech collaborated with the U.S. Geological Survey (USGS) and the California Geological Survey to form TriNet, through which a vastly expanded network of instrumentation was put in place across southern California. Concurrently, a new network of continuously operated GPS stations was permanently deployed by a group of geophysicists under the auspices of the Southern California Earthquake Center, funded by the USGS, NASA, NSF, and the Keck Foundation. GPS data are used to measure displacements as small as 1 millimeter per year between stations at any two locations, making it possible to track motions during, between, and after earthquakes. Similar and even larger networks of seismometers and GPS sensors have now been deployed across the United States, especially EarthScope, supported by the NSF, and in countries around the world by various respective national agencies like the networks deployed by the Japanese government.

    Initially, says Gurnis, there were not many large earthquakes to track with the new dense network of broadband seismic instruments and GPS devices. That all changed in December 2004 with the magnitude 9.3 earthquake and resulting tsunami that struck the Indian Ocean off the west coast of Sumatra, Indonesia. Quite abruptly, Caltech scientists had an enormous amount of information coming in from the instrumentation in Indonesia previously deployed by the Caltech Techtonics Observatory with support from the Gordon and Betty Moore Foundation. By the time the magnitude 9.0 Tohoku-Oki earthquake hit northern Japan in 2011, the Seismological Laboratory at Caltech had developed greatly expanded computing power capable of ingesting massive amounts of seismic and geodetic data. Within weeks of the disaster, a team led by Caltech professor of geophysics Mark Simons using data from GPS systems installed by the Japanese had produced extensive measurements of ground motion, as well as earthquake models constrained by this data, that provided new insight into the mechanics of plate tectonics and fault ruptures.

    The Tohoku-Oki earthquake was unprecedented: scientists estimate that over 50 meters of slip on the subsurface fault occurred during the devastating earthquake. Currently, scientists at Caltech and the Jet Propulsion Laboratory are prototyping new automated systems for exploiting the wealth of GPS and satellite imaging data to rapidly provide disaster assessment and situational awareness as events occur around the globe. “We are now at a juncture in time where new observational capabilities and available computational power will allow us to provide critical information with unprecedented speed and resolution,” says Simons.

    Earthquakes are notable—and, for many, particularly upsetting—because they have always come without warning. Earthquakes do in fact happen quickly and unpredictably, but not so much so that early-warning systems are impossible. In a Moore Foundation-supported collaboration with UC Berkeley, the University of Washington, and the USGS, Caltech is developing a prototype early-warning system that may provide seconds to tens of seconds of warning to people in areas about to experience ground shaking, and minutes of warning to people potentially in the path of a tsunami. Japan invested heavily in an earthquake early-warning system after the magnitude 6.9 Kobe earthquake that occurred January 17, 1995, on the one-year anniversary of the Northridge earthquake, and the system performed well during the Tohoku-Oki earthquake. “It was a major scientific and technological accomplishment,” says Gurnis. “High-speed rail trains slowed and stopped as earthquake warnings came in, and there were no derailments as a result of the quake.”

    Closer to home, Caltech professor of geophysics Robert Clayton has aided local earthquake detection by distributing wallet-sized seismometers to residents of the greater Pasadena area to keep in their homes. The seismometers are attached to a USB drive on each resident’s computer, which is to remain on at all times. The data from these seismometers serve two functions: they record seismic activity on a detailed block-by-block scale, and, in the event of a large earthquake, they can help identify areas that are hardest hit. One lesson learned in the Northridge earthquake was that serious damage can occur far from the epicenter of an earthquake. The presence of many seismometers could help first responders to find the worst-affected areas more quickly after an earthquake strikes.

    Caltech scientists have also been playing a leading role in the large multi-institutional Salton Seismic Imaging Project. The project is mapping the San Andreas fault and discovering additional faults by setting off underground explosions and underwater bursts of compressed air and then measuring the transmission of the resulting sound waves and vibrations through sediment. According to Joann Stock, professor of geology and geophysics at Caltech, knowing the geometry of faults and the composition of nearby sediments informs our understanding of the types of earthquakes that will occur in the future, and the reaction of the local sediment to ground shaking.

    In addition, Caltech scientists learned much through simulating—via both computer modeling and physical modeling techniques—how earthquakes occur and what they leave in their aftermath.

    Computer simulations of how buildings respond during earthquakes recently allowed Caltech professors Thomas Heaton, professor of engineering seismology, and John Hall, professor of civil engineering, to estimate the decrease in building safety caused by the existence of defective welds in steel-frame structures, a problem identified after the Northridge earthquake. Researchers simulated the behavior of different 6- and 20-story building models in a variety of potential earthquake scenarios created by the Southern California Earthquake Center for the Los Angeles and San Francisco areas. The study showed that defective welds make a building significantly more susceptible to collapse and irreparable damage, and also found that stiffer, higher-strength buildings perform better than more flexible, lower-strength designs.

    Caltech professor of mechanical engineering and geophysics Nadia Lapusta recently used computer simulations of numerous earthquakes to determine what role “creeping” fault slip might play in earthquake events. It has been known for some time that, in addition to the rapid displacements that trigger earthquakes, land also slips very slowly along fault lines, a process that was thought to stop incoming earthquake rupture. Instead, Lapusta’s models show that these “stable segments” may become seismically active in an earthquake, accelerating and even strengthening its motions. Lapusta hypothesizes that this was one factor behind the severity of the 2011 Tohoku-Oki earthquake. Taking advantage of advances in computer modeling, Lapusta and her colleague Jean-Philippe Avouac, Earle C. Anthony Professor of Geology at Caltech, have created a comprehensive model of a fault zone, including both its earthquake activity and its behavior in seismically quiet times.

    Physical modeling of earthquakes is carried out at Caltech via collaborative efforts between the Divisions of Geological and Planetary Sciences and of Engineering and Applied Science. A series of experiments conducted by Ares Rosakis, the Theodore von Kármán Professor of Aeronautics and Mechanical Engineering, and collaborators including Lapusta and Hiroo Kanamori, the John E. and Hazel S. Smits Professor of Geophysics, Emeritus, used polymer plates to simulate land masses. Stresses were then created at various angles to the fault lines between the plates to set off earthquake-like activity. The motion in the polymer plates was measured by laser vibrometers while a high-speed camera recorded the movements in detail, yielding unprecedented data on the propagation of seismic waves. Researchers learned that strike-slip faults like the San Andreas may rupture in more than one direction (it was previously believed that these faults had a preferred direction), and that in addition to sliding along a fault, ruptures may occur in a “self-healing” pulselike manner in which a seismic wave “crawls” down a fault line. A third study drew conclusions about how faults will behave—in either a classic cracklike sliding rupture or in a pulselike rupture—depending on the angle at which compression forces strike the fault.

    “Northridge was a devastating earthquake for Los Angeles, and there was a massive amount of damage,” Gurnis says, “But in some sense, we stepped up to the plate after Northridge to determine what we could do better. And as a result we have ushered in an era of dense, high-fidelity geophysical networks on top of hazardous faults. We’ve exploited these networks to better understand how earthquakes occur, and we’ve pushed the limits such that we are now at the dawn of a new era of earthquake early warning in the United States. That’s because of Northridge.”

    See the full article here .

    Earthquake Alert

    1

    Earthquake Alert

    Earthquake Network projectEarthquake Network is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

    The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 1:51 pm on January 10, 2019 Permalink | Reply
    Tags: , , , Caltech, , , , , Radio magnetars, The team looked at the magnetar named PSR J1745-2900 located in the Milky Way's galactic center using the largest of NASA's Deep Space Network radio dishes in Australia   

    From Caltech: “Magnetar Mysteries in our Galaxy and Beyond” 

    Caltech Logo

    From Caltech

    01/09/2019

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Illustration of a magnetar—a rotating neutron star with incredibly powerful magnetic fields.
    Credit: NASA/CXC/M.Weiss

    2
    The 70-meter radio dish (DSS-43) in Canberra, Australia, part of NASA’s Deep Space Network.
    Credit: NASA/DSN

    New research looks at possible links between magnetars and extragalactic radio bursts.

    In a new Caltech-led study, researchers from campus and the Jet Propulsion Laboratory (JPL) have analyzed pulses of radio waves coming from a magnetar—a rotating, dense, dead star with a strong magnetic field—that is located near the supermassive black hole at the heart of the Milky Way galaxy. The new research provides clues that magnetars like this one, lying in close proximity to a black hole, could perhaps be linked to the source of “fast radio bursts,” or FRBs. FRBs are high-energy blasts that originate beyond our galaxy but whose exact nature is unknown.

    “Our observations show that a radio magnetar can emit pulses with many of the same characteristics as those seen in some FRBs,” says Caltech graduate student Aaron Pearlman, who presented the results today at the 233rd meeting of the American Astronomical Society in Seattle. “Other astronomers have also proposed that magnetars near black holes could be behind FRBs, but more research is needed to confirm these suspicions.”

    The research team was led by Walid Majid, a visiting associate at Caltech and principal research scientist at JPL, which is managed by Caltech for NASA, and Tom Prince, the Ira S. Bowen Professor of Physics at Caltech. The team looked at the magnetar named PSR J1745-2900, located in the Milky Way’s galactic center, using the largest of NASA’s Deep Space Network radio dishes in Australia. PSR J1745-2900 was initially spotted by NASA’s Swift X-ray telescope, and later determined to be a magnetar by NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR), in 2013.

    NASA Neil Gehrels Swift Observatory

    NASA NuSTAR X-ray telescope

    “PSR J1745-2900 is an amazing object. It’s a fascinating magnetar, but it also has been used as a probe of the conditions near the Milky Way’s supermassive black hole,” says Fiona Harrison, the Benjamin M. Rosen Professor of Physics at Caltech and the principal investigator of NuSTAR. “It’s interesting that there could be a connection between PSR J1745-2900 and the enigmatic FRBs.”

    Magnetars are a rare subtype of a group of objects called pulsars; pulsars, in turn, belong to a class of rotating dead stars known as neutron stars. Magnetars are thought to be young pulsars that spin more slowly than ordinary pulsars and have much stronger magnetic fields, which suggests that perhaps all pulsars go through a magnetar-like phase in their lifetime.

    Women in STEM – Dame Susan Jocelyn Bell Burnell

    Dame Susan Jocelyn Bell Burnell, discovered pulsars with radio astronomy. Jocelyn Bell at the Mullard Radio Astronomy Observatory, Cambridge University, taken for the Daily Herald newspaper in 1968. Denied the Nobel.

    The magnetar PSR J1745-2900 is the closest-known pulsar to the supermassive black hole at the center of the galaxy, separated by a distance of only 0.3 light-years, and it is the only pulsar known to be gravitationally bound to the black hole and the environment around it.

    In addition to discovering similarities between the galactic-center magnetar and FRBs, the researchers also gleaned new details about the magnetar’s radio pulses. Using one of the Deep Space Network’s largest radio antennas, the scientists were able to analyze individual pulses emitted by the star every time it rotated, a feat that is very rare in radio studies of pulsars. They found that some pulses were stretched, or broadened, by a larger amount than predicted when compared to previous measurements of the magnetar’s average pulse behavior. Moreover, this behavior varied from pulse to pulse.

    “We are seeing these changes in the individual components of each pulse on a very fast time scale. This behavior is very unusual for a magnetar,” says Pearlman. The radio components, he notes, are separated by only 30 milliseconds on average.

    One theory to explain the signal variability involves clumps of plasma moving at high speeds near the magnetar. Other scientists have proposed that such clumps might exist but, in the new study, the researchers propose that the movement of these clumps may be a possible cause of the observed signal variability. Another theory proposes that the variability is intrinsic to the magnetar itself.

    “Understanding this signal variability will help in future studies of both magnetars and pulsars at the center of our galaxy,” says Pearlman.

    In the future, Pearlman and his colleagues hope to use the Deep Space Network radio dish to solve another outstanding pulsar mystery: Why are there so few pulsars near the galactic center? Their goal is to find a non-magnetar pulsar near the galactic-center black hole.

    “Finding a stable pulsar in a close, gravitationally bound orbit with the supermassive black hole at the galactic center could prove to be the Holy Grail for testing theories of gravity,” says Pearlman. “If we find one, we can do all sorts of new, unprecedented tests of Albert Einstein’s general theory of relativity.”

    The new study, titled, “Pulse Morphology of the Galactic Center Magnetar PSR J1745-2900,” appeared in the October 20, 2018, issue of The Astrophysical Journal and was funded by a Research and Technology Development grant through a contract with NASA; JPL and Caltech’s President’s and Director’s Fund; the Department of Defense; and the National Science Foundation. Other authors include Jonathon Kocz of Caltech and Shinji Horiuchi of the CSIRO (Commonwealth Scientific and Industrial Research Organization) Astronomy & Space Science, Canberra Deep Space Communication Complex.

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
  • richardmitnick 2:56 pm on December 18, 2018 Permalink | Reply
    Tags: Caltech, , Gaia 17bpi, , The star belongs to a class of fitful stars known as FU Ori's, Young Star Caught in a Fit of Growth   

    From Caltech: “Young Star Caught in a Fit of Growth” 

    Caltech Logo

    From Caltech

    12/18/2018

    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    This illustration shows a young star undergoing a growth spurt. Top panel: Material from the dusty and gas-rich disk (orange) plus hot gas (blue) mildly flows onto the star, creating a hot spot. Middle panel: The outburst begins—the inner disk is heated, more material flows to the star, and the disk creeps inward. Lower panel: The outburst is in full throttle, with the inner disk merging into the star and gas flowing outward (green).

    2
    The location of Gaia 17bpi, which lies in the Sagitta constellation, is indicated in the center of this image taken by NASA’s Spitzer Space Telescope. Credit: NASA/JPL-Caltech/M. Kuhn (Caltech)

    New visible and infrared observations of young star reveal clues about how it bulks up.

    Researchers have discovered a young star in the midst of a rare growth spurt—a dramatic phase of stellar evolution when matter swirling around a star falls onto the star, bulking up its mass. The star belongs to a class of fitful stars known as FU Ori’s, named after the original member of the group, FU Orionis (the capital letters represent a naming scheme for variable stars, and Orionis refers to its location in the Orion constellation). Typically, these stars, which are less than a few million years old, are hidden behind thick clouds of dust and hard to observe. This new object is only the 25th member of this class found to date and one of only about a dozen caught in the act of an outburst.

    “These FU Ori events are extremely important in our current understanding of the process of star formation but have remained almost mythical because they have been so difficult to observe,” says Lynne Hillenbrand, professor of astronomy at Caltech and lead author of a new report on the findings appearing in The Astrophysical Journal. “This is actually the first time we’ve ever seen one of these events as it happens in both optical and infrared light, and these data have let us map the movement of material through the disk and onto the star.”

    The newfound star, called Gaia 17bpi, was first spotted by the European Space Agency’s Gaia satellite, which scans the sky continuously, making precise measurements of stars in visible light.

    ESA/GAIA satellite

    When Gaia spots a change in a star’s brightness, an alert goes out to the astronomy community. A graduate student at the University of Exeter and co-author of the new study, Sam Morrell, was the first to notice that the star had brightened. Other members of the team then followed up and discovered that the star’s brightening had been serendipitously captured in infrared light by NASA’s asteroid-hunting NEOWISE satellite at the same time that Gaia saw it, as well as one-and-a-half-years earlier.

    NASA Wise Telescope

    “While NEOWISE’s primary mission is detecting nearby solar system objects, it also images all of the background stars and galaxies as it sweeps around the sky every six months,” says co-author Roc Cutri, lead scientist for the NEOWISE Data Center at IPAC, an astronomy and data center at Caltech. “NEOWISE has been surveying in this way for five years now, so it is very effective for detecting changes in the brightness of objects.”

    NASA’s infrared-sensing Spitzer Space Telescope also happened to have witnessed the beginning of the star’s brightening phase twice back in 2014, giving the researchers a bonanza of infrared data.

    NASA/Spitzer Infrared Telescope

    The new findings shine light on some of the longstanding mysteries surrounding the evolution of young stars. One unanswered question is: How does a star acquire all of its mass? Stars form from collapsing balls of gas and dust. With time, a disk of material forms around the star, and the star continues to siphon material from this disk. But, according to previous observations, stars do not pull material onto themselves fast enough to reach their final masses.

    Theorists believe that FU Ori events—in which mass is dumped from the disk onto the star over a total period of about 100 years—may help solve the riddle. The scientists think that all stars undergo around 10 to 20 or so of these FU Ori events in their lifetimes but, because this stellar phase is often hidden behind dust, the data are limited. “Somebody sketched this scenario on the back of an envelope in the 1980s, and, after all this time, we still haven’t done much better at determining the event rates,” says Hillenbrand.

    The new study shows, with the most detail yet, how material moves from the midrange of a disk, in a region located around 1 astronomical unit from the star, to the star itself. (An astronomical unit is the distance between Earth and the sun.) NEOWISE and Spitzer were the first to pick up signs of the buildup of material in the middle of the disk. As the material started to accumulate in the disk, it warmed up, giving off infrared light. Then, as this material fell onto the star, it heated up even more, giving off visible light, which is what Gaia detected.

    “The material in the middle of the disk builds up in density and becomes unstable,” says Hillenbrand. “Then it drains onto the star, manifesting as an outburst.”

    The researchers used the W. M. Keck Observatory and Caltech’s Palomar Observatory to help confirm the FU Ori nature of the newfound star. Says Hillenbrand, “You can think of Gaia as discovering the initial crime scene, while Keck and Palomar pointed us to the smoking gun.”


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level,


    Caltech Palomar Observatory, located in San Diego County, California, US, at 1,712 m (5,617 ft)

    The study is titled, “Gaia 17bpi: An FU Ori Type Outburst.” Other authors include: Carlos Contreras Peña and Tim Naylor of the University of Exeter; Michael Kuhn and Luisa Rebull of Caltech; Simon Hodgkin of Cambridge University; Dirk Froebrich of the University of Kent; and Amy Mainzer of JPL.

    See the full article here .


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


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus


    Caltech campus

     
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