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  • richardmitnick 9:35 am on August 17, 2021 Permalink | Reply
    Tags: , "Vera Rubin’s work on dark matter led to a paradigm shift in cosmology", , , , , Fritz Zwicky and Vera Rubin,   

    From “Science News (US) : “Vera Rubin’s work on dark matter led to a paradigm shift in cosmology” 

    From “Science News (US)

    8.17.21
    Maria Temming

    1
    Bright Galaxies, Dark Matter, and Beyond
    Ashley Jean Yeager
    MIT Press, $24.95

    Vera Rubin’s research forced cosmologists to radically reimagine the cosmos.

    In the 1960s and ’70s, Rubin’s observations of stars whirling around within galaxies revealed the gravitational tug of invisible “dark matter.” Although astronomers had detected hints of this enigmatic substance for decades, Rubin’s data helped finally convince a skeptical scientific community that dark matter exists (SN: 1/10/20).

    “Her work was pivotal to redefining the composition of our cosmos,” Ashley Yeager, Science News’ associate news editor, writes in her new book. Bright Galaxies, Dark Matter, and Beyond follows Rubin’s journey from stargazing child to preeminent astronomer and fierce advocate for women in science.

    That journey, Yeager shows, was rife with obstacles. When Rubin was a young astronomer in the 1950s and ’60s, many observatories were closed to women, and more established scientists often brushed her off. Much of her early work was met with intense skepticism, but that only made Rubin, who died in 2016 at age 88, a more dogged data collector.

    On graphs plotting the speeds of stars swirling around galaxies, Rubin showed that stars farther from galactic centers orbited just as fast as inner stars. That is, the galaxies’ rotation curves were flat. Such speedy outer stars must be pulled along by the gravitational grip of dark matter.

    Science News staff writer Maria Temming spoke with Yeager about Rubin’s legacy and what, beyond her pioneering research, made Rubin remarkable. The following discussion has been edited for clarity and brevity.

    Temming: What inspired you to tell Rubin’s story?

    Yeager: It all started when I was working at the National Air and Space Museum in Washington, D.C., in 2007. I was walking around the “Explore the Universe” exhibit and noticed there weren’t many women featured. But then there was this picture of a woman with big glasses and cropped hair, and I thought, “Who is this?” It was Vera Rubin.

    My supervisor was a curator of oral histories. He was working on Rubin’s, so I asked him about her. He said, “I have one more oral history interview to do with her. Would you like to come?” So I got to interview her. She was charismatic, kind and curious — not a person who was all about herself, but wanted to know about you. That stuck with me.

    Temming: You spend much of the book describing evidence for dark matter besides Rubin’s research. Why?

    Yeager: I wanted to make sure I didn’t portray Rubin as this lone person who discovered dark matter, because there were a lot of different moving pieces in astronomy and physics that came together in the ’70s and early ’80s for the scientific community to say, “OK, we really have to take dark matter seriously.”

    Temming: What made Rubin’s work a linchpin for confirming dark matter?

    Yeager: She really went after nailing down that flat rotation curve in all types of galaxies. Mainly because she did get a lot of pushback, continually, that said, “Oh, that’s just a special case in that galaxy, or that’s just for those types of galaxies.” She studied hundreds of galaxies to double-check that, yes, in fact, the rotation curves are flat. People saying, “We don’t believe you,” didn’t ever really knock her down. She just came back swinging harder.

    It helped that she did the work in visible wavelengths of light. There had been a lot of radio astronomy data to suggest flat rotation curves, but because radio astronomy was very new, it was really only once you saw it with the eye that the astronomy community was convinced.

    Temming: Do you have a favorite anecdote about Rubin?

    Yeager: The one that comes to mind is how much she loved flowers. She told me about how on drives from Lowell Observatory to Kitt Peak National Observatory in Arizona, she and her colleague Kent Ford would always stop and buy wildflowers. The fact that picking these wildflowers stuck with her, I thought, was just representative of who she was. Her favorite moments weren’t necessarily these big discoveries she’d made, but stopping to pick some flowers and enjoy their beauty.

    2
    Author Ashley Yeager (left) interviewed Vera Rubin (right) in 2007 as part of an oral history project with Smithsonian’s National Air and Space Museum. Smithsonian National Air and Space Museum (NASM 9A16674).

    Temming: Did you learn anything in your research that surprised you?

    Yeager: I didn’t initially grasp how many different types of projects she had. She did a lot with looking for larger-scale structure [in the universe] and looking at the Hubble constant [which describes how fast the universe is expanding] (SN: 4/21/21). She had a very diverse set of questions that she wanted to answer, well into her 70s.

    Temming: I was surprised by her decision to get out of the rat-race of hunting for quasars, when that area of research heated up in the 1960s.

    Yeager: She very much didn’t like to be in pressure situations where she could be wrong. She liked to go and collect so much data that no one could [dispute it]. With quasar research, it was just too fast, and she wanted to be methodical about it.

    Temming: Why is Rubin’s story important to tell now?

    Yeager: Unfortunately for women and minorities in science, it’s still very relevant, in that there are a lot of challenges to pursuing a career in STEM. Her story demonstrates that you have to surround yourself with people who are willing to help you and get away from the people who want to keep you down. Plus her story is also very encouraging: Your curiosity can keep you going and can fuel something way bigger than yourself.

    Temming: How did she advocate for women in astronomy?

    Yeager: She was very outspoken about it. At National Academy of Sciences meetings, the organizers always dreaded her standing up, because she would say, “What are we doing about women in science? We’re not doing enough.” She was constantly pushing for women to be recognized with awards. She kept tabs on the number of women who had earned Ph.D.s and who had gotten staff positions — and their salaries. She was very data-driven. She’d cull that information and use it to advocate for better representation and recognition of women in astronomy.

    Temming: How would you describe Rubin to someone who hasn’t met her?

    Yeager: She was one of the most persistent, gracious and nurturing people that I’ve ever met. You could strip away all that she did in astronomy and she would still be this incredible figure — the way she carried herself, the way she treated people. Just a beautiful human being.
    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM, denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the Axion Dark Matter eXperiment U Washington (US) Credit : Mark Stone U. of Washington. Axion Dark Matter Experiment.
    ______________________________________________________________________________________________________________

    See the full article here .


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

    Please help promote STEM in your local schools.


    Stem Education Coalition

     
  • richardmitnick 8:18 am on June 26, 2021 Permalink | Reply
    Tags: "Could dark matter be behind mysterious supermassive black holes in the early universe?", , , , , Fritz Zwicky and Vera Rubin,   

    From University of Chicago (US) and From UC Riverside (US) : “Could dark matter be behind mysterious supermassive black holes in the early universe?” 

    U Chicago bloc

    From University of Chicago (US)

    and

    UC Riverside bloc

    From UC Riverside (US)

    Jun 25, 2021
    Louise Lerner

    Scientists at UChicago and University of California-Riverside (US) have put forward a surprising theory to explain mysterious, supermassive black holes that formed early in the universe; those black holes could have formed with the help of dark matter.

    1
    Illustration by European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU) + ATG Media Lab (EU).

    UChicago, UC Riverside scientists offer theory to explain the origin of monsters of the cosmos.

    When astronomers use telescopes to look back in time—toward objects in the universe whose light is only now reaching earth after billions of years—they see something odd. Black holes, big ones, that already existed when the universe was still very young.

    This is strange because from what physicists have understood, it takes time for a black hole to eat enough surrounding matter to grow so massive—so it seemed those black holes should not have had time to get so big.

    “The analogy I’ve used is that if you saw a child that was only five or six years old, but already weighed as much as an adult human,” said Hai-Bo Yu, an associate professor of physics and astronomy at University of California-Riverside.

    Yu and two other scientists with UC-Riverside and the University of Chicago came up with a surprising possible explanation [The Astrophysical Journal Letters]: Those black holes could have formed with the help of Dark Matter.

    “This ties together two great mysteries in astrophysics—early supermassive black holes and dark matter—very neatly,” said UChicago postdoctoral researcher and study co-author Yi-Ming Zhong.

    In the early days of the universe, visible matter existed as clouds of gas particles that would grow into denser objects, such as stars and galaxies. These clouds could collapse and form a seed black hole, i.e., the baby stage of a supermassive black hole. However, in this scenario, the scientists said, the seed would not have enough time to grow into the most massive black holes observed in the early universe, if it eats at a “normal” pace.

    But alongside the ordinary matter in these clouds was a halo of dark matter, a mysterious form of matter that we can tell is there because of its gravity pulls on visible things in the universe. The scientists wondered if dark matter could serve as an ingredient that helps create supermassive black holes.

    According to their simulations, if particles of dark matter in those halos were colliding with each other, such activity could tip the balance of the system towards collapse. That’s because the particles could spread heat to one another as they collided, making the central halo unstable. They also found the dark matter collisions would dissipate the halo’s angular momentum—the quantity that describes the spinning of a body—which further tips the system towards collapse.

    Such a collapse usually takes a long time. However, the presence of ordinary matter at the halo center adds extra mass that deepens the gravitational potential there, thus expediting the heat spread. “The presence of ordinary matter could shorten the collapse timescale by two orders of magnitude,” said graduate student and co-author Wei-Xiang Feng.

    These “seed” black holes would have been much more massive than those typically formed by the collapse of ordinary gas—akin to the baby in the analogy being born already weighing 100 pounds. From there, it could grow through the “normal” process of eating nearby matter.

    The scientists are investigating further implications of this theory, such as the origin of supermassive black holes in our own Milky Way and many other large nearby galaxies.

    It could also be an indication about the nature of dark matter itself; it’s difficult to directly observe whether or not dark matter particles can collide among themselves, but if this theory pans out, it could serve as evidence that they can.

    A way to test this theory might become possible as the next generation of more powerful telescopes begin taking data. For example, the Giant Magellan Telescope will be probing the growth of black holes in the universe.

    “This system has very novel and interesting dynamics, so we’re exploring further,” said Zhong. “Plus, it’s intriguing that we can address two mysteries with one theory.”

    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment


    _____________________________________________________________________________________

    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 Riverside Campus

    The University of California-Riverside (US) is a public land-grant research university in Riverside, California. It is one of the 10 campuses of the University of California (US) system. The main campus sits on 1,900 acres (769 ha) in a suburban district of Riverside with a branch campus of 20 acres (8 ha) in Palm Desert. In 1907, the predecessor to UC-Riverside was founded as the UC Citrus Experiment Station, Riverside which pioneered research in biological pest control and the use of growth regulators responsible for extending the citrus growing season in California from four to nine months. Some of the world’s most important research collections on citrus diversity and entomology, as well as science fiction and photography, are located at Riverside.

    UC-Riverside’s undergraduate College of Letters and Science opened in 1954. The Regents of the University of California declared UC-Riverside a general campus of the system in 1959, and graduate students were admitted in 1961. To accommodate an enrollment of 21,000 students by 2015, more than $730 million has been invested in new construction projects since 1999. Preliminary accreditation of the UC-Riverside School of Medicine was granted in October 2012 and the first class of 50 students was enrolled in August 2013. It is the first new research-based public medical school in 40 years.

    UC-Riverside is classified among “R1: Doctoral Universities – Very high research activity.” The 2019 U.S. News & World Report Best Colleges rankings places UC-Riverside tied for 35th among top public universities and ranks 85th nationwide. Over 27 of UC- Riverside’s academic programs, including the Graduate School of Education and the Bourns College of Engineering, are highly ranked nationally based on peer assessment, student selectivity, financial resources, and other factors. Washington Monthly ranked UC Riverside 2nd in the United States in terms of social mobility, research and community service, while U.S. News ranks UC-Riverside as the fifth most ethnically diverse and, by the number of undergraduates receiving Pell Grants (42 percent), the 15th most economically diverse student body in the nation. Over 70% of all UC-Riverside students graduate within six years without regard to economic disparity. UC-Riverside’s extensive outreach and retention programs have contributed to its reputation as a “university of choice” for minority students. In 2005, UCR became the first public university campus in the nation to offer a gender-neutral housing option. UC-Riverside’s sports teams are known as the Highlanders and play in the Big West Conference of the National Collegiate Athletic Association (NCAA) Division I. Their nickname was inspired by the high altitude of the campus, which lies on the foothills of Box Springs Mountain. The UC-Riverside women’s basketball team won back-to-back Big West championships in 2006 and 2007. In 2007, the men’s baseball team won its first conference championship and advanced to the regionals for the second time since the university moved to Division I in 2001.

    History

    At the turn of the 20th century, Southern California was a major producer of citrus, the region’s primary agricultural export. The industry developed from the country’s first navel orange trees, planted in Riverside in 1873. Lobbied by the citrus industry, the UC Regents established the UC Citrus Experiment Station (CES) on February 14, 1907, on 23 acres (9 ha) of land on the east slope of Mount Rubidoux in Riverside. The station conducted experiments in fertilization, irrigation and crop improvement. In 1917, the station was moved to a larger site, 475 acres (192 ha) near Box Springs Mountain.

    The 1944 passage of the GI Bill during World War II set in motion a rise in college enrollments that necessitated an expansion of the state university system in California. A local group of citrus growers and civic leaders, including many University of California-Berkeley(US) alumni, lobbied aggressively for a UC-administered liberal arts college next to the CES. State Senator Nelson S. Dilworth authored Senate Bill 512 (1949) which former Assemblyman Philip L. Boyd and Assemblyman John Babbage (both of Riverside) were instrumental in shepherding through the State Legislature. Governor Earl Warren signed the bill in 1949, allocating $2 million for initial campus construction.

    Gordon S. Watkins, dean of the College of Letters and Science at University of California-Los Angeles, became the first provost of the new college at Riverside. Initially conceived of as a small college devoted to the liberal arts, he ordered the campus built for a maximum of 1,500 students and recruited many young junior faculty to fill teaching positions. He presided at its opening with 65 faculty and 127 students on February 14, 1954, remarking, “Never have so few been taught by so many.”

    UC-Riverside’s enrollment exceeded 1,000 students by the time Clark Kerr became president of the University of California system in 1958. Anticipating a “tidal wave” in enrollment growth required by the baby boom generation, Kerr developed the California Master Plan for Higher Education and the Regents designated Riverside a general university campus in 1959. UC-Riverside’s first chancellor, Herman Theodore Spieth, oversaw the beginnings of the school’s transition to a full university and its expansion to a capacity of 5,000 students. UC-Riverside’s second chancellor, Ivan Hinderaker led the campus through the era of the free speech movement and kept student protests peaceful in Riverside. According to a 1998 interview with Hinderaker, the city of Riverside received negative press coverage for smog after the mayor asked Governor Ronald Reagan to declare the South Coast Air Basin a disaster area in 1971; subsequent student enrollment declined by up to 25% through 1979. Hinderaker’s development of innovative programs in business administration and biomedical sciences created incentive for enough students to enroll at UC-Riverside to keep the campus open.

    In the 1990s, the UC-Riverside experienced a new surge of enrollment applications, now known as “Tidal Wave II”. The Regents targeted UC-Riverside for an annual growth rate of 6.3%, the fastest in the UC system, and anticipated 19,900 students at UC-Riverside by 2010. By 1995, African American, American Indian, and Latino student enrollments accounted for 30% of the UC-Riverside student body, the highest proportion of any UC campus at the time. The 1997 implementation of Proposition 209—which banned the use of affirmative action by state agencies—reduced the ethnic diversity at the more selective UC campuses but further increased it at UC-Riverside.

    With UC-Riverside scheduled for dramatic population growth, efforts have been made to increase its popular and academic recognition. The students voted for a fee increase to move UC-Riverside athletics into NCAA Division I standing in 1998. In the 1990s, proposals were made to establish a law school, a medical school, and a school of public policy at UC-Riverside, with the UC-Riverside School of Medicine and the School of Public Policy becoming reality in 2012. In June 2006, UC-Riverside received its largest gift, 15.5 million from two local couples, in trust towards building its medical school. The Regents formally approved UC-Riverside’s medical school proposal in 2006. Upon its completion in 2013, it was the first new medical school built in California in 40 years.

    Academics

    As a campus of the University of California(US) system, UC-Riverside is governed by a Board of Regents and administered by a president. UC-Riverside’s academic policies are set by its Academic Senate, a legislative body composed of all UC-Riverside faculty members.

    UC-Riverside is organized into three academic colleges, two professional schools, and two graduate schools. UC-Riverside’s liberal arts college, the College of Humanities, Arts and Social Sciences, was founded in 1954, and began accepting graduate students in 1960. The College of Natural and Agricultural Sciences, founded in 1960, incorporated the CES as part of the first research-oriented institution at UC-Riverside; it eventually also incorporated the natural science departments formerly associated with the liberal arts college to form its present structure in 1974. UC-Riverside’s newest academic unit, the Bourns College of Engineering, was founded in 1989. Comprising the professional schools are the Graduate School of Education, founded in 1968, and the UC-Riverside School of Business, founded in 1970. These units collectively provide 81 majors and 52 minors, 48 master’s degree programs, and 42 Doctor of Philosophy (PhD) programs. UC-Riverside is the only UC campus to offer undergraduate degrees in creative writing and public policy and one of three UCs (along with University of California-Berkeley (US) and University of California-Irvine (US)) to offer an undergraduate degree in business administration. Through its Division of Biomedical Sciences, founded in 1974, UC-Riverside offers the Thomas Haider medical degree program in collaboration with University of California-Los Angeles(US). UC-Riverside’s doctoral program in the emerging field of dance theory, founded in 1992, was the first program of its kind in the United States, and UC-Riverside’s minor in lesbian, gay and bisexual studies, established in 1996, was the first undergraduate program of its kind in the University of California system. A new BA program in bagpipes was inaugurated in 2007.

    Research and economic impact

    UC-Riverside operated under a $727 million budget in fiscal year 2014–15. The state government provided $214 million, student fees accounted for $224 million and $100 million came from contracts and grants. Private support and other sources accounted for the remaining $189 million. Overall, monies spent at UC-Riverside have an economic impact of nearly $1 billion in California. UC-Riverside research expenditure in FY 2018 totaled $167.8 million. Total research expenditures at UC-Riverside are significantly concentrated in agricultural science, accounting for 53% of total research expenditures spent by the university in 2002. Top research centers by expenditure, as measured in 2002, include the Agricultural Experiment Station; the Center for Environmental Research and Technology; the Center for Bibliographical Studies; the Air Pollution Research Center; and the Institute of Geophysics and Planetary Physics.

    Throughout UC-Riverside’s history, researchers have developed more than 40 new citrus varieties and invented new techniques to help the $960 million-a-year California citrus industry fight pests and diseases. In 1927, entomologists at the CES introduced two wasps from Australia as natural enemies of a major citrus pest, the citrophilus mealybug, saving growers in Orange County $1 million in annual losses. This event was pivotal in establishing biological control as a practical means of reducing pest populations. In 1963, plant physiologist Charles Coggins proved that application of gibberellic acid allows fruit to remain on citrus trees for extended periods. The ultimate result of his work, which continued through the 1980s, was the extension of the citrus-growing season in California from four to nine months. In 1980, UC-Riverside released the Oroblanco grapefruit, its first patented citrus variety. Since then, the citrus breeding program has released other varieties such as the Melogold grapefruit, the Gold Nugget mandarin (or tangerine), and others that have yet to be given trademark names.

    To assist entrepreneurs in developing new products, UC-Riverside is a primary partner in the Riverside Regional Technology Park, which includes the City of Riverside and the County of Riverside. It also administers six reserves of the University of California Natural Reserve System. UC-Riverside recently announced a partnership with China Agricultural University[中国农业大学](CN) to launch a new center in Beijing, which will study ways to respond to the country’s growing environmental issues. UC-Riverside can also boast the birthplace of two name reactions in organic chemistry, the Castro-Stephens coupling and the Midland Alpine Borane Reduction.

    U Chicago Campus

    An intellectual destination

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

    The University of Chicago (US) is an urban research university that has driven new ways of thinking since 1890. Our commitment to free and open inquiry draws inspired scholars to our global campuses, where ideas are born that challenge and change the world.

    We empower individuals to challenge conventional thinking in pursuit of original ideas. Students in the College develop critical, analytic, and writing skills in our rigorous, interdisciplinary core curriculum. Through graduate programs, students test their ideas with UChicago scholars, and become the next generation of leaders in academia, industry, nonprofits, and government.

    UChicago research has led to such breakthroughs as discovering the link between cancer and genetics, establishing revolutionary theories of economics, and developing tools to produce reliably excellent urban schooling. We generate new insights for the benefit of present and future generations with our national and affiliated laboratories: DOE’s Argonne National Laboratory (US), DOE’s Fermi National Accelerator Laboratory (US), and the Marine Biological Laboratory in Woods Hole, Massachusetts.
    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts. The University of Chicago is a private research university in Chicago, Illinois. Founded in 1890, its main campus is located in Chicago’s Hyde Park neighborhood. It enrolled 16,445 students in Fall 2019, including 6,286 undergraduates and 10,159 graduate students. The University of Chicago is ranked among the top universities in the world by major education publications, and it is among the most selective in the United States.

    The university is composed of one undergraduate college and five graduate research divisions, which contain all of the university’s graduate programs and interdisciplinary committees. Chicago has eight professional schools: the Law School, the Booth School of Business, the Pritzker School of Medicine, the School of Social Service Administration, the Harris School of Public Policy, the Divinity School, the Graham School of Continuing Liberal and Professional Studies, and the Pritzker School of Molecular Engineering. The university has additional campuses and centers in London, Paris, Beijing, Delhi, and Hong Kong, as well as in downtown Chicago.

    University of Chicago scholars have played a major role in the development of many academic disciplines, including economics, law, literary criticism, mathematics, religion, sociology, and the behavioralism school of political science, establishing the Chicago schools in various fields. Chicago’s Metallurgical Laboratory produced the world’s first man-made, self-sustaining nuclear reaction in Chicago Pile-1 beneath the viewing stands of the university’s Stagg Field. Advances in chemistry led to the “radiocarbon revolution” in the carbon-14 dating of ancient life and objects. The university research efforts include administration of DOE’s Fermi National Accelerator Laboratory(US) and DOE’s Argonne National Laboratory(US), as well as the U Chicago Marine Biological Laboratory in Woods Hole, Massachusetts (MBL)(US). The university is also home to the University of Chicago Press, the largest university press in the United States. The Barack Obama Presidential Center is expected to be housed at the university and will include both the Obama presidential library and offices of the Obama Foundation.

    The University of Chicago’s students, faculty, and staff have included 100 Nobel laureates as of 2020, giving it the fourth-most affiliated Nobel laureates of any university in the world. The university’s faculty members and alumni also include 10 Fields Medalists, 4 Turing Award winners, 52 MacArthur Fellows, 26 Marshall Scholars, 27 Pulitzer Prize winners, 20 National Humanities Medalists, 29 living billionaire graduates, and have won eight Olympic medals.

    UChicago research has led to such breakthroughs as discovering the link between cancer and genetics; establishing revolutionary theories of economics; and developing tools to produce reliably excellent urban schooling. We generate new insights for the benefit of present and future generations.

    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts.

    Research

    According to the National Science Foundation (US), University of Chicago spent $423.9 million on research and development in 2018, ranking it 60th in the nation. It is classified among “R1: Doctoral Universities – Very high research activity” and is a founding member of the Association of American Universities (US) and was a member of the Committee on Institutional Cooperation from 1946 through June 29, 2016, when the group’s name was changed to the Big Ten Academic Alliance. The University of Chicago is not a member of the rebranded consortium, but will continue to be a collaborator.

    The university operates more than 140 research centers and institutes on campus. Among these are the Oriental Institute—a museum and research center for Near Eastern studies owned and operated by the university—and a number of National Resource Centers, including the Center for Middle Eastern Studies. Chicago also operates or is affiliated with several research institutions apart from the university proper. The university manages Argonne National Laboratory, part of the United States Department of Energy’s national laboratory system, and co-manages Fermi National Accelerator Laboratory (Fermilab), a nearby particle physics laboratory, as well as a stake in the Apache Point Observatory (US) in Sunspot, New Mexico. Faculty and students at the adjacent Toyota Technological Institute at Chicago collaborate with the university. In 2013, the university formed an affiliation with the formerly independent Marine Biological Laboratory in Woods Hole, Mass. Although formally unrelated, the National Opinion Research Center (US) is located on Chicago’s campus.

     
  • richardmitnick 9:50 pm on June 22, 2021 Permalink | Reply
    Tags: , , , Erik Verlinde's theory of emergent gravity, Fritz Zwicky and Vera Rubin, , , ,   

    From University of Amsterdam [Universiteit van Amsterdam] (NL): Women in STEM-Margot Brouwer “Dark matter: ‘real stuff’ or gravity misunderstood?” 

    22 June 2021

    For many years now, astronomers and physicists have been in a conflict. Is the mysterious Dark Matter that we observe deep in the Universe real, or is what we see the result of subtle deviations from the laws of gravity as we know them? In 2016, Dutch physicist Erik Verlinde proposed a theory of the second kind: emergent gravity. New research, published in Astronomy & Astrophysics this week, pushes the limits of dark matter observations to the unknown outer regions of galaxies, and in doing so re-evaluates several dark matter models and alternative theories of gravity. Measurements of the gravity of 259,000 isolated galaxies show a very close relation between the contributions of dark matter and those of ordinary matter, as predicted in Verlinde’s theory of emergent gravity and an alternative model called Modified Newtonian Dynamics. However, the results also appear to agree with a computer simulation of the Universe that assumes that dark matter is ‘real stuff’.

    1
    In the centre of the image the elliptical galaxy NGC5982, and to the right the spiral galaxy NGC5985. These two types of galaxies turn out to behave very differently when it comes to the extra gravity – and therefore possibly the dark matter – in their outer regions. Images: Bart Delsaert (www.delsaert.com).

    The new research was carried out by an international team of astronomers, led by Margot Brouwer (University of Groningen [Rijksuniversiteit Groningen] (NL) and UvA). Further important roles were played by Kyle Oman (RUG and Durham University (UK)) and Edwin Valentijn (RUG). In 2016, Brouwer also performed a first test of Verlinde’s ideas [MNRAS]; this time, Verlinde himself also joined the research team.

    Matter or gravity?

    So far, dark matter has never been observed directly – hence the name. What astronomers observe in the night sky are the consequences of matter that is potentially present: bending of starlight, stars that move faster than expected, and even effects on the motion of entire galaxies. Without a doubt all of these effects are caused by gravity, but the question is: are we truly observing additional gravity, caused by invisible matter, or are the laws of gravity themselves the thing that we haven’t fully understood yet?

    To answer this question, the new research uses a similar method to the one used in the original test in 2016. Brouwer and her colleagues make use of an ongoing series of photographic measurements that started ten years ago: the KiloDegree Survey (KiDS), performed using ESO’s VLT Survey Telescope in Chili.

    In these observations one measures how starlight from far away galaxies is bent by gravity on its way to our telescopes. Whereas in 2016 the measurements of such ‘lens effects’ only covered an area of about 180 square degrees on the night sky, in the mean time this has been extended to about 1000 square degrees – allowing the researchers to measure the distribution of gravity in around a million different galaxies.

    Comparative testing

    Brouwer and her colleagues selected over 259,000 isolated galaxies, for which they were able to measure the so-called ‘Radial Acceleration Relation’ (RAR). This RAR compares the amount of gravity expected based on the visible matter in the galaxy, to the amount of gravity that is actually present – in other words: the result shows how much ‘extra’ gravity there is, in addition to that due to normal matter. Until now, the amount of extra gravity had only been determined in the outer regions of galaxies by observing the motions of stars, and in a region about five times larger by measuring the rotational velocity of cold gas. Using the lensing effects of gravity, the researchers were now able to determine the RAR at gravitational strengths which were one hundred times smaller, allowing them to penetrate much deeper into the regions far outside the individual galaxies.

    This made it possible to measure the extra gravity extremely precisely – but is this gravity the result of invisible dark matter, or do we need to improve our understanding of gravity itself? Author Kyle Oman indicates that the assumption of ‘real stuff’ at least partially appears to work: “In our research, we compare the measurements to four different theoretical models: two that assume the existence of dark matter and form the base of computer simulations of our universe, and two that modify the laws of gravity – Erik Verlinde’s model of emergent gravity and the so-called ‘Modified Newtonian Dynamics’ or MOND. One of the two dark matter simulations, MICE, makes predictions that match our measurements very nicely. It came as a surprise to us that the other simulation, BAHAMAS, led to very different predictions. That the predictions of the two models differed at all was already surprising, since the models are so similar. But moreover, we would have expected that if a difference would show up, BAHAMAS was going to perform best. BAHAMAS is a much more detailed model than MICE, approaching our current understanding of how galaxies form in a universe with dark matter much closer. Still, MICE performs better if we compare its predictions to our measurements. In the future, based on our findings, we want to further investigate what causes the differences between the simulations.”

    Young and old galaxies

    Thus it seems that, at least one dark matter model does appear to work. However, the alternative models of gravity also predict the measured RAR. A standoff, it seems – so how do we find out which model is correct? Margot Brouwer, who led the research team, continues: “Based on our tests, our original conclusion was that the two alternative gravity models and MICE matched the observations reasonably well. However, the most exciting part was yet to come: because we had access to over 259,000 galaxies, we could divide them into several types – relatively young, blue spiral galaxies versus relatively old, red elliptical galaxies.” Those two types of galaxies come about in very different ways: red elliptical galaxies form when different galaxies interact, for example when two blue spiral galaxies pass by each other closely, or even collide. As a result, the expectation within the particle theory of dark matter is that the ratio between regular and dark matter in the different types of galaxies can vary. Models such as Verlinde’s theory and MOND on the other hand do not make use of dark matter particles, and therefore predict a fixed ratio between the expected and measured gravity in the two types of galaxies – that is, independent of their type. Brouwer: “We discovered that the RARs for the two types of galaxies differed significantly. That would be a strong hint towards the existence of dark matter as a particle.”

    2
    A plot showing the Radial Acceleration Relation (RAR). The background is an image of the elliptical galaxy M87, showing the distance to the centre of the galaxy. The plot shows how the measurements range from high gravitational acceleration in the centre of the galaxy, to low gravitational acceleration in the far outer regions. Image: Chris Mihos (Case Western Reserve University (US)) / European Southern Observatory [Observatoire européen austral][Europäische Südsternwarte] (EU) (CL).

    However, there is a caveat: gas. Many galaxies are probably surrounded by a diffuse cloud of hot gas, which is very difficult to observe. If it were the case that there is hardly any gas around young blue spiral galaxies, but that old red elliptical galaxies live in a large cloud of gas – of roughly the same mass as the stars themselves – then that could explain the difference in the RAR between the two types. To reach a final judgement on the measured difference, one would therefore also need to measure the amounts of diffuse gas – and this is exactly what is not possible using the KiDS telescopes. Other measurements have been done for a small group of around one hundred galaxies, and these measurements indeed found more gas around elliptical galaxies, but it is still unclear how representative those measurements are for the 259,000 galaxies that were studied in the current research.

    Dark matter for the win?

    If it turns out that extra gas cannot explain the difference between the two types of galaxies, then the results of the measurements are easier to understand in terms of dark matter particles than in terms of alternative models of gravity. But even then, the matter is not settled yet. While the measured differences are hard to explain using MOND, Erik Verlinde still sees a way out for his own model. Verlinde: “My current model only applies to static, isolated, spherical galaxies, so it cannot be expected to distinguish the different types of galaxies. I view these results as a challenge and inspiration to develop an asymmetric, dynamical version of my theory, in which galaxies with a different shape and history can have a different amount of ‘apparent dark matter’.”

    Therefore, even after the new measurements, the dispute between dark matter and alternative gravity theories is not settled yet. Still, the new results are a major step forward: if the measured difference in gravity between the two types of galaxies is correct, then the ultimate model, whichever one that is, will have to be precise enough to explain this difference. This means in particular that many existing models can be discarded, which considerably thins out the landscape of possible explanations. On top of that, the new research shows that systematic measurements of the hot gas around galaxies are necessary. Edwin Valentijn formulates is as follows: “As observational astronomers, we have reached the point where we are able to measure the extra gravity around galaxies more precisely than we can measure the amount of visible matter. The counterintuitive conclusion is that we must first measure the presence of ordinary matter in the form of hot gas around galaxies, before future telescopes such as Euclid can finally solve the mystery of dark matter.”

    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    _____________________________________________________________________________________

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Amsterdam [Universiteit van Amsterdam] (NL) is a public research university located in Amsterdam, Netherlands. The UvA is one of two large, publicly funded research universities in the city, the other being the Free University of Amsterdam [Vrije Universiteit Amsterdam] (NL). Established in 1632 by municipal authorities and later renamed for the city of Amsterdam, the University of Amsterdam is the third-oldest university in the Netherlands. It is one of the largest research universities in Europe with 31,186 students, 4,794 staff, 1,340 PhD students and an annual budget of €600 million. It is the largest university in the Netherlands by enrollment. The main campus is located in central Amsterdam, with a few faculties located in adjacent boroughs. The university is organised into seven faculties: Humanities, Social and Behavioural Sciences, Economics and Business, Science, Law, Medicine, Dentistry.

    The University of Amsterdam has produced six Nobel Laureates and five prime ministers of the Netherlands. The university has been placed in the top 100 universities in the world by five major ranking tables. By the QS World University Rankings it was ranked 55th in the world, 14th in Europe, and 1st in the Netherlands in 2022. The UvA was placed in the top 50 worldwide in seven fields in the 2011 QS World University Rankings in the fields of linguistics, sociology, philosophy, geography, science, Economics and econometrics, and accountancy and finance. In 2018 and 2019 the two departments of Media and Communication were commonly ranked 1st in the world by subject by QS Ranking.

    Close ties are harbored with other institutions internationally through its membership in the League of European Research Universities (LERU), the Institutional Network of the Universities from the Capitals of Europe (EU) (UNICA), European University Association (EUA) (EU), the International Student Exchange Programs (ISEP), and Universitas 21.

    Research

    The University of Amsterdam is one of Europe’s largest research universities, with over 7,900 scientific publications in 2010. The university spends about €100 million on research each year via direct funding. It receives an additional €23 million via indirect funding and about €49 million from commercial partners. Faculty members often receive research prizes and grants, such as those from the Dutch Research Council (NWO – Nederlandse Organisatie voor Wetenschappelijk Onderzoek)(NL). Research is organized into fifteen research priority areas and 28 research institutes within the faculties oversee this research.

    The University of Amsterdam has an extensive central University Library (UBA), with over four million volumes. In addition, a number of departments have their own libraries. The main university library is located in the city center. It contains over four million books, 70,000 manuscripts, 500,000 letters, and 125,000 maps, as well as special collections of the Department of Rare and Precious Works, the Manuscript and Writing Museum, the Bibliotheca Rosenthaliana on Jewish history and culture, and the Department of Documentation on Social Movements. Three reading rooms are available for students to study in quiet. In addition to the main University Library, there are approximately 70 departmental libraries spread throughout the center of Amsterdam. The university’s printing arm, the Amsterdam University Press, has a publishing list of over 1,400 titles in both Dutch and English.

     
  • richardmitnick 11:10 am on June 17, 2021 Permalink | Reply
    Tags: "Mystery of Galaxy's Missing Dark Matter Deepens", , , , Fritz Zwicky and Vera Rubin, , , The spheroidal galaxy NGC 1052-DF2   

    From NASA/ESA Hubble Telescope: “Mystery of Galaxy’s Missing Dark Matter Deepens” 

    From NASA/ESA Hubble Telescope

    June 17, 2021
    MEDIA CONTACT:

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland

    SCIENCE CONTACT:

    Zili Shen
    Yale University, New Haven, Connecticut

    Shany Danieli
    Institute for Advanced Study, Princeton, New Jersey

    Pieter van Dokkum
    Yale University, New Haven, Connecticut

    1
    NGC1052-DF2 Compass Image.
    Credits:
    SCIENCE: Zili Shen (Yale Unversity (US)), Shany Danieli (Institute for Advanced Study (US)), Pieter van Dokkum (Yale)National Aeronautics Space Agency (US), European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU), Space Telescope Science Institute (US),
    IMAGE PROCESSING: Alyssa Pagan (STScI)

    Summary
    Precise Distance to Galaxy Bolsters Missing Dark Matter Claim

    What if oceanographers found the “tip” of an iceberg and nothing else? Mysteriously missing was the iceberg’s immense body, which extends far below the waves.

    Astronomers faced this puzzle when they aimed Hubble at the spheroidal galaxy NGC 1052-DF2, or DF2. It looks like a denizen of intergalactic space that is the closest thing there is to nothing, but is still something. It’s physically larger than our Milky Way, but its loose beehive swarm of stars is so thinly scattered that Hubble sees right through it, capturing myriad background galaxies.

    The missing “bottom of the iceberg” for DF2 is the lack of dark matter. Galaxies are partly made up of visible matter—stars and gas. But the bulk of a galaxy’s makeup is in dark matter, the invisible glue that keeps a lid on stars, so they don’t escape from the galaxy.

    Because this innocuous galaxy challenges conventional theories of how galaxies are put together, astronomers were naturally skeptical when it was first announced that the universe harbored such a rule breaker. After all, the entire cosmos is built on the invisible scaffolding of dark matter.

    To double-check their conclusion, the researchers used a lot more Hubble exposures to better nail down the distance to the stealthy galaxy. If DF2 were closer than they thought, the dark matter mystery goes away.

    They actually found that the galaxy is a little bit farther away than first measured. The researchers say the new milepost helps them confirm that dark matter is really missing in the galactic oddball. They say it’s now up to theorists to figure out why.
    ______________________________________________________________________________________________________________

    When astronomers using NASA’s Hubble Space Telescope uncovered an oddball galaxy that looked like it didn’t have much dark matter, some thought the finding was hard to believe and looked for a simpler explanation.

    Dark matter, after all, is the invisible glue that makes up the bulk of the universe’s matter. All galaxies appear to be dominated by it; in fact, galaxies are thought to form inside immense halos of dark matter.

    So, finding a galaxy lacking the invisible stuff is an extraordinary claim that challenges conventional wisdom. It would have the potential to upset theories of galaxy formation and evolution.

    To bolster their original finding, first reported in 2018 (Dark Matter Goes Missing in Oddball Galaxy (hubblesite.org) Nature), a team of scientists led by Pieter van Dokkum of Yale University (US) in New Haven, Connecticut, followed up their initial study with a more robust Hubble look at the galaxy, named NGC 1052-DF2. Scientists refer to it simply as “DF2.”

    “We went out on a limb with our initial Hubble observations of this galaxy in 2018,” van Dokkum said. “I think people were right to question it because it’s such an unusual result. It would be nice if there were a simple explanation, like a wrong distance. But I think it’s more fun and more interesting if it actually is a weird galaxy.”

    Determining the amount of the galaxy’s dark matter hinges on accurate measurements of how far away it is from Earth.

    If DF2 is as far from Earth as van Dokkum’s team asserts, the galaxy’s dark-matter content may only be a few percent. The team’s conclusion is based on the motions of the stars within the galaxy; their velocities are influenced by the pull of gravity. The researchers found that the observed number of stars accounts for the galaxy’s total mass, and there’s not much room left for dark matter.

    However, if DF2 were closer to Earth, as some astronomers claim, it would be intrinsically fainter and less massive. The galaxy, therefore, would need dark matter to account for the observed effects of the total mass.

    A Better Yardstick

    Team member Zili Shen, from Yale University, says that the new Hubble observations help them confirm that DF2 is not only farther from Earth than some astronomers suggest, but also slightly more distant than the team’s original estimates.

    The new distance estimate is that DF2 is 72 million light-years as opposed to 42 million light-years, as reported by other independent teams. This places the galaxy farther than the original Hubble 2018 estimate of 65 light-years distance.

    The research team based its new result on long exposures with Hubble’s Advanced Camera for Surveys, which provide a deeper view of the galaxy for finding a reliable yardstick to nail down the distance.

    They targeted aging red giant stars on the outskirts of the galaxy that all reach the same peak brightness in their evolution. Astronomers can use the stars’ intrinsic brightness to calculate vast intergalactic distances. “Studying the brightest red giants is a well-established distance indicator for nearby galaxies,” Shen explained.

    The more accurate Hubble measurements solidify the researchers’ initial conclusion of a galaxy deficient in dark matter, team members say. So the mystery of why DF2 is missing most of its dark matter still persists.

    “For almost every galaxy we look at, we say that we can’t see most of the mass because it’s dark matter,” van Dokkum explained. “What you see is only the tip of the iceberg with Hubble. But in this case, what you see is what you get. Hubble really shows the entire thing. That’s it. It’s not just the tip of the iceberg, it’s the whole iceberg.”

    The team’s science paper has appeared in the The Astrophysical Journal Letters.

    A Stealthy Galaxy

    DF2 is a giant cosmic cotton ball that van Dokkum calls a “see-through galaxy,” where the stars are spread out. The galactic oddball is almost as wide as the Milky Way, but it contains only 1/200th the number of stars as our galaxy.

    The ghostly galaxy doesn’t appear to have a noticeable central region, spiral arms, or a disk. The team estimates that DF2 contains at most 1/400th the amount of dark matter than astronomers had expected. How the galaxy formed remains a complete mystery based on the team’s latest measurements.

    DF2 isn’t the only galaxy devoid of dark matter. Shany Danieli of the Institute for Advanced Study in Princeton, New Jersey, used Hubble in 2020 to obtain an accurate distance to another ghostly galaxy, called NGC 1052-DF4 (or simply DF4), which apparently lacks dark matter, too.

    The researchers think both DF2 and DF4 were members of a collection of galaxies. However, the new Hubble observations show that the two galaxies are 6.5 million light-years away from each other, farther apart than they first thought. It also appears that DF2 has drifted away from the grouping and is isolated in space.

    Both galaxies were discovered with the Dragonfly Telephoto Array at the New Mexico Skies observatory.

    “Both of them probably were in the same group and formed at the same time,” Danieli said. “So maybe there was something special in the environment where they were formed.”

    The researchers are hunting for more of these oddball galaxies. Other teams of astronomers are searching, too. In 2020, a group of researchers uncovered 19 unusual dwarf galaxies they say are deficient in dark matter[The Astrophysical Journal Letters]. However, it will take uncovering many more dark matter-less galaxies to resolve the mystery.

    Nevertheless, van Dokkum thinks finding a galaxy lacking dark matter tells astronomers something about the invisible substance. “In our 2018 paper, we suggested that if you have a galaxy without dark matter, and other similar galaxies seem to have it, that means that dark matter is actually real and it exists,” van Dokkum said. “It’s not a mirage.”

    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    _____________________________________________________________________________________

    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 NASA/ESA Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA’s Great Observatories, along with the NASA Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the NASA Spitzer Infared Space Telescope.



    Edwin Hubble at Caltech Palomar Samuel Oschin 48 inch Telescope(US). Credit: Emilio Segre Visual Archives/AIP/SPL).

    Hubble features a 2.4-meter (7.9 ft) mirror, and its four main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble’s orbit outside the distortion of Earth’s atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe.

    The Hubble telescope was built by the United States space agency National Aeronautics Space Agency(US) with contributions from the European Space Agency [Agence spatiale européenne](EU). The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the NASA Goddard Space Flight Center(US) controls the spacecraft. Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster. It was finally launched by Space Shuttle Discovery in 1990, but its main mirror had been ground incorrectly, resulting in spherical aberration that compromised the telescope’s capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.

    Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments. The fifth mission was initially canceled on safety grounds following the Columbia disaster (2003), but NASA administrator Michael D. Griffin approved the fifth servicing mission which was completed in 2009. The telescope was still operating as of April 24, 2020, its 30th anniversary, and could last until 2030–2040. One successor to the Hubble telescope is the National Aeronautics Space Agency(USA)/European Space Agency [Agence spatiale européenne](EU)/Canadian Space Agency(CA) Webb Infrared Space Telescope scheduled for launch in October 2021.

    Proposals and precursors

    In 1923, Hermann Oberth—considered a father of modern rocketry, along with Robert H. Goddard and Konstantin Tsiolkovsky—published Die Rakete zu den Planetenräumen (“The Rocket into Planetary Space“), which mentioned how a telescope could be propelled into Earth orbit by a rocket.

    The history of the Hubble Space Telescope can be traced back as far as 1946, to astronomer Lyman Spitzer’s paper entitled Astronomical advantages of an extraterrestrial observatory. In it, he discussed the two main advantages that a space-based observatory would have over ground-based telescopes. First, the angular resolution (the smallest separation at which objects can be clearly distinguished) would be limited only by diffraction, rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as seeing. At that time ground-based telescopes were limited to resolutions of 0.5–1.0 arcseconds, compared to a theoretical diffraction-limited resolution of about 0.05 arcsec for an optical telescope with a mirror 2.5 m (8.2 ft) in diameter. Second, a space-based telescope could observe infrared and ultraviolet light, which are strongly absorbed by the atmosphere.

    Spitzer devoted much of his career to pushing for the development of a space telescope. In 1962, a report by the U.S. National Academy of Sciences recommended development of a space telescope as part of the space program, and in 1965 Spitzer was appointed as head of a committee given the task of defining scientific objectives for a large space telescope.

    Space-based astronomy had begun on a very small scale following World War II, as scientists made use of developments that had taken place in rocket technology. The first ultraviolet spectrum of the Sun was obtained in 1946, and the National Aeronautics and Space Administration (US) launched the Orbiting Solar Observatory (OSO) to obtain UV, X-ray, and gamma-ray spectra in 1962.

    An orbiting solar telescope was launched in 1962 by the United Kingdom as part of the Ariel space program, and in 1966 NASA launched the first Orbiting Astronomical Observatory (OAO) mission. OAO-1’s battery failed after three days, terminating the mission. It was followed by OAO-2, which carried out ultraviolet observations of stars and galaxies from its launch in 1968 until 1972, well beyond its original planned lifetime of one year.

    The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy. In 1968, NASA developed firm plans for a space-based reflecting telescope with a mirror 3 m (9.8 ft) in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for crewed maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable Space Shuttle indicated that the technology to allow this was soon to become available.

    Quest for funding

    The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.
    In response a nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually the Senate agreed to half the budget that had originally been approved by Congress.

    The funding issues led to something of a reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m (4.9 ft) space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency. ESA agreed to provide funding and supply one of the first generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983 the telescope was named after Edwin Hubble, who confirmed one of the greatest scientific discoveries of the 20th century, made by Georges Lemaître, that the universe is expanding.

    Construction and engineering

    Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. NASA Marshall Space Flight Center (MSFC) was given responsibility for the design, development, and construction of the telescope, while Goddard Space Flight Center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed.

    Optical Telescope Assembly

    Optically, the HST is a Cassegrain reflector of Ritchey–Chrétien design, as are most large professional telescopes. This design, with two hyperbolic mirrors, is known for good imaging performance over a wide field of view, with the disadvantage that the mirrors have shapes that are hard to fabricate and test. The mirror and optical systems of the telescope determine the final performance, and they were designed to exacting specifications. Optical telescopes typically have mirrors polished to an accuracy of about a tenth of the wavelength of visible light, but the Space Telescope was to be used for observations from the visible through the ultraviolet (shorter wavelengths) and was specified to be diffraction limited to take full advantage of the space environment. Therefore, its mirror needed to be polished to an accuracy of 10 nanometers, or about 1/65 of the wavelength of red light. On the long wavelength end, the OTA was not designed with optimum IR performance in mind—for example, the mirrors are kept at stable (and warm, about 15 °C) temperatures by heaters. This limits Hubble’s performance as an infrared telescope.

    Perkin-Elmer intended to use custom-built and extremely sophisticated computer-controlled polishing machines to grind the mirror to the required shape. However, in case their cutting-edge technology ran into difficulties, NASA demanded that PE sub-contract to Kodak to construct a back-up mirror using traditional mirror-polishing techniques. (The team of Kodak and Itek also bid on the original mirror polishing work. Their bid called for the two companies to double-check each other’s work, which would have almost certainly caught the polishing error that later caused such problems.) The Kodak mirror is now on permanent display at the National Air and Space Museum. An Itek mirror built as part of the effort is now used in the 2.4 m telescope at the Magdalena Ridge Observatory.

    Construction of the Perkin-Elmer mirror began in 1979, starting with a blank manufactured by Corning from their ultra-low expansion glass. To keep the mirror’s weight to a minimum it consisted of top and bottom plates, each one inch (25 mm) thick, sandwiching a honeycomb lattice. Perkin-Elmer simulated microgravity by supporting the mirror from the back with 130 rods that exerted varying amounts of force. This ensured the mirror’s final shape would be correct and to specification when finally deployed. Mirror polishing continued until May 1981. NASA reports at the time questioned Perkin-Elmer’s managerial structure, and the polishing began to slip behind schedule and over budget. To save money, NASA halted work on the back-up mirror and put the launch date of the telescope back to October 1984. The mirror was completed by the end of 1981; it was washed using 2,400 US gallons (9,100 L) of hot, deionized water and then received a reflective coating of 65 nm-thick aluminum and a protective coating of 25 nm-thick magnesium fluoride.

    Doubts continued to be expressed about Perkin-Elmer’s competence on a project of this importance, as their budget and timescale for producing the rest of the OTA continued to inflate. In response to a schedule described as “unsettled and changing daily”, NASA postponed the launch date of the telescope until April 1985. Perkin-Elmer’s schedules continued to slip at a rate of about one month per quarter, and at times delays reached one day for each day of work. NASA was forced to postpone the launch date until March and then September 1986. By this time, the total project budget had risen to US$1.175 billion.

    Spacecraft systems

    The spacecraft in which the telescope and instruments were to be housed was another major engineering challenge. It would have to withstand frequent passages from direct sunlight into the darkness of Earth’s shadow, which would cause major changes in temperature, while being stable enough to allow extremely accurate pointing of the telescope. A shroud of multi-layer insulation keeps the temperature within the telescope stable and surrounds a light aluminum shell in which the telescope and instruments sit. Within the shell, a graphite-epoxy frame keeps the working parts of the telescope firmly aligned. Because graphite composites are hygroscopic, there was a risk that water vapor absorbed by the truss while in Lockheed’s clean room would later be expressed in the vacuum of space; resulting in the telescope’s instruments being covered by ice. To reduce that risk, a nitrogen gas purge was performed before launching the telescope into space.

    While construction of the spacecraft in which the telescope and instruments would be housed proceeded somewhat more smoothly than the construction of the OTA, Lockheed still experienced some budget and schedule slippage, and by the summer of 1985, construction of the spacecraft was 30% over budget and three months behind schedule. An MSFC report said Lockheed tended to rely on NASA directions rather than take their own initiative in the construction.

    Computer systems and data processing

    The two initial, primary computers on the HST were the 1.25 MHz DF-224 system, built by Rockwell Autonetics, which contained three redundant CPUs, and two redundant NSSC-1 (NASA Standard Spacecraft Computer, Model 1) systems, developed by Westinghouse and GSFC using diode–transistor logic (DTL). A co-processor for the DF-224 was added during Servicing Mission 1 in 1993, which consisted of two redundant strings of an Intel-based 80386 processor with an 80387 math co-processor. The DF-224 and its 386 co-processor were replaced by a 25 MHz Intel-based 80486 processor system during Servicing Mission 3A in 1999. The new computer is 20 times faster, with six times more memory, than the DF-224 it replaced. It increases throughput by moving some computing tasks from the ground to the spacecraft and saves money by allowing the use of modern programming languages.

    Additionally, some of the science instruments and components had their own embedded microprocessor-based control systems. The MATs (Multiple Access Transponder) components, MAT-1 and MAT-2, utilize Hughes Aircraft CDP1802CD microprocessors. The Wide Field and Planetary Camera (WFPC) also utilized an RCA 1802 microprocessor (or possibly the older 1801 version). The WFPC-1 was replaced by the WFPC-2 [below] during Servicing Mission 1 in 1993, which was then replaced by the Wide Field Camera 3 (WFC3) [below] during Servicing Mission 4 in 2009.

    Initial instruments

    When launched, the HST carried five scientific instruments: the Wide Field and Planetary Camera (WF/PC), Goddard High Resolution Spectrograph (GHRS), High Speed Photometer (HSP), Faint Object Camera (FOC) and the Faint Object Spectrograph (FOS). WF/PC was a high-resolution imaging device primarily intended for optical observations. It was built by NASA JPL-Caltech(US), and incorporated a set of 48 filters isolating spectral lines of particular astrophysical interest. The instrument contained eight charge-coupled device (CCD) chips divided between two cameras, each using four CCDs. Each CCD has a resolution of 0.64 megapixels. The wide field camera (WFC) covered a large angular field at the expense of resolution, while the planetary camera (PC) took images at a longer effective focal length than the WF chips, giving it a greater magnification.

    The GHRS was a spectrograph designed to operate in the ultraviolet. It was built by the Goddard Space Flight Center and could achieve a spectral resolution of 90,000. Also optimized for ultraviolet observations were the FOC and FOS, which were capable of the highest spatial resolution of any instruments on Hubble. Rather than CCDs these three instruments used photon-counting digicons as their detectors. The FOC was constructed by ESA, while the University of California, San Diego(US), and Martin Marietta Corporation built the FOS.

    The final instrument was the HSP, designed and built at the University of Wisconsin–Madison(US). It was optimized for visible and ultraviolet light observations of variable stars and other astronomical objects varying in brightness. It could take up to 100,000 measurements per second with a photometric accuracy of about 2% or better.

    HST’s guidance system can also be used as a scientific instrument. Its three Fine Guidance Sensors (FGS) are primarily used to keep the telescope accurately pointed during an observation, but can also be used to carry out extremely accurate astrometry; measurements accurate to within 0.0003 arcseconds have been achieved.

    Ground support

    The Space Telescope Science Institute (STScI) is responsible for the scientific operation of the telescope and the delivery of data products to astronomers. STScI is operated by the Association of Universities for Research in Astronomy(US) (AURA) and is physically located in Baltimore, Maryland on the Homewood campus of Johns Hopkins University(US), one of the 39 U.S. universities and seven international affiliates that make up the AURA consortium. STScI was established in 1981 after something of a power struggle between NASA and the scientific community at large. NASA had wanted to keep this function in-house, but scientists wanted it to be based in an academic establishment. The Space Telescope European Coordinating Facility (ST-ECF), established at Garching bei München near Munich in 1984, provided similar support for European astronomers until 2011, when these activities were moved to the European Space Astronomy Centre.

    One rather complex task that falls to STScI is scheduling observations for the telescope. Hubble is in a low-Earth orbit to enable servicing missions, but this means most astronomical targets are occulted by the Earth for slightly less than half of each orbit. Observations cannot take place when the telescope passes through the South Atlantic Anomaly due to elevated radiation levels, and there are also sizable exclusion zones around the Sun (precluding observations of Mercury), Moon and Earth. The solar avoidance angle is about 50°, to keep sunlight from illuminating any part of the OTA. Earth and Moon avoidance keeps bright light out of the FGSs, and keeps scattered light from entering the instruments. If the FGSs are turned off, the Moon and Earth can be observed. Earth observations were used very early in the program to generate flat-fields for the WFPC1 instrument. There is a so-called continuous viewing zone (CVZ), at roughly 90° to the plane of Hubble’s orbit, in which targets are not occulted for long periods.

    Challenger disaster, delays, and eventual launch

    By January 1986, the planned launch date of October looked feasible, but the Challenger explosion brought the U.S. space program to a halt, grounding the Shuttle fleet and forcing the launch of Hubble to be postponed for several years. The telescope had to be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about US$6 million per month) pushed the overall costs of the project even higher. This delay did allow time for engineers to perform extensive tests, swap out a possibly failure-prone battery, and make other improvements. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch.

    Eventually, following the resumption of shuttle flights in 1988, the launch of the telescope was scheduled for 1990. On April 24, 1990, Space Shuttle Discovery successfully launched it during the STS-31 mission.

    From its original total cost estimate of about US$400 million, the telescope cost about US$4.7 billion by the time of its launch. Hubble’s cumulative costs were estimated to be about US$10 billion in 2010, twenty years after launch.

    List of Hubble instruments

    Hubble accommodates five science instruments at a given time, plus the Fine Guidance Sensors, which are mainly used for aiming the telescope but are occasionally used for scientific astrometry measurements. Early instruments were replaced with more advanced ones during the Shuttle servicing missions. COSTAR was a corrective optics device rather than a science instrument, but occupied one of the five instrument bays.
    Since the final servicing mission in 2009, the four active instruments have been ACS, COS, STIS and WFC3. NICMOS is kept in hibernation, but may be revived if WFC3 were to fail in the future.

    Advanced Camera for Surveys (ACS; 2002–present)
    Cosmic Origins Spectrograph (COS; 2009–present)
    Corrective Optics Space Telescope Axial Replacement (COSTAR; 1993–2009)
    Faint Object Camera (FOC; 1990–2002)
    Faint Object Spectrograph (FOS; 1990–1997)
    Fine Guidance Sensor (FGS; 1990–present)
    Goddard High Resolution Spectrograph (GHRS/HRS; 1990–1997)
    High Speed Photometer (HSP; 1990–1993)
    Near Infrared Camera and Multi-Object Spectrometer (NICMOS; 1997–present, hibernating since 2008)
    Space Telescope Imaging Spectrograph (STIS; 1997–present (non-operative 2004–2009))
    Wide Field and Planetary Camera (WFPC; 1990–1993)
    Wide Field and Planetary Camera 2 (WFPC2; 1993–2009)
    Wide Field Camera 3 (WFC3; 2009–present)

    Of the former instruments, three (COSTAR, FOS and WFPC2) are displayed in the Smithsonian National Air and Space Museum. The FOC is in the Dornier museum, Germany. The HSP is in the Space Place at the University of Wisconsin–Madison. The first WFPC was dismantled, and some components were then re-used in WFC3.

    Flawed mirror

    Within weeks of the launch of the telescope, the returned images indicated a serious problem with the optical system. Although the first images appeared to be sharper than those of ground-based telescopes, Hubble failed to achieve a final sharp focus and the best image quality obtained was drastically lower than expected. Images of point sources spread out over a radius of more than one arcsecond, instead of having a point spread function (PSF) concentrated within a circle 0.1 arcseconds (485 nrad) in diameter, as had been specified in the design criteria.

    Analysis of the flawed images revealed that the primary mirror had been polished to the wrong shape. Although it was believed to be one of the most precisely figured optical mirrors ever made, smooth to about 10 nanometers, the outer perimeter was too flat by about 2200 nanometers (about 1⁄450 mm or 1⁄11000 inch). This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on a different point from the light reflecting off its center.

    The effect of the mirror flaw on scientific observations depended on the particular observation—the core of the aberrated PSF was sharp enough to permit high-resolution observations of bright objects, and spectroscopy of point sources was affected only through a sensitivity loss. However, the loss of light to the large, out-of-focus halo severely reduced the usefulness of the telescope for faint objects or high-contrast imaging. This meant nearly all the cosmological programs were essentially impossible, since they required observation of exceptionally faint objects. This led politicians to question NASA’s competence, scientists to rue the cost which could have gone to more productive endeavors, and comedians to make jokes about NASA and the telescope − in the 1991 comedy The Naked Gun 2½: The Smell of Fear, in a scene where historical disasters are displayed, Hubble is pictured with RMS Titanic and LZ 129 Hindenburg. Nonetheless, during the first three years of the Hubble mission, before the optical corrections, the telescope still carried out a large number of productive observations of less demanding targets. The error was well characterized and stable, enabling astronomers to partially compensate for the defective mirror by using sophisticated image processing techniques such as deconvolution.

    Origin of the problem

    A commission headed by Lew Allen, director of the Jet Propulsion Laboratory, was established to determine how the error could have arisen. The Allen Commission found that a reflective null corrector, a testing device used to achieve a properly shaped non-spherical mirror, had been incorrectly assembled—one lens was out of position by 1.3 mm (0.051 in). During the initial grinding and polishing of the mirror, Perkin-Elmer analyzed its surface with two conventional refractive null correctors. However, for the final manufacturing step (figuring), they switched to the custom-built reflective null corrector, designed explicitly to meet very strict tolerances. The incorrect assembly of this device resulted in the mirror being ground very precisely but to the wrong shape. A few final tests, using the conventional null correctors, correctly reported spherical aberration. But these results were dismissed, thus missing the opportunity to catch the error, because the reflective null corrector was considered more accurate.

    The commission blamed the failings primarily on Perkin-Elmer. Relations between NASA and the optics company had been severely strained during the telescope construction, due to frequent schedule slippage and cost overruns. NASA found that Perkin-Elmer did not review or supervise the mirror construction adequately, did not assign its best optical scientists to the project (as it had for the prototype), and in particular did not involve the optical designers in the construction and verification of the mirror. While the commission heavily criticized Perkin-Elmer for these managerial failings, NASA was also criticized for not picking up on the quality control shortcomings, such as relying totally on test results from a single instrument.

    Design of a solution

    Many feared that Hubble would be abandoned. The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to the problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly the same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as “spectacles” to correct the spherical aberration.

    The first step was a precise characterization of the error in the main mirror. Working backwards from images of point sources, astronomers determined that the conic constant of the mirror as built was −1.01390±0.0002, instead of the intended −1.00230. The same number was also derived by analyzing the null corrector used by Perkin-Elmer to figure the mirror, as well as by analyzing interferograms obtained during ground testing of the mirror.

    Because of the way the HST’s instruments were designed, two different sets of correctors were required. The design of the Wide Field and Planetary Camera 2, already planned to replace the existing WF/PC, included relay mirrors to direct light onto the four separate charge-coupled device (CCD) chips making up its two cameras. An inverse error built into their surfaces could completely cancel the aberration of the primary. However, the other instruments lacked any intermediate surfaces that could be figured in this way, and so required an external correction device.

    The Corrective Optics Space Telescope Axial Replacement (COSTAR) system was designed to correct the spherical aberration for light focused at the FOC, FOS, and GHRS. It consists of two mirrors in the light path with one ground to correct the aberration. To fit the COSTAR system onto the telescope, one of the other instruments had to be removed, and astronomers selected the High Speed Photometer to be sacrificed. By 2002, all the original instruments requiring COSTAR had been replaced by instruments with their own corrective optics. COSTAR was removed and returned to Earth in 2009 where it is exhibited at the National Air and Space Museum. The area previously used by COSTAR is now occupied by the Cosmic Origins Spectrograph.

    Servicing missions and new instruments

    Servicing Mission 1

    The first Hubble serving mission was scheduled for 1993 before the mirror problem was discovered. It assumed greater importance, as the astronauts would need to do extensive work to install corrective optics; failure would have resulted in either abandoning Hubble or accepting its permanent disability. Other components failed before the mission, causing the repair cost to rise to $500 million (not including the cost of the shuttle flight). A successful repair would help demonstrate the viability of building Space Station Alpha, however.

    STS-49 in 1992 demonstrated the difficulty of space work. While its rescue of Intelsat 603 received praise, the astronauts had taken possibly reckless risks in doing so. Neither the rescue nor the unrelated assembly of prototype space station components occurred as the astronauts had trained, causing NASA to reassess planning and training, including for the Hubble repair. The agency assigned to the mission Story Musgrave—who had worked on satellite repair procedures since 1976—and six other experienced astronauts, including two from STS-49. The first mission director since Project Apollo would coordinate a crew with 16 previous shuttle flights. The astronauts were trained to use about a hundred specialized tools.

    Heat had been the problem on prior spacewalks, which occurred in sunlight. Hubble needed to be repaired out of sunlight. Musgrave discovered during vacuum training, seven months before the mission, that spacesuit gloves did not sufficiently protect against the cold of space. After STS-57 confirmed the issue in orbit, NASA quickly changed equipment, procedures, and flight plan. Seven total mission simulations occurred before launch, the most thorough preparation in shuttle history. No complete Hubble mockup existed, so the astronauts studied many separate models (including one at the Smithsonian) and mentally combined their varying and contradictory details. Service Mission 1 flew aboard Endeavour in December 1993, and involved installation of several instruments and other equipment over ten days.

    Most importantly, the High Speed Photometer was replaced with the COSTAR corrective optics package, and WFPC was replaced with the Wide Field and Planetary Camera 2 (WFPC2) with an internal optical correction system. The solar arrays and their drive electronics were also replaced, as well as four gyroscopes in the telescope pointing system, two electrical control units and other electrical components, and two magnetometers. The onboard computers were upgraded with added coprocessors, and Hubble’s orbit was boosted.

    On January 13, 1994, NASA declared the mission a complete success and showed the first sharper images. The mission was one of the most complex performed up until that date, involving five long extra-vehicular activity periods. Its success was a boon for NASA, as well as for the astronomers who now had a more capable space telescope.

    Servicing Mission 2

    Servicing Mission 2, flown by Discovery in February 1997, replaced the GHRS and the FOS with the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), replaced an Engineering and Science Tape Recorder with a new Solid State Recorder, and repaired thermal insulation. NICMOS contained a heat sink of solid nitrogen to reduce the thermal noise from the instrument, but shortly after it was installed, an unexpected thermal expansion resulted in part of the heat sink coming into contact with an optical baffle. This led to an increased warming rate for the instrument and reduced its original expected lifetime of 4.5 years to about two years.

    Servicing Mission 3A

    Servicing Mission 3A, flown by Discovery, took place in December 1999, and was a split-off from Servicing Mission 3 after three of the six onboard gyroscopes had failed. The fourth failed a few weeks before the mission, rendering the telescope incapable of performing scientific observations. The mission replaced all six gyroscopes, replaced a Fine Guidance Sensor and the computer, installed a Voltage/temperature Improvement Kit (VIK) to prevent battery overcharging, and replaced thermal insulation blankets.

    Servicing Mission 3B

    Servicing Mission 3B flown by Columbia in March 2002 saw the installation of a new instrument, with the FOC (which, except for the Fine Guidance Sensors when used for astrometry, was the last of the original instruments) being replaced by the Advanced Camera for Surveys (ACS). This meant COSTAR was no longer required, since all new instruments had built-in correction for the main mirror aberration. The mission also revived NICMOS by installing a closed-cycle cooler and replaced the solar arrays for the second time, providing 30 percent more power.

    Servicing Mission 4

    Plans called for Hubble to be serviced in February 2005, but the Columbia disaster in 2003, in which the orbiter disintegrated on re-entry into the atmosphere, had wide-ranging effects on the Hubble program. NASA Administrator Sean O’Keefe decided all future shuttle missions had to be able to reach the safe haven of the International Space Station should in-flight problems develop. As no shuttles were capable of reaching both HST and the space station during the same mission, future crewed service missions were canceled. This decision was criticised by numerous astronomers who felt Hubble was valuable enough to merit the human risk. HST’s planned successor, the James Webb Telescope (JWST), as of 2004 was not expected to launch until at least 2011. A gap in space-observing capabilities between a decommissioning of Hubble and the commissioning of a successor was of major concern to many astronomers, given the significant scientific impact of HST. The consideration that JWST will not be located in low Earth orbit, and therefore cannot be easily upgraded or repaired in the event of an early failure, only made concerns more acute. On the other hand, many astronomers felt strongly that servicing Hubble should not take place if the expense were to come from the JWST budget.

    In January 2004, O’Keefe said he would review his decision to cancel the final servicing mission to HST, due to public outcry and requests from Congress for NASA to look for a way to save it. The National Academy of Sciences convened an official panel, which recommended in July 2004 that the HST should be preserved despite the apparent risks. Their report urged “NASA should take no actions that would preclude a space shuttle servicing mission to the Hubble Space Telescope”. In August 2004, O’Keefe asked Goddard Space Flight Center to prepare a detailed proposal for a robotic service mission. These plans were later canceled, the robotic mission being described as “not feasible”. In late 2004, several Congressional members, led by Senator Barbara Mikulski, held public hearings and carried on a fight with much public support (including thousands of letters from school children across the U.S.) to get the Bush Administration and NASA to reconsider the decision to drop plans for a Hubble rescue mission.

    The nomination in April 2005 of a new NASA Administrator, Michael D. Griffin, changed the situation, as Griffin stated he would consider a crewed servicing mission. Soon after his appointment Griffin authorized Goddard to proceed with preparations for a crewed Hubble maintenance flight, saying he would make the final decision after the next two shuttle missions. In October 2006 Griffin gave the final go-ahead, and the 11-day mission by Atlantis was scheduled for October 2008. Hubble’s main data-handling unit failed in September 2008, halting all reporting of scientific data until its back-up was brought online on October 25, 2008. Since a failure of the backup unit would leave the HST helpless, the service mission was postponed to incorporate a replacement for the primary unit.

    Servicing Mission 4 (SM4), flown by Atlantis in May 2009, was the last scheduled shuttle mission for HST. SM4 installed the replacement data-handling unit, repaired the ACS and STIS systems, installed improved nickel hydrogen batteries, and replaced other components including all six gyroscopes. SM4 also installed two new observation instruments—Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS)—and the Soft Capture and Rendezvous System, which will enable the future rendezvous, capture, and safe disposal of Hubble by either a crewed or robotic mission. Except for the ACS’s High Resolution Channel, which could not be repaired and was disabled, the work accomplished during SM4 rendered the telescope fully functional.

    Major projects

    Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey [CANDELS]

    The survey “aims to explore galactic evolution in the early Universe, and the very first seeds of cosmic structure at less than one billion years after the Big Bang.” The CANDELS project site describes the survey’s goals as the following:

    The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey is designed to document the first third of galactic evolution from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also find the first Type Ia SNe beyond z > 1.5 and establish their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected; each has multi-wavelength data from Spitzer and other facilities, and has extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to 109 solar masses out to z ~ 8.

    Frontier Fields program

    The program, officially named Hubble Deep Fields Initiative 2012, is aimed to advance the knowledge of early galaxy formation by studying high-redshift galaxies in blank fields with the help of gravitational lensing to see the “faintest galaxies in the distant universe”. The Frontier Fields web page describes the goals of the program being:

    To reveal hitherto inaccessible populations of z = 5–10 galaxies that are ten to fifty times fainter intrinsically than any presently known
    To solidify our understanding of the stellar masses and star formation histories of sub-L* galaxies at the earliest times
    To provide the first statistically meaningful morphological characterization of star forming galaxies at z > 5
    To find z > 8 galaxies stretched out enough by cluster lensing to discern internal structure and/or magnified enough by cluster lensing for spectroscopic follow-up.

    Cosmic Evolution Survey (COSMOS)

    The Cosmic Evolution Survey (COSMOS) is an astronomical survey designed to probe the formation and evolution of galaxies as a function of both cosmic time (redshift) and the local galaxy environment. The survey covers a two square degree equatorial field with spectroscopy and X-ray to radio imaging by most of the major space-based telescopes and a number of large ground based telescopes, making it a key focus region of extragalactic astrophysics. COSMOS was launched in 2006 as the largest project pursued by the Hubble Space Telescope at the time, and still is the largest continuous area of sky covered for the purposes of mapping deep space in blank fields, 2.5 times the area of the moon on the sky and 17 times larger than the largest of the CANDELS regions. The COSMOS scientific collaboration that was forged from the initial COSMOS survey is the largest and longest-running extragalactic collaboration, known for its collegiality and openness. The study of galaxies in their environment can be done only with large areas of the sky, larger than a half square degree. More than two million galaxies are detected, spanning 90% of the age of the Universe. The COSMOS collaboration is led by Caitlin Casey, Jeyhan Kartaltepe, and Vernesa Smolcic and involves more than 200 scientists in a dozen countries.

    Important discoveries

    Hubble has helped resolve some long-standing problems in astronomy, while also raising new questions. Some results have required new theories to explain them.

    Age of the universe

    Among its primary mission targets was to measure distances to Cepheid variable stars more accurately than ever before, and thus constrain the value of the Hubble constant, the measure of the rate at which the universe is expanding, which is also related to its age. Before the launch of HST, estimates of the Hubble constant typically had errors of up to 50%, but Hubble measurements of Cepheid variables in the Virgo Cluster and other distant galaxy clusters provided a measured value with an accuracy of ±10%, which is consistent with other more accurate measurements made since Hubble’s launch using other techniques. The estimated age is now about 13.7 billion years, but before the Hubble Telescope, scientists predicted an age ranging from 10 to 20 billion years.

    Expansion of the universe

    While Hubble helped to refine estimates of the age of the universe, it also cast doubt on theories about its future. Astronomers from the High-z Supernova Search Team and the Supernova Cosmology Project used ground-based telescopes and HST to observe distant supernovae and uncovered evidence that, far from decelerating under the influence of gravity, the expansion of the universe may in fact be accelerating. Three members of these two groups have subsequently been awarded Nobel Prizes for their discovery.

    Saul Perlmutter [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    The cause of this acceleration remains poorly understood; the most common cause attributed is Dark Energy.

    Black holes

    The high-resolution spectra and images provided by the HST have been especially well-suited to establishing the prevalence of black holes in the center of nearby galaxies. While it had been hypothesized in the early 1960s that black holes would be found at the centers of some galaxies, and astronomers in the 1980s identified a number of good black hole candidates, work conducted with Hubble shows that black holes are probably common to the centers of all galaxies. The Hubble programs further established that the masses of the nuclear black holes and properties of the galaxies are closely related. The legacy of the Hubble programs on black holes in galaxies is thus to demonstrate a deep connection between galaxies and their central black holes.

    Extending visible wavelength images

    A unique window on the Universe enabled by Hubble are the Hubble Deep Field, Hubble Ultra-Deep Field, and Hubble Extreme Deep Field images, which used Hubble’s unmatched sensitivity at visible wavelengths to create images of small patches of sky that are the deepest ever obtained at optical wavelengths. The images reveal galaxies billions of light years away, and have generated a wealth of scientific papers, providing a new window on the early Universe. The Wide Field Camera 3 improved the view of these fields in the infrared and ultraviolet, supporting the discovery of some of the most distant objects yet discovered, such as MACS0647-JD.

    The non-standard object SCP 06F6 was discovered by the Hubble Space Telescope in February 2006.

    On March 3, 2016, researchers using Hubble data announced the discovery of the farthest known galaxy to date: GN-z11. The Hubble observations occurred on February 11, 2015, and April 3, 2015, as part of the CANDELS/GOODS-North surveys.

    Solar System discoveries

    HST has also been used to study objects in the outer reaches of the Solar System, including the dwarf planets Pluto and Eris.

    The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 was fortuitously timed for astronomers, coming just a few months after Servicing Mission 1 had restored Hubble’s optical performance. Hubble images of the planet were sharper than any taken since the passage of Voyager 2 in 1979, and were crucial in studying the dynamics of the collision of a comet with Jupiter, an event believed to occur once every few centuries.

    During June and July 2012, U.S. astronomers using Hubble discovered Styx, a tiny fifth moon orbiting Pluto.

    In March 2015, researchers announced that measurements of aurorae around Ganymede, one of Jupiter’s moons, revealed that it has a subsurface ocean. Using Hubble to study the motion of its aurorae, the researchers determined that a large saltwater ocean was helping to suppress the interaction between Jupiter’s magnetic field and that of Ganymede. The ocean is estimated to be 100 km (60 mi) deep, trapped beneath a 150 km (90 mi) ice crust.

    From June to August 2015, Hubble was used to search for a Kuiper belt object (KBO) target for the New Horizons Kuiper Belt Extended Mission (KEM) when similar searches with ground telescopes failed to find a suitable target.

    This resulted in the discovery of at least five new KBOs, including the eventual KEM target, 486958 Arrokoth, that New Horizons performed a close fly-by of on January 1, 2019.

    In August 2020, taking advantage of a total lunar eclipse, astronomers using NASA’s Hubble Space Telescope have detected Earth’s own brand of sunscreen – ozone – in our atmosphere. This method simulates how astronomers and astrobiology researchers will search for evidence of life beyond Earth by observing potential “biosignatures” on exoplanets (planets around other stars).
    Hubble and ALMA image of MACS J1149.5+2223.

    Supernova reappearance

    On December 11, 2015, Hubble captured an image of the first-ever predicted reappearance of a supernova, dubbed “Refsdal”, which was calculated using different mass models of a galaxy cluster whose gravity is warping the supernova’s light. The supernova was previously seen in November 2014 behind galaxy cluster MACS J1149.5+2223 as part of Hubble’s Frontier Fields program. Astronomers spotted four separate images of the supernova in an arrangement known as an “Einstein Cross”.

    The light from the cluster has taken about five billion years to reach Earth, though the supernova exploded some 10 billion years ago. Based on early lens models, a fifth image was predicted to reappear by the end of 2015. The detection of Refsdal’s reappearance in December 2015 served as a unique opportunity for astronomers to test their models of how mass, especially dark matter, is distributed within this galaxy cluster.

    Impact on astronomy

    Many objective measures show the positive impact of Hubble data on astronomy. Over 15,000 papers based on Hubble data have been published in peer-reviewed journals, and countless more have appeared in conference proceedings. Looking at papers several years after their publication, about one-third of all astronomy papers have no citations, while only two percent of papers based on Hubble data have no citations. On average, a paper based on Hubble data receives about twice as many citations as papers based on non-Hubble data. Of the 200 papers published each year that receive the most citations, about 10% are based on Hubble data.

    Although the HST has clearly helped astronomical research, its financial cost has been large. A study on the relative astronomical benefits of different sizes of telescopes found that while papers based on HST data generate 15 times as many citations as a 4 m (13 ft) ground-based telescope such as the William Herschel Telescope, the HST costs about 100 times as much to build and maintain.

    Deciding between building ground- versus space-based telescopes is complex. Even before Hubble was launched, specialized ground-based techniques such as aperture masking interferometry had obtained higher-resolution optical and infrared images than Hubble would achieve, though restricted to targets about 108 times brighter than the faintest targets observed by Hubble. Since then, advances in “adaptive optics” have extended the high-resolution imaging capabilities of ground-based telescopes to the infrared imaging of faint objects.

    The usefulness of adaptive optics versus HST observations depends strongly on the particular details of the research questions being asked. In the visible bands, adaptive optics can correct only a relatively small field of view, whereas HST can conduct high-resolution optical imaging over a wide field. Only a small fraction of astronomical objects are accessible to high-resolution ground-based imaging; in contrast Hubble can perform high-resolution observations of any part of the night sky, and on objects that are extremely faint.

    Impact on aerospace engineering

    In addition to its scientific results, Hubble has also made significant contributions to aerospace engineering, in particular the performance of systems in low Earth orbit. These insights result from Hubble’s long lifetime on orbit, extensive instrumentation, and return of assemblies to the Earth where they can be studied in detail. In particular, Hubble has contributed to studies of the behavior of graphite composite structures in vacuum, optical contamination from residual gas and human servicing, radiation damage to electronics and sensors, and the long term behavior of multi-layer insulation. One lesson learned was that gyroscopes assembled using pressurized oxygen to deliver suspension fluid were prone to failure due to electric wire corrosion. Gyroscopes are now assembled using pressurized nitrogen. Another is that optical surfaces in LEO can have surprisingly long lifetimes; Hubble was only expected to last 15 years before the mirror became unusable, but after 14 years there was no measureable degradation. Finally, Hubble servicing missions, particularly those that serviced components not designed for in-space maintenance, have contributed towards the development of new tools and techniques for on-orbit repair.

    Archives

    All Hubble data is eventually made available via the Mikulski Archive for Space Telescopes at STScI, CADC and ESA/ESAC. Data is usually proprietary—available only to the principal investigator (PI) and astronomers designated by the PI—for twelve months after being taken. The PI can apply to the director of the STScI to extend or reduce the proprietary period in some circumstances.

    Observations made on Director’s Discretionary Time are exempt from the proprietary period, and are released to the public immediately. Calibration data such as flat fields and dark frames are also publicly available straight away. All data in the archive is in the FITS format, which is suitable for astronomical analysis but not for public use. The Hubble Heritage Project processes and releases to the public a small selection of the most striking images in JPEG and TIFF formats.

    Outreach activities

    It has always been important for the Space Telescope to capture the public’s imagination, given the considerable contribution of taxpayers to its construction and operational costs. After the difficult early years when the faulty mirror severely dented Hubble’s reputation with the public, the first servicing mission allowed its rehabilitation as the corrected optics produced numerous remarkable images.

    Several initiatives have helped to keep the public informed about Hubble activities. In the United States, outreach efforts are coordinated by the Space Telescope Science Institute (STScI) Office for Public Outreach, which was established in 2000 to ensure that U.S. taxpayers saw the benefits of their investment in the space telescope program. To that end, STScI operates the HubbleSite.org website. The Hubble Heritage Project, operating out of the STScI, provides the public with high-quality images of the most interesting and striking objects observed. The Heritage team is composed of amateur and professional astronomers, as well as people with backgrounds outside astronomy, and emphasizes the aesthetic nature of Hubble images. The Heritage Project is granted a small amount of time to observe objects which, for scientific reasons, may not have images taken at enough wavelengths to construct a full-color image.

    Since 1999, the leading Hubble outreach group in Europe has been the Hubble European Space Agency Information Centre (HEIC). This office was established at the Space Telescope European Coordinating Facility in Munich, Germany. HEIC’s mission is to fulfill HST outreach and education tasks for the European Space Agency. The work is centered on the production of news and photo releases that highlight interesting Hubble results and images. These are often European in origin, and so increase awareness of both ESA’s Hubble share (15%) and the contribution of European scientists to the observatory. ESA produces educational material, including a videocast series called Hubblecast designed to share world-class scientific news with the public.

    The Hubble Space Telescope has won two Space Achievement Awards from the Space Foundation, for its outreach activities, in 2001 and 2010.

    A replica of the Hubble Space Telescope is on the courthouse lawn in Marshfield, Missouri, the hometown of namesake Edwin P. Hubble.

    Major Instrumentation

    Hubble WFPC2 no longer in service.

    Wide Field Camera 3 [WFC3]

    Advanced Camera for Surveys [ACS]

    Cosmic Origins Spectrograph [COS]

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

    ESA50 Logo large

     
  • richardmitnick 10:27 pm on June 16, 2021 Permalink | Reply
    Tags: "How a supermassive black hole originates", , , , , , Fritz Zwicky and Vera Rubin, , ,   

    From UC Riverside (US) : “How a supermassive black hole originates” 

    UC Riverside bloc

    From UC Riverside (US)

    June 16, 2021
    Iqbal Pittalwala

    1
    Messier 87*. Credit:Event Horizon Telescope-EHT

    Supermassive black holes, or SMBHs, are black holes with masses that are several million to billion times the mass of our sun. The Milky Way hosts an SMBH with mass a few million times the solar mass. Surprisingly, astrophysical observations show that SMBHs already existed when the universe was very young. For example, a billion solar mass black holes are found when the universe was just 6% of its current age, 13.7 billion years. How do these SMBHs in the early universe originate?

    A team led by a theoretical physicist at the University of California, Riverside, has come up with an explanation: a massive seed black hole that the collapse of a dark matter halo could produce.

    Dark matter halo is the halo of invisible matter surrounding a galaxy or a cluster of galaxies.

    Although Dark Matter has never been detected in laboratories, physicists remain confident this mysterious matter that makes up 85% of the universe’s matter exists. Were the visible matter of a galaxy not embedded in a dark matter halo, this matter would fly apart.

    “Physicists are puzzled why SMBHs in the early universe, which are located in the central regions of dark matter halos, grow so massively in a short time,” said Hai-Bo Yu, an associate professor of physics and astronomy at UC Riverside, who led the study that appears in The Astrophysical Journal Letters. “It’s like a 5-year-old child that weighs, say, 200 pounds. Such a child would astonish us all because we know the typical weight of a newborn baby and how fast this baby can grow. Where it comes to black holes, physicists have general expectations about the mass of a seed black hole and its growth rate. The presence of SMBHs suggests these general expectations have been violated, requiring new knowledge. And that’s exciting.”

    A seed black hole is a black hole at its initial stage — akin to the baby stage in the life of a human.

    “We can think of two reasons,” Yu added. “The seed — or ‘baby’ — black hole is either much more massive or it grows much faster than we thought, or both. The question that then arises is what are the physical mechanisms for producing a massive enough seed black hole or achieving a fast enough growth rate?”

    “It takes time for black holes to grow massive by accreting surrounding matter,” said co-author Yi-Ming Zhong, a postdoctoral researcher at the Kavli Institute for Cosmological Physics at the University of Chicago. “Our paper shows that if dark matter has self-interactions then the gravothermal collapse of a halo can lead to a massive enough seed black hole. Its growth rate would be more consistent with general expectations.”

    In astrophysics, a popular mechanism used to explain SMBHs is the collapse of pristine gas in protogalaxies in the early universe.

    “This mechanism, however, cannot produce a massive enough seed black hole to accommodate newly observed SMBHs — unless the seed black hole experienced an extremely fast growth rate,” Yu said. “Our work provides an alternative explanation: a self-interacting dark matter halo experiences gravothermal instability and its central region collapses into a seed black hole.”

    The explanation Yu and his colleagues propose works in the following way:

    Dark matter particles first cluster together under the influence of gravity and form a dark matter halo. During the evolution of the halo, two competing forces — gravity and pressure — operate. While gravity pulls dark matter particles inward, pressure pushes them outward. If dark matter particles have no self-interactions, then, as gravity pulls them toward the central halo, they become hotter, that is, they move faster, the pressure increases effectively, and they bounce back. However, in the case of self-interacting dark matter, dark matter self-interactions can transport the heat from those “hotter” particles to nearby colder ones. This makes it difficult for the dark matter particles to bounce back.

    Yu explained that the central halo, which would collapse into a black hole, has angular momentum, meaning, it rotates. The self-interactions can induce viscosity, or “friction,” that dissipates the angular momentum. During the collapse process, the central halo, which has a fixed mass, shrinks in radius and slows down in rotation due to viscosity. As the evolution continues, the central halo eventually collapses into a singular state: a seed black hole. This seed can grow more massive by accreting surrounding baryonic — or visible — matter such as gas and stars.

    “The advantage of our scenario is that the mass of the seed black hole can be high since it is produced by the collapse of a dark matter halo,” Yu said. “Thus, it can grow into a supermassive black hole in a relatively short timescale.”

    The new work is novel in that the researchers identify the importance of baryons—ordinary atomic and molecular particles — for this idea to work.

    “First, we show the presence of baryons, such as gas and stars, can significantly speed up the onset of the gravothermal collapse of a halo and a seed black hole could be created early enough,” said Wei-Xiang Feng, Yu’s graduate student and a co-author on the paper. “Second, we show the self-interactions can induce viscosity that dissipates the angular momentum remnant of the central halo. Third, we develop a method to examine the condition for triggering general relativistic instability of the collapsed halo, which ensures a seed black hole could form if the condition is satisfied.”

    Over the past decade, Yu has explored novel predictions of dark matter self-interactions and their observational consequences. His work [Physical Review Letters] has shown that self-interacting dark matter can provide a good explanation for the observed motion of stars and gas in galaxies.

    “In many galaxies, stars and gas dominate their central regions,” he said. “Thus, it’s natural to ask how the presence of this baryonic matter affects the collapse process. We show it will speed up the onset of the collapse. This feature is exactly what we need to explain the origin of supermassive black holes in the early universe. The self-interactions also lead to viscosity that can dissipate angular momentum of the central halo and further help the collapse process.”

    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    _____________________________________________________________________________________

    The study was funded by the Department of Energy (US); National Aeronautics Space Agency (US); the Kavli Institute for Cosmological Physics (US); and the John Templeton Foundation.

    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 Riverside Campus

    The University of California, Riverside (US) is a public land-grant research university in Riverside, California. It is one of the 10 campuses of the University of California (US) system. The main campus sits on 1,900 acres (769 ha) in a suburban district of Riverside with a branch campus of 20 acres (8 ha) in Palm Desert. In 1907, the predecessor to UC Riverside was founded as the UC Citrus Experiment Station, Riverside which pioneered research in biological pest control and the use of growth regulators responsible for extending the citrus growing season in California from four to nine months. Some of the world’s most important research collections on citrus diversity and entomology, as well as science fiction and photography, are located at Riverside.

    UC Riverside’s undergraduate College of Letters and Science opened in 1954. The Regents of the University of California declared UC Riverside a general campus of the system in 1959, and graduate students were admitted in 1961. To accommodate an enrollment of 21,000 students by 2015, more than $730 million has been invested in new construction projects since 1999. Preliminary accreditation of the UC Riverside School of Medicine was granted in October 2012 and the first class of 50 students was enrolled in August 2013. It is the first new research-based public medical school in 40 years.

    UC Riverside is classified among “R1: Doctoral Universities – Very high research activity.” The 2019 U.S. News & World Report Best Colleges rankings places UC Riverside tied for 35th among top public universities and ranks 85th nationwide. Over 27 of UC Riverside’s academic programs, including the Graduate School of Education and the Bourns College of Engineering, are highly ranked nationally based on peer assessment, student selectivity, financial resources, and other factors. Washington Monthly ranked UC Riverside 2nd in the United States in terms of social mobility, research and community service, while U.S. News ranks UC Riverside as the fifth most ethnically diverse and, by the number of undergraduates receiving Pell Grants (42 percent), the 15th most economically diverse student body in the nation. Over 70% of all UC Riverside students graduate within six years without regard to economic disparity. UC Riverside’s extensive outreach and retention programs have contributed to its reputation as a “university of choice” for minority students. In 2005, UCR became the first public university campus in the nation to offer a gender-neutral housing option.UC Riverside’s sports teams are known as the Highlanders and play in the Big West Conference of the National Collegiate Athletic Association (NCAA) Division I. Their nickname was inspired by the high altitude of the campus, which lies on the foothills of Box Springs Mountain. The UC Riverside women’s basketball team won back-to-back Big West championships in 2006 and 2007. In 2007, the men’s baseball team won its first conference championship and advanced to the regionals for the second time since the university moved to Division I in 2001.

    History

    At the turn of the 20th century, Southern California was a major producer of citrus, the region’s primary agricultural export. The industry developed from the country’s first navel orange trees, planted in Riverside in 1873. Lobbied by the citrus industry, the UC Regents established the UC Citrus Experiment Station (CES) on February 14, 1907, on 23 acres (9 ha) of land on the east slope of Mount Rubidoux in Riverside. The station conducted experiments in fertilization, irrigation and crop improvement. In 1917, the station was moved to a larger site, 475 acres (192 ha) near Box Springs Mountain.

    The 1944 passage of the GI Bill during World War II set in motion a rise in college enrollments that necessitated an expansion of the state university system in California. A local group of citrus growers and civic leaders, including many UC Berkeley(US) alumni, lobbied aggressively for a UC-administered liberal arts college next to the CES. State Senator Nelson S. Dilworth authored Senate Bill 512 (1949) which former Assemblyman Philip L. Boyd and Assemblyman John Babbage (both of Riverside) were instrumental in shepherding through the State Legislature. Governor Earl Warren signed the bill in 1949, allocating $2 million for initial campus construction.

    Gordon S. Watkins, dean of the College of Letters and Science at University of California at Los Angeles(US), became the first provost of the new college at Riverside. Initially conceived of as a small college devoted to the liberal arts, he ordered the campus built for a maximum of 1,500 students and recruited many young junior faculty to fill teaching positions. He presided at its opening with 65 faculty and 127 students on February 14, 1954, remarking, “Never have so few been taught by so many.”

    UC Riverside’s enrollment exceeded 1,000 students by the time Clark Kerr became president of the University of California(US) system in 1958. Anticipating a “tidal wave” in enrollment growth required by the baby boom generation, Kerr developed the California Master Plan for Higher Education and the Regents designated Riverside a general university campus in 1959. UC Riverside’s first chancellor, Herman Theodore Spieth, oversaw the beginnings of the school’s transition to a full university and its expansion to a capacity of 5,000 students. UC Riverside’s second chancellor, Ivan Hinderaker led the campus through the era of the free speech movement and kept student protests peaceful in Riverside. According to a 1998 interview with Hinderaker, the city of Riverside received negative press coverage for smog after the mayor asked Governor Ronald Reagan to declare the South Coast Air Basin a disaster area in 1971; subsequent student enrollment declined by up to 25% through 1979. Hinderaker’s development of innovative programs in business administration and biomedical sciences created incentive for enough students to enroll at Riverside to keep the campus open.

    In the 1990s, the UC Riverside experienced a new surge of enrollment applications, now known as “Tidal Wave II”. The Regents targeted UC Riverside for an annual growth rate of 6.3%, the fastest in the UC system, and anticipated 19,900 students at UC Riverside by 2010. By 1995, African American, American Indian, and Latino student enrollments accounted for 30% of the UC Riverside student body, the highest proportion of any UC campus at the time. The 1997 implementation of Proposition 209—which banned the use of affirmative action by state agencies—reduced the ethnic diversity at the more selective UC campuses but further increased it at UC Riverside.

    With UC Riverside scheduled for dramatic population growth, efforts have been made to increase its popular and academic recognition. The students voted for a fee increase to move UC Riverside athletics into NCAA Division I standing in 1998. In the 1990s, proposals were made to establish a law school, a medical school, and a school of public policy at UC Riverside, with the UC Riverside School of Medicine and the School of Public Policy becoming reality in 2012. In June 2006, UC Riverside received its largest gift, 15.5 million from two local couples, in trust towards building its medical school. The Regents formally approved UC Riverside’s medical school proposal in 2006. Upon its completion in 2013, it was the first new medical school built in California in 40 years.

    Academics

    As a campus of the University of California(US) system, UC Riverside is governed by a Board of Regents and administered by a president. The current president is Michael V. Drake, and the current chancellor of the university is Kim A. Wilcox. UC Riverside’s academic policies are set by its Academic Senate, a legislative body composed of all UC Riverside faculty members.

    UC Riverside is organized into three academic colleges, two professional schools, and two graduate schools. UC Riverside’s liberal arts college, the College of Humanities, Arts and Social Sciences, was founded in 1954, and began accepting graduate students in 1960. The College of Natural and Agricultural Sciences, founded in 1960, incorporated the CES as part of the first research-oriented institution at UC Riverside; it eventually also incorporated the natural science departments formerly associated with the liberal arts college to form its present structure in 1974. UC Riverside’s newest academic unit, the Bourns College of Engineering, was founded in 1989. Comprising the professional schools are the Graduate School of Education, founded in 1968, and the UCR School of Business, founded in 1970. These units collectively provide 81 majors and 52 minors, 48 master’s degree programs, and 42 Doctor of Philosophy (PhD) programs. UC Riverside is the only UC campus to offer undergraduate degrees in creative writing and public policy and one of three UCs (along with University of California-Berkeley (US) and University of California-Irvine (US)) to offer an undergraduate degree in business administration. Through its Division of Biomedical Sciences, founded in 1974, UC Riverside offers the Thomas Haider medical degree program in collaboration with University of California-Los Angeles(US). UC Riverside’s doctoral program in the emerging field of dance theory, founded in 1992, was the first program of its kind in the United States, and UC Riverside’s minor in lesbian, gay and bisexual studies, established in 1996, was the first undergraduate program of its kind in the UC system. A new BA program in bagpipes was inaugurated in 2007.

    Research and economic impact

    UC Riverside operated under a $727 million budget in fiscal year 2014–15. The state government provided $214 million, student fees accounted for $224 million and $100 million came from contracts and grants. Private support and other sources accounted for the remaining $189 million. Overall, monies spent at UC Riverside have an economic impact of nearly $1 billion in California. UC Riverside research expenditure in FY 2018 totaled $167.8 million. Total research expenditures at UC Riverside are significantly concentrated in agricultural science, accounting for 53% of total research expenditures spent by the university in 2002. Top research centers by expenditure, as measured in 2002, include the Agricultural Experiment Station; the Center for Environmental Research and Technology; the Center for Bibliographical Studies; the Air Pollution Research Center; and the Institute of Geophysics and Planetary Physics.

    Throughout UC Riverside’s history, researchers have developed more than 40 new citrus varieties and invented new techniques to help the $960 million-a-year California citrus industry fight pests and diseases. In 1927, entomologists at the CES introduced two wasps from Australia as natural enemies of a major citrus pest, the citrophilus mealybug, saving growers in Orange County $1 million in annual losses. This event was pivotal in establishing biological control as a practical means of reducing pest populations. In 1963, plant physiologist Charles Coggins proved that application of gibberellic acid allows fruit to remain on citrus trees for extended periods. The ultimate result of his work, which continued through the 1980s, was the extension of the citrus-growing season in California from four to nine months. In 1980, UC Riverside released the Oroblanco grapefruit, its first patented citrus variety. Since then, the citrus breeding program has released other varieties such as the Melogold grapefruit, the Gold Nugget mandarin (or tangerine), and others that have yet to be given trademark names.

    To assist entrepreneurs in developing new products, UC Riverside is a primary partner in the Riverside Regional Technology Park, which includes the City of Riverside and the County of Riverside. It also administers six reserves of the University of California Natural Reserve System. UC Riverside recently announced a partnership with China Agricultural University[中国农业大学](CN) to launch a new center in Beijing, which will study ways to respond to the country’s growing environmental issues. UC Riverside can also boast the birthplace of two name reactions in organic chemistry, the Castro-Stephens coupling and the Midland Alpine Borane Reduction.

     
  • richardmitnick 8:41 pm on June 14, 2021 Permalink | Reply
    Tags: "Dark matter is slowing the spin of the Milky Way’s galactic bar", , , , , , , Dark Matter Backround, Fritz Zwicky and Vera Rubin, ,   

    From University College London (UK) and From University of Oxford (UK): “Dark matter is slowing the spin of the Milky Way’s galactic bar” 

    UCL bloc

    From University College London (UK)

    and

    U Oxford bloc

    From University of Oxford (UK)

    14 June 2021

    Mark Greaves
    +44 (0)7990 675947
    m.greaves@ucl.ac.uk

    The spin of the Milky Way’s galactic bar, which is made up of billions of clustered stars, has slowed by about a quarter since its formation, according to a new study by University College London (UK) and University of Oxford (UK) researchers.

    For 30 years, astrophysicists have predicted such a slowdown, but this is the first time it has been measured.

    The researchers say it gives a new type of insight into the nature of Dark Matter, which acts like a counterweight slowing the spin.

    In the study, published in the MNRAS, researchers analysed Gaia space telescope observations of a large group of stars, the Hercules stream, which are in resonance with the bar – that is, they revolve around the galaxy at the same rate as the bar’s spin.

    These stars are gravitationally trapped by the spinning bar. The same phenomenon occurs with Jupiter’s Trojan and Greek asteroids, which orbit Jupiter’s Lagrange points (ahead and behind Jupiter). If the bar’s spin slows down, these stars would be expected to move further out in the galaxy, keeping their orbital period matched to that of the bar’s spin.

    The researchers found that the stars in the stream carry a chemical fingerprint – they are richer in heavier elements (called metals in astronomy), proving that they have travelled away from the galactic centre, where stars and star-forming gas are about 10 times as rich in metals compared to the outer galaxy.

    Using this data, the team inferred that the bar – made up of billions of stars and trillions of solar masses – had slowed down its spin by at least 24% since it first formed.

    Co-author Dr Ralph Schoenrich (UCL Physics & Astronomy) said: “Astrophysicists have long suspected that the spinning bar at the centre of our galaxy is slowing down, but we have found the first evidence of this happening.

    “The counterweight slowing this spin must be dark matter. Until now, we have only been able to infer dark matter by mapping the gravitational potential of galaxies and subtracting the contribution from visible matter.

    “Our research provides a new type of measurement of dark matter – not of its gravitational energy, but of its inertial mass (the dynamical response), which slows the bar’s spin.”

    Co-author and PhD student Rimpei Chiba, of the University of Oxford, said: “Our finding offers a fascinating perspective for constraining the nature of dark matter, as different models will change this inertial pull on the galactic bar.

    “Our finding also poses a major problem for alternative gravity theories – as they lack dark matter in the halo, they predict no, or significantly too little slowing of the bar.”

    The Milky Way, like other galaxies, is thought to be embedded in a ‘halo’ of dark matter that extends well beyond its visible edge.

    Dark matter is invisible and its nature is unknown, but its existence is inferred from galaxies behaving as if they were shrouded in significantly more mass than we can see. There is thought to be about five times as much dark matter in the Universe as ordinary, visible matter.

    Alternative gravity theories such as modified Newtonian dynamics reject the idea of dark matter, instead seeking to explain discrepancies by tweaking Einstein’s theory of general relativity.

    The Milky Way is a barred spiral galaxy, with a thick bar of stars in the middle and spiral arms extending through the disc outside the bar. The bar rotates in the same direction as the galaxy.

    The research received support from the Royal Society, the Takenaka Scholarship Foundation, and the Science and Technology Facilities Council (STFC).

    ______________________________________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970

    Dark Matter Research

    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington. Axion Dark Matter Experiment

    _____________________________________________________________________________________

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Oxford campus

    University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the world’s second-oldest university in continuous operation. It grew rapidly from 1167 when Henry II banned English students from attending the University of Paris [Université de Paris](FR). After disputes between students and Oxford townsfolk in 1209, some academics fled north-east to Cambridge where they established what became the University of Cambridge (UK). The two English ancient universities share many common features and are jointly referred to as Oxbridge.

    The university is made up of thirty-nine semi-autonomous constituent colleges, six permanent private halls, and a range of academic departments which are organised into four divisions. All the colleges are self-governing institutions within the university, each controlling its own membership and with its own internal structure and activities. All students are members of a college. It does not have a main campus, and its buildings and facilities are scattered throughout the city centre. Undergraduate teaching at Oxford consists of lectures, small-group tutorials at the colleges and halls, seminars, laboratory work and occasionally further tutorials provided by the central university faculties and departments. Postgraduate teaching is provided predominantly centrally.

    Oxford operates the world’s oldest university museum, as well as the largest university press in the world and the largest academic library system nationwide. In the fiscal year ending 31 July 2019, the university had a total income of £2.45 billion, of which £624.8 million was from research grants and contracts.

    Oxford has educated a wide range of notable alumni, including 28 prime ministers of the United Kingdom and many heads of state and government around the world. As of October 2020, 72 Nobel Prize laureates, 3 Fields Medalists, and 6 Turing Award winners have studied, worked, or held visiting fellowships at the University of Oxford, while its alumni have won 160 Olympic medals. Oxford is the home of numerous scholarships, including the Rhodes Scholarship, one of the oldest international graduate scholarship programmes.

    To be a member of the university, all students, and most academic staff, must also be a member of a college or hall. There are thirty-nine colleges of the University of Oxford (including Reuben College, planned to admit students in 2021) and six permanent private halls (PPHs), each controlling its membership and with its own internal structure and activities. Not all colleges offer all courses, but they generally cover a broad range of subjects.

    The colleges are:

    All-Souls College
    Balliol College
    Brasenose College
    Christ Church College
    Corpus-Christi College
    Exeter College
    Green-Templeton College
    Harris-Manchester College
    Hertford College
    Jesus College
    Keble College
    Kellogg College
    Lady-Margaret-Hall
    Linacre College
    Lincoln College
    Magdalen College
    Mansfield College
    Merton College
    New College
    Nuffield College
    Oriel College
    Pembroke College
    Queens College
    Reuben College
    St-Anne’s College
    St-Antony’s College
    St-Catherines College
    St-Cross College
    St-Edmund-Hall College
    St-Hilda’s College
    St-Hughs College
    St-John’s College
    St-Peters College
    Somerville College
    Trinity College
    University College

    UCL campus

    Established in 1826, as London University by founders inspired by the radical ideas of Jeremy Bentham, University College London (UK) was the first university institution to be established in London, and the first in England to be entirely secular and to admit students regardless of their religion. University College London (UK) also makes contested claims to being the third-oldest university in England and the first to admit women. In 1836, University College London (UK) became one of the two founding colleges of the University of London, which was granted a royal charter in the same year. It has grown through mergers, including with the Institute of Ophthalmology (in 1995); the Institute of Neurology (in 1997); the Royal Free Hospital Medical School (in 1998); the Eastman Dental Institute (in 1999); the School of Slavonic and East European Studies (in 1999); the School of Pharmacy (in 2012) and the Institute of Education (in 2014).

    University College London (UK) has its main campus in the Bloomsbury area of central London, with a number of institutes and teaching hospitals elsewhere in central London and satellite campuses in Queen Elizabeth Olympic Park in Stratford, east London and in Doha, Qatar. University College London (UK) is organised into 11 constituent faculties, within which there are over 100 departments, institutes and research centres. University College London (UK) operates several museums and collections in a wide range of fields, including the Petrie Museum of Egyptian Archaeology and the Grant Museum of Zoology and Comparative Anatomy, and administers the annual Orwell Prize in political writing. In 2019/20, UCL had around 43,840 students and 16,400 staff (including around 7,100 academic staff and 840 professors) and had a total income of £1.54 billion, of which £468 million was from research grants and contracts.

    University College London (UK) is a member of numerous academic organisations, including the Russell Group(UK) and the League of European Research Universities, and is part of UCL Partners, the world’s largest academic health science centre, and is considered part of the “golden triangle” of elite, research-intensive universities in England.

    University College London (UK) has many notable alumni, including the respective “Fathers of the Nation” of India; Kenya and Mauritius; the founders of Ghana; modern Japan; Nigeria; the inventor of the telephone; and one of the co-discoverers of the structure of DNA. UCL academics discovered five of the naturally occurring noble gases; discovered hormones; invented the vacuum tube; and made several foundational advances in modern statistics. As of 2020, 34 Nobel Prize winners and 3 Fields medalists have been affiliated with UCL as alumni, faculty or researchers.

    History

    University College London (UK) was founded on 11 February 1826 under the name London University, as an alternative to the Anglican universities of the University of Oxford(UK) and University of Cambridge(UK). London University’s first Warden was Leonard Horner, who was the first scientist to head a British university.

    Despite the commonly held belief that the philosopher Jeremy Bentham was the founder of University College London (UK), his direct involvement was limited to the purchase of share No. 633, at a cost of £100 paid in nine installments between December 1826 and January 1830. In 1828 he did nominate a friend to sit on the council, and in 1827 attempted to have his disciple John Bowring appointed as the first professor of English or History, but on both occasions his candidates were unsuccessful. This suggests that while his ideas may have been influential, he himself was less so. However, Bentham is today commonly regarded as the “spiritual father” of University College London (UK), as his radical ideas on education and society were the inspiration to the institution’s founders, particularly the Scotsmen James Mill (1773–1836) and Henry Brougham (1778–1868).

    In 1827, the Chair of Political Economy at London University was created, with John Ramsay McCulloch as the first incumbent, establishing one of the first departments of economics in England. In 1828 the university became the first in England to offer English as a subject and the teaching of Classics and medicine began. In 1830, London University founded the London University School, which would later become University College School. In 1833, the university appointed Alexander Maconochie, Secretary to the Royal Geographical Society, as the first professor of geography in the British Isles. In 1834, University College Hospital (originally North London Hospital) opened as a teaching hospital for the university’s medical school.

    1836 to 1900 – University College, London

    In 1836, London University was incorporated by royal charter under the name University College, London. On the same day, the University of London was created by royal charter as a degree-awarding examining board for students from affiliated schools and colleges, with University College and King’s College, London being named in the charter as the first two affiliates.[23]

    The Slade School of Fine Art was founded as part of University College in 1871, following a bequest from Felix Slade.

    In 1878, the University College London (UK) gained a supplemental charter making it the first British university to be allowed to award degrees to women. The same year University College London (UK) admitted women to the faculties of Arts and Law and of Science, although women remained barred from the faculties of Engineering and of Medicine (with the exception of courses on public health and hygiene). While University College London (UK) claims to have been the first university in England to admit women on equal terms to men, from 1878, the University of Bristol(UK) also makes this claim, having admitted women from its foundation (as a college) in 1876. Armstrong College, a predecessor institution of Newcastle University (UK), also allowed women to enter from its foundation in 1871, although none actually enrolled until 1881. Women were finally admitted to medical studies during the First World War in 1917, although limitations were placed on their numbers after the war ended.

    In 1898, Sir William Ramsay discovered the elements krypton; neon; and xenon whilst professor of chemistry at University College London (UK).

    1900 to 1976 – University of London, University College

    In 1900, the University College London (UK) was reconstituted as a federal university with new statutes drawn up under the University of London Act 1898. UCL, along with a number of other colleges in London, became a school of the University of London. While most of the constituent institutions retained their autonomy, University College London (UK) was merged into the University in 1907 under the University College London (Transfer) Act 1905 and lost its legal independence. Its formal name became University College London (UK), University College, although for most informal and external purposes the name “University College, London” (or the initialism UCL) was still used.

    1900 also saw the decision to appoint a salaried head of the college. The first incumbent was Carey Foster, who served as Principal (as the post was originally titled) from 1900 to 1904. He was succeeded by Gregory Foster (no relation), and in 1906 the title was changed to Provost to avoid confusion with the Principal of the University of London. Gregory Foster remained in post until 1929. In 1906, the Cruciform Building was opened as the new home for University College Hospital.

    As it acknowledged and apologized for in 2021, University College London (UK) played “a fundamental role in the development, propagation and legitimisation of eugenics” during the first half of the 20th century. Among the prominent eugenicists who taught at University College London (UK) were Francis Galton, who coined the term “eugenics”, and Karl Pearson, and eugenics conferences were held at UCL until 2017.

    University College London (UK) sustained considerable bomb damage during the Second World War, including the complete destruction of the Great Hall and the Carey Foster Physics Laboratory. Fires gutted the library and destroyed much of the main building, including the dome. The departments were dispersed across the country to Aberystwyth; Bangor; Gwynedd; University of Cambridge (UK) ; University of Oxford (UK); Rothamsted near Harpenden; Hertfordshire; and Sheffield, with the administration at Stanstead Bury near Ware, Hertfordshire. The first UCL student magazine, Pi, was published for the first time on 21 February 1946. The Institute of Jewish Studies relocated to UCL in 1959.

    The Mullard Space Science Laboratory(UK) was established in 1967. In 1973, UCL became the first international node to the precursor of the internet, the ARPANET.

    Although University College London (UK) was among the first universities to admit women on the same terms as men, in 1878, the college’s senior common room, the Housman Room, remained men-only until 1969. After two unsuccessful attempts, a motion was passed that ended segregation by sex at University College London (UK). This was achieved by Brian Woledge (Fielden Professor of French at University College London (UK) from 1939 to 1971) and David Colquhoun, at that time a young lecturer in pharmacology.

    1976 to 2005 – University College London (UK)

    In 1976, a new charter restored University College London (UK) ‘s legal independence, although still without the power to award its own degrees. Under this charter the college became formally known as University College London (UK). This name abandoned the comma used in its earlier name of “University College, London”.

    In 1986, University College London (UK) merged with the Institute of Archaeology. In 1988, University College London (UK) merged with the Institute of Laryngology & Otology; the Institute of Orthopaedics; the Institute of Urology & Nephrology; and Middlesex Hospital Medical School.

    In 1993, a reorganisation of the University of London (UK) meant that University College London (UK) and other colleges gained direct access to government funding and the right to confer University of London degrees themselves. This led to University College London (UK) being regarded as a de facto university in its own right.

    In 1994, the University College London (UK) Hospitals NHS Trust was established. University College London (UK) merged with the College of Speech Sciences and the Institute of Ophthalmology in 1995; the Institute of Child Health and the School of Podiatry in 1996; and the Institute of Neurology in 1997. In 1998, UCL merged with the Royal Free Hospital Medical School to create the Royal Free and University College Medical School (renamed the University College London (UK) Medical School in October 2008). In 1999, UCL merged with the School of Slavonic and East European Studies and the Eastman Dental Institute.

    The University College London (UK) Jill Dando Institute of Crime Science, the first university department in the world devoted specifically to reducing crime, was founded in 2001.

    Proposals for a merger between University College London (UK) and Imperial College London(UK) were announced in 2002. The proposal provoked strong opposition from University College London (UK) teaching staff and students and the AUT union, which criticised “the indecent haste and lack of consultation”, leading to its abandonment by University College London (UK) provost Sir Derek Roberts. The blogs that helped to stop the merger are preserved, though some of the links are now broken: see David Colquhoun’s blog and the Save University College London (UK) blog, which was run by David Conway, a postgraduate student in the department of Hebrew and Jewish studies.

    The London Centre for Nanotechnology was established in 2003 as a joint venture between University College London (UK) and Imperial College London (UK). They were later joined by King’s College London(UK) in 2018.

    Since 2003, when University College London (UK) professor David Latchman became master of the neighbouring Birkbeck, he has forged closer relations between these two University of London colleges, and personally maintains departments at both. Joint research centres include the UCL/Birkbeck Institute for Earth and Planetary Sciences; the University College London (UK) /Birkbeck/IoE Centre for Educational Neuroscience; the University College London (UK) /Birkbeck Institute of Structural and Molecular Biology; and the Birkbeck- University College London (UK) Centre for Neuroimaging.

    2005 to 2010

    In 2005, University College London (UK) was finally granted its own taught and research degree awarding powers and all University College London (UK) students registered from 2007/08 qualified with University College London (UK) degrees. Also in 2005, University College London (UK) adopted a new corporate branding under which the name University College London (UK) was replaced by the initialism UCL in all external communications. In the same year, a major new £422 million building was opened for University College Hospital on Euston Road, the University College London (UK) Ear Institute was established and a new building for the University College London (UK) School of Slavonic and East European Studies was opened.

    In 2007, the University College London (UK) Cancer Institute was opened in the newly constructed Paul O’Gorman Building. In August 2008, University College London (UK) formed UCL Partners, an academic health science centre, with Great Ormond Street Hospital for Children NHS Trust; Moorfields Eye Hospital NHS Foundation Trust; Royal Free London NHS Foundation Trust; and University College London Hospitals NHS Foundation Trust. In 2008, University College London (UK) established the University College London (UK) School of Energy & Resources in Adelaide, Australia, the first campus of a British university in the country. The School was based in the historic Torrens Building in Victoria Square and its creation followed negotiations between University College London (UK) Vice Provost Michael Worton and South Australian Premier Mike Rann.

    In 2009, the Yale UCL Collaborative was established between University College London (UK); UCL Partners; Yale University(US); Yale School of Medicine; and Yale – New Haven Hospital. It is the largest collaboration in the history of either university, and its scope has subsequently been extended to the humanities and social sciences.

    2010 to 2015

    In June 2011, the mining company BHP Billiton agreed to donate AU$10 million to University College London (UK) to fund the establishment of two energy institutes – the Energy Policy Institute; based in Adelaide, and the Institute for Sustainable Resources, based in London.

    In November 2011, University College London (UK) announced plans for a £500 million investment in its main Bloomsbury campus over 10 years, as well as the establishment of a new 23-acre campus next to the Olympic Park in Stratford in the East End of London. It revised its plans of expansion in East London and in December 2014 announced to build a campus (UCL East) covering 11 acres and provide up to 125,000m^2 of space on Queen Elizabeth Olympic Park. UCL East will be part of plans to transform the Olympic Park into a cultural and innovation hub, where University College London (UK) will open its first school of design, a centre of experimental engineering and a museum of the future, along with a living space for students.

    The School of Pharmacy, University of London merged with University College London (UK) on 1 January 2012, becoming the University College London (UK) School of Pharmacy within the Faculty of Life Sciences. In May 2012, University College London (UK), Imperial College London and the semiconductor company Intel announced the establishment of the Intel Collaborative Research Institute for Sustainable Connected Cities, a London-based institute for research into the future of cities.

    In August 2012, University College London (UK) received criticism for advertising an unpaid research position; it subsequently withdrew the advert.

    University College London (UK) and the Institute of Education formed a strategic alliance in October 2012, including co-operation in teaching, research and the development of the London schools system. In February 2014, the two institutions announced their intention to merge, and the merger was completed in December 2014.

    In September 2013, a new Department of Science, Technology, Engineering and Public Policy (STEaPP) was established within the Faculty of Engineering, one of several initiatives within the university to increase and reflect upon the links between research and public sector decision-making.

    In October 2013, it was announced that the Translation Studies Unit of Imperial College London would move to University College London (UK), becoming part of the University College London (UK) School of European Languages, Culture and Society. In December 2013, it was announced that University College London (UK) and the academic publishing company Elsevier would collaborate to establish the UCL Big Data Institute. In January 2015, it was announced that University College London (UK) had been selected by the UK government as one of the five founding members of the Alan Turing Institute(UK) (together with the universities of Cambridge, University of Edinburgh(SCL), Oxford and University of Warwick(UK)), an institute to be established at the British Library to promote the development and use of advanced mathematics, computer science, algorithms and big data.

    2015 to 2020

    In August 2015, the Department of Management Science and Innovation was renamed as the School of Management and plans were announced to greatly expand University College London (UK) ‘s activities in the area of business-related teaching and research. The school moved from the Bloomsbury campus to One Canada Square in Canary Wharf in 2016.

    University College London (UK) established the Institute of Advanced Studies (IAS) in 2015 to promote interdisciplinary research in humanities and social sciences. The prestigious annual Orwell Prize for political writing moved to the IAS in 2016.

    In June 2016 it was reported in Times Higher Education that as a result of administrative errors hundreds of students who studied at the UCL Eastman Dental Institute between 2005–06 and 2013–14 had been given the wrong marks, leading to an unknown number of students being attributed with the wrong qualifications and, in some cases, being failed when they should have passed their degrees. A report by University College London (UK) ‘s Academic Committee Review Panel noted that, according to the institute’s own review findings, senior members of University College London (UK) staff had been aware of issues affecting students’ results but had not taken action to address them. The Review Panel concluded that there had been an apparent lack of ownership of these matters amongst the institute’s senior staff.

    In December 2016 it was announced that University College London (UK) would be the hub institution for a new £250 million national dementia research institute, to be funded with £150 million from the Medical Research Council and £50 million each from Alzheimer’s Research UK and the Alzheimer’s Society.

    In May 2017 it was reported that staff morale was at “an all time low”, with 68% of members of the academic board who responded to a survey disagreeing with the statement ” University College London (UK) is well managed” and 86% with “the teaching facilities are adequate for the number of students”. Michael Arthur, the Provost and President, linked the results to the “major change programme” at University College London (UK). He admitted that facilities were under pressure following growth over the past decade, but said that the issues were being addressed through the development of UCL East and rental of other additional space.

    In October 2017 University College London (UK) ‘s council voted to apply for university status while remaining part of the University of London. University College London (UK) ‘s application to become a university was subject to Parliament passing a bill to amend the statutes of the University of London, which received royal assent on 20 December 2018.

    The University College London (UK) Adelaide satellite campus closed in December 2017, with academic staff and student transferring to the University of South Australia(AU). As of 2019 UniSA and University College London (UK) are offering a joint masters qualification in Science in Data Science (international).

    In 2018, University College London (UK) opened UCL at Here East, at the Queen Elizabeth Olympic Park, offering courses jointly between the Bartlett Faculty of the Built Environment and the Faculty of Engineering Sciences. The campus offers a variety of undergraduate and postgraduate master’s degrees, with the first undergraduate students, on a new Engineering and Architectural Design MEng, starting in September 2018. It was announced in August 2018 that a £215 million contract for construction of the largest building in the UCL East development, Marshgate 1, had been awarded to Mace, with building to begin in 2019 and be completed by 2022.

    In 2017 University College London (UK) disciplined an IT administrator who was also the University and College Union (UCU) branch secretary for refusing to take down an unmoderated staff mailing list. An employment tribunal subsequently ruled that he was engaged in union activities and thus this disciplinary action was unlawful. As of June 2019 University College London (UK) is appealing this ruling and the UCU congress has declared this to be a “dispute of national significance”.

    2020 to present

    In 2021 University College London (UK) formed a strategic partnership with Facebook AI Research (FAIR), including the creation of a new PhD programme.

    Research

    University College London (UK) has made cross-disciplinary research a priority and orientates its research around four “Grand Challenges”, Global Health, Sustainable Cities, Intercultural Interaction and Human Wellbeing.

    In 2014/15, University College London (UK) had a total research income of £427.5 million, the third-highest of any British university (after the University of Oxford and Imperial College London). Key sources of research income in that year were BIS research councils (£148.3 million); UK-based charities (£106.5 million); UK central government; local/health authorities and hospitals (£61.5 million); EU government bodies (£45.5 million); and UK industry, commerce and public corporations (£16.2 million). In 2015/16, University College London (UK) was awarded a total of £85.8 million in grants by UK research councils, the second-largest amount of any British university (after the University of Oxford), having achieved a 28% success rate. For the period to June 2015, University College London (UK) was the fifth-largest recipient of Horizon 2020 EU research funding and the largest recipient of any university, with €49.93 million of grants received. University College London (UK) also had the fifth-largest number of projects funded of any organisation, with 94.

    According to a ranking of universities produced by SCImago Research Group University College London (UK) is ranked 12th in the world (and 1st in Europe) in terms of total research output. According to data released in July 2008 by ISI Web of Knowledge, University College London (UK) is the 13th most-cited university in the world (and most-cited in Europe). The analysis covered citations from 1 January 1998 to 30 April 2008, during which 46,166 UCL research papers attracted 803,566 citations. The report covered citations in 21 subject areas and the results revealed some of University College London (UK) ‘s key strengths, including: Clinical Medicine (1st outside North America); Immunology (2nd in Europe); Neuroscience & Behaviour (1st outside North America and 2nd in the world); Pharmacology & Toxicology (1st outside North America and 4th in the world); Psychiatry & Psychology (2nd outside North America); and Social Sciences, General (1st outside North America).

    University College London (UK) submitted a total of 2,566 staff across 36 units of assessment to the 2014 Research Excellence Framework (REF) assessment, in each case the highest number of any UK university (compared with 1,793 UCL staff submitted to the 2008 Research Assessment Exercise (RAE 2008)). In the REF results 43% of University College London (UK) ‘s submitted research was classified as 4* (world-leading); 39% as 3* (internationally excellent); 15% as 2* (recognised internationally) and 2% as 1* (recognised nationally), giving an overall GPA of 3.22 (RAE 2008: 4* – 27%, 3* – 39%, 2* – 27% and 1* – 6%). In rankings produced by Times Higher Education based upon the REF results, University College London (UK) was ranked 1st overall for “research power” and joint 8th for GPA (compared to 4th and 7th respectively in equivalent rankings for the RAE 2008).

     
  • richardmitnick 4:12 pm on June 2, 2021 Permalink | Reply
    Tags: , , Extending the idea of dark matter ‘talking’ to dark forces., Fritz Zwicky and Vera Rubin, If two particles of dark matter are attracted to or repelled by each other then dark forces are operating., It is proposed that there may be a fourth dimension that only the dark forces know about., , , , The key feature of the extra-dimensional theory is that the force between dark matter particles is described by an infinite number of different particles with different masses called a continuum., The new research proposes the existence of an extra dimension in space-time., The team will explore a continuum version of the “dark photon” model., ,   

    From UC Riverside (US) : “A new dimension in the quest to understand dark matter” 

    UC Riverside bloc

    From UC Riverside (US)

    1
    Flip Tanedo.

    As its name suggests, Dark Matter — material which makes up about 85% of the mass in the universe — emits no light, eluding easy detection. Its properties, too, remain fairly obscure.

    _____________________________________________________________________________________

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.


    _____________________________________________________________________________________

    Now, a theoretical particle physicist at the University of California, Riverside, and colleagues have published a research paper in the Journal of High Energy Physics that shows how theories positing the existence a new type of force could help explain dark matter’s properties.

    2
    Photo shows Flip Tanedo (left), Sylvain Fichet (center), and Hai-Bo Yu. Credit: Flip Tanedo/UCR.

    “We live in an ocean of dark matter, yet we know very little about what it could be,” said Flip Tanedo, an assistant professor of physics and astronomy and the paper’s senior author. “It is one of the most vexing known unknowns in nature. We know it exists, but we do not know how to look for it or why it hasn’t shown up where we expected it.”

    Physicists have used telescopes, gigantic underground experiments, and colliders to learn more about dark matter for the last 30 years, though no positive evidence has materialized. The negative evidence, however, has forced theoretical physicists like Tanedo to think more creatively about what dark matter could be.

    The new research, which proposes the existence of an extra dimension in space-time to search for dark matter, is part of an ongoing research program at UC Riverside led by Tanedo. According to this theory, some of the dark matter particles don’t behave like particles. In effect, invisible particles interact with even more invisible particles in such a way that the latter cease to behave like particles.

    “The goal of my research program for the past two years is to extend the idea of dark matter ‘talking’ to dark forces,” Tanedo said. “Over the past decade, physicists have come to appreciate that, in addition to dark matter, hidden dark forces may govern dark matter’s interactions. These could completely rewrite the rules for how one ought to look for dark matter.”

    If two particles of dark matter are attracted to or repelled by each other then dark forces are operating. Tanedo explained that dark forces are described mathematically by a theory with extra dimensions and appear as a continuum of particles that could address puzzles seen in small galaxies.

    “Our ongoing research program at UCR is a further generalization of the dark force proposal,” he said. “Our observed universe has three dimensions of space. We propose that there may be a fourth dimension that only the dark forces know about. The extra dimension can explain why dark matter has hidden so well from our attempts to study it in a lab.”

    Tanedo explained that although extra dimensions may sound like an exotic idea, they are actually a mathematical trick to describe “conformal field theories” — ordinary three-dimensional theories that are highly quantum mechanical. These types of theories are mathematically rich, but do not contain conventional particles and so are typically not considered to be relevant for describing nature. The mathematical equivalence between these challenging three-dimensional theories and a more tractable extra dimensional theory is known as the holographic principle.

    “Since these conformal field theories were both intractable and unusual, they hadn’t really been systematically applied to dark matter,” Tanedo added. “Instead of using that language, we work with the holographic extra-dimensional theory.”

    The key feature of the extra-dimensional theory is that the force between dark matter particles is described by an infinite number of different particles with different masses called a continuum. In contrast, ordinary forces are described by a single type of particle with a fixed mass. This class of continuum-dark sectors is exciting to Tanedo because it does something “fresh and different.”

    According to Tanedo, past work on dark sectors focuses primarily on theories that mimic the behavior of visible particles. His research program is exploring the more extreme types of theories that most particle physicists found less interesting, perhaps because no analogs exist in the real world.

    In Tanedo’s theory, the force between dark matter particles is surprisingly different from the forces felt by ordinary matter.

    “For the gravitational force or electric force that I teach in my introductory physics course, when you double the distance between two particles you reduce the force by a factor of four. A continuum force, on the other hand, is reduced by a factor of up to eight.”

    What implications does this extra dimensional dark force have? Since ordinary matter may not interact with this dark force, Tanedo turned to the idea of self-interacting dark matter, an idea pioneered by Hai-Bo Yu, an associate professor of physics and astronomy at UCR who is not a coauthor on the paper. Yu showed that even in the absence of any interactions with normal matter, the effects of these dark forces could be observed indirectly in dwarf spheroidal galaxies. Tanedo’s team found the continuum force can reproduce the observed stellar motions.

    “Our model goes further and makes it easier than the self-interacting dark matter model to explain the cosmic origin of dark matter,” Tanedo said.

    Next, Tanedo’s team will explore a continuum version of the “dark photon” model.

    “It’s a more realistic picture for a dark force,” Tanedo said. “Dark photons have been studied in great detail, but our extra-dimensional framework has a few surprises. We will also look into the cosmology of dark forces and the physics of black holes.”

    Tanedo has been working diligently on identifying “blind spots” in his team’s search for dark matter.

    “My research program targets one of the assumptions we make about particle physics: that the interaction of particles is well-described by the exchange of more particles,” he said. “While that is true for ordinary matter, there’s no reason to assume that for dark matter. Their interactions could be described by a continuum of exchanged particles rather than just exchanging a single type of force particle.”

    Tanedo was joined in the research by Ian Chaffey, a postdoctoral researcher working with Tanedo; and Sylvain Fichet, a postdoctoral researcher at the International Center for Theoretical Physics – South American Institute for Fundamental Research in Brazil.

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

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Riverside Campus

    The University of California, Riverside (US) is a public land-grant research university in Riverside, California. It is one of the 10 campuses of the University of California (US) system. The main campus sits on 1,900 acres (769 ha) in a suburban district of Riverside with a branch campus of 20 acres (8 ha) in Palm Desert. In 1907, the predecessor to UC Riverside was founded as the UC Citrus Experiment Station, Riverside which pioneered research in biological pest control and the use of growth regulators responsible for extending the citrus growing season in California from four to nine months. Some of the world’s most important research collections on citrus diversity and entomology, as well as science fiction and photography, are located at Riverside.

    UC Riverside’s undergraduate College of Letters and Science opened in 1954. The Regents of the University of California declared UC Riverside a general campus of the system in 1959, and graduate students were admitted in 1961. To accommodate an enrollment of 21,000 students by 2015, more than $730 million has been invested in new construction projects since 1999. Preliminary accreditation of the UC Riverside School of Medicine was granted in October 2012 and the first class of 50 students was enrolled in August 2013. It is the first new research-based public medical school in 40 years.

    UC Riverside is classified among “R1: Doctoral Universities – Very high research activity.” The 2019 U.S. News & World Report Best Colleges rankings places UC Riverside tied for 35th among top public universities and ranks 85th nationwide. Over 27 of UC Riverside’s academic programs, including the Graduate School of Education and the Bourns College of Engineering, are highly ranked nationally based on peer assessment, student selectivity, financial resources, and other factors. Washington Monthly ranked UC Riverside 2nd in the United States in terms of social mobility, research and community service, while U.S. News ranks UC Riverside as the fifth most ethnically diverse and, by the number of undergraduates receiving Pell Grants (42 percent), the 15th most economically diverse student body in the nation. Over 70% of all UC Riverside students graduate within six years without regard to economic disparity. UC Riverside’s extensive outreach and retention programs have contributed to its reputation as a “university of choice” for minority students. In 2005, UCR became the first public university campus in the nation to offer a gender-neutral housing option.UC Riverside’s sports teams are known as the Highlanders and play in the Big West Conference of the National Collegiate Athletic Association (NCAA) Division I. Their nickname was inspired by the high altitude of the campus, which lies on the foothills of Box Springs Mountain. The UC Riverside women’s basketball team won back-to-back Big West championships in 2006 and 2007. In 2007, the men’s baseball team won its first conference championship and advanced to the regionals for the second time since the university moved to Division I in 2001.

    History

    At the turn of the 20th century, Southern California was a major producer of citrus, the region’s primary agricultural export. The industry developed from the country’s first navel orange trees, planted in Riverside in 1873. Lobbied by the citrus industry, the UC Regents established the UC Citrus Experiment Station (CES) on February 14, 1907, on 23 acres (9 ha) of land on the east slope of Mount Rubidoux in Riverside. The station conducted experiments in fertilization, irrigation and crop improvement. In 1917, the station was moved to a larger site, 475 acres (192 ha) near Box Springs Mountain.

    The 1944 passage of the GI Bill during World War II set in motion a rise in college enrollments that necessitated an expansion of the state university system in California. A local group of citrus growers and civic leaders, including many UC Berkeley(US) alumni, lobbied aggressively for a UC-administered liberal arts college next to the CES. State Senator Nelson S. Dilworth authored Senate Bill 512 (1949) which former Assemblyman Philip L. Boyd and Assemblyman John Babbage (both of Riverside) were instrumental in shepherding through the State Legislature. Governor Earl Warren signed the bill in 1949, allocating $2 million for initial campus construction.

    Gordon S. Watkins, dean of the College of Letters and Science at University of California at Los Angeles(US), became the first provost of the new college at Riverside. Initially conceived of as a small college devoted to the liberal arts, he ordered the campus built for a maximum of 1,500 students and recruited many young junior faculty to fill teaching positions. He presided at its opening with 65 faculty and 127 students on February 14, 1954, remarking, “Never have so few been taught by so many.”

    UC Riverside’s enrollment exceeded 1,000 students by the time Clark Kerr became president of the University of California(US) system in 1958. Anticipating a “tidal wave” in enrollment growth required by the baby boom generation, Kerr developed the California Master Plan for Higher Education and the Regents designated Riverside a general university campus in 1959. UC Riverside’s first chancellor, Herman Theodore Spieth, oversaw the beginnings of the school’s transition to a full university and its expansion to a capacity of 5,000 students. UC Riverside’s second chancellor, Ivan Hinderaker led the campus through the era of the free speech movement and kept student protests peaceful in Riverside. According to a 1998 interview with Hinderaker, the city of Riverside received negative press coverage for smog after the mayor asked Governor Ronald Reagan to declare the South Coast Air Basin a disaster area in 1971; subsequent student enrollment declined by up to 25% through 1979. Hinderaker’s development of innovative programs in business administration and biomedical sciences created incentive for enough students to enroll at Riverside to keep the campus open.

    In the 1990s, the UC Riverside experienced a new surge of enrollment applications, now known as “Tidal Wave II”. The Regents targeted UC Riverside for an annual growth rate of 6.3%, the fastest in the UC system, and anticipated 19,900 students at UC Riverside by 2010. By 1995, African American, American Indian, and Latino student enrollments accounted for 30% of the UC Riverside student body, the highest proportion of any UC campus at the time. The 1997 implementation of Proposition 209—which banned the use of affirmative action by state agencies—reduced the ethnic diversity at the more selective UC campuses but further increased it at UC Riverside.

    With UC Riverside scheduled for dramatic population growth, efforts have been made to increase its popular and academic recognition. The students voted for a fee increase to move UC Riverside athletics into NCAA Division I standing in 1998. In the 1990s, proposals were made to establish a law school, a medical school, and a school of public policy at UC Riverside, with the UC Riverside School of Medicine and the School of Public Policy becoming reality in 2012. In June 2006, UC Riverside received its largest gift, 15.5 million from two local couples, in trust towards building its medical school. The Regents formally approved UC Riverside’s medical school proposal in 2006. Upon its completion in 2013, it was the first new medical school built in California in 40 years.

    Academics

    As a campus of the University of California(US) system, UC Riverside is governed by a Board of Regents and administered by a president. The current president is Michael V. Drake, and the current chancellor of the university is Kim A. Wilcox. UC Riverside’s academic policies are set by its Academic Senate, a legislative body composed of all UC Riverside faculty members.

    UC Riverside is organized into three academic colleges, two professional schools, and two graduate schools. UC Riverside’s liberal arts college, the College of Humanities, Arts and Social Sciences, was founded in 1954, and began accepting graduate students in 1960. The College of Natural and Agricultural Sciences, founded in 1960, incorporated the CES as part of the first research-oriented institution at UC Riverside; it eventually also incorporated the natural science departments formerly associated with the liberal arts college to form its present structure in 1974. UC Riverside’s newest academic unit, the Bourns College of Engineering, was founded in 1989. Comprising the professional schools are the Graduate School of Education, founded in 1968, and the UCR School of Business, founded in 1970. These units collectively provide 81 majors and 52 minors, 48 master’s degree programs, and 42 Doctor of Philosophy (PhD) programs. UC Riverside is the only UC campus to offer undergraduate degrees in creative writing and public policy and one of three UCs (along with University of California-Berkeley (US) and University of California-Irvine (US)) to offer an undergraduate degree in business administration. Through its Division of Biomedical Sciences, founded in 1974, UC Riverside offers the Thomas Haider medical degree program in collaboration with University of California-Los Angeles(US). UC Riverside’s doctoral program in the emerging field of dance theory, founded in 1992, was the first program of its kind in the United States, and UC Riverside’s minor in lesbian, gay and bisexual studies, established in 1996, was the first undergraduate program of its kind in the UC system. A new BA program in bagpipes was inaugurated in 2007.

    Research and economic impact

    UC Riverside operated under a $727 million budget in fiscal year 2014–15. The state government provided $214 million, student fees accounted for $224 million and $100 million came from contracts and grants. Private support and other sources accounted for the remaining $189 million. Overall, monies spent at UC Riverside have an economic impact of nearly $1 billion in California. UC Riverside research expenditure in FY 2018 totaled $167.8 million. Total research expenditures at UC Riverside are significantly concentrated in agricultural science, accounting for 53% of total research expenditures spent by the university in 2002. Top research centers by expenditure, as measured in 2002, include the Agricultural Experiment Station; the Center for Environmental Research and Technology; the Center for Bibliographical Studies; the Air Pollution Research Center; and the Institute of Geophysics and Planetary Physics.

    Throughout UC Riverside’s history, researchers have developed more than 40 new citrus varieties and invented new techniques to help the $960 million-a-year California citrus industry fight pests and diseases. In 1927, entomologists at the CES introduced two wasps from Australia as natural enemies of a major citrus pest, the citrophilus mealybug, saving growers in Orange County $1 million in annual losses. This event was pivotal in establishing biological control as a practical means of reducing pest populations. In 1963, plant physiologist Charles Coggins proved that application of gibberellic acid allows fruit to remain on citrus trees for extended periods. The ultimate result of his work, which continued through the 1980s, was the extension of the citrus-growing season in California from four to nine months. In 1980, UC Riverside released the Oroblanco grapefruit, its first patented citrus variety. Since then, the citrus breeding program has released other varieties such as the Melogold grapefruit, the Gold Nugget mandarin (or tangerine), and others that have yet to be given trademark names.

    To assist entrepreneurs in developing new products, UC Riverside is a primary partner in the Riverside Regional Technology Park, which includes the City of Riverside and the County of Riverside. It also administers six reserves of the University of California Natural Reserve System. UC Riverside recently announced a partnership with China Agricultural University[中国农业大学](CN) to launch a new center in Beijing, which will study ways to respond to the country’s growing environmental issues. UC Riverside can also boast the birthplace of two name reactions in organic chemistry, the Castro-Stephens coupling and the Midland Alpine Borane Reduction.

     
  • richardmitnick 10:37 am on April 16, 2021 Permalink | Reply
    Tags: "Is Jupiter a key to finding dark matter?", , Fritz Zwicky and Vera Rubin, Jupiter’s large size and cool core make it an excellent target in the search for dark matter., , Stockholm University [Stockholm universitet](SE)   

    From Stanford University(US) and From Stockholm University [Stockholm universitet](SE) via EarthSky News: “Is Jupiter a key to finding dark matter?” 

    Stanford University Name

    From Stanford University(US)

    and

    From Stockholm University [Stockholms universitet](SE)

    via

    EarthSky News

    April 16, 2021
    Kelly Kizer

    Jupiter’s large size and cool core make it an excellent target in the search for dark matter. A team of scientists is analyzing gamma-ray data from the Fermi Telescope looking for signs of the elusive substance.

    1
    The Juno spacecraft captured this image of Jupiter during its 31st close flyby of the giant planet on December 30, 2020. The storm known as the Great Red Spot is visible on the horizon, nearly rotated out of view as Juno sped away from Jupiter at 30 miles (48 km) per second. Citizen scientist Tanya Oleksuik created this color-enhanced image using data from the JunoCam camera. See Juno’s image gallery. Image via National Aeronautics Space Agency (US).

    Two astrophysicists said on April 5, 2021, that Jupiter might serve as an ideal detector in the hunt for Dark Matter, the elusive and mysterious substance thought to make up a substantial fraction of our universe. Stanford University’s Rebecca Leane and Stockholm University’s Tim Linden released a draft version of a new paper, describing how that might work. These scientists list two reasons why our solar system’s largest planet might be an advantageous spot to search for dark matter: its size and its temperature. Leane explained:

    “Because Jupiter has a large surface area compared to other solar system planets, it can capture more dark matter… You might then wonder why not just use the even bigger (and very close by) sun. Well, the second advantage is that because Jupiter has a cooler core than the sun … This in part can stop lighter dark matter from evaporating out of Jupiter, which would have evaporated out of the sun.”

    Leane and Linden analyzed 12 years of data from the Fermi Telescope – a space observatory that sees the universe in high-energy gamma rays – in what they called:

    … the first dedicated gamma-ray analysis of Jupiter.

    They didn’t find robust evidence of gamma-ray emission from Jupiter that would’ve suggested dark matter, but they said Jupiter could be a target for future gamma-ray searches.

    Dark matter is an elusive substance – detectable via its gravitational influence on objects in space – called dark because no one has ever actually seen any. No one knows what dark matter is. According to a popular cosmological model called the Lambda Cold Dark Matter Model (aka the Lambda-CDM model, or sometimes just the Standard Model), ordinary atoms – the building blocks of our own bodies and all we see around us – make up only only around 5% of the universe.

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

    Think of that! Just 5%. The rest of the universe consists of dark energy (68%) and dark matter (27%), according to this popular theory.

    So dark matter is very mysterious. It’s possible that it’s an unidentified subatomic particle that interacts in different ways than scientists are used to.

    How would Jupiter be a source of dark matter? Rebecca Leane and Tim Linden pointed out that dark matter should be pulled into the gravitational wells of large objects, such as our sun and its largest planets. These scientists said that, eventually, enough dark matter would build up in a star or planet that the dark matter particles would run into each other, causing annihilations of dark matter particles. The gamma rays would be telltale sign of the annihilations. And while we can’t see dark matter, we can see gamma rays, thanks to observatories such as the Fermi Telescope.

    The Fermi Telescope, launched in 2008, looks for gamma radiation across the universe, from right here in our solar system to the farthest reaches of space. Fermi investigates black holes, supernovas, and, yes, Jupiter, where it has accumulated 12 years of data that the scientists mined for evidence of gamma rays that might signal the annihilation of dark matter.

    While Leane and Linden haven’t found dark matter from Jupiter yet, they did find an intriguing excess of gamma rays at low energy levels on the gas giant. They said they hope to study Jupiter with newer, more powerful telescopes that are still in the concept stage. These new telescopes would perform better at the lower end of their studies, where Fermi struggles.

    Leane thinks their method of looking for dark matter could be extrapolated out to exoplanets and brown dwarfs. Future studies would target these objects that are nearer to the center of the galaxy, where scientists believe more dark matter resides. The scientists think these objects would appear hotter in infrared than planets and stars further away, due to more frequent dark matter annihilation in their cores. They hope that the James Webb Space Telescope, which is scheduled to launch later this year, can provide an infrared survey to confirm their theory.

    Thus, despite the dim nature of dark matter, the possibility of future discoveries looks a bit brighter now.

    3
    Top left shows the gamma-ray counts in a 45-degree region around Jupiter. Top right shows the same part of the sky when Jupiter is not there (the background). Bottom left shows the gamma-ray counts leftover when the background is subtracted. Bottom right shows the size and position of Jupiter from the Fermi Telescope. If there was a gamma-ray excess, the bottom-left map should have lit up at Jupiter’s position. At these energy levels, it did not, although it did at lower energy levels, prompting the need for further observation with new telescopes. Credit: Rebecca Leane and Tim Linden.

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.

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

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

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Stockholm University [Stockholms universitet](SE) is a public university in Stockholm, Sweden, founded as a college in 1878, with university status since 1960. With over 33,000 students at four different faculties: law, humanities, social sciences, and natural sciences, it is one of the largest universities in Scandinavia. The institution is regarded as one of the top 100 universities in the world by the Academic Ranking of World Universities (ARWU).

    Stockholm University was granted university status in 1960, making it the fourth oldest Swedish university. As with other public universities in Sweden, Stockholm University’s mission includes teaching and research anchored in society at large.

    History

    The initiative for the formation of Stockholm University was taken by the Stockholm City Council. The process was completed after a decision in December 1865 regarding the establishment of a fund and a committee to “establish a higher education institution in the capital”. The nine members of the Committee were respected and prominent citizens whose work had helped the evolution of science and society.

    The next important step was taken in October 1869, when the Stockholm University College Association was established. Several members of the committee became members of the association – including Professor Pehr Henrik Malmsten. The association’s mission was to establish a college in Stockholm and would “not be dissolved until the college came into being and its future could be considered secure.” The memorandum of the Stockholm University College was adopted in May 1877, and in the autumn semester of the following year, actual operations began.

    In 1878, the university college Stockholms högskola started its operations with a series of lectures on natural sciences, open to curious citizens (a tradition still upheld by yearly publicly open lectures). Notable in the university’s early history is the appointment of Sofia Kovalevskaya to hold a chair in the mathematics department in 1889, making her the third female professor in Europe. In 1904 the college became an official degree granting institution.

    See the full article here .


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

    Stem Education Coalition

    Stanford University campus. No image credit

    Stanford University (US)

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members.

    Stanford University, officially Leland Stanford Junior University, is a private research university located in Stanford, California. Stanford was founded in 1885 by Leland and Jane Stanford in memory of their only child, Leland Stanford Jr., who had died of typhoid fever at age 15 the previous year. Stanford is consistently ranked as among the most prestigious and top universities in the world by major education publications. It is also one of the top fundraising institutions in the country, becoming the first school to raise more than a billion dollars in a year.

    Leland Stanford was a U.S. senator and former governor of California who made his fortune as a railroad tycoon. The school admitted its first students on October 1, 1891, as a coeducational and non-denominational institution. Stanford University struggled financially after the death of Leland Stanford in 1893 and again after much of the campus was damaged by the 1906 San Francisco earthquake. Following World War II, provost Frederick Terman supported faculty and graduates’ entrepreneurialism to build self-sufficient local industry in what would later be known as Silicon Valley.

    The university is organized around seven schools: three schools consisting of 40 academic departments at the undergraduate level as well as four professional schools that focus on graduate programs in law, medicine, education, and business. All schools are on the same campus. Students compete in 36 varsity sports, and the university is one of two private institutions in the Division I FBS Pac-12 Conference. It has gained 126 NCAA team championships, and Stanford has won the NACDA Directors’ Cup for 24 consecutive years, beginning in 1994–1995. In addition, Stanford students and alumni have won 270 Olympic medals including 139 gold medals.

    As of October 2020, 84 Nobel laureates, 28 Turing Award laureates, and eight Fields Medalists have been affiliated with Stanford as students, alumni, faculty, or staff. In addition, Stanford is particularly noted for its entrepreneurship and is one of the most successful universities in attracting funding for start-ups. Stanford alumni have founded numerous companies, which combined produce more than $2.7 trillion in annual revenue, roughly equivalent to the 7th largest economy in the world (as of 2020). Stanford is the alma mater of one president of the United States (Herbert Hoover), 74 living billionaires, and 17 astronauts. It is also one of the leading producers of Fulbright Scholars, Marshall Scholars, Rhodes Scholars, and members of the United States Congress.

    Stanford University was founded in 1885 by Leland and Jane Stanford, dedicated to Leland Stanford Jr, their only child. The institution opened in 1891 on Stanford’s previous Palo Alto farm.

    Jane and Leland Stanford modeled their university after the great eastern universities, most specifically Cornell University. Stanford opened being called the “Cornell of the West” in 1891 due to faculty being former Cornell affiliates (either professors, alumni, or both) including its first president, David Starr Jordan, and second president, John Casper Branner. Both Cornell and Stanford were among the first to have higher education be accessible, nonsectarian, and open to women as well as to men. Cornell is credited as one of the first American universities to adopt this radical departure from traditional education, and Stanford became an early adopter as well.

    Despite being impacted by earthquakes in both 1906 and 1989, the campus was rebuilt each time. In 1919, The Hoover Institution on War, Revolution and Peace was started by Herbert Hoover to preserve artifacts related to World War I. The Stanford Medical Center, completed in 1959, is a teaching hospital with over 800 beds. The DOE’s SLAC National Accelerator Laboratory(US)(originally named the Stanford Linear Accelerator Center), established in 1962, performs research in particle physics.

    Land

    Most of Stanford is on an 8,180-acre (12.8 sq mi; 33.1 km^2) campus, one of the largest in the United States. It is located on the San Francisco Peninsula, in the northwest part of the Santa Clara Valley (Silicon Valley) approximately 37 miles (60 km) southeast of San Francisco and approximately 20 miles (30 km) northwest of San Jose. In 2008, 60% of this land remained undeveloped.

    Stanford’s main campus includes a census-designated place within unincorporated Santa Clara County, although some of the university land (such as the Stanford Shopping Center and the Stanford Research Park) is within the city limits of Palo Alto. The campus also includes much land in unincorporated San Mateo County (including the SLAC National Accelerator Laboratory and the Jasper Ridge Biological Preserve), as well as in the city limits of Menlo Park (Stanford Hills neighborhood), Woodside, and Portola Valley.

    Non-central campus

    Stanford currently operates in various locations outside of its central campus.

    On the founding grant:

    Jasper Ridge Biological Preserve is a 1,200-acre (490 ha) natural reserve south of the central campus owned by the university and used by wildlife biologists for research.
    SLAC National Accelerator Laboratory is a facility west of the central campus operated by the university for the Department of Energy. It contains the longest linear particle accelerator in the world, 2 miles (3.2 km) on 426 acres (172 ha) of land.
    Golf course and a seasonal lake: The university also has its own golf course and a seasonal lake (Lake Lagunita, actually an irrigation reservoir), both home to the vulnerable California tiger salamander. As of 2012 Lake Lagunita was often dry and the university had no plans to artificially fill it.

    Off the founding grant:

    Hopkins Marine Station, in Pacific Grove, California, is a marine biology research center owned by the university since 1892.
    Study abroad locations: unlike typical study abroad programs, Stanford itself operates in several locations around the world; thus, each location has Stanford faculty-in-residence and staff in addition to students, creating a “mini-Stanford”.

    Redwood City campus for many of the university’s administrative offices located in Redwood City, California, a few miles north of the main campus. In 2005, the university purchased a small, 35-acre (14 ha) campus in Midpoint Technology Park intended for staff offices; development was delayed by The Great Recession. In 2015 the university announced a development plan and the Redwood City campus opened in March 2019.

    The Bass Center in Washington, DC provides a base, including housing, for the Stanford in Washington program for undergraduates. It includes a small art gallery open to the public.

    China: Stanford Center at Peking University, housed in the Lee Jung Sen Building, is a small center for researchers and students in collaboration with Beijing University [北京大学](CN) (Kavli Institute for Astronomy and Astrophysics at Peking University(CN) (KIAA-PKU).

    Administration and organization

    Stanford is a private, non-profit university that is administered as a corporate trust governed by a privately appointed board of trustees with a maximum membership of 38. Trustees serve five-year terms (not more than two consecutive terms) and meet five times annually.[83] A new trustee is chosen by the current trustees by ballot. The Stanford trustees also oversee the Stanford Research Park, the Stanford Shopping Center, the Cantor Center for Visual Arts, Stanford University Medical Center, and many associated medical facilities (including the Lucile Packard Children’s Hospital).

    The board appoints a president to serve as the chief executive officer of the university, to prescribe the duties of professors and course of study, to manage financial and business affairs, and to appoint nine vice presidents. The provost is the chief academic and budget officer, to whom the deans of each of the seven schools report. Persis Drell became the 13th provost in February 2017.

    As of 2018, the university was organized into seven academic schools. The schools of Humanities and Sciences (27 departments), Engineering (nine departments), and Earth, Energy & Environmental Sciences (four departments) have both graduate and undergraduate programs while the Schools of Law, Medicine, Education and Business have graduate programs only. The powers and authority of the faculty are vested in the Academic Council, which is made up of tenure and non-tenure line faculty, research faculty, senior fellows in some policy centers and institutes, the president of the university, and some other academic administrators, but most matters are handled by the Faculty Senate, made up of 55 elected representatives of the faculty.

    The Associated Students of Stanford University (ASSU) is the student government for Stanford and all registered students are members. Its elected leadership consists of the Undergraduate Senate elected by the undergraduate students, the Graduate Student Council elected by the graduate students, and the President and Vice President elected as a ticket by the entire student body.

    Stanford is the beneficiary of a special clause in the California Constitution, which explicitly exempts Stanford property from taxation so long as the property is used for educational purposes.

    Endowment and donations

    The university’s endowment, managed by the Stanford Management Company, was valued at $27.7 billion as of August 31, 2019. Payouts from the Stanford endowment covered approximately 21.8% of university expenses in the 2019 fiscal year. In the 2018 NACUBO-TIAA survey of colleges and universities in the United States and Canada, only Harvard University(US), the University of Texas System(US), and Yale University(US) had larger endowments than Stanford.

    In 2006, President John L. Hennessy launched a five-year campaign called the Stanford Challenge, which reached its $4.3 billion fundraising goal in 2009, two years ahead of time, but continued fundraising for the duration of the campaign. It concluded on December 31, 2011, having raised a total of $6.23 billion and breaking the previous campaign fundraising record of $3.88 billion held by Yale. Specifically, the campaign raised $253.7 million for undergraduate financial aid, as well as $2.33 billion for its initiative in “Seeking Solutions” to global problems, $1.61 billion for “Educating Leaders” by improving K-12 education, and $2.11 billion for “Foundation of Excellence” aimed at providing academic support for Stanford students and faculty. Funds supported 366 new fellowships for graduate students, 139 new endowed chairs for faculty, and 38 new or renovated buildings. The new funding also enabled the construction of a facility for stem cell research; a new campus for the business school; an expansion of the law school; a new Engineering Quad; a new art and art history building; an on-campus concert hall; a new art museum; and a planned expansion of the medical school, among other things. In 2012, the university raised $1.035 billion, becoming the first school to raise more than a billion dollars in a year.

    Research centers and institutes

    DOE’s SLAC National Accelerator Laboratory(US)
    Stanford Research Institute, a center of innovation to support economic development in the region.
    Hoover Institution, a conservative American public policy institution and research institution that promotes personal and economic liberty, free enterprise, and limited government.
    Hasso Plattner Institute of Design, a multidisciplinary design school in cooperation with the Hasso Plattner Institute of University of Potsdam [Universität Potsdam](DE) that integrates product design, engineering, and business management education).
    Martin Luther King Jr. Research and Education Institute, which grew out of and still contains the Martin Luther King Jr. Papers Project.
    John S. Knight Fellowship for Professional Journalists
    Center for Ocean Solutions
    Together with UC Berkeley(US) and UC San Francisco(US), Stanford is part of the Biohub, a new medical science research center founded in 2016 by a $600 million commitment from Facebook CEO and founder Mark Zuckerberg and pediatrician Priscilla Chan.

    Discoveries and innovation

    Natural sciences

    Biological synthesis of deoxyribonucleic acid (DNA) – Arthur Kornberg synthesized DNA material and won the Nobel Prize in Physiology or Medicine 1959 for his work at Stanford.
    First Transgenic organism – Stanley Cohen and Herbert Boyer were the first scientists to transplant genes from one living organism to another, a fundamental discovery for genetic engineering. Thousands of products have been developed on the basis of their work, including human growth hormone and hepatitis B vaccine.
    Laser – Arthur Leonard Schawlow shared the 1981 Nobel Prize in Physics with Nicolaas Bloembergen and Kai Siegbahn for his work on lasers.
    Nuclear magnetic resonance – Felix Bloch developed new methods for nuclear magnetic precision measurements, which are the underlying principles of the MRI.

    Computer and applied sciences

    ARPANETStanford Research Institute, formerly part of Stanford but on a separate campus, was the site of one of the four original ARPANET nodes.

    Internet—Stanford was the site where the original design of the Internet was undertaken. Vint Cerf led a research group to elaborate the design of the Transmission Control Protocol (TCP/IP) that he originally co-created with Robert E. Kahn (Bob Kahn) in 1973 and which formed the basis for the architecture of the Internet.

    Frequency modulation synthesis – John Chowning of the Music department invented the FM music synthesis algorithm in 1967, and Stanford later licensed it to Yamaha Corporation.

    Google – Google began in January 1996 as a research project by Larry Page and Sergey Brin when they were both PhD students at Stanford. They were working on the Stanford Digital Library Project (SDLP). The SDLP’s goal was “to develop the enabling technologies for a single, integrated and universal digital library” and it was funded through the National Science Foundation, among other federal agencies.

    Klystron tube – invented by the brothers Russell and Sigurd Varian at Stanford. Their prototype was completed and demonstrated successfully on August 30, 1937. Upon publication in 1939, news of the klystron immediately influenced the work of U.S. and UK researchers working on radar equipment.

    RISCARPA funded VLSI project of microprocessor design. Stanford and UC Berkeley are most associated with the popularization of this concept. The Stanford MIPS would go on to be commercialized as the successful MIPS architecture, while Berkeley RISC gave its name to the entire concept, commercialized as the SPARC. Another success from this era were IBM’s efforts that eventually led to the IBM POWER instruction set architecture, PowerPC, and Power ISA. As these projects matured, a wide variety of similar designs flourished in the late 1980s and especially the early 1990s, representing a major force in the Unix workstation market as well as embedded processors in laser printers, routers and similar products.
    SUN workstation – Andy Bechtolsheim designed the SUN workstation for the Stanford University Network communications project as a personal CAD workstation, which led to Sun Microsystems.

    Businesses and entrepreneurship

    Stanford is one of the most successful universities in creating companies and licensing its inventions to existing companies; it is often held up as a model for technology transfer. Stanford’s Office of Technology Licensing is responsible for commercializing university research, intellectual property, and university-developed projects.

    The university is described as having a strong venture culture in which students are encouraged, and often funded, to launch their own companies.

    Companies founded by Stanford alumni generate more than $2.7 trillion in annual revenue, equivalent to the 10th-largest economy in the world.

    Some companies closely associated with Stanford and their connections include:

    Hewlett-Packard, 1939, co-founders William R. Hewlett (B.S, PhD) and David Packard (M.S).
    Silicon Graphics, 1981, co-founders James H. Clark (Associate Professor) and several of his grad students.
    Sun Microsystems, 1982, co-founders Vinod Khosla (M.B.A), Andy Bechtolsheim (PhD) and Scott McNealy (M.B.A).
    Cisco, 1984, founders Leonard Bosack (M.S) and Sandy Lerner (M.S) who were in charge of Stanford Computer Science and Graduate School of Business computer operations groups respectively when the hardware was developed.[163]
    Yahoo!, 1994, co-founders Jerry Yang (B.S, M.S) and David Filo (M.S).
    Google, 1998, co-founders Larry Page (M.S) and Sergey Brin (M.S).
    LinkedIn, 2002, co-founders Reid Hoffman (B.S), Konstantin Guericke (B.S, M.S), Eric Lee (B.S), and Alan Liu (B.S).
    Instagram, 2010, co-founders Kevin Systrom (B.S) and Mike Krieger (B.S).
    Snapchat, 2011, co-founders Evan Spiegel and Bobby Murphy (B.S).
    Coursera, 2012, co-founders Andrew Ng (Associate Professor) and Daphne Koller (Professor, PhD).

    Student body

    Stanford enrolled 6,996 undergraduate and 10,253 graduate students as of the 2019–2020 school year. Women comprised 50.4% of undergraduates and 41.5% of graduate students. In the same academic year, the freshman retention rate was 99%.

    Stanford awarded 1,819 undergraduate degrees, 2,393 master’s degrees, 770 doctoral degrees, and 3270 professional degrees in the 2018–2019 school year. The four-year graduation rate for the class of 2017 cohort was 72.9%, and the six-year rate was 94.4%. The relatively low four-year graduation rate is a function of the university’s coterminal degree (or “coterm”) program, which allows students to earn a master’s degree as a 1-to-2-year extension of their undergraduate program.

    As of 2010, fifteen percent of undergraduates were first-generation students.

    Athletics

    As of 2016 Stanford had 16 male varsity sports and 20 female varsity sports, 19 club sports and about 27 intramural sports. In 1930, following a unanimous vote by the Executive Committee for the Associated Students, the athletic department adopted the mascot “Indian.” The Indian symbol and name were dropped by President Richard Lyman in 1972, after objections from Native American students and a vote by the student senate. The sports teams are now officially referred to as the “Stanford Cardinal,” referring to the deep red color, not the cardinal bird. Stanford is a member of the Pac-12 Conference in most sports, the Mountain Pacific Sports Federation in several other sports, and the America East Conference in field hockey with the participation in the inter-collegiate NCAA’s Division I FBS.

    Its traditional sports rival is the University of California, Berkeley, the neighbor to the north in the East Bay. The winner of the annual “Big Game” between the Cal and Cardinal football teams gains custody of the Stanford Axe.

    Stanford has had at least one NCAA team champion every year since the 1976–77 school year and has earned 126 NCAA national team titles since its establishment, the most among universities, and Stanford has won 522 individual national championships, the most by any university. Stanford has won the award for the top-ranked Division 1 athletic program—the NACDA Directors’ Cup, formerly known as the Sears Cup—annually for the past twenty-four straight years. Stanford athletes have won medals in every Olympic Games since 1912, winning 270 Olympic medals total, 139 of them gold. In the 2008 Summer Olympics, and 2016 Summer Olympics, Stanford won more Olympic medals than any other university in the United States. Stanford athletes won 16 medals at the 2012 Summer Olympics (12 gold, two silver and two bronze), and 27 medals at the 2016 Summer Olympics.

    Traditions

    The unofficial motto of Stanford, selected by President Jordan, is Die Luft der Freiheit weht. Translated from the German language, this quotation from Ulrich von Hutten means, “The wind of freedom blows.” The motto was controversial during World War I, when anything in German was suspect; at that time the university disavowed that this motto was official.
    Hail, Stanford, Hail! is the Stanford Hymn sometimes sung at ceremonies or adapted by the various University singing groups. It was written in 1892 by mechanical engineering professor Albert W. Smith and his wife, Mary Roberts Smith (in 1896 she earned the first Stanford doctorate in Economics and later became associate professor of Sociology), but was not officially adopted until after a performance on campus in March 1902 by the Mormon Tabernacle Choir.
    “Uncommon Man/Uncommon Woman”: Stanford does not award honorary degrees, but in 1953 the degree of “Uncommon Man/Uncommon Woman” was created to recognize individuals who give rare and extraordinary service to the University. Technically, this degree is awarded by the Stanford Associates, a voluntary group that is part of the university’s alumni association. As Stanford’s highest honor, it is not conferred at prescribed intervals, but only when appropriate to recognize extraordinary service. Recipients include Herbert Hoover, Bill Hewlett, Dave Packard, Lucile Packard, and John Gardner.
    Big Game events: The events in the week leading up to the Big Game vs. UC Berkeley, including Gaieties (a musical written, composed, produced, and performed by the students of Ram’s Head Theatrical Society).
    “Viennese Ball”: a formal ball with waltzes that was initially started in the 1970s by students returning from the now-closed Stanford in Vienna overseas program. It is now open to all students.
    “Full Moon on the Quad”: An annual event at Main Quad, where students gather to kiss one another starting at midnight. Typically organized by the Junior class cabinet, the festivities include live entertainment, such as music and dance performances.
    “Band Run”: An annual festivity at the beginning of the school year, where the band picks up freshmen from dorms across campus while stopping to perform at each location, culminating in a finale performance at Main Quad.
    “Mausoleum Party”: An annual Halloween Party at the Stanford Mausoleum, the final resting place of Leland Stanford Jr. and his parents. A 20-year tradition, the “Mausoleum Party” was on hiatus from 2002 to 2005 due to a lack of funding, but was revived in 2006. In 2008, it was hosted in Old Union rather than at the actual Mausoleum, because rain prohibited generators from being rented. In 2009, after fundraising efforts by the Junior Class Presidents and the ASSU Executive, the event was able to return to the Mausoleum despite facing budget cuts earlier in the year.
    Former campus traditions include the “Big Game bonfire” on Lake Lagunita (a seasonal lake usually dry in the fall), which was formally ended in 1997 because of the presence of endangered salamanders in the lake bed.

    Award laureates and scholars

    Stanford’s current community of scholars includes:

    19 Nobel Prize laureates (as of October 2020, 85 affiliates in total)
    171 members of the National Academy of Sciences
    109 members of National Academy of Engineering
    76 members of National Academy of Medicine
    288 members of the American Academy of Arts and Sciences
    19 recipients of the National Medal of Science
    1 recipient of the National Medal of Technology
    4 recipients of the National Humanities Medal
    49 members of American Philosophical Society
    56 fellows of the American Physics Society (since 1995)
    4 Pulitzer Prize winners
    31 MacArthur Fellows
    4 Wolf Foundation Prize winners
    2 ACL Lifetime Achievement Award winners
    14 AAAI fellows
    2 Presidential Medal of Freedom winners

    Stanford University Seal

     
  • richardmitnick 1:21 pm on February 25, 2021 Permalink | Reply
    Tags: "New study suggests supermassive black holes could form from dark matter", , , , , Fritz Zwicky and Vera Rubin, Royal Astronomical Society(UK), The new work investigates the potential existence of stable galactic cores made of dark matter.   

    From Royal Astronomical Society(UK): “New study suggests supermassive black holes could form from dark matter” 

    From Royal Astronomical Society(UK)

    2.25.21

    Media contacts

    Dr Morgan Hollis
    Royal Astronomical Society
    Mob: +44 (0)7802 877 700
    press@ras.ac.uk

    Dr Robert Massey
    Royal Astronomical Society
    Mob: +44 (0)7802 877 699
    press@ras.ac.uk

    Science contacts

    Dr Carlos R. Argüelles
    Facultad de Ciencias Astronómicas y Geofísicas
    Universidad Nacional de La Plata
    Buenos Aires
    Argentina
    carguelles@fcaglp.fcaglp.unlp.edu.ar

    1
    Artist’s impression of a spiral galaxy embedded in a larger distribution of invisible dark matter, known as a dark matter halo (coloured in blue). Studies looking at the formation of dark matter haloes have suggested that each halo could harbour a very dense nucleus of dark matter, which may potentially mimic the effects of a central black hole, or eventually collapse to form one. Credit: ESO / L. Calçada Licence type Attribution (CC BY 4.0).

    A new theoretical study has proposed a novel mechanism for the creation of supermassive black holes from Dark Matter. The international team find that rather than the conventional formation scenarios involving ‘normal’ matter, supermassive black holes could instead form directly from dark matter in high density regions in the centres of galaxies. The result has key implications for cosmology in the early Universe, and is published in MNRAS.

    Exactly how supermassive black holes initially formed is one of the biggest problems in the study of galaxy evolution today. Supermassive black holes have been observed as early as 800 million years after the Big Bang, and how they could grow so quickly remains unexplained.

    Standard formation models involve normal baryonic matter – the atoms and elements that that make up stars, planets, and all visible objects – collapsing under gravity to form black holes, which then grow over time. However the new work investigates the potential existence of stable galactic cores made of dark matter, and surrounded by a diluted dark matter halo, finding that the centres of these structures could become so concentrated that they could also collapse into supermassive black holes once a critical threshold is reached.

    According to the model this could have happened much more quickly than other proposed formation mechanisms, and would have allowed supermassive black holes in the early Universe to form before the galaxies they inhabit, contrary to current understanding.

    Carlos R. Argüelles, the researcher at La Plata National University [Universidad Nacional de La Plata](AR) and ICRANet who led the investigation comments: “This new formation scenario may offer a natural explanation for how supermassive black holes formed in the early Universe, without requiring prior star formation or needing to invoke seed black holes with unrealistic accretion rates.”

    Another intriguing consequence of the new model is that the critical mass for collapse into a black hole might not be reached for smaller dark matter halos, for example those surrounding some dwarf galaxies. The authors suggest that this then might leave smaller dwarf galaxies with a central dark matter nucleus rather than the expected black hole. Such a dark matter core could still mimic the gravitational signatures of a conventional central black hole, whilst the dark matter outer halo could also explain the observed galaxy rotation curves.

    “This model shows how dark matter haloes could harbour dense concentrations at their centres, which may play a crucial role in helping to understand the formation of supermassive black holes,” added Carlos.

    “Here we’ve proven for the first time that such core–halo dark matter distributions can indeed form in a cosmological framework, and remain stable for the lifetime of the Universe.”

    The authors hope that further studies will shed more light on supermassive black hole formation in the very earliest days of our Universe, as well as investigating whether the centres of non-active galaxies, including our own Milky Way, may play host to these dense dark matter cores.

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.

    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 Royal Astronomical Society(UK), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,400 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

    The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

    In 2020 the RAS is 200 years old. The Society is celebrating its bicentennial anniversary with a series of events around the UK, including public lectures, exhibitions, an organ recital, a pop-up planetarium, and the culmination of the RAS 200: Sky & Earth project.

     
  • richardmitnick 9:51 am on February 23, 2021 Permalink | Reply
    Tags: "Really Small Black Holes Could Be Out There Devouring Neutron Stars From Within", , , , , , , Endoparasitic black hole, Fritz Zwicky and Vera Rubin, , Tiny all-but-undetectable primordial black holes could be one of the mysterious sources of mass that contributes to Dark Matter.,   

    From University of Illinois at Urbana–Champaign via Science Alert(AU): “Really Small Black Holes Could Be Out There Devouring Neutron Stars From Within” 

    From University of Illinois at Urbana–Champaign

    via

    ScienceAlert

    Science Alert(AU)

    23 FEBRUARY 2021
    MICHELLE STARR

    1
    Credit: Victor de Schwanberg/Science Photo Library/Getty Images.

    Tiny, all-but-undetectable primordial black holes could be one of the mysterious sources of mass that contributes to Dark Matter. There are significant limits to their lifespan in open space, but in recent years, astrophysicists have asked: what if these black holes are in the core of neutron stars?

    Gradually, such black holes would accrete the neutron star, devouring it from within. These hypothetical systems are yet to be verified, but a new paper [Accretion onto a small black hole at the center of a neutron star], yet to be peer-reviewed, has calculated how long this devouring would take.

    This, in turn, could be used to analyse the current neutron star population to constrain the nature of the black holes considered as a dark matter candidate – whether they are primordial, dating back to the Big Bang, or black holes that formed inside neutron stars.

    Although we don’t know what dark matter is, it’s pretty fundamental to our understanding of the Universe: there simply isn’t enough matter we can directly detect – normal matter – to account for all the gravity. In fact, there’s so much gravity that scientists have calculated roughly 75 to 80 percent of all matter is dark.

    There are a number of candidate particles that could be dark matter. Primordial black holes that formed just after the Big Bang are not one of the leading candidates, because if they were above a certain mass we would have noticed them by now; but, below that mass, they would have evaporated via the emission of Hawking Radiation long before now.

    Black holes, however, are an attractive candidate for dark matter: they, too, are extremely difficult to detect if they’re just hanging out in space just doing nothing. So astronomers continue to look for them.

    One idea that has been explored recently is the endoparasitic black hole. There are two scenarios for this. One is that primordial black holes were captured by neutron stars, and sink down to the core. The other is that dark matter particles are captured inside a neutron star; if the conditions are favourable, these could then come together and collapse down into a black hole.

    These black holes are small, but they wouldn’t remain so. From their position, ensconced inside the neutron star, these little black holes would then parasitise their host.

    The team of physicists from Bowdoin College and the University of Illinois at Urbana-Champaign calculated the accretion rate – that is, the rate at which the black hole would devour the neutron star – for a range of black hole mass ratios, from three to nine orders of magnitude less massive than the neutron star host.

    Neutron stars have a theoretical upper mass limit of 2.3 times the mass of the Sun, so the black hole masses would extend down into the range of dwarf planets.

    For a non-rotating neutron star hosting a non-spinning black hole, the accretion would be spherical. At the team’s calculated accretion rates, black holes as small as 10-21 times the mass of the Sun would completely accrete a neutron star well within the lifetime of the Universe.

    This suggests that primordial black holes, from the beginning of the Universe, would have completely accreted their host neutron stars before now. These timescales are in direct conflict with the ages of old neutron star populations, the researchers said.

    “As an important application, our results corroborate arguments that use the current existence of neutron star populations to constrain either the contribution of primordial black holes to the dark matter content of the Universe, or that of dark matter particles that may form black holes at the center of neutron stars after they have been captured,” they wrote in their paper.

    So the result is another blow for primordial black holes; but it doesn’t rule endoparasitic black holes out entirely. If there are globs of dark matter particles out there floating through space and being slurped into neutron stars, they could be collapsing into black holes and converting neutron stars into black hole stuff even as you read this sentence.

    And that is freaking awesome.

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, some 30 years later, did most of the work on Dark Matter.

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


    Coma cluster via NASA/ESA Hubble.


    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.
    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.

    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 University of Illinois at Urbana-Champaign community of students, scholars, and alumni is changing the world.

    The University of Illinois at Urbana–Champaign (U of I, Illinois, or colloquially the University of Illinois or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the University of Illinois system and was founded in 1867.

    The University of Illinois at Urbana–Champaign is a member of the Association of American Universities and is classified among “R1: Doctoral Universities – Very high research activity”, and has been listed as a “Public Ivy” in The Public Ivies: America’s Flagship Public Universities (2001) by Howard and Matthew Greene. In fiscal year 2019, research expenditures at Illinois totaled $652 million. The campus library system possesses the second-largest university library in the United States by holdings after Harvard University. The university also hosts the National Center for Supercomputing Applications (NCSA) and is home to the fastest supercomputer on a university campus.

    The university contains 16 schools and colleges and offers more than 150 undergraduate and over 100 graduate programs of study. The university holds 651 buildings on 6,370 acres (2,578 ha). The University of Illinois at Urbana–Champaign also operates a Research Park home to innovation centers for over 90 start-up companies and multinational corporations, including Abbott, AbbVie, Caterpillar, Capital One, Dow, State Farm, and Yahoo, among others.

    As of August 2020, the alumni, faculty members, or researchers of the university include 30 Nobel laureates, 27 Pulitzer Prize winners, 2 Turing Award winners and 1 Fields medalist. Illinois athletic teams compete in Division I of the NCAA and are collectively known as the Fighting Illini. They are members of the Big Ten Conference and have won the second-most conference titles. Illinois Fighting Illini football won the Rose Bowl Game in 1947, 1952, 1964 and a total of five national championships. Illinois athletes have won 29 medals in Olympic events, ranking it among the top 40 American universities with Olympic medals.

    Illinois Industrial University

    The original University Hall, which stood until 1938, when it was replaced by Gregory Hall and the Illini Union. Pieces were used in the erection of Hallene Gateway dedicated in 1998.

    The University of Illinois, originally named “Illinois Industrial University”, was one of the 37 universities created under the first Morrill Land-Grant Act, which provided public land for the creation of agricultural and industrial colleges and universities across the United States. Among several cities, Urbana was selected in 1867 as the site for the new school.[19][20] From the beginning, President John Milton Gregory’s desire to establish an institution firmly grounded in the liberal arts tradition was at odds with many state residents and lawmakers who wanted the university to offer classes based solely around “industrial education”.[21] The university opened for classes on March 2, 1868, and had two faculty members and 77 students.

    The Library, which opened with the school in 1868, started with 1,039 volumes. Subsequently, President Edmund J. James, in a speech to the board of trustees in 1912, proposed to create a research library. It is now one of the world’s largest public academic collections. In 1870, the Mumford House was constructed as a model farmhouse for the school’s experimental farm. The Mumford House remains the oldest structure on campus. The original University Hall (1871) was the fourth building built; it stood where the Illini Union stands today.

    University of Illinois

    In 1885, the Illinois Industrial University officially changed its name to the “University of Illinois”, reflecting its agricultural, mechanical, and liberal arts curriculum.

    During his presidency, Edmund J. James (1904–1920) is credited for building the foundation for the large Chinese international student population on campus. James established ties with China through the Chinese Minister to the United States Wu Ting-Fang. In addition, during James’s presidency, class rivalries and Bob Zuppke’s winning football teams contributed to campus morale.

    Like many universities, the economic depression slowed construction and expansion on the campus. The university replaced the original university hall with Gregory Hall and the Illini Union. After World War II, the university experienced rapid growth. The enrollment doubled and the academic standing improved. This period was also marked by large growth in the Graduate College and increased federal support of scientific and technological research. During the 1950s and 1960s the university experienced the turmoil common on many American campuses. Among these were the water fights of the fifties and sixties.

    University of Illinois at Urbana–Champaign

    By 1967 the University of Illinois system consisted of a main campus in Champaign-Urbana and two Chicago campuses, Chicago Circle (UICC) and Medical Center (UIMC), and people began using “Urbana–Champaign” or the reverse to refer to the main campus specifically. The university name officially changed to the “University of Illinois at Urbana–Champaign” around 1982. While this was a reversal of the commonly used designation for the metropolitan area, “Champaign-Urbana,” most of the campus is located in Urbana. The name change established a separate identity for the main campus within the University of Illinois system, which today includes campuses in Springfield (UIS) and Chicago (UIC) (formed by the merger of UICC and UIMC).

    In 1998, the Hallene Gateway Plaza was dedicated. The Plaza features the original sandstone portal of University Hall, which was originally the fourth building on campus. In recent years, state support has declined from 4.5% of the state’s tax appropriations in 1980 to 2.28% in 2011, a nearly 50% decline. As a result, the university’s budget has shifted away from relying on state support with nearly 84% of the budget now coming from other sources.

    On March 12, 2015, the Board of Trustees approved the creation of a medical school, the first college created at Urbana–Champaign in 60 years. The Carle-Illinois College of Medicine began classes in 2018.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Illinois campus

    The University of Illinois at Urbana-Champaign community of students, scholars, and alumni is changing the world.

    With our land-grant heritage as a foundation, we pioneer innovative research that tackles global problems and expands the human experience. Our transformative learning experiences, in and out of the classroom, are designed to produce alumni who desire to make a significant, societal impact.

    The University of Illinois at Chicago (UIC) is a public research university in Chicago, Illinois. Its campus is in the Near West Side community area, adjacent to the Chicago Loop. The second campus established under the University of Illinois system, UIC is also the largest university in the Chicago area, having approximately 30,000 students enrolled in 15 colleges.

    UIC operates the largest medical school in the United States with research expenditures exceeding $412 million and consistently ranks in the top 50 U.S. institutions for research expenditures. In the 2019 U.S. News & World Report’s ranking of colleges and universities, UIC ranked as the 129th best in the “national universities” category. The 2015 Times Higher Education World University Rankings ranked UIC as the 18th best in the world among universities less than 50 years old.

    UIC competes in NCAA Division I Horizon League as the UIC Flames in sports. The Credit Union 1 Arena (formerly UIC Pavilion) is the Flames’ venue for home games.

     
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