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  • richardmitnick 4:41 pm on February 19, 2020 Permalink | Reply
    Tags: , , , BECEP telescope array at South Pole Telescope, CMB - Cosmic Microwave Background, ,   

    From University of Minnesota Twin Cities: “BECEP array installed at South Pole” 

    u-minnesota-bloc

    From University of Minnesota Twin Cities

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    Members of the BICEP collaboration enjoying an Antarctic summer day in front of the new BICEP Array Telescope at the South Pole. Clem Pryke

    Professor Clem Pryke and his group are on their way back to Minnesota from the South Pole in Antarctica after completing installation of the new BICEP Array Telescope. Over the next few years this specialized radio telescope will study the Cosmic Microwave Background [CMB] – an afterglow from the Big Bang – looking for the imprint of gravitational waves from the beginning of time.

    CMB per ESA/Planck

    The project, which has been several years in the making, is a collaboration between the University of Minnesota, Caltech, Harvard and Stanford.

    The telescope mount is a large, custom built machine which moves and points the radio receivers on the sky. The pieces of the apparatus were delivered to a large assembly hall at the University of Minnesota in the summer of 2018. There then followed an intensive year-long process of turning the raw platform into a fully-fledged telescope complete with drive system, receivers, cryogenic refrigerators, electronics and environmental protection equal to the extreme polar temperatures (-30F in summer and -110F in winter). Then, late last summer, the entire system was broken back down into component parts, packed into crates, and shipped out to the South Pole (via California, New Zealand and McMurdo Station on the coast of Antarctica).

    At the South Pole there is one day-night cycle per year and the Station is accessible only during the southern hemisphere summer (from November to February). During this period the on-site team reassembled the new telescope and and brought all of the complex supporting systems online.

    Now with the departure of the main team, a single UMN scientist will remain through the six month Antarctic winter night to keep the telescope operating as it records its scientific data. The new telescope is the most sensitive of its type in the world and will continue the quest to understand the physics which governed the very beginning of our universe.

    More information at http://biceparray.wordpress.com/

    See the full article here .

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    u-minnesota-campus-twin-cities

    The University of Minnesota, Twin Cities (often referred to as the U of M, UMN, Minnesota, or simply the U) is a public research university in Minneapolis and Saint Paul, MN. The Twin Cities campus comprises locations in Minneapolis and St. Paul approximately 3 miles (4.8 km) apart, and the St. Paul location is in neighboring Falcon Heights. The Twin Cities campus is the oldest and largest in the University of Minnesota system and has the sixth-largest main campus student body in the United States, with 51,327 students in 2019-20. It is the flagship institution of the University of Minnesota System, and is organized into 19 colleges, schools, and other major academic units.

    The University was included in a list of Public Ivy universities in 2001. Legislation passed in 1851 to develop the university, and the first college classes were held in 1867. The university is categorized as a Doctoral University – Highest Research Activity (R1) in the Carnegie Classification of Institutions of Higher Education. Minnesota is a member of the Association of American Universities and is ranked 14th in research activity, with $881 million in research and development expenditures in the fiscal year ending June 30, 2015.

    University of Minnesota faculty, alumni, and researchers have won 26 Nobel Prizes and three Pulitzer Prizes. Notable University of Minnesota alumni include two vice presidents of the United States, Hubert Humphrey and Walter Mondale.

     
  • richardmitnick 8:36 pm on January 13, 2020 Permalink | Reply
    Tags: , , , Calculate the masses of enormous galaxy clusters using a new mathematical estimator., CMB - Cosmic Microwave Background, , , , Destination: Antarctica-the South Pole Telescope., Destination: Chile-Cerro Tololo Inter-American Observatory-The Dark Energy Camera of the Dark Energy Survey, Destination: Unspoiled places-, , Most of the mass of galaxy clusters isn’t even visible – it’s dark matter.   

    From Fermi National Accelerator Lab: “Data from antipodal places: First use of CMB polarization to detect gravitational lensing from galaxy clusters” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    January 13, 2020
    Catherine N. Steffel

    Galaxies. Amalgamations of stars, interstellar gas, dust, stellar debris and dark matter. They waltz through the cold universe, gravity nurturing their embrace. Occasionally, galaxies snowball into enormous galaxy clusters with masses averaging 100 trillion times that of our sun.

    But this wasn’t always the case.

    In the infant universe, temperatures were so high that electrons and protons were too hot to form atoms. Everything was a hot, ionized gas, not unlike the surface of the sun.

    Over the next 400,000 years, the universe expanded and cooled to around 3,000 degrees Celsius, about the temperature of an industrial furnace. At these temperatures, electrons and protons combined into hydrogen atoms and released photons in the process. This light, called the cosmic microwave background radiation, has been traveling through space ever since, a watermark of space and time.

    Now, scientists have found new ways to tease information out of this inexhaustible time machine.

    Constraining cosmology with CMB polarization

    In a study published in Physical Review Letters, Fermilab and University of Chicago scientist Brad Benson and colleagues use the polarization, or orientation, of the cosmic microwave background [CMB] to calculate the masses of enormous galaxy clusters using a new mathematical estimator.

    CMB per ESA/Planck

    This is the first time that scientists have measured these masses using the polarization of the CMB and the novel estimation method.

    “Making this estimate is important because most of the mass of galaxy clusters isn’t even visible – it’s dark matter, which does not emit light but interacts through gravity and makes up about 85% of the matter in our universe,” Benson said.

    The scientists’ work may eventually shed light on dark matter, dark energy and cosmological parameters that reveal more about structure formation in the universe.

    1
    The camera on the South Pole Telescope measures minuscule fluctuations in the polarization of cosmic-microwave-background light across the southern sky. Photo: Jason Gallicchio, University of Chicago

    Destination: Antarctica

    At Amundsen-Scott South Pole Station, support staff and scientists, nicknamed “beakers,” work around the clock to manage the South Pole Telescope. It’s not easy work. Amundsen-Scott South Pole Station is located at the southernmost place on Earth, where the average temperature is minus 47 degrees Celsius and the sun rises and sets only once a year. But the South Pole Telescope, a 10-meter telescope charged with observing the cosmic microwave background, known as the CMB, is more than capable of achieving its scientific goals in this harsh environment.

    The camera on the South Pole Telescope measures minuscule fluctuations in the polarization of CMB light across the southern sky on the order of 1 part in 100 million on average, more sensitive than any other experiment to date.

    “These minuscule variations can be affected by large objects such as galaxy clusters, which act as lenses that create distinctive distortions in our signal,” Benson said.

    The signal Benson and other scientists were looking for was a small-scale ripple around galaxy clusters — an effect called gravitational lensing. You can see a similar effect yourself by looking through the base of a clear wine glass behind which a candle is lit.

    “If you look through the bottom of a wine glass base at a flame, you can see a ring of light. That’s like the effect we would see from a strong gravitational lens,” Benson said.

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    Scientists look for small-scale ripple around galaxy clusters — an effect called gravitational lensing. The lensing is similar to the effect you would see looking through the base of a clear wine glass behind which a candle is lit — a ring of light. Image: Sandbox Studio

    Gravitational Lensing NASA/ESA

    “We are seeing a similar effect here, except the distortion is much weaker and the CMB light is spread out over a much larger area on the sky.”

    There was a problem, however. Scientists estimated they would need to look at around 17,000 galaxy clusters to measure the gravitational lensing effect from the CMB and estimate galaxy cluster masses with any certainty, even using their new mathematical estimator. While the South Pole Telescope provided deeper and more sensitive measurements of the CMB’s polarization than ever before, its library of galaxy locations contained only about 1,000 galaxy clusters.

    Destination: Chile

    To identify more galaxy cluster locations from which to examine the gravitational lensing of CMB light around galaxy clusters, the scientists needed to travel roughly 6,000 kilometers north of the South Pole to the Atacama region of Chile, home to the Cerro Tololo Inter-American Observatory.

    Cerro Tololo Inter-American Observatory on Cerro Tololo in the Coquimbo Region of northern Chile Altitude 2,207 m (7,241 ft)

    The Dark Energy Camera, mounted 2,200 meters above sea level on the 4-meter Blanco telescope at Cerro Tololo, is one of the largest digital cameras in the world. Its 520 megapixels see light from objects originating billions of light-years away and capture them in unprecedented quality. Most importantly, the camera captures the light and locations of the 17,000 galaxy clusters scientists needed to observe gravitational lensing of CMB light by galaxy clusters.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    The scientists identified the locations of these clusters using three years’ worth of data from the Fermilab-led Dark Energy Survey and then put these locations into a computer program that searched for evidence of gravitational lensing by the clusters in the polarization of the CMB. Once evidence was found, they could calculate the masses of the galaxy clusters themselves using their new mathematical estimator.

    Destination: Unspoiled places

    In the current study, the scientists found the average galaxy cluster mass to be around 100 trillion times the mass of our sun, an estimate that agrees with other methods. A substantial fraction of this mass is in the form of dark matter.

    To probe deeper, the scientists plan to perform similar experiments using an upgraded South Pole Telescope camera, SPT-3G, installed in 2017, and a next-generation CMB experiment, CMB-S4, that will offer further improvements in sensitivity and more galaxy clusters to examine.

    CMB-S4 will consist of dedicated telescopes equipped with highly sensitive superconducting cameras operating at the South Pole, the Chilean Atacama plateau and possibly northern-hemisphere sites, allowing researchers to constrain the parameters of inflation, dark energy and the number and masses of neutrinos, and even test general relativity on large scales.

    Anthony Bourdain, a gifted storyteller and food writer, once called Antarctica “the last unspoiled place on Earth … where people come together to explore the art of pure science, looking for something called facts.”

    Scientists go far beyond Antarctica to another unspoiled place, the farthest reaches of our universe, to grapple with fundamental cosmological parameters and the behavior of structure in our universe.

    See the full here.


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    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 10:17 am on December 29, 2019 Permalink | Reply
    Tags: , , CMB - Cosmic Microwave Background, , , , , ,   

    From particlebites: “Dark Photons in Light Places” 

    particlebites bloc

    From particlebites

    December 29, 2019
    Amara McCune

    Title: “Searching for dark photon dark matter in LIGO O1 data”

    Author: Huai-Ke Guo, Keith Riles, Feng-Wei Yang, & Yue Zhao

    Reference: https://www.nature.com/articles/s42005-019-0255-0

    There is very little we know about dark matter save for its existence.

    Fritz Zwicky discovered Dark Matter when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, did most of the work on Dark Matter.

    Fritz Zwicky from http:// palomarskies.blogspot.com

    Coma cluster via NASA/ESA Hubble

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science)


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL)


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu

    The LSST, or Large Synoptic Survey Telescope is to be named the Vera C. Rubin Observatory by an act of the U.S. Congress.

    LSST telescope, The Vera Rubin Survey Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    Dark Matter Research

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background [CMB] hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    CMB per ESA/Planck

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LBNL LZ Dark Matter project at SURF, Lead, SD, USA


    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    Its mass(es), its interactions, even the proposition that it consists of particles at all is mostly up to the creativity of the theorist. For those who don’t turn to modified theories of gravity to explain the gravitational effects on galaxy rotation and clustering that suggest a massive concentration of unseen matter in the universe (among other compelling evidence), there are a few more widely accepted explanations for what dark matter might be. These include weakly-interacting massive particles (WIMPS), primordial black holes, or new particles altogether, such as axions or dark photons.

    In particle physics, this latter category is what’s known as the “hidden sector,” a hypothetical collection of quantum fields and their corresponding particles that are utilized in theorists’ toolboxes to help explain phenomena such as dark matter. In order to test the validity of the hidden sector, several experimental techniques have been concocted to narrow down the vast parameter space of possibilities, which generally consist of three strategies:

    1.Direct detection: Detector experiments look for low-energy recoils of dark matter particle collisions with nuclei, often involving emitted light or phonons.
    2.Indirect detection: These searches focus on potential decay products of dark matter particles, which depends on the theory in question.
    3.Collider production: As the name implies, colliders seek to produce dark matter in order to study its properties. This is reliant on the other two methods for verification.

    The first detection of gravitational waves from a black hole merger in 2015 ushered in a new era of physics, in which the cosmological range of theory-testing is no longer limited to the electromagnetic spectrum.

    MIT /Caltech Advanced aLigo


    VIRGO Gravitational Wave interferometer, near Pisa, Italy

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

    Caltech/MIT Advanced aLigo detector installation Hanford, WA, USA

    VIRGO Gravitational Wave interferometer, near Pisa, Italy

    Gravity is talking. Lisa will listen. Dialogos of Eide

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

    Bringing LIGO (the Laser Interferometer Gravitational-Wave Observatory) to the table, proposals for the indirect detection of dark matter via gravitational waves began to spring up in the literature, with implications for primordial black hole detection or dark matter ensconced in neutron stars. Yet a new proposal, in a paper by Guo et. al., [Scientific Reports-Communication Physics] suggests that direct dark matter detection with gravitational waves may be possible, specifically in the case of dark photons.

    Dark photons are hidden sector particles in the ultralight regime of dark matter candidates. Theorized as the gauge boson of a U(1) gauge group, meaning the particle is a force-carrier akin to the photon of quantum electrodynamics, dark photons either do not couple or very weakly couple to Standard Model particles in various formulations. Unlike a regular photon, dark photons can acquire a mass via the Higgs mechanism. Since dark photons need to be non-relativistic in order to meet cosmological dark matter constraints, we can model them as a coherently oscillating background field: a plane wave with amplitude determined by dark matter energy density and oscillation frequency determined by mass. In the case that dark photons weakly interact with ordinary matter, this means an oscillating force is imparted. This sets LIGO up as a means of direct detection due to the mirror displacement dark photons could induce in LIGO detectors.

    3
    Figure 1: The experimental setup of the Advanced LIGO interferometer. We can see that light leaves the laser and is reflected between a few power recycling mirrors (PR), split by a beam splitter (BS), and bounced between input and end test masses (ITM and ETM). The entire system is mounted on seismically-isolated platforms to reduce noise as much as possible. Source: https://arxiv.org/pdf/1411.4547.pdf

    LIGO consists of a Michelson interferometer, in which a laser shines upon a beam splitter which in turn creates two perpendicular beams. The light from each beam then hits a mirror, is reflected back, and the two beams combine, producing an interference pattern. In the actual LIGO detectors, the beams are reflected back some 280 times (down a 4 km arm length) and are split to be initially out of phase so that the photodiode detector should not detect any light in the absence of a gravitational wave. A key feature of gravitational waves is their polarization, which stretches spacetime in one direction and compresses it in the perpendicular direction in an alternating fashion. This means that when a gravitational wave passes through the detector, the effective length of one of the interferometer arms is reduced while the other is increased, and the photodiode will detect an interference pattern as a result.

    LIGO has been able to reach an incredible sensitivity of one part in 10^{23} in its detectors over a 100 Hz bandwidth, meaning that its instruments can detect mirror displacements up to 1/10,000th the size of a proton. Taking advantage of this number, Guo et. al. demonstrated that the differential strain (the ratio of the relative displacement of the mirrors to the interferometer’s arm length, or h = \Delta L/L) is also sensitive to ultralight dark matter via the modeling process described above. The acceleration induced by the dark photon dark matter on the LIGO mirrors is ultimately proportional to the dark electric field and charge-to-mass ratio of the mirrors themselves.

    Once this signal is approximated, next comes the task of estimating the background. Since the coherence length is of order 10^9 m for a dark photon field oscillating at order 100 Hz, a distance much larger than the separation between the LIGO detectors at Hanford and Livingston (in Washington and Louisiana, respectively), the signals from dark photons at both detectors should be highly correlated. This has the effect of reducing the noise in the overall signal, since the noise in each of the detectors should be statistically independent. The signal-to-noise ratio can then be computed directly using discrete Fourier transforms from segments of data along the total observation time. However, this process of breaking up the data, known as “binning,” means that some signal power is lost and must be corrected for.

    4
    Figure 2: The end result of the Guo et. al. analysis of dark photon-induced mirror displacement in LIGO. Above we can see a plot of the coupling of dark photons to baryons as a function of the dark photon oscillation frequency. We can see that over further Advanced LIGO runs, up to O4-O5, these limits are expected to improve by several orders of magnitude. Source: https://www.nature.com/articles/s42005-019-0255-0

    In applying this analysis to the strain data from the first run of Advanced LIGO, Guo et. al. generated a plot which sets new limits for the coupling of dark photons to baryons as a function of the dark photon oscillation frequency. There are a few key subtleties in this analysis, primarily that there are many potential dark photon models which rely on different gauge groups, yet this framework allows for similar analysis of other dark photon models. With plans for future iterations of gravitational wave detectors, further improved sensitivities, and many more data runs, there seems to be great potential to apply LIGO to direct dark matter detection. It’s exciting to see these instruments in action for discoveries that were not in mind when LIGO was first designed, and I’m looking forward to seeing what we can come up with next!

    Learn More:

    An overview of gravitational waves and dark matter: https://www.symmetrymagazine.org/article/what-gravitational-waves-can-say-about-dark-matter
    A summary of dark photon experiments and results: https://physics.aps.org/articles/v7/115
    Details on the hardware of Advanced LIGO: https://arxiv.org/pdf/1411.4547.pdf
    A similar analysis done by Pierce et. al.: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.121.061102

    See the full article here .

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    What is ParticleBites?

    ParticleBites is an online particle physics journal club written by graduate students and postdocs. Each post presents an interesting paper in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.

    The papers are accessible on the arXiv preprint server. Most of our posts are based on papers from hep-ph (high energy phenomenology) and hep-ex (high energy experiment).

    Why read ParticleBites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. With each brief ParticleBite, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in particle physics.

    Who writes ParticleBites?

    ParticleBites is written and edited by graduate students and postdocs working in high energy physics. Feel free to contact us if you’re interested in applying to write for ParticleBites.

    ParticleBites was founded in 2013 by Flip Tanedo following the Communicating Science (ComSciCon) 2013 workshop.

    2
    Flip Tanedo UCI Chancellor’s ADVANCE postdoctoral scholar in theoretical physics. As of July 2016, I will be an assistant professor of physics at the University of California, Riverside

    It is now organized and directed by Flip and Julia Gonski, with ongoing guidance from Nathan Sanders.

     
  • richardmitnick 10:20 am on December 28, 2019 Permalink | Reply
    Tags: "Astronomers discover what might be the largest known structure in the universe that leaves its imprint on cosmic microwave background radiation", , , , CMB - Cosmic Microwave Background, , U Hawaii IFA at Manua Kea   

    From U Hawaii IFA at Manua Kea: “Astronomers discover what might be the largest known structure in the universe that leaves its imprint on cosmic microwave background radiation” 


    From University of Hawaii

    U Hawaii Institute for Astronomy

    From U Hawaii IFA at Manua Kea

    Synopsis: A very large cold spot that has been a mystery for over a decade can now be explained.

    1
    The Cold Spot area resides in the constellation Eridanus in the southern galactic hemisphere. The insets show the environment of this anomalous patch of the sky as mapped by Szapudi’s team using PS1[below] and WISE data and as observed in the cosmic microwave background [CMB] temperature data taken by the Planck satellite. The angular diameter of the vast supervoid aligned with the Cold Spot, which exceeds 30 degrees, is marked by the white circles. Graphics by Gergő Kránicz. Image credit: ESA Planck Collaboration. High-resolution version (6.6 Mb)

    NASA/WISE NEOWISE Telescope

    ESA/Planck 2009 to 2013

    If the Cold Spot originated from the Big Bang itself, it could be a rare sign of exotic physics that the standard cosmology (basically, the Big Bang theory and related physics) does not explain. If, however, it is caused by a foreground structure between us and the CMB, it would be a sign that there is an extremely rare large-scale structure in the mass distribution of the universe.

    Using data from Hawaii’s Pan-STARRS1 (PS1) [below] telescope located on Haleakala, Maui, and NASA’s Wide Field Survey Explorer (WISE) [above] satellite, Szapudi’s team discovered a large supervoid, a vast region 1.8 billion light-years across, in which the density of galaxies is much lower than usual in the known universe. This void was found by combining observations taken by PS1 at optical wavelengths with observations taken by WISE at infrared wavelengths to estimate the distance to and position of each galaxy in that part of the sky.

    Earlier studies, also done in Hawaii, observed a much smaller area in the direction of the Cold Spot, but they could establish only that no very distant structure is in that part of the sky. Paradoxically, identifying nearby large structures is harder than finding distant ones, since we must map larger portions of the sky to see the closer structures. The large three-dimensional sky maps created from PS1 and WISE by Dr. András Kovács (Eötvös Loránd University, Budapest, Hungary) were thus essential for this study. The supervoid is only about 3 billion light-years away from us, a relatively short distance in the cosmic scheme of things.

    Imagine there is a huge void with very little matter between you (the observer) and the CMB.

    CMB per ESA/Planck

    Now think of the void as a hill. As the light enters the void, it must climb this hill. If the universe were not undergoing accelerating expansion, then the void would not evolve significantly, and light would descend the hill and regain the energy it lost as it exits the void. But with the accelerating expansion, the hill is measurably stretched as the light is traveling over it. By the time the light descends the hill, the hill has gotten flatter than when the light entered, so the light cannot pick up all the energy it lost upon entering the void. The light exits the void with less energy, and therefore at a longer wavelength, which corresponds to a colder temperature.

    Getting through a supervoid can take millions of years, even at the speed of light, so this measurable effect, known as the Integrated Sachs-Wolfe (ISW) effect, might provide the first explanation one of the most significant anomalies found to date in the CMB, first by a NASA satellite called the Wilkinson Microwave Anisotropy Probe (WMAP), and more recently, by Planck [above], a satellite launched by the European Space Agency.

    NASA/WMAP 2001 to 2010

    While the existence of the supervoid and its expected effect on the CMB do not fully explain the Cold Spot, it is very unlikely that the supervoid and the Cold Spot at the same location are a coincidence. The team will continue its work using improved data from PS1 and from the Dark Energy Survey being conducted with a telescope in Chile to study the Cold Spot and supervoid, as well as another large void located near the constellation Draco.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    The study is being published online on April 20 in Monthly Notices of the Royal Astronomical Society by the Oxford University Press. In addition to Szapudi and Kovács, researchers who contributed to this study include UH Manoa alumnus Benjamin Granett (now at the National Institute for Astrophysics, Italy), Zsolt Frei (Eötvös Loránd), and Joseph Silk (Johns Hopkins).

    See the full article here ..

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    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA

    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth.

    Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, 4,207 m (13,802 ft)

    The two, 10-meter optical/infrared telescopes near the summit of Maunakea on the island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrographs and world-leading laser guide star adaptive optics systems.

    Pann-STARS 1 Telescope, U Hawaii, situated at Haleakala Observatories near the summit of Haleakala , on the island of Maui in Hawaii, USA, Pann-STARS 1 Telescope, U Hawaii, situated at Haleakala Observatories near the summit of Haleakala in Hawaii, USA, altitude 3,052 m (10,013 ft)altitude 3,052 m (10,013 ft)


    System Overview

    The University of Hawai‘i includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 9:14 am on December 2, 2019 Permalink | Reply
    Tags: "The Universe's Baby Picture Could Help Us Predict Its Future", , , , CMB - Cosmic Microwave Background, , , ,   

    From Curiosity: “The Universe’s Baby Picture Could Help Us Predict Its Future” 

    Curiosity Makes You Smarter

    From From Curiosity

    September 18, 2018 [Just now in social media]
    Elizabeth Howell

    Look up at the sky and you see stars and galaxies and planets. But way in the background lurks an interesting form of radiation known as the Cosmic Microwave Background [CMB]. That’s the universe’s baby picture, and when we study that picture, we don’t only see its past — we also see its future.

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    What’s Behind the Baby Face?

    Next time you pull out your baby pictures, take a look at the details: what you looked like, who you were with, what you were doing. Often, we can “see” a bit of ourselves today by looking at what we used to be long ago. Our parents, friends, and activities all shaped us into the person we became.

    This concept not only works for people, but it’s also a useful analogy for science. Even our 13.8-billion-year-old universe was a baby in a time long, long ago – just after the universe was formed in an event known as the Big Bang. Shortly after birth, the universe was so hot and so dense that not even light could penetrate the tiny cocoon. Then space expanded rapidly, allowing light to shine through and molecules to come together.

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex Mittelmann Cold creation

    The first stars and galaxies turned on, and just after them came the first planets.

    Funny enough, we can still see evidence of all that activity by using microwaves. Light is in a spectrum; we can see some of it with our eyes, but there are other forms of light, like X-rays and microwaves, that we can’t see except with telescopes or other scientific instruments. Microwaves have extremely long wavelengths, and by using them, we can peer all the way back to the universe’s first few thousand years. Scientists call this “baby picture” the Cosmic Microwave Background, or CMB.

    1
    NASA WMAP

    NASA/WMAP 2001 to 2010

    Later this month, NASA will send a balloon with a science experiment — known as the Primordial Inflation Polarization Explorer (PIPER) — to the edge of our atmosphere.

    3

    There, PIPER will take more baby pictures of the universe. But why do we care in the first place? What’s the use of looking at the radiation of the universe from so long ago, at a time long before the Earth formed? What’s the point?

    Well, for one thing, it will help us understand the universe’s ultimate fate. Maybe we’re going to keep expanding forever, or maybe we’re going to collapse into a huge crunch. We can best understand this by mapping what the universe is made of. A past mission called the Wilkinson Microwave Anisotropy Probe (WMAP) helped scientists come up with some estimates.

    It turns out that 5 percent of the matter in the universe is normal matter, the kind that telescopes can see. The rest (95 percent) is made up of dark energy and dark matter that telescopes can’t sense except through their effects on normal matter, such as the way they bend light.

    Dark energy and dark matter are exotic and we know little about them, but they’re still super important. They make up most of the mass of the universe. They alter the paths of light and of other objects. And by studying dark matter and dark energy, we can understand how fast the universe is expanding and whether the universe will expand forever, which most scientists think is likely.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    Dark Matter Research

    Fritz Zwicky discovered Dark Matter when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, did most of the work on Dark Matter.

    Fritz Zwicky from http:// palomarskies.blogspot.com

    Coma cluster via NASA/ESA Hubble

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science)


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL)


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu

    The LSST, or Large Synoptic Survey Telescope is to be named the Vera C. Rubin Observatory by an act of the U.S. Congress.

    LSST telescope, The Vera Rubin Survey Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LBNL LZ Dark Matter project at SURF, Lead, SD, USA


    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    There’s a lot more you can see peering at the CMB, and NASA has a whole Tumblr page explaining more about our universe’s history and what the PIPER mission will accomplish. So next time you look up at the sky, remember — our universe had a pretty baby face, and we’re only just getting a clear picture of it.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Curiosity Makes You Smarter

    Curiosity is on a mission to make learning easier and more fun than it has ever been. Our goal is to ignite curiosity and inspire people to learn. Each day, we create and curate engaging topics for millions of lifelong learners worldwide.

    Experience Curiosity on our website, through our apps and across social media. We designed Curiosity with your busy life in mind. Our editors find interesting and important topics that you’ll want to know more about, and introduce you to the best ways to keep learning.

    We hope you make Curiosity part of your daily digital diet. Never stop learning!

     
  • richardmitnick 12:10 pm on July 24, 2019 Permalink | Reply
    Tags: , , , CMB - Cosmic Microwave Background, , , , ,   

    From Niels Bohr Institute: “Probing the beginning of the Universe can soon be done more accurately” 

    University of Copenhagen

    Niels Bohr Institute bloc

    From Niels Bohr Institute

    Measurement of the Cosmic Microwave Background radiation:

    In the Karoo desert in South Africa, scientists from all over the world plan to set up a huge array of telescopes – the Square Kilometer Array (SKA).


    SKA South Africa

    As many as 200 telescopes will be erected in the next decade, in order to achieve the highest possible precision in measuring radiation from the Universe.

    1
    Photograph of the SKA-MPG telescope for which the study was performed. The primary dish has a diameter of 15 meters and can receive signals between 1.7 and 3.5 Gigahertz. It is currently being installed in the South African Karoo desert. © South African Radio Astronomy Observatory (SARAO)

    Among the many scientific goals of the SKA are tests of Einstein’s relativity theory, probing the nature of Dark Energy, and studying the properties of our Galaxy, to name just a few. A team of researchers, amongst them Sebastian von Hausegger, who just finished as a PhD fellow in the Theoretical Particle Physics and Cosmology group of the Niels Bohr Institute, University of Copenhagen, has developed a plan to utilize the very first prototype, the SKA-MPG telescope, in the Karoo in a different way in the near future: the additional knowledge about our Galaxy which this telescope will bring can be used immediately for the study of the Cosmic Microwave Background (CMB), the earliest picture of our Universe. In a detailed study, they investigate the scientific potential of the SKA-MPG telescope – the prototype for those dishes which eventually should be built into the array is built by the German Max Planck Society – and demonstrate the huge advantage already this single dish will have for cosmology. This forecast was led by Aritra Basu from Bielefeld University and is now published in Monthly Notices of the Royal Astronomical Society.

    Separating the foreground from the background

    The Cosmic Microwave Background radiation (CMB) is the afterglow of the forming of our Universe.

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    In this respect, it carries the fingerprint of how everything we know and are came to be. If analyzed correctly, it will tell us about the very early universe, perhaps including stories about gravitational waves generated by a process called inflation, the currently leading theory of the Universe’s beginning – obviously, we want to be able to study it as closely and accurately as possible.

    Inflation

    4
    Alan Guth, from Highland Park High School and M.I.T., who first proposed cosmic inflation

    HPHS Owls

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation

    Alan Guth’s notes:

    Alan Guth’s original notes on inflation

    However, all measurements we attempt to take of the CMB are disturbed by the radiation emitted by our own Galaxy. This radiation is called `foreground emission’ in the CMB community, to distinguish it from the sought-for cosmic `background’. To reliably remove thisforeground, we must understand exactly what it is, and what is causing it. This is where telescopes like the one shown come into play.

    Sebastian von Hausegger’s work as a PhD student dealt with the problem of foreground separation. “Essentially, you take a picture of the sky at different frequencies, and by tracing the differences of those pictures, you understand what sort of foreground emission they contain. Once that is done properly, the real work with interpreting the background can begin”, Sebastian explains. “The more frequencies you take pictures at – the better your understanding gets of the physical processes, the structure, and the composition of the Milky Way!” The SKA-MPG telescope is able to measure at 2048 different frequencies between 1.7 and 3.5 GHz – many more than previously possible.

    Bringing the radio astronomy and the CMB community together

    Sebastian continues, “The radio emission of our Galaxy is mainly caused by electrons, zooming around in the Galactic disk, and they can do crazy things. As a part of my PhD, I visited the Astroparticle Physics and Cosmology group at Bielefeld University, Germany. The group includes experts on galactic radio emission – the emission we call foreground radiation. I visited them as a representative from the CMB research community, so to say. Our own Galaxy is not that interesting in the grand scale of things, but the insight gained from measurements of its emission can sure help us learn about this grand scale! In this collaboration,we tried to bring the two communities closer together.”

    Motivated by the properties of the telescope, the authors of this study consider a much more ambitious model for the radio-foregrounds than was done in previous efforts. Even considering the impact of the SKA-MPG prototype alone, the level of achievable detail is much higher than with current data and the inferred prospects for CMB analyses are highly promising.

    An array of up to 200 telescopes is the goal

    The ambition of the Square Kilometer Array is to finally place 200 telescopes in the South African desert. The reason for choosing a remote area like a desert for performing their measurements the restriction of radio emission in the surroundings(the Karoo desert has been made a so-called Radio Quiet Zone). The large number of telescopes will give the SKA unprecedented precision. “As we speak, the prototype telescope is being built, and is expected to be completed in the autumn. It will be very interesting to see what the data will tell us, once it is up – not to mention the future data of the entire array”, says Sebastian.

    See the full article here .


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


    Stem Education Coalition

    Niels Bohr Institute Campus

    Niels Bohr Institute (Danish: Niels Bohr Institutet) is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

    The Institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institute.[1] Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.[2]

    During the 1920s, and 1930s, the Institute was the center of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

    On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institute.

    The University of Copenhagen (UCPH) (Danish: Københavns Universitet) is the oldest university and research institution in Denmark. Founded in 1479 as a studium generale, it is the second oldest institution for higher education in Scandinavia after Uppsala University (1477). The university has 23,473 undergraduate students, 17,398 postgraduate students, 2,968 doctoral students and over 9,000 employees. The university has four campuses located in and around Copenhagen, with the headquarters located in central Copenhagen. Most courses are taught in Danish; however, many courses are also offered in English and a few in German. The university has several thousands of foreign students, about half of whom come from Nordic countries.

    The university is a member of the International Alliance of Research Universities (IARU), along with University of Cambridge, Yale University, The Australian National University, and UC Berkeley, amongst others. The 2016 Academic Ranking of World Universities ranks the University of Copenhagen as the best university in Scandinavia and 30th in the world, the 2016-2017 Times Higher Education World University Rankings as 120th in the world, and the 2016-2017 QS World University Rankings as 68th in the world. The university has had 9 alumni become Nobel laureates and has produced one Turing Award recipient

     
  • richardmitnick 10:42 am on June 14, 2019 Permalink | Reply
    Tags: Astromomy Magazine, , , , CMB - Cosmic Microwave Background,   

    From Astronomy Magazine: “The mystery of cosmic cold spots just got even weirder” 

    Astronomy magazine

    From Astronomy Magazine

    June 06, 2019
    Korey Haynes

    1
    Recent analysis of Planck data upholds mysteries that have existed since the spacecraft’s first results in 2013. ESA/Planck Collaboration

    During its time in orbit, the European Space Agency’s Planck spacecraft gave humanity the most sophisticated measurements ever made of the cosmic microwave background (CMB) radiation, the first flash of light that rippled across the universe after the Big Bang. Plank told us the shape of the universe and confirmed crucial components of the Big Bang as it collected data between 2009 and 2013. It did all that by measuring the intensity of the CMB across the sky. And since then astronomers have kept putting out new maps of the cosmos as they mine data and discover new ways to tease out secrets.

    While Planck’s measurements in large part confirmed physicists’ understanding of the universe, some of the most interesting things Planck discovered were the unexpected details. For one, the universe seems divided into two hemispheres, one hot and one cold. And the hot hemisphere also contains a stark cold spot. Neither of these details were predicted, and shouldn’t in fact exist, according to the so-called standard cosmological model, which otherwise well describes the universe as viewed by Planck. The third surprise is the very slight way Planck’s measurements stray from the standard model, only at large scales. While earlier spacecraft had hinted at all these issues, Planck confirmed them for scientists, bringing into high resolution a problem many researchers had hoped would instead fade away with increased precision.

    Now, scientists have compared Planck’s map of those temperature anomalies – where space itself is just slightly warmer or cooler than the average of just above absolute zero – to a map of the sky’s polarization. This second map holds a record of how the light scattered across the sky just 380,000 years after the Big Bang. Researchers hoped the polarization map could answer questions about the meaning of the anomalies they’d been watching in the temperature maps by either strongly echoing them or not showing them at all. But the polarization map shows either no or faint evidence of the anomalies, leaving scientists still wondering – are the signals saying something important about the makeup of our universe? Or are they merely random fluctuations in space, signifying nothing at all?

    Mapping cosmic differences

    In the temperature maps, researchers had noted suspicious anomalies that show up at large scales – some 10 times bigger than the full Moon on the sky. These temperature variations don’t match with standard explanations of the universe’s physics as we know it. Scientists have also proven that the features are not due to observing quirks of their telescope. They are, however, just faint enough that these cold spots could possibly be random – while also being just strong enough that scientists can’t quite ignore them.

    Their appearance hints that something about the standard cosmological model isn’t quite right.

    Because the polarization map is a largely independent measurement of the sky (though taken with the same spacecraft), scientists hoped it could shed light on whether the anomalies were a true signal of something previously unknown about the universe, or simply a random fluctuation.

    Unfortunately, when they compared the most advanced maps that Planck has produced, they found only faint evidence of the anomalies. That is, the spots appear, but not in a statistically significant way. Researchers from across the Planck Collaboration published their results in the journal Astronomy and Astrophysics on Thursday.

    This leaves scientists stuck with two possibilities. The first is that the anomalies are simply flukes of statistics – stronger than suggested by physics, but still just random, the way coin flips don’t always turn up exactly 50/50, even after 1,000 tries.

    The other possibility is some kind of new physics not currently explained by the standard model. That option is less likely now, given the polarization maps didn’t show the anomalies very clearly. But they do show faint signs of the signals, and because scientists don’t know what this new physics might be, there’s no way for them to know if it should show up in both polarization and temperature maps.

    2
    The anomalies in the cosmic microwave background have been, and remain, a thorn in the side of the standard cosmological model. The standard model encompasses the area in green, while Planck’s data appears as red points with error bars. For small scales (the right side of the graph) the two match quite well, while there is less agreement – but also more uncertainty – at large scales. ESA/Planck Collaboration

    Planck isn’t taking new data, and scientists have probably produced the most detailed maps they can from the available information. While clever ideas might yet emerge, solving this mystery with new information will likely have to wait another decade or more, until a new generation of CMB-spying spacecraft take to the skies.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 8:43 am on May 9, 2019 Permalink | Reply
    Tags: "A New Filter to Better Map the Dark Universe", , , “Lensing can magnify or demagnify things. It also distorts them along a certain axis so they are stretched in one direction.”, , CMB - Cosmic Microwave Background, , , , The researchers found that a certain lensing signature called shearing seems largely immune to the foreground “noise” effects that otherwise interfere with the CMB lensing data.,   

    From Lawrence Berkeley National Lab: “A New Filter to Better Map the Dark Universe” 

    Berkeley Logo

    From Lawrence Berkeley National Lab

    May 8, 2019
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    1
    Just as a wine glass distorts an image, showing temperature fluctuations in the cosmic microwave background [CMB] in this photo illustration, large objects like galaxy clusters and galaxies can similarly distort this light to produce lensing effects. (Credit: Emmanuel Schaan and Simone Ferraro/Berkeley Lab)

    The earliest known light in our universe, known as the cosmic microwave background [CMB], was emitted about 380,000 years after the Big Bang.

    CMB per ESA/Planck


    ESA/Planck 2009 to 2013

    The patterning of this relic light holds many important clues to the development and distribution of large-scale structures such as galaxies and galaxy clusters.

    Gravitational Lensing NASA/ESA

    Distortions in the cosmic microwave background (CMB), caused by a phenomenon known as lensing, can further illuminate the structure of the universe and can even tell us things about the mysterious, unseen universe – including dark energy, which makes up about 68 percent of the universe and accounts for its accelerating expansion, and dark matter, which accounts for about 27 percent of the universe.

    Set a stemmed wine glass on a surface, and you can see how lensing effects can simultaneously magnify, squeeze, and stretch the view of the surface beneath it. In lensing of the CMB, gravity effects from large objects like galaxies and galaxy clusters bend the CMB light in different ways. These lensing effects can be subtle (known as weak lensing) for distant and small galaxies, and computer programs can identify them because they disrupt the regular CMB patterning.

    Weak gravitational lensing NASA/ESA Hubble

    There are some known issues with the accuracy of lensing measurements, though, and particularly with temperature-based measurements of the CMB and associated lensing effects.

    While lensing can be a powerful tool for studying the invisible universe, and could even potentially help us sort out the properties of ghostly subatomic particles like neutrinos, the universe is an inherently messy place.

    And like bugs on a car’s windshield during a long drive, the gas and dust swirling in other galaxies, among other factors, can obscure our view and lead to faulty readings of the CMB lensing.

    There are some filtering tools that help researchers to limit or mask some of these effects, but these known obstructions continue to be a major problem in the many studies that rely on temperature-based measurements.

    The effects of this interference with temperature-based CMB studies can lead to erroneous lensing measurements, said Emmanuel Schaan, a postdoctoral researcher and Owen Chamberlain Postdoctoral Fellow in the Physics Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

    “You can be wrong and not know it,” Schaan said. “The existing methods don’t work perfectly – they are really limiting.”

    To address this problem, Schaan teamed up with Simone Ferraro, a Divisional Fellow in Berkeley Lab’s Physics Division, to develop a way to improve the clarity and accuracy of CMB lensing measurements by separately accounting for different types of lensing effects.

    “Lensing can magnify or demagnify things. It also distorts them along a certain axis so they are stretched in one direction,” Schaan said.

    The researchers found that a certain lensing signature called shearing, which causes this stretching in one direction, seems largely immune to the foreground “noise” effects that otherwise interfere with the CMB lensing data. The lensing effect known as magnification, meanwhile, is prone to errors introduced by foreground noise. Their study, published May 8 in the journal Physical Review Letters, notes a “dramatic reduction” in this error margin when focusing solely on shearing effects.

    3
    A set of cosmic microwave background images with no lensing effects (top row) and with exaggerated cosmic microwave background lensing effects (bottom row). (Credit: Wayne Hu and Takemi Okamoto/University of Chicago)

    The sources of the lensing, which are large objects that stand between us and the CMB light, are typically galaxy groups and clusters that have a roughly spherical profile in temperature maps, Ferraro noted, and the latest study found that the emission of various forms of light from these “foreground” objects only appears to mimic the magnification effects in lensing but not the shear effects.

    “So we said, ‘Let’s rely only on the shear and we’ll be immune to foreground effects,’” Ferraro said. “When you have many of these galaxies that are mostly spherical, and you average them, they only contaminate the magnification part of the measurement. For shear, all of the errors are basically gone.”

    He added, “It reduces the noise, allowing us to get better maps. And we’re more certain that these maps are correct,” even when the measurements involve very distant galaxies as foreground lensing objects.

    The new method could benefit a range of sky-surveying experiments, the study notes, including the POLARBEAR-2 and Simons Array experiments, which have Berkeley Lab and UC Berkeley participants; the Advanced Atacama Cosmology Telescope (AdvACT) project; and the South Pole Telescope – 3G camera (SPT-3G). It could also aid the Simons Observatory and the proposed next-generation, multilocation CMB experiment known as CMB-S4 – Berkeley Lab scientists are involved in the planning for both of these efforts.

    POLARBEAR McGill Telescope located in the Atacama Desert of northern Chile in the Antofagasta Region. The POLARBEAR experiment is mounted on the Huan Tran Telescope (HTT) at the James Ax Observatory in the Chajnantor Science Reserve.

    LBL The Simons Array in the Atacama in Chile, with the 6 meter Atacama Cosmology Telescope

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago, the University of California, Berkeley, Case Western Reserve University, Harvard/Smithsonian Astrophysical Observatory, the University of Colorado Boulder, McGill University, The University of Illinois at Urbana-Champaign, University of California, Davis, Ludwig Maximilian University of Munich, Argonne National Laboratory, and the National Institute for Standards and Technology. It is funded by the National Science Foundation.

    South Pole Telescope SPT-3G Camera

    The method could also enhance the science yield from future galaxy surveys like the Berkeley Lab-led Dark Energy Spectroscopic Instrument (DESI) project under construction near Tucson, Arizona, and the Large Synoptic Survey Telescope (LSST) project under construction in Chile, through joint analyses of data from these sky surveys and the CMB lensing data.

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory starting in 2018


    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)


    Kitt Peak National Observatory of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft)

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.


    LSST Data Journey, Illustration by Sandbox Studio, Chicago with Ana Kova

    Increasingly large datasets from astrophysics experiments have led to more coordination in comparing data across experiments to provide more meaningful results. “These days, the synergies between CMB and galaxy surveys are a big deal,” Ferraro said.

    4
    These images show different types of emissions that can interfere with CMB lensing measurements, as simulated by Neelima Sehgal and collaborators. From left to right: The cosmic infrared background, composed of intergalactic dust; radio point sources, or radio emission from other galaxies; the kinematic Sunyaev-Zel’dovich effect, a product of gas in other galaxies; and the thermal Sunyaev-Zel’dovich effect, which also relates to gas in other galaxies. (Credit: Emmanuel Schaan and Simone Ferraro/Berkeley Lab)

    In this study, researchers relied on simulated full-sky CMB data. They used resources at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC) to test their method on each of the four different foreground sources of noise, which include infrared, radiofrequency, thermal, and electron-interaction effects that can contaminate CMB lensing measurements.

    NERSC

    NERSC Cray Cori II supercomputer at NERSC at LBNL, named after Gerty Cori, the first American woman to win a Nobel Prize in science

    NERSC Hopper Cray XE6 supercomputer


    LBL NERSC Cray XC30 Edison supercomputer


    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

    NERSC PDSF


    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    Future:

    Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supeercomputer

    The study notes that cosmic infrared background noise, and noise from the interaction of CMB light particles (photons) with high-energy electrons have been the most problematic sources to address using standard filtering tools in CMB measurements. Some existing and future CMB experiments seek to lessen these effects by taking precise measurements of the polarization, or orientation, of the CMB light signature rather than its temperature.

    “We couldn’t have done this project without a computing cluster like NERSC,” Schaan said. NERSC has also proved useful in serving up other universe simulations to help prepare for upcoming experiments like DESI (see related article).

    The method developed by Schaan and Ferraro is already being implemented in the analysis of current experiments’ data. One possible application is to develop more detailed visualizations of dark matter filaments and nodes that appear to connect matter in the universe via a complex and changing cosmic web.

    The researchers reported a positive reception to their newly introduced method.

    “This was an outstanding problem that many people had thought about,” Ferraro said. “We’re happy to find elegant solutions.”

    NERSC is a DOE Office of Science User Facility.

    See the full article here .

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    Please help promote STEM in your local schools.

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    Bringing Science Solutions to the World

    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

    Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

    A U.S. Department of Energy National Laboratory Operated by the University of California.

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  • richardmitnick 11:18 am on May 7, 2019 Permalink | Reply
    Tags: "A universe is born", , , , CMB - Cosmic Microwave Background, , , , , , , , , The Planck epoch   

    From Symmetry: “A universe is born” 

    Symmetry Mag
    From Symmetry

    05/07/19
    Diana Kwon

    Take a (brief) journey through the early history of our cosmos.

    Timeline of the Inflationary Universe WMAP

    The universe was a busy place during the first three minutes. The cosmos we see today expanded from a tiny speck to much closer to its current massive size; the elementary particles appeared; and protons and neutrons combined into the first nuclei, filling the universe with the precursors of elements.

    By developing clever theories and conducting experiments with particle colliders, telescopes and satellites, physicists have been able to wind the film of the universe back billions of years—and glimpse the details of the very first moments in the history of our cosmic home.

    Take an abridged tour through this history:

    The Planck epoch
    Time: < 10^-43 seconds

    The Planck Epoch https:// http://www.slideshare.net ericgolob the-big-bang-10535251

    Welcome to the Planck epoch, named after the smallest scale of measurements possible in particle physics today. This is currently the closet scientists can get to the beginning of time.

    Theoretical physicists don’t know much about the earliest moments of the universe. After the Big Bang theory gained popularity, scientists thought that in the first moments, the cosmos was at its hottest and densest and that all four fundamental forces—electromagnetic, weak, strong and gravitational—were combined into a single, unified force. But the current leading theoretical framework for our universe’s beginning doesn’t necessarily require these conditions.

    The universe expands
    Time: From 10^-43 seconds to about 10^-36 seconds

    In this stage, which began either at Planck time or shortly after it, scientists think the universe underwent superfast, exponential expansion in a process known as inflation.

    Inflation

    4
    Alan Guth, from Highland Park High School and M.I.T., who first proposed cosmic inflation

    HPHS Owls

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation

    Alan Guth’s notes:
    5

    Physicists first proposed the theory of inflation in the 1980s to address the shortcomings of the Big Bang theory, which, despite its popularity, could not explain why the universe was so flat and uniform, and why its different parts began expanding simultaneously.

    During inflation, quantum fluctuations could have stretched out to produce a pattern that later determined the locations of galaxies. It might have been only after this period of inflation the universe became a hot, dense fireball as described in the Big Bang theory.

    The elementary particles are born
    Time: ~10^-36 seconds

    When the universe was still very hot, the cosmos was like a gigantic accelerator, much more powerful than the Large Hadron Collider, running at extremely high energies. In it, the elementary particles we know today were born.

    Scientists think that first came exotic particles, followed by more familiar ones, such as electrons, neutrinos and quarks. It could be that dark matter particles came about during this time.

    3
    Quarks APS/Alan Stonebraker

    The quarks soon combined, forming the familiar protons and neutrons, which are collectively known as baryons. Neutrinos were able to escape this plasma of charged particles and began traveling freely through space, while photons continued to be trapped by the plasma.

    Standard Model of Particle Physics

    The first nuclei emerge
    Time: ~1 second to 3 minutes

    Scientists think that when the universe cooled enough for violent collisions to subside, protons and neutrons clumped together into nuclei of the light elements—hydrogen, helium and lithium—in a process known as Big Bang nucleosynthesis.

    Protons are more stable than neutrons, due to their lower mass. In fact, a free neutron decays with a 15-minute half-life, while protons may not decay at all, as far as we know.

    So as the particles combined, many protons remained unpaired. As a result, hydrogen—protons that never found a partner—make up around 74% of the mass of “normal” matter in our cosmos. The second most abundant element is helium, which makes up approximately 24%, followed by trace amounts of deuterium, lithium, and helium-3 (helium with a three-baryon core).

    Periodic table Sept 2017. Wikipedia

    Scientists have been able to accurately measure the density of baryons in our universe. Most of those measurements line up with theorists’ estimations of what the quantities ought to be, but there is one lingering issue: Lithium calculations are off by a factor of three. It could be that the measurements are off, but it could also be that something we don’t yet know about happened during this time period to change the abundance of lithium.

    The cosmic microwave background becomes visible
    Time: 380,000 years

    Hundreds of thousands of years after inflation, the particle soup had cooled enough for electrons to bind to nuclei to form electrically neutral atoms. Through this process, which is also known as recombination, photons became free to traverse the universe, creating the cosmic microwave background.

    CMB per ESA/Planck


    ESA/Planck 2009 to 2013

    Today, the CMB is one of the most valuable tools for cosmologists, who probe its depths in search of answers for many of the universe’s lingering secrets, including the nature of inflation and the cause of matter-antimatter asymmetry.

    Shortly after the CMB became detectable, neutral hydrogen particles formed into a gas that filled the universe. Without any objects emitting high-energy photons, the cosmos was plunged into the dark ages for millions of years.

    Dark Energy Camera Enables Astronomers a Glimpse at the Cosmic Dawn. CREDIT National Astronomical Observatory of Japan

    The earliest stars shine
    Time: ~100 million years

    The dark ages ended with the formation of the first stars and the occurrence of reionization, a process through which highly energetic photons stripped electrons off neutral hydrogen atoms.

    Reionization era and first stars, Caltech

    Scientists think that the vast majority of the ionizing photons emerged from the earliest stars. But other processes, such as collisions between dark matter particles, may have also played a role.

    At this time, matter began to form the first galaxies. Our own galaxy, the Milky Way, contains stars that were born when the universe was only several hundred million years old.

    Milky Way NASA/JPL-Caltech /ESO R. Hurt

    Our sun is born
    Time: 9.2 billion years

    3
    NASA

    The sun is one of a few hundred billion stars in the Milky Way. Scientists think it formed from a giant cloud of gas that consisted mostly hydrogen and helium.

    Today
    Time: 13.8 billion years

    Today, our cosmos sits at a cool 2.7 Kelvin (minus 270.42 degrees Celsius). The universe is expanding at an increasing rate, in a manner similar to (but many orders of magnitude slower than) inflation.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Physicists think that dark energy—a mysterious repulsive force that currently accounts for about 70% of the energy in our universe—is most likely driving that accelerated expansion.

    Dark energy depiction. Image: Volker Springle/Max Planck Institute for Astrophysics/SP)

    See the full article here .


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

    Please help promote STEM in your local schools.


    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 10:41 am on October 14, 2018 Permalink | Reply
    Tags: , , , CMB - Cosmic Microwave Background, , , The Jesuit Astronomer Who Conceived of the Big Bang   

    From Discover Magazine: “The Jesuit Astronomer Who Conceived of the Big Bang” 

    DiscoverMag

    From Discover Magazine

    October 12, 2018
    Korey Haynes

    1
    All of the galaxies we see in the distant universe are speeding away from us. This clue led Lemaitre to the idea of an expanding universe: the Big Bang. Credit: NASA/ESA/H. Teplitz and M. Rafelski (IPAC/Caltech)/A. Koekemoer (STScI)/R. Windhorst (Arizona State University)/Z. Levay (STScI)

    NASA/ESA Hubble Telescope

    In 1927, a prescient astronomer named Georges Lemaître looked at data showing how galaxies move. He noticed something peculiar – all of them appeared to be speeding away from Earth. Not only that, but the farther away they were, the faster they went. He determined a mathematical way to represent this, and connected his relationship to Einstein’s law of General Relativity to produce a grand idea: That of a universe continually expanding. It was a radical idea then, but today it fits with our conception of a universe spawned by a Big Bang.

    Inflationary Universe. NASA/WMAP

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    If you’re an astronomy trivia buff, the name associated with the Big Bang is Edwin Hubble, who also has a rather famous telescope named after himself. Hubble also came up with the concept, but Lemaître beat him to the punch, though his idea got little attention at the time. Now, he may finally share in the recognition for his revolutionary theory.

    Edwin Hubble at Caltech Palomar Samuel Oschin 48 inch Telescope, (credit: Emilio Segre Visual Archives/AIP/SPL)

    It’s too late to rename the Hubble Space Telescope, which is in its twilight years of use anyway. But astronomers are considering renaming the law that explains how the universe expands, from the Hubble Law to the Hubble-Lemaître Law.

    The matter was brought to a vote in August at a meeting of the International Astronomical Union in Vienna, Austria. This is the same body that decided by a vote in 2006 to demote Pluto from planet to dwarf planet. It’s a decision that still stings for some people, both astronomers and members of the public alike. It’s especially contentious because the vote only included the astronomers who were physically present at the 2006 meeting – a tiny fraction of all IAU members. Seeking to avoid the same ruffled feathers, the IAU is taking a different tack this time. Instead of making a final decision at the meeting, attending members took a straw poll to see if there was widespread interest in the change. There was.

    Now all 13,000-plus members of the IAU will get to have their say in the form of an electronic vote before the end of the year. So who is this priest-scientist they’re considering honoring with a foundational cosmological law?

    2
    Georges Lemaitre was a Catholic priest who was the first to describe the expanding universe. Credit: Courtesy of the Catholic University of Louven

    Georges Lemaître: Soldier, Scientist, Priest

    Georges Lemaître was born in Belgium. He volunteered for service in the First World War, interrupting his engineering studies to do so, and earned a medal for his service. Afterwards, he plunged back into academia, this time in physics and math, and began studies to be a priest at the same time. He earned his PhD in 1920, and was ordained in 1923.

    To some in this increasingly polarized age, it might seem odd for a man to be a soldier and a scientist, a religious and scientific devotee in equal measure. But to Lemaître, it seemed to form a coherent whole. He saw his faith and his research as separate enterprises, which neither conflicted nor aided each other. They were simply parallel explorations of the cosmos, both equally worthy of study and contemplation.

    After he published his theory of an expanding universe, and after Hubble published his, Lemaître continued his ideas, building heavily on Einstein’s mathematically-dense framework. He followed the idea of an expanding universe backwards to a logical conclusion. In 1931, he began discussing his “Primeval Atom Hypothesis,” which stated that the universe began as a single point and has been expanding ever since. He also called it the “Cosmic Egg.”

    Modern audiences will recognize this as an early version of the Big Bang Theory, which sometimes finds itself under attack from those who prefer a divine creation story. But Lemaître faced most of his criticism from fellow scientists, who objected to his theory in large part because it sounded too religious. The idea of a universe that had a beginning flew in the face of the scientific consensus of the time, which preferred a static, unchanging universe.

    But Lemaître’s idea was based on a purely physical argument. Eventually the scientific community came around, and discovered strong evidence for what came to be called the Big Bang. That evidence even includes “fossil radiation,” which Lemaître posited might appear as cosmic rays, but which astronomers eventually discovered as the cosmic microwave background [CMB] radiation.

    Cosmic Background Radiation per Planck

    COBE/CMB

    .

    NASA/COBE 1989 to 1993.

    CMB per NASA/WMAP

    NASA/WMAP 2001 to 2010

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    The Church Weighs In

    It’s worth noting that the pope in Lemaître’s time, Pius XII, was delighted that a Catholic priest had conceived of a scientifically valid “creation” story for the universe. It’s also possible, reading between the lines, that the Church was feeling some guilt about the whole Galileo debacle, and looking to clear their conscience. Lemaître himself was less than pleased by the pope butting in, as he viewed his scientific pursuits as completely separate from his religious views, and didn’t appreciate the pope muddying the waters. His Holiness was persuaded to simmer down, but the Catholic Church remains officially in agreement with the Big Bang Theory, and Lemaître retained his good standing in the Church until his death.

    But so what if Lemaître was an interesting person? The scientific law has been known as Hubble’s Law for decades now. And if we change this, doesn’t that open the door to changing names of all sorts of things? And what does it matter, if the underlying science remains unchanged?

    All valid points. But if science is about anything, it’s about revealing the truth. And the truth is that Lemaître arrived at the discovery first. Doesn’t he therefore deserve the credit?

    Then again, Lemaître himself never contested Hubble’s acclaim. He seemed content to let the science speak for itself, whatever it was called.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
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