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  • richardmitnick 3:51 pm on November 30, 2018 Permalink | Reply
    Tags: Discover Magazine, Magnitude 7 Earthquakes Hits Near Anchorage   

    From Discover Magazine: “Magnitude 7 Earthquakes Hits Near Anchorage” 

    DiscoverMag

    From Discover Magazine

    November 30, 2018
    Erik Klemetti

    1
    Shake map for the M7 earthquake that struck near Anchorage on November 30, 2018. USGS.

    Earlier today a M7 earthquake struck only 13 kilometers from Anchorage, Alaska. The earthquake was relatively deep, located ~40 kilometers beneath the surface. However, the city of Anchorage has experienced damage from the shaking. Anchorage airport has seen disruptions as the control tower was evacuated (and is apparently running out of a truck right now).

    More importantly, a tsunami warning was declared for the coast of Alaska, so people are trying to evacuate the area. However, a Pacific-wide tsunami is not expected according to the Pacific Tsunami Warning Center.

    See the full article here .

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  • richardmitnick 8:52 pm on November 12, 2018 Permalink | Reply
    Tags: , , , , Dark matter hurricane, Discover Magazine, S1 stream,   

    From Discover Magazine: “A ‘Dark Matter Hurricane’ is Storming Past Earth. It Could Help Scientists Detect the Strange Substance” 

    DiscoverMag

    From Discover Magazine

    November 12, 2018
    Chelsea Gohd

    1
    The Milky Way is shown on a collision course with a smaller galaxy in this simulation. (Credit: Koppelman, Villalobos; Helmi, Kapteyn Astronomical Institute, University of Groningen, The Netherlands)

    There’s a “dark matter hurricane” blowing through our corner of the Milky Way galaxy. Right this second, it’s passing over Earth. And this fast-moving stream could reveal major details about dark matter, a new study finds.

    The dark matter is traveling in what is known as the S1 stream. Scientists think that streams like this one are the cosmic debris leftover when small galaxies stray too close to the Milky Way. Our gravitational forces tear the smaller galaxy apart, leaving behind a traveling, elliptical stream of stars, dark matter and other debris.

    Dark Matter Hurricane

    Dark matter is an elusive material that scientists think, if the Standard Model is correct, exists in large quantities throughout space. Scientists still don’t know what dark matter actually is — there are a number of leading theories, but no one knows for sure.

    Women in STEM – Vera Rubin
    Fritz Zwicky discovered Dark Matter when observing the movement of the Coma Cluster

    Coma cluster via NASA/ESA Hubble

    But most of the real work was done by Vera Rubin

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


    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

    But the S1 stream is predicted to be blowing dark matter past us at about 310 miles per second (500 km/s) right this moment, and that could provide an opportunity for detection.

    Galactic Streams

    Dozens of such streams have been found in the Milky Way. And like the galaxies they’re stripped from, these streams are typically made of stars and dark matter all traveling along together at the same velocity. “(There are) tons of these streams all over the galaxy, some of them are really huge and you can see them in the sky,” said Ciaran O’Hare of the University of Zaragoza in Spain.

    The European Space Agency’s billion-star survey using the Gaia spacecraft is reaching far out into our galaxy to discover and observe stars.

    ESA/GAIA satellite

    And Gaia picked out the S1 stream because its some 30,000 stars have a different chemical composition than those native to our galaxy. And they’re traveling along a similar, elliptical path.

    And, while there are over 30 such streams known in our galaxy, S1 still surprised astronomers because our solar system is actually inside this stream. And our paths will intersect for millions of more years. Now, this will not affect our lives or planet in any physical way – there is still only one star (the sun) in our solar system.

    But O’Hare and his colleagues calculated the affect of the S1 stream in our part of the galaxy and predicted possible signatures of the dark matter, which could help inform and support efforts to locate and study the elusive substance.

    “What we want to do is add the stream as part of our kind of main prediction for the types of signal that should show up in a dark matter experiment,” O’Hare said. According to a statement, current detectors searching for weakly interacting massive particles (WIMPs) (one popular idea of what dark matter might be) probably won’t see anything from S1, but future tech might.

    Their study was published in the journal Physical Review D.

    See the full article here .

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  • richardmitnick 9:17 am on November 1, 2018 Permalink | Reply
    Tags: , Discover Magazine, , , ,   

    From Discover Magazine: “Meet the Biochemist Engineering Proteins From Scratch” 

    DiscoverMag

    From Discover Magazine

    October 30, 2018
    Jonathon Keats

    1
    David Baker. Brian Dalbalcon/UW Medicine

    U Washington Dr. David Baker

    In a sleek biochemistry laboratory at the University of Washington, postdoctoral fellow Yang Hsia is watching yellowish goo — the liquefied remains of E. coli — ooze through what looks like a gob of white marshmallow. “This isn’t super exciting,” he says.

    While growing proteins in bacteria and then purifying them, using blobby white resin as a filter, doesn’t make for riveting viewing, the end product is extraordinary. Accumulating in Hsia’s resin is a totally artificial protein, unlike anything seen in nature, that might just be the ideal chassis for the first universal flu vaccine.

    David Baker, Hsia’s adviser, calls this designer protein a “Death Star.” Imaged on his computer, its structure shows some resemblance to the notorious Star Wars superweapon. Though microscopic, by protein standards it’s enormous: a sphere made out of many interlocking pieces.

    2
    The Death Star artificial protein. Institute for Protein Design

    “We’ve figured out a way to put these building blocks together at the right angles to form these very complex nanostructures,” Baker explains. He plans to stud the exterior with proteins from a whole suite of flu strains so that the immune system will learn to recognize them and be prepared to fend off future invaders. A single Death Star will carry 20 different strains of the influenza virus.

    Baker hopes this collection will cover the entire range of possible influenza mutation combinations. This all-in-one preview of present and future flu strains could replace annual shots: Get the Death Star vaccination, and you’ll already have the requisite antibodies in your bloodstream.

    As Baker bets on designer proteins to defeat influenza, others are betting on David Baker.

    After revolutionizing the study of proteins — molecules that perform crucial tasks in every cell of every natural organism — Baker is now engineering them from scratch to improve on nature. In late 2017, the Open Philanthropy Project gave his University of Washington Institute for Protein Design more than $10 million to develop the Death Star and support Rosetta, the software platform he conceived in the 1990s to discover how proteins are assembled. Rosetta has allowed Baker’s lab not only to advance basic science and pioneer new kinds of vaccines, but also to create drugs for genetic disorders, biosensors to detect toxins and enzymes to convert waste into biofuels.

    His team currently numbers about 80 grad students and postdocs, and Baker is in constant contact with all of them. He challenges their assumptions and tweaks their experiments while maintaining an egalitarian environment in which ideas may come from anyone. He calls his operation a “communal brain.” Over the past quarter-century, this brain has generated nearly 450 scientific papers.

    “David is literally creating a new field of chemistry right in front of our eyes,” says Raymond Deshaies, senior vice president for discovery research at the biotech company Amgen and former professor of biology at Caltech. “He’s had one first after another.”

    Nature’s Origami

    When Baker was studying philosophy at Harvard University, he took a biology class that taught him about the so-called “protein folding problem.” The year was 1983, and scientists were still trying to make sense of an experiment, carried out in the early ’60s by biochemist Christian Anfinsen, that revealed the fundamental building blocks of all life on Earth were more complex than anyone imagined.

    The experiment was relatively straightforward. Anfinsen mixed a sample of the protein ribonuclease — which breaks down RNA — with a denaturant, a chemical that deactivated it. Then he allowed the denaturant to evaporate. The protein started to function again as if nothing ever happened.

    What made this simple experiment so striking was the fact that the amino acids in protein molecules are folded in three-dimensional forms that make origami look like child’s play. When the denaturant unfolded Anfinsen’s ribonuclease, there were myriad ways it could refold, resulting in structures as different as an origami crane and a paper airplane. Much as the folds determine whether a piece of paper can fly across a room, only one fold pattern would result in functioning ribonuclease. So the puzzle was this: How do proteins “know” how to refold properly?

    “Anfinsen showed that the information for both structure and activity resided in the sequence of amino acids,” says University of California, Los Angeles, biochemist David Eisenberg, who has been researching protein folding since the 1960s. “There was a hope that it would be possible to use sequence information to get three-dimensional structural information. Well, that proved much more difficult than anticipated.”

    2
    Protein molecules play critical roles in every aspect of life. The way each protein folds determines its function, and the ways to fold are virtually limitless, as shown in this small selection of proteins visualized through the software platform Rosetta, born in Baker’s lab. Institute for Protein Design.

    Baker was interested enough in protein folding and other unsolved mysteries of biology to switch majors and apply to grad school. “I’d never worked in a lab before,” he recalls. He had only a vague notion of what biologists did on a daily basis, but he also sensed that the big questions in science, unlike philosophy, could actually be answered.

    Grad school plunged Baker into the tediousness and frustrations of benchwork, while also nurturing some of the qualities that would later distinguish him. He pursued his Ph.D. under Randy Schekman, who was studying how molecules move within cells, at the University of California, Berkeley. To aid in this research, students were assigned the task of dismantling living cells to observe their internal molecular traffic. Nearly half a dozen of them, frustrated by the assignment’s difficulty, had given up by the time Baker got the job.

    Baker decided to follow his instincts even though it meant going against Schekman’s instructions. Instead of attempting to keep the processes within a cell still functioning as he dissected it under his microscope, Baker concentrated on preserving cell structure. If the cell were a wristwatch, his approach would be equivalent to focusing on the relationship between gears, rather than trying to keep it ticking, while taking it apart.

    “He was completely obsessed,” recalls Deshaies, who was his labmate at the time (and one of the students who’d surrendered). Nobody could stop Baker, or dissuade him. He worked for months until he proved his approach was correct: Cell structure drove function, so maintaining its anatomy preserved the internal transportation network. Deshaies believes Baker’s methodological breakthrough was “at the core of Randy’s Nobel Prize,” awarded in 2013 for working out one of the fundamentals of cellular machinery.

    But Baker didn’t dwell on his achievement, or cell biology for that matter. By 1989, Ph.D. in hand, he’d headed across the Bay to the University of California, San Francisco, where he switched his focus to structural biology and biochemistry. There he built computer models to study the physical properties of the proteins he worked with at the bench. Anfinsen’s puzzle remained unsolved, and when Baker got his first faculty appointment at the University of Washington, he took up the protein-folding problem full time.

    From Baker’s perspective, this progression was perfectly natural: “I was getting to more and more fundamental problems.” Deshaies believes Baker’s tortuous path, from cells to atoms and from test tubes to computers, has been a factor in his success. “He just has greater breadth than most people. And you couldn’t do what he’s done without being somewhat of a polymath.”

    3
    Illustration above: National Science foundation. Illustrations below: Jay Smith

    Rosetta Milestone

    Every summer for more than a decade, scores of protein-folding experts convene at a resort in Washington’s Cascade Mountains for four days of hiking and shop talk. The only subject on the agenda: how to advance the software platform known as Rosetta.

    David Baker’s Rosetta@home project, a project running on BOINC software from UC Berkeley


    Rosetta@home BOINC project



    They call it Rosettacon.

    Rosetta has been the single most important tool in the quest to understand how proteins fold, and to design new proteins based on that knowledge. It is the link between Anfinsen’s ribonuclease experiment and Baker’s Death Star vaccine.

    When Baker arrived at the University of Washington in 1993, researchers knew that a protein’s function was determined by its structure, which was determined by the sequence of its amino acids. Just 20 different amino acids were known to provide all the raw ingredients. (Their particular order — specified by DNA — makes one protein fold into, say, a muscle fiber and another fold into a hormone.) Advances in X-ray crystallography, a technique for imaging molecular structure, had provided images of many proteins in all their folded splendor. Sequencing techniques had also improved, benefitting from the Human Genome Project as well as the exponential increase in raw computing power.

    “There’s a right time for things,” Baker says in retrospect. “To some extent, it’s just luck and historical circumstance. This was definitely the right time for this field.”

    Which is not to say that modeling proteins on a computer was a simple matter of plugging in the data. Proteins fold to their lowest free energy state: All of their amino acids must align in equilibrium. The trouble is that the equilibrium state is just one of hundreds of thousands of options — or millions, if the amino acid sequence is long. That’s far too many possibilities to test one at a time. Nature must have another way of operating, given that folding is almost instantaneous.

    Baker’s initial approach was to study what nature was doing. He broke apart proteins to see how individual pieces behaved, and he found that each fragment was fluctuating among many possible structures. “And then folding would occur when they all happened to be in the right geometry at the same time,” he says. Baker designed Rosetta to simulate this dance for any amino acid sequence.

    Baker wasn’t alone in trying to predict how proteins fold. In 1994, the protein research community organized a biennial competition called CASP (Critical Assessment of Protein Structure Prediction). Competitors were given the amino acid sequences of proteins and challenged to anticipate how they would fold.

    The first two contests were a flop. Structures that competitors number-crunched looked nothing like folded proteins, let alone the specific proteins they were meant to predict. Then everything changed in 1998.

    3
    Rosetta’s impressive computational power allows researchers to predict how proteins — long, complex chains of amino acids — will fold; the platform also helps them reverse engineer synthetic proteins to perform specific tasks in medicine and other fields. Brian Dalbalcon/UW Medicine.

    Function Follows Form

    That summer, Baker’s team received 20 sequences from CASP, a considerable number of proteins to model. But Baker was optimistic: Rosetta would transform protein-folding prediction from a parlor game into legitimate science.

    In addition to incorporating fresh insights from the bench, team members — using a janky collection of computers made of spare parts — found a way to run rough simulations tens of thousands of times to determine which fold combinations were most likely.

    They successfully predicted structures for 12 out of the 20 proteins. The predictions were the best yet, but still approximations of actual proteins. In essence, the picture was correct, but blurry.

    Improvements followed rapidly, with increased computing power contributing to higher-resolution models, as well as improved ability to predict the folding of longer amino acid chains. One major leap was the 2005 launch of Rosetta@Home, a screensaver that runs Rosetta on hundreds of thousands of networked personal computers whenever they’re not being used by their owners.

    Yet the most significant source of progress has been RosettaCommons, the community that has formed around Rosetta. Originating in Baker’s laboratory and growing with the ever-increasing number of University of Washington graduates — as well as their students and colleagues — it is Baker’s communal brain writ large.

    Dozens of labs continue to refine the software, adding insights from genetics and methods from machine learning. New ideas and applications are constantly emerging.

    4
    Protein (in green) enveloping fentanyl molecule. Bick et al. eLife 2017.

    The communal brain has answered Anfinsen’s big question — a protein’s specific amino acid alignment creates its unique folding structure — and is now posing even bigger ones.

    “I think the protein-folding problem is effectively solved,” Baker says. “We can’t necessarily predict every protein structure accurately, but we understand the principles.

    “There are so many things that proteins do in nature: light harvesting, energy storage, motion, computation,” he adds. “Proteins that just evolved by pure, blind chance can do all these amazing things. What happens if you actually design proteins intelligently?”

    De Novo Design

    Matthew Bick is trying to coax a protein into giving up its sugar habit for a full-blown fentanyl addiction. His computer screen shows a colorful image of ribbons and swirls representing the protein’s molecular structure. A sort of Technicolor Tinkertoy floats near the center, representing the opioid. “You see how it has really good packing?” he asks me, tracing the ribbons with his finger. “The protein kind of envelops the whole fentanyl molecule like a hot dog bun.”

    A postdoctoral fellow in Baker’s lab, Bick engineers protein biosensors using Rosetta. The project originated with the U.S. Department of Defense. “Back in 2002, Chechen rebels took a bunch of people hostage, and there was a standoff with the Russian government,” he says. The Russians released a gas, widely believed to contain a fentanyl derivative, that killed more than a hundred people. Since then, the Defense Department has been interested in simple ways to detect fentanyl in the environment in case it’s used for chemical warfare in the future.

    Proteins are ideal molecular sensors. In the natural world, they’ve evolved to bind to specific molecules like a lock and key. The body uses this system to identify substances in its environment. Scent is one example; specific volatiles from nutrients and toxins fit into dedicated proteins lining the nose, the first step in alerting the brain to their presence. With protein design, the lock can be engineered to order.

    For the fentanyl project, Bick instructed Rosetta to modify a protein with a natural affinity for the sugar xylotetraose. The software generated hundreds of thousands of designs, each representing a modification of the amino acid sequence predicted to envelop fentanyl instead of sugar molecules. An algorithm then selected the best several hundred options, which Bick evaluated by eye, eventually choosing 62 promising candidates. The protein on Bick’s screen was one of his favorites.

    “After this, we do the arduous work of testing designs in the lab,” Bick says.

    5
    Cassie Bryan, a senior fellow at Baker’s Institute for Protein Design at the University of Washington, checks on a tube of synthetic proteins. The proteins, not seen in nature, are in the process of thawing and being prepped to test how they perform. Brian Dalbalcon/UW Medicine.

    With another image, he reveals his results. All 62 contenders have been grown in yeast cells infused with synthetic genes that spur the yeasts’ own amino acids to produce the foreign proteins. The transgenic yeast cells have been exposed to fentanyl molecules tagged with a fluorescing chemical. By measuring the fluorescence — essentially shining ultraviolet light on the yeast cells to see how many glow with fentanyl — Bick can determine which candidates bind to the opioid with the greatest strength and consistency.

    Baker’s lab has already leveraged this research to make a practical environmental sensor. Modified to glow when fentanyl binds to the receptor site, Bick’s customized protein can now be grown in a common plant called thale cress. This transgenic weed can cover terrain where chemical weapons might get deployed, and then glow if the dangerous substances are present, providing an early warning system for soldiers and health workers.

    The concept can also be applied to other biohazards. For instance, Bick is now developing a sensor for aflatoxin, a residue of fungus that grows on grain, causing liver cancer when consumed by humans. He wants the sensor to be expressed in the grain itself, letting people know when their food is unsafe.

    But he’s going about things differently this time around. Instead of modifying an existing protein, he’s starting from scratch. “That way, we can control a lot of things better than in natural proteins,” he explains. His de novo protein can be much simpler, and have more predictable behavior, because it doesn’t carry many million years of evolutionary baggage.

    For Baker, de novo design represents the summit of his quarter-century quest. The latest advances in Rosetta allow him to work backward from a desired function to an appropriate structure to a suitable amino acid sequence. And he can use any amino acids at all — thousands of options, some already synthesized and others waiting to be designed — not only the 20 that are standard in nature for building proteins.

    Without the freedom of de novo protein design, Baker’s Death Star would never have gotten off the ground. His group is now also designing artificial viruses. Like natural viruses, these protein shells can inject genetic material into cells. But instead of infecting you with a pathogen, their imported DNA would patch dangerous inherited mutations. Other projects aim to take on diseases ranging from malaria to Alzheimer’s.

    In Baker’s presence, protein design no longer seems so extraordinary. Coming out of a brainstorming session — his third or fourth of the day — he pulls me aside and makes the case that his calling is essentially the destiny of our species.

    “All the proteins in the world today are the product of natural selection,” he tells me. “But the current world is quite a bit different than the world in which we evolved. We live much longer, so we have a whole new class of diseases. We put all these nasty chemicals into the environment. We have new needs for capturing energy.

    “Novel proteins could solve a lot of the problems that we face today,” he says, already moving to his next meeting. “The goal of protein design is to bring those into existence.”

    See the full article here .

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  • richardmitnick 3:20 pm on October 19, 2018 Permalink | Reply
    Tags: , , , Blazar PG 1553+113, , , Discover Magazine   

    From Discover Magazine: “In a First, Astronomers Find a Blazar That Cycles Every Two Years” 

    DiscoverMag

    From Discover Magazine

    October 19, 2018
    Chelsea Gohd

    1
    A visualization of the blazar being observed while emitting gamma rays. (Credit: Stefano Ciprini)

    Blazar Brightness

    After 10 years of observations, scientists have confirmed a two-year cycle in the gamma-ray brightness of a blazar, or a galaxy with supermassive black holes that consume mass and produce high-energy jets as a result. Blazars are the most energetic and luminous objects that we have identified so far in the known universe.

    “This is the first time that a gamma-ray period has been confirmed in an active galaxy,” Stefano Ciprini, a researcher at the INFN Tor Vergata division of the Italian Space Agency’s Space Science Data Center in Rome, said in a press statement. Gamma rays are some of the most energetic electromagnetic emissions, and powerful objects like blazars produce them in large quantities.

    Finding that the emissions increase and decrease in a predictable cycle, though, hints to researchers that there might be more than one supermassive black hole at the center of this galaxy.

    The confirmation, the first of its kind, could help to support new investigations and provide new insight into what really happens close to supermassive black holes.

    2
    An animation of emissions from the blazar showing how they vary predictably. (Credit: NASA)

    Exploring Black Holes

    One of the most exciting things about this work and this blazar, named PG 1553+113, is that scientists think that the galaxy may have a pair of supermassive black holes in its center, instead of just one. This could explain the cyclical nature of the blazar, the researchers say. One black hole would be emitting a jet of gamma rays and other material, and the other might be interfering with the stream as it orbits, causing the jet to wobble.

    In 2015, this research team found hints of this gamma-ray cycle inPG 1553+113. They suspected that this distant blazar might be producing the first observed years-long gamma-ray emission cycle. And, after a few more years of observations, the team has confirmed these previous inklings.

    “This result has been achieved after 10 years of continuous monitoring by Fermi’s Large Area Telescope (LAT),” Sara Cutini, a researcher at the Italian Institute for Nuclear Physics (INFN) in Perugia, said in the statement.

    A paper detailing this analysis and conclusions is in the works and the findings were announced yesterday (Oct. 17) at the Eighth International Fermi Symposium meeting in Baltimore.

    See the full article here .

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  • richardmitnick 2:29 pm on October 19, 2018 Permalink | Reply
    Tags: , , , , Discover Magazine, , Scientists Map Out 21 New Constellations, Using Gamma Rays   

    From Discover Magazine: “Using Gamma Rays, Scientists Map Out 21 New Constellations” 

    DiscoverMag

    From Discover Magazine

    October 19, 2018
    Chelsea Gohd

    1
    The Godzilla constellation in the gamma-ray sky — a new set of constellations based off of gamma-ray emissions observed with NASA’s Fermi Gamma-ray Space Telescope. (Credit: NASA)

    NASA/Fermi LAT


    NASA/Fermi Gamma Ray Space Telescope

    Gamma-Ray Sky

    For countless years, humans have gazed up at the sky and made sense of the stars by finding shapes in them — constellations of heroes, animals, and well-worn tales. Now, to celebrate the 10th mission year of NASA’s Fermi Gamma-ray Space Telescope, scientists have used the telescope to develop a new set of constellations that correspond with gamma-ray emissions [Future post].

    Gamma rays are the most powerful in the electromagnetic spectrum, and they’re typically only produced by very powerful objects. Supermassive black holes at the center of galaxies emit gamma rays, and gamma rays can also spring from explosive gamma-ray bursts, pulsars, the debris of supernova explosions, and more. The Fermi telescope has spent the last decade scanning the sky to compile list of gamma ray sources in the observable universe. That’s given them an array of points, similar to the stars we see shining in the visible spectrum.

    In what is known as the “gamma-ray sky,” scientists have devised constellations inspired by many of the same things that inspired the starlight constellations our ancestors gazed at.

    The “original” constellations primarily fall into three categories: myths and legends, meaningful topics and common creatures and items, NASA Goddard’s Elizabeth Ferrara, who led the constellation project, explained in a teleconference. The Fermi constellations from the gamma-ray sky are also derived from three categories: modern legends, team partners, and Fermi science. To make sure they didn’t look too much like stars, the team behind these constellations used artificial color to distinguish them.

    Familiar Shapes

    There are 21 Fermi constellations, including the Hulk (created from a gamma-ray mishap), Godzilla, the Starship Enterprise from “Star Trek: The Next Generation”, the TARDIS from “Doctor Who”, gamma-ray bursts, dark lightning, spider pulsars. Important landmarks from partner nations show up as well: Mt. Fuji for Japan, the Colosseum to represent Italy and more. The constellations even include a Saturn V rocket to represent Huntsville, Alabama where the gamma-ray burst monitor team is centered.

    2
    (Credit: NASA)
    The Godzilla constellation in the gamma-ray sky — a new set of constellations based off of gamma-ray emissions observed with NASA’s Fermi Gamma-ray Space Telescope. (Credit: NASA)
    Gamma-Ray Sky

    For countless years, humans have gazed up at the sky and made sense of the stars by finding shapes in them — constellations of heroes, animals, and well-worn tales. Now, to celebrate the 10th mission year of NASA’s Fermi Gamma-ray Space Telescope, scientists have used the telescope to develop a new set of constellations that correspond with gamma-ray emissions.

    Gamma rays are the most powerful in the electromagnetic spectrum, and they’re typically only produced by very powerful objects. Supermassive black holes at the center of galaxies emit gamma rays, and gamma rays can also spring from explosive gamma-ray bursts, pulsars, the debris of supernova explosions, and more. The Fermi telescope has spent the last decade scanning the sky to compile list of gamma ray sources in the observable universe. That’s given them an array of points, similar to the stars we see shining in the visible spectrum.

    In what is known as the “gamma-ray sky,” scientists have devised constellations inspired by many of the same things that inspired the starlight constellations our ancestors gazed at.

    The “original” constellations primarily fall into three categories: myths and legends, meaningful topics and common creatures and items, NASA Goddard’s Elizabeth Ferrara, who led the constellation project, explained in a teleconference. The Fermi constellations from the gamma-ray sky are also derived from three categories: modern legends, team partners, and Fermi science. To make sure they didn’t look too much like stars, the team behind these constellations used artificial color to distinguish them.

    Familiar Shapes

    There are 21 Fermi constellations, including the Hulk (created from a gamma-ray mishap), Godzilla, the Starship Enterprise from “Star Trek: The Next Generation”, the TARDIS from “Doctor Who”, gamma-ray bursts, dark lightning, spider pulsars. Important landmarks from partner nations show up as well: Mt. Fuji for Japan, the Colosseum to represent Italy and more. The constellations even include a Saturn V rocket to represent Huntsville, Alabama where the gamma-ray burst monitor team is centered.

    “The hope, of course, is to make the gamma-ray sky more acceptable,” Ferrara said. “By creating constellations that tie into themes that people already know and think about, we hope to bring gamma-ray science into their thoughts.”

    Ferrara and Daniel Kocevski, from NASA’s Marshall Space Flight Center, have developed an interactive webpage so that the public can easily engage with these constellations. The interactive site uses a map of the gamma-ray sky from Fermi and artwork from Aurore Simonnet, an illustrator at Sonoma State University in Rohnert Park, California.

    Users on the site can explore the gamma-ray sky themselves and learn about the name, artwork, and details behind each constellation.

    See the full article here .

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  • richardmitnick 3:05 pm on September 28, 2018 Permalink | Reply
    Tags: , , , Discover Magazine, Powerful Jets Found Shooting From An Incredibly Magnetic Neutron Star, Swift J0243.6+6124 (SW J0243)   

    From Discover Magazine: “Powerful Jets Found Shooting From An Incredibly Magnetic Neutron Star” 

    DiscoverMag

    From Discover Magazine

    September 28, 2018
    Jake Parks

    1
    A narrow beam shoots out matter at nearly the speed of light in this artist’s concept of the neutron star Swift J0243.6+6124, which is the first highly magnetic neutron star known to house such a powerful jet. (Credit: ICRAR/University of Amsterdam)

    For the first time, astronomers have witnessed a fast-moving jet of material shooting outward from a neutron star with an extremely powerful magnetic field — one that is some 10 trillion times stronger than the Sun’s. The surprising discovery not only caught researchers off guard, but is also forcing them to fundamentally rethink their current theories regarding how jets form throughout the cosmos.

    Intense Magnetism

    Astronomers have long been fascinated with neutron stars, which are the superdense cores left behind after a massive star explodes in spectacular fashion. These extreme stars are so compact that if our Sun were compressed to the density of a neutron star, it would only be about 10 miles wide (for comparison, the Sun is roughly 850,000 miles wide). With so much matter packed into such a tiny space, neutron stars have intense gravitational pulls near their surfaces that are only rivaled by black holes, which can lead to some pretty interesting effects.

    In a new study, published yesterday in the journal Nature, a team of researchers used a radio telescope called the Karl G. Jansky Very Large Array (VLA) to observe and analyze one bizarre neutron star named Swift J0243.6+6124 (SW J0243).

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    This object was was first discovered thanks to an unexpected and bright outburst that was captured by NASA’s Swift space telescope in October 2017.

    NASA Neil Gehrels Swift Observatory

    2
    The binary system Swift J0243.6+6124 is made up of a neutron star and a more massive companion star orbiting each other every 27 days. As the neutron star passes near its partner (as shown in this artist’s concept), it pulls material into a disk around it. (Credit: ICRAR/University of Amsterdam)

    By monitoring how the object’s X-ray and radio emissions evolved following the outburst, the researchers were able to determine the neutron star is likely stealing material from a massive, nearby companion star and condensing that material into a swirling disk called an accretion disk. In turn, interactions between the accretion disk and the neutron star’s magnetic field lines lead to the production of powerful jets at the neutron star’s poles, which spew out matter at nearly the speed of light.

    The fact that a neutron star is home to such jets is not a surprise in and of itself. “We’ve seen jets coming from all types of neutrons stars that are pulling material from their companions,” said lead author Jakob van den Eijnden of the University of Amsterdam in a press release. “[But] never before have we seen a jet coming from a neutron star with a very strong magnetic field.”

    Jet Theory

    According to current theory, neutron stars with extremely intense magnetic fields like SW J0243 should not be capable of producing such jets. Our working theories — backed by decades of observations — suggest that extremely strong magnetic fields should overpower and prevent the formation of jets around neutron stars. But according to van den Eijnden, “Our clear discovery of a jet in SW J0243 disproves that longstanding idea.”

    However, as the authors note in their paper, there is still much more work to be done. Before they are able to eliminate all other possible explanations for the apparent jets — which range from intense stellar winds to shock waves within the accretion disk — they need to gather more observational evidence to prove the jets really do exist.

    But, according to co-author Nathalie Degenaar, if their findings hold up (or more jets are observed around other strongly magnetized neutron stars) “This discovery not only means we have to revise our ideas about jets from such systems, but also opens up exciting new areas of research.”

    See the full article here .

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  • richardmitnick 8:14 pm on September 13, 2018 Permalink | Reply
    Tags: Discover Magazine, Previously it was thought that the orbits of both light and massive stellar objects are distributed [uniformly] around the supermassive black hole, , Thousands of Black Holes Form Disks in the Center of the Galaxy, Vector resonant relaxation, While black holes orbit in a disk less massive objects like stars form a more spherical distribution   

    From Discover Magazine: “Thousands of Black Holes Form Disks in the Center of the Galaxy” 

    DiscoverMag

    From Discover Magazine

    September 13, 2018
    Chelsea Gohd

    1
    In this artistic visualization, a supermassive black hole at a galaxy’s center shoots out radiation and high-speed winds. According to a new study, supermassive black holes at a galaxy’s center are surrounded by a disk of black holes and massive stars. (Credit: NASA/JPL-Caltech)

    At the center of most galaxies lie supermassive black holes. Their exceptional gravity pulls in thousands of stars and stellar mass black holes, or black holes formed when a massive star collapses due to gravity.

    By simulating how objects interact near the supermassive black holes in the center of galaxies, astrophysicists from Eötvös University in Hungary have shown, in a new study, that these black holes form a thick disk around a galaxy’s supermassive black hole.

    “Previously it was thought that the orbits of both light and massive stellar objects are distributed [uniformly] around the supermassive black hole,” Ákos Szölgyén, a researcher at Eötvös University who led the study, said in a statement, “we now understand that massive stars and black holes typically segregate into a disk.”

    4
    Eötvös University

    2
    An artist’s [now iconic] illustration of the black hole Cygnus X-1. New research shows that thick disks of black holes and massive stars likely form at the center of all galaxies, surrounding supermassive black holes. (Credit: NASA/CXC/M.Weiss)

    Swarm of Black Holes

    In their simulation, Szölgyén and his Ph.D. advisor, Bence Kocsis, incorporated something called vector resonant relaxation. It’s an effect that gravity has on objects orbiting a supermassive black hole. This effect grows over millions of years, making the orbital planes of these objects turn.

    Kocsis compared the effect and the behavior of the objects to the movement of bees, “Unlike a swarm of bees around a beehive, stars fly around in the galactic center in a more ordered way: along precessing elliptical trajectories, each confined to a plane, respectively,” he said in the statement. Kocsis continued, describing how the objects shift their orbits slowly over millions of years.

    This effect helped the astronomers see that while black holes orbit in a disk, less massive objects like stars form a more spherical distribution, Kocsis added in an email.

    Stars usually form in one of two ways at the centers of galaxies. Gas can condense into stars around the supermassive black hole. Or, alternatively, groups of stars called globular clusters can spin into the galaxy’s center, where they’re ripped into the building blocks of new stars by the supermassive black hole. “In both cases, we find a disk of black holes,” Kocsis noted.

    That means these black hole disks probably form in all galaxies.

    Black Hole Disks and Gravitational Waves

    According to Kocsis, this study could also help scientists better understand gravitational waves. As scientists have detected gravitational waves using LIGO and VIRGO, they’ve been surprised to see the rate of black hole mergers is much higher than they expected. “The big question, known as the ‘final AU problem’,” Kocsis explained, is how black holes might get to an AU (or astronomical unit, roughly the distance from the Earth to the sun) that drives them to merge.

    According to Kocsis, better understanding black hole disks could help answer this question because these dense environments “may lead to mergers more often.”

    This study was published in the journal Physical Review Letters.

    See the full article here .

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  • richardmitnick 5:15 pm on September 8, 2018 Permalink | Reply
    Tags: , Discover Magazine, QUEST-La Silla AGN Variability Survey, ,   

    From Discover Magazine: “Black Holes Flicker as They Stop Gorging Themselves on Matter” 

    DiscoverMag

    From Discover Magazine

    September 7, 2018
    Alison Klesman

    1
    This artistically enhanced image shows a Hubble Space Telescope view of the active galaxy Arp 220, which houses a feeding supermassive black hole at its center. (Credit: NASA/JPL-Caltech)

    NASA/ESA Hubble Telescope

    Black holes are by nature difficult to study directly. Because even light cannot escape these massive objects, astronomers must turn to other methods to spot and study them. While information is lost once it crosses a black hole’s event horizon, outside that boundary, it can still escape. A recent study, led by a graduate student in the Department of Astronomy of the Universidad de Chile, has now found that the amount of light emitted from around a black hole is determined by one thing, and one thing only: the rate at which matter is falling into the black hole.

    The research, published September 4 in The Astrophysical Journal, was aimed at determining the physical mechanism behind the variability observed from the active black holes at the centers of galaxies (known as active galactic nuclei, or AGN), which are supermassive black holes currently sucking in matter.

    In astronomy, this process is known as accretion. Such black holes have accretion disks, which are disks of matter swirling around them as it is funneled inward, like water going down a drain. Outside the event horizon, these disks shine brightly as the material inside is heated by friction, giving off visible light and even more energetic light, such as X-rays. These disks are also variable — astronomers aren’t exactly sure why, but the current understanding is that as clumps of matter interact in the disk or fall into the black hole, it causes changes in the light the disk emits.

    The team combined data from the Sloan Digital Sky Survey and the QUEST-La Silla AGN Variability Survey to combine physical properties —the mass and the accretion rate, or the speed at which a black hole is eating — of about 2,000 AGN with information about their variability.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    What they found was surprising: “Contrary to what was believed, the only important physical property to explain the amplitude of the variability is the AGN accretion rate,” said Paula Sánchez-Sáez, the student who led the study and first author of the paper, in a press release.

    Out With The Old

    Why is this surprising? “The results obtained in this study challenge the old paradigm that the amplitude of the AGN variability depended mainly on the luminosity of the AGN,” Sánchez-Sáez said. What this means is that previously, astronomers assumed that more luminous (brighter) AGN varied more, while less luminous (dimmer) AGN varied less. This study instead discovered that the rate at which a black hole is eating is the only thing that affects the amount its light varies, regardless of whether it is bright or dim.

    But the challenge to previous thinking makes sense, Sánchez-Sáez said, because in the past, it’s been difficult to accurately measure a black hole’s mass, and thus its accretion rate. Only with newer data provided by large surveys can astronomers begin to build up the numbers they need to test their assumptions.

    With Black Holes, Less is More

    Furthermore, the study revealed a relationship that may seem backwards: “What we detect is that the less they [black holes] swallow, the more they vary,” said Paulina Lira of the Universidad de Chile and the CATA Center for Excellence in Astrophysics, and a co-author on the paper. In scientific terms, the amplitude (amount) of variability is inversely proportional to the accretion rate, or the amount of food a black hole is consuming at any given time.

    This initial study was based on variability information from the QUEST-La Silla AGN Variability Survey spanning about five years. Now, the researchers are looking to study the variability of these objects in greater detail, for which they’ll need more data. That means staring at these AGN for longer periods of time — at least 10 years or more. For that, they’ll need to wait for future surveys, such as those proposed with the Large Synoptic Survey Telescope, which is expected to reach full science operations by 2023. This will “extend our light curves to an order of 20 years,” said Lira, providing an even more accurate picture of the black hole’s behavior over longer periods of time.

    See the full article here .

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  • richardmitnick 11:41 am on September 1, 2018 Permalink | Reply
    Tags: Amending the name of the Hubble Law to the Hubble-Lemaître Law, Arno Penzias and Robert Wilson with the Holmdel horn antenna first caught the faint echo of the Big Bang, , , , Big Bang Vote: IAU Debates Who Gets Credit For Expanding Universe, Discover Magazine, Edwin Hubble, , , , Saul Perlmutter shared the 2006 Shaw Prize in Astronomy the 2011 Nobel Prize in Physics and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess for providing eviden   

    From Discover Magazine: “Big Bang Vote: IAU Debates Who Gets Credit For Expanding Universe” 

    DiscoverMag

    From Discover Magazine

    August 31, 2018
    Krzysztof Bolejko

    1
    Captured: approximately 15,000 galaxies (12,000 of which are star-forming) widely distributed in time and space. (Credit: NASA, ESA, P. Oesch (University of Geneva), and M. Montes (University of New South Wales))

    Astronomers are engaged in a lively debate over plans to rename one of the laws of physics.

    It emerged overnight in Vienna at the 30th Meeting of the International Astronomical Union (IAU), in Vienna, where members of the general assembly considered a resolution on amending the name of the Hubble Law to the Hubble-Lemaître Law.

    The resolution aims to credit the work of the Belgian astronomer Georges Lemaître and his contribution – along with the American astronomer Edwin Hubble – to our understanding of the expansion of the universe.

    While most (but not all) members at the meeting were in favor of the resolution, it was decided to give all members of the International Astronomical Union a chance to vote. Subsequently, voting was downgraded to a straw vote and the resolution will formally be voted on by an electronic vote at a later date.

    Giving all members a say via electronic voting was introduced following criticism of the IAU’s 2006 general assembly when a resolution to define a planet – that saw Pluto relegated to a dwarf-planet – was approved.

    But changing the name of the Hubble Law raises the questions of who should be honored in the naming of the laws of physics, and whether the IAU should be involved in any decision.

    Discovering The Big Bang

    The expansion of the universe was one of the most mind-blowing discoveries of the 20th century.

    Expansion here means that the distance between galaxies in general increases with time, and it increases uniformly. It does not matter where you are and in which direction you look at, you still see a universe that is expanding.

    When you really try to imagine all of this, you may end up with a headspin or even worse, as satirically depicted by Woody Allen in his movie Annie Hall.

    The rate at which the universe is currently expanding is described by the Hubble Law, named after Edwin Hubble who in 1929 published an article reporting that astronomical data signify the expansion of the universe.

    Arno Penzias and Robert Wilson, AT&T, Holmdel, NJ USA, with the Holmdel horn antenna, first caught the faint echo of the Big Bang

    Saul Perlmutter shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating.

    Hubble Was Not The First

    In 1927, Georges Lemaître had already published an article on the expansion of the universe. His article was written in French and published in a Belgian journal.

    Lemaître presented a theoretical foundation for the expansion of the universe, and used the astronomical data (the very same data that Hubble used in his 1929 article) to infer the rate at which the universe is expanding.

    In 1928 the American mathematician and physicist Howard Robertson published an article in Philosophical Magazine and Journal of Science, where he derived the formula for the expansion of the universe and inferred the rate of expansion from the same data that were used by Lemaître (a year before) and Hubble (a year after).

    Robertson did not know about Lemaître’s work. Given the limited popularity of the Belgian journal in which Lemaître’s paper appeared and the French language used, it is argued his remarkable discovery went largely unnoticed at the time by the astronomical community.

    But the findings published by Hubble in 1929 were most likely influenced by Lemaître. In July 1928, Lemaître and Hubble met at the 3rd meeting of the International Astronomical Union, in Leiden. During the meeting they discussed the astronomical evidence suggesting the expansion of the universe.

    The Expanding Universe

    In January 1930 at the meeting of the Royal Astronomical Society in London, the English astronomer, physicist and mathematician Arthur Eddington raised the problem of the expansion of the universe and the lack of any theory that would satisfactory explain this phenomenon.

    When Lemaître found about this, he wrote to Eddington to remind him about his 1927 paper, where he laid theoretical foundation for the expansion of the universe. Eddington invited Lemaître to republish the translation of the paper in Monthly Notices of the Royal Astronomical Society.

    In the meantime, Hubble and the American astronomer Milton Humason published new results on the expansion of the universe in The Astrophysical Journal. This time the sample was larger and reaching regions more than ten times greater than before.

    These new measurements made prior measurements of the expansion of the universe obsolete. Thus, when working on the translation, Lemaître removed from his article the paragraphs where he estimated the rate of the expansion of the universe.

    As a result of this change, for people not familiar with the previous papers by Lemaître or Robertson, it looked like it was Hubble who was the first one to discover the expansion of the universe.

    Lemaître was apparently not concerned with with establishing priority for his original discovery. Consequently, the formula that describes the present-day expansion rate bears the name of Hubble.

    The resolution of the executive committee of the IAU wants to change the name to the Hubble-Lemaître Law, to honour Lemaître and acknowledge his part in the discovery.

    Who Names The Stars?

    The IAU was founded in 1919 and one of its activities is to standardise the naming of celestial objects and their definitions: from small asteroids, to planets and constellations.

    The IAU comprises of Individual Members (more than 12,000 people from 101 countries) and National Members (79 different academies of science or national astronomical societies). The decisions made by IAU do not have any legislative power, but it does say:

    The names approved by the IAU represent the consensus of professional astronomers around the world and national science academies, who as “Individual Members” and “National Members”, respectively, adhere to the guidelines of the International Astronomical Union.

    It is thus reasonable to expect that if the resolution is passed then with time the new name will become more widely used.

    IAU Vote

    This resolution has serious implications. It seeks to acknowledge Lemaître for his involvement in one of the most fundamental discoveries on the behavior of our universe. At the same time, the resolution may set a precedent for future actions.

    Will this initiate further changes? Will other disciplines follow the example set by astronomers?

    Science is full of laws, effects, equations and constants that in many cases do not bear the name of their rightful discoverers. Some people worry that giving the due credit in all of such cases will cost a lot of effort and time.

    Others will welcome this precedent and eagerly await when, for example, Henrietta Swan Leavitt will finally be properly acknowledged for the discovery of the period-luminosity relation.

    For now, we have to wait for the result of the electronic voting.

    See the full article here .

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  • richardmitnick 7:03 am on August 20, 2018 Permalink | Reply
    Tags: , Discover Magazine, ,   

    From Discover Magazine- “Wilderness vs. Monitoring: The Controversy of a New Seismic Network at Glacier Peak” 

    DiscoverMag

    From Discover Magazine

    August 19, 2018
    Erik Klemetti

    1
    Glacier Peak in Washington. Wikimedia Commons.

    One of the most potentially dangerous volcanoes in the Cascades is Glacier Peak in Washington. It produced the one of the largest eruptions in the past 20,000 years in this volcanic range that spans from British Columbia to California. Multiple eruptions around 13,500 years ago spread ash all the way into Montana. Over the last 2,000 years, there have been multiple explosive eruptions that have impacted what became Washington state and beyond. Put on top of that the many glaciers on the slopes of Glacier Peak that could help form volcanic mudflows (lahars) during a new eruption, and you can see that Glacier Peak is a real threat.

    Yet, even with this hazard posed by the volcano, there is very little in the way of monitoring equipment on the volcano. Currently, there is a lone seismometer on the volcano to measure earthquakes, one of the most important pieces of information needed to monitor volcanoes.

    2
    The lone seismometer at Glacier Peak. USGS. https://volcanoes.usgs.gov/volcanoes/glacier_peak/monitoring_earthquakes.html

    A single seismometer is better than no seismometer, but it can only give us so much information. Without a network of at least 3 seismometers (a“seismic network”), we can really only measure if earthquakes are occurring at the volcano and not exactly where and how far beneath the volcano the temblors are happening. This is what is installed at a truly restless volcano like Mount St. Helens.

    These two pieces of information — location and depth — are vital for understanding what might be happening at the Glacier Peak if any earthquake swarm were to happen. Otherwise, we might have difficulty differentiating between earthquakes happening due to fault motion near the volcano or shallow changes in the hydrothermal system in the volcano rather than magma moving into the volcano from deep below.

    So, it might seem to be a no-brainer that new USGS seismic stations should be set up on Glacier Peak. However, that’s where things get messy. Glacier Peak is within designated US Forest Service Wilderness area, so modification and use of the land are very tightly regulated and restricted. This is rightly so — we need to protect our wilderness from encroaching development or resource exploitation by people who don’t value a wild America.

    The problem becomes that a seismic station, a fairly small installation that might have a 3 by 3 meter footprint, still disrupts wilderness in order to build the station as it requires the seismometer to be buried and secured to a stable platform (like rock or poured concrete). Additionally, although many stations are solar, they do require back-up batteries that need to be changed … and if there are no roads and trails in the wilderness, getting material to the station is next to impossible.

    In order to perform repairs and resupply batteries, helicopters will be needed, so ideally, a helicopter pad near the seismic stations is needed for safe operation. This is a bigger deal as a helicopter pad might take up a few hundred square meters. It is this sort of disruption that has the Wilderness Watch speaking out against the installation of new seismic stations at Glacier Peak.

    See the full article here .

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

    Please help promote STEM in your local schools.

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