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  • richardmitnick 1:35 pm on September 22, 2017 Permalink | Reply
    Tags: Dauphas and his team looked at titanium in the shales over time, , Geologists often look at a particular kind of rock called shales, , If you fertilize the ocean with phosphorus life will bloom, Plate techtonics is believed to be needed to create felsic rock, Study suggests significant tectonic action was already taking place 3.5 billion years ago—about half a billion years earlier than currently thought, The flood of oxygen came from a surge of photosynthetic microorganisms - cyanobacteria, The titanium timeline suggests that the primary trigger of the surge of phosphorus was the change in the makeup of mafic rock over time, Tracing the path of metallic element titanium through the Earth’s crust across time, U Chicago   

    From U Chicago: “Study suggests tectonic plates began moving half a billion years earlier than thought” 

    U Chicago bloc

    University of Chicago

    September 21, 2017
    Louise Lerner

    1
    While previous studies had argued that Earth’s crust 3.5 billion years ago looked like these Hawaiian lavas, a new study led by UChicago scientists suggests by then much of it had already been transformed into lighter-colored felsic rock by plate tectonics.
    Photo by Basil Greber

    The Earth’s history is written in its elements, but as the tectonic plates slip and slide over and under each other over time, they muddy that evidence—and with it the secrets of why Earth can sustain life.

    A new study led by UChicago geochemists rearranges the picture of the early Earth by tracing the path of metallic element titanium through the Earth’s crust across time. The research, published Sept. 22 in Science, suggests significant tectonic action was already taking place 3.5 billion years ago—about half a billion years earlier than currently thought.

    The crust was once made of uniformly dark, magnesium- and iron-rich mafic minerals. But today the crust looks very different between land and ocean: The crust on land is now a lighter-colored felsic, rich in silicon and aluminum. The point at which these two diverged is important, since the composition of minerals affects the flow of nutrients available to the fledgling life struggling to survive on Earth.

    “This question has been discussed since geologists first started thinking about rocks,” said lead author Nicolas Dauphas, the Louis Block Professor and head of the Origins Laboratory in the Department of the Geophysical Sciences and the Enrico Fermi Institute. “This result is a surprise and certainly an upheaval in that discussion.”

    To reconstruct the crust changing over time, geologists often look at a particular kind of rock called shales, made up of tiny bits of other rocks and minerals that are carried by water into mud deposits and compressed into rock. The only problem is that scientists have to adjust the numbers to account for different rates of weathering and transport. “There are many things that can foul you up,” Dauphas said.

    To avoid this issue, Dauphas and his team looked at titanium in the shales over time. This element doesn’t dissolve in water and isn’t taken up by plants in nutrient cycles, so they thought the data would have fewer biases with which to contend.

    They crushed samples of shale rocks of different ages from around the world and checked in what form its titanium appeared. The proportions of titanium isotopes present should shift as the rock changes from mafic to felsic. Instead, they saw little change over three and a half billion years, suggesting that the transition must have occurred before then.

    2
    These granite peaks are an example of felsic rock, created via plate tectonics. Photo by Basil Greber

    This also would mark the beginning of plate tectonics, since that process is believed to be needed to create felsic rock.

    “With a null response like that, seeing no change, it’s difficult to imagine an alternate explanation,” said Matouš Ptáček, a UChicago graduate student who co-authored the study.

    “Our results can also be used to track the average composition of the continental crust through time, allowing us to investigate the supply of nutrients to the oceans going back 3.5 billion years ago,” said Nicolas Greber, the first author of the paper, then a postdoctoral researcher at UChicago and now with the University of Geneva.

    Phosphorous leads to life

    The question about nutrients is important for our understanding of the circumstances around a mysterious but crucial turning point called the great oxygenation event. This is when oxygen started to emerge as an important constituent of Earth’s atmosphere, wreaking a massive change on the planet—and making it possible for multi-celled beings to evolve.

    The flood of oxygen came from a surge of photosynthetic microorganisms; and in turn their work was fostered by a surge of nutrients to the oceans, particularly phosphorus. “Phosphorus is the most important limiting nutrient in the modern ocean. If you fertilize the ocean with phosphorus, life will bloom,” Dauphas said.

    The titanium timeline suggests that the primary trigger of the surge of phosphorus was the change in the makeup of mafic rock over time. As the Earth cooled, the mafic rock coming out of volcanoes and underground melts became richer in phosphorus.

    “We’ve known for a long time that mafic rock changed over time, but what we didn’t know was that their contribution to the crust has stayed rather consistent,” Ptáček said.

    Other institutions on the study were the University of California-Riverside, University of Oregon-Eugene and the University of Johannesburg.

    See the full article here .

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    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

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  • richardmitnick 2:35 pm on August 30, 2017 Permalink | Reply
    Tags: , , , , Supernova 2012ca, Type Ia supernovas, U Chicago, UChicago scientists detect first X-rays from mystery supernovas   

    From U Chicago: “UChicago scientists detect first X-rays from mystery supernovas” 

    U Chicago bloc

    University of Chicago

    August 23, 2017
    Louise Lerner

    1
    Scientists have detected the first X-rays from what appears to be a type Ia supernova, located inside the spiral-shaped galaxy ESO 336-G009, about 260 million light-years from Earth. DSS.

    Exploding stars lit the way for our understanding of the universe, but researchers are still in the dark about many of their features.

    A team of scientists, including scholars from the University of Chicago, appear to have found the first X-rays coming from type Ia supernovas. Their findings are published online Aug. 23 in the Monthly Notices of the Royal Astronomical Society.

    Astronomers are fond of type Ia supernovas, created when a white dwarf star in a two-star system undergoes a thermonuclear explosion, because they burn at a specific brightness. This allows scientists to calculate how far away they are from Earth, and thus to map distances in the universe. But a few years ago, scientists began to find type Ia supernovas with a strange optical signature that suggested they carried a very dense cloak of circumstellar material surrounding them.

    2
    An image showing X-rays detected from the supernova 2012ca (inside the circle). Image has been smoothed and colorized.
    Photo by Vikram Dwarkadas/Chandra X-ray Observatory

    NASA/Chandra Telescope

    Such dense material is normally only seen from a different type of supernova called type II, and is created when massive stars start to lose mass. The ejected mass collects around the star; then, when the star collapses, the explosion sends a shockwave hurtling at supersonic speeds into this dense material, producing a shower of X-rays. Thus we regularly see X-rays from type II supernovas, but they have never been seen from type Ia supernovas.

    When the UChicago-led team studied the supernova 2012ca, recorded by the Chandra X-ray Observatory, however, they detected X-ray photons coming from the scene.

    “Although other type Ia’s with circumstellar material were thought to have similarly high densities based on their optical spectra, we have never before detected them with X-rays,” said study co-author Vikram Dwarkadas, research associate professor in the Department of Astronomy and Astrophysics.

    The amounts of X-rays they found were small—they counted 33 photons in the first observation a year and a half after the supernova exploded, and ten in another about 200 days later—but present.

    “This certainly appears to be a Ia supernova with substantial circumstellar material, and it looks as though it’s very dense,” he said. “What we saw suggests a density about a million times higher what we thought was the maximum around Ia’s.”

    It’s thought that white dwarfs don’t lose mass before they explode. The usual explanation for the circumstellar material is that it would have come from a companion star in the system, but the amount of mass suggested by this measurement was very large, Dwarkadas said—far larger than one could expect from most companion stars. “Even the most massive stars do not have such high mass-loss rates on a regular basis,” he said. “This once again raises the question of how exactly these strange supernovas form.”

    “If it’s truly a Ia, that’s a very interesting development because we have no idea why it would have so much circumstellar material around it,” he said.

    “It is surprising what you can learn from so few photons,” said lead author and Caltech graduate student Chris Bochenek; his work on the study formed his undergraduate thesis at UChicago. “With only tens of them, we were able to infer that the dense gas around the supernova is likely clumpy or in a disk.”

    More studies to look for X-rays, and even radio waves coming off these anomalies, could open a new window to understanding such supernovas and how they form, the authors said.

    See the full article here .

    Please help promote STEM in your local schools.

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 10:15 am on August 12, 2017 Permalink | Reply
    Tags: , , , New program teaches data science for energy and environment research, U Chicago   

    From U Chicago: “New program teaches data science for energy and environment research” 

    U Chicago bloc

    University of Chicago

    August 11, 2017
    Rob Mitchum

    Innovative curriculum will arm graduate students with critical tools for modern science.

    1
    An interdisciplinary program will train graduate students in data science to tackle issues related to food, energy and water.

    For the future of the planet, there are few research subjects more important than the global supplies of food, water and energy. To comprehensively study, understand and inform policy around these complex systems, the next generation of researchers in the physical, social and biological sciences will need fluency with data analysis methods that transverse traditional academic boundaries.

    A new interdisciplinary curriculum will train graduate students from geosciences, economics, computer science, public policy and other programs in computational and data science techniques critical for modern science. With a $3 million award from the National Science Foundation, the new research traineeship grant will combine expertise from across UChicago and Argonne National Laboratory in computing, statistics, social science, climate and agriculture.

    “This program will equip graduate students with the tools needed to advance the study of issues related to food, energy and water,” said Elisabeth Moyer, associate professor of atmospheric science in the Department of the Geophysical Sciences. “Our vision is to produce students who have the computational skills and breadth of knowledge, from social to physical sciences, needed to tackle these critical research subjects in all their complexity.”

    As Earth’s population rises in the coming years, demand for food, energy and water is expected to soar. The global scale and interdependence of these sectors—where increased agriculture decreases freshwater supplies, while both are affected by the environmental impact of accelerating energy production—necessitates research collaboration across fields. Improved data collection and modeling on these topics creates promising opportunities for understanding their complexities, but only if analyzed with the right computational methods.

    The program will produce students with a foundation in a discipline such as geosciences, economics or public policy, as well as the computational skills and breadth of multidisciplinary knowledge to tackle complex questions in food, energy and water. A three-year curriculum including boot camps, retreats, new courses and practicum projects will give each student experience working with data science methods and scientists from fields other than their own.

    Additional training in scientific communication and professional development, as well as opportunities for international research experience with the Potsdam Institute for Climate Impact Research and the African Institute for Mathematical Sciences, will further prepare students for research careers in this area.

    “We want to extend education outside the boundaries of traditional silo-ed disciplinary programs,” said Ryan Kellogg, professor at the Harris School of Public Policy. “This program will provide students with the computational skills needed to exploit the growing torrent of relevant data, and give them experience both interacting across disciplines and translating results to non-academic audiences.”

    Campus as a laboratory

    As part of the curriculum, students will receive introductions to computing in the social sciences and geosciences, spatial statistics and imagery analysis, geographic information systems (GIS), data science fundamentals, time series analysis and environmental economics. A general course on the food/energy/water system, drawn from existing courses for interdisciplinary audiences taught by Moyer and Cristina Negri, environmental engineer at Argonne and fellow of the Institute for Molecular Engineering, will be followed by a data analysis practicum where groups of students work with real data and organizations in government and industry.

    The program will build upon successful UChicago training initiatives such as the Executive Program in Applied Data Analytics, the Computational Analysis and Public Policy curriculum at the Harris School of Public Policy and the Data Science for Social Good Summer Fellowship.

    nstruction and mentorship will be provided by several UChicago research groups, including the Center for Robust Decision-Making on Climate and Energy Policy (climate and agricultural modeling), Knowledge Lab (text mining), the Energy Policy Institute at UChicago (environmental and energy economics), the Center for Data Science and Public Policy (data analytics and project management) and the Center for Spatial Data Science (spatial analysis). High-performance computing resources and tutorials will be provided by the Research Computing Center.

    “All across the University of Chicago campus, we have researchers applying innovative data science techniques to important questions in energy and the environment,” said Michael Franklin, the Liew Family Chair of Computer Science. “With this new program, we can extend that strength to enrich our graduate education, making our campus a laboratory for training a new generation of interdisciplinary, computational-minded scientists.”

    The award is one of 17 given out by the National Science Foundation this month as part of their NSF Research Traineeship program. The foundation awarded a total of $51 million to “develop and implement bold, new, potentially transformative models for graduate education in science, technology, engineering and mathematics fields.”

    “Integration of research and education through interdisciplinary training will prepare a workforce that undertakes scientific challenges in innovative ways,” said Dean Evasius, director of the NSF Division of Graduate Education in a news release. “The NSF Research Traineeship awards will ensure that today’s graduate students are prepared to pursue cutting-edge research and solve the complex problems of tomorrow.”

    In addition to Moyer, Kellogg and Franklin, additional investigators on the award include Joshua Elliott, Computation Institute fellow and research scientist, and Ian Foster, the Arthur Holly Compton Distinguished Service Professor of Computer Science and Argonne Distinguished Fellow.

    The program will start in the 2018-19 academic year. Further information will be available in the upcoming academic year for those interested in applying.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 12:57 pm on August 4, 2017 Permalink | Reply
    Tags: , Clever experiment documents multi-scale fluid dynamics, , Total helicity - or the measure of when two vortex rings intertwine, U Chicago   

    From U Chicago: “Clever experiment documents multi-scale fluid dynamics” 

    U Chicago bloc

    University of Chicago

    August 3, 2017
    Steve Koppes.

    1
    Courtesy of Martin Sheeler.

    University of Chicago physicists working in the nascent field of experimental vortex dynamics have, with unexpected help from a Sharpie marker, achieved the first measurements of an elusive but fundamental property of fluid flow.

    Until now, there had been no way in the laboratory to measure the total helicity, or the measure of when two vortex rings intertwine. In their experiments, the UChicago team created thin-core vortices—the kinds found in aircraft wakes and insect flight—by producing hydrofoils using a 3-D printer.

    As luck would have it, the red Sharpie marker used to label the hydrofoils contained rhodamine dye, which fluoresced when illuminated by laser light. When the hydrofoils were placed in a water tank, the dye began to diffuse, and when the hydrofoil was accelerated, the dye got sucked into the core of the newly created vortex—a process recorded via high-speed laser scanning tomography.

    The new findings, published Aug. 3 in Science, are the first to show that helicity maintains a constant value during the flow of viscous fluids. Vortex dynamics have important applications in everyday life; meteorologists, for example, view helicity as a factor that contributes to the formation of supercell tornadoes.

    “The fact that we have some measurements for the first time that show helicity can be preserved, especially in the presence of stretching, can translate directly to those efforts,” said William Irvine, an associate professor in physics, who published the findings along with four co-authors.

    Twists and turns

    In their latest research, the physicists studied three related forms of helicity: twisting, linking and writhing. The three forms are simply different ways to describe geometrically related forms that have been twisted or stretched. Each vortex tube can be visualized as a bundle of filaments, similar to those bound together in a twisted rope.

    “If you take a piece of rope or or a telephone cord and you coil it up, then we would say that the center of this rope or telephone cord is writhing,” Irvine said. “And if we then took this thing that we coiled up and we pulled it straight, you would see twisting along its length.”

    Simulating helicity in those flows has been difficult because of the widely separated yet interconnecting scales in which they operate. Previous work had been largely theoretical and involved hypothetical, simpler fluids totally lacking in viscosity. Calculations showed that helicity was conserved in these hypothetical fluids, but viscosity emerged as a significant factor in the flow of actual fluids.

    “One of the core problems is that you need to sample or measure features of the flow that exist on very different length scales,” said Martin Scheeler, the study’s lead author, who recently completed his doctorate in physics at UChicago. The scales range from the diameter of a vortex (approximately 30 centimeters or one foot) to the diameter of its thin core (approximately one milllimeter or three hundredths of an inch).

    “You need to measure the flow inside the core as well as the overall shape evolution of that vortex,” Irvine said. “That’s quite a separation.” He characterized Scheeler’s work in overcoming the experimental challenges— simultaneously tracking the fine details of the flow while still measuring the critical larger-scale dynamics—as “a tour de force.”

    ‘It’s the wackier stuff that works’

    Irvine’s group had previously used bubbles to conduct pioneering research on the dynamics of vortices in their water-tank experiments. The helicity measurements, however, required something different, which was provided serendipitously through the Sharpie.

    Dye has long been used in vortex experiments, but less precisely. In previous experiments, the dye was placed diffusely in the tank, and then the vortices would envelope them. But the Sharpie presented an opportunity to precisely position the dye at the center of the vortices, as Scheeler painstakingly painted dots onto the entire length of the hydrofoils.

    “We hadn’t really realized that that was a possibility until we saw dye bleeding off the hydrofoil,” said Scheeler, who valued the creativity and freedom involved in designing experiments for a nascent field of physics.

    “There really is no playbook, and that’s really exciting,” he said. “You get to try out all sorts of different things, and sometimes it’s the wackier stuff that works.”

    Funding: National Science Foundation and the Packard Foundation

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 9:38 am on August 3, 2017 Permalink | Reply
    Tags: , , , , , , U Chicago   

    From U Chicago: “Dark Energy Survey reveals most precise measure of universe’s structure” 

    U Chicago bloc

    University of Chicago

    August 3, 2017

    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


    The Dark Energy Survey’s primary instrument, the 570-megapixel Dark Energy Camera, is mounted on the Blanco Telescope in Chile. UChicago, Argonne and Fermilab scientists are members of international Dark Energy Survey collaboration.

    Imagine planting a single seed and, with great precision, being able to predict the exact height of the tree that grows from it. Now imagine traveling to the future and snapping photographic proof that you were right.

    If you think of the seed as the early universe, and the tree as the universe the way it looks now, you have an idea of what the international Dark Energy Survey collaboration has just done. Scientists unveiled their most accurate measurement of the present large-scale structure of the universe at a meeting Aug. 3 at the University of Chicago-affiliated Fermi National Accelerator Laboratory. UChicago, Argonne and Fermilab scientists are members of international Dark Energy Survey collaboration.

    These measurements of the amount and “clumpiness” (or distribution) of dark matter in the present-day cosmos were made with a precision that, for the first time, rivals that of inferences from the early universe by the European Space Agency’s orbiting Planck observatory. The new Dark Energy Survey result (the tree, in the above metaphor) is close to “forecasts” made from the Planck measurements of the distant past (the seed), allowing scientists to understand more about the ways the universe has evolved over 14 billion years.

    “This result is beyond exciting,” said Fermilab’s Scott Dodelson, a professor in the Department of Astronomy and Astrophysics at UChicago and one of the lead scientists on this result, which was announced at the American Physical Society Division of Particles and Fields meeting. “For the first time, we’re able to see the current structure of the universe with the same clarity that we can see its infancy, and we can follow the threads from one to the other, confirming many predictions along the way.”

    Most notably, this result supports the theory that 26 percent of the universe is in the form of mysterious dark matter and that space is filled with an also-unseen dark energy, which makes up 70 percent and is causing the accelerating expansion of the universe.

    1
    A map of dark matter covering about one-thirtieth of the entire sky and spanning several billion light years—red regions have more dark matter than average, blue regions less dark matter. (Courtesy of Chihway Chang, the DES collaboration)

    Paradoxically, it is easier to measure the large-scale clumpiness of the universe in the distant past than it is to measure it today. In the first 400,000 years following the Big Bang, the universe was filled with a glowing gas, the light from which survives to this day. The Planck observatory’s map of this cosmic microwave background radiation gives us a snapshot of the universe at that very early time. Since then, the gravity of dark matter has pulled mass together and made the universe clumpier over time. But dark energy has been fighting back, pushing matter apart. Using the Planck map as a start, cosmologists can calculate precisely how this battle plays out over 14 billion years.

    “These first major cosmology results are a tribute to the many people who have worked on the project since it began 14 years ago,” said Dark Energy Survey Director Josh Frieman, a scientist at Fermilab and a professor in the Department of Astronomy and Astrophysics at UChicago. “It was an exciting moment when we unveiled the results to ourselves just last month, after carrying out a ‘blind’ analysis to avoid being influenced by our prejudices.”

    The Dark Energy Survey is a collaboration of more than 400 scientists from 26 institutions in seven countries. Its primary instrument is the 570-megapixel Dark Energy Camera, one of the most powerful in existence, which is able to capture digital images of light from galaxies eight billion light years from Earth. The camera was built and tested at Fermilab, the lead laboratory on the Dark Energy Survey, and is mounted on the National Science Foundation’s four-meter Blanco telescope, part of the Cerro Tololo Inter-American Observatory in Chile. The DES data are processed at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.

    Scientists are using the camera to map an eighth of the sky in unprecedented detail over five years. The fifth year of observation will begin this month. The new results draw only from data collected during the survey’s first year, which covers one-thirtieth of the sky.

    Scientists used two methods to measure dark matter. First, they created maps of galaxy positions as tracers, and second, they precisely measured the shapes of 26 million galaxies to directly map the patterns of dark matter over billions of light years, using a technique called gravitational lensing.

    Gravitational Lensing NASA/ESA

    To make these ultra-precise measurements, the team developed new ways to detect the tiny lensing distortions of galaxy images—an effect not even visible to the eye, enabling revolutionary advances in understanding these cosmic signals. In the process, they created the largest guide to spotting dark matter in the cosmos ever drawn. The new dark matter map is ten times the size of the one that the Dark Energy Survey released in 2015 and will eventually be three times larger than it is now.

    “The Dark Energy Survey has already delivered some remarkable discoveries and measurements, and they have barely scratched the surface of their data,” said Fermilab Director Nigel Lockyer. “Today’s world-leading results point forward to the great strides DES will make toward understanding dark energy in the coming years.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 12:42 pm on June 25, 2017 Permalink | Reply
    Tags: , Efimov molecules, How the first complex molecules formed in the early universe and how complex materials came into being, Prof. Cheng Chin, Quantum objects, U Chicago   

    From U Chicago: “UChicago physicists settle debate over how exotic quantum particles form” 

    U Chicago bloc

    University of Chicago

    June 22, 2017
    Carla Reiter

    New research by physicists at the University of Chicago settles a longstanding disagreement over the formation of exotic quantum particles known as Efimov molecules.

    The findings, published last month in Nature Physics, address differences between how theorists say Efimov molecules should form and the way researchers say they did form in experiments. The study found that the simple picture scientists formulated based on almost 10 years of experimentation had it wrong—a result that has implications for understanding how the first complex molecules formed in the early universe and how complex materials came into being.

    1
    Prof. Cheng Chin. No image credit.

    Efimov molecules are quantum objects formed by three particles that bind together when two particles are unable to do so. The same three particles can make molecules in an infinite range of sizes, depending on the strength of the interactions between them.

    Experiments had shown the size of an Efimov molecule was roughly proportional to the size of the atoms that comprise it—a property physicists call universality.

    “This hypothesis has been checked and rechecked multiple times in the past 10 years, and almost all the experiments suggested that this is indeed the case,” said Cheng Chin, a professor of physics at UChicago, who leads the lab where the new findings were made. “But some theorists say the real world is more complicated than this simple formula. There should be some other factors that will break this universality.“

    The new findings come down somewhere between the previous experimental findings and predictions of theorists. They contradict both and do away with the idea of universality.

    “I have to say that I am surprised,” Chin said. “This was an experiment where I did not anticipate the result before we got the data.”

    The data came from extremely sensitive experiments done with cesium and lithium atoms using techniques devised by Jacob Johansen, previously a graduate student in Chin’s lab who is now a postdoctoral fellow at Northwestern University. Krutik Patel, a graduate student at UChicago, and Brian DeSalvo, a postdoctoral researcher at UChicago, also contributed to the work.

    “We wanted to be able to say once and for all that if we didn’t see any dependence on these other properties, then there’s really something seriously wrong with the theory,” Johansen said. “If we did see dependence, then we’re seeing the breakdown of this universality. It always feels good, as a scientist, to resolve these sorts of questions.”

    Developing new techniques

    2
    Here “3” symbolizes an Efimov molecule comprised of three atoms. While all “3”s look about the same, research from the Chin group observed a tiny “3” that is clearly different. Courtesy of Cheng Chin.

    Efimov molecules are held together by quantum forces rather than by the chemical bonds that bind together familiar molecules such as H2O. The atoms are so weakly connected that the molecules can’t exist under normal conditions. Heat in a room providing enough energy to shatter their bonds.

    The Efimov molecule experiments were done at extremely low temperatures—50 billionths of a degree above absolute zero—and under the influence of a strong magnetic field, which is used to control the interaction of the atoms. When the field strength is in a particular, narrow range, the interaction between atoms intensifies and molecules form. By analyzing the precise conditions in which formation occurs, scientists can infer the size of the molecules.

    But controlling the magnetic field precisely enough to make the measurements Johansen sought is extremely difficult. Even heat generated by the electric current used to create the field was enough to change that field, making it hard to reproduce in experiments. The field could fluctuate at a level of only one part in a million—a thousand times weaker than the Earth’s magnetic field—and Johansen had to stabilize it and monitor how it changed over time.

    The key was a technique he developed to probe the field using microwave electronics and the atoms themselves.

    “I consider what Jacob did a tour de force,” Chin said. “He can control the field with such high accuracy and perform very precise measurements on the size of these Efimov molecules and for the first time the data really confirm that there is a significant deviation of the universality.”

    The new findings have important implications for understanding the development of complexity in materials. Normal materials have diverse properties, which could not have arisen if their behavior at the quantum level was identical. The three-body Efimov system puts scientists right at the point at which universal behavior disappears.

    “Any quantum system made with three or more particles is a very, very difficult problem,” Chin said. “Only recently do we really have the capability to test the theory and understand the nature of such molecules. We are making progress toward understanding these small quantum clusters. This will be a building block for understanding more complex material.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 4:24 pm on June 22, 2017 Permalink | Reply
    Tags: , Chicago Quantum Exchange to create technologically transformative ecosystem, Combining strengths in quantum information, , U Chicago   

    From U Chicago: “Chicago Quantum Exchange to create technologically transformative ecosystem” 

    U Chicago bloc

    University of Chicago

    June 20, 2017
    Steve Koppes

    1
    UChicago and affiliated laboratories to collaborate on advancing the science and engineering of quantum information. Courtesy of Nicholas Brawand

    The University of Chicago is collaborating with the U.S. Department of Energy’s Argonne National Laboratory and Fermi National Accelerator Laboratory to launch an intellectual hub for advancing academic, industrial and governmental efforts in the science and engineering of quantum information.

    This hub within the Institute for Molecular Engineering, called the Chicago Quantum Exchange, will facilitate the exploration of quantum information and the development of new applications with the potential to dramatically improve technology for communication, computing and sensing. The collaboration will include scientists and engineers from the two national labs and IME, as well as scholars from UChicago’s departments of physics, chemistry, computer science, and astronomy and astrophysics.

    Quantum mechanics governs the behavior of matter at the atomic and subatomic levels in exotic and unfamiliar ways compared to the classical physics used to understand the movements of everyday objects. The engineering of quantum phenomena could lead to new classes of devices and computing capabilities, permitting novel approaches to solving problems that cannot be addressed using existing technology.

    “The combination of the University of Chicago, Argonne National Laboratory and Fermi National Accelerator Laboratory, working together as the Chicago Quantum Exchange, is unique in the domain of quantum information science,” said Matthew Tirrell, dean and founding Pritzker Director of the Institute for Molecular Engineering and Argonne’s deputy laboratory director for science. “The CQE’s capabilities will span the range of quantum information—from basic solid-state experimental and theoretical physics, to device design and fabrication, to algorithm and software development. CQE aims to integrate and exploit these capabilities to create a quantum information technology ecosystem.”

    Serving as director of the Chicago Quantum Exchange will be David Awschalom, UChicago’s Liew Family Professor in Molecular Engineering and an Argonne senior scientist. Discussions about establishing a trailblazing quantum engineering initiative began soon after Awschalom joined the UChicago faculty in 2013 when he proposed this concept, and were subsequently developed through the recruitment of faculty and the creation of state-of-the-art measurement laboratories.

    “We are at a remarkable moment in science and engineering, where a stream of scientific discoveries are yielding new ways to create, control and communicate between quantum states of matter,” Awschalom said. “Efforts in Chicago and around the world are leading to the development of fundamentally new technologies, where information is manipulated at the atomic scale and governed by the laws of quantum mechanics. Transformative technologies are likely to emerge with far-reaching applications—ranging from ultra-sensitive sensors for biomedical imaging to secure communication networks to new paradigms for computation. In addition, they are making us re-think the meaning of information itself.”

    The collaboration will benefit from UChicago’s Polsky Center for Entrepreneurship and Innovation, which supports the creation of innovative businesses connected to UChicago and Chicago’s South Side. The CQE will have a strong connection with a major Hyde Park innovation project that was announced recently as the second phase of the Harper Court development on the north side of 53rd Street, and will include an expansion of Polsky Center activities. This project will enable the transition from laboratory discoveries to societal applications through industrial collaborations and startup initiatives.

    Companies large and small are positioning themselves to make a far-reaching impact with this new quantum technology. Alumni of IME’s quantum engineering PhD program have been recruited to work for many of these companies. The creation of CQE will allow for new linkages and collaborations with industry, governmental agencies and other academic institutions, as well as support from the Polsky Center for new startup ventures.

    This new quantum ecosystem will provide a collaborative environment for researchers to invent technologies in which all the components of information processing—sensing, computation, storage and communication—are kept in the quantum world, Awschalom said. This contrasts with today’s mainstream computer systems, which frequently transform electronic signals from laptop computers into light for internet transmission via fiber optics, transforming them back into electronic signals when they arrive at their target computers, finally to become stored as magnetic data on hard drives.

    IME’s quantum engineering program is already training a new workforce of “quantum engineers” to meet the need of industry, government laboratories and universities. The program now consists of eight faculty members and more than 100 postdoctoral scientists and doctoral students. Approximately 20 faculty members from UChicago’s Physical Sciences Division also pursue quantum research. These include David Schuster, assistant professor in physics, who collaborates with Argonne and Fermilab researchers.

    Combining strengths in quantum information

    The collaboration will rely on the distinctive strengths of the University and the two national laboratories, both of which are located in the Chicago suburbs and have longstanding affiliations with the University of Chicago.

    At Argonne, approximately 20 researchers conduct quantum-related research through joint appointments at the laboratory and UChicago. Fermilab has about 25 scientists and technicians working on quantum research initiatives related to the development of particle sensors, quantum computing and quantum algorithms.

    “This is a great time to invest in quantum materials and quantum information systems,” said Supratik Guha, director of Argonne’s Nanoscience and Technology Division and a professor of molecular engineering at UChicago. “We have extensive state-of-the-art capabilities in this area.”

    Argonne proposed the first recognizable theoretical framework for a quantum computer, work conducted in the early 1980s by Paul Benioff. Today, including joint appointees, Argonne’s expertise spans the spectrum of quantum sensing, quantum computing, classical computing and materials science.

    Argonne and UChicago already have invested approximately $6 million to build comprehensive materials synthesis facilities—called “The Quantum Factory”—at both locations. Guha, for example, has installed state-of-the-art deposition systems that he uses to layer atoms of materials needed for building quantum structures.

    “Together we will have comprehensive capabilities to be able to grow and synthesize one-, two- and three-dimensional quantum structures for the future,” Guha said. These structures, called quantum bits—qubits—serve as the building blocks for quantum computing and quantum sensing.

    2
    Illustration of near-infrared light polarizing nuclear spins in a silicon carbide chip. Courtesy of Peter Allen

    Argonne also has theorists who can help identify problems in physics and chemistry that could be solved via quantum computing. Argonne’s experts in algorithms, operating systems and systems software, led by Rick Stevens, associate laboratory director and UChicago professor in computer science, will play a critical role as well, because no quantum computer will be able to operate without connecting to a classical computer.

    Fermilab’s interest in quantum computing stems from the enhanced capabilities that the technology could offer within 15 years, said Joseph Lykken, Fermilab deputy director and senior scientist.

    “The Large Hadron Collider experiments, ATLAS and CMS, will still be running 15 years from now,” Lykken said. “Our neutrino experiment, DUNE, will still be running 15 years from now. Computing is integral to particle physics discoveries, so advances that are 15 years away in high-energy physics are developments that we have to start thinking about right now.”

    Lykken noted that almost any quantum computing technology is, by definition, a device with atomic-level sensitivity that potentially could be applied to sensitive particle physics experiments. An ongoing Fermilab-UChicago collaboration is exploring the use of quantum computing for axion detection. Axions are candidate particles for dark matter, an invisible mass of unknown composition that accounts for 85 percent of the mass of the universe.

    Another collaboration with UChicago involves developing quantum computer technology that uses photons in superconducting radio frequency cavities for data storage and error correction. These photons are light particles emitted as microwaves. Scientists expect the control and measurement of microwave photons to become important components of quantum computers.

    “We build the best superconducting microwave cavities in the world, but we build them for accelerators,” Lykken said. Fermilab is collaborating with UChicago to adapt the technology for quantum applications.

    Fermilab also has partnered with the California Institute of Technology and AT&T to develop a prototype quantum information network at the lab. Fermilab, Caltech and AT&T have long collaborated to efficiently transmit the Large Hadron Collider’s massive data sets. The project, a quantum internet demonstration of sorts, is called INQNET (INtelligent Quantum NEtworks and Technologies).

    Fermilab also is working to increase the scale of today’s quantum computers. Fermilab can contribute to this effort because quantum computers are complicated, sensitive, cryogenic devices. The laboratory has decades of experience in scaling up such devices for high-energy physics applications.

    “It’s one of the main things that we do,” Lykken said.

    See the full article here .

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  • richardmitnick 12:51 pm on June 15, 2017 Permalink | Reply
    Tags: Loneliness contributes to self-centeredness for sake of self-preservation, Targeting self-centeredness as part of an intervention to lessen loneliness may help break a positive feedback loop that maintains or worsens loneliness over time, U Chicago   

    From U Chicago: “Loneliness contributes to self-centeredness for sake of self-preservation” 

    U Chicago bloc

    University of Chicago

    June 13, 2017
    Steve Koppes

    Study finds positive feedback loop between behaviors.

    1
    New study finds positive feedback loop between loneliness and self-centeredness. No image credit.

    Research conducted over more than a decade indicates that loneliness increases self-centeredness and, to a lesser extent, self-centeredness also increases loneliness.

    The findings by researchers at the University of Chicago show such effects create a positive feedback loop between the two traits: As increased loneliness heightens self-centeredness, the latter then contributes further to enhanced loneliness.

    “If you get more self-centered, you run the risk of staying locked in to feeling socially isolated,” said John Cacioppo, the Tiffany and Margaret Blake Distinguished Service Professor in Psychology and director of the Center for Cognitive and Social Neuroscience.

    Cacioppo and co-authors Stephanie Cacioppo, assistant professor of psychiatry and behavioral science at the UChicago Pritzker School of Medicine, and Hsi Yuan Chen, a researcher at the Center for Cognitive and Social Neuroscience, published their findings in Personality and Social Psychology Bulletin on June 13.

    The researchers wrote that “targeting self-centeredness as part of an intervention to lessen loneliness may help break a positive feedback loop that maintains or worsens loneliness over time.” Their study is the first to test a prediction from the Cacioppos’ evolutionary theory that loneliness increases self-centeredness. Such research is important because, as many studies have shown, lonely people are more susceptible to a variety of physical and mental health problems as well as higher mortality rates than their non-lonely counterparts.

    The outcome that loneliness increases self-centeredness was expected, but the data showing that self-centeredness also affected loneliness was a surprise, Stephanie Cacioppo said.

    Common societal malady

    In previous research, the Cacioppos reviewed the rates of loneliness in young to older adults across the globe. Five to 10 percent of this population complained of feeling lonely constantly, frequently or all the time. Another 30 to 40 percent complained of feeling lonely constantly.

    Their latest findings are based on 11 years of data taken from 2002 to 2013 as part of the Chicago Health, Aging and Social Relations Study of middle-aged and older Hispanics, African-Americans and Caucasian men and women. The study’s random sample consisted of 229 individuals who ranged from 50 to 68 years of age at the start of the study. They were a diverse sample of randomly selected individuals drawn from the general population who varied in age, gender, ethnicity and socioeconomic status.

    Early psychological research treated loneliness as an anomalous or temporary feeling of distress that had no redeeming value or adaptive purpose. “None of that could be further from the truth,” Stephanie Cacioppo said.

    The evolutionary perspective is why. In 2006, John Cacioppo and colleagues proposed an evolutionary interpretation of loneliness based on a neuroscientific or biological approach.

    In this view, evolution has shaped the brain to incline humans toward certain emotions, thoughts and behavior. “A variety of biological mechanisms have evolved that capitalize on aversive signals to motivate us to act in ways that are essential for our reproduction or survival,” the UChicago co-authors wrote. From that perspective, loneliness serves as the psychological counterpart of physical pain.

    “Physical pain is an aversive signal that alerts us of potential tissue damange and motivates us to take care of our physical body,” the UChicago researchers wrote. Loneliness, meanwhile, is part of a warning system that motivates people to repair or replace their deficient social relationships.

    Evolution of loneliness

    The finding that loneliness tends to increase self-centeredness fits the evolutionary interpretation of loneliness. From an evolutionary-biological viewpoint, people have to be concerned with their own interests. The pressures of modern society, however, are significantly different from those that prevailed when loneliness evolved in the human species, researchers found.

    “Humans evolved to become such a powerful species, in large part due to mutual aid and protection and the changes in the brain that proved adaptive in social interactions,” John Cacioppo said. “When we don’t have mutual aid and protection, we are more likely to become focused on our own interests and welfare. That is, we become more self-centered.”

    In modern society, becoming more self-centered protects lonely people in the short term but not the long term. That’s because the harmful effects of loneliness accrue over time to reduce a person’s health and well-being.

    “This evolutionarily adaptive response may have helped people survive in ancient times, but in contemporary society may well make it harder for people to get out of feelings of loneliness,” John Cacioppo said.

    When humans are at their best, they provide mutual aid and protection, Stephanie Cacioppo added. “It isn’t that one individual is sacrificial to the other. It’s that together they do more than the sum of the parts. Loneliness undercuts that focus and really makes you focus on only your interests at the expense of others.”

    The Cacioppos have multiple loneliness studies in progress that address its social, behavioral, neural, hormonal, genetic, cellular and molecular aspects, as well as interventions.

    “Now that we know loneliness is damaging and contributing to the misery and health care costs of America, how do we reduce it?” John Cacioppo asked.

    Funding: National Institute on Aging.

    See the full article here .

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  • richardmitnick 1:15 pm on May 25, 2017 Permalink | Reply
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    From U Chicago: “World’s most sensitive dark matter detector releases first results” 

    U Chicago bloc

    University of Chicago

    May 18, 2017
    news@uchicago.edu
    (773) 702-8360
    News media only

    UChicago scientists part of international XENON collaboration

    1
    XENON1T installation in the underground hall of Laboratori Nazionali del Gran Sasso. The three story building on the right houses various auxiliary systems. The cryostat containing the LXeTPC is located inside the large water tank on the left. Photo by Roberto Corrieri and Patrick De Perio

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    2
    Scientists assembling the XENON1T time projection chamber. Photo by Enrico Sacchetti

    Scientists behind XENON1T, the largest dark matter experiment of its kind ever built, are encouraged by early results, describing them as the best so far in the search for dark matter.

    Dark matter is one of the basic constituents of the universe, five times more abundant than ordinary matter. Several astronomical measurements have corroborated the existence of dark matter, leading to an international effort to observe it directly. Scientists are trying to detect dark matter particle interacting with ordinary matter through the use of extremely sensitive detectors. Such interactions are so feeble that they have escaped direct detection to date, forcing scientists to build detectors that are more and more sensitive and have extremely low levels of radioactivity.

    On May 18, the XENON Collaboration released results from a first, 30-day run of XENON1T, showing the detector has a record low radioactivity level, many orders of magnitude below surrounding material on earth.

    “The care that we put into every single detail of the new detector is finally paying back,” said Luca Grandi, assistant professor in physics at the University of Chicago and member of the XENON Collaboration. “We have excellent discovery potential in the years to come because of the huge dimension of XENON1T and its incredibly low background. These early results already are allowing us to explore regions never explored before.”

    The XENON Collaboration consists of 135 researchers from the United States, Germany, Italy, Switzerland, Portugal, France, the Netherlands, Israel, Sweden and the United Arab Emirates, who hope to one day confirm dark matter’s existence and shed light on its mysterious properties.

    Located deep below a mountain in central Italy, XENON1T features a 3.2-ton xenon dual-phase time projection chamber. This central detector sits fully submersed in the middle of the water tank, in order to shield it from natural radioactivity in the cavern. A cryostat helps keep the xenon at a temperature of minus-95 degrees Celsius without freezing the surrounding water. The mountain above the laboratory further shields the detector, preventing it from being perturbed by cosmic rays.

    But shielding from the outer world is not enough, since all materials on Earth contain tiny traces of natural radioactivity. Thus extreme care was taken to find, select and process the materials making up the detector to achieve the lowest possible radioactive content. This allowed XENON1T to achieve record “silence” necessary to detect the very weak output of dark matter.

    A particle interaction in the one-ton central core of the time projection chamber leads to tiny flashes of light. Scientists record and study these flashes to infer the position and the energy of the interacting particle—and whether it might be dark matter.

    Despite the brief 30-day science run, the sensitivity of XENON1T has already overcome that of any other experiment in the field probing unexplored dark matter territory.

    “For the moment we do not see anything unexpected, so we set new constraints on dark matter properties,” Grandi said. “But XENON1T just started its exciting journey and since the end of the 30-day science run, we have been steadily accumulating new data.”

    UChicago central to international collaboration

    Grandi’s group is very active within XENON1T, and it is contributing to several aspects of the program. After its initial involvement in the preparation, assembly and early operations of the liquid xenon chamber, the group shifted its focus in the last several months to the development of the computing infrastructure and to data analysis.

    “Despite its low background, XENON1T is producing a large amount of data that needs to be continuously processed,” said Evan Shockley, a graduate student working with Grandi. “The raw data from the detector are directly transferred from Gran Sasso Laboratory to the University of Chicago, serving as the unique distribution point for the entire collaboration.”

    The framework, developed in collaboration with a group led by Robert Gardner, senior fellow at the Computation Institute, allows for the processing of data, both on local and remote resources belonging to the Open Science Grid. The involvement of UChicago’s Research Computing Center including Director Birali Runesha allows members of the collaboration all around the world to access processed data for high-level analyses.

    Grandi’s group also has been heavily involved in the analysis that led to this first result. Christopher Tunnell, a fellow at the Kavli Institute for Cosmological Physics, is one of the two XENON1T analysis coordinators and corresponding author of the result. Recently, UChicago hosted about 25 researchers for a month to perform the analyses that led to the first results.

    “It has been a large, concentrated effort and seeing XENON1T back on the front line makes me forget the never-ending days spent next to my colleagues to look at plots and distributions,“ Tunnell said. “There is no better thrill than leading the way in our knowledge of dark matter for the coming years.”

    See the full article here .

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  • richardmitnick 1:19 pm on February 2, 2017 Permalink | Reply
    Tags: , , , Primitive achondrites, U Chicago   

    From U Chicago: “Today’s rare meteorites were common 466 million years ago, study finds” 

    U Chicago bloc

    University of Chicago

    January 26, 2017
    Kate Golembiewski

    1
    Artist’s rendering of the space collision 466 million years ago that gave rise to many of the meteorites falling to Earth today.
    Illustration by Don Davis/Southwest Research Institute

    About 466 million years ago, there was a giant collision in outer space. Something hit an asteroid and broke it apart, sending chunks of rock falling to Earth as meteorites. But what kinds of meteorites were making their way to Earth before that collision?

    In a study published Jan. 23 in Nature Astronomy, scientists tackled that question by creating the first reconstruction of the distribution of meteorite types before the collision. They discovered that most of the meteorites falling to Earth today are rare, while many meteorites that are rare today were common before the collision.

    “We found that the meteorite flux—the variety of meteorites falling to Earth—was very, very different from what we see today,” said Philipp Heck, associate professor of geophysical sciences at the University of Chicago, the paper’s lead author. “Looking at the kinds of meteorites that have fallen to Earth in the last hundred million years doesn’t give you a full picture. It would be like looking outside on a snowy day and concluding that every day is snowy, even though it’s not snowy in the summer.”

    Meteorites are pieces of rock that have fallen to Earth from outer space. They’re formed from the debris of collisions between bodies like asteroids, moons and even planets. There are many different types of meteorites, which reflect the different compositions of their parent bodies. By studying the different meteorites that have made their way to Earth, scientists can develop a better understanding of how the basic building blocks of the solar system formed and evolved.

    “Before this study, we knew almost nothing about the meteorite flux to Earth in geological deep time,” said co-author Birger Schmitz, professor of nuclear physics at Lund University. “The conventional view is that the solar system has been very stable over the past 500 million years. So it is quite surprising that the meteorite flux at 467 million years ago was so different from (that of) the present.”

    To learn what the meteorite flux was like before the big collision event, Heck and his colleagues analyzed meteorites that fell more than 466 million years ago. Such finds are rare, but the team was able to look at micrometeorites—tiny specks of space-rock less than 2 millimeters in diameter that fell to Earth. They are less rare. Heck’s Swedish and Russian colleagues retrieved samples of rock from an ancient seafloor exposed in a Russian river valley that contained micrometeorites. They then dissolved almost 600 pounds of the rocks in acid so that only microscopic chromite crystals remained.

    Not having changed during hundreds of millions of years, the crystals revealed the nature of meteorites over time. Analysis of their chemical makeup showed that the meteorites and micrometeorites that fell earlier than 466 million years ago are different from the ones that have fallen since. A full 34 percent of the pre-collision meteorites belong to a meteorite type called primitive achondrites; today, only 0.45 percent of the meteorites that land on Earth are this type.

    Other micrometeorites sampled turned out to be relics from Vesta—the brightest asteroid visible from Earth, which underwent its own collision event over a billion years ago.

    Meteorite delivery from the asteroid belt to the Earth is a little like observing landslides started at different times on a mountainside, said co-author William Bottke, senior research scientist at the Southwest Research Institute. “Today, the rocks reaching the bottom of the mountain might be dominated by a few recent landslides. Going back in time, however, older landslides should be more important. The same is true for asteroid breakup events; some younger ones dominate the current meteorite flux, while in the past older ones dominated.”

    “Knowing more about the different kinds of meteorites that have fallen over time gives us a better understanding of how the asteroid belt evolved and how different collisions happened,” said Heck, an associate curator of meteoritics and polar studies at the Field Museum of Natural History. “Ultimately, we want to study more windows in time, not just the area before and after this collision. That will deepen our knowledge of how different bodies in our solar system formed and interact with each other.”

    Funding: European Research Council and Tawani Foundation

    See the full article here .

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    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
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