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  • richardmitnick 10:54 am on January 4, 2017 Permalink | Reply
    Tags: Blue Ring Around an Ancient Red Core, Daily Galaxy, Exotic Double-Ring Galaxy Unlike Any Observed Before,   

    From U Minnesota via Daily Galaxy: “Exotic Double-Ring Galaxy Unlike Any Observed Before –“Blue Ring Around an Ancient Red Core” 

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    University of Minnesota

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    Daily Galaxy

    January 04, 2017
    No writer credit

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    Image credit: Ryan Beauchemin

    Approximately 359 million light-years away from Earth, there is a galaxy with an innocuous name (PGC 1000714) that doesn’t look quite like anything astronomers have observed before. New research provides a first description of a well-defined elliptical-like core surrounded by two circular rings — a galaxy that appears to belong to a class of rarely observed, Hoag-type galaxies (Hoag’s Bull’s Eye Galaxy 600 million light years away is shown above).
    “Less than 0.1% of all observed galaxies are Hoag-type galaxies,” says Burcin Mutlu-Pakdil, lead author of a paper on this work and a graduate student at the Minnesota Institute for Astrophysics, University of Minnesota Twin Cities and University of Minnesota Duluth. Hoag-type galaxies are round cores surrounded by a circular ring, with nothing visibly connecting them. The majority of observed galaxies are disc-shaped like our own Milky Way. Galaxies with unusual appearances give astronomers unique insights into how galaxies are formed and change.

    The researchers collected multi-waveband images of the galaxy, which is only easily observable in the Southern Hemisphere, using a large diameter telescope in the Chilean mountains. These images were used to determine the ages of the two main features of the galaxy, the outer ring and the central body.

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    While the researchers found a blue and young (0.13 billion years) outer ring, surrounding a red and older (5.5 billion years) central core, they were surprised to uncover evidence for second inner ring around the central body. To document this second ring, researchers took their images and subtracted out a model of the core. This allowed them to observe and measure the obscured, second inner ring structure.

    “We’ve observed galaxies with a blue ring around a central red body before, the most well-known of these is Hoag’s object. However, the unique feature of this galaxy is what appears to be an older diffuse red inner ring,” says Patrick Treuthardt, co-author of the study and an astrophysicist at the North Carolina Museum of Natural Sciences.

    Galaxy rings are regions where stars have formed from colliding gas. “The different colors of the inner and outer ring suggest that this galaxy has experienced two different formation periods,” Mutlu-Pakdil says. “From these initial single snapshots in time, it’s impossible to know how the rings of this particular galaxy were formed.” The researchers say that by accumulating snapshot views of other galaxies like this one astronomers can begin to understand how unusual galaxies are formed and evolve.

    While galaxy shapes can be the product of internal or external environmental interactions, the authors speculate that the outer ring may be the result of this galaxy incorporating portions of a once nearby gas-rich dwarf galaxy. They also say that inferring the history of the older inner ring would require the collection of higher-resolution infrared data.

    “Whenever we find a unique or strange object to study, it challenges our current theories and assumptions about how the Universe works. It usually tells us that we still have a lot to learn,” says Treuthardt.

    See the full article here .

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  • richardmitnick 6:59 am on June 21, 2016 Permalink | Reply
    Tags: , , Daily Galaxy, Dim, Tiny M-Dwarf Stars --'Surprisingly Habitable Worlds?'   

    From Daily Galaxy: “Dim, Tiny M-Dwarf Stars –‘Surprisingly Habitable Worlds?’ “ 

    Daily Galaxy
    The Daily Galaxy

    June 20, 2016
    No writer credit found

    1
    Artist’s conception of a red dwarf, the most common type of star in the Sun’s stellar neighborhood, and in the universe. Although termed a red dwarf, the surface temperature of this star would give it an orange hue when viewed from close proximity. NASA Wikipedia

    When you look up at the night sky, none of the stars you see are M dwarfs. These diminutive stars, much smaller and dimmer than our own sun aren’t bright enough to see with the naked eye. Yet M dwarfs (also known as red dwarfs) are by far the most common stars around, comprising some 70 percent of all the stars in the Milky Way. Historically, scientists interested in the search for extrasolar life have shied away from studying M dwarfs. Because they put out much relatively paltry amounts of light and heat, compared to the sun, the general feeling among scientists was that they were unlikely to host habitable planets. But, there’s been a recent shift in habitable planet search strategy .

    A better understanding of habitable zones around M-dwarfs needs to come quickly because of upcoming missions in exoplanet research,” says Ravi Kumar Kopparapu, an assistant research scientist at the NASA Goddard Space Flight Center. NASA’s Transiting Exoplanet Survey Satellite (TESS) is scheduled to launch next year to observe more planets and to serve as a guidepost for NASA’s James Webb Space Telescope in 2018.

    NASA/TESS
    NASA/TESS

    NASA/ESA/CSA Webb Telescope annotated
    NASA/ESA/CSA Webb Telescope annotated

    James Webb can provide higher resolution data that can tell us about what kind of gases are present in the atmosphere of a planet orbiting an M-dwarf star. This data can bring out details such as a planet’s temperature, revealing the potential for the right conditions to exist for life.

    Yet, an M-dwarf’s habitable zone is poorly understood. It is not clear how far away the planets need to be orbiting from the star for surface liquid water to be possible. Because planets in this range orbit so close to an M-dwarf they may be tidally locked, said Ravi Kumar Kopparapu, an assistant research scientist at the NASA Goddard Space Flight Center in Maryland.

    “They’re always facing the same side of the star, just like the Moon does around the Earth,” he said.

    This position could potentially stabilize the climate for life, but on the other hand, the side facing the star might be very hot while the side facing away is very cold.

    A paper based on Kopparapu’s research, The inner edge of the habitable zone for synchronously rotating planets around low-mass stars using general circulation models, was recently published in The Astrophysical Journal.

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    The estimated habitable zones of A stars, G stars and M stars are compared in this diagram. More refinement is needed to better understand the size of these zones. Credit: NASA

    Kopparapu previously came up with a one-dimensional climate model of habitable zones around all stars, including M-dwarfs. This model did not take into account tidal locking around the star, but instead found two types of habitability limits. The first is a moist greenhouse limit, where a planet that is close enough to a star would have water vapor dominated atmosphere rendering the planet uninhabitable due to high temperatures. The second limit is a runaway greenhouse effect, where the energy from the star is so intense (higher than the energy absorbed in the moist greenhouse limit) that it causes oceans to evaporate.

    The new model, explained in the most recent paper, simulates a water-rich planet (roughly Earth’s size). Previous research using this same model found that the climate of such a planet would depend on atmospheric circulation, which in turn depends on the Coriolis force (created by the planet’s rotation). In slowly rotating planets near the inner edge of the habitable zone, the Coriolis force is weak, the clouds stay fairly stationary, and the planet has lower temperatures than predicted by one-dimensional models because the clouds reflect the light of the star. This results in the habitable zone being much closer to the star to take into account this cooling effect.

    Kopparapu’s team was able to reproduce those results, but there was one key difference. “Our habitable zones are a little farther away from the star than what they get from their model because the planets get warmer faster,” he said. “This means the width of the habitable zone around M-dwarf stars is not as wide as previously thought.”

    Kopparapu said his team took into account Kepler’s third law of motion, which is a fundamental part of physics and astronomy. The law, simply put, says the time it takes a planet to orbit its star is roughly proportional to the size of its orbit. The older study assumed a constant orbital period of 60 days at the inner edge of the habitable zone, but the orbital and rotational period did not match what Kepler’s law predicts.

    More study is planned to refine the size of these habitable zones. Kopparapu has funding from NASA’s Habitable Worlds Grant. His proposal will update our understanding of how water vapor can absorb incoming radiation from the star. This can influence the warmth of a planet and further reduce the width of the habitable zone.

    Funding sources for the work include the NASA Astrobiology Institute’s Virtual Planetary Laboratory, the NASA Planetary Atmospheres Program, the Center for Exoplanets and Habitable Worlds, the National Science Foundation and Penn State Astrobiology Research Center.

    See the full article here .

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  • richardmitnick 7:54 am on June 3, 2016 Permalink | Reply
    Tags: , Daily Galaxy,   

    From Daily Galaxy: “‘Quantum Entanglement in Space’ – A New Global Satellite-Based Quantum Network” 

    Daily Galaxy
    The Daily Galaxy

    June 02, 2016
    No writer credit found

    1
    Image credit: With thanks to shockingscience.com

    “We are reaching the limits of how precisely we can test quantum theory on Earth,” says Daniel Oi at the University of Strathclyde. Researchers from the National University of Singapore (NUS) and the University of Strathclyde, UK, have become the first to test in orbit technology for satellite-based quantum network nodes. With a network that carries information in the quantum properties of single particles, you can create secure keys for secret messaging and potentially connect powerful quantum computers in the future. But scientists think you will need equipment in space to get global reach.

    They have put a compact device carrying components used in quantum communication and computing into orbit. And it works: the team report* first data in a paper published 31 May 2016 in the journal Physical Review Applied. The team’s device, dubbed SPEQS, creates and measures pairs of light particles, called photons. Results from space show that SPEQS is making pairs of photons with correlated properties — an indicator of performance.

    “This is the first time anyone has tested this kind of quantum technology in space,” said team-leader Alexander Ling, an Assistant Professor at the Centre for Quantum Technologies (CQT) at NUS.

    The team had to be inventive to redesign a delicate, table-top quantum setup to be small and robust enough to fly inside a nanosatellite only the size of a shoebox. The whole satellite weighs just 1.65-kilogramme.

    Making correlated photons is a precursor to creating entangled photons. Described by Einstein as “spooky action at a distance,” entanglement is a connection between quantum particles that lends security to communication and power to computing.

    “Alex and his team are taking entanglement, literally, to a new level. Their experiments will pave the road to secure quantum communication and distributed quantum computation on a global scale,” said Artur Ekert, Director of CQT, invented the idea of using entangled particles for cryptography. He said, I am happy to see that Singapore is one of the world leaders in this area.”

    Local quantum networks already exist. The problem Ling’s team aims to solve is a distance limit. Losses limit quantum signals sent through air at ground level or optical fibre to a few hundred kilometers — but we might ultimately use entangled photons beamed from satellites to connect points on opposite sides of the planet. Although photons from satellites still have to travel through the atmosphere, going top-to-bottom is roughly equivalent to going only 10 kilometres at ground level.

    The group’s first device is a technology pathfinder. It takes photons from a BluRay laser and splits them into two, then measures the pair’s properties, all on board the satellite. To do this it contains a laser diode, crystals, mirrors and photon detectors carefully aligned inside an aluminum block. This sits on top of a 10 centimetres by 10 centimetres printed circuit board packed with control electronics.

    Through a series of pre-launch tests — and one unfortunate incident — the team became more confident that their design could survive a rocket launch and space conditions. The team had a device in the October 2014 Orbital-3 rocket which exploded on the launch pad. The satellite containing that first device was later found on a beach intact and still in working order.

    Even with the success of the more recent mission, a global network is still a few milestones away. The team’s roadmap calls for a series of launches, with the next space-bound SPEQS slated to produce entangled photons. SPEQS stands for Small Photon-Entangling Quantum System.

    With later satellites, the researchers will try sending entangled photons to Earth and to other satellites. The team are working with standard “CubeSat” nanosatellites, which can get relatively cheap rides into space as rocket ballast. Ultimately, completing a global network would mean having a fleet of satellites in orbit and an array of ground stations.

    In the meantime, quantum satellites could also carry out fundamental experiments — for example, testing entanglement over distances bigger than Earth-bound scientists can manage.

    *Science paper:
    Generation and Analysis of Correlated Pairs of Photons aboard a Nanosatellite

    See the full article here .

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  • richardmitnick 10:11 am on May 23, 2016 Permalink | Reply
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    From Daily Galaxy: “”Attempt No Journey There” –Swarm of 10,000 Black Holes and Neutron Stars Orbit Milky Way’s Supermassive Black Hole” 

    Daily Galaxy
    The Daily Galaxy

    1
    No image caption, no image credit

    May 22, 2016

    “The giant black holes in the cores of galaxies, a million to 20 billion times heavier than the Sun, therefore, cannot have been born in the death of a star. They must have formed in some other way, perhaps by the agglomeration of many smaller black holes; perhaps by the collapse of massive clouds of gas.” ― Kip S. Thorne, The Science of Interstellar.

    “The Center of our Milky Way Galaxy is a place of extremes,” says Mark Morris, an expert on The Galactic Center at UCLA. “For every star in our nighttime sky, for example, there would be a million for someone looking up from a planet near the Galactic center.”

    Thinking about a far-future visit to our galaxy’s central zone, brings to mind Arthur C. Clark’s admonition about a visit to Jupiter’s ocean moon, Europa –“All These Worlds are Yours –Except Europa Attempt No Landing There.” In addition to the extreme star density, a swarm of 10,000 or more black holes may be orbiting the Milky Way’s supermassive black hole, according to observations from NASA’s Chandra X-ray Observatory in 2015.

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way”

    This would represent the highest concentration of black holes anywhere in the Galaxy. These relatively small, stellar-mass black holes, along with neutron stars, appear to have migrated into the Galactic Center over the course of several billion years. Could this migration be the prelude to feeding our supermassive black hole suggested by Caltech’s Kip Thorne?

    The discovery was made as part of Chandra’s ongoing program of monitoring the region around Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, reported by by Michael Muno of the University of California, Los Angeles (UCLA) at a 2015 meeting of the American Astronomical Society.

    Among the thousands of X-ray sources detected within 70 light years of Sgr A*, Muno and his colleagues searched for those most likely to be active black holes and neutron stars by selecting only the brightest sources that also exhibited large variations in their X-ray output. These characteristics identify black holes and neutron stars that are in binary star systems and are pulling matter from nearby companion stars. Of the seven sources that met these criteria, four are within three light years of Sgr A*.

    “Although the region around Sgr A* is crowded with stars, we expected that there was only a 20 percent chance that we would find even one X-ray binary within a three-light-year radius,” said Muno. “The observed high concentration of these sources implies that a huge number of black holes and neutron stars have gathered in the center of the Galaxy.”

    Mark Morris, also of UCLA and a coauthor on the present work, had predicted a decade ago that a process called dynamical friction would cause stellar black holes to sink toward the center of the Galaxy. Black holes are formed as remnants of the explosions of massive stars and have masses of about 10 suns. As black holes orbit the center of the Galaxy at a distance of several light years, they pull on surrounding stars, which pull back on the black holes.

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    Unidentified. No image credit.

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    The images above are part of a Chandra program that monitors a region around the Milky Way’s supermassive black hole, Sagittarius A* (Sgr A*). Four bright, variable X-ray sources (circles) were discovered within 3 light years of Sgr A* (the bright source just above Source C). The lower panel illustrates the strong variability of one of these sources. This variability, which is present in all the sources, is indicative of an X-ray binary system where a black hole or neutron star is pulling matter from a nearby companion star.

    “Stars are packed quite close together in the center zone,” says Morris. “Then, there’s that supermassive black hole that is sitting in there, relatively quiet for now, but occasionally producing a dramatic outpouring of energy. The UCLA Galactic center group been use the Keck Telescopes in Hawaii to follow its activity for the last 17 years, watching not only the fluctuating emission from the black hole, but also watching the stars around it as they rapidly orbit the black hole.”

    Morris had predicted a decade ago that a process called dynamical friction would cause stellar black holes to sink toward the center of the Galaxy. Black holes are formed as remnants of the explosions of massive stars and have masses of about 10 suns. As black holes orbit the center of the Galaxy at a distance of several light years, they pull on surrounding stars, which pull back on the black holes. The net effect is that black holes spiral inward, and the low-mass stars move out. From the estimated number of stars and black holes in the Galactic Center region, dynamical friction is expected to produce a dense swarm of 20,000 black holes within three light years of Sgr A*. A similar effect is at work for neutron stars, but to a lesser extent because they have a lower mass.

    Once black holes are concentrated near Sgr A*, they will have numerous close encounters with normal stars there, some of which are in binary star systems. The intense gravity of a black hole can induce an ordinary star to “change partners” and pair up with the black hole while ejecting its companion. This process and a similar one for neutron stars are expected to produce several hundreds of black hole and neutron star binary systems.

    The black holes and neutron stars in the cluster are expected to gradually be swallowed by the supermassive black hole, Sgr A*, at a rate of about one every million years. At this rate, about 10,000 black holes and neutron stars would have been captured in a few billion years, adding about 3 percent to the mass of the central supermassive black hole, which is currently estimated to contain the mass of 3.7 million suns.

    In the meantime, the acceleration of low-mass stars by black holes will eject low-mass stars from the central region. This expulsion will reduce the likelihood that normal stars will be captured by the central supermassive black hole. This may explain why the central regions of some galaxies, including the Milky Way, are fairly quiet even though they contain a supermassive black hole.

    See the full article here .

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  • richardmitnick 8:05 am on May 6, 2016 Permalink | Reply
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    From Daily Galaxy: “China’s Journey to the Far Side of the Moon –“Will It Lead to the 1st Radio Telescope Beyond Earth?” 

    Daily Galaxy
    The Daily Galaxy

    May 05, 2016
    No writer credit found

    1
    Image credits: svs.gsfc.nasa.gov

    China’s Chang’e 4 mission to the far side of the moon, planned for sometime before 2020 could eventually lead to the placement of a radio telescope for use by astronomers, something that would help “fill a void” in man’s knowledge of the universe, according to Zou Yongliao with the Chinese Academy of Sciences’ moon exploration department during a September 2015 interview on state broadcaster CCTV.

    Chang'e 4 China
    Chang’e 4 China

    Radio transmissions from Earth are unable to reach the moon’s far side, making it an excellent location for sensitive instruments.China’s increasingly ambitious space program plans to attempt the first-ever landing of a lunar probe on the moon’s far side, a leading engineer said. Zou said the mission’s objective would be to study geological conditions on the moon’s far side.

    Topography of the near side (left) and far side (right) of moon shown below. On the map white and red colors represent high terrains and blue and purple are low terrains.

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    Meanwhile, back on Earth, China has constructed reflection panels for the world’s biggest radio telescope, the Five hundred meter Aperture Spherical Telescope (FAST).

    FAST Chinese Radio telescope under construction
    FAST Chinese Radio telescope under construction, Guizhou Province, China

    This radio telescope with an aperture of 500 meters is under construction in a natural basin in Guizhou Province. The telescope-under-construction has thousands of reflection panels; eventually the positions of these panels can be adjusted simultaneously to better receive radio waves from moving celestial bodies.

    The radio telescope will be twice as sensitive as the Arecibo Observatory operated by the United States.

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA

    (Interestingly FAST was previously announced to become 3-times as sensitive, this is either a simple typing error or an adjustment in expectation.) The new telescope is also capable of collecting data even from the outer rim of the solar system. The telescope should be finished and installed by September 2016. As said, once successfully constructed the telescope will become the world’s largest and most sensitive radio telescope.

    It seems that the two sides of the moon have evolved differently since their formation, with the far side forming at cooler temperatures and remaining stiffer while the Earth side has been modified at higher temperatures and for longer. This information is extremely important for theories on the formation of the moon, of which the current favorite is the “Giant Impact” hypothesis.

    The Giant Impact idea is that four and a half billion years ago a planet the size of Mars [Theia] rammed Earth, kicking enough debris into orbit to accrete into an entirely new body. New research from geophysical scientist Junjun Zhang and colleagues at Origins Lab at the University of Chicago, suggests that the giant impact hypothesis of the creation of the Moon might be wrong. The team found that in comparing titanium isotopes from both the moon and the Earth, that the match is too close to support the theory that the moon could have been made partly of material from another planet.

    On the other hand, the researchers found that the Moon did show a similar composition of the silicon isotopic composition as the Earth. However, it, too, is much smaller than the Earth—about one-fiftieth as large as the Earth and about one percent of the Earth’s mass—making it even less likely to have been able to generate enough pressure to form an Earth-like iron core. This research was the first of its kind using isotopes in this manner and offers intriguing insights into the creation of Mars, the Earth, and the Moon. It may also help explain how life evolved on the Earth and whether or not it might have existed at some time on Mars..

    Because the moon is tidally locked (meaning the same side always faces Earth), it was not until 1959 that the farside was first imaged by the Soviet Luna 3 spacecraft (hence the Russian names for prominent farside features, such as Mare Moscoviense). And what a surprise -­ unlike the widespread maria on the nearside, basaltic volcanism was restricted to a relatively few, smaller regions on the farside, and the battered highlands crust dominated. A different world from what we saw from Earth.

    China’s next lunar mission is scheduled for 2017, when it will attempt to land an unmanned spaceship on the moon before returning to Earth with samples. If successful, that would make China only the third country after the United States and Russia to have carried out such a maneuver.

    See the full article here .

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  • richardmitnick 3:21 pm on April 10, 2016 Permalink | Reply
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    From The Daily Galaxy: “CERN LHC Reveals: “The Universe a Billionth of a Second After the Big Bang” 

    Daily Galaxy
    The Daily Galaxy

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    April 09, 2016
    No writer credit found

    “It is remarkable that we are able to carry out such detailed measurements on a drop of ‘early universe’, that only has a radius of about one millionth of a billionth of a meter. The results are fully consistent with the physical laws of hydrodynamics, i.e. the theory of flowing liquids and it shows that the quark-gluon plasma behaves like a fluid.

    It is however a very special liquid, as it does not consist of molecules like water, but of the fundamental particles quarks and gluons,” explained Jens Jørgen Gaardhøje, professor and head of the ALICE group at the Niels Bohr Institute at the University of Copenhagen.

    A few billionths of a second after the Big Bang, the universe was made up of a kind of extremely hot and dense primordial soup of the most fundamental particles, especially quarks and gluons. This state is called quark-gluon plasma. By colliding lead nuclei at a record-high energy of 5.02 TeV in the world’s most powerful particle accelerator, the 27 km long Large Hadron Collider, LHC at CERN in Geneva, it has been possible to recreate this state in the ALICE experiment’s detector and measure its properties.

    Quark gluon plasma. Duke University
    Quark-gluon plasma. Duke University

    CERN researchers recreated the universe’s primordial soup in miniature format by colliding lead atoms with extremely high energy in the 27 km long particle accelerator, the LHC in Geneva. The primordial soup is a so-called quark-gluon plasma and researchers from the Niels Bohr Institute, among others, have measured its liquid properties with great accuracy at the LHC’s top energy. The results were submitted to Physical Review Letters, which is the top scientific journal for nuclear and particle physics.

    “The analyses of the collisions make it possible, for the first time, to measure the precise characteristics of a quark-gluon plasma at the highest energy ever and to determine how it flows,” explains You Zhou, who is a postdoc in the ALICE research group at the Niels Bohr Institute.

    CERN ALICE Icon HUGE
    ALICE Run Control Center
    CERN ALICE New
    CERN ALICE New II
    CERN ALICE and the Control Room

    You Zhou, together with a small, fast-working team of international collaboration partners, led the analysis of the new data and measured how the quark-gluon plasma flows and fluctuates after it is formed by the collisions between lead ions.

    The focus has been on the quark-gluon plasma’s collective properties, which show that this state of matter behaves more like a liquid than a gas, even at the very highest energy densities. The new measurements, which uses new methods to study the correlation between many particles, make it possible to determine the viscosity of this exotic fluid with great precision.

    You Zhou explains that the experimental method is very advanced and is based on the fact that when two spherical atomic nuclei are shot at each other and hit each other a bit off center, a quark-gluon plasma is formed with a slightly elongated shape somewhat like an American football. This means that the pressure difference between the centre of this extremely hot ‘droplet’ and the surface varies along the different axes. The pressure differential drives the expansion and flow and consequently one can measure a characteristic variation in the number of particles produced in the collisions as a function of the angle.

    Jens Jørgen Gaardhøje adds that they are now in the process of mapping this state with ever increasing precision — and even further back in time.

    See the full article here .

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  • richardmitnick 9:49 am on January 15, 2016 Permalink | Reply
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    From Daily Galaxy: “”Nixing 100 Billion Galaxies” –Bayesian Reasoning Dismisses Existence of Alien Life” 

    Daily Galaxy
    The Daily Galaxy

    January 14, 2016
    No writer credit found

    Temp 1
    Image credits: NASA/ESA/IAC/HFF Team, STScI

    Carl Sagan said that “extraordinary claims, require extraordinary evidence.” In a stunning display of mathematical logic, David Spiegel of Princeton University and Edwin Turner from the University of Tokyo published a paper in 2012 that turns the Drake equation upside down using Bayesian reasoning to show that just because we evolved on Earth, doesn’t mean that the same occurrence would necessarily happen elsewhere; “using evidence of our own existence doesn’t show anything” they argue, “other than that we are here.”
    The recent Kepler Space-Telescope discoveries of planets similar to Earth in size and proximity to the planets’ respective suns have sparked scientific and public excitement about the possibility of also finding Earth-like life on those worlds.

    NASA Kepler Telescope
    NASA/Kepler

    But the Princeton University researchers have found that the expectation that life — from bacteria to sentient beings — has or will develop on other planets as on Earth might be based more on optimism than scientific evidence.

    Astrophysical sciences professor Turner and lead author Spiegel analyzed what is known about the likelihood of life on other planets in an effort to separate the facts from the mere expectation that life exists outside of Earth. The researchers used a Bayesian analysis — which weighs how much of a scientific conclusion stems from actual data and how much comes from the prior assumptions of the scientist — to determine the probability of extraterrestrial life once the influence of these presumptions is minimized.

    Turner and Spiegel, who is now at the Institute for Advanced Study, argued in the Proceedings of the National Academy of Sciences [no link to paper] that the idea that life has or could arise in an Earth-like environment has only a small amount of supporting evidence, most of it extrapolated from what is known about abiogenesis, or the emergence of life, on early Earth. Instead, their analysis showed that the expectations of life cropping up on exoplanets — those found outside Earth’s solar system — are largely based on the assumption that it would or will happen under the same conditions that allowed life to flourish on this planet.

    In fact, the researchers conclude, the current knowledge about life on other planets suggests that it’s very possible that Earth is a cosmic aberration where life took shape unusually fast. If so, then the chances of the average terrestrial planet hosting life would be low.

    “Fossil evidence suggests that life began very early in Earth’s history and that has led people to determine that life might be quite common in the universe because it happened so quickly here, but the knowledge about life on Earth simply doesn’t reveal much about the actual probability of life on other planets,” Turner said.

    “Information about that probability comes largely from the assumptions scientists have going in, and some of the most optimistic conclusions have been based almost entirely on those assumptions,” he said.

    Turner and Spiegel used Bayes’ theorem to assign a sliding mathematical weight to the prior assumption that life exists on other planets. The “value” of that assumption was used to determine the probability of abiogenesis, in this case defined as the average number of times that life arises every billion years on an Earth-like planet. Turner and Spiegel found that as the influence of the assumption increased, the perceived likelihood of life existing also rose, even as the basic scientific data remained the same.

    “If scientists start out assuming that the chances of life existing on another planet as it does on Earth are large, then their results will be presented in a way that supports that likelihood,” Turner said. “Our work is not a judgment, but an analysis of existing data that suggests the debate about the existence of life on other planets is framed largely by the prior assumptions of the participants.”

    Joshua Winn, an associate professor of physics at the Massachusetts Institute of Technology, said that Turner and Spiegel cast convincing doubt on a prominent basis for expecting extraterrestrial life. Winn, who focuses his research on the properties of exoplanets, is familiar with the research but had no role in it.

    “There is a commonly heard argument that life must be common or else it would not have arisen so quickly after the surface of the Earth cooled,” Winn said. “This argument seems persuasive on its face, but Spiegel and Turner have shown it doesn’t stand up to a rigorous statistical examination — with a sample of only one life-bearing planet, one cannot even get a ballpark estimate of the abundance of life in the universe.

    “I also have thought that the relatively early emergence of life on Earth gave reasons to be optimistic about the search for life elsewhere,” Winn said. “Now I’m not so sure, though I think scientists should still search for life on other planets to the extent we can.”

    Deep-space satellites and telescope projects have recently identified various planets that resemble Earth in their size and composition, and are within their star’s habitable zone, the optimal distance for having liquid water.

    Of particular excitement have been the discoveries of NASA’s Kepler Space Telescope. In December 2011, NASA announced the first observation of Kepler-22b, a planet 600 light years from Earth and the first found within the habitable zone of a Sun-like star.

    Temp 3
    Kepler-22b — Comfortably Circling within the Habitable Zone.This diagram compares our solar system to Kepler-22, a star system containing the first “habitable zone” planet discovered by NASA’s Kepler mission. The habitable zone is the spot around a star where temperatures are right for water to exist in its liquid form. Liquid water is essential for life on Earth.

    Kepler-22’s star is a bit smaller than our sun, so its habitable zone is slightly closer in. The diagram shows an artist’s rendering of the planet comfortably orbiting within the habitable zone, similar to where Earth circles the sun. Kepler-22b has a yearly orbit of 289 days. The planet is the smallest known to orbit in the middle of the habitable zone of a sun-like star. It’s about 2.4 times the size of Earth.
    Image credit: NASA/Ames/JPL-Caltech
    Date 5 December 2011

    Weeks later, NASA reported Keplers-20e and -20f, the first Earth-sized planets found orbiting a Sun-like star. NASA has since announced the discovery of over 2000 Kepler planets, with some 500 possible Earth-like candidates.

    While these observations tend to stoke the expectation of finding Earth-like life, they do not actually provide evidence that it does or does not exist, Spiegel explained. Instead, these planets have our knowledge of life on Earth projected onto them, he said.

    Yet, when what is known about life on Earth is taken away, there is no accurate sense of how probable abiogenesis is on any given planet, Spiegel said. It was this “prior ignorance,” or lack of expectations, that he and Turner wanted to account for in their analysis, he said.

    “When we use a mathematical prior that truly represents prior ignorance, the data of early life on Earth becomes ambiguous,” Spiegel said.

    “Our analysis suggests that abiogenesis could be a rather rapid and probable process for other worlds, but it also cannot rule out at high confidence that abiogenesis is a rare, improbable event,” Spiegel said. “We really have no idea, even to within orders of magnitude, how probable abiogenesis is, and we show that no evidence exists to substantially change that.”

    Spiegel and Turner also propose that once this planet’s history is considered, the emergence of life on Earth might be so distinct that it is a poor barometer of how it occurred elsewhere, regardless of the likelihood that such life exists.

    In a philosophical turn, they suggest that because humans are the ones wondering about the emergence of life, it is possible that we must be on a planet where life began early in order to reach a point so soon after the planet’s formation 4.5 billion years ago where we could wonder about it.

    Thus, Spiegel and Turner explored how the probability of exoplanetary abiogenesis would change if it turns out that evolution requires, as it did on Earth, roughly 3.5 billion years for life to develop from its most basic form to complex organisms capable of pondering existence. If that were the case, then the 4.5 billion-year-old Earth clearly had a head start. A planet of similar age where life did not begin until several billion years after the planet formed would have only basic life forms at this point.

    “Dinosaurs and horseshoe crabs, which were around 200 million years ago, presumably did not consider the probability of abiogenesis. So, we would have to find ourselves on a planet with early abiogenesis to reach this point, irrespective of how probable this process actually is,” Spiegel said. “This evolutionary timescale limits our ability to make strong inferences about how probable abiogenesis is.”

    Turner added, “It could easily be that life came about on Earth one way, but came about on other planets in other ways, if it came about at all. The best way to find out, of course, is to look. But I don’t think we’ll know by debating the process of how life came about on Earth.”

    Again, said Winn of MIT, Spiegel and Turner offer a unique consideration for scientists exploring the possibility of life outside of Earth.

    “I had never thought about the subtlety that we as a species could never have ‘found’ ourselves on a planet with a late emergence of life if evolution takes a long time to produce sentience, as it probably does,” Winn said.

    “With that in mind,” he said, “it seems reasonable to say that scientists cannot draw any strong conclusion about life on other planets based on the early emergence of life on Earth.”

    What Bayesian reasoning overlooks, of course, is the inconvenient fact that there are some one trillion galaxies in the known universe and some 50 billion planets estimated to exist in the Milky Way alone and some 500,000,000 predicted to exist in a habitable zone. Spiegel and Turner point out that basing our expectations of life existing on other planets, for no better reason that it exists here, is really only proof that were are more than capable of deceiving ourselves into thinking that things are much more likely than they really are.

    NASA’s Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies shown below that were gravitationally ripped apart several billion years ago. The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed “Pandora’s Cluster,” also known as Abell 2744. The Hubble team estimates that the combined light of about 200 billion outcast stars contributes approximately 10 percent of the cluster’s brightness.

    Temp 2
    No image credit found

    NASA Hubble Telescope
    NASA/ESA Hubble

    They argue that other unknown factors exist that could have contributed to us being here that we don’t yet understand. So, they conclude that, deriving numbers from an equation such as that put forth by Drake, only serves to underscore our belief in the existence of other alien life forms, rather than the actual chances of it being so.

    We think evidence will be discovered in the next 20 years: The Kepler mission has discovered 1,235 exoplanets that revolve around a sun, in an area that represents around 1/400th of the Milky Way. By extrapolating these numbers, the Kepler team has estimated that there are at least 50 billion exoplanets in our galaxy — 500 million of which sit inside the habitable “Goldilocks” zones of their suns, the area that it is neither too hot nor too cold to support life.

    Astronomers estimate that there are 100 billion galaxies in the universe. If you want to extrapolate those numbers, that means there are around 50,000,000,000,000,000,000 (50 quintillion) potentially habitable planets in the universe.

    As Arthur C. Clarke, physicist and author of 2001: A Space Odyssey wrote, “The idea that we are the only intelligent creatures in a cosmos of a hundred billion galaxies is so preposterous that there are very few astronomers today who would take it seriously. It is safest to assume therefore, that they are out there and to consider the manner in which this may impinge upon human society.”To an objectivist, empirical view, the rules of Bayesian statistics can be justified by requirements of rationality and consistency and interpreted as an extension of logic. Using a subjectivist view, however, the state of knowledge measures a “personal belief”.

    More information: “Life might be rare despite its early emergence on Earth: a Bayesian analysis of the probability of abiogenesis” http://arxiv.org/abs/1107.3835 and physorg.com

    The Daily Galaxy via Princeton University

    Image credit: Image credit: NASA/ESA/IAC/HFF Team, STScI

    See the full article here .

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  • richardmitnick 4:12 pm on January 2, 2016 Permalink | Reply
    Tags: , , Daily Galaxy, ,   

    From PI Via Daily Galaxy: “The Big Bang was a Mirage from a Collapsing Higher-Dimensional Star” February 2015 but Very Interesting 

    Daily Galaxy
    The Daily Galaxy

    Perimeter Institute
    Perimeter Institute
    Perimeter Institute bloc

    February 14, 2015 [Just brought forward – again]
    No writer credit

    Temp 1

    Big Bang was a mirage from collapsing higher-dimensional star, theorists propose. While the recent [ESA]Planck results “prove that inflation is correct”, they leave open the question of how inflation happened.

    ESA Planck
    ESA/Planck

    A new The study could help to show how inflation was triggered by the motion of the Universe through a higher-dimensional reality.
    The event horizon of a black hole — the point of no return for anything that falls in — is a spherical surface. In a higher-dimensional universe, a black hole could have a three-dimensional event horizon, which could spawn a whole new universe as it forms.

    It could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole — a scenario that would help to explain why the cosmos seems to be so uniform in all directions.

    Cosmic Background Radiation Planck
    CMB per Planck

    The standard Big Bang model tells us that the Universe exploded out of an infinitely dense point, or singularity. But nobody knows what would have triggered this outburst: the known laws of physics cannot tell us what happened at that moment.

    “For all physicists know, dragons could have come flying out of the singularity,” says Niayesh Afshordi, an astrophysicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada.

    It is also difficult to explain how a violent Big Bang would have left behind a Universe that has an almost completely uniform temperature, because there does not seem to have been enough time since the birth of the cosmos for it to have reached temperature equilibrium.

    To most cosmologists, the most plausible explanation for that uniformity is that, soon after the beginning of time, some unknown form of energy made the young Universe inflate at a rate that was faster than the speed of light. That way, a small patch with roughly uniform temperature would have stretched into the vast cosmos we see today. But Afshordi notes that “the Big Bang was so chaotic, it’s not clear there would have been even a small homogenous patch for inflation to start working on”.

    In a paper posted last week on the arXiv preprint server1, Afshordi and his colleagues turn their attention to a proposal made in 2000 by a team including Gia Dvali, a physicist now at the Ludwig Maximilians University in Munich, Germany. In that model, our three-dimensional (3D) Universe is a membrane, or brane, that floats through a ‘bulk universe’ that has four spatial dimensions.

    Ashfordi’s team realized that if the bulk universe contained its own four-dimensional (4D) stars, some of them could collapse, forming 4D black holes in the same way that massive stars in our Universe do: they explode as supernovae, violently ejecting their outer layers, while their inner layers collapse into a black hole.

    In our Universe, a black hole is bounded by a spherical surface called an event horizon. Whereas in ordinary three-dimensional space it takes a two-dimensional object (a surface) to create a boundary inside a black hole, in the bulk universe the event horizon of a 4D black hole would be a 3D object — a shape called a hypersphere. When Afshordi’s team modelled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.

    The authors postulate that the 3D Universe we live in might be just such a brane — and that we detect the brane’s growth as cosmic expansion. “Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage,” says Afshordi.

    The model also naturally explains our Universe’s uniformity. Because the 4D bulk universe could have existed for an infinitely long time in the past, there would have been ample opportunity for different parts of the 4D bulk to reach an equilibrium, which our 3D Universe would have inherited.

    The picture has some problems, however. Earlier this year, the European Space Agency’s Planck space observatory released data that mapped the slight temperature fluctuations in the cosmic microwave background — the relic radiation that carries imprints of the Universe’s early moments. The observed patterns matched predictions made by the standard Big Bang model and inflation, but the black-hole model deviates from Planck’s observations by about 4%. Hoping to resolve the discrepancy, Afshordi says that his is now refining its model.

    Despite the mismatch, Dvali praises the ingenious way in which the team threw out the Big Bang model. “The singularity is the most fundamental problem in cosmology and they have rewritten history so that we never encountered it,” he says. Whereas the Planck results “prove that inflation is correct”, they leave open the question of how inflation happened, Dvali adds. The study could help to show how inflation is triggered by the motion of the Universe through a higher-dimensional reality, he says.

    Nature doi:10.1038/nature.2013.13743

    See the full article here .

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  • richardmitnick 8:20 am on December 12, 2015 Permalink | Reply
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    From Daily Galaxy: “”Gravity Alters the Quantum Nature of Particles on Earth” –What Does It Imply at Cosmological Scales?” 

    Daily Galaxy
    The Daily Galaxy

    December 11, 2015
    University of Vienna

    1

    “It is quite surprising that gravity can play any role in quantum mechanics“, says Igor Pikovski, a theoretical physicist working at the Harvard-Smithsonian Center for Astrophysics:”Gravity is usually studied on astronomical scales, but it seems that it also alters the quantum nature of the smallest particles on Earth”. “It remains to be seen what the results imply on cosmological scales, where gravity can be much stronger”, adds Caslav Brukner University Professor at the University of Vienna and Director of the Institute for Quantum Optics and Quantum Information.

    In 1915 Albert Einstein formulated the theory of general relativity which fundamentally changed our understanding of gravity. He explained gravity as the manifestation of the curvature of space and time. Einstein’s theory predicts that the flow of time is altered by mass. This effect, known as “gravitational time dilation“, causes time to be slowed down near a massive object. It affects everything and everybody; in fact, people working on the ground floor will age slower than their colleagues a floor above, by about 10 nanoseconds in one year. This tiny effect has actually been confirmed in many experiments with very precise clocks.

    This past June, a team of researchers from the University of Vienna, Harvard University and the University of Queensland discovered that the slowing down of time can explain another perplexing phenomenon: the transition from quantum behavior to our classical, everyday world.

    The image below is an illustration of a molecule in the presence of gravitational time dilation. The molecule is in a quantum superposition of being several places at the same time.

    2

    Quantum theory, the other major discovery in physics in the early 20th century, predicts that the fundamental building blocks of nature show fascinating and mind-boggling behavior. Extrapolated to the scales of our everyday life quantum theory leads to situations such as the famous example of Schroedinger’s cat: the cat is neither dead nor alive, but in a so-called quantum superposition of both.

    4

    Yet such a behavior has only been confirmed experimentally with small particles and has never been observed with real-world cats. Therefore, scientists conclude that something must cause the suppression of quantum phenomena on larger, everyday scales. Typically this happens because of interaction with other surrounding particles.

    The research team, headed by ?aslav Brukner from the University of Vienna and the Institute of Quantum Optics and Quantum Information, found that time dilation also plays a major role in the demise of quantum effects. They calculated that once the small building blocks form larger, composite objects – such as molecules and eventually larger structures like microbes or dust particles -, the time dilation on Earth can cause a suppression of their quantum behavior.

    The tiny building blocks jitter ever so slightly, even as they form larger objects. And this jitter is affected by time dilation: it is slowed down on the ground and speeds up at higher altitudes. The researchers have shown that this effect destroys the quantum superposition and, thus, forces larger objects to behave as we expect in everyday life.

    The results of Pikovski and his co-workers reveal how larger particles lose their quantum behavior due to their own composition, if one takes time dilation into account. This prediction should be observable in experiments in the near future, which could shed some light on the fascinating interplay between the two great theories of the 20th century, quantum theory and general relativity.

    Publication in Nature Physics: “Universal decoherence due to gravitational time dilation”. I. Pikovski, M. Zych, F. Costa, C. Brukner. Nature Physics (2015) doi:10.1038/nphys3366

    See the full article here .

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  • richardmitnick 12:12 pm on October 11, 2015 Permalink | Reply
    Tags: , , Daily Galaxy,   

    From Daily Galaxy: “The Dark Matter Enigma: “Is It the ‘Operating System’ of Our Universe?” (Weekend Feature)” 

    Daily Galaxy
    The Daily Galaxy

    10-11-15
    No Writer Credit

    1
    No image credit

    Is dark matter the “operating system” of the Universe? Tom Broadhurst, an Ikerbasque researcher at the UPV/EHU’s Department of Theoretical Physics, thinks it is. He has participated alongside scientists of the National Taiwan University in a piece of research that explores cold dark matter in depth and proposes new answers about the formation of galaxies and the structure of the Universe. These predictions are being contrasted with data provided by the Hubble space telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    In cosmology, cold dark matter is a form of matter the particles of which move slowly in comparison with light, and interact weakly with electromagnetic radiation. It is estimated that only a minute fraction of the matter in the Universe is baryonic matter, which forms stars, planets and living organisms. The rest, comprising over 80%, is dark matter and energy.

    The theory of cold dark matter helps to explain how the universe evolved from its initial state to the current distribution of galaxies and clusters, the structure of the Universe on a large scale. In any case, the theory was unable to satisfactorily explain certain observations, but the new research by Broadhurst and his colleagues sheds new light in this respect.

    As the Ikerbasque researcher explained, “guided by the initial simulations of the formation of galaxies in this context, we have reinterpreted cold dark matter as a Bose-Einstein condensate“. So, “the ultra-light bosons forming the condensate share the same quantum wave function, so disturbance patterns are formed on astronomic scales in the form of large-scale waves”.

    This theory can be used to suggest that all the galaxies in this context should have at their center large stationary waves of dark matter called solitons, which would explain the puzzling cores observed in common dwarf galaxies.

    2
    The Large Magellanic Cloud, a satellite [dwarf] galaxy of the Milky Way. Picture taken by Hubble.

    The image at the top of the page shows a comparison of the radial density profiles of the galaxies which the researchers have created by displaying the soliton in the centre of each galaxy with a halo surrounding it. The solitons are broader but have less mass in the smaller galaxies.

    The image left, below, shows that a comparison of the distribution of matter is very similar on a large scale between wave dark matter, the focus of this research, and the usual dark matter particle.

    Image right shows that in galaxies the structure is very different in the interpretation of the wave, which has been carried out in this research; the research predicts the soliton of dark matter in the centre surrounded by an extensive halo of dark matter in the form of large “spots”, which are the slowly fluctuating density waves. This leads to many predictions and solves the problem of puzzling cores in smaller galaxies.

    2

    The research also makes it possible to predict that galaxies are formed relatively late in this context in comparison with the interpretation of standard particles of cold dark matter. The team is comparing these new predictions with observations by the Hubble space telescope.

    The results are very promising as they open up the possibility that dark matter could be regarded as a very cold quantum fluid that governs the formation of the structure across the whole Universe.

    This was not Thomas Broadhurst’s first publication in the prestigious journal Nature. In 2012, he participated in a piece of research on a galaxy of the epoch of the reionization, a stage in the early universe not explored previously and which could be the oldest galaxy discovered. This research opened up fresh possibilities to conduct research into the first galaxies to emerge after the Big Bang.

    Broadhurst has a PhD in Physics from the University of Durham (United Kingdom). In 2010, he was recruited by Ikerbasque and carries out his work in the UPV/EHU’s department of Theoretical Physics. His line of research focuses on observational cosmology, dark matter and the formation of galaxies.

    See the full article here .

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    • gonmrm 12:33 pm on October 11, 2015 Permalink | Reply

      Really great images! Thanks for sharing such interesting space related post! Visit my blog, maybe you’ll enjoy it as much as I enjoyed your post! https://thebeautyinspace.wordpress.com
      Gonçalo

      Like

    • richardmitnick 12:54 pm on October 11, 2015 Permalink | Reply

      You know, a lot of people tell me that the images are good, or great, but I am just using what I find in the articles, or sometimes, I need to get my own images. I have a large folder of images, telescopes and the like, all from Google images or the web sites from which the images originate.

      So, I cannot claim any credit for the images. They are available to anyone.

      Like

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