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  • richardmitnick 1:24 pm on August 25, 2021 Permalink | Reply
    Tags: "Cosmic Rays May Be Key to Understanding Galactic Dynamics", American Institute of Physics-AIP (US), , , Cosmic rays are charged subnuclear particles that move close to the speed of light and constantly raining down on the Earth., Cosmic rays may help explain aspects of our galaxy from its smallest scales such as protoplanetary disks and planets to its largest scales such as galactic winds., , Supernova shock waves expanding the interstellar/intergalactic medium are known to accelerate cosmic rays., The big question is how cosmic rays deposit their momentum into the background plasma that composes the interstellar medium.   

    From American Institute of Physics-AIP (US) : “Cosmic Rays May Be Key to Understanding Galactic Dynamics” 

    From American Institute of Physics-AIP (US)

    August 24, 2021

    Larry Frum
    media@aip.org
    301-209-3090

    From the Journal: Physics of Plasmas

    Cosmic rays are charged subnuclear particles that move close to the speed of light and constantly raining down on the Earth. These particles are relativistic, as defined by Albert Einstein’s special relativity, and manage to generate a magnetic field that controls the way they move within the galaxy.

    Gas within the interstellar medium is composed of atoms, mostly hydrogen and mostly ionized, meaning its protons and electrons are separated. While moving around within this gas, cosmic rays kickstart the background protons, which causes a collective plasma wave movement akin to the ripples on a lake when you toss in a stone.

    1
    This illustration shows how waves and particles interact — wave amplitude is growing while particle drift speed is dropping due to scattering. CREDIT: A. Marcowith, A.J. van Marle, and I. Plotnikov.

    The big question is how cosmic rays deposit their momentum into the background plasma that composes the interstellar medium. In Physics of Plasmas, from AIP Publishing, plasma astrophysicists in France review recent developments within the field of studying the streaming instability triggered by cosmic rays within astrophysical and space plasma.

    “Cosmic rays may help explain aspects of our galaxy from its smallest scales such as protoplanetary disks and planets to its largest scales such as galactic winds,” said Alexandre Marcowith, from the University of Montpellier [Université de Montpellier] (FR).

    Until now, cosmic rays were viewed as being a bit apart within galaxy “ecology.” But because instability works well and is stronger than expected around cosmic ray sources, such as supernova remnants and pulsars, these particles likely have far more impacts on galactic dynamics and the star formation cycle than previously known.

    “This is not really a surprise, but more of a paradigm shift,” Marcowith said. “In science and astrophysics, everything is connected.”

    Supernova shock waves expanding the interstellar/intergalactic medium “are known to accelerate cosmic rays, and because cosmic rays are streaming away, they may have contributed to generating the magnetic field seeds necessary to explain the actual magnetic field strengths we observe around us,” said Marcowith.

    After the amplitude of a plasma wave is reduced or damped over time, much like those generated by a stone thrown into a lake, it heats the gas of the plasma. Meanwhile, it helps scatter cosmic rays.

    For this to occur, the waves need wavelengths of the same order as the cosmic ray gyro radius. Cosmic rays possess a helical (spiral) motion around the magnetic field, and its radius is called the Larmor radius.

    “Say you are driving a car on a winding road. If the wavelength is of the same order as your wheel size, it will be difficult to drive,” said Marcowith.

    Cosmic rays are strongly scattered by these waves, and the main instability at the origin of these perturbations (waves) is the streaming instability associated with the collective streaming motion of cosmic rays.

    “There are several fields of research in astrophysics using similar numerical techniques to investigate the impact of this streaming instability within different astrophysical contexts such as supernova remnants and jets,” said Marcowith. “This instability and turbulence it creates may be the source of many astrophysical phenomena, and it shows how cosmic rays play a role in the big circus of our Milky Way.”

    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 American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

    The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

    Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

    Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

    Member societies:
    Acoustical Society of America
    American Association of Physicists in Medicine
    American Association of Physics Teachers
    American Astronomical Society
    American Crystallographic Association
    American Meteorological Society
    American Physical Society
    American Vacuum Society

    Affiliated societies

    American Association for the Advancement of Science, Section on Physics
    American Chemical Society, Division of Physical Chemistry
    American Institute of Aeronautics and Astronautics
    American Nuclear Society
    American Society of Civil Engineers
    ASM International
    Astronomical Society of the Pacific
    Biomedical Engineering Society
    Council on Undergraduate Research, Physics & Astronomy Division
    Electrochemical Society
    Geological Society of America
    IEEE Nuclear and Plasma Sciences Society
    International Association of Mathematical Physics
    International Union of Crystallography
    International Centre for Diffraction Data
    Health Physics Society

     
  • richardmitnick 10:06 am on May 26, 2021 Permalink | Reply
    Tags: "Probing Deeper into Origins of Cosmic Rays", American Institute of Physics-AIP (US), ,   

    From American Institute of Physics-AIP (US) : “Probing Deeper into Origins of Cosmic Rays” 

    From American Institute of Physics-AIP (US)

    May 25, 2021
    Salvatore Buonocore
    Mihir Sen

    For more information:
    Larry Frum
    media@aip.org
    301-209-3090

    1
    Schematic representation of cosmic rays propagating through magnetic clouds. CREDIT: Salvatore Buonocore.

    Cosmic rays are high-energy atomic particles continually bombarding Earth’s surface at nearly the speed of light. Our planet’s magnetic field shields the surface from most of the radiation generated by these particles. Still, cosmic rays can cause electronic malfunctions and are the leading concern in planning for space missions.

    Researchers know cosmic rays originate from the multitude of stars in the Milky Way, including our sun, and other galaxies. The difficulty is tracing the particles to specific sources, because the turbulence of interstellar gas, plasma, and dust causes them to scatter and rescatter in different directions.

    In AIP Advances, by AIP Publishing, University of Notre Dame (US) researchers developed a simulation model to better understand these and other cosmic ray transport characteristics, with the goal of developing algorithms to enhance existing detection techniques.

    Brownian motion theory is generally employed to study cosmic ray trajectories. Much like the random motion of pollen particles in a pond, collisions between cosmic rays within fluctuating magnetic fields cause the particles to propel in different directions.

    But this classic diffusion approach does not adequately address the different propagation rates affected by diverse interstellar environments and long spells of cosmic voids. Particles can become trapped for a time in magnetic fields, which slow them down, while others are thrust into higher speeds through star explosions.

    To address the complex nature of cosmic ray travel, the researchers use a stochastic scattering model, a collection of random variables that evolve over time. The model is based on geometric Brownian motion, a classic diffusion theory combined with a slight trajectory drift in one direction.

    In their first experiment, they simulated cosmic rays moving through interstellar space and interacting with localized magnetized clouds, represented as tubes. The rays travel undisturbed over a long period of time. They are interrupted by chaotic interaction with the magnetized clouds, resulting in some rays reemitting in random directions and others remaining trapped.

    Monte Carlo numerical analysis, based on repeated random sampling, revealed ranges of density and reemission strengths of the interstellar magnetic clouds, leading to skewed, or heavy-tailed, distributions of the propagating cosmic rays.

    The analysis denotes marked superdiffusive behavior. The model’s predictions agree well with known transport properties in complex interstellar media.

    “Our model provides valuable insights on the nature of complex environments crossed by cosmic rays and could help advance current detection techniques,” author Salvatore Buonocore said.

    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 American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

    The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

    Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

    Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

    Member societies:
    Acoustical Society of America
    American Association of Physicists in Medicine
    American Association of Physics Teachers
    American Astronomical Society
    American Crystallographic Association
    American Meteorological Society
    American Physical Society
    American Vacuum Society

    Affiliated societies

    American Association for the Advancement of Science, Section on Physics
    American Chemical Society, Division of Physical Chemistry
    American Institute of Aeronautics and Astronautics
    American Nuclear Society
    American Society of Civil Engineers
    ASM International
    Astronomical Society of the Pacific
    Biomedical Engineering Society
    Council on Undergraduate Research, Physics & Astronomy Division
    Electrochemical Society
    Geological Society of America
    IEEE Nuclear and Plasma Sciences Society
    International Association of Mathematical Physics
    International Union of Crystallography
    International Centre for Diffraction Data
    Health Physics Society

     
  • richardmitnick 5:34 pm on April 20, 2021 Permalink | Reply
    Tags: "Combining Light and Superconductors Could Boost AI Capabilities", American Institute of Physics-AIP (US), , By operating at low temperature superconducting electronic circuits; single-photon detectors; silicon light sources we will open a path toward rich functionality and scalable fabrication., , , , The fabrication of silicon chips with electronic and photonic circuit elements is difficult for many physical and practical reasons related to the materials used for the components.   

    From American Institute of Physics-AIP (US) : “Combining Light and Superconductors Could Boost AI Capabilities” 

    From American Institute of Physics-AIP (US)

    April 20, 2021
    Larry Frum
    media@aip.org
    301-209-3090

    1
    Spatial hierarchy. CREDIT: Jeffrey Michael Shainline.

    As artificial intelligence has attracted broad interest, researchers are focused on understanding how the brain accomplishes cognition so they can construct artificial systems with general intelligence comparable to humans’ intelligence.

    Many have approached this challenge by using conventional silicon microelectronics in conjunction with light. However, the fabrication of silicon chips with electronic and photonic circuit elements is difficult for many physical and practical reasons related to the materials used for the components.

    In Applied Physics Letters, by AIP Publishing, researchers at the National Institute of Standards and Technology (US) propose an approach to large-scale artificial intelligence that focuses on integrating photonic components with superconducting electronics rather than semiconducting electronics.

    “We argue that by operating at low temperature and using superconducting electronic circuits; single-photon detectors; and silicon light sources we will open a path toward rich computational functionality and scalable fabrication,” said author Jeffrey Shainline.

    Using light for communication in conjunction with complex electronic circuits for computation could enable artificial cognitive systems of scale and functionality beyond what can be achieved with either light or electronics alone.

    “What surprised me most was that optoelectronic integration may be much easier when working at low temperatures and using superconductors than when working at room temperatures and using semiconductors,” said Shainline.

    Superconducting photon detectors enable detection of a single photon, while semiconducting photon detectors require about 1,000 photons. So not only do silicon light sources work at 4 kelvins, but they also can be 1,000 times less bright than their room temperature counterparts and still communicate effectively.

    Some applications, such as chips in cellphones, require working at room temperature, but the proposed technology would still have wide reaching applicability for advanced computing systems.

    The researchers plan to explore more complex integration with other superconducting electronic circuits as well as demonstrate all the components that comprise artificial cognitive systems, including synapses and neurons.

    Showing that the hardware can be manufactured in a scalable manner, so large systems can be realized at a reasonable cost, will also be important. Superconducting optoelectronic integration could also help create scalable quantum technologies based on superconducting or photonic qubits. Such quantum-neural hybrid systems may also lead to new ways of leveraging the strengths of quantum entanglement with spiking neurons.

    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 American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

    The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

    Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

    Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

    Member societies:
    Acoustical Society of America
    American Association of Physicists in Medicine
    American Association of Physics Teachers
    American Astronomical Society
    American Crystallographic Association
    American Meteorological Society
    American Physical Society
    American Vacuum Society

    Affiliated societies

    American Association for the Advancement of Science, Section on Physics
    American Chemical Society, Division of Physical Chemistry
    American Institute of Aeronautics and Astronautics
    American Nuclear Society
    American Society of Civil Engineers
    ASM International
    Astronomical Society of the Pacific
    Biomedical Engineering Society
    Council on Undergraduate Research, Physics & Astronomy Division
    Electrochemical Society
    Geological Society of America
    IEEE Nuclear and Plasma Sciences Society
    International Association of Mathematical Physics
    International Union of Crystallography
    International Centre for Diffraction Data
    Health Physics Society

     
  • richardmitnick 2:02 pm on April 20, 2021 Permalink | Reply
    Tags: American Institute of Physics-AIP (US), , The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy,   

    From American Institute of Physics-AIP (US) via phys.org : “Boosting fiber optics communications with advanced quantum-enhanced receiver” 

    From American Institute of Physics-AIP (US)

    via

    phys.org

    April 20, 2021

    1
    Illustration showing how single-photon detection is used for feedback. Once correct parameters for the reference beam are established, the input state is extinguished. Credit: Ivan Burenkov.

    Fiber optic technology is the holy grail of high-speed, long-distance telecommunications. Still, with the continuing exponential growth of internet traffic, researchers are warning of a capacity crunch.

    In AVS Quantum Science, researchers from the National Institute of Standards and Technology (US) and the University of Maryland (US) show how quantum-enhanced receivers could play a critical role in addressing this challenge.

    The scientists developed a method to enhance receivers based on quantum physics properties to dramatically increase network performance while significantly reducing the error bit rate (EBR) and energy consumption.

    Fiber optic technology relies on receivers to detect optical signals and convert them into electrical signals. The conventional detection process, largely as a result of random light fluctuations, produces ‘shot noise,’ which decreases detection ability and increases EBR.

    To accommodate this problem, signals must continually be amplified as pulsating light becomes weaker along the optic cable, but there is a limit to maintaining adequate amplification when signals become barely perceptible.

    Quantum-enhanced receivers that process up to two bits of classical information and can overcome the shot noise have been demonstrated to improve detection accuracy in laboratory environments. In these and other quantum receivers, a separate reference beam with a single-photon detection feedback is used so the reference pulse eventually cancels out the input signal to eliminate the shot noise.

    The researchers’ enhanced receiver, however, can decode as many as four bits per pulse, because it does a better job in distinguishing among different input states.

    To accomplish more efficient detection, they developed a modulation method and implemented a feedback algorithm that takes advantage of the exact times of single photon detection. Still, no single measurement is perfect, but the new holistically designed communication system yields increasingly more accurate results on average.

    “We studied the theory of communications and the experimental techniques of quantum receivers to come up with a practical telecommunication protocol that takes maximal advantage of the quantum measurement,” author Sergey Polyakov said. “With our protocol, because we want the input signal to contain as few photons as possible, we maximize the chance that the reference pulse updates to the right state after the very first photon detection, so at the end of the measurement, the EBR is minimized.”

    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 American Institute of Physics (AIP) promotes science and the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies. Its corporate headquarters are at the American Center for Physics in College Park, Maryland, but the institute also has offices in Melville, New York, and Beijing.

    The focus of the AIP appears to be organized around a set of core activities. The first delineated activity is to support member societies regarding essential society functions. This is accomplished by annually convening the various society officers to discuss common areas of concern. A range of topics is discussed which includes scientific publishing, public policy issues, membership-base issues, philanthropic giving, science education, science careers for a diverse population, and a forum for sharing ideas.

    Another core activity is publishing the science of physics in research journals, magazines, and conference proceedings. Member societies continue nevertheless to publish their own journals.

    Other core activities are tracking employment and education trends with six decades of coverage, being a liaison between research science and industry, historical collections and physics outreach programs, and supporting science education initiatives and supporting undergraduate physics. One other core activity is as an advocate for science policy to the U.S. Congress and the general public.

    Member societies:
    Acoustical Society of America
    American Association of Physicists in Medicine
    American Association of Physics Teachers
    American Astronomical Society
    American Crystallographic Association
    American Meteorological Society
    American Physical Society
    American Vacuum Society

    Affiliated societies

    American Association for the Advancement of Science, Section on Physics
    American Chemical Society, Division of Physical Chemistry
    American Institute of Aeronautics and Astronautics
    American Nuclear Society
    American Society of Civil Engineers
    ASM International
    Astronomical Society of the Pacific
    Biomedical Engineering Society
    Council on Undergraduate Research, Physics & Astronomy Division
    Electrochemical Society
    Geological Society of America
    IEEE Nuclear and Plasma Sciences Society
    International Association of Mathematical Physics
    International Union of Crystallography
    International Centre for Diffraction Data
    Health Physics Society

     
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