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  • richardmitnick 12:23 pm on June 19, 2018 Permalink | Reply
    Tags: , , Symmetry Magazine, Waiting for a sign   

    From Symmetry: “Waiting for a sign” 

    Symmetry Mag
    From Symmetry

    06/19/18
    Diana Kwon

    Some scientists spend decades trying to catch a glimpse of a rare process. But with good experimental design and a lot of luck, they often need only a handful of signals to make a discovery.

    In 2009, University of Naples physicist Giovanni de Lellis had a routine. Almost every day, he would sit at a microscope to examine the data from his experiment, the Oscillation Project with Emulsion-tRacking Apparatus, or OPERA, located in Gran Sasso, Italy. He was seeking the same thing he had been looking for since 1996, when he was with the CHORUS experiment at CERN: a tau neutrino.

    OPERA at Gran Sasso

    CHORUS installation at CERN

    More specifically, he was looking for evidence of a muon neutrino oscillating into a tau neutrino.

    Neutrinos come in three flavors: electron, muon and tau. At the time, scientists knew that they oscillated, changing flavors as they traveled at close to the speed of light. But they had never seen a muon neutrino transform into a tau neutrino.

    Until November 30, 2009. On that day, de Lellis and the rest of the OPERA collaboration spotted their first tau neutrino in a beam of muon neutrinos coming from CERN research center 730 kilometers away.

    “Normally, what you would do is look and look, and nothing comes,” says de Lellis, now spokesperson for the OPERA collaboration. “So it’s quite an exciting moment when you spot your event.”

    For physicists seeking rare events, patience is key. Experiments like these often involve many years of waiting for a signal to appear. Some phenomena, such as neutrinoless double-beta decay, proton decay and dark matter, continue to elude researchers, despite decades of searching.

    Still, scientists hope that after the lengthy wait, there will be a worthwhile reward. Finding neutrinoless double-beta decay would let researchers know that neutrinos are actually their own antiparticles and help explain why there’s more matter than antimatter. Discovering proton decay would test several grand unified theories—and let us know that one of the key components of atoms doesn’t last forever. And discovering dark matter would finally tell us what makes up about a quarter of the mass and energy in the universe.

    “These are really hard experiments,” says Reina Maruyama, a physicist at Yale University working on neutrinoless double-beta decay experiment CUORE (Cryogenic Underground Observatory for Rare Events) as well as a number of direct dark matter searches.

    CUORE experiment,at the Italian National Institute for Nuclear Physics’ (INFN’s) Gran Sasso National Laboratories (LNGS) in Italy,a search for neutrinoless double beta decay

    “But they will help answer really fundamental questions that have implications for how the universe was put together.”

    Seeking signs, cutting noise

    For the OPERA collaboration, finding a likely tau neutrino candidate was just the beginning. Hours of additional work, including further analyses and verification from other scientists, were required to confirm that signal didn’t originate from another source.

    Luckily, the first signal passed all the checks, and the team was able to observe four more candidate events in the following years. By 2015, the team had gathered enough data to confidently confirm that muon neutrinos had transformed into tau neutrinos. More specifically, they were able to achieve a 5Σ result, the gold standard of detection in particle physics, which means there’s only a 1 in 3.5 million chance that the signal from an experiment was a fluke.

    For some experiments, seeing as few as two or three events could be enough to make a discovery, says Tiziano Camporesi, a physicist working on the CMS experiment at CERN.

    CERN/CMS Detector

    This was true when scientists at CERN’s Super Proton Synchrotron discovered the Z boson, a neutral elementary particle carrying the weak force, in 1983. “The Z boson discovery was basically made looking at three events,” Camporesi says, “but these three events were so striking that no other kind of particle being produced at the accelerator at the time could fake it.”

    Z boson depiction

    There are a number of ways scientists can improve their odds of catching an elusive event. In general, they can boost signals by making their detectors bigger and by improving the speed and precision with which they record incoming events.

    But a lot depends on background noise: How prevalent are other phenomena that could create a false signal that looks like the one the scientists are searching for?

    When it comes to rare events, scientists often have to go to great lengths to eliminate—or at least reduce—all sources of potential background noise. “Designing an experiment that is immune to background is challenging,” says Augusto Ceccucci, spokesperson for NA62, an experiment searching for an extremely rare kaon decay.

    For its part, NA62 scientists remove background noise by, for example, studying only the decay products that coincide in time with the passage of incoming particles from a kaon beam, and carefully identifying the characteristics of signals that could mimic what they’re looking for so they can eliminate them.

    The Super Cryogenic Dark Matter Search experiment, or SuperCDMS, led by SLAC National Accelerator Laboratory, goes to great lengths to protect its detectors from cosmic rays, particles that regularly rain down on Earth from space.

    SLAC SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    SLAC SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    To eliminate this source of background, scientists shield the detectors with iron, ship them by ground and sea, and operate them deep underground. “So it would not take many dark matter particles detected to satisfy the 5-sigma detection rule,” says Fermilab’s Dan Bauer, spokesperson for SuperCDMS.

    At particle accelerators, the search for rare phenomena looks a little different. Rather than simply waiting for a particle to show up in a detector, physicists try to create them in particle collisions. The more elusive a phenomenon is, the more collisions it requires to find. Thus, at the Large Hadron Collider, “in order to achieve smaller and smaller probability of production, we’re getting more and more intense beams,” Camporesi says.

    Triangulating the results of different experiments can help scientists build a picture of the particles or processes they’re looking for without actually finding them. For example, by understanding what dark matter is not, physicists can constrain what it could be. “You take combinations of different experiments and you start rejecting different hypotheses,” Maruyama says.

    Only time will tell whether scientists will be able to detect neutrinoless double-beta decay, proton decay, dark matter or other rare events that have yet to be spotted at physicists’ detectors. But once they do—and once scientists know what specific signatures to find, Maruyama says, “it becomes a lot easier to look for these things, and you can go ahead and study the heck out of them.”

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


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  • richardmitnick 11:52 am on June 19, 2018 Permalink | Reply
    Tags: , , , Halina Abramowicz, , , , Symmetry Magazine,   

    From Symmetry: Women in STEM-“Q&A: Planning Europe’s physics future” Halina Abramowicz 

    Symmetry Mag
    From Symmetry

    06/13/18
    Lauren Biron

    1
    Artwork by Sandbox Studio, Chicago

    Halina Abramowicz leads the group effort to decide the future of European particle physics.

    Physics projects are getting bigger, more global, more collaborative and more advanced than ever—with long lead times for complex physics machines. That translates into more international planning to set the course for the future.

    In 2014, the United States particle physics community set its priorities for the coming years using recommendations from the Particle Physics Project Prioritization Panel, or P5.

    FNAL Particle Physics Project Prioritization Panel -P5

    In 2020, the European community will refresh its vision with the European Strategy Update for Particle Physics.

    The first European strategy launched in 2006 and was revisited in 2013. In 2019, teams will gather input through planning meetings in preparation for the next refresh.

    Halina Abramowicz, a physicist who works on the ATLAS experiment at CERN’s Large Hadron Collider and the FCAL research and development collaboration through Tel Aviv University, is the chair of the massive undertaking. During a visit to Fermilab to provide US-based scientists with an overview of the process, she sat down with Symmetry writer Lauren Biron to discuss the future of physics in Europe.

    LB:What do you hope to achieve with the next European Strategy Update for Particle Physics?
    HA: Europe is a very good example of the fact that particle physics is very international, because of the size of the infrastructure that we need to progress, and because of the financial constraints.

    The community of physicists working on particle physics is very large; Europe has probably about 10,000 physicists. They have different interests, different expertise, and somehow, we have to make sure to have a very balanced program, such that the community is satisfied, and that at the same time it remains attractive, dynamic, and pushing the science forward. We have to take into account the interests of various national programs, universities, existing smaller laboratories, CERN, and make sure that there is a complementarity, a spread of activities—because that’s the way to keep the field attractive, that is, to be able to answer more questions faster.

    LB: How do you decide when to revisit the European plan for particle physics?
    HA: Once the Higgs was discovered, it became clear that it was time to revisit the strategy, and the first update happened in 2013. The recommendation was to vigorously pursue the preparations for the high-luminosity upgrade of the [Large Hadron Collider].

    The high-luminosity LHC program was formally approved by the CERN Council in September 2016. By the end of 2018, the LHC experiments will have collected almost a factor of 10 more data. It will be a good time to reflect on the latest results, to think about mid-term plans, to discuss what are the different options to consider next and their possible timelines, and to ponder what would make sense as we look into the long-term future.

    CERN HL-LHC map

    Machines, Projects and Experiments operating at CERN LHC and CLIC at three levels of power

    The other aspect which is very important is the fact that the process is called “strategy,” rather than “roadmap,” because it is a discussion not only of the scientific goals and associated projects, but also of how to achieve them. The strategy basically is about everything that the community should be doing in order to achieve the roadmap.

    LB: What’s the difference between a strategy and a roadmap?
    HA: The roadmap is about prioritizing the scientific goals and about the way to address them, while the strategy covers also all the different aspects to consider in order to make the program a success. For example, outreach is part of the strategy. We have to make sure we are doing something that society knows about and is interested in. Education: making sure we share our knowledge in a way which is understandable. Detector developments. Technology transfer. Work with industry. Making sure the byproducts of our activities can also be used for society. It’s a much wider view.

    LB: What is your role in this process?
    HA: The role of the secretary of the strategy is to organize the process and to chair the discussions so that there is an orderly process. At this stage, we have one year to prepare all the elements of the process that are needed—i.e. to collect the input. In the near future we will have to nominate people for the physics preparatory group that will help us organize the open symposium, which is basically the equivalent of a town-hall meeting.

    The hope is that if it’s well organized and we can reach a consensus, especially on the most important aspects, the outcome will come from the community. We have to make sure through interaction with the European community and the worldwide community that we aren’t forgetting anything. The more inputs we have, the better. It is very important that the process be open.

    The first year we debate the physics goals and try to organize the community around a possible plan. Then comes the process that is maybe a little shorter than a year, during which the constraints related to funding and interests of various national communities have to be integrated. I’m of course also hoping that we will get, as an input to the strategy discussions, some national roadmaps. It’s the role of the chair to keep this process flowing.

    LB: Can you tell us a little about your background and how you came to serve as the chair for European Strategy Update?
    HA: That’s a good question. I really don’t know. I did my PhD in 1978; I was one of the youngest PhDs of Warsaw University, thus I’ve spent 40 years in the field. That means that I have participated in at least five large experiments and at least two or three smaller projects. I have a very broad view—not necessarily a deep view—but a broad view of what’s happening.

    LB: There are major particle physics projects going on around the world, like DUNE in the US and Belle II in Japan. How much will the panel look beyond Europe to coordinate activities, and how will it incorporate feedback from scientists on those projects?

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    KEK Belle 2 detector, in Tsukuba, Ibaraki Prefecture, Japan

    HA: This is one of the issues that was very much discussed during my visit. We shouldn’t try to organize the whole world—in fact, a little bit of competition is very healthy. And complementarity is also very important.

    At the physics-level discussions, we’ll make sure that we have representatives from the United States and other countries so we are provided with all the information. As I was discussing with many people here, if there are ideas, experiments or existing collaborations which already include European partners, then of course, there is no issue [because the European partners will provide input to the strategy].

    LB: How do you see Europe working with Asia, in particular China, which has ambitions for a major collider?
    HA: Collaboration is very important, and at the global level we have to find the right balance between competition, which is stimulating, and complementarity. So we’re very much hoping to have one representative from China in the physics preparatory group, because China seems to have ambitions to realize some of the projects which have been discussed. And I’m not talking only about the equivalent of [the Future Circular Collider]; they are also thinking about an [electron-positron] circular collider, and there are also other projects that could potentially be realized in China. I also think that if the Chinese community decides on one of these projects, it may need contributions from around the world. Funding is an important aspect for any future project, but it is also important to reach a critical mass of expertise, especially for large research infrastructures.

    LB: This is a huge effort. What are some of the benefits and challenges of meeting with physicists from across Europe to come up with a single plan?
    HA: The benefits are obvious. The more input we have, the fuller the picture we have, and the more likely we are to converge on something that satisfies maybe not everybody, but at least the majority—which I think is very important for a good feeling in the community.

    The challenges are also obvious. On one hand, we rely very much on individuals and their creative ideas. These are usually the people who also happen to be the big pushers and tend to generate most controversies. So we will have to find a balance to keep the process interesting but constructive. There is no doubt that there will be passionate and exciting discussions that will need to happen; this is part of the process. There would be no point in only discussing issues on which we all agree.

    The various physics communities, in the ideal situation, get organized. We have the neutrino community, [electron-positron collider] community, precision measurements community, the axion community—and here you can see all kinds of divisions. But if these communities can get organized and come up with what one could call their own white paper, or what I would call a 10-page proposal, of how various projects could be lined up, and what would be the advantages or disadvantages of such an approach, then the job will be very easy.

    LB: And that input is what you’re aiming to get by December 2018?
    HA: Yes, yes.

    LB: How far does the strategy look out?
    HA: It doesn’t have an end date. This is why one of the requests for the input is for people to estimate the time scale—how much time would be needed to prepare and to realize the project. This will allow us to build a timeline.

    We have at present a large project that is approved: the high-luminosity LHC. This will keep an important part of our community busy for the next 10 to 20 years. But will the entire community remain fully committed for the whole duration of the program if there are no major discoveries?

    I’m not sure that we can be fed intellectually by one project. I think we need more than one. There’s a diversity program—diversity in the sense of trying to maximize the physics output by asking questions which can be answered with the existing facilities. Maybe this is the time to pause and diversify while waiting for the next big step.

    LB: Do you see any particular topics that you think are likely to come up in the discussion?
    HA: There are many questions on the table. For example, should we go for a proton-proton or an [electron-positron] program? There are, for instance, voices advocating for a dedicated Higgs factory, which would allow us to make measurements of the Higgs properties to a precision that would be extremely hard to achieve at the LHC. So we will have to discuss if the next machine should be an [electron-positron] machine and check whether it is realistic and on what time scale.

    One of the subjects that I’m pretty sure will come up as well is about pushing the accelerating technologies. Are we getting to the limit of what we can do with the existing technologies, and is it time to think about something else?

    To learn more about the European Strategy Update for Particle Physics, watch Abramowicz’s colloquium at Fermilab.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 5:55 pm on June 6, 2018 Permalink | Reply
    Tags: , Energy-Energy Correlation, , , , Symmetry Magazine, Video   

    From Symmetry: “We’re going to need a bigger blackboard” 

    Symmetry Mag
    From Symmetry

    06/06/18
    Farrin Abbott
    Manuel Gnida

    1
    Farrin Abbott, SLAC National Accelerator Laboratory

    Watch SLAC theorist Lance Dixon write out a new formula that will contribute to a better understanding of certain particle collisions.

    Physicists on experiments at the Large Hadron Collider study the results of high-energy particle collisions, often searching for surprises that their formulas don’t predict. Finding such a surprise could lead to the discovery of new particles, properties or forces.

    One of the formulas they use to predict the outcome of collisions is the EEC, which stands for Energy-Energy Correlation. The EEC measures how much energy in the form of particles goes into two detectors placed at a specific angle to one another.

    A group including theorist Lance Dixon of the US Department of Energy’s SLAC National Accelerator Laboratory and former postdoc Hua Xing Zhu recently figured out the formula for the biggest correction to EEC in decades.

    It’s a formula their paper calls “remarkably simple.” For the video below, Dixon offered to write it down.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:57 pm on May 8, 2018 Permalink | Reply
    Tags: , , , , , , Symmetry Magazine,   

    From Symmetry: “Leveling the playing field” 

    Symmetry Mag
    From Symmetry

    1
    Photo by Eleanor Starkman

    05/08/18
    Ali Sundermier

    [When I read this article, my first reaction was that this is all worthless. I have been running a series in this blog which highlights “Women in STEM” in all of the phases that the expression implies. The simple fact is that there is and continues to be and will continue to be gender bias in the physical sciences (and probably elsewhere, but this is my area of choice). This is certainly unfair to women, but it is also unfair to all of mankind. We are losing a lot of great and powerful minds and voices as we try to push the future of knowledge and quality of life for all. So I am doing the post. But in all fields men need to call on and respect women if things are to improve. I personally see no evidence of this. As long as women only get to talk to women there will be no progress.]

    Conferences for Undergraduate Women in Physics aims to encourage more women and gender minorities to pursue careers in physics and improve diversity in the field.

    Nicole Pfiester, an engineering grad student at Tufts University, says she has been interested in physics since she was a child. She says she loves learning how things work, and physics provides a foundation for doing just that.

    But when Pfiester began pursuing a degree in physics as an undergraduate at Purdue University in 2006, she had a hard time feeling like she belonged in the male-dominated field.

    “In a class of about 30 physics students,” she says, “I think two of us were women. I just always stood out. I was kind of shy back then and much more inclined to open up to other women than I was to men, especially in study groups. Not being around people I could relate to, while it didn’t make things impossible, definitely made things more difficult.”

    In 2008, two years into her undergraduate career, Pfiester attended a conference at the University of Michigan that was designed to address this very issue. The meeting was part of the Conferences for Undergraduate Women in Physics, or CUWiP, a collection of annual three-day regional conferences to give undergraduate women a sense of belonging and motivate them to continue in the field.

    Pfiester says it was amazing to see so many female physicists in the same room and to learn that they had all gone through similar experiences. It inspired her and the other students she was with to start their own Women in Physics chapter at Purdue. Since then, the school has hosted two separate CUWiP events, in 2011 and 2015.

    “Just seeing that there are other people like you doing what it is you want to do is really powerful,” Pfiester says. “It can really help you get through some difficult moments where it’s really easy, especially in college, to feel like you don’t belong. When you see other people experiencing the same struggles and, even more importantly, you see role models who look and talk like you, you realize that this is something you can do, too. I always left those conferences really energized and ready to get back into it.”

    CUWiP was founded in 2006 when two graduate students at the University of Southern California realized that only 21 percent of US undergraduates in physics were women, a percentage that dropped even further in physics with career progression. In the 12 years since then, the percentage of undergraduate physics degrees going to women in the US has not grown, but CUWiP has. What began as one conference with 27 attendees has developed into a string of conferences held at sites across the country, as well as in Canada and the UK, with more than 1500 attendees per year. Since the American Physical Society took the conference under its umbrella in 2012, the number of participants has continued to grow every year.

    The conferences are supported by the National Science Foundation, the Department of Energy and the host institutions. Most student transportation to the conferences is almost covered by the students’ home institutions, and APS provides extensive administrative support. In addition, local organizing committees contribute a significant volunteer effort.

    “We want to provide women, gender minorities and anyone who attends the conference access to information and resources that are going to help them continue in science careers,” says Pearl Sandick, a dark-matter physicist at the University of Utah and chair of the National Organizing Committee for CUWiP.

    Some of the goals of the conference, Sandick says, are to make sure people leave with a greater sense of community, identify themselves more as physicists, become more aware of gender issues in physics, and feel valued and respected in their field. They accomplish this through workshops and panels featuring accomplished female physicists in a broad range of professions.

    2
    Before the beginning of the shared video keynote talk, attendees at each CUWiP site cheer and wave on video. This gives a sense of the national scale of the conference and the huge number of people involved.
    Courtesy of Columbia University

    “Often students come to the conference and are very discouraged,” says past chair Daniela Bortoletto, a high-energy physicist at the University of Oxford who organizes CUWiP in the UK. “But then they meet these extremely accomplished scientists who tell the stories of their lives, and they learn that everybody struggles at different steps, everybody gets discouraged at some point, and there are ups and downs in everyone’s careers. I think it’s valuable to see that. The students walk out of the conference with a lot more confidence.”

    Through CUWiP, the organizers hope to equip students to make informed decisions about their education and expose them to the kinds of career opportunities that are open to them as physics majors, whether it means going to grad school or going into industry or science policy.

    “Not every student in physics is aware that physicists do all kinds of things,” says Kate Scholberg, a neutrino physicist at Duke and past chair. “Everybody who has been a physics undergrad gets the question, ‘What are you going to do with that?’ We want to show students there’s a lot more out there than grad school and help them expand their professional networks.”

    They also reach back to try to make conditions better for the next generations of physicists.

    At the 2018 conference, Hope Marks, now a senior at Utah State University majoring in physics, participated in a workshop in which she wrote a letter to her high school physics teacher, who she says really sparked her interest in the field.

    “I really liked the experiments we did and talking about some of the modern discoveries of physics,” she says. “I loved how physics allows us to explore the world from particles even smaller than atoms to literally the entire universe.”

    The workshop was meant to encourage high school science and math teachers to support women in their classes.

    One of the challenges to organizing the conferences, says Pat Burchat, an observational cosmologist at Stanford University and past chair, is to build experiences that are engaging and accessible for undergraduate women.

    “The tendency of organizers is naturally to think about the kinds of conferences they go to,” says Burchat says, “which usually consist of a bunch of research talks, often full of people sitting passively listening to someone talk. We want to make sure CUWiP consists of a lot of interactive sessions and workshops to keep the students engaged.”

    Candace Bryan, a physics major at the University of Utah who has wanted to be an astronomer since elementary school, says one of the most encouraging parts of the conference was learning about imposter syndrome, which occurs when someone believes that they have made it to where they are only by chance and don’t feel deserving of their achievements.

    “Science can be such an intimidating field,” she says. “It was the first time I’d ever heard that phrase, and it was really freeing to hear about it and know that so many others felt the same way. Every single person in that room raised their hand when they asked, ‘Who here has experienced imposter syndrome?’ That was really powerful. It helped me to try to move past that and improve awareness.”

    Women feeling imposter syndrome sometimes interpret their struggles as a sign that they don’t belong in physics, Bryan says.

    “It’s important to support women in physics and make sure they know there are other women out there who are struggling with the same things,” she says.

    “It was really inspirational for everyone to see how far they had come and receive encouragement to keep going. It was really nice to have that feeling after conference of ‘I can go to that class and kill it,’ or ‘I can take that test and not feel like I’m going to fail.’ And if you do fail, it’s OK, because everyone else has at some point. The important thing is to keep going.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 4:40 pm on May 6, 2018 Permalink | Reply
    Tags: , , , , LUX/Dark matter experiment at SURF, Symmetry Magazine, ,   

    From Symmetry: “The origins of dark matter” 

    Symmetry Mag
    From Symmetry

    11/08/16 [Just brought forward in social media]
    Matthew R. Francis

    1
    Artwork by Sandbox Studio, Chicago with Corinne Mucha

    [Because this article is well over a year old, I have updated it with Dark Matter experiments and also included a section on the origins of Dark Matter research by Vera Rubin and Fritz Zicky.]

    Dark Matter Research

    Caterpillar Project A Milky-Way-size dark-matter halo and its subhalos circled, an enormous suite of simulations . Griffen et al. 2016

    Milky Way Dark Matter Halo Credit ESO L. Calçada


    Dark matter halo. Image credit: Virgo consortium / A. Amblard / ESA

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LUX/Dark matter experiment at SURF

    Edelweiss Dark Matter Experiment, located at the Modane Underground Laboratory in France

    Transitions are everywhere we look. Water freezes, melts, or boils; chemical bonds break and form to make new substances out of different arrangements of atoms. The universe itself went through major transitions in early times. New particles were created and destroyed continually until things cooled enough to let them survive. Those particles include ones we know about, such as the Higgs boson or the top quark. But they could also include dark matter, invisible particles which we presently know only because of their gravitational effects. In cosmic terms, dark matter particles could be a “thermal relic,” forged in the hot early universe and then left behind during the transitions to more moderate later eras. One of these transitions, known as “freeze-out,” changed the nature of the whole universe.

    The hot cosmic freezer

    On average, today’s universe is a pretty boring place. If you pick a random spot in the cosmos, it’s far more likely to be in intergalactic space than, say, the heart of a star or even inside an alien solar system. That spot is probably cold, dark and quiet. The same wasn’t true for a random spot shortly after the Big Bang. “The universe was so hot that particles were being produced from photons smashing into other photons, of photons hitting electrons, and electrons hitting positrons and producing these very heavy particles,” says Matthew Buckley of Rutgers University. The entire cosmos was a particle-smashing party, but parties aren’t meant to last. This one lasted only a trillionth of a second. After that came the cosmic freeze-out. During the freeze-out, the universe expanded and cooled enough for particles to collide far less frequently and catastrophically. “One of these massive particles floating through the universe is finding fewer and fewer antimatter versions of itself to collide with and annihilate,” Buckley says. “Eventually the universe would get large enough and cold enough that the rate of production and the rate of annihilation basically goes to zero, and you just a relic abundance, these few particles that are floating out there lonely in space.” Many physicists think dark matter is a thermal relic, created in huge numbers in before the cosmos was a half-second old and lingering today because it barely interacts with any other particle.

    A WIMPy miracle

    One reason to think of dark matter as a thermal relic is an interesting coincidence known as the “WIMP miracle.” WIMP stands for “weakly-interacting massive particle,” and WIMPs are the most widely accepted candidates for dark matter. Theory says WIMPs are likely heavier than protons and interact via the weak force, or at least interactions related to the weak force. The last bit is important, because freeze-out for a specific particle depends on what forces affect it and the mass of the particle. Thermal relics made by the weak force were born early in the universe’s history because particles need to be jammed in tight for the weak force, which only works across short distances, to be a factor.

    “If dark matter is a thermal relic, you can calculate how big the interaction [between dark matter particles] needs to be,” Buckley says. Both the primordial light known as the cosmic microwave background [CMB] and the behavior of galaxies tell us that most dark matter must be slow-moving (“cold” in the language of physics).

    COBE CMB


    NASA/COBE 1989 to 1993.


    Cosmic Microwave Background NASA/WMAP


    NASA/WMAP 2001 to 2010


    CMB per ESA/Planck


    ESA/Planck 2009 to 2013

    That means interactions between dark matter particles must be low in strength. “Through what is perhaps a very deep fact about the universe,” Buckley says, “that interaction turns out to be the strength of what we know as the weak nuclear force.” That’s the WIMP miracle: The numbers are perfect to make just the right amount of WIMPy matter. The big catch, though, is that experiments haven’t found any WIMPs yet.

    It’s too soon to say WIMPs don’t exist, but it does rule out some of the simpler theoretical predictions about them.

    Ultimately, the WIMP miracle could just be a coincidence. Instead of the weak force, dark matter could involve a new force of nature that doesn’t affect ordinary matter strongly enough to detect. In that scenario, says Jessie Shelton of the University of Illinois at Urbana-Champaign, “you could have thermal freeze-out, but the freeze-out is of dark matter to some other dark field instead of [something in] the Standard Model.” In that scenario, dark matter would still be a thermal relic but not a WIMP. For Shelton, Buckley, and many other physicists, the dark matter search is still full of possibilities. “We have really compelling reasons to look for thermal WIMPs,” Shelton says. “It’s worth remembering that this is only one tiny corner of a much broader space of possibilities.”

    Well, what about AXIONS?

    CERN CAST Axion Solar Telescope


    Inside the ADMX experiment hall at the University of Washington Credit Mark Stone U. of Washington

    Origins of Dark Matter Research

    Vera Rubin measuring spectra (Emilio Segre Visual Archives AIP SPL)

    Vera Florence Cooper Rubin was an American astronomer who pioneered work on galaxy rotation rates. She uncovered the discrepancy between the predicted angular motion of galaxies and the observed motion, by studying galactic rotation curves. This phenomenon became known as the galaxy rotation problem, and was evidence of the existence of dark matter. Although initially met with skepticism, Rubin’s results were confirmed over subsequent decades. Her legacy was described by The New York Times as “ushering in a Copernican-scale change” in cosmological theory.

    Fritz Zwicky, the Father of Dark Matter research.No image credit after long search

    Fritz Zwicky, a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical and observational astronomy. In 1933, Zwicky was the first to use the virial theorem to infer the existence of unseen dark matter, describing it as “dunkle Materie

    There was no Nobel award for either Rubin or Zwicky.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 9:52 pm on April 29, 2018 Permalink | Reply
    Tags: , , , , , , , , , , , Symmetry Magazine   

    From Symmetry : “Putting the puzzle together” 

    Symmetry Mag
    Symmetry

    [While this article was written for a journal specializing in Physics, everything in it is true for all Basic and Applied Science. Soemwhere in my archives is an article from Natural History Magazine by Stephen Jay Gould in which he states that many new scientific ideas arise out of the existence of the devices built by technicians for the last experimental project. So it will be with the HL-LHC and the ILC.]

    11/21/17 [in social media today]
    Ali Sundermier

    1
    Photos by Fermilab and CERN

    Successful physics collaborations rely on cooperation between people from many different disciplines.

    So, you want to start a physics experiment. Maybe you want to follow hints of an as yet unseen particle. Or maybe you want to learn something new about a mysterious process in the universe. Either way, your next step is to find people who can help you.

    In large science collaborations, such as the ATLAS and CMS experiments at the Large Hadron Collider; the Deep Underground Neutrino Experiment (DUNE); and Fermilab’s NOvA, hundreds to thousands of people spread out across many institutions and countries keep things operating smoothly. Whether they’re senior scientists, engineers, technicians or administrators, each of them has an important role to play.

    CERN/ATLAS detector

    CERN CMS detector

    LHC

    CERN/LHC Map

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    CERN LHC Tunnel

    CERN LHC particles

    FNAL NOvA Near Detector


    FNAL/NOvA experiment map

    Think of it like a jigsaw puzzle: This list will give you an idea about how their work fits together to create the big picture.

    Dreaming up the experiment

    Many particle physics experiments begin with a fundamental question. Why do objects have mass? Or, why is the universe made of matter?

    When scientists encounter these big, seemingly inscrutable questions, part of their job is to identify possible ways to answer them. A large part of this is breaking down the big questions into a program of smaller, answerable questions.

    In the case of the LHC, scientists who wondered about things such as undiscovered particles and the origin of mass designed a 27-kilometer particle collider and four giant detectors to learn more.

    Each scientist in a collaboration brings their own unique perspective and skill set to the table, whether it’s providing an understanding of the physics or offering expertise in operations or detector design.


    CERN/ALICE Detector

    CERN/LHCb detector

    (ATLAS and CMS detectors are depicted above.]

    Perfecting the design

    Once scientists have an idea about the experiment they want to do and the approach they want to take, it’s the job of the engineers to turn the concepts into pieces of hardware that can be built, function and meet the experiment’s requirements.

    For example, engineers might have to figure out how the experiment should be supported mechanically or how to connect all the electrical systems and make signals available in a detector.

    In the case of NOvA [depicted above], which investigates neutrino oscillations, scientists needed a detector that was huge and free of dense materials, which made conventional construction techniques unworkable. They had to work with engineers who could understand plastic as a building material so they could be confident about using it to build a gigantic, free-standing structure that fit the requirements.

    Keeping things running

    Technicians come in when the experimental apparatus and instrumentation are being built and often have complementary knowledge about what they’re working on. They build the hardware and coordinate the integration of components. It’s their work that, in the end, pulls everything together so the experiment functions.

    Once the experiment is built, technicians are responsible for keeping everything humming along at top performance. When physicists notice things going wrong with the detectors, the technicians usually have first eyes on it. It’s a vital task, since every second counts when it comes to collecting data.

    Doing the heavy lifting

    When designing and constructing the experiment, the scientists also recruit postdocs and grad students, who do the bulk of the data analysis.

    Grad students, who are still working on their PhDs, have to balance their own coursework with the real-world experiment, learning their way around running simulations, analyzing data and developing algorithms. They also make sure that every part of the detector is working up to par. In addition, they may work in instrumentation, developing new instruments and electronics.

    Postdocs, on the other hand, have already worked on experiments and obtained their PhDs, so they typically assume more of a leadership role in these collaborations. Part of their role is to guide the grad students in a sort of apprenticeship.

    Postdocs are often in charge of certain types of analysis or detector operations. Because they’ve worked on previous experiments, they have a tool kit and experience to draw on to solve problems when they crop up.

    Postdocs and grad students often work with technicians and engineers to ensure everything is properly built.

    Making the data accessible

    The LHC produces about 25 petabytes of data every year, or 25 billion megabytes. If the average size of an MP3 is about one megabyte per minute, then it would take almost 50,000 years to play 25 petabytes of songs. In physics collaborations, computer scientists and engineers have to organize the computing networks to ensure against bottlenecks or traffic jams when this massive amount of data is shared.

    They also maintain the software framework, which takes care of data handling and archiving. Say a scientist wants to know what happened on Feb. 27, 2015, at 3 a.m. Computing experts have to be able to go into the data catalogue and find, among the petabytes of data, where that event is stored.

    Sorting out the logistics

    One often overlooked group is the administrators.

    It’s up to the administrators to sequence all the different projects so they get the funds they need to make progress. They sort the logistics to make sure the right people are in the right places working on the right things.

    Administrators manage a group of people who are constantly coming and going. Is someone traveling to a site from a different institution? The administrators make sure that people get connected, work out itineraries and schedule where visiting scientists will live and work.

    Administrators also organize collaboration meetings, transfer money, and procure and ship equipment.

    Translating discoveries to the public

    While every single person involved in an experiment has a responsibility to effectively communicate with others, it can be challenging to communicate about research in a way that’s relatable to people from different backgrounds. That’s where the professional communicators come in.

    Communicators can translate a paper full of jargon and complicated science into a fascinating story that the rest of the world can get excited about.

    In addition to doing outreach for the public and writing press releases and pitching stories for the media, communicators offer coaching to people in a scientific collaboration on how to relay the science to a general audience, which is important for generating public interest. [Everyone involved need to remember that all of this work is publicly funded with tax dollars, except in places like China where it is virtually the same thing.]

    [One of the main reasons I started this blog was that I found out that 30% of the scientists on the LHC are USA scientists and the US press does not write about science except the rare person like Dennis Overbye of the New York Times. I had seen the PBS video Creation of the Universe by Timothy Ferris (music by Brian Eno); The PBS video The Atom Smashers, centered on but not limited to the Tevatron at Fermilab and hints of what was to come in Europe in stead of Waxahachie, Texas; and The Big Bang Machine, with (Sir) Brian Cox, all about the LHC, with a nod back to the Tevatron. Someone at Quantum Diaries put me on to the Greybook which lists every institution in the world processing data from the LHC. I collected as much of their social media as I could and that was my start. Of course by now my source list has grown considerably and my subjects have also increased.]

    Fitting the pieces

    Now that you know many of the pieces that must fall into place for a large physics collaboration to be successful, also know that none of these roles is performed in a vacuum. For an experiment to work, there must be a synergy of tasks: Each relies on the success of the others. Now go start that experiment!

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:59 pm on April 29, 2018 Permalink | Reply
    Tags: , Anything to declare?, , , , , , Symmetry Magazine, Transporting valuable cargo one piece at a time   

    From Symmetry and FNAL: “Anything to declare?” 

    Symmetry Mag
    Symmetry

    01/05/17 [Just brought forward now in social media]
    Sarah Charley

    1
    A scientist at CERN removes a delicate half-disk of pixels from its custom-made box. The box was designed to fit snugly in an airplane seat. Photo courtesy of John Conway

    Sometimes being a physicist means giving detector parts the window seat.

    John Conway knows the exact width of airplane aisles (15 inches). He also personally knows the Transportation Security Administration operations manager at Chicago’s O’Hare Airport. That’s because Conway has spent the last decade transporting extremely sensitive detector equipment in commercial airline cabins.

    “We have a long history of shipping particle detectors through commercial carriers and having them arrive broken,” says Conway, who is a physicist at the University of California, Davis. “So in 2007 we decided to start carrying them ourselves. Our equipment is our baby, so who better to transport it than the people whose work depends on it?”

    Their instrument isn’t musical, but it’s just as fragile and irreplaceable as a vintage Italian cello, and it travels the same way. Members of the collaboration for the CMS experiment at CERN research center tested different approaches for shipping the instrument by embedding accelerometers in the packages.

    CERN CMS Tracker for HL-LHC

    Their best method for safety and cost-effectiveness? Reserving a seat on the plane for the delicate cargo.

    In November Conway accompanied parts of the new CMS pixel detector from the Department of Energy’s Fermi National Accelerator Laboratory in Chicago to CERN in Geneva. [See lead image.]The pixels are very thin silicon chips mounted inside a long cylindrical tube. This new part will sit in the heart of the CMS experiment and record data from the high-energy particle collisions generated by the Large Hadron Collider.

    “It functions like the sensor inside a digital camera,” Conway said, “except it has 45 megapixels and takes 40 million pictures every second.”

    Scientists and engineers assembled and tested these delicate silicon disks at Fermilab before Conway and two colleagues escorted them to Geneva. The development and construction of the component pieces took place at Fermilab and universities around the United States.

    Conway and his colleagues reserved each custom-made container its own economy seat and then accompanied these precious packages through check-in, security and all the way to their final destination at CERN. And although these packages did not leave Fermilab through the shipping department, each carried its own official paperwork.

    “We’d get a lot of weird looks when rolling them onto the airplane,” Conway says. “One time the flight crew kept joking that we were transporting dinosaur eggs.”

    After four trips by three people across the Atlantic, all 12 components of the US-built pixel detectors are at CERN and ready for integration with their European counterparts. This winter the completed new pixel detector will replace its time-worn predecessor currently inside the CMS detector.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 10:17 pm on April 25, 2018 Permalink | Reply
    Tags: , , , , , SuperKEKB Belle II collider, Symmetry Magazine   

    From Symmetry: “First collisions at Belle II” 

    Symmetry Mag
    Symmetry

    04/25/18
    Sarah Lawhun

    KEK SuperKEKB accelerator

    SuperKEKB accelerator Belle II Credit KEK

    The Japan-based experiment is one step closer to answering mystifying questions about antimatter.

    For the first time, the SuperKEKB collider at the KEK laboratory in Tsukuba, Japan, is smashing together particles at the heart of a giant detector called Belle II.

    “These first collisions represent a moment that all of us at Belle II have been looking forward to for a long time,” says Elisabetta Prencipe, a scientist at the German research center Forschungszentrum Juelich who works on particle tracking software and statistical analyses for Belle II. “It’s a step forward to opening a new door to the universe and our understanding of it.”

    The project looks for potential differences between matter and its mirror-world twin, antimatter, to figure out why our universe is dominated by just one of the pair. The experiment has been seven years in the making.

    During construction of the Belle II detector, the SuperKEKB accelerator was recommissioned to increase the number of particle collisions, a measure called its luminosity. Even now, the accelerator is preparing for the second part of this upgrade, which will take place in stages over the next 10 years. The upgrade will more tightly focus the beams and solidify SuperKEKB’s position as the highest-luminosity accelerator in the world.

    On March 21, SuperKEKB successfully stored an electron beam in the main ring, and on March 31 it stored a beam of positrons, the electron’s antimatter counterparts. With the two colliding beams in place, Belle II saw its first successful collisions today.

    2
    KEK/Belle II

    The beauty of quarks

    Scientists predict that antimatter and matter should have been created in equal amounts during the hot early stages of the big bang that formed our universe. When matter and antimatter meet, they annihilate in a burst of energy. Yet despite their presumed equal ratio, matter has clearly won the fight, and now makes up everything we see around us. It is this confounding mystery that Belle II seeks to unravel.

    Belle II’s beauty lies in its ability to detect unimaginably minute debris from high-energy collisions between electrons and positrons—particles so small they aren’t made up of anything else. In this debris, scientists look for physics beyond what they currently know by comparing particles’ properties to their predictions. The detector is especially sensitive to how other fundamental particles called quarks decay. It can closely study both quark properties and the structure of hadrons: particles made of multiple quarks bound together tightly.

    At Belle II’s core, electrons and positrons collide at a high enough energy to create B-mesons, particles made of one matter and one antimatter quark. Scientists are particularly interested bottom quarks, also known as beauty quarks.

    Bottom quarks are produced along with charm quarks at the center of Belle II. Both are heftier cousins of up and down quarks, which make up all ordinary matter, including you and whatever device you’re using to read this article. The collisions also produce tau leptons, which are like massive electrons. All of these particles are seldom found in nature, and observing them can reveal new physics.

    Since B-mesons contain bottom quarks, which have diverse kinds of decays, scientists will use Belle II to observe the different meson decays. If a meson containing regular quarks decays differently than one containing their antimatter twins, this could help explain why the universe is full of matter.

    Bolstering Belle

    Belle II is the successor of earlier experiments used to produce B-mesons, Belle and BaBar.

    SLAC/Babar

    It will record about 40 times as many collisions as the original Belle. It’s also a tremendous collaboration between 25 countries, with 750 national and international physicists.

    “Every measurement we’ve made until this point and every hint of new physics is limited by statistics and by the amount of data we have,” says Tom Browder, professor at the University of Hawaii and spokesperson for Belle II. “It’s very clear that to find any new physics we need much more data.”

    With more collisions at the center of Belle II, scientists have more opportunities for an uncommon or unheard-of decay event to take place, giving them better insight into quarks’ behavior and how it factors into the universe’s creation.

    “With 40 times more collisions per second than the previous Belle experiment, we’ll be able to search for rare decays, possibly observe new particles, and try to answer still unsolved questions about the origin of the universe,” Prencipe says. “Many of us are quite excited because this could mean the start of a new era, where lots of data are expected, new detectors will be tested, and we have great possibilities to perform unique physics.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 7:44 pm on April 24, 2018 Permalink | Reply
    Tags: , “Newton was the first physicist” says Sylvester James Gates a physicist at Brown University, , Peter Woit - “When you go far enough back you really can’t tell who’s a physicist and who’s a mathematician”, , Riemannian geometry, Symmetry Magazine, The relationship between physics and mathematics goes back to the beginning of both subjects   

    From Symmetry: “The coevolution of physics and math” 

    Symmetry Mag
    Symmetry

    04/24/18
    Evelyn Lamb

    1
    Artwork by Sandbox Studio, Chicago

    Breakthroughs in physics sometimes require an assist from the field of mathematics—and vice versa.

    In 1912, Albert Einstein, then a 33-year-old theoretical physicist at the Eidgenössische Technische Hochschule in Zürich, was in the midst of developing an extension to his theory of special relativity.

    With special relativity, he had codified the relationship between the dimensions of space and time. Now, seven years later, he was trying to incorporate into his theory the effects of gravity. This feat—a revolution in physics that would supplant Isaac Newton’s law of universal gravitation and result in Einstein’s theory of general relativity—would require some new ideas.

    Fortunately, Einstein’s friend and collaborator Marcel Grossmann swooped in like a waiter bearing an exotic, appetizing delight (at least in a mathematician’s overactive imagination): Riemannian geometry.

    This mathematical framework, developed in the mid-19th century by German mathematician Bernhard Riemann, was something of a revolution itself. It represented a shift in mathematical thinking from viewing mathematical shapes as subsets of the three-dimensional space they lived in to thinking about their properties intrinsically. For example, a sphere can be described as the set of points in 3-dimensional space that lie exactly 1 unit away from a central point. But it can also be described as a 2-dimensional object that has particular curvature properties at every single point. This alternative definition isn’t terribly important for understanding the sphere itself but ends up being very useful with more complicated manifolds or higher-dimensional spaces.

    By Einstein’s time, the theory was still new enough that it hadn’t completely permeated through mathematics, but it happened to be exactly what Einstein needed. Riemannian geometry gave him the foundation he needed to formulate the precise equations of general relativity. Einstein and Grossmann were able to publish their work later that year.

    “It’s hard to imagine how he would have come up with relativity without help from mathematicians,” says Peter Woit, a theoretical physicist in the Mathematics Department at Columbia University.

    The story of general relativity could go to mathematicians’ heads. Here mathematics seems to be a benevolent patron, blessing the benighted world of physics with just the right equations at the right time.

    But of course the interplay between mathematics and physics is much more complicated than that. They weren’t even separate disciplines for most of recorded history. Ancient Greek, Egyptian and Babylonian mathematics took as an assumption the fact that we live in a world in which distance, time and gravity behave in a certain way.

    “Newton was the first physicist,” says Sylvester James Gates, a physicist at Brown University. “In order to reach the pinnacle, he had to invent a new piece of mathematics; it’s called calculus.”

    Calculus made some classical geometry problems easier to solve, but its foremost purpose to Newton was to give him a way to analyze the motion and change he observed in physics. In that story, mathematics is perhaps more of a butler, hired to help keep the affairs in order, than a savior.

    Even after physics and mathematics began their separate evolutionary paths, the disciplines were closely linked. “When you go far enough back, you really can’t tell who’s a physicist and who’s a mathematician,” Woit says. (As a mathematician, I was a bit scandalized the first time I saw Emmy Noether’s name attached to physics! I knew her primarily through abstract algebra.)

    Throughout the history of the two fields, mathematics and physics have each contributed important ideas to the other. Mathematician Hermann Weyl’s work on mathematical objects called Lie groups provided an important basis for understanding symmetry in quantum mechanics. In his 1930 book The Principles of Quantum Mechanics, theoretical physicist Paul Dirac introduced the Dirac delta function to help describe the concept in particle physics of a pointlike particle—anything so small that it would be modeled by a point in an idealized situation. A picture of the Dirac delta function looks like a horizontal line lying along the bottom of the x axis of a graph, at x=0, except at the place where it intersects with the y axis, where it explodes into a line pointing up to infinity. Dirac declared that the integral of this function, the measure of the area underneath it, was equal to 1. Strictly speaking, no such function exists, but Dirac’s use of the Dirac delta eventually spurred mathematician Laurent Schwartz to develop the theory of distributions in a mathematically rigorous way. Today distributions are extraordinarily useful in the mathematical fields of ordinary and partial differential equations.

    Though modern researchers focus their work more and more tightly, the line between physics and mathematics is still a blurry one. A physicist has won the Fields Medal, one of the most prestigious accolades in mathematics. And a mathematician, Maxim Kontsevich, has won the new Breakthrough Prizes in both mathematics and physics. One can attend seminar talks about quantum field theory, black holes, and string theory in both math and physics departments. Since 2011, the annual String Math conference has brought mathematicians and physicists together to work on the intersection of their fields in string theory and quantum field theory.

    String theory is perhaps the best recent example of the interplay between mathematics and physics, for reasons that eventually bring us back to Einstein and the question of gravity.

    String theory is a theoretical framework in which those pointlike particles Dirac was describing become one-dimensional objects called strings. Part of the theoretical model for those strings corresponds to gravitons, theoretical particles that carry the force of gravity.

    Most humans will tell you that we perceive the universe as having three spatial dimensions and one dimension of time. But string theory naturally lives in 10 dimensions. In 1984, as the number of physicists working on string theory ballooned, a group of researchers including Edward Witten, the physicist who was later awarded a Fields Medal, discovered that the extra six dimensions of string theory needed to be part of a space known as a Calabi-Yau manifold.

    When mathematicians joined the fray to try to figure out what structures these manifolds could have, physicists were hoping for just a few candidates. Instead, they found boatloads of Calabi-Yaus. Mathematicians still have not finished classifying them. They haven’t even determined whether their classification has a finite number of pieces.

    As mathematicians and physicists studied these spaces, they discovered an interesting duality between Calabi-Yau manifolds. Two manifolds that seem completely different can end up describing the same physics. This idea, called mirror symmetry, has blossomed in mathematics, leading to entire new research avenues. The framework of string theory has almost become a playground for mathematicians, yielding countless new avenues of exploration.

    Mina Aganagic, a theoretical physicist at the University of California, Berkeley, believes string theory and related topics will continue to provide these connections between physics and math.

    “In some sense, we’ve explored a very small part of string theory and a very small number of its predictions,” she says. Mathematicians and their focus on detailed rigorous proofs bring one point of view to the field, and physicists, with their tendency to prioritize intuitive understanding, bring another. “That’s what makes the relationship so satisfying.”

    The relationship between physics and mathematics goes back to the beginning of both subjects; as the fields have advanced, this relationship has gotten more and more tangled, a complicated tapestry. There is seemingly no end to the places where a well-placed set of tools for making calculations could help physicists, or where a probing question from physics could inspire mathematicians to create entirely new mathematical objects or theories.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 10:09 am on April 23, 2018 Permalink | Reply
    Tags: Art intimates physics, Artist Chris Henschke, Symmetry Magazine   

    From Symmetry: “Art intimates physics” 

    Symmetry Mag
    Symmetry

    04/03/17
    Liz Kruesi

    1
    Mark Ashkenazy

    Artist Chris Henschke’s latest piece inspired by particle physics mixes constancy with unpredictability, the natural with the synthetic.

    Artist Chris Henschke has spent more than a decade exploring the intersection of art and physics. His pieces bring invisible properties and theoretical concepts to light through still images, sound and video.

    His latest piece, called “Song of the Phenomena,” gives new life to a retired piece of equipment once used by a long-time collaborator of Henschke, University of Melbourne and Australian Synchrotron physicist Mark Boland.

    Crossing paths

    The story of “Song of the Phenomena” begins in the 1990s. In 1991, Henschke enrolled in the University of Melbourne to study science, but he turned to sound design instead. Boland entered the same university to study physics.

    Personal computers were just entering the market. Sound designers and animators began coding basic programs, and Henschke joined in. “I was always interested in making sounds and music, interested in light and art and physics and nature and how it all combines—either in our heads or the devices that mediate between us and nature,” he says.

    Boland completed his thesis in physics at the Australian Radiation Laboratory (now called the Australian Radiation Protection and Nuclear Safety Agency). He was testing a new type of electron detector in a linear accelerator, or linac. The linac used radio waves to guide electrons through a series of accelerator cavities, which imparted more and more energy to the particles as they moved through.

    That particular linac spent more than 20 years with the Australian Radiation Protection and Nuclear Safety Agency, where medical physics professionals used it to accelerate electrons to different energies to create calibration standards for radiation oncology treatments. Once they no longer needed it, Boland’s former advisor contacted him to ask if he’d like the accelerator or any of its still-working parts. He said yes, though he was unsure what he would do with it.

    An artist’s view

    In 2007 Henschke came to the Australian Synchrotron as part of an artist-in-residence program.


    Australian Synchrotron

    Boland was familiar with his artwork; he had seen Henschke’s first piece exploring particle physics in the pages of Symmetry. Boland grew up with an appreciation for art; he says his parents made sure of that by “dragging” him through many galleries in his youth.

    When Henschke and Boland met, they got into an hours-long conversation about physics. “We hit it off, we resonated,” Boland says, “and we’ve been working together ever since.”

    Since that first residency program, Henschke has spent significant time at the Australian Synchrotron facility and at CERN European research center and has taken shorter trips to the DESY German national research center.

    His process of creating artwork echoes the scientific process and the setup of an experiment, Boland says. Henschke thinks through the role that each piece of the artwork plays. Everything is where it is for a reason.

    “He’s a perfectionist, he doesn’t settle for second best,” Boland says. “He has the same level of professionalism and tenacity as an artist as a physicist does. It’s as if there’s a five-sigma quality test on his work as well.”

    Once accelerator, now art

    Boland mentioned the linac he had to Henschke during a conversation in early 2016. “Chris ran with it,” Boland says. “He took it and made it into his installation.”

    Henschke discovered the machine hums at 220 hertz—the musical note of A—as it produces its resonant waves. “In a sense, particle accelerators are gigantic, high-energy synthesizers because they are creating high-energy waves at very specific frequencies and amplitudes,” Henschke says.

    Henschke explored different aspects of the machine, still unsure how each part would come together as a final piece of art. “I have to let it speak to me, I have to let it speak for itself,” he says.

    Finally it dawned on him; the art could be an echo of the accelerator’s past.

    The accelerator no longer accelerates electrons. Instead Henschke feeds it a steady supply of electrons and their antimatter partners, positrons. He does this by placing it beside a pile of bananas, which release the particles as their potassium decays. (Using decaying fruit was a nod to Dutch still-life vanitas paintings, Henschke says.)

    Observers cannot see the electrons and positrons in the piece, but they can hear them. Henschke ensured this by adding a Geiger counter, which emits a chirp each time it detects a particle.

    Visitors can also hear the accelerator itself. Henschke attached speakers and pumped up the sound of the machine’s natural hum with a stereo amp (a bit too much at first; they blew up an oscilloscope they were using to measure the frequency). He used an AM radio coil to amplify the sound of the accelerator’s electromagnetic field.

    “Song of the Phenomena” plays upon resonance, amplification and decay, Henschke says. “It creates this tension between the constant hum of the device versus the unpredictability of the subatomic emission.”

    The idea of playing with the analogy between the linac’s resonance and sound resonance is one that Australian Synchrotron Director Andrew Peele appreciates. “A lot of science communication is about how you find analogies that people can engage with, and this is a great example,” Peele says.

    Henschke displayed “Song of the Phenomena” at the Royal Melbourne Institute of Technology Gallery from November 17, 2016, to February 18, 2017. Since then, the apparatus has returned to the Australian Synchrotron, where it sits in a vast, open room where some of the facility’s synchrotron beamline stations used to stand. Scientists meet nearby for a weekly social coffee break.

    Henschke is currently writing his thesis for his PhD in experimental art (with Boland as his advisor). In his next project, he hopes to tackle the subject of quantum entanglement.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    Symmetry is a joint Fermilab/SLAC publication.


     
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