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  • richardmitnick 3:10 pm on January 21, 2020 Permalink | Reply
    Tags: , , , , , Impact craters, NYT   

    From The New York Times: “Earth’s Oldest Asteroid Impact Found in Australia” 

    From The New York Times

    Jan. 21, 2020
    Katherine Kornei

    The cataclysm, which occurred roughly 2.2 billion years ago, might have catapulted the planet out of an ice age.

    An outcrop of impact melt rock on Barlangi Hill in the Yarrabubba crater in Western Australia, the site of an asteroid collision more than 2 billion years old.Credit.Timmons Erickson

    Earth is constantly being pummeled by space rocks. Several tons rain down on the planet each day in the form of dust. And larger strikes have created more visible features, including giant craters.

    Artist’s reconstruction of Chicxulub crater soon after impact, 66 million years ago.
    This strike was the one responsible for the extinction of the dinosaurs.

    But which of our planet’s extraterrestrial scars is the oldest?

    Researchers reported on Tuesday in Nature Communications that they have pinpointed it, in Western Australia. It was caused by an impact more than 2.2 billion years ago.

    Intriguingly, that timing roughly coincides with the end of one of our planet’s ice ages. An impact in the ice would have liberated an enormous amount of water vapor, the researchers suggest, perhaps enough to alter Earth’s climate and catapult the planet out of widespread glaciation.

    The Yarrabubba impact structure, about a day’s drive northeast of Perth, isn’t much to look at today. The original crater, believed to have been roughly 40 miles in diameter, is long gone.

    “There’s no topography that rises up,” said Aaron Cavosie, a planetary scientist at Curtin University in Perth and a member of the research team.

    That’s because the combined effects of wind, rain, glaciation and plate tectonics have scoured several miles off the surface of the planet, effectively erasing the crater. The extent of erosion suggests that the impact structure is very, very old.

    Existing clues yield “a pretty giant” age range of about a billion and a half years, said Timmons Erickson, a geochronologist at NASA Johnson Space Center in Houston and the study’s lead author. But Dr. Erickson knew that it was possible to do far better, by reading the tiny geological clocks that hide within rocks.

    In 2014, Dr. Erickson collected roughly 200 pounds of granitic rocks from Yarrabubba. Back in the laboratory, he and his colleagues placed the rocks in water and added 120,000 volts of electricity. That jolt broke the rocks into sand-size grains. The scientists were looking for grains of zircon and monazite, tough minerals that survive for billions of years and, crucially, incorporate uranium and thorium atoms into their crystalline structure.

    Uranium and thorium decay, in a steady dribble over billions of years, into lead. But the searing temperatures of an impact — thousands of degrees Fahrenheit — cause zircon and monazite to recrystallize, a process that drives out lead.

    “It’s kind of like cleaning house,” Dr. Cavosie said. “Recrystallization is a bond-breaking process that kicks out the pre-existing lead and thus resets the clock.”

    As a result, the relative amounts of uranium, thorium and lead in recrystallized zircon or monazite can be used to calculate how long ago an impact occurred.

    Based on measurements of 39 zircon and monazite crystals, Dr. Erickson and his team calculated that the Yarrabubba impact occurred 2.229 billion years ago, with an uncertainty of 5 million years. The next-oldest impact structure, Vredefort Dome in South Africa, is over 200 million years younger.

    A grain of zircon analyzed by Dr. Erickson and his colleagues, showing recrystallization textures from the impact.Credit…Erickson et al., Nature Communications 2020

    The age of the Yarrabubba impact structure happens to line up with the end of an ice age, which makes for a compelling coincidence, Dr. Erickson said: “Would an impact event like Yarrabubba be enough to terminate a glacial time in Earth’s history?”

    To help answer that question, the scientists modeled the effects of a roughly four-mile-wide impact object striking ice sheets of different thicknesses. They found that more than 100 billion tons of water vapor would have been jetted into the upper atmosphere.

    Water vapor is a potent greenhouse gas; suddenly having much more of it aloft could have triggered a warming that ended an ice age, the team suggested. That idea still needs to be tested with climate models, the researchers noted.

    Christian Koeberl, a geochemist at the University of Vienna and not involved in the research, agreed. Inferring what might have happened to Earth’s ancient climate is “where things get a lot more speculative,” he said. “We just don’t know the answer to that yet.”

    See the full article here .


    Please help promote STEM in your local schools.

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  • richardmitnick 5:48 pm on January 17, 2020 Permalink | Reply
    Tags: "At the Bottom of the Sea, , , Eight days after being deposited another alligator’s carcass was completely missing., NYT, , They Wait to Feast on Alligators"   

    From The New York Times: “At the Bottom of the Sea, They Wait to Feast on Alligators” 

    From The New York Times

    Jan. 17, 2020
    Asher Elbein

    Early last year, a team of researchers dropped three alligator carcasses over a mile deep into the Gulf of Mexico. The goal was to see what would turn up to eat them.

    Stephen Jessop/Alamy

    When dead whales and big logs fall to the bottom of the gulf, “there’s a whole host of species found on them that aren’t found anywhere else in the ocean,” said Craig McClain, a deep-sea biologist in Louisiana.

    The crocodile lineage dates to the Mesozoic Era, when the seas teemed with enormous marine reptiles. When those reptiles died, fossils show that marine scavengers happily devoured them [Biology Letters].

    So Dr. McClain and his team hypothesized that unique ocean creatures might be waiting for crocodyliform meals.

    “We wondered if we did alligator falls, if we’d recover species that haven’t been previously known to science — relics and refugees from a time when marine reptiles dominated the ocean,” he said. “Are we going to be able to uncover an ancient fauna?”

    The research, published last month in PLOS ONE, didn’t just turn up a new species that thrives on alligator bones, but also revealed surprises about the food web deep beneath the Gulf of Mexico, including how carbon from Earth’s surface gets recycled in the oceans.

    Usually, Dr. McClain’s lab studies how deep-sea creatures feed on trees swept into the Mississippi Delta. But they began wondering what happened to alligators.

    “There were three swimming behind my house in the harbor,” Dr. McClain said. “That got my lab thinking about alligators in general as potential food falls.”

    Alligators are found in coastal habitats from Texas to South Carolina, and occasionally venture into saltwater. When they die, some must sink into the deep ocean.

    Because alligators are protected in Louisiana, Dr. McClain’s team worked with state officials to acquire three euthanized alligators. They selected three sites around the undersea Mississippi Canyon, and lowered each carcass from the ship on a basket, or “benthic elevator.”

    The team left the alligators weighted down in the abyssal mud. When they sent a remotely operated vehicle back a day later to check one of the carcasses, they got a shock.

    Dr. McClain and his colleagues had guessed that the alligators’ tough hides would make it difficult — perhaps impossible — for undersea scavengers to devour them. But the carcass was swarming with giant isopods, a football-sized species of scavenging crustacean, which had gotten around the alligator’s armor by chewing through softer spots under the armpit.

    That wasn’t the only surprise. Eight days after being deposited, another alligator’s carcass was completely missing. Dr. McClain’s team initially thought they’d returned to the wrong site, until they found drag marks. The carcass’s 45-pound weight was 30 feet away, the rope severed.

    “It was completely dumbfounding to us,” Dr. McClain said, adding that the alligator must have been carried off by a sixgill or Greenland shark.

    “Those are the only two sharks that reach substantial enough lengths and live deep enough in the Gulf of Mexico,” he said.

    The last alligator was swarming with scavengers as well. Fifty-one days after its placement, it had been picked completely clean. The bones were covered in a species of Osedax “zombie worms.”

    Other Osedax bore into the bones of fallen whales, but these worms are the first of their kind known in the Gulf of Mexico, Dr. McClain said, and represent a species new to science.

    Additional research could prove whether these zombie worms are a Mesozoic-era holdover that specializes in eating reptiles that die in the ocean. For now, the study potentially reveals something about alligators’ role in feeding other marine life.

    The ocean bottom gets no sunlight, preventing the photosynthesis that sustains most ecosystems. So animals living in undersea deserts depend on carbon from decaying organisms from above.

    “What we find really interesting is that alligators can be a food source,” Dr. McClain said, “and a food source that’s quickly accessed and can enter into the deep-sea food web a number of different ways. Isopods. Worms. Sharks.”

    If an alligator falls in the deep ocean, in other words, it does make a sound. A dinner bell.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 2:19 pm on January 14, 2020 Permalink | Reply
    Tags: "Have Dark Forces Been Messing With the Cosmos?", Alan Guth MIT "Inflation", , , , , CMB per Planck, , , , Discrepancy in how fast the niverse is expanding., Edwin Hubble in 1929 discovers the Universe is Expanding, , NYT, Saul Perlmutter [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronom; the 2011 Nobel Prize in Physics; and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt ,   

    From The New York Times: “Have Dark Forces Been Messing With the Cosmos?” 

    From The New York Times

    Feb. 25, 2019 [Sorry, missed the first time around. Picked up from another article found today by Dennis Overbye]
    Dennis Overbye

    Brian Stauffer

    There was, you might say, a disturbance in the Force.

    Long, long ago, when the universe was only about 100,000 years old — a buzzing, expanding mass of particles and radiation — a strange new energy field switched on. That energy suffused space with a kind of cosmic antigravity, delivering a not-so-gentle boost to the expansion of the universe.

    Then, after another 100,000 years or so, the new field simply winked off, leaving no trace other than a speeded-up universe.

    So goes the strange-sounding story being promulgated by a handful of astronomers from Johns Hopkins University. In a bold and speculative leap into the past, the team has posited the existence of this field to explain an astronomical puzzle: the universe seems to be expanding faster than it should be.

    The cosmos is expanding only about 9 percent more quickly than theory prescribes. But this slight-sounding discrepancy has intrigued astronomers, who think it might be revealing something new about the universe.

    And so, for the last couple of years, they have been gathering in workshops and conferences to search for a mistake or loophole in their previous measurements and calculations, so far to no avail.

    “If we’re going to be serious about cosmology, this is the kind of thing we have to be able to take seriously,” said Lisa Randall, a Harvard theorist who has been pondering the problem.

    At a recent meeting in Chicago, Josh Frieman, a theorist at the Fermi National Accelerator Laboratory [FNAL] in Batavia, Ill., asked: “At what point do we claim the discovery of new physics?”

    Now ideas are popping up. Some researchers say the problem could be solved by inferring the existence of previously unknown subatomic particles. Others, such as the Johns Hopkins group, are invoking new kinds of energy fields.

    Adding to the confusion, there already is a force field — called dark energy — making the universe expand faster.

    Dark Energy Survey

    Dark Energy Camera [DECam], built at FNAL

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

    Timeline of the Inflationary Universe WMAP

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

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

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

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

    And a new, controversial report suggests that this dark energy might be getting stronger and denser, leading to a future in which atoms are ripped apart and time ends.

    Thus far, there is no evidence for most of these ideas. If any turn out to be right, scientists may have to rewrite the story of the origin, history and, perhaps, fate of the universe.

    Or it could all be a mistake. Astronomers have rigorous methods to estimate the effects of statistical noise and other random errors on their results; not so for the unexamined biases called systematic errors.

    As Wendy L. Freedman, of the University of Chicago, said at the Chicago meeting, “The unknown systematic is what gets you in the end.”

    Edwin Hubble looking through a 100-inch Hooker telescope at Mount Wilson in Southern California, 1929 discovers the Universe is Expanding

    Edwin Hubble in 1949, two decades after he discovered that the universe is expanding.Credit…Boyer/Roger Viollet, via Getty Images (credit: Emilio Segre Visual Archives/AIP/SPL)

    Hubble trouble

    Generations of great astronomers have come to grief trying to measure the universe. At issue is a number called the Hubble constant, named after Edwin Hubble, the Mount Wilson astronomer who in 1929 discovered that the universe is expanding.

    As space expands, it carries galaxies away from each other like the raisins in a rising cake. The farther apart two galaxies are, the faster they will fly away from each other. The Hubble constant simply says by how much.

    But to calibrate the Hubble constant, astronomers depend on so-called standard candles: objects, such as supernova explosions and certain variable stars, whose distances can be estimated by luminosity or some other feature. This is where the arguing begins.

    Standard Candles to measure age and distance of the universe from supernovae. NASA

    Until a few decades ago, astronomers could not agree on the value of the Hubble constant within a factor of two: either 50 or 100 kilometers per second per megaparsec. (A megaparsec is 3.26 million light years.)

    But in 2001, a team using the Hubble Space Telescope, and led by Dr. Freedman, reported a value of 72. For every megaparsec farther away from us that a galaxy is, it is moving 72 kilometers per second faster.

    More recent efforts by Adam G. Riess [The Astrophysical Journal], of Johns Hopkins and the Space Telescope Science Institute, and others have obtained similar numbers, and astronomers now say they have narrowed the uncertainty in the Hubble constant to just 2.4 percent.

    But new precision has brought new trouble. These results are so good that they now disagree with results from the European Planck spacecraft, which predict a Hubble constant of 67.

    The discrepancy — 9 percent — sounds fatal but may not be, astronomers contend, because Planck and human astronomers do very different kinds of observations.

    Planck is considered the gold standard of cosmology. It spent four years studying the cosmic bath of microwaves [CMB] left over from the end of the Big Bang, when the universe was just 380,000 years old.

    CMB per ESA/Planck

    ESA/Planck 2009 to 2013

    But it did not measure the Hubble constant directly. Rather, the Planck group derived the value of the constant, and other cosmic parameters, from a mathematical model largely based on those microwaves.

    In short, Planck’s Hubble constant is based on a cosmic baby picture. In contrast, the classical astronomical value is derived from what cosmologists modestly call “local measurements,” a few billion light-years deep into a middle-aged universe.

    What if that baby picture left out or obscured some important feature of the universe?

    ‘Cosmological Whac-a-Mole’

    And so cosmologists are off to the game that Lloyd Knox, an astrophysicist from the University of California, Davis, called “cosmological Whac-a-Mole” at the recent Chicago meeting: attempting to fix the model of the early universe, to make it expand a little faster without breaking what the model already does well.

    One approach, some astrophysicists suggest, is to add more species of lightweight subatomic particles, such as the ghostlike neutrinos, to the early universe. (Physicists already recognize three kinds of neutrinos, and argue whether there is evidence for a fourth variety.) These would give the universe more room to stash energy, in the same way that more drawers in your dresser allow you to own more pairs of socks. Thus invigorated, the universe would expand faster, according to the Big Bang math, and hopefully not mess up the microwave baby picture.

    A more drastic approach, from the Johns Hopkins group, invokes fields of exotic anti-gravitational energy. The idea exploits an aspect of string theory, the putative but unproven “theory of everything” that posits that the elementary constituents of reality are very tiny, wriggling strings.

    String theory suggests that space could be laced with exotic energy fields associated with lightweight particles or forces yet undiscovered. Those fields, collectively called quintessence, could act in opposition to gravity, and could change over time — popping up, decaying or altering their effect, switching from repulsive to attractive.

    The team focused in particular on the effects of fields associated with hypothetical particles called axions. Had one such field arisen when the universe was about 100,000 years old, it could have produced just the right amount of energy to fix the Hubble discrepancy, the team reported in a paper late last year. They refer to this theoretical force as “early dark energy.”

    “I was surprised how it came out,” said Marc Kamionkowski, a Johns Hopkins cosmologist who was part of the study. “This works.”

    The jury is still out. Dr. Riess said that the idea seems to work, which is not to say that he agrees with it, or that it is right. Nature, manifest in future observations, will have the final say.

    Dr. Knox called the Johns Hopkins paper “an existence proof” that the Hubble problem could be solved. “I think that’s new,” he said.

    Dr. Randall, however, has taken issue with aspects of the Johns Hopkins calculations. She and a trio of Harvard postdocs are working on a similar idea that she says works as well and is mathematically consistent. “It’s novel and very cool,” Dr. Randall said.

    So far, the smart money is still on cosmic confusion. Michael Turner, a veteran cosmologist at the University of Chicago and the organizer of a recent airing of the Hubble tensions, said, “Indeed, all of this is going over all of our heads. We are confused and hoping that the confusion will lead to something good!”

    Doomsday? Nah, nevermind

    Early dark energy appeals to some cosmologists because it hints at a link to, or between, two mysterious episodes in the history of the universe. As Dr. Riess said, “This is not the first time the universe has been expanding too fast.”

    The first episode occurred when the universe was less than a trillionth of a trillionth of a second old. At that moment, cosmologists surmise, a violent ballooning propelled the Big Bang; in a fraction of a trillionth of a second, this event — named “inflation” by the cosmologist Alan Guth, of M.I.T. — smoothed and flattened the initial chaos into the more orderly universe observed today.


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

    HPHS Owls

    Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes
    Alex Mittelmann, Coldcreation

    Alan Guth’s notes:

    Alan Guth’s original notes on inflation

    Nobody knows what drove inflation.

    The second episode is unfolding today: cosmic expansion is speeding up. But why? The issue came to light in 1998, when two competing teams of astronomers asked whether the collective gravity of the galaxies might be slowing the expansion enough to one day drag everything together into a Big Crunch.

    To great surprise, they discovered the opposite: the expansion was accelerating under the influence of an anti-gravitational force later called dark energy. The two teams won a Nobel Prize.

    Saul Perlmutter [The Supernova Cosmology Project] 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 [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    Dark energy comprises 70 percent of the mass-energy of the universe. And, spookily, it behaves very much like a fudge factor known as the cosmological constant, a cosmic repulsive force that Einstein inserted in his equations a century ago thinking it would keep the universe from collapsing under its own weight. He later abandoned the idea, perhaps too soon.

    Under the influence of dark energy, the cosmos is now doubling in size every 10 billion years — to what end, nobody knows.

    Early dark energy, the force invoked by the Johns Hopkins group, might represent a third episode of antigravity taking over the universe and speeding it up. Perhaps all three episodes are different manifestations of the same underlying tendency of the universe to go rogue and speed up occasionally. In an email, Dr. Riess said, “Maybe the universe does this from time-to-time?”

    If so, it would mean that the current manifestation of dark energy is not Einstein’s constant after all. It might wink off one day. That would relieve astronomers, and everybody else, of an existential nightmare regarding the future of the universe. If dark energy remains constant, everything outside our galaxy eventually will be moving away from us faster than the speed of light, and will no longer be visible. The universe will become lifeless and utterly dark.

    But if dark energy is temporary — if one day it switches off — cosmologists and metaphysicians can all go back to contemplating a sensible tomorrow.

    “An appealing feature of this is that there might be a future for humanity,” said Scott Dodelson, a theorist at Carnegie Mellon who has explored similar scenarios.

    The phantom cosmos

    But the future is still up for grabs.

    Far from switching off, the dark energy currently in the universe actually has increased over cosmic time, according to a recent report in Nature Astronomy. If this keeps up, the universe could end one day in what astronomers call the Big Rip, with atoms and elementary particles torn asunder — perhaps the ultimate cosmic catastrophe.

    This dire scenario emerges from the work of Guido Risaliti, of the University of Florence in Italy, and Elisabeta Lusso, of Durham University in England. For the last four years, they have plumbed the deep history of the universe, using violent, faraway cataclysms called quasars as distance markers.

    Quasars arise from supermassive black holes at the centers of galaxies; they are the brightest objects in nature, and can be seen clear across the universe. As standard candles, quasars aren’t ideal because their masses vary widely. Nevertheless, the researchers identified some regularities in the emissions from quasars, allowing the history of the cosmos to be traced back nearly 12 billion years. The team found that the rate of cosmic expansion deviated from expectations over that time span.

    One interpretation of the results is that dark energy is not constant after all, but is changing, growing denser and thus stronger over cosmic time. It so happens that this increase in dark energy also would be just enough to resolve the discrepancy in measurements of the Hubble constant.

    The bad news is that, if this model is right, dark energy may be in a particularly virulent and — most physicists say — implausible form called phantom energy. Its existence would imply that things can lose energy by speeding up, for instance. Robert Caldwell, a Dartmouth physicist, has referred to it as “bad news stuff.”

    As the universe expands, the push from phantom energy would grow without bounds, eventually overcoming gravity and tearing apart first Earth, then atoms.

    The Hubble-constant community responded to the new report with caution. “If it holds up, this is a very interesting result,” said Dr. Freedman.

    Astronomers have been trying to take the measure of this dark energy for two decades. Two space missions — the European Space Agency’s Euclid and NASA’s Wfirst — have been designed to study dark energy and hopefully deliver definitive answers in the coming decade. The fate of the universe is at stake.

    ESA/Euclid spacecraft depiction


    In the meantime, everything, including phantom energy, is up for consideration, according to Dr. Riess.

    “In a list of possible solutions to the tension via new physics, mentioning weird dark energy like this would seem appropriate,” he wrote in an email. “Heck, at least their dark energy goes in the right direction to solve the tension. It could have gone the other way and made it worse!”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 1:07 pm on January 14, 2020 Permalink | Reply
    Tags: A pursuit that stretches from underground particle colliders to orbiting telescopes with all manner of ground-based observatories in between., , , , , , , , NYT, , The astronomer missed her Nobel Prize [in my view a crime of old white men], ,   

    From The New York Times: Women in STEM-“Vera Rubin Gets a Telescope of Her Own” 

    From The New York Times

    Jan. 11, 2020
    Dennis Overbye

    The astronomer missed her Nobel Prize [in my view a crime of old white men]. But she now has a whole new observatory to her name.

    The astronomer Vera Rubin at the Lowell Observatory in Flagstaff, Ariz., in 1965.Credit: via Carnegie Institution of 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.

    Vera Rubin, a young astronomer at the Carnegie Institution in Washington, was on the run in the 1970s when she overturned the universe.

    Seeking refuge from the controversies and ego-bashing of cosmology, she decided to immerse herself in the pearly swirlings of spiral galaxies, only to find that there was more to them than she and almost everybody else had thought.

    For millenniums, humans had presumed that when we gaze out at the universe, what we see is a fair representation of reality. Dr. Rubin, with her colleague Kent Ford, discovered that was not true. The universe — all those galaxies and the vast spaces between — was awash with dark matter, an invisible something with sufficient gravity to mold the large scale structures of the universe.

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

    Coma cluster via NASA/ESA Hubble, the original example of Dark Matter discovered during observations by Fritz Zwicky and confirmed by Vera Rubin

    Esteemed astronomers dismissed her findings at first. But half a century later, the still futile quest to identify this “dark matter” is a burning question for both particle physics and astronomy. It’s a pursuit that stretches from underground particle colliders to orbiting telescopes, with all manner of ground-based observatories in between.

    Last week the National Science Foundation announced that the newest observatory joining this cause will be named the Vera C. Rubin Observatory. The name replaces the mouthful by which the project was previously known: the Large Synoptic Survey Telescope, or L.S.S.T.

    The Vera C. Rubin Observatory, formerly the Large Synoptic Survey Telescope, under construction in Cerro Pachon, Chile. Credit: LSST Project/NSF/AURA

    The Rubin Observatory joins a handful of smaller astronomical facilities that have been named for women. The Maria Mitchell Observatories in Nantucket, Mass., is named after the first American woman to discover a comet. The Swope telescope, at Carnegie’s Las Campanas Observatory in Chile, is named after Henrietta Swope, who worked at the Harvard College Observatory in the early 20th century. She used a relationship between the luminosities and periodicities of variable stars to measure distances to galaxies.

    And finally there is the new Annie Maunder Astrographic Telescope at the venerable Royal Greenwich Observatory, just outside London. It is named after Annie Maunder, who with her husband Walter made pioneering observations of the sun and solar cycle of sunspots in the late 1800s.

    Heros of science, all of them.

    In a field known for grandiloquent statements and frightening intellectual ambitions, Dr. Rubin was known for simple statements about how stupid we are. In an interview in 2000 posted on the American Museum of Natural History website, Dr. Rubin said:

    “In a spiral galaxy, the ratio of dark-to-light matter is about a factor of 10. That’s probably a good number for the ratio of our ignorance to knowledge. We’re out of kindergarten, but only in about third grade.”

    Once upon a time cosmologists thought there might be enough dark matter in the universe for its gravity to stop the expansion of the cosmos and pull everything back together in a Big Crunch. Then astronomers discovered an even more exotic feature of the universe, now called dark energy, which is pushing the galaxies apart and speeding up the cosmic expansion.

    Dark Energy Survey

    Dark Energy Camera [DECam], built at FNAL

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

    Timeline of the Inflationary Universe WMAP

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

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

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

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

    These discoveries have transformed cosmology still further, into a kind of Marvel Comics super-struggle between invisible, titanic forces. One, dark matter, pulls everything together toward its final doom; the other, dark energy, pushes everything apart toward the ultimate dispersal, some times termed the Big Rip. The rest of us, the terrified populace looking up at this cosmic war, are bystanders, made of atoms, which are definitely a minority population of the universe. Which force will ultimately prevail? Which side should we root for?

    Until recently the money was on dark energy and eventual dissolution of the cosmos. But lately cracks have appeared in the data, suggesting that additional forces may be at work beneath the surface of our present knowledge.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 9:35 am on December 25, 2019 Permalink | Reply
    Tags: , , NYT   

    From The New York Times: “Crisis Looms in Antibiotics as Drug Makers Go Bankrupt” 

    New York Times

    From The New York Times

    Dec. 25, 2019
    Andrew Jacobs

    At a time when germs are growing more resistant to common antibiotics, many companies that are developing new versions of the drugs are hemorrhaging money and going out of business, gravely undermining efforts to contain the spread of deadly, drug-resistant bacteria.

    Antibiotic start-ups like Achaogen and Aradigm have gone belly up in recent months, pharmaceutical behemoths like Novartis and Allergan have abandoned the sector and many of the remaining American antibiotic companies are teetering toward insolvency. One of the biggest developers of antibiotics, Melinta Therapeutics, recently warned regulators it was running out of cash.

    Experts say the grim financial outlook for the few companies still committed to antibiotic research is driving away investors and threatening to strangle the development of new lifesaving drugs at a time when they are urgently needed.

    “This is a crisis that should alarm everyone,” said Dr. Helen Boucher, an infectious disease specialist at Tufts Medical Center and a member of the Presidential Advisory Council on Combating Antibiotic-Resistant Bacteria.

    The problem is straightforward: The companies that have invested billions to develop the drugs have not found a way to make money selling them. Most antibiotics are prescribed for just days or weeks — unlike medicines for chronic conditions like diabetes or rheumatoid arthritis that have been blockbusters — and many hospitals have been unwilling to pay high prices for the new therapies. Political gridlock in Congress has thwarted legislative efforts to address the problem.

    The challenges facing antibiotic makers come at time when many of the drugs designed to vanquish infections are becoming ineffective against bacteria and fungi, as overuse of the decades-old drugs has spurred them to develop defenses against the medicines.

    Drug-resistant infections now kill 35,000 people in the United States each year and sicken 2.8 million, according a report from the Centers for Disease Control and Prevention released last month. Without new therapies, the United Nations says the global death toll could soar to 10 million by 2050.

    The newest antibiotics have proved effective at tackling some of the most stubborn and deadly germs, including anthrax, bacterial pneumonia, E. coli and multidrug-resistant skin infections.

    The experience of the biotech company Achaogen, is a case in point. It spent 15 years and a billion dollars to win Food and Drug Administration approval for Zemdri, a drug for hard-to-treat urinary tract infections. In July, the World Health Organization added Zemdri to its list of essential new medicines.

    By then, however, there was no one left at Achaogen to celebrate.

    This past spring, with its stock price hovering near zero and executives unable to raise the hundreds of millions of dollars needed to market the drug and do additional clinical studies, the company sold off lab equipment and fired its remaining scientists. In April, the company declared bankruptcy.

    Public health experts say the crisis calls for government intervention. Among the ideas that have wide backing are increased reimbursements for new antibiotics, federal funding to stockpile drugs effective against resistant germs and financial incentives that would offer much needed aid to start-ups and lure back the pharmaceutical giants. Despite bipartisan support, legislation aimed at addressing the problem has languished in Congress.

    “If this doesn’t get fixed in the next six to 12 months, the last of the Mohicans will go broke and investors won’t return to the market for another decade or two,” said Chen Yu, a health care venture capitalist who has invested in the field.

    The former offices of Achaogen in South San Francisco. The company sold off the last of its lab equipment and fired its remaining scientists this past spring. Credit Brian L. Frank for The New York Times

    First Big Pharma fled the field, and now start-ups are going belly up, threatening to stifle the development of new drugs.

    Dr. Ryan Cirz, a microbiologist and a co-founder of Achaogen, a company whose drug, Zemdri, showed promise in treating U.T.I.s.Credit Brian L. Frank for The New York Times

    The industry faces another challenge: After years of being bombarded with warnings against profligate use of antibiotics, doctors have become reluctant to prescribe the newest medications, limiting the ability of companies to recoup the investment spent to discover the compounds and win regulatory approval. And in their drive to save money, many hospital pharmacies will dispense cheaper generics even when a newer drug is far superior.

    “You’d never tell a cancer patient ‘Why don’t you try a 1950s drug first and if doesn’t work, we’ll move on to one from the 1980s,” said Kevin Outterson, the executive director of CARB-X, a government-funded nonprofit that provides grants to companies working on antimicrobial resistance. “We do this with antibiotics and it’s really having an adverse effect on patients and the marketplace.”

    Many of the new drugs are not cheap, at least when compared to older generics that can cost a few dollars a pill. A typical course of Xerava, a newly approved antibiotic that targets multi-drug resistant infections, can cost as much as $2,000.

    “Unlike expensive new cancer drugs that extend survival by three-to-six months, antibiotics like ours truly save a patient’s life,” said Larry Edwards, chief executive of the company that makes Xerva, Tetraphase Pharmaceuticals. “It’s frustrating.”

    Tetraphase, based in Watertown, Mass., has struggled to get hospitals to embrace Xerava, which took more than a decade to discover and bring to market, even though the drug can vanquish resistant germs like MRSA and CRE, a resistant bacteria that kills 13,000 people a year.

    Tetraphase’s stock price has been hovering around $2, down from nearly $40 a year ago. To trim costs, Mr. Edwards recently shuttered the company’s labs, laid off some 40 scientists and scuttled plans to move forward on three other promising antibiotics.

    For Melinta Therapeutics based in Morristown, N.J., the future is even grimmer. Last month, the company’s stock price dropped 45 percent after executives issued a warning about the company’s long-term prospects. Melinta makes four antibiotics, including Baxdela, which recently received F.D.A. approval to treat the kind of drug-resistant pneumonia that often kills hospitalized patients. Jennifer Sanfilippo, Melinta’s interim chief executive, said she was hoping a sale or merger would buy the company more time to raise awareness about the antibiotics’ value among hospital pharmacists and increase sales.

    “These drugs are my babies, and they are so urgently needed,” she said.

    Coming up with new compounds is no easy feat. Only two new classes of antibiotics have been introduced in the last 20 years — most new drugs are variations on existing ones — and the diminishing financial returns have driven most companies from the market. In the 1980s, there were 18 major pharmaceutical companies developing new antibiotics; today there are three.

    “The science is hard, really hard,” said Dr. David Shlaes, a former vice president at Wyeth Pharmaceuticals and a board member of the Global Antibiotic Research and Development Partnership, a nonprofit advocacy organization. “And reducing the number of people who work on it by abandoning antibiotic R & D is not going to get us anywhere.”

    A new antibiotic can cost $2.6 billion to develop, he said, and the biggest part of that cost are the failures along the way.

    Some of the sector’s biggest players have coalesced around a raft of interventions and incentives that would treat antibiotics as a global good. They include extending the exclusivity for new antibiotics to give companies more time to earn back their investments and creating a program to buy and store critical antibiotics much the way the federal government stockpiles emergency medication for possible pandemics or bioterror threats like anthrax and smallpox.

    The DISARM Act, a bill introduced in Congress earlier this year, would direct Medicare to reimburse hospitals for new and critically important antibiotics. The bill has bipartisan support but has yet to advance.

    One of its sponsors, Senator Bob Casey, Democrat of Pennsylvania, said some of the reluctance to push it forward stemmed from the political sensitivity over soaring prescription drug prices. “There is some institutional resistance to any legislation that provides financial incentives to drug companies,” he said.

    Washington has not entirely been sitting on its hands. Over the past decade, the Biomedical Advanced Research and Development Authority, or BARDA, a federal effort to counter chemical, nuclear and other public health threats, has invested a billion dollars in companies developing promising antimicrobial drugs and diagnostics that can help address antibiotic resistance.

    “If we don’t have drugs to combat these multi-drug resistant organisms, then we’re not doing our job to keep Americans safe,” Rick A. Bright, the director of the agency, said.

    Dr. Bright has had a firsthand experience with the problem. Two years ago, his thumb became infected after he nicked it while gardening in his backyard. The antibiotic he was prescribed had no effect, nor did six others he was given at the hospital. It turned out he had MRSA.

    The infection spread, and doctors scheduled surgery to amputate the thumb. His doctor prescribed one last antibiotic but only after complaining about its cost and warning that Dr. Bright’s insurance might not cover it. Within hours, the infection began to improve and the amputation was canceled.

    “If I had gotten the right drug on Day 1, I would have never had to go to the emergency room,” he said.

    Achaogen and its 300 employees had held out hope for government intervention, especially given that the company had received $124 million from BARDA to develop Zemdri.

    As recently as two years ago, the company had a market capitalization of more than $1 billion and Zemdri was so promising that it became the first antibiotic the F.D.A. designated as a breakthrough therapy, expediting the approval process.

    Dr. Ryan Cirz, one of Achaogen’s founders and the vice president of research, recalled the days when venture capitalists took a shine to the company and investors snapped up its stock. “It wasn’t hype,” Dr. Cirz, a microbiologist, said. “This was about saving lives.”

    In June, investors at the bankruptcy sale bought out the company’s lab equipment and the rights to Zemdri for a pittance: $16 million. (The buyer, generics drug maker Cipla USA, has continued to manufacture the drug.) Many of Achaogen’s scientists have since found research jobs in more lucrative fields like oncology.

    Dr. Cirz lost his life savings, but he said he had bigger concerns. Without effective antibiotics, many common medical procedures could one day become life-threatening.

    “This is a problem that can be solved, it’s not that complicated,” he said. “We can deal with the problem now, or we can just sit here and wait until greater numbers of people start dying. That would be a tragedy.”

    See the full article here .


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  • richardmitnick 9:05 am on December 25, 2019 Permalink | Reply
    Tags: "There’s No Winter Break From ‘Publish or Perish’", NYT   

    From The New York Times: “There’s No Winter Break From ‘Publish or Perish’” 

    New York Times

    From The New York Times

    Dec. 18, 2019
    Dalmeet Singh Chawla


    Jay Van Bavel, a social neuroscientist at New York University, is vowing not to work during the Christmas holidays.

    A few years ago, Dr. Van Bavel had agreed to conduct peer review on a couple of manuscripts before the end of the semester. But he got really busy and ended up having to do one on Christmas Day and another on New Year’s Eve, while his family was visiting.

    “I felt like I let down myself and my family,” said Dr. Van Bavel, who gets asked to conduct peer-review 100 to 200 times a year. But he says he has now learned his lesson, and is not planning to do any work in the Christmas holidays this year, except perhaps the odd email.

    If Dr. Van Bavel holds to his vow, he’ll beat the trend of many of his colleagues. While you might be setting an out-of-office message and backing away from your keyboard as the winter holidays set in, many researchers in academia can be found working straight through the season. Scientists based in the United States are, in fact, the third most likely to work during holidays, behind only their counterparts in Belgium and Japan, according to a study published Thursday in BMJ.

    The study — aiming to quantify some of the overwork and burnout experienced by researchers in the sciences — examined nearly 50,000 manuscript submissions and more than 75,000 peer-review submissions to BMJ and its sister journal, BMJ Open. More than a tenth of U.S.-based researchers who submitted manuscripts and peer review reports to journals did so during the holidays.

    At the same time, researchers in China lead the world in working on weekends, where more than a fifth of academics submitted papers and peer-review reports, followed by those based in Japan, Italy and Spain. More than a tenth of researchers in the United States turned in studies on weekends, and more than 15 percent conducted peer review.

    Scandinavian nations had the best work-life balance. Scientists in Sweden were least likely to work during holidays, and those in Norway generally kept their weekends free.

    Adrian Barnett, a statistician and metascience researcher at Queensland University of Technology in Australia, who co-wrote the analysis, thought of conducting the analysis while submitting a paper on the weekend.

    “This is a real marker of how hard I’m working,” he said.

    The study has shortcomings. Among them, it only accounts for manuscript submissions and peer review, just two of many tasks on an academic’s plate, for instance.

    “While this study provides a starting point to demonstrate that academics are indeed spending time working on weekends and holidays, it does not delve deeper into the types or amounts of work that academics may be doing on weekends or holidays,” says Valerie Miller, assistant director of postdoctoral affairs at the University of Chicago.

    Dr. Barnett acknowledges these shortcomings, although he noted that these markers were most easily traceable because academic publishers time-stamp electronic study and peer-review submissions.

    Dr. Miller is currently conducting a survey [U Chicago] on the work of postdoctoral researchers, who are usually considered to be early in their careers. A study conducted by the Young Academy of Europe [Nature] earlier this year found that around half of early-career researchers there work more than 50 hours a week. Other studies [Nature] have also reported a mental health crisis among graduate students, with large numbers saying their Ph.D. is the cause of their mental condition.

    Another limitation of the BMJ study is that it can’t distinguish between researchers’ career stages, and only includes scientists working predominantly in health and medicine.

    While submitting a study can lead to a publication that is valuable for an academic’s career, peer-review can be a more thankless task.

    Some countries, like Italy, Spain, France and New Zealand report higher percentages of peer-review activity on weekends than manuscript submissions. Dr. Barnett suggests that academics find themselves lacking the time to perform this labor during their workweek because it’s often not considered “actual work.”

    As a measure of how peer review is regarded, a survey published earlier [Physics Today] this year found that around half of just under 500 researchers had during their careers ghostwritten peer review reports on behalf of senior faculty.

    “Peer review is central to the scientific mission and ought to be re-centered in our evaluation systems, not something to be done in an academic’s ‘free time,’” said Rebeccah Lijek, a biologist at Mount Holyoke College in Massachusetts who led the ghostwriting study.

    It’s also getting more difficult to recruit academics to conduct peer review, a report released last year [Undark] showed, and a small batch of reviewers seem to be doing a disproportionate amount of peer review.

    Dr. Lijek thinks Dr. Barnett’s findings are only the tip of the iceberg: “What’s still under water are the many hours of labor performed by teams of junior researchers that precede submission.”

    Dr. Barnett feels that academics are forced to do too much.

    “We’re pushed to produce more so that universities can rise up the league tables,” he said.

    With that in mind, Dr. Van Bavel is trying to take a new approach in his lab.

    “A few weeks ago, I had a lab meeting where we created a work life balance policy to minimize the pressure to work on the weekend,” he said.

    See the full article here .


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  • richardmitnick 8:24 am on December 24, 2019 Permalink | Reply
    Tags: , , , NYT,   

    From The New York Times: “A 3D Encounter With a Violent Volcano’s Underbelly” 

    New York Times

    From The New York Times

    Dec. 18, 2019
    Robin George Andrews

    Lava flows on Réunion Island from Piton de la Fournaise, one of the world’s most active volcanoes, during a 2015 eruption.Credit RICHARD BOUHET/AFP via Getty Images

    Réunion, a French island in the western Indian Ocean, is a jigsaw of two massive shield volcanoes. The younger, Piton de la Fournaise or “peak of the furnace,” is a furious factory of lava, erupting every eight months on average over the last four decades.

    The Piton de la Fournaise volcano on Réunion Island. http://www.brianiannone.com/

    That hellish environment makes it an ideal real-world laboratory for studying the internal viscera of volcanoes, about which scientists know surprisingly little. The more they map out, the better they grow to understand why, how and when volcanoes all over the world will next erupt.

    In a study published this month in Scientific Reports, volcanologists reported using a novel technique to map out 58 square miles of Piton de la Fournaise’s shadowy underworld. Their survey revealed a 3D view of its insides, from the plumbing network of superheated hydrothermal fluids to scores of faults that allow magma to sneak up to the surface during eruptions.

    The success of this technique on Réunion means that it could be deployed elsewhere, said Marc Dumont, a geophysicist at the Sorbonne University in Paris and the lead author of the study, from lava effusing mountains like Hawaii’s Kilauea to the more explosive peaks in the volcanic spine running up America’s Pacific Northwest.

    Lava erupts from a fissure in the Leilani Estates neighbourhood near Pahoa on the island of Hawaii, on May 24. (Grace Simoneau/FEMA via Associated Press)

    Piton de la Fournaise is a byzantine volcano, comprehensively monitored by scientists as it is regularly modified by eruptions. Spidery tendrils of magma escape through lines of weakness. When molten material meets the groundwater cycling through the volcano’s uppermost segments, powerful explosions can happen without warning, much like the lethal detonations that recently rocked New Zealand’s White Island. Old faults can suddenly slip and cause parts of the volcano to catastrophically collapse.

    These features control how future eruptions manifest, so finding out where they are is of paramount importance.

    An example of the 3D models produced by the research.Credit via Marc Dumont

    One way to locate these subterranean features is to use instruments to see how well the rocks below conduct electricity. Scorching, circulating water is highly conductive. Old volcanic rock that has been degraded by it has water inside its Swiss cheese-like holes, making it relatively conductive. Newly cooled, structurally sound lava flows are much more electrically resistant.

    Deploying electrical resistivity-detecting instruments on an active volcano can be both dangerous and time consuming. Often, expeditions must choose between a high-resolution underground map of a small area or a low-resolution map of a larger space.

    Scientists had previously traipsed across the Piton de la Fournaise by foot, deploying equipment to reveal parts of its internal structure. To speed things up, they took to a helicopter.

    Hewing disquietingly close to the volcano over four days in 2014, the helicopter’s winch held a sizable hoop that could electrically excite the rocks below. In response, electromagnetic threads snaked back up from the volcano, which were detected by the helicopter. These invisible strings differed, depending on the properties of the rocks, which allowed scientists to identify individual ingredients and layers of Réunion’s youthful volcanic cake down to a depth of 3,300 feet.

    Scientists were previously aware of the existence of some of the volcano’s rift zones, faults and fluid networks. But they now have a 3D schematic providing an unparalleled peek into the volcano’s active subsurface, showing with precision where its magmatic appendages and pathways, rocky scars and hydrothermal pipes are in relation to each other.

    “Our continuing ability to image the internal structure of volcanoes in 3D is revolutionizing how we understand volcanism,” said Sam Mitchell, a submarine volcanologist not involved with the work, and who recently joined an aquatic voyage to peer into the heart of a massive underwater volcano near Oregon. No matter which volcano is being mapped, he said, the goal of these projects is the same: to identify hazards and save lives.

    See the full article here .


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  • richardmitnick 7:59 am on December 23, 2019 Permalink | Reply
    Tags: "Will the United States Lose the Universe?", , , , , , , , Mount Wilson Observatory-60-inch Hale telescope and 100-inch Hooker telescope built in 1917 where Edwin Hubble discover that the universe is expanding, NYT, ,   

    From The New York Times: “Will the United States Lose the Universe?” 

    New York Times

    From The New York Times

    Dec. 23, 2019
    Dennis Overbye

    A Supermoon, or perigee moon, rises behind the historic Mount Wilson Observatory, northeast of Los Angeles on July 12, 2014. The observatory houses the 60-inch Hale telescope, built in 1908, and the, formerly world’s largest, 100-inch Hooker telescope built in 1917.Credit: David McNew/Getty Images

    For more than a century, American astronomers have held bragging rights as observers of the cosmos. But that dominance may soon slip away.

    The United States is about to lose the universe.

    It wouldn’t be quite the same as, say, losing China to communism in the 1940s. No hostile ideologies or forces are involved. But much is at stake: American intellectual, technical and economic might, cultural pedigree and the cosmic bragging rights that have been our nation’s for the last century.

    In 1917, the 100-inch Hooker telescope went into operation on Mount Wilson in California, and Edwin Hubble eventually used it to discover that the universe is expanding.

    Mt Wilson 100 inch Hooker Telescope Interior

    Edwin Hubble looking through a 100-inch Hooker telescope at Mount Wilson in Southern California, 1929 discovers the Universe is Expanding

    Until very recently, the mightiest telescopes on Earth have been on American mountaintops like Palomar, Kitt Peak and Mauna Kea. They revealed the Big Bang, black holes and quasars.

    Caltech Palomar 200 inch Hale Telescope, Altitude 1,713 m (5,620 ft), located in San Diego County, California, United States

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

    Some of the observatories on Mauna Kea [Credit: Institute for Astronomy, University of Hawaii]

    But no more. In 2025 the European Southern Observatory, a multinational treaty organization akin to CERN but looking outward instead of inward, will invite the first light into a telescope that will dwarf all others. The European Extremely Large Telescope on Cerro Paranal in Chile will have a primary light-gathering mirror 39 meters in diameter, making it 13 times more powerful than any telescope now working and more sharp-eyed than the iconic Hubble Space Telescope.

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    The European goliath will be able to see the glow of planets orbiting other stars and peer into the black hearts of faraway galaxies. Who knows what else it might bring into view.

    There are two American-led telescope projects that could compete with the European giant, if they are ever built: the Thirty Meter Telescope, slated for construction on Mauna Kea, in Hawaii, and the Giant Magellan on Cerro Las Campanas, in Chile. But both are mired in financial difficulties and political controversies, and their completion, if it happens, is at least a decade away.

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level

    Giant Magellan Telescope, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    Carnegie Las Campanas Observatory in the southern Atacama Desert of Chile in the Atacama Region approximately 100 kilometres (62 mi) northeast of the city of La Serena,near the southern end and over 2,500 m (8,200 ft) high

    Work on the Thirty Meter Telescope, or T.M.T., has been stalled for years by a protest movement arguing that decades of telescope building on Mauna Kea have polluted and desecrated a mountain that is sacred to Polynesian culture, and have violated the rights of native Hawaiians. The team behind the project has vowed to move it to the Canary Islands if it can’t go forward in Hawaii.

    Both projects are hundreds of millions of dollars short of the financing they need to build their telescopes. Without them, American astronomers, accustomed to V.I.P. seating in observations of the universe, could be largely consigned to the cosmic bleachers in years to come. Early next year, probably in late February, representatives of the two telescope projects will appear before a blue-ribbon panel of the National Academy of Sciences plead for help.

    The panel is part of the so-called Decadal Survey, in which the astronomy community ranks its priorities for spending federal money. Congress and agencies like the National Science Foundation traditionally take their cues from the survey’s recommendations. A high ranking could shake loose money from the National Science Foundation, which has traditionally funded ground-based observatories.

    Without the National Academy’s endorsement, the telescopes face an uphill struggle to reach completion. Even with an endorsement, the way will be tough. The Trump Administration appears to be trying to eliminate the National Science Foundation’s funding for large facilities such as observatories. So much for successes like the Laser Interferometer Gravitational-Wave Observatory, which detected colliding black holes. Luckily for now, Congress has resisted these cuts.

    The telescopes are not cheap. They will need at least a billion more dollars between them to get to the finish line, maybe more. So far, the team behind the Giant Magellan Telescope has raised about $600 million from its partners and seeks an equivalent amount from the National Science Foundation.

    Telescopes at the summit of Mauna Kea in Hawaii. Gov. Ige says he and other state employees have received death threats amid the heated debate over building a giant telescope on the state’s highest peak.Credit…Caleb Jones/Associated Press

    Visible here are Keck telescopes, NAOJ Subaru and NASA Infrared Telescope facility:

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

    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level

    The T.M.T. collaboration, now officially know as the T.M.T. International Observatory — T.I.O., in case you haven’t read enough acronyms — has publicly put the cost of its telescope at $1.4 billion, but recent analyses by knowledgeable outsiders come up with a price tag of more than $2 billion.

    In return for that investment, all American astronomers, not just collaboration members, will gain access to both giant telescopes to pursue certain important projects.

    Granted, even without these mammoth glass eyes, American astronomers will still have instruments in space, like the beloved Hubble Space Telescope and its successor, the James Webb Space Telescope. But Hubble is growing old, and the Webb telescope, with a snake-bitten history of development, will spend a tense several months unfolding itself in space once it reaches orbit in 2021.

    Astronomers will also have the Large Synoptic Survey Telescope, already under construction in Chile, which will in effect make movies of the entire universe every few nights.

    The LSST Vera Rubin Survey Telescope

    LSST Camera, built at SLAC

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

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

    But that telescope is only 8 meters in size and will not see as deep into space as the Really Big Eyes. And, of course, U.S. astronomers will be able to sign on to projects as partners of their European colleagues, much like American physicists now troop to CERN, in Geneva.

    The need for giant, ground-based telescopes was apparent to American astronomers 20 years ago. The Thirty Meter project originated at the California Institute of Technology and the University of California, and has grown to include Canada, Japan, China and India. The Giant Magellan started at the Carnegie Observatories and now includes several universities and research institutes, as well as South Korea, Australia and the State of São Paulo, in Brazil.

    The two projects have been fighting for partners and funds ever since. Two telescopes, one in the North and the other in the South, would complement each other, so the story has gone. Until now, neither telescope has been able to enlist the federal government as a partner.

    Last year the two groups agreed to make joint cause to Academy panel and the astronomical community.

    As Matt Mountain, president of the Association of Universities for Research in Astronomy said then, “Both projects finally woke up to the fact they are being creamed by the European 39-meter.”

    But the Thirty Meter team has yet to make peace with the protesters, in Hawaii, for whom the telescope represents a long history of colonial disrespect of native rights and culture.

    Last July, construction workers arrived at Mauna Kea to start building the telescope, only to find that nine protesters had handcuffed themselves to a cattle guard, blocking the road up the mountain.

    The ensuing standoff captured the imagination of people sympathetic to the plight of indigenous people, including Dwayne “The Rock” Johnson and Representative Tulsi Gabbard, Democrat of Hawaii (who is also running for president), and generated unease within the collaboration. In July, Vivek Goel, vice president for research at the University of Toronto, one of the Canadian partners in the Thirty Meter projected, issued a statement that the university “does not condone the use of police force in furthering its research objectives.”

    The Thirty Meter team recently secured a building permit for their alternative telescope site, on La Palma, in Spain’s Canary Islands. But that mountain is only half as high as Mauna Kea, leaving more atmosphere and water vapor between the astronomers and the stars. Some of the T.M.T. partners, like Canada and Japan, are less than enthusiastic about the possible switch. An environmental organization, Ben Magec, has vowed to fight the telescope, saying the area is rife with archaeological artifacts. Moreover, moving the telescope off American soil, would only complicate the politics of obtaining funding from the National Science Foundation.

    Back in 2003, when these giant-telescope efforts were starting, Richard Ellis, an astronomer now at University College London, said, “We are really going to have a hard time building even one of these.” He didn’t know just how true that was.

    Now, as the wheels of the academic and government bureaucracy begin to turn, many American astronomers worry that they are following in the footsteps of their physicist colleagues. In 1993, Congress canceled the Superconducting Super Collider, and the United States ceded the exploration of inner space to Europe and CERN, which built the Large Hadron Collider, 27 miles in diameter, where the long-sought Higgs boson was eventually discovered.

    Superconducting Super Collider map, in the vicinity of Waxahachie, Texas, Cancelled by The U.S. Congress in 1993 because it showed no “immediate economic benefit”

    CERN/LHC Map

    The United States no longer builds particle accelerators. There could come a day, soon, when Americans no longer build giant telescopes. That would be a crushing disappointment to a handful of curious humans stuck on Earth, thirsting for cosmic grandeur. In outer space, nobody can hear you cry.

    See the full article here .


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  • richardmitnick 1:29 pm on December 9, 2019 Permalink | Reply
    Tags: "How an Icy Moon of Saturn Got Its Stripes", , , , , , NYT   

    From The New York Times: “How an Icy Moon of Saturn Got Its Stripes” 

    New York Times

    From The New York Times

    Dec. 9, 2019
    Nadia Drake

    Scientists have developed an explanation for one of the most striking features of Enceladus, an ocean world that has the right ingredients for life.

    A false-color mosaic of Saturn’s moon Enceladus, taken during a 2008 fly-by by NASA’s Cassini spacecraft, from a distance of about 15.6 miles of the moon’s surface.Credit: JPL/NASA

    NASA/ESA/ASI Cassini-Huygens Spacecraft

    Of the strange and unexplained terrains in our solar system, the south pole of Saturn’s moon Enceladus is among the most perplexing.

    Enceladus is an ocean world, with a vast and briny sea tucked beneath its icy crust; this makes it one of the most tantalizing places in the solar system to look for life beyond Earth. But unlike other frozen moons, Enceladus constantly erupts. The tiny world blasts salty water into space through cracks in its crystalline shell. These fissures, raked across the moon’s southern pole, are roughly parallel and evenly spaced. And ever since scientists first took a good look at this alien moon, they’ve had a tough time explaining those “tiger stripes.”

    “What is going on?” said Doug Hemingway of the Carnegie Institution for Science. “In a way, it’s an obvious question — it’s been in the back of everyone’s mind for a long time.”

    Now, Dr. Hemingway and his colleagues think they know how the moon got its stripes — and, curiously, why the stripes are found only at the Enceladian south pole. They described their hypothesis Monday in Nature Astronomy. Learning more about how extraterrestrial oceans on worlds such as Enceladus evolve and interact with planetary surfaces is important for understanding how life might exist beyond Earth and how we might find it, Dr. Hemingway said.

    In 2005, NASA’s Cassini spacecraft first swooped in and stared at 313-mile-wide Enceladus. The spacecraft saw a stunning array of geysers erupting from the moon’s south pole — eruptions that vent the moon’s ocean into space and sculpt Saturn’s E ring. Later, when Cassini flew through the jets, it tasted an alien soup containing all the ingredients necessary for life as we know it.

    Enceladus’s so-called “tiger stripes” near its southern pole.Credit…JPL/NASA

    The moon’s southern hemisphere is riven by four prominent fractures. Approximately parallel and spaced about 20 miles apart, the massive cracks are, like other features of Enceladus, named after locations in “One Thousand and One Nights.”

    Previous ideas about the origins of the cracks — Alexandria, Baghdad, Cairo, Damascus and a smaller crack unpoetically referred to as “E” — included massive impacts, hot spots, strike-slip faulting and a migrating icy shell. Dr. Hemingway and his colleagues modeled the evolution of the moon’s icy shell, accounting for its thickness, elasticity, strength and temperature, and uncovered a simpler, more comprehensive explanation.

    Some time after it formed, they think, Enceladus slowly began to cool. Some of its inner ocean froze, expanded — as frozen water does — and strained the moon’s icy crust, which was thinner at the poles.

    Eventually, the swelling sea fractured the southern crust.

    The first fissure to form was 80-mile-long Baghdad, the largest and most prominent of the tiger stripes. As water began erupting through Baghdad, some of it snowed back to the moon’s surface, piling up near the fracture’s margins. The weight of that accumulating material strained the ice shell, and new cracks — Cairo and Damascus — opened up on either side of Baghdad, each roughly parallel and about 20 miles away.

    Then Alexandria and “E” opened up.

    “Why doesn’t this cascading sequence just keep going?” Dr. Hemingway said. “It’s not clear. Maybe as you open up more and more of these fractures, the eruption rate per ridge kind of drops, or the overall background ice shell thickness just gets too big.”

    The process may have taken between 100,000 and one million years. The tiger stripes’ even spacing is simply a result of the ice’s elasticity and its thickness, which is thinner at the poles and bulkier at the equator.

    But why did the stripes only rupture the southern pole?

    “It’s kind of a coin toss whether that first fracture happens at the north pole or the south pole,” Dr. Hemingway said. But as soon as the crust breaks open, he added, the swelling ocean’s pressure is relieved “and the other pole will just stay quiet for the rest of time.”

    Although this new model answers many questions about the strange moon orbiting Saturn, several remain. Alyssa Rhoden of the Southwest Research Institute called the hypothesis plausible, but she wonders how the model links up with other, less dramatic fractures and features on the moon:

    “Now that we have this idea, how do we fit it into the broader picture of how Enceladus evolved over time?”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 8:32 am on December 9, 2019 Permalink | Reply
    Tags: "How Life on Our Planet Made It Through Snowball Earth", , NYT,   

    From The New York Times: “How Life on Our Planet Made It Through Snowball Earth” 

    New York Times

    From The New York Times

    Dec. 2, 2019
    Lucas Joel

    An artist’s concept of the Earth frozen in snow, during one of the planet’s most severe ice ages.Credit: Chris Butler/Science Source

    Rusty rocks left over from some of our planet’s most extreme ice ages hint at oases for survival beneath the freeze.

    Today, the world is warming. But from about 720 to 635 million years ago, temperatures swerved the other way as the planet became encased in ice during the two ice ages known as Snowball Earth.

    It happened fast, and within just a few thousand years or so, ice stretched over both land and sea, from the poles to the tropics. Life lived in the oceans at the time, and the encroaching ice entombed that life, cutting it off from both the sun and the atmosphere.

    “This is the one time when Earth’s natural thermostat broke,” said Noah Planavsky, a biogeochemist at Yale University. “The question on everyone’s minds was: How did life actually make it through this?”

    Glaciations can drive mass extinctions of life. Yet life, including perhaps our distant animal ancestors, somehow survived these deep freezes. In research published Monday in Proceedings of the National Academy of Sciences, Dr. Planavsky and his colleagues report the discovery of oases just beneath the ancient ice sheets that likely helped life persevere.

    Snowball Earth came to an abrupt end over a half-billion years ago, but its marks still exist in remote corners of the planet. In 2015, to reach one of those corners, Max Lechte and his graduate adviser at the time, Malcolm Wallace, both sedimentologists at the University of Melbourne, drove 15 hours into the South Australian outback.

    They trekked over hills made of red-colored rock, and it was so hot out — about 122 degrees Fahrenheit — that the soles of Dr. Wallace’s boots melted.

    “A bit of duct tape fixed that up,” said Dr. Lechte, who led the new research.

    These red-hot rocks formed in the oceans during the snowball glaciations, and their color caught Dr. Lechte’s eye, so he took a few samples. Then, in 2015 and 2016, he traveled to Namibia and Death Valley in California and found more rocks — also red — that formed at the same time.

    The iron-rich rocks of Death Valley in California provide a window into Earth’s most severe ice age.Credit: Maxwell A. Lechte

    The rocks’ color signaled to Dr. Lechte that they are rich in iron, which means they turned red for the same reason that old cars with iron exteriors turn red: They rusted.

    Oxygen needs to be present for iron to rust. It also needs to be present for animals and many other organisms to survive. If the iron rocks below the ancient oceans rusted, then there was also oxygen in those oceans. And if there was oxygen, then oxygen-breathing life-forms had a lifeline they could cling to.

    “This is the first direct evidence for oxygen-rich marine environments during Snowball Earth,” said Dr. Lechte, now a postdoctoral researcher at McGill University in Canada.

    But how that oxygen got into the oceans in the first place was a mystery. The atmosphere is a major source of oxygen for the oceans, and with the ice sheets of Snowball Earth acting as giant air-blocking shields, oxygen in seawater should’ve been nonexistent.

    “This could’ve led to anoxic oceans, which could’ve killed off life-forms that need oxygen to survive.” Dr. Lechte said. “It presents a bit of an unsolved problem.”

    In labs at Yale as well as Nanjing University in China, Dr. Lechte and his team crushed the iron-rich rocks, dissolved them in acid and measured the abundances of different iron isotopes. They found that the iron in rocks that formed far out in the open oceans rusted much less than the iron in rocks that formed closer to land, right where ice sheets dove from continents and into the oceans.

    Today, beneath ice sheets in Antarctica, glacial meltwater streams flow into the Southern Ocean. That water melts from ice that can have air bubbles trapped inside it, and those bubbles can seed the meltwater streams with oxygen. On Snowball Earth, Dr. Planavsky explained, such oxygen-laden streams flowed into the oceans around the edges of continents and sustained life.

    Paul Hoffman, a geologist at Harvard University who pioneered the Snowball Earth hypothesis [Science], thinks this idea for how oxygen made it into the oceans is solid. “I’m attracted to the idea, and I think it’s consistent with my own observations,” he said.

    But, Dr. Hoffman added, whether or not this oxygen pump was the main thing that helped many living things survive those ice ages is still an open question.

    “We just don’t know enough from a theoretical standpoint about how life would have responded to the challenge of a Snowball Earth,” he said.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

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