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  • richardmitnick 7:48 pm on April 1, 2021 Permalink | Reply
    Tags: "A Search for Knowledge That Led Andrea Ghez to a Nobel Prize", , , , , , UCLA   

    From UCLA : “A Search for Knowledge That Led Andrea Ghez to a Nobel Prize” 


    From UCLA

    March 24, 2021
    Wayne Lewis
    Photos by Spencer Lowell

    How the fourth woman to win the prize in physics found the answer to a mystery in the stars.

    1
    Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the Galactic Center Group, won the Nobel Prize in physics last October.

    ANDREA GHEZ LOVES A GOOD MYSTERY.

    In an unknown radio signal at the heart of the Milky Way, she found a grand one. Since it was first detected in 1931, astronomers have wondered about the source, which was ultimately named Sagittarius A* (said aloud as “A-star”). Was it a cluster of dark stars? Some undiscovered particle? Or a single, gigantic black hole?

    For more than 25 years at UCLA, Ghez pursued — and then confirmed — the hypothesis that the object is a supermassive black hole, with a mass 4 million times that of our sun. Her work has revealed new knowledge about our galactic neighborhood, shaken up what has been understood about the evolution of stars and galaxies, and created a test bed for our physical understanding of the universe.

    This is not a story of “eureka” moments, although there have been spikes of excitement.

    Rather, it’s a tale of being persistent, accruing data, analyzing that data carefully and improving our view out into the endless dark.

    “Hard problems require patience,” says Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the Galactic Center Group. “If it were easy, it would have already been done. Moving the frontier of knowledge forward is just hard work.”

    Among her accomplishments, Ghez has been the recipient of a MacArthur Fellowship (often called the “genius grant”), and she was the first woman to receive the prestigious Crafoord Prize in astronomy.

    Last October, when Ghez won the Nobel Prize in physics, she was only the fourth woman to take the prize in that category and the first for astrophysics.

    ________________________________________________________________________________________________________________________________
    The Virtues of Ghez

    Colleagues, mentors and protégés of Andrea Ghez weigh in about the ingredients for her Nobel-winning science.

    VISION “She represents the epitome of leadership, and that is what got her to where she is today. As long as I’ve known Andrea, she has been strongly focused on her goals and has always had the take-charge attitude and the personal skills to bring others along with her.”

    — Mark Morris, UCLA professor of astronomy and astrophysics

    TENACITY AND PRECISION “When confronted with difficulties as a graduate student, she always picked herself up again. And the rigor of her work is really quite phenomenal.”

    — Anneila Sargent, Caltech professor emeritus

    PASSION “Andrea loves science so much. I’ve never seen anybody more excited about the science that she’s doing. She was right in there with her students all the time because she’s into the details, the puzzle and trying to work out all these little bits and pieces.”

    — Quinn Konopacky ’03, M.S. ’05, Ph.D. ’09, assistant professor of physics at UC San Diego

    POSITIVITY “Andrea is very upbeat. Her outgoing personality really helps others in the group feel comfortable speaking up and contributing.”

    — Shoko Sakai, UCLA associate researcher

    ________________________________________________________________________________________________________________________________

    EINSTEIN WAS WRONG

    Although his theory of general relativity predicted black holes, Albert Einstein thought they didn’t exist in the real world. Indeed, the mind strains to comprehend the concept. Resulting from the death of enormous stars, black holes are infinitesimally small and infinitely dense. Inside them, time folds back on itself. Their gravity is so compelling that not even light can escape. In other words, Ghez was looking for something that, by definition, can’t be seen.

    Sagittarius A* is painted instead through the effects of its gravity, in light and heat sent out by surrounding stars 26,000 years ago, during humankind’s Stone Age. Stitching together a quarter-century’s worth of data points, Ghez and her team have brought the stars’ looping dance to life in a stop-motion movie that reveals a bit more about life, the universe and everything.

    “Her group’s discoveries are a continuing sequence of steppingstones that go farther and deeper into new science,” says Mark Morris, a UCLA professor of astronomy and astrophysics who, along with professor emeritus Eric Becklin, has been Ghez’s longtime partner in the Galactic Center Group. “Andrea’s strong focus to stay the course for the past 25 years has been necessary for going as far as she has.”

    THE SKY IS NOT THE LIMIT

    Ghez grew up in Chicago, the eldest of three sisters. Among her earliest memories was Neil Armstrong’s moonwalk, which helped set her sense of scale — and of what was possible — beyond earthly bounds. Her father, an economics professor, stoked her love of math and puzzles with logic games from the time she was a small child. She also watched her mother advance from working as a secretary at an art gallery to becoming its longtime director.

    “She was just a great role model of somebody who had kids and had this really interesting, exciting career,” Ghez recalls. “I never doubted that I could have an interesting career myself.” An interesting career she has built indeed, while also raising two sons, now teenagers.

    2
    A close-up of Andrea’s Nobel Prize medal.

    Even before she set her sights on the galactic stage, she showed the will to cheerfully defy expectations in the face of naysayers. Some told her that a girl couldn’t get into the Massachusetts Institute of Technology. But that didn’t stop her from earning her bachelor’s degree in physics there.

    The same doubting voices spouted off again when she applied to Caltech’s doctoral program. But Ghez prevailed, studying young stars with Gerry Neugebauer, a pioneer of infrared astronomy — an approach that was vital to her later work tracking stellar arcs around Sagittarius A*. After a year as a Hubble postdoctoral research fellow at the University of Arizona, she began her time at UCLA in 1994.

    “There’s a reason why I’ve stayed at UCLA all these years,” she says. “To be part of an institution that has been so supportive has made a world of difference.”

    NEW WAYS OF SEEING

    Perceptually, the center of the galaxy appears in a sliver of our sky no wider than a human hair. Ghez looks out into it using the world’s largest telescope system, the twin 10-meter instruments at the W. M. Keck Observatory in Hawaii.

    W.M. Keck Observatory, two ten meter telescopes operated by California Institute of Technology(US) and the University of California(US), Maunakea Hawaii USA, altitude 4,207 m (13,802 ft). Credit: Caltech.

    Access to the telescopes, which are co-owned by the University of California (US), is another reason why she describes her UCLA appointment as a dream job. Observing used to require regular trips to Hawaii, but in recent years, she and her team have been able to observe remotely from L.A.

    Even with powerful telescopes, turbulence in Earth’s atmosphere smears the view of the galactic center into a flickering haze. To see clearly, Ghez has been a chronic early adopter of new technologies, enabled by a tight partnership with Keck Observatory engineers. First, it was software-based speckle imaging, then a succession of advances in adaptive optics, with lasers guiding the telescopes’ segmented mirrors to adjust 1,000 times per second to correct for atmospheric turbulence.

    UCO Keck Laser Guide Star Adaptive Optics on two 10 meter Keck Observatory telescopes, Maunakea Hawaii USA, altitude 4,207 m (13,802 ft).

    Of course, novelty brings risk. In 1995, when Ghez was a new faculty member, she proposed using speckle imaging but was turned down. However, as her favorite saying goes, “every challenge is an opportunity.” Ghez persisted — by borrowing telescope time from another astronomer and writing a second proposal that better explained her plans — and she successfully launched the project.

    Telescope time is a precious commodity. During the late spring to summer, when Ghez and her team observe the “neighborhood” at the center of the galaxy, each night is special. The 3,000 or so stars whose routes they trace will never be in the same configuration again. Meticulous preparation goes into an observing run, as technical difficulties can sabotage the collection of data — the researchers’ crucial raw material.

    TWO WAYS TO CREATE NEW KNOWLEDGE

    Essential to Ghez’s quarter-century longitudinal star study is the work of graduate students and postdoctoral scholars. Her mentorship offers them independence to follow their scientific instincts, while nurturing the shorter-term projects they lead.

    “One of the wonderful things about doing research in the university setting is that you’re creating new knowledge — both through the research and by training new scientists,” Ghez says. “So much of training young scientists is about teaching them to find a good problem — one that’s solvable, one that you can sink your teeth into.”

    Something else they learn is the need to ensure that their analysis is ironclad. An anomaly can mean a major discovery — or a major mistake.

    “Andrea really shaped the way I think about data, about how important it is to get the science right rather than get it out fast,” says Tuan Do M.S. ’06, Ph.D. ’10, a UCLA assistant professor of astronomy and deputy director of the Galactic Center Group.

    Ghez has publicly reflected on how winning the Nobel Prize also means the responsibility of being a role model. Her protégés might say that she’s well-practiced.

    “I learned a lot about how to be a good scientist from her,” says Angelle Tanner M.S. ’98, Ph.D. ’04, who is now an associate professor at Mississippi State University. “She’s the quintessential scientist, and her approach was inspirational.”

    EINSTEIN WAS RIGHT

    Andrea Ghez’s favorite star is one named S0-2, which takes just 16 years to complete a single revolution around Sagittarius A* — revealing clues to cosmic truths on a human timeline.

    Star S0-2 Andrea Ghez Keck/UCLA Galactic Center Group (US) at SGR A*, the supermassive black hole at the center of the Milky Way.

    Star S2 near SGR A* at the center of the milky Way studied by Richard Genzel of MPG Institute for extraterrestrial Physics (DE).

    Richard Genzel was a co-winner of the Nobel Prize along with Andrea Ghez and Roger Penrose
    3
    Genzel did his work at The European Southern Observatory (EU) using the Very Large Telescope at Cerro Paranal.

    Sgr A* from ESO VLT.

    European Southern Observatory(EU) , Very Large Telescope at Cerro Paranal in the Atacama Desert •ANTU (UT1; The Sun ) •KUEYEN (UT2; The Moon ) •MELIPAL (UT3; The Southern Cross ), and •YEPUN (UT4; Venus – as evening star). Elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo.


    Breakthroughs in her Nobel-winning endeavor, as recently as 2019, derived from observations of S0-2. Using its complete orbit to directly measure the supermassive black hole’s gravity, Ghez and her team showed experimental proof for general relativity — although the extremes of gravity promise an eventual breakdown in theory.

    “Einstein’s right, at least for now,” she said at the time.

    The same study also produced the strongest proof yet that Sagittarius A* is a supermassive black hole. Although alternative theories had been discarded by 2008, the findings confined its immense mass to an area a bit smaller than our solar system, increasing the strength of evidence by a factor of 10 million.

    WITH NEW ANSWERS, MORE QUESTIONS

    The Nobel Prize isn’t an endpoint for Ghez and her team. There are too many new questions borne of each advance. Their next steps could influence human understanding of nature on a fundamental level.

    Black holes have immense gravity — central to relativity — while being unimaginably tiny, suggesting that the eccentric rules of quantum mechanics apply. So the tantalizing possibility arises of using insights about Sagittarius A* to inform a new physics that bridges the two, which are currently incompatible.

    The stars’ orbits may also offer a way to detect dark matter, the unseen and little-understood stuff that accounts for most mass in the universe. Another enigma surrounds starlike objects that distort strangely as they pass close to Sagittarius A*.

    Meanwhile, the burgeoning field of gravitational wave astronomy is profiling violent cosmic events, such as the collision of binary stars like those at the galactic center, suggesting an opportunity to match those ripples in space-time with infrared observation of the galaxy’s core. Ghez also seeks to untangle the paradox of youth — the finding that stars close to Sagittarius A* are far younger than current models predict.

    Tackling all of this, she and her team continue to push the technological envelope and are playing a role in realizing the next generation of even bigger telescopes — all the better to see more stars, more clearly.

    After all, the fun of mysteries is in the solving.

    “Black holes are a big puzzle,” Ghez says. “They’re a fascinating, intriguing puzzle.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

    The University of California, Los Angeles(US) (UCLA) is a public land-grant research university in Los Angeles, California. UCLA traces its early origins back to 1882 as the southern branch of the California State Normal School (now San Jose State University (US)). It became the Southern Branch of the University of California in 1919, making it the second-oldest (after University of California at Berkeley(US)) of the 10-campus University of California (US) system.

    UCLA offers 337 undergraduate and graduate degree programs in a wide range of disciplines, enrolling about 31,500 undergraduate and 12,800 graduate students. UCLA had 168,000 applicants for Fall 2021, including transfer applicants, making the school the most applied-to of any American university.

    The university is organized into six undergraduate colleges; seven professional schools; and four professional health science schools. The undergraduate colleges are the College of Letters and Science; Samueli School of Engineering; School of the Arts and Architecture; Herb Alpert School of Music; School of Theater, Film and Television; and School of Nursing.

    UCLA is called a “Public Ivy”, and is ranked among the best public universities in the United States by major college and university rankings. This includes one ranking that has UCLA as the top public university in the United States in 2021. As of October 2020, 25 Nobel laureates; three Fields Medalists; five Turing Award winners; and two Chief Scientists of the U.S. Air Force have been affiliated with UCLA as faculty; researchers or alumni. Among the current faculty members, 55 have been elected to the National Academy of Sciences (US); 28 to the National Academy of Engineering (US); 39 to the Institute of Medicine; and 124 to the American Academy of Arts and Sciences (US). The university was elected to the Association of American Universities (US) in 1974.

    UCLA student-athletes compete as the Bruins in the Pac-12 Conference. The Bruins have won 129 national championships, including 118 NCAA team championships- more than any other university except Stanford University (US), whose athletes have won 126. UCLA students, coaches, and staff have won 251 Olympic medals: 126 gold; 65 silver; and 60 bronze. UCLA student-athletes have competed in every Olympics since 1920 with one exception (1924) and have won a gold medal in every Olympics the U.S. participated in since 1932.

    History

    In March 1881, at the request of state senator Reginaldo Francisco del Valle, the California State Legislature authorized the creation of a southern branch of the California State Normal School (now San José State University) in downtown Los Angeles to train teachers for the growing population of Southern California. The Los Angeles branch of the California State Normal School opened on August 29, 1882, on what is now the site of the Central Library of the Los Angeles Public Library system. The facility included an elementary school where teachers-in-training could practice their technique with children. That elementary school is related to the present day UCLA Lab School. In 1887, the branch campus became independent and changed its name to Los Angeles State Normal School.

    In 1914, the school moved to a new campus on Vermont Avenue (now the site of Los Angeles City College (US)) in East Hollywood. In 1917, UC Regent Edward Augustus Dickson, the only regent representing the Southland at the time and Ernest Carroll Moore- Director of the Normal School, began to lobby the State Legislature to enable the school to become the second University of California campus, after UC Berkeley. They met resistance from UC Berkeley alumni, Northern California members of the state legislature, and Benjamin Ide Wheeler- President of the University of California from 1899 to 1919 who were all vigorously opposed to the idea of a southern campus. However, David Prescott Barrows the new President of the University of California did not share Wheeler’s objections.

    On May 23, 1919, the Southern Californians’ efforts were rewarded when Governor William D. Stephens signed Assembly Bill 626 into law which acquired the land and buildings and transformed the Los Angeles Normal School into the Southern Branch of the University of California. The same legislation added its general undergraduate program- the Junior College. The Southern Branch campus opened on September 15 of that year offering two-year undergraduate programs to 250 Junior College students and 1,250 students in the Teachers College under Moore’s continued direction. Southern Californians were furious that their so-called “branch” provided only an inferior junior college program (mocked at the time by University of Southern California students as “the twig”) and continued to fight Northern Californians (specifically, Berkeley) for the right to three and then four years of instruction culminating in bachelor’s degrees. On December 11, 1923 the Board of Regents authorized a fourth year of instruction and transformed the Junior College into the College of Letters and Science which awarded its first bachelor’s degrees on June 12, 1925.

    Under UC President William Wallace Campbell, enrollment at the Southern Branch expanded so rapidly that by the mid-1920s the institution was outgrowing the 25 acre Vermont Avenue location. The Regents searched for a new location and announced their selection of the so-called “Beverly Site”—just west of Beverly Hills—on March 21, 1925 edging out the panoramic hills of the still-empty Palos Verdes Peninsula. After the athletic teams entered the Pacific Coast conference in 1926 the Southern Branch student council adopted the nickname “Bruins” a name offered by the student council at UC Berkeley. In 1927, the Regents renamed the Southern Branch the University of California at Los Angeles (the word “at” was officially replaced by a comma in 1958 in line with other UC campuses). In the same year the state broke ground in Westwood on land sold for $1 million- less than one-third its value- by real estate developers Edwin and Harold Janss for whom the Janss Steps are named. The campus in Westwood opened to students in 1929.

    The original four buildings were the College Library (now Powell Library); Royce Hall; the Physics-Biology Building (which became the Humanities Building and is now the Renee and David Kaplan Hall); and the Chemistry Building (now Haines Hall) arrayed around a quadrangular courtyard on the 400 acre (1.6 km^2) campus. The first undergraduate classes on the new campus were held in 1929 with 5,500 students. After lobbying by alumni; faculty; administration and community leaders UCLA was permitted to award the master’s degree in 1933 and the doctorate in 1936 against continued resistance from UC Berkeley.

    Maturity as a university

    During its first 32 years UCLA was treated as an off-site department of UC. As such its presiding officer was called a “provost” and reported to the main campus in Berkeley. In 1951 UCLA was formally elevated to co-equal status with UC Berkeley, and its presiding officer Raymond B. Allen was the first chief executive to be granted the title of chancellor. The appointment of Franklin David Murphy to the position of Chancellor in 1960 helped spark an era of tremendous growth of facilities and faculty honors. By the end of the decade UCLA had achieved distinction in a wide range of subjects. This era also secured UCLA’s position as a proper university and not simply a branch of the UC system. This change is exemplified by an incident involving Chancellor Murphy, which was described by him:

    I picked up the telephone and called in from somewhere and the phone operator said, “University of California.” And I said, “Is this Berkeley?” She said, “No.” I said, “Well who have I gotten to?” “UCLA.” I said, “Why didn’t you say UCLA?” “Oh”, she said, “we’re instructed to say University of California.” So the next morning I went to the office and wrote a memo; I said, “Will you please instruct the operators, as of noon today, when they answer the phone to say, ‘UCLA.'” And they said, “You know they won’t like it at Berkeley.” And I said, “Well, let’s just see. There are a few things maybe we can do around here without getting their permission.”

    Recent history

    On June 1, 2016 two men were killed in a murder-suicide at an engineering building in the university. School officials put the campus on lockdown as Los Angeles Police Department officers including SWAT cleared the campus.

    In 2018, a student-led community coalition known as “Westwood Forward” successfully led an effort to break UCLA and Westwood Village away from the existing Westwood Neighborhood Council and form a new North Westwood Neighborhood Council with over 2,000 out of 3,521 stakeholders voting in favor of the split. Westwood Forward’s campaign focused on making housing more affordable and encouraging nightlife in Westwood by opposing many of the restrictions on housing developments and restaurants the Westwood Neighborhood Council had promoted.

    Academics

    Divisions

    Undergraduate

    College of Letters and Science
    Social Sciences Division
    Humanities Division
    Physical Sciences Division
    Life Sciences Division
    School of the Arts and Architecture
    Henry Samueli School of Engineering and Applied Science (HSSEAS)
    Herb Alpert School of Music
    School of Theater, Film and Television
    School of Nursing
    Luskin School of Public Affairs

    Graduate

    Graduate School of Education & Information Studies (GSEIS)
    School of Law
    Anderson School of Management
    Luskin School of Public Affairs
    David Geffen School of Medicine
    School of Dentistry
    Jonathan and Karin Fielding School of Public Health
    Semel Institute for Neuroscience and Human Behavior
    School of Nursing

    Research

    UCLA is classified among “R1: Doctoral Universities – Very high research activity” and had $1.32 billion in research expenditures in FY 2018.

     
  • richardmitnick 8:07 pm on March 31, 2021 Permalink | Reply
    Tags: "Century-old problem solved with first-ever 3D atomic imaging of an amorphous solid", , Because amorphous solids aren’t assembled in rigid repetitive atomic structures like crystals they have defied researchers’ ability to determine their atomic structure with precision., , Direct knowledge of amorphous structures at this level is a game changer for the physical sciences., Glass; rubber; and plastics all belong to a class of matter called amorphous solids., , UCLA, UCLA-led study captures the structure of metallic glass.   

    From UCLA : “Century-old problem solved with first-ever 3D atomic imaging of an amorphous solid” 

    From UCLA

    March 31, 2021
    Wayne Lewis

    Media Contact
    Marc Roseboro
    310-794-4612
    marc@cnsi.ucla.edu

    UCLA-led study captures the structure of metallic glass.

    1
    At left, an experimental 3D atomic model of a metallic glass nanoparticle, 8 nanometers in diameter. Right, the 3D atomic packing of a supercluster within the structure, with differently colored balls representing different types of atoms. Credit: Yao Yang and Jianwei “John” Miao/UCLA.

    Glass; rubber; and plastics all belong to a class of matter called amorphous solids. And in spite of how common they are in our everyday lives, amorphous solids have long posed a challenge to scientists.

    Since the 1910s, scientists have been able to map in 3D the atomic structures of crystals, the other major class of solids, which has led to myriad advances in physics; chemistry; biology; materials science geology; nanoscience; drug discovery and more. But because amorphous solids aren’t assembled in rigid repetitive atomic structures like crystals are they have defied researchers’ ability to determine their atomic structure with the same level of precision.

    Until now, that is.

    A UCLA-led study in the journal Nature reports on the first-ever determination of the 3D atomic structure of an amorphous solid — in this case, a material called metallic glass.

    “We know so much about crystals yet most of the matter on Earth is non-crystalline and we know so little about their atomic structure,” said the study’s senior author, Jianwei “John” Miao, a UCLA professor of physics and astronomy and member of the California NanoSystems Institute at UCLA.

    Observing the 3D atomic arrangement of an amorphous solid has been Miao’s dream since he was a graduate student. That dream has now been realized, after 22 years of relentless pursuit.

    “This study just opened a new door,” he said.

    Metallic glasses tend to be both stronger and more shapeable than standard crystalline metals, and they are used today in products ranging from electrical transformers to high-end golf clubs and the housings for Apple laptops and other electronic devices. Understanding the atomic structure of metallic glasses could help engineers design even better versions of these materials, for an even wider array of applications.


    Determining the three-dimensional atomic structure of an amorphous solid
    The researchers used a technique called atomic electron tomography, a type of 3D imaging pioneered by Miao and collaborators. The approach involves beaming electrons through a sample and collecting an image on the other side. The sample is rotated so that measurements can be taken from multiple angles, yielding data that is stitched together to produce a 3D image.

    “We combined state-of-the-art electron microscopy with powerful algorithms and analysis techniques to study structures down to the level of single atoms,” said co-author Peter Ercius, a staff scientist at DOE’s Lawrence Berkeley National Laboratory’s (US) Molecular Foundry, where the experiment was conducted.

    “Direct knowledge of amorphous structures at this level is a game changer for the physical sciences.”

    The researchers examined a sample of metallic glass about 8 nanometers in diameter, made of eight different metals. (A nanometer is one-billionth of a meter.) Using 55 atomic electron tomography images, Miao and colleagues created a 3D map of the approximately 18,000 atoms that made up the nanoparticle.

    Because amorphous solids have been so difficult to characterize, the researchers expected the atoms to be arranged chaotically. And although about 85% of the atoms were in a disordered arrangement, the researchers were able to identify pockets where a fraction of atoms coalesced into ordered superclusters. The finding demonstrated that even within an amorphous solid, the arrangement of atoms is not completely random.

    Miao acknowledged one limitation of the research, borne of the limits of electron microscopy itself. Some of the metal atoms were so similar in size that electron imaging couldn’t distinguish between them. For the purposes of the study, the researchers grouped the metals into three categories, uniting neighbors from the periodic table of elements: cobalt and nickel in the first category; ruthenium, rhodium, palladium and silver in the second; and iridium and platinum in the third.

    The research was supported primarily by the STROBE National Science Foundation Science and Technology Center, of which Miao is deputy director, and in part by the U.S. Department of Energy.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    The University of California, Los Angeles(US) (UCLA) is a public land-grant research university in Los Angeles, California. UCLA traces its early origins back to 1882 as the southern branch of the California State Normal School (now San Jose State University (US)). It became the Southern Branch of the University of California in 1919, making it the second-oldest (after University of California at Berkeley(US)) of the 10-campus University of California (US) system.

    UCLA offers 337 undergraduate and graduate degree programs in a wide range of disciplines, enrolling about 31,500 undergraduate and 12,800 graduate students. UCLA had 168,000 applicants for Fall 2021, including transfer applicants, making the school the most applied-to of any American university.

    The university is organized into six undergraduate colleges; seven professional schools; and four professional health science schools. The undergraduate colleges are the College of Letters and Science; Samueli School of Engineering; School of the Arts and Architecture; Herb Alpert School of Music; School of Theater, Film and Television; and School of Nursing.

    UCLA is called a “Public Ivy”, and is ranked among the best public universities in the United States by major college and university rankings. This includes one ranking that has UCLA as the top public university in the United States in 2021. As of October 2020, 25 Nobel laureates; three Fields Medalists; five Turing Award winners; and two Chief Scientists of the U.S. Air Force have been affiliated with UCLA as faculty; researchers or alumni. Among the current faculty members, 55 have been elected to the National Academy of Sciences (US); 28 to the National Academy of Engineering (US); 39 to the Institute of Medicine; and 124 to the American Academy of Arts and Sciences (US). The university was elected to the Association of American Universities (US) in 1974.

    UCLA student-athletes compete as the Bruins in the Pac-12 Conference. The Bruins have won 129 national championships, including 118 NCAA team championships- more than any other university except Stanford University (US), whose athletes have won 126. UCLA students, coaches, and staff have won 251 Olympic medals: 126 gold; 65 silver; and 60 bronze. UCLA student-athletes have competed in every Olympics since 1920 with one exception (1924) and have won a gold medal in every Olympics the U.S. participated in since 1932.

    History

    In March 1881, at the request of state senator Reginaldo Francisco del Valle, the California State Legislature authorized the creation of a southern branch of the California State Normal School (now San José State University) in downtown Los Angeles to train teachers for the growing population of Southern California. The Los Angeles branch of the California State Normal School opened on August 29, 1882, on what is now the site of the Central Library of the Los Angeles Public Library system. The facility included an elementary school where teachers-in-training could practice their technique with children. That elementary school is related to the present day UCLA Lab School. In 1887, the branch campus became independent and changed its name to Los Angeles State Normal School.

    In 1914, the school moved to a new campus on Vermont Avenue (now the site of Los Angeles City College (US)) in East Hollywood. In 1917, UC Regent Edward Augustus Dickson, the only regent representing the Southland at the time and Ernest Carroll Moore- Director of the Normal School, began to lobby the State Legislature to enable the school to become the second University of California campus, after UC Berkeley. They met resistance from UC Berkeley alumni, Northern California members of the state legislature, and Benjamin Ide Wheeler- President of the University of California from 1899 to 1919 who were all vigorously opposed to the idea of a southern campus. However, David Prescott Barrows the new President of the University of California did not share Wheeler’s objections.

    On May 23, 1919, the Southern Californians’ efforts were rewarded when Governor William D. Stephens signed Assembly Bill 626 into law which acquired the land and buildings and transformed the Los Angeles Normal School into the Southern Branch of the University of California. The same legislation added its general undergraduate program- the Junior College. The Southern Branch campus opened on September 15 of that year offering two-year undergraduate programs to 250 Junior College students and 1,250 students in the Teachers College under Moore’s continued direction. Southern Californians were furious that their so-called “branch” provided only an inferior junior college program (mocked at the time by University of Southern California students as “the twig”) and continued to fight Northern Californians (specifically, Berkeley) for the right to three and then four years of instruction culminating in bachelor’s degrees. On December 11, 1923 the Board of Regents authorized a fourth year of instruction and transformed the Junior College into the College of Letters and Science which awarded its first bachelor’s degrees on June 12, 1925.

    Under UC President William Wallace Campbell, enrollment at the Southern Branch expanded so rapidly that by the mid-1920s the institution was outgrowing the 25 acre Vermont Avenue location. The Regents searched for a new location and announced their selection of the so-called “Beverly Site”—just west of Beverly Hills—on March 21, 1925 edging out the panoramic hills of the still-empty Palos Verdes Peninsula. After the athletic teams entered the Pacific Coast conference in 1926 the Southern Branch student council adopted the nickname “Bruins” a name offered by the student council at UC Berkeley. In 1927, the Regents renamed the Southern Branch the University of California at Los Angeles (the word “at” was officially replaced by a comma in 1958 in line with other UC campuses). In the same year the state broke ground in Westwood on land sold for $1 million- less than one-third its value- by real estate developers Edwin and Harold Janss for whom the Janss Steps are named. The campus in Westwood opened to students in 1929.

    The original four buildings were the College Library (now Powell Library); Royce Hall; the Physics-Biology Building (which became the Humanities Building and is now the Renee and David Kaplan Hall); and the Chemistry Building (now Haines Hall) arrayed around a quadrangular courtyard on the 400 acre (1.6 km^2) campus. The first undergraduate classes on the new campus were held in 1929 with 5,500 students. After lobbying by alumni; faculty; administration and community leaders UCLA was permitted to award the master’s degree in 1933 and the doctorate in 1936 against continued resistance from UC Berkeley.

    Maturity as a university

    During its first 32 years UCLA was treated as an off-site department of UC. As such its presiding officer was called a “provost” and reported to the main campus in Berkeley. In 1951 UCLA was formally elevated to co-equal status with UC Berkeley, and its presiding officer Raymond B. Allen was the first chief executive to be granted the title of chancellor. The appointment of Franklin David Murphy to the position of Chancellor in 1960 helped spark an era of tremendous growth of facilities and faculty honors. By the end of the decade UCLA had achieved distinction in a wide range of subjects. This era also secured UCLA’s position as a proper university and not simply a branch of the UC system. This change is exemplified by an incident involving Chancellor Murphy, which was described by him:

    I picked up the telephone and called in from somewhere and the phone operator said, “University of California.” And I said, “Is this Berkeley?” She said, “No.” I said, “Well who have I gotten to?” “UCLA.” I said, “Why didn’t you say UCLA?” “Oh”, she said, “we’re instructed to say University of California.” So the next morning I went to the office and wrote a memo; I said, “Will you please instruct the operators, as of noon today, when they answer the phone to say, ‘UCLA.'” And they said, “You know they won’t like it at Berkeley.” And I said, “Well, let’s just see. There are a few things maybe we can do around here without getting their permission.”

    Recent history

    On June 1, 2016 two men were killed in a murder-suicide at an engineering building in the university. School officials put the campus on lockdown as Los Angeles Police Department officers including SWAT cleared the campus.

    In 2018, a student-led community coalition known as “Westwood Forward” successfully led an effort to break UCLA and Westwood Village away from the existing Westwood Neighborhood Council and form a new North Westwood Neighborhood Council with over 2,000 out of 3,521 stakeholders voting in favor of the split. Westwood Forward’s campaign focused on making housing more affordable and encouraging nightlife in Westwood by opposing many of the restrictions on housing developments and restaurants the Westwood Neighborhood Council had promoted.

    Academics

    Divisions

    Undergraduate

    College of Letters and Science
    Social Sciences Division
    Humanities Division
    Physical Sciences Division
    Life Sciences Division
    School of the Arts and Architecture
    Henry Samueli School of Engineering and Applied Science (HSSEAS)
    Herb Alpert School of Music
    School of Theater, Film and Television
    School of Nursing
    Luskin School of Public Affairs

    Graduate

    Graduate School of Education & Information Studies (GSEIS)
    School of Law
    Anderson School of Management
    Luskin School of Public Affairs
    David Geffen School of Medicine
    School of Dentistry
    Jonathan and Karin Fielding School of Public Health
    Semel Institute for Neuroscience and Human Behavior
    School of Nursing

    Research

    UCLA is classified among “R1: Doctoral Universities – Very high research activity” and had $1.32 billion in research expenditures in FY 2018.

     
  • richardmitnick 9:26 am on February 12, 2021 Permalink | Reply
    Tags: "Shaping Light Pulses with Deep Learning", , Directly shaping arbitrary THz input pulses into a variety of desired waveforms., , Ozcan Lab, , UCLA   

    From UCLA via Optics & Photonics: “Shaping Light Pulses with Deep Learning” 

    UCLA bloc

    From UCLA

    via

    From Optics & Photonics

    11 February 2021
    William G. Schulz

    1
    Illustration of an optical diffractive network, trained with deep learning techniques, to directly shape pulses of light. Credit: Ozcan Lab/UCLA.

    Direct engineering and control of terahertz pulses could boost access to those wavelengths for many powerful applications in spectroscopy, imaging, optical communications and more. But wrangling the phase and amplitude values of a continuum of frequencies in the THz band has proved challenging.

    Now, researchers at University of California, Los Angeles, led by OSA Fellows Aydogan Ozcan and Mona Jarrahi, say they have used deep learning and a 3D printer to create a passive network device that can directly shape arbitrary THz input pulses into a variety of desired waveforms [Nature Communications]. The team writes that these results further motivate “the development of all-optical machine learning and information processing platforms that can better harness the 4D spatiotemporal information carried by light.”

    Shaping any terahertz pulse

    The team’s method, Ozcan says, can directly shape any input THz pulse through passive light diffraction via deep-learning-designed, 3D-printed polymer wafers. It is fundamentally different, he says, from previous approaches that indirectly synthesize a desired THz pulse through optical-to-terahertz converters or shaping of the optical pump that interacts with THz sources.

    What is more, Ozcan adds, the deep-learning framework is flexible and versatile; it can be used to engineer THz pulses regardless of polarization state, beam shape, beam quality or aberrations of the specific generation mechanism.

    Diffractive optical networks

    In 2018, Ozcan’s group reported development of the first all-optical diffractive deep neural network using 3D-printed polymer wafers with uneven surfaces for light diffraction. That work was primarily about machine learning by way of light propagated through the trained diffractive layers to execute an image-classification task, he says.

    But deep-learning-designed diffractive networks can also tackle inverse design problems in optics and photonics, Ozcan says, and the team’s new work in THz pulse shaping “highlights this unique opportunity.” They used diffractive optical networks—four wafers in a precisely stacked and spaced arrangement—to shape pulses by simultaneously controlling the relative phase and amplitude of each spectral component across a continuous and wide range of frequencies, the researchers write.

    On-demand synthesis of new pulses

    2
    A 3D-printed optical diffractive network that is used to engineer THz pulses. Credit: Ozcan Lab/UCLA.

    For on-demand synthesis of new pulses, Ozcan says, the team used a Lego-like physical transfer learning approach. That is, by training with deep learning a new layer or layers to replace part of an existing network model, the team found new pulses can be synthesized.

    In terms of its footprint, the pulse-shaping framework has a compact design, with an axial length of approximately 250 wavelengths, Ozcan says. Moreover, he adds, it does not use any conventional optical components such as spatial light modulators, which makes it ideal for pulse shaping in the THz band—where high-resolution spatiotemporal modulation and control of complex wavefronts over a broad bandwidth represent a significant challenge.

    Improving efficiency

    To improve the efficiency of the network, Ozcan says, a switch to low-absorption polymers for the 3D-printing material could be beneficial. To further improve output efficiency, he says, antireflective coatings over diffractive surfaces could be used to reduce back reflections.

    Altogether, the capabilities of the deep-learning-designed diffractive network approach to pulse shaping enable a variety of new opportunities, Ozcan says. When merged with appropriate fabrication methods and materials, he adds, the approach can be used to directly engineer THz pulses generated through quantum cascade lasers, solid-state circuits and particle accelerators.

    “There is already commercial interest in licensing diffractive-network–related intellectual property,” Ozcan says, “and we expect this to accelerate as we continue demonstrating some of the unique advantages of this framework for various applications in machine learning, computer vision and optical design.”

    The team is also working on visible diffractive networks, which could benefit various applications in computer vision and computational imaging fields, says Ozcan, calling it “work in progress.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Optics and Photonics News (OPN) is The Optical Society’s monthly news magazine. It provides in-depth coverage of recent developments in the field of optics and offers busy professionals the tools they need to succeed in the optics industry, as well as informative pieces on a variety of topics such as science and society, education, technology and business. OPN strives to make the various facets of this diverse field accessible to researchers, engineers, businesspeople and students. Contributors include scientists and journalists who specialize in the field of optics. We welcome your submissions.

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 5:40 pm on February 5, 2021 Permalink | Reply
    Tags: "UCLA Material Scientists Discover New Ways to Power Up Nanomaterials for Electronic Applications", , , , Perovskite materials have a crystal-lattice structure of inorganic molecules like that of ceramics along with organic molecules that are interlaced throughout., , UCLA, UCLA Samueli School of Engineering, When the organic molecules are designed properly they not only can maintain the crystal lattice structure but also contribute to the materials’ electronic properties.   

    From UCLA Samueli School of Engineering at UCLA: “UCLA Material Scientists Discover New Ways to Power Up Nanomaterials for Electronic Applications” 

    From UCLA Samueli School of Engineering

    at

    UCLA bloc

    UCLA

    Feb 4, 2021

    1
    Schematic of perovskite material with organic molecules that can add to its electronic properties.
    Credit: Jingjing Xue and Rui Wang/UCLA Samueli.

    UCLA materials scientists and colleagues have discovered that perovskites, a class of promising materials that could be used for low-cost, high-performance solar cells and LEDs, have a previously unutilized molecular component that can further tune the electronic property of perovskites.

    Named after Russian mineralogist Lev Perovski, perovskite materials have a crystal-lattice structure of inorganic molecules like that of ceramics, along with organic molecules that are interlaced throughout. Up to now, these organic molecules appeared to only serve a structural function and could not directly contribute to perovskites’ electronic performance.

    Led by UCLA, a new study shows that when the organic molecules are designed properly, they not only can maintain the crystal lattice structure, but also contribute to the materials’ electronic properties. This discovery opens up new possibilities to improve the design of materials that will lead to better solar cells and LEDs. The study detailing the research was recently published in Science.

    “This is like finding an old dog that can play new tricks,” said Yang Yang, the Carol and Lawrence E. Tannas Jr. Professor of Engineering at the UCLA Samueli School of Engineering, who is the principal investigator on the research. “In materials science, we look all the way down to the atomic structure of a material for efficient performance. Our postdocs and graduate students didn’t take anything for granted and dug deeper to find a new pathway.”

    On its exterior, the positively charged ammonium molecule connected to molecules of pyrene — a quadruple ring of carbon atoms. This molecular design offered additional electronic tunability of perovskites.

    “The unique property of perovskites is that they have the advantage of high-performance inorganic semiconductors, as well as easy and low-cost processability of polymers,” said study co-lead author Rui Wang, a UCLA postdoctoral scholar in materials science and engineering. “This newly enhanced perovskite material now offers opportunities for improved design concepts with better efficiency.”

    To demonstrate perovskites’ added effectiveness, the team built a photovoltaic (PV) cell prototype with the materials, and then tested it under continuous light for 2,000 hours. The new cell continued to convert light to energy at 85% of its original efficiency. This contrasts with a PV cell made of the same materials, but without the added altered organic molecule, which retained only 60% of its original efficiency.

    The other co-lead authors on the study are Jingjing Xue, a materials science postdoctoral scholar at UCLA; and Xihan Chen of the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) in Colorado. The other corresponding authors include Matthew Beard, a senior research fellow at NREL and the director of its Center for Hybrid Organic Inorganic Semiconductors for Energy; and Yanfa Yan, a professor of physics and astronomy at the University of Toledo.

    Other authors are from UCLA; NREL; the University of Toledo; Yangzhou University (CN); Soochow University (CN); Monash University (AU) and Lawrence Berkeley National Laboratory (US).

    The research was funded in part by the U.S. Department of Energy.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    The UCLA Henry Samueli School of Engineering and Applied Science (HSSEAS), informally known as UCLA Engineering, is the school of engineering at the University of California, Los Angeles (UCLA). It opened as the College of Engineering in 1945, and was renamed the School of Engineering in 1969.[2] Since its initial enrollment of 379 students, the school has grown to approximately 6,100 students. The school is ranked 16th among all engineering schools in the United States.[3] The school offers 28 degree programs and is home to eight externally funded interdisciplinary research centers, including those in space exploration, wireless sensor systems, and nanotechnology.

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 5:19 pm on February 2, 2021 Permalink | Reply
    Tags: "Researchers create novel photonic chip", A photonic digital to analog converter without leaving the optical domain, A schematic representation of the impact and potential uses of a photonic DAC in a 5 G network., Current optical networks through which most of the world's data is transmitted as well as many sensors require a digital-to-analog conversion., , Performance results of the coherent parallel PBW DAC 4‐bit prototype., , Schematic diagram of a 4‐bit PBW DAC based on unbalanced directional couplers and modulators., Schematic representation of three different implementations of optical DACs namely serial; incoherent; and coherent parallel., Such novel converters can advance next-generation data processing hardware with high relevance for data centers; 6G networks; artificial intelligence; and more., UCLA, Volker J. Sorger associate professor of electrical and computer engineering at GW and his colleagues have created a digital-to-analog converter that does not require the signal to be converted.   

    From George Washington University and From UCLA via phys.org: “Researchers create novel photonic chip” 

    From George Washington University

    and

    UCLA bloc

    From UCLA

    via


    phys.org

    February 2, 2021

    1
    Credit: CC0 Public Domain.

    Researchers at the George Washington University and University of California, Los Angeles, have developed and demonstrated for the first time a photonic digital to analog converter without leaving the optical domain. Such novel converters can advance next-generation data processing hardware with high relevance for data centers, 6G networks, artificial intelligence and more.

    1
    A schematic representation of the impact and potential uses of a photonic DAC in a 5 G network. The photonic DAC would be used at the interface between the electronic and photonic platforms both in the information “fog” and in the “cloud” layers, such as in optical information processing, intelligent routing, and label‐date processing or sensor preprocessing at the edge of the network and within servers in the cloud.

    2
    Schematic representation of three different implementations of optical DACs, namely serial, incoherent, and coherent parallel. a) The serial scheme is based on summation of weighted multiwavelength pulses opportunely spaced in time by properly setting the wavelength spacing and the length of dispersive medium. b) The parallel implementation is based on the weighted integration of multiple wavelengths which encode a bit sequence. c) Coherent parallel optical DAC (PBW DAC), in this work, uses preset unbalanced directional couplers that fan out the optical carrier unevenly into different channels, which are then individually modulated at high speeds using electro–optic modulators (or alternatively 2 × 2 switches). The predetermined phase shift (in case of the represented binary “0” or “1”) is actively compensated with phase shifters ( 𝛥𝜙) toward a coherent summation using passive waveguide combiners. This enables keeping the signal in the optical domain (O–E–O conversion is not required) for synergistic use in optical machine learning[18-20] or optical telecommunication systems.

    3
    Schematic diagram of a 4‐bit PBW DAC based on unbalanced directional couplers and modulators. a) Schematic of the working principle. b) Sketch of a PBW DAC in parallel configuration. A carrier (CW laser) is fanned out into multiple branches via an unbalanced directional coupler (i. Scanning electron microscope [SEM] image of the directional couplers and its operation) according to the formula: (1−r)N where r is the splitting ratio (r = 0.75) and N is the number of bits. The intensity of the signal is modulated in each branch by an EAM (extinction ratio = 4.6 dB) according to a digital input electrical signal. In the presence of a binary “0,” a systematic phase shift is added to the branch compensating for the optical pathlength variation after modulation. This then allows for the optical signals to be (passively) coherently summed by means of a combiner (ii. SEM image of the combiner and device principle). c) Microscope image of the fabricated passive 4‐bit PBW DAC circuit with the integration of thermal phase shifters for the digital input “1111.” d) Optical measurements of the passive 4‐bit PBW DAC. The output for each digital input configuration is collected using an IR camera, ultimate with high‐speed integrated detectors. The layout of the PIC (red) is superimposed to the IR image for clarity. The optical power for the digital input “1111” state is shown.

    4
    Performance results of the coherent parallel PBW DAC 4‐bit prototype. a) Analog optical signal output power. Comparison between the experimental PIC results obtained for all 2N  = 16 DAC output states (blue square), the photonic circuit simulated version (green triangle) and the theoretical prediction according to the formula (red circle). The quadratic function is expected (Equation (2)) as the optical intensity (I) scales with the square of the electric field (E), i.e., I∼|E2|. b) Eye diagram of a 4‐bit DAC assuming thermal noise of the photodetector, static (1 ps) and random jitter (1 ps) of the pseudorandom bit sequence used as digital input to the modulators. c) DAC quality performance: DNL and d) INL for the given electrical digital signal inputs of the measured analog outputs corresponding to an increment of 1 LSB with respect to the best fit regression. The DNL is between −0.94 and 0.71 LSB whereas the INL is smaller than 1.99 LSB.

    Current optical networks, through which most of the world’s data is transmitted, as well as many sensors, require a digital-to-analog conversion, which links digital systems synergistically to analog components.

    Using a silicon photonic chip platform, Volker J. Sorger, an associate professor of electrical and computer engineering at GW, and his colleagues have created a digital-to-analog converter that does not require the signal to be converted in the electrical domain, thus showing the potential to satisfy the demand for high data-processing capabilities while acting on optical data, interfacing to digital systems, and performing in a compact footprint, with both short signal delay and low power consumption.

    “We found a way to seamlessly bridge the gap that exists between these two worlds, analog and digital,” Sorger said. “This device is a key stepping stone for next-generation data processing hardware.”

    Electronic Bottleneck Suppression in Next-Generation Networks with Integrated Photonic Digital-to-Analog Converters, is published in Advanced Photonics Research.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

    The George Washington University (GW or GWU) is a private research university in Washington, D.C. It was chartered in 1821 by an act of the United States Congress.

    The university is organized into 14 colleges and schools, including the Columbian College of Arts and Sciences, the Elliott School of International Affairs, the GW School of Business, the School of Media and Public Affairs, the Trachtenberg School of Public Policy and Public Administration, the GW Law School and the Corcoran School of the Arts and Design. George Washington’s main Foggy Bottom Campus is located in the heart of Washington, D.C., with the International Monetary Fund and the World Bank located on campus and the White House and the U.S. Department of State within blocks of campus. GWU hosts numerous research centers and institutes, including the National Security Archive and the Institute for International Economic Policy. GWU has two satellite campuses: the Mount Vernon Campus, located in D.C.’s Foxhall neighborhood and the Virginia Science and Technology Campus. It is the largest institution of higher education in the District of Columbia.

    George Washington, the first President of the United States, advocated the establishment of a national university in the U.S. capital in his first State of the Union address in 1790 and continued to promote this idea throughout his career and until his death. In his will, Washington left shares in the Potomac Company to endow the university. However, due to the company’s financial difficulties, funds were raised independently.[9] On February 9, 1821, the university was founded by an Act of Congress, making it one of only five universities in the United States with a Congressional charter.

    George Washington offers degree programs in seventy-one disciplines, enrolling an average of 11,000 undergraduate and 15,500 post-graduate students from more than 130 countries. The Princeton Review ranked GWU 1st for “Top Colleges or Universities for Internship Opportunities. As of 2015, George Washington had over 1,100 active alumni in the U.S. Foreign Service, one of the largest feeder schools for the diplomatic corps. GWU is consistently ranked by The Princeton Review in the top “Most Politically Active” Schools.

    George Washington is home to extensive student life programs, a strong Greek culture, and over 450 other student organizations. The school’s athletic teams, the George Washington Colonials, play in the Atlantic 10 Conference. GW is known for the numerous prominent events it holds yearly, from hosting U.S. presidential debates and academic symposiums to the being the host of the World Bank and International Monetary Fund’s Annual Meetings in DC, since 2013.

    George Washington alumni, faculty and affiliates include numerous prominent politicians, including 16 heads of state or government, current U.S. Cabinet members, Fortune 500 CEOs, Nobel laureates, MacArthur fellows, Olympic athletes, Academy Award and Golden Globe winners, royalty, and Time 100 notables.

     
  • richardmitnick 1:45 pm on November 29, 2020 Permalink | Reply
    Tags: "Our Solar System Is Going to Totally Disintegrate Sooner Than We Thought", , , , , , , UCLA,   

    From University of Michigan, Caltech and UCLA via Science Alert (AU):”Our Solar System Is Going to Totally Disintegrate Sooner Than We Thought” 

    U Michigan bloc

    From University of Michigan

    and

    Caltech Logo

    Caltech

    and

    UCLA bloc

    UCLA

    via

    ScienceAlert

    Science Alert (AU)

    29 NOVEMBER 2020
    MICHELLE STARR

    Milky Way Credits: NASA/JPL-Caltech /ESO R. Hurt. The bar is visible in this image.

    1
    A white dwarf star after ejecting its mass to form a planetary nebula. Credit: ESO/P. Weilbacher/AIP.

    Although the ground beneath our feet feels solid and reassuring (most of the time), nothing in this Universe lasts forever.

    One day, our Sun will die, ejecting a large proportion of its mass before its core shrinks down into a white dwarf, gradually leaking heat until it’s nothing more than a cold, dark, dead lump of rock, a thousand trillion years later.

    But the rest of the Solar System will be long gone by then. According to new simulations, it will take just 100 billion years for any remaining planets to skedaddle off across the galaxy, leaving the dying Sun far behind.

    Astronomers and physicists have been trying to puzzle out the ultimate fate of the Solar System for at least hundreds of years.

    “Understanding the long-term dynamical stability of the solar system constitutes one of the oldest pursuits of astrophysics, tracing back to Newton himself, who speculated that mutual interactions between planets would eventually drive the system unstable,” wrote astronomers Jon Zink of the University of California, Los Angeles, Konstantin Batygin of Caltech and Fred Adams of the University of Michigan in The Astronomical Journal.

    But that’s a lot trickier than it might seem. The greater the number of bodies that are involved in a dynamical system, interacting with each other, the more complicated that system grows and the harder it is to predict. This is called the N-body problem.

    Because of this complexity, it’s impossible to make deterministic predictions of the orbits of Solar System objects past certain timescales. Beyond about five to 10 million years, certainty flies right out the window.

    But, if we can figure out what’s going to happen to our Solar System, that will tell us something about how the Universe might evolve, on timescales far longer than its current age of 13.8 billion years.

    In 1999, astronomers predicted [Science] that the Solar System would slowly fall apart over a period of at least a billion billion – that’s 10^18, or a quintillion – years. That’s how long it would take, they calculated, for orbital resonances from Jupiter and Saturn to decouple Uranus.

    According to Zink’s team, though, this calculation left out some important influences that could disrupt the Solar System sooner.

    Firstly, there’s the Sun.

    In about 5 billion years, as it dies, the Sun will swell up into a red giant, engulfing Mercury, Venus and Earth. Then it will eject nearly half its mass, blown away into space on stellar winds; the remaining white dwarf will be around just 54 percent of the current solar mass.

    This mass loss will loosen the Sun’s gravitational grip on the remaining planets, Mars and the outer gas and ice giants, Jupiter, Saturn, Uranus, and Neptune.

    Secondly, as the Solar System orbits the galactic centre, other stars ought to come close enough to perturb the planets’ orbits, around once every 23 million years.

    “By accounting for stellar mass loss and the inflation of the outer planet orbits, these encounters will become more influential,” the researchers wrote.

    “Given enough time, some of these flybys will come close enough to disassociate – or destabilise – the remaining planets.”

    With these additional influences accounted for in their calculations, the team ran 10 N-body simulations for the outer planets (leaving out Mars to save on computation costs, since its influence should be negligible), using the powerful Shared Hoffman2 Cluster.

    3
    Hoffman2 Cluster. Credit: UCLA.

    These simulations were split into two phases: up to the end of the Sun’s mass loss, and the phase that comes after.

    Although 10 simulations isn’t a strong statistical sample, the team found that a similar scenario played out each time.

    After the Sun completes its evolution into a white dwarf, the outer planets have a larger orbit, but still remain relatively stable. Jupiter and Saturn, however, become captured in a stable 5:2 resonance – for every five times Jupiter orbits the Sun, Saturn orbits twice (that eventual resonance has been proposed many times, not least by Isaac Newton himself).

    These expanded orbits, as well as characteristics of the planetary resonance, makes the system more susceptible to perturbations by passing stars.

    After 30 billion years, such stellar perturbations jangle those stable orbits into chaotic ones, resulting in rapid planet loss. All but one planet escape their orbits, fleeing off into the galaxy as rogue planets.

    That last, lonely planet sticks around for another 50 billion years, but its fate is sealed. Eventually, it, too, is knocked loose by the gravitational influence of passing stars. Ultimately, by 100 billion years after the Sun turns into a white dwarf, the Solar System is no more.

    That’s a significantly shorter timeframe than that proposed in 1999. And, the researchers carefully note, it’s contingent on current observations of the local galactic environment, and stellar flyby estimates, both of which may change. So it’s by no means engraved in stone.

    Even if estimates of the timeline of the Solar System’s demise do change, however, it’s still many billions of years away. The likelihood of humanity surviving long enough to see it is slim.

    Sleep tight!

    See the full article here .


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

    Please support STEM education in your local school system

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

    U MIchigan Campus

    The University of Michigan (U-M, UM, UMich, or U of M), frequently referred to simply as Michigan, is a public research university located in Ann Arbor, Michigan, United States. Originally, founded in 1817 in Detroit as the Catholepistemiad, or University of Michigania, 20 years before the Michigan Territory officially became a state, the University of Michigan is the state’s oldest university. The university moved to Ann Arbor in 1837 onto 40 acres (16 ha) of what is now known as Central Campus. Since its establishment in Ann Arbor, the university campus has expanded to include more than 584 major buildings with a combined area of more than 34 million gross square feet (781 acres or 3.16 km²), and has two satellite campuses located in Flint and Dearborn. The University was one of the founding members of the Association of American Universities.

    Considered one of the foremost research universities in the United States,[7] the university has very high research activity and its comprehensive graduate program offers doctoral degrees in the humanities, social sciences, and STEM fields (Science, Technology, Engineering and Mathematics) as well as professional degrees in business, medicine, law, pharmacy, nursing, social work and dentistry. Michigan’s body of living alumni (as of 2012) comprises more than 500,000. Besides academic life, Michigan’s athletic teams compete in Division I of the NCAA and are collectively known as the Wolverines. They are members of the Big Ten Conference.

     
  • richardmitnick 8:30 am on July 10, 2020 Permalink | Reply
    Tags: , , Coral Triangle in the Pacific which has one of the highest levels of biodiversity in the world including 600 different coral species., Formation of new and distinct marine species through host-shifting may occur among other marine organisms as well., , Marine snails, Mollusks called nudibranchs, The Coral Triangle spans roughly 6.3 million square miles, UCLA   

    From UCLA: “Discovery opens up new path in study of marine evolution and biodiversity” 

    UCLA bloc

    From UCLA

    July 8, 2020

    Media Contact
    David Colgan
    818-203-2858
    dcolgan@ioes.ucla.edu

    Written by Kaitlyn DeShon

    1
    A coral reef off of the island of Komodo, Indonesia. Sara Simmonds/UCLA.

    New UCLA research indicates that an evolutionary phenomenon never before observed among marine life could help explain why there is such immense biodiversity in the world’s coral reefs and the ocean beyond.

    Two studies — one of reef-dwelling marine snails [Ecology and Evolution], the other of similar mollusks called nudibranchs [Molecular Phylogenetics and Evolution] — show for the first time that new species of both groups may be emerging as a result of host-switching, in which populations of these animals that rely on a single species of coral for food and habitat switch to a new coral species, leading to wide genetic and physical differentiation. The phenomenon had only been seen previously in viruses, insects and several other organisms.

    “This is the first time that anyone has seen this, but no one has ever looked,” said UCLA professor of ecology and evolutionary biology Paul Barber, whose lab conducted both studies. “This very well could be the tip of the iceberg.”

    The findings suggest the possibility that the formation of new and distinct marine species through host-shifting may occur among other marine organisms as well, Barber said, opening up new avenues for research into the causes of marine biodiversity.

    On land, new species are typically thought to evolve when natural barriers like mountains, canyons or rivers separate individuals or groups from one another. The ocean, however, has different barriers, including reef structures and currents, both of which contribute to host-shifting among snails and nudibranchs, the researchers note.

    The larvae of snails and nudibranchs that subsist on a single species of coral will at times be swept away by ocean currents; if they aren’t lost or eaten, they can land on an entirely different coral species, where they imprint and spend their whole lives. Eventually, the scientists say, a generational line of snails or nudibranchs will evolve to prefer that particular coral and form a new species.

    “It’s pretty likely that the corals are helping the nudibranchs form new species, in a way,” said Allison Fritts-Penniman, lead author of the nudibranch study, which reported a three-fold increase in known species for this group. “The more corals they can live on, the more different nudibranch species can evolve.”

    The two new papers may mark the beginning of marine speciation discoveries — for nudibranchs and snails, which are common but understudied, as well as more broadly, said Sara Simmonds, lead author of the snail study, which used genomics to catch speciation in the act.

    “Finding that divergence and speciation can happen in the oceans even with gene flow is an important discovery, not just for the marine environment but also for understanding evolution and speciation in general,” Simmonds said.

    Both studies focused on a relatively small area of the western Pacific Ocean known at the Coral Triangle, which has one of the highest levels of biodiversity in the world, including 600 different coral species.

    “If there are so many corals, and so many of them have these strong associations, this very well could be an incredibly important process in generating all of this diversity,” said Barber, who also stressed the importance of protecting reef systems like the Coral Triangle from the devastating effects of climate change and industry-related threats.

    Preserving the Coral Triangle

    The Coral Triangle spans roughly 6.3 million square miles, accounting for about 1.6% of the world’s oceans, and is bordered by several countries, including Indonesia, the Philippines and Papua New Guinea. With hundreds of coral species and thousands of species of fish and other marine organisms, it is, Barber says, one of the most biodiverse, least studied and most threatened locations in the world.

    While coastal development, unsustainable tourism and habitat destruction through “bomb fishing” with homemade explosives all pose significant dangers to the region, the biggest threat is climate change, which is damaging the reefs that underpin the Triangle’s biodiverse ecosystem. Ocean warming, acidification and rising sea levels are causing mass coral bleaching, in which coral expel living algae from their tissues and turn completely white; this can lead to coral death if the stressful conditions continue for too long. The World Wildlife Fund predicts that at the current rate of climate change, the Coral Triangle will disappear by 2100.

    Major climate change–induced damage to the region’s biodiversity also puts the economies of the surrounding countries at risk, Barber notes, and a collapse of the marine ecosystem would result in the destruction of the region’s vast fishing industry and subsequent food insecurity for hundreds of millions of people.

    Continuing to carry out research to boost our understanding what generates biodiversity in the Coral Triangle and other reefs is one of the major keys to protecting them in the fight against climate change, Barber said.

    Even the public is getting involved in furthering that understanding, with citizen snorkelers and divers all over the world contributing to an effort by the nonprofit iNaturalist, a joint initiative of the California Academy of Sciences and the National Geographic Society, to search for new coral-associated nudibranch species and helping scientists with the fieldwork needed for further study.

    “The Coral Triangle is the world’s largest, most biodiverse marine ecosystem,” said Barber. “There is still so much to learn from it.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 12:39 pm on May 18, 2020 Permalink | Reply
    Tags: "UCLA physicists develop world’s best quantum bits", , , UCLA   

    From UCLA: “UCLA physicists develop world’s best quantum bits” 

    UCLA bloc

    From UCLA

    1
    Assistant Professor Wesley Campbell, UCLA Physics & Astronomy (Photo Credit: UCLA)

    A team of researchers at UCLA has set a new record for preparing and measuring the quantum bits, or qubits, inside of a quantum computer without error. The techniques they have developed make it easier to build quantum computers that outperform classical computers for important tasks, including the design of new materials and pharmaceuticals. The research is published in the peer-reviewed, online open-access journal, npj Quantum Information, published by Nature and including the exceptional research on quantum information and quantum computing.

    Currently, the most powerful quantum computers are “noisy intermediate-scale quantum” (NISQ) devices and are very sensitive to errors. Error in preparation and measurement of qubits is particularly onerous: for 100 qubits, a 1% measurement error means a NISQ device will produce an incorrect answer about 63% of the time, said senior author Eric Hudson, a UCLA professor of physics and astronomy.

    To address this major challenge, Hudson and UCLA colleagues recently developed a new qubit hosted in a laser-cooled, radioactive barium ion. This “goldilocks ion” has nearly ideal properties for realizing ultra-low error rate quantum devices, allowing the UCLA group to achieve a preparation and measurement error rate of about 0.03%, lower than any other quantum technology to date, said co-senior author Wesley Campbell, also a UCLA professor of physics and astronomy.

    The development of this exciting new qubit at UCLA should impact almost every area of quantum information science, Hudson said. This radioactive ion has been identified as a promising system in quantum networking, sensing, timing, simulation and computation, and the researchers’ paper paves the way for large-scale NISQ devices.

    Co-authors are lead author Justin Christensen, a postdoctoral scholar in Hudson’s laboratory, and David Hucul, a former postdoctoral scholar in Hudson and Campbell’s laboratories, who is now a physicist at the U.S. Air Force Research Laboratory.

    The research is funded by the U.S. Army Research Office.

    Campbell and Hudson are primary investigators of a major $2.7 million U.S. Department of Energy Quantum Information Science Research project to lay the foundation for the next generation of computing and information processing, as well as many other innovative technologies.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 11:52 am on March 10, 2020 Permalink | Reply
    Tags: "UCLA-led research team produces most accurate 3D images of ‘2D materials’", , , , , , The researchers examined a single layer of molybdenum disulfide a frequently studied 2D material., UCLA   

    From UCLA Newsroom: “UCLA-led research team produces most accurate 3D images of ‘2D materials’” 


    From UCLA Newsroom

    March 9, 2020
    Wayne Lewis

    1
    Image showing the 3D atomic coordinates of molybdenum (blue), sulfur (yellow) and added rhenium (orange). A 2D image is shown beneath the 3D model.

    Scientists develop innovative technique to pinpoint coordinates of single atoms.

    A UCLA-led research team has produced in unprecedented detail experimental three-dimensional maps of the atoms in a so-called 2D material — matter that isn’t truly two-dimensional but is nearly flat because it’s arranged in extremely thin layers, no more than a few atoms thick.

    Although 2D-materials–based technologies have not yet been widely used in commercial applications, the materials have been the subject of considerable research interest. In the future, they could be the basis for semiconductors in ever smaller electronics, quantum computer components, more-efficient batteries, or filters capable of extracting freshwater from saltwater.

    The promise of 2D materials comes from certain properties that differ from how the same elements or compounds behave when they appear in greater quantities. Those unique characteristics are influenced by quantum effects — phenomena occurring at extremely small scales that are fundamentally different from the classical physics seen at larger scales. For instance, when carbon is arranged in an atomically thin layer to form 2D graphene, it is stronger than steel, conducts heat better than any other known material, and has almost zero electrical resistance.

    But using 2D materials in real-world applications would require a greater understanding of their properties, and the ability to control those properties. The new study, which was published in Nature Materials, could be a step forward in that effort.

    The researchers showed that their 3D maps of the material’s atomic structure are precise to the picometer scale — measured in one-trillionths of a meter. They used their measurements to quantify defects in the 2D material, which can affect their electronic properties, as well as to accurately assess those electronic properties.

    “What’s unique about this research is that we determine the coordinates of individual atoms in three dimensions without using any pre-existing models,” said corresponding author Jianwei “John” Miao, a UCLA professor of physics and astronomy. “And our method can be used for all kinds of 2D materials.”

    Miao is the deputy director of the STROBE National Science Foundation Science and Technology Center and a member of the California NanoSystems Institute at UCLA. His UCLA lab collaborated on the study with researchers from Harvard University, Oak Ridge National Laboratory and Rice University.

    The researchers examined a single layer of molybdenum disulfide, a frequently studied 2D material. In bulk, this compound is used as a lubricant. As a 2D material, it has electronic properties that suggest it could be employed in next-generation semiconductor electronics. The samples being studied were “doped” with traces of rhenium, a metal that adds spare electrons when replacing molybdenum. That kind of doping is often used to produce components for computers and electronics because it helps facilitate the flow of electrons in semiconductor devices.

    To analyze the 2D material, the researchers used a new technology they developed based on scanning transmission electron microscopy, which produces images by measuring scattered electrons beamed through thin samples. Miao’s team devised a technique called scanning atomic electron tomography, which produces 3D images by capturing a sample at multiple angles as it rotates.

    The scientists had to avoid one major challenge to produce the images: 2D materials can be damaged by too much exposure to electrons. So for each sample, the researchers reconstructed images section by section and then stitched them together to form a single 3D image — allowing them to use fewer scans and thus a lower dose of electrons than if they had imaged the entire sample at once.

    The two samples each measured 6 nanometers by 6 nanometers, and each of the smaller sections measured about 1 nanometer by 1 nanometer. (A nanometer is one-billionth of a meter.)

    The resulting images enabled the researchers to inspect the samples’ 3D structure to a precision of 4 picometers in the case of molybdenum atoms — 26 times smaller than the diameter of a hydrogen atom. That level of precision enabled them to measure ripples, strain distorting the shape of the material, and variations in the size of chemical bonds, all changes caused by the added rhenium — marking the most accurate measurement ever of those characteristics in a 2D material.

    “If we just assume that introducing the dopant is a simple substitution, we wouldn’t expect large strains,” said Xuezeng Tian, the paper’s co-first author and a UCLA postdoctoral scholar. “But what we have observed is more complicated than previous experiments have shown.”

    The scientists found that the largest changes occurred in the smallest dimension of the 2D material, its three-atom-tall height. It took as little as a single rhenium atom to introduce such local distortion.

    Armed with information about the material’s 3D coordinates, scientists at Harvard led by Professor Prineha Narang performed quantum mechanical calculations of the material’s electronic properties.

    “These atomic-scale experiments have given us a new lens into how 2D materials behave and how they should be treated in calculations, and they could be a game changer for new quantum technologies,” Narang said.

    Without access to the sort of measurements generated in the study, such quantum mechanical calculations conventionally have been based on a theoretical model system that is expected at a temperature of absolute zero.

    The study indicated that the measured 3D coordinates led to more accurate calculations of the 2D material’s electronic properties.

    “Our work could transform quantum mechanical calculations by using experimental 3D atomic coordinates as direct input,” said UCLA postdoctoral scholar Dennis Kim, a co-first author of the study. “This approach should enable material engineers to better predict and discover new physical, chemical and electronic properties of 2D materials at the single-atom level.”

    Other authors were Yongsoo Yang, Yao Yang and Yakun Yuan of UCLA; Shize Yang and Juan-Carlos Idrobo of Oak Ridge National Laboratory; Christopher Ciccarino and Blake Duschatko of Harvard; and Yongji Gong and Pulickel Ajayan of Rice.

    The research was supported by the U.S. Department of Energy, the U.S. Army Research Office, and STROBE National Science Foundation Science and Technology Center. The scanning transmission electron microscopy experiments were conducted at the Center for Nanophase Materials Sciences, a DOE user facility at Oak Ridge National Laboratory.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 10:31 am on December 15, 2019 Permalink | Reply
    Tags: "A second black hole at our galaxy’s center?", , , , , , , , , , UCLA   

    From UCLA via EarthSky: “A second black hole at our galaxy’s center?” 

    UCLA bloc

    From UCLA

    via

    1

    EarthSky

    December 15, 2019
    Smadar Naoz, University of California, Los Angeles

    1
    Artist’s concept of 2 black holes entwined in a gravitational tango. Image via NASA/ JPL-Caltech/ SwRI/ MSSS/ Christopher Go.

    There’s a supermassive black hole – 4 million times our sun’s mass – in the center of our Milky Way galaxy. Astronomers who’ve measured star movements near this central black hole are now saying there might be a 2nd companion black hole near it.

    Do supermassive black holes have friends? The nature of galaxy formation suggests that the answer is yes, and in fact, pairs of supermassive black holes should be common in the universe.

    I am an astrophysicist and am interested in a wide range of theoretical problems in astrophysics, from the formation of the very first galaxies to the gravitational interactions of black holes, stars and even planets. Black holes are intriguing systems, and supermassive black holes and the dense stellar environments that surround them represent one of the most extreme places in our universe.

    The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our sun.

    SgrA* NASA/Chandra supermassive black hole at the center of the Milky Way, X-ray image of the center of our galaxy, where the supermassive black hole Sagittarius A* resides. Image via X-ray: NASA/UMass/D.Wang et al., IR: NASA/STScI.

    SGR A* , the supermassive black hole at the center of the Milky Way. NASA’s Chandra X-Ray Observatory

    A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars. Precise measurements of the orbits of these stars allowed astronomers to confirm the existence of this supermassive black hole and to measure its mass. For more than 20 years, scientists have been monitoring the orbits of these stars around the supermassive black hole. Based on what we’ve seen, my colleagues and I show that if there is a friend there, it might be a second black hole nearby that is at least 100,000 times the mass of the sun.

    Supermassive black holes and their friends

    Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the sun.

    Milky Way NASA/JPL-Caltech /ESO R. Hurt. The bar is visible in this image

    Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole. One popular idea connects to the possibility that supermassive holes have friends.

    To understand this idea, we need to go back to when the universe was about 100 million years old, to the era of the very first galaxies. They were much smaller than today’s galaxies, about 10,000 or more times less massive than the Milky Way. Within these early galaxies the very first stars that died created black holes, of about tens to thousand the mass of the sun. These black holes sank to the center of gravity, the heart of their host galaxy. Since galaxies evolve by merging and colliding with one another, collisions between galaxies will result in supermassive black hole pairs – the key part of this story.

    Milkdromeda -Andromeda on the left-Earth’s night sky in 3.75 billion years-NASA

    The black holes then collide and grow in size as well. A black hole that is more than a million times the mass of our sun is considered supermassive.

    If indeed the supermassive black hole has a friend revolving around it in close orbit, the center of the galaxy is locked in a complex dance. The partners’ gravitational tugs will also exert its own pull on the nearby stars disturbing their orbits. The two supermassive black holes are orbiting each other, and at the same time, each is exerting its own pull on the stars around it.

    The gravitational forces from the black holes pull on these stars and make them change their orbit; in other words, after one revolution around the supermassive black hole pair, a star will not go exactly back to the point at which it began.

    Using our understanding of the gravitational interaction between the possible supermassive black hole pair and the surrounding stars, astronomers can predict what will happen to stars. Astrophysicists like my colleagues and me can compare our predictions to observations, and then can determine the possible orbits of stars and figure out whether the supermassive black hole has a companion that is exerting gravitational influence.

    Using a well-studied star, called S0-2, which orbits the supermassive black hole that lies at the center of the galaxy every 16 years, we can already rule out the idea that there is a second supermassive black hole with mass above 100,000 times the mass of the sun and farther than about 200 times the distance between the sun and the Earth.

    Star S0-2 Andrea Ghez Keck/UCLA Galactic Center Group at SGR A*, the supermassive black hole at the center of the milky way

    If there was such a companion, then I and my colleagues would have detected its effects on the orbit of SO-2.

    But that doesn’t mean that a smaller companion black hole cannot still hide there. Such an object may not alter the orbit of SO-2 in a way we can easily measure.

    The physics of supermassive black holes

    Supermassive black holes have gotten a lot of attention lately. In particular, the recent image of such a giant at the center of the galaxy Messier 87 opened a new window to understanding the physics behind black holes.

    The first image of a black hole.This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    The proximity of the Milky Way’s galactic center – a mere 24,000 light-years away – provides a unique laboratory for addressing issues in the fundamental physics of supermassive black holes. For example, astrophysicists like myself would like to understand their impact on the central regions of galaxies and their role in galaxy formation and evolution. The detection of a pair of supermassive black holes in the galactic center would indicate that the Milky Way merged with another, possibly small, galaxy at some time in the past.

    That’s not all that monitoring the surrounding stars can tell us. Measurements of the star S0-2 allowed scientists to carry out a unique test of Einstein’s general theory of relativity. In May 2018, S0-2 zoomed past the supermassive black hole at a distance of only about 130 times the Earth’s distance from the sun. According to Einstein’s theory, the wavelength of light emitted by the star should stretch as it climbs from the deep gravitational well of the supermassive black hole.

    The stretching wavelength that Einstein predicted – which makes the star appear redder – was detected and proves that the theory of general relativity accurately describes the physics in this extreme gravitational zone. I am eagerly awaiting the second closest approach of S0-2, which will occur in about 16 years, because astrophysicists like myself will be able to test more of Einstein’s predictions about general relativity, including the change of the orientation of the stars’ elongated orbit. But if the supermassive black hole has a partner, this could alter the expected result.

    3
    This NASA/ESA Hubble Space Telescope image show’s the result of a galactic collision between two good-sized galaxies. This new jumble of stars is slowly evolving to become a giant elliptical galaxy. Image via ESA/ Hubble/ NASA/ Judy Schmidt

    NASA/ESA Hubble Telescope

    Finally, if there are two massive black holes orbiting each other at the galactic center, as my team suggests is possible, they will emit gravitational waves.

    Gravitational waves. Credit: MPI for Gravitational Physics/Werner Benger

    Since 2015, the LIGO-Virgo observatories have been detecting gravitational wave radiation from merging stellar-mass black holes and neutron stars.

    MIT /Caltech Advanced aLigo


    VIRGO Gravitational Wave interferometer, near Pisa, Italy

    These groundbreaking detections have opened a new way for scientists to sense the universe.

    Any waves emitted by our hypothetical black hole pair will be at low frequencies, too low for the LIGO-Virgo detectors to sense. But a planned space-based detector known as LISA may be able to detect these waves, which will help astrophysicists figure out whether our galactic center black hole is alone or has a partner.

    ESA/NASA eLISA


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

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
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