Physics

Physicist’s dissertation gets top marks from American Physical Society

Anonymous — Fri, 24 May 2024 15:05:33 +0000

Physicist’s dissertation gets top marks from American Physical Society Anonymous (not verified) Fri, 05/24/2024 - 09:05

Blair Seidlitz, now a postdoctoral researcher at Columbia University, studied near-collisions of nuclear beams at the Large Hadron Collider in Switzerland, and he did so despite having severely limited vision

Blair Seidlitz, who earned his PhD in physics in 2022 from the �鶹��Ƶ, has won the American Physical Society (APS) Dissertation Award in Hadronic Physics for his dissertation, the society announced.

Seidlitz’s dissertation research was on the ATLAS Experiment of the Large Hadron Collider, hosted at the international CERN laboratory in Switzerland. His CU Boulder research group, led by Professors Dennis Perepelitsa and Jamie Nagle, works in experimental nuclear physics—it collides nuclear beams (“ions") at the LHC to study the fundamental forces of nature under extreme conditions.

The major advance of Seidlitz’s dissertation was to use these nuclear beams at the LHC in an unusual way. “He was interested in the processes not where the beams slam into each other … but instead the cases where the beams just barely miss each other,” Perepelitsa said.

CU Boulder physics PhD alum Blair Seidlitz won the American Physical Society (APS) Dissertation Award in Hadronic Physics for his dissertation research on the ATLAS Experiment of the Large Hadron Collider.

“It turns out that in these cases, a photon emitted by one ion can strike the other, and thus result in rare and unusual ‘photo-nuclear’ collisions …. The ATLAS detector was not set up to take this kind of data by default. So Blair had to do a lot of work to develop the ‘trigger’ (the algorithms that decide which data to even record), to get access to this rare dataset.”

Perepelitsa said this kind of work is unusual for a graduate student; many graduate students work with existing infrastructure or use well-established procedures in research like this. “But Blair really took his idea from the conception stage, to implementing it himself, and helping to deploy it in person during data-taking at CERN,” a bustling scientific community at which Seidlitz spent significant time.

Once Seidlitz had collected the data, he then did a very careful analysis, which necessitated developing some new methods because nobody had really done this kind of thing before, Perepelitsa added.

The surprising result was that these sparse “photo-nuclear” collisions exhibited a collective “flow” behavior among their produced particles—“something you might only expect in the collisions of large nuclei where there are many, many particles that are produced and interact.”

“His measurement has come at a time when the scientific community is asking big questions, such as: Just how few particles can one have to still exhibit many-body collective motion? Blair’s thesis work, by paving the way to experimentally access these unusual datasets, is addressing these open questions head on!”

Seidlitz is now a post-doctoral researcher at Columbia University. He still works at ATLAS, but he now also works at a new experiment at the Relativistic Heavy Ion Collider, in which Perepelitsa and Nagle’s group at CU is closely involved. “So we are pleased that we can continue to collaborate with Blair very closely,” Perepelitsa said.

Seidlitz said he hopes to build on his graduate school work. “There are actually distinct categories (or types) of photon-nucleus collisions. My thesis work did not sort the different types, but studied them as a whole. In principle, it should be possible to sort these, although it has never been done. That way, we could study the ‘flow’ properties of each type individually, which would be really interesting.”

Seidlitz said that he and his colleagues will be able to study these types of collisions at the Electron Ion Collider, which is scheduled to be completed in the 2030’s at Brookhaven National Laboratory (BNL) on Long Island, New York.

Seidlitz said he was surprised to win the APS dissertation award. “They called me while I was in the sPHENIX control room (an experiment at BNL). I don't usually pick up my phone, but it seemed to not be spam, and as fate would have it, it was an official from APS saying I had won.”

Seidlitz has charted a successful academic career even though he has Stargardt's disease, a rare form of macular degeneration that leaves him with approximately 1/20th the visual acuity of average people.

A wheel in the ATLAS detector of the Large Hadron Collider. Blair Seidlitz's dissertation research focused on near-collisions of nuclear beams in ATLAS. (Photo: CERN)

His vision posed many challenges, he said. “I guess the first challenge was learning as much as I could and getting through courses without being able to see the black board or projector, where I did most of my learning through textbooks.”

Seidlitz said disability service centers at CU Boulder and at his undergraduate institution, the University of Wisconsin, Madison, “really made it possible for me to succeed, from scanning old textbooks to make PDFs, to scanning students' homework so I could grade it when I was a TA and recommending assistive technology.”

Another challenge was finding a field of research that would work for him. “Because physics that revolves around particle accelerators is so big and complicated, large collaborations are formed and the work is shared. Some people build the detectors—something I could not do—and others set up data analysis and reconstruction, which is a lot of software to take the signals from individual detectors and turn it into a measurement of a photon with a particular momentum, for example,” Seidlitz explained, adding:

“This is something I can do! I would say there are still challenges day to day, but they are manageable, and I am very grateful that I am in a place where I can contribute and do valuable work.

Seidlitz grew up in Wisconsin and earned a BS in engineering physics from the University of Wisconsin, Madison. As an undergraduate, he conducted research in plasma physics with Cary Forest, applying optical emission spectroscopy techniques for measurements of the electron temperature in the Plasma Couette Experiment and the Madison Plasma Dynamo Experiment.

The American Physical Society is a nonprofit organization working to advance and diffuse the knowledge of physics through its research journals, scientific meetings and education, outreach, advocacy and international activities.

APS represents more than 50,000 members, including physicists in academia, national laboratories and industry in the United States and throughout the world.

Top image: The eight toroid magnets surrounding the calorimeter in the ATLAS detector. The calorimeter measures the energies of particles produced when protons collide in the center of the detector. (Photo: CERN)

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A Nobel laureate walks into a first-year physics class…

Anonymous — Fri, 19 Apr 2024 18:57:11 +0000

A Nobel laureate walks into a first-year physics class… Anonymous (not verified) Fri, 04/19/2024 - 12:57

Rachel Sauer

General Physics for Majors course designed by CU Boulder Professors Eric Cornell and Paul Beale shows students that the furthest reaches of science are built on fundamental concepts

The Nobel laureate was not feeling happy about his minus signs.

He stood back from the blackboard—yes, an actual blackboard on which he wrote with actual chalk—and considered the calculus he’d jokingly hyped just moments before with, “This is some of that real calculus sensation. This is why you sat through that whole calculus class: for this moment.”

His team teacher, a noted scientist who this year is marking 40 years teaching physics at the �鶹��Ƶ, called from the back of the classroom, “That’s right, Eric.”

Professors Paul Beale (left) and Eric Cornell prepare for a Tuesday morning PHYS 1125 class. (Photos: Rachel Sauer)

Advanced math is not always easy with an audience watching—in this case, about 85 first-year physics, astrophysics and engineering physics students in PHYS 1125, General Physics 2 for Majors.

It’s a class for students who know they want to pursue a field of physics and are newly starting out in it. And it’s taught by a Nobel laureate.

“I harken back to freshman physics every day of my life,” explains Eric Cornell, a CU Boulder professor adjoint of physics and 2001 Nobel Prize winner in physics for his work with Bose-Einstein condensates. “I’m in a Facebook group with people I met my freshman year in physics.”

In other words, there’s absolutely no reason a Nobel laureate shouldn’t teach first-year physics.

Basic, foundational concepts

Cornell and Paul Beale, a CU Boulder professor of physics, created the course six years ago, in part to help students interested in pursuing physics to find community and support among like-minded peers. While other introductory physics courses are open to all majors, this one is specifically for physics, astrophysics and engineering physics majors. Steven Pollock, a professor of physics, and Yuan Shi, an assistant professor of physics, in the fall taught the first half of the course, PHYS 1115, which was created by Professors Chuck Rogers and Shijie Zhong.

“We start from ground zero,” Beale says. “Most (of the students) have had some physics in high school, most have seen these ideas before—they know that same charges repel. But even students who have had really good high school physics classes, maybe even AP classes, we say, ‘That’s great! Take our class.’

“Being with other physics majors helps them relax and get immersed in the field. Everybody in there really wants to be in there.”

Professor Eric Cornell (center, striped shirt) answers student questions in the physics help room.

A cynic might ask, however, why a Nobel laureate would be teaching a first-year class. Shouldn’t they be, you know, spending their time in the furthest, most esoteric reaches of physics? Doing the kind of science only a handful of people on the planet can understand?

“I want to push back on that idea that the basic, foundational concepts of physics don’t have considerable charm of their own,” Cornell says. “This is really fun stuff, and one of the things I like about this course is it gets into really interesting things right away.”

“It’s also a hard class,” Beale adds. “The concepts are difficult, so the challenge for us is to do everything we can to make them approachable. (The students) have got to get them right even though they’re hard, because everything else in physics builds on what they learn here.”

Cornell and Beale designed the class not only with beginning physics students in mind, but learning assistants and graduate students as well.

“In a lot of schools, grad students—who might be just one year past undergrad—are thrown in the classroom and told, ‘Here, go teach,’” Cornell says. In this course, however, graduate students assist with weekly tutorials but meet with Beale and Colin West, an associate teaching professor of physics, before each one, because the skills of teaching need to be taught. The same is true for class learning assistants, who are undergraduate students who took the course the previous year.

Cornell and Beale also spend time in the physics help room each week, which is a space where students can drop by for help with anything physics related.

“I would say that we are a very good teaching department, and not just our graduate program,” Beale says. “This is your introduction to physics, and you’re either going to like it or not, so we put a lot of effort into the first years.”

“We’re always asking, ‘How do we do better teaching?’” Cornell adds. “People like Paul and me have the advantage of people in this department who have studied teaching and have tried approaches like using clickers, using a conversational approach, using hands-on demonstrations. There are ongoing discussions about how we can be teaching better.”

Physics with a purple crayon

Sometimes, better teaching means an apology: “It’s my sorry duty to apologize for all the sins of physicists who went before me, and electrical engineers. And Ben Franklin,” Cornell said, writing “sorry!!” on the blackboard and underlining it twice. “I’m here to apologize for this thing called ‘potential.’ The whole rest of your life you’re going to be thinking about electric potential. It’s unavoidable. Your intuition will overwhelm your minus-sign errors.

Professor Paul Beale (standing, blue sweater) walks around the classroom during PHYS 1125 to help students and answer questions.

“It’s a ‘sorry, but...’ though, which is another way to say, ‘Suck it up.’”

While Cornell pivoted to voltage, “a happier, friendlier term (than electric potential),” Beale walked slowly among the rows of seats, stopping to sit by students who had questions and prompt them toward their response on class-wide clicker questions.

Pranay Raj Poosa, a freshman majoring in astrophysics who hopes to study black holes and neutron stars, cites Cornell’s and Beale’s enthusiasm for physics and their personal, conversational approach to teaching as two of the reasons he likes the class: “The fun they generate makes my understanding crystal clear,” he said. “The first day of class, (Cornell) made a joke about himself, which I personally felt was clap-worthy.”

Poosa added that he was in “utter disbelief” when his advisor mentioned a Nobel laureate would be teaching the class.

For Min Wang, a sophomore majoring in physics and interested in theoretical neuroscience and writing science fiction, Cornell and Beale have shown her that “great minds are not the ones who are walking in front of others all the time. They always slow down and let the young generation be on their shoulders.

“Even though what Professor Cornell taught us is just a tiny piece of knowledge in his mind, he shows amazing patience to every student and shows us how profound even a little, tiny bit in physics can be. And since I have time conflicts with all the office hours, Professor Beale gives me a special office hour time according to my school schedule. It is after class and work time on Friday! They make me feel welcome in the world of physics.”

Wang noted that while learning physics is not without its pains, she doesn’t feel alone in tackling them because she is part of a “lovely and supportive physics community created by the professors.”

Which is good, because it was time to do “a very modest amount of algebra, the kind you could do with a purple crayon if you’ve got one,” Cornell said, explaining how they could figure capacitance between two metal plates and then telling the students, “I’m going to show you something which I think is very neat. It’s kind of an advanced idea, giving you a taste of physics to come.”

The key thing to remember? “The whole idea of physics is zooming all the way into what does matter and ignoring what doesn’t.”

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General Physics for Majors course designed by CU Boulder Professors Eric Cornell and Paul Beale shows students that the furthest reaches of science are built on fundamental concepts.

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Nobel Prize winner Andrea Ghez to give 53rd Gamow lecture

Anonymous — Wed, 21 Feb 2024 17:10:38 +0000

Nobel Prize winner Andrea Ghez to give 53rd Gamow lecture Anonymous (not verified) Wed, 02/21/2024 - 10:10

Astrophysicist who confirmed black hole at galaxy’s center to speak March 5 at CU Boulder

Andrea Ghez, recipient of the 2020 Nobel Prize in physics, will give the 53rd George Gamow Memorial Lecture March 5 at the �鶹��Ƶ.

Ghez, Lauren B. Leichtman and Arthur E. Levine Professor of Physics and Astronomy at UCLA, shared half of the prize with Reinhard Genzel of the University of California, Berkeley.

Andrea Ghez, 2020 Nobel Prize winner in physics, will give the 53rd George Gamow Memorial Lecture March 5 at the �鶹��Ƶ. (Photo: The Nobel Foundation)

The pair were recognized by the Nobel committee for their discovery of a “supermassive” black hole at the center of the Milky Way galaxy. Ghez, head of UCLA’s Galactic Center Group, solved the question, what exactly is “Sagittarius A*,” which was first detected as a mysterious radio signal in 1933.

“I see being a scientist as really fundamentally being a puzzle-solver,” Ghez said in 2021. “Putting together the pieces, trying to find the evidence, trying to see the bigger picture.”

If you go

What: 53rd George Gamow Memorial Lecture

Who: Andrea Ghez, recipient of the 2020 Nobel Prize in Physics

When: 7:30 p.m. Tuesday, March 5

Where: Macky Auditorium, �鶹��Ƶ campus

Tickets: Free and open to the public

Learn more

She helped develop a new technology to correct the distorting effects of Earth’s atmosphere. Gathering data from the world’s largest telescope system, the W. M. Keck Observatory in Hawaii, she and her team continue to plumb the depths of the galactic center 26,000 light years distant.

While Albert Einstein’s epochal work on relativity remains the best description of how gravity works, Ghez says it can’t account for gravity inside a black hole. Through what she calls “extreme astrophysics,” she seeks to go where the pioneering astrophysicist could not.

“Einstein’s right for now,” she said. “However, his theory is showing vulnerability. … At some point we will need to move … to a more comprehensive theory of gravity.”

A member of the National Academy of Sciences and author of a 2006 children’s book, “You Can Be a Woman Astronomer,” Ghez is widely recognized as a role model for young women.

“Seeing people who look like you, or are different from you, succeeding shows you that there’s an opportunity,” she said.

Top image: An artist's concept illustrating a supermassive black hole with millions to billions times the mass of fthe Sun. (Illustration: NASA/JPL-Caltech)

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Astrophysicist who confirmed black hole at galaxy’s center to speak March 5 at CU Boulder.

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Frank Oppenheimer, Robert’s brother, honed physics teaching at CU Boulder

Anonymous — Thu, 25 Jan 2024 16:05:40 +0000

Frank Oppenheimer, Robert’s brother, honed physics teaching at CU Boulder Anonymous (not verified) Thu, 01/25/2024 - 09:05

Rachel Sauer

In a little-known chapter of university history, the Manhattan Project scientist taught for several years in the Department of Physics, and his legacy appears in the fabric of the department

Al Bartlett, the legendary �鶹��Ƶ physics professor, was a judge for the combined Colorado-Wyoming high school science fair in the mid-1950s. One year at the awards banquet, he later recalled to author K.C. Cole, many of the winners suddenly were from Pagosa Springs High School.

Pagosa Springs? Where even was that? As each Pagosa winner was announced, the faces of students from bigger, more prestigious Denver high schools fell further, Bartlett recalled. Many of the Pagosa students were Hispanic, many from “ordinary origins” and many bussed to the competition by their science teacher.

As for that teacher, Bartlett would later learn it was someone with whom he shared a background—working on the Manhattan Project developing the atomic bomb. And someone who, within several years, would become his colleague in the CU Boulder Department of Physics.

Paul Beale, a CU Boulder professor of physics, remembers Bartlett describing how he asked someone about this new science teacher and was informed the gentleman’s name was “Oppen-something.”

Frank Oppenheimer (left) was played by Dylan Arnold (right) in Christopher Nolan's Oscar-nominated film Oppenheimer. (Frank Oppenheimer photo: Bettman Archive; Dylan Arnold photo: Universal Pictures)

Ahhh. Well, OK then, that explained it. Oppenheimer. Frank Oppenheimer, younger brother of J. Robert Oppenheimer, brilliant particle physicist, Manhattan Project scientist, blacklisted as a communist and, in a history not widely known, onetime CU Boulder faculty member.

Since the summer 2023 release of Christopher Nolan’s film Oppenheimer, which on Tuesday earned 13 Academy Award nominations, the surname has become popularly synonymous with science. While Robert may be the more famous brother—and the film’s subject, due to directing the Los Alamos Laboratory when the Manhattan Project was housed there—Frank’s scientific legacy runs similarly deep.

In the several years he taught physics at CU Boulder, Frank Oppenheimer not only made science exciting and accessible, but he initiated the creation of the Library of Experiments. This library allowed instructors greater freedom in tailoring physics instruction, getting away from the “do these steps and this should happen” approach, and allowing students hands-on learning.

There were no “black boxes, no gimmicks, no contrivances to make an experiment work in accordance with theory,” recalls Jerry Leigh, who was hired at CU Boulder to work with Oppenheimer on the Library of Experiments. “Students could apply textbook principles to an apparatus directly, and ‘see’ the principles contained therein.”

It was an exciting way to learn science, Leigh says, and Oppenheimer was excited about science.

A winding path

By the time Oppenheimer arrived at CU Boulder in 1959, he had already helped develop the bomb that ended World War II, been branded a communist, sold a Van Gogh painting to buy a ranch and guided a high school of fewer than 300 students to state science fair glory. Among other things, of course.

Following the war and his work on the Manhattan Project, Oppenheimer accepted a position teaching physics at the University of Minnesota. However, he was “outed” as a communist in a 1947 Washington Times-Herald article and eventually called before the House Un-American Activities Committee (HUAC) in 1949.

He initially denied any communist affiliation, but eventually testified that he and his wife, Jackie, had been members of the American Communist Party for about three years in the late 1930s, when they lived in California and were active in efforts to desegregate a public swimming pool in Pasadena.

As a result of his HUAC testimony, Oppenheimer was pressured to resign his position at the University of Minnesota, was denied his passport and could not get a job anywhere working in physics. He was understandably angry, and noted in a letter to his friend, esteemed physicist Robert Wilson, “At the moment it seems that all organizations that men create are either impotent or monsters."

However, admitting that he “acted badly” by not better explaining himself to the HUAC, Oppenheimer further wrote, “I think if one does not try to explain what one believes in and still pretends to be an intellectual, then soon one ceases to believe in anything."

Frank Oppenheimer demonstrates a gyroscope at Pagosa Springs High School (left) and uses a microscope in 1967. (Left photo: Stanely Fowler, Oppenheimer's former student; right photo: Bill Johnson/The Denver Post)

Oppenheimer’s father had been a passionate art collector and from him Oppenheimer inherited, among other works, the Van Gogh that he sold to buy a 1,500-acre ranch near Pagosa Springs in southern Colorado. Frank and Jackie, and their son and daughter, ranched cattle for about 10 years, becoming good neighbors and active in the community, Cole wrote in her book Something Incredibly Wonderful Happens: Frank Oppenheimer and His Astonishing Exploratorium.

When a teaching position opened at Pagosa Springs High School, Oppenheimer, who earned a PhD in physics from Caltech, seemed right for it but didn’t have state teaching credentials. The community, Cole wrote, was appalled that the state wouldn’t give him a license to teach, so he was granted temporary licensure while taking correspondence courses in education.

He wrote in a research paper for his credentials, “I am certain that mathematicians must frequently run into some object that they want to play with or investigate much as one is always tempted to play with magnets or gyroscopes or Silly Putty.” It foreshadowed his later work to help evolve science education so that it was fun, hands-on and playful.

Excited about teaching

Oppenheimer earned his full teaching credential in 1957 and at that point was teaching physics, chemistry, biology and general science in a community of about 850 people that hadn’t previously had a dedicated science teacher. Not long thereafter, Oppenheimer’s students began arriving at the University of Colorado and wowing their professors, physicist Hal Zirin told Cole.

In summer 1958, Oppenheimer and his family moved to Boulder in part so he could position himself for opportunities at CU. He helped develop a new National Science Foundation curriculum and taught in the Summer Institute for High School Physics Teachers. He also taught special physics classes throughout Jefferson County.

During this time, Cole wrote, Oppenheimer “realized that the teachers themselves had to be excited about the material and engaged in discovery or they'd never be able to inspire, or even adequately teach, their students.”

After returning to Pagosa Springs so his son could complete his sophomore year of high school, Oppenheimer’s strategy of positioning himself for entry into CU faculty paid off, and in 1959 he was offered a position as a research associate. His past in the American Communist Party continued haunting him, though, and several members of the Board of Regents attempted to block his appointment.

Fortunately, Wesley Brittin, who was then chair of the CU Boulder Department of Physics, was strongly on Oppenheimer’s side, showing tremendous courage in the face of intimidating opposition, Beale says. Brittin sought letters of recommendation from such esteemed physicists as Hans Bethe, George Gamow and Victor Weisskopf. During the Board of Regents meeting to determine Oppenheimer’s fate at CU, Bartlett and several of his physics colleagues waited anxiously outside the door, Bartlett recalled to Cole.

Oppenheimer became an associate professor in 1961 and a full professor in 1964.

[video:https://www.youtube.com/watch?v=xC2XWIWkZ8A&list=PLaWHFWu_46_xWlImHKbee4c5tDNTaWxcG&index=15]

While at CU Boulder, Frank Oppenheimer created a video series explaining the various experiments in the Library of Experiments. See the entire series here.

Building a Library of Experiments

Oppenheimer was already established in the physics faculty when Allan Franklin, now a professor emeritus, joined the faculty as a young scientist. Though he could easily have been in awe of the famous—some might say infamous—physicist, Franklin recalls Oppenheimer as kind and generous to an early career scientist.

“He invited us to his home on High Street in downtown Boulder,” Franklin remembers. “He was quite a modest guy, and I never remember him being bitter about how badly he’d been treated.”

Franklin recalls a friend telling him about complimenting Oppenheimer on the collection of art hanging on his living room walls, noting to Oppenheimer that a particular painting was “’the best copy of Picasso I’ve ever seen.’ And Frank says, ‘It’s not a copy.’”

Oppenheimer also never expressed a sense that he existed in his famous brother’s shadow, Franklin says: “J.R. was a theorist but Frank was experimental. He was really interested in teaching, and he completely revised our sophomore modern physics labs.”

Those revisions would evolve into the Library of Experiments, which created a “cafeteria” approach to physics experiments. Rather than every student in class doing the same experiments, a student could choose the required number of experiments that interested them the most.

Leigh recalls that Oppenheimer had clear ideas about what he wanted an experiment to be. “I was to assist teaching assistants with growing classes, devising and fabricating fixes for (Oppenheimer’s) often crudely built apparatus and repair lab documentation written hastily without editing,” Leigh says.

Learn more

CU Boulder has a broad history of recruiting former Los Alamos scientists. Former CU Boulder President Robert L. Stearns, through his work in a Pacific War Targeting unit, was assigned to the Atomic Bomb Targeting Committee in 1945, which may have been when he came in contact with Los Alamos physicists, mathematicians and scholars. After the war ended, David Hawkins and Al Bartlett came to CU Boulder in 1947 and 1950, respectively. But the real flow of former Los Alamos scientists came later, under presidents Ward Darley, Quigg Newton and George Smiley: George Gamow in 1956; Stanisław Ulam and Edward Condon in 1963; and Robert D. Richtmyer in 1964. These CU Boulder presidents were committed to bringing in quality faculty, regardless of criticism. In addition, after Sputnik and rising Congressional and grant support for space sciences, support for physics, mathematics and engineering at CU Boulder grew considerably.

—David Hays, University Libraries archivist

“At first, Frank was somewhat distant, but friendly. Students were grouped at each experiment in twos or threes, so Frank circulated among the groups and politely offered suggestions and asked challenging questions of students, yet never intruding or confronting them.

“Over time, Frank began to approach me saying, ‘There is something want to show you.’ He would demonstrate some apparatus, pointing out items in need of improvement. The first involved a Polaroid camera that was mounted on a heavy stand that was tilted to provide data. The motion being studied was sinusoidal, and tilting the camera abruptly changed the field of view so the data was often bad. So, I had a shop make a mount that changed the camera’s position sinusoidally. Data became perfect and Frank beamed with joy.”

In another experiment, a steel ball was held up by an electromagnet and then dropped, providing a measurement of Earth's gravitation. The ball often stuck to the magnet instead of falling, so Leigh glued a small fiber washer to the magnet and fixed the problem, “and Frank glowed with satisfaction,” Leigh says.

Oppenheimer envisioned experiments for radioactive decay, the Doppler effect and Millikan oil drops, among many other elements of physics, and received national acclaim for the Library of Experiments while he was at CU.

"His 'library' of sophisticated science toys operated in typical Frank style—which is to say with a large measure of anarchy," Cole wrote. "He insisted on not having a lab manual, for instance, because he thought it would be too confining and inhibit free exploration. He liked to work with students one on one, encouraging them to ask questions and always making suggestions: 'Why don't you try this?'"

Having a lab with Oppenheimer was an incomparable educational experience, even for a professional, Bartlett told Cole. "He was personally setting an example of how fascinating it was to be engrossed in the excitement of learning physics. His enthusiasm was contagious. He seemed to take so much pleasure getting other people to see the interesting things in what he was doing."

In retrospect, it’s easy to see that Oppenheimer was testing ideas for what would become the Exploratorium, a hands-on public learning laboratory for all ages in San Francisco, California. Prior to founding it in 1969, Oppenheimer was awarded the first of two Guggenheim Fellowships in 1965 to study the history of physics and research bubble chambers at University College London. (The University of Colorado granted Oppenheimer a series of leaves until he became professor emeritus in 1979.)

Left photo: Frank Oppenheimer (right) with his older brother, J. Robert Oppenheimer. Right photo: Frank Oppenheimer in his later years in San Francisco; he died in 1985. (Left photo: AIP Emilio Segrè Visual Archives; right photo: K.C. Cole/courtesy Houghton Mifflin)

A legacy of learning

Oppenheimer built the Exploratorium into a nationally and internationally recognized center for public science, never losing his curiosity or enthusiasm for science, Franklin says. He recalls visiting Oppenheimer and his wife in San Francisco around 1970.

“They had a house near the top of Lombard Street, and when I was staying with them I remember seeing an ad in the paper that Jefferson Airplane were going to be playing at the Fillmore West,” Franklin says. “I asked Frank if he wanted to go and he said yes, which shouldn’t have been surprising because he was always curious and open to new things. We were older than the rest of the audience, and people were looking at us like we were narcs. But they played a 30-minute version of ‘White Rabbit’ at that show, and I remember Frank was really into it.”

Despite Oppenheimer’s relatively short time at CU, his legacy is woven into the fabric of the Department of Physics. “Teaching and learning have been central for this department forever," Beale says. "Like when Frank was here, we have students doing hands-on, real science—publishable stuff when they’re even freshmen and sophomores. One example from the COVID era was something students could work on online, using this huge dataset available from NASA that had not been combed through at a level it needed to be. So, students were doing that real-world data analysis and then having a published paper in an astrophysical journal about solar flares at the end of it.

“I tell students when I first meet them coming out of high school that science is a human endeavor; there has to be room for trial and error. If you do an experiment and get what you expect every time, you haven’t really learned anything or done science. I think that’s why we wanted Frank here in the first place, because he strongly believed that, too.”

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In a little-known chapter of university history, the Manhattan Project scientist taught for several years in the Department of Physics, and his legacy appears in the fabric of the department.

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Paul Phillipson, physics department's first biophysicist, dies at 90

Anonymous — Thu, 30 Nov 2023 18:30:26 +0000

Paul Phillipson, physics department's first biophysicist, dies at 90 Anonymous (not verified) Thu, 11/30/2023 - 11:30

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Pursuing purpose through physics

Anonymous — Fri, 03 Nov 2023 17:07:04 +0000

Pursuing purpose through physics Anonymous (not verified) Fri, 11/03/2023 - 11:07

Rachel Sauer

Gary Wall, a 1970 CU Boulder physics graduate, won the Los Alamos Medal in recognition of more than 50 years of distinguished work at Los Alamos National Laboratory

During the summer of 1970, his first year working at the Los Alamos National Laboratory in New Mexico, Gary Wall was something of a hippie and wore a large peace sign pendant to work most days. He still has it, and there’s nothing subtle about it.

“I initially had reservations about working there,” Wall recalls of his graduate research assistant position at the physical and scientific home of the Manhattan Project. “I applied because my girlfriend at the time was from Los Alamos.”

However, it wasn’t very long before “I became convinced the nuclear deterrent is what is keeping us out of world wars,” he says. “The purpose of a nuclear deterrent is to keep the peace. I did struggle that first summer when I found out that I was going to be working in the nuclear weapons group—I struggled with whether that’s really what I wanted to do—but every day I learned more about how we’re supporting the work of protecting the country and protecting the world from a third world war, hopefully.”

Gary Wall accepts the Los Alamos Medal from Laboratory Director Thom Mason at a special awards ceremony. (Photo: Los Alamos National Laboratory)

Since that summer of 1970, a month after he graduated the �鶹��Ƶ with a bachelor’s degree in physics, Wall has become one of the most distinguished designers in the Los Alamos National Laboratory (LANL) Weapons Physics group. In recognition of his more than 50 years of work, he won the Los Alamos Medal, the laboratory’s highest honor.

The Los Alamos Medal recognizes recipients who have made contributions that changed the course of science, made major enhancement to the laboratory’s ability to achieve its mission or established a major direction for the laboratory and the nation.

“All the fields in physics are challenging, and they’re stimulating,” Wall says. “National labs are great places to work, and physics is a great field. There are always new frontiers to investigate in physics, and even 50 years later, I’m still making discoveries in physics.”

A love for science

Growing up in Englewood, Colorado, Wall was always drawn to science—charting his own path in a family in which his father did construction and remodeling work and his mother was a homemaker. He joined his father on jobs during summer months and dove back into the solution-finding and figuring-things-out of science when he resumed classes at Englewood High School.

He won a Boettcher Scholarship—“the only way I could attend college, because we couldn’t have afforded it otherwise,” Wall says—and began classes at CU Boulder in 1965, studying physics and math. The math was to help him keep up with the physics, he says.

His junior year abroad in England explains why he graduated in 1970 instead of 1969, he says, “but it was a fun year out. It was really interesting to study American history from a British perspective and to study British literature in the country where it was written.”

After graduating, and encouraged by his girlfriend, Wall applied for and received a graduate research-assistant position at LANL. He thought it would just be for the summer, since an advisor at CU recommended he pursue graduate studies at a different university than where he completed his undergraduate work. So, in the fall of 1970, he headed to the University of Minnesota.

“I didn’t like the big city, and I definitely didn’t like six months of winter,” he says, so the following summer he headed back to Los Alamos, and that’s where he stayed. He earned his master’s degree in mathematics from the University of New Mexico in 1976.

Gary Wall running near his Los Alamos, New Mexico, home.

Balancing physics and engineering

In his undergraduate studies at CU, Wall had been fascinated with nuclear physics. As he learned in his second summer at LANL, and through the span of his five decades of work there, all areas of physics are involved in designing nuclear weapons—not just nuclear physics.

It’s a little difficult to describe what his work has entailed because the bulk of it is classified (Wall has a Q security clearance, the equivalent of top secret), “but the idea is that there is a requirement from the Department of Defense for some new weapon to go on some new delivery system and they set requirements for what they want,” Wall explains. “We take those requirements and put together ideas for what kind of device will meet them.

“Then, there’s a lot of physics design and engineering design to put together a device. Then, there’s a lot of testing of the function of the device, and at least until 1992 (when LANL conducted its last underground test at the Nevada Test Site), we’d go out to Nevada and do underground tests to verify that what we designed will work.”

On his first test at the Nevada Test Site, Wall was a junior member of the design team and had been tasked with writing a pre-shot report for a particular nuclear test his team had been working on. When it came time to do the test in Nevada, “I was on the spot having to say how well it was going to work,” he says. “As a junior member of the team, that was a lot of responsibility.”

Over the years, there were designs that didn’t work the way they were supposed to, but failures are also part of scientific learning, Wall says. As computer technology advanced, the LANL nuclear design group grew its capacities—using computer design calculations to look at variations and uncertainties. Plus, every design went through a battery of internal peer review and sometimes even inter-lab peer review with other national laboratories.

“The internal peer review was pretty intense, so that by the time we got to fielding tests in Nevada, we were reasonably confident that the design was sound,” Wall says.

“In this work, there’s physics and there’s engineering. We can design things in the computer, but then engineers have to figure out how to build it. It’s a give and take between the computer design and what can actually be built.

Gary Wall stands near the location of Divider, the last nuclear test before the current moratorium. (Photo: Los Alamos National Laboratory)

“The piece we do is called physics design, and we use all the different areas of physics that feed into the function of a nuclear weapon—codes, high explosives, hydrodynamics, material properties. Then, the design that gets finalized also has to meet requirements for being transported and actually being put on a delivery system, it has to meet environmental requirements. So, those are requirements we have to meet as well.”

Still learning

Though Wall technically retired in 2018, he still works half-time when he and his wife aren’t traveling. In 2005, he was named a laboratory fellow in recognition of special achievement, so now his title is lab associate fellow. One of the things he relishes most in his position now is mentoring the next generation of scientists.

“Gary’s commitment to mentoring the next generation of nuclear weapons scientists is just as—if not more—impressive than his long list of accomplishments,” Bob Webster, deputy laboratory director for weapons at LANL, said in a statement about the award.

“Los Alamos Laboratory has been a wonderful place to learn to be a scientist,” Wall says. “The lab does a lot beyond weapons, so there’s lots of opportunity to focus on various aspects of physics and fielding experiments that focus on different parts of physics. It’s a place where I’m still learning.”

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Gary Wall, a 1970 CU Boulder physics graduate, won the Los Alamos Medal in recognition of more than 50 years of distinguished work at Los Alamos National Laboratory.

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New technique uses near-miss particle physics to peer into quantum world − two physicists explain how they are measuring wobbling tau particles

Anonymous — Tue, 17 Oct 2023 21:43:29 +0000

New technique uses near-miss particle physics to peer into quantum world − two physicists explain how they are measuring wobbling tau particles Anonymous (not verified) Tue, 10/17/2023 - 15:43

Jesse Liu , Dennis V. Perepelitsa

One way physicists seek clues to unravel the mysteries of the universe is by smashing matter together and inspecting the debris. But these types of destructive experiments, while incredibly informative, have limits.

We are two scientists who study nuclear and particle physics using CERN’s Large Hadron Collider near Geneva, Switzerland. Working with an international group of nuclear and particle physicists, our team realized that hidden in the data from previous studies was a remarkable and innovative experiment.

In a new paper published in Physical Review Letters, we developed a new method with our colleagues for measuring how fast a particle called the tau wobbles.

Our novel approach looks at the times incoming particles in the accelerator whiz by each other rather than the times they smash together in head-on collisions. Surprisingly, this approach enables far more accurate measurements of the tau particle’s wobble than previous techniques. This is the first time in nearly 20 years scientists have measured this wobble, known as the tau magnetic moment, and it may help illuminate tantalizing cracks emerging in the known laws of physics.

Top of the page:The Large Hadron Collider at CERN can be used to study many kinds of fundamental particles, including mysterious and rare tau particles. Above: Electrons, muons and taus all wobble in a magnetic field like a spinning top. Measuring the wobbling speed can provide clues into quantum physics. Jesse Liu, CC BY-ND

Why measure a wobble?

Electrons, the building blocks of atoms, have two heavier cousins called the muon and the tau. Taus are the heaviest in this family of three and the most mysterious, as they exist only for minuscule amounts of time.

Interestingly, when you place an electron, muon or tau inside a magnetic field, these particles wobble in a manner similar to how a spinning top wobbles on a table. This wobble is called a particle’s magnetic moment. It is possible to predict how fast these particles should wobble using the Standard Model of particle physics – scientists’ best theory of how particles interact.

Since the 1940s, physicists have been interested in measuring magnetic moments to reveal intriguing effects in the quantum world. According to quantum physics, clouds of particles and antiparticles are constantly popping in and out of existence. These fleeting fluctuations slightly alter how fast electrons, muons and taus wobble inside a magnetic field. By measuring this wobble very precisely, physicists can peer into this cloud to uncover possible hints of undiscovered particles.

Electrons, muons and taus are three closely related particles in the Standard Model of particle physics – scientists’ current best description of the fundamental laws of nature. MissMJ, Cush/Wikimedia Commons

Testing electrons, muons and taus

In 1948, theoretical physicist Julian Schwinger first calculated how the quantum cloud alters the electron’s magnetic moment. Since then, experimental physicists have measured the speed of the electron’s wobble to an extraordinary 13 decimal places.

The heavier the particle, the more its wobble will change because of undiscovered new particles lurking in its quantum cloud. Since electrons are so light, this limits their sensitivity to new particles.

Muons and taus are much heavier but also far shorter-lived than electrons. While muons exist only for mere microseconds, scientists at Fermilab near Chicago measured the muon’s magnetic moment to 10 decimal places in 2021. They found that muons wobbled noticeably faster than Standard Model predictions, suggesting unknown particles may be appearing in the muon’s quantum cloud.

Taus are the heaviest particle of the family – 17 times more massive than a muon and 3,500 times heavier than an electron. This makes them much more sensitive to potentially undiscovered particles in the quantum clouds. But taus are also the hardest to see, since they live for just a millionth of the time a muon exists.

To date, the best measurement of the tau’s magnetic moment was made in 2004 using a now-retired electron collider at CERN. Though an incredible scientific feat, after multiple years of collecting data that experiment could measure the speed of the tau’s wobble to only two decimal places. Unfortunately, to test the Standard Model, physicists would need a measurement 10 times as precise.

Instead of colliding two nuclei head-on to create tau particles, two lead ions can whiz past each other in a near miss and still produce taus. Jesse Liu, CC BY-ND

Lead ions for near-miss physics

Since the 2004 measurement of the tau’s magenetic moment, physicists have been seeking new ways to measure the tau wobble.

The Large Hadron Collider usually smashes the nuclei of two atoms together – that is why it is called a collider. These head-on collisions create a fireworks display of debris that can include taus, but the noisy conditions preclude careful measurements of the tau’s magnetic moment.

From 2015 to 2018, there was an experiment at CERN that was designed primarily to allow nuclear physicists to study exotic hot matter created in head-on collisions. The particles used in this experiment were lead nuclei that had been stripped of their electrons – called lead ions. Lead ions are electrically charged and produce strong electromagnetic fields.

The electromagnetic fields of lead ions contain particles of light called photons. When two lead ions collide, their photons can also collide and convert all their energy into a single pair of particles. It was these photon collisions that scientists used to measure muons.

These lead ion experiments ended in 2018, but it wasn’t until 2019 that one of us, Jesse Liu, teamed up with particle physicist Lydia Beresford in Oxford, England, and realized the data from the same lead ion experiments could potentially be used to do something new: measure the tau’s magnetic moment.

This discovery was a total surprise. It goes like this: Lead ions are so small that they often miss each other in collision experiments. But occasionally, the ions pass very close to each other without touching. When this happens, their accompanying photons can still smash together while the ions continue flying on their merry way.

These photon collisions can create a variety of particles – like the muons in the previous experiment, and also taus. But without the chaotic fireworks produced by head-on collisions, these near-miss events are far quieter and ideal for measuring traits of the elusive tau.

Much to our excitement, when the team looked back at data from 2018, indeed these lead ion near misses were creating tau particles. There was a new experiment hidden in plain sight!

The Large Hadron Collider accelerates particles to incredibly high speeds before trying to smash particles together, but not all attempts result in successful collisions. Maximilien Brice/CERN, CC BY-SA

First measurement of tau wobble in two decades

In April 2022, the CERN team announced that we had found direct evidence of tau particles created during lead ion near misses. Using that data, the team was also able to measure the tau magnetic moment – the first time such a measurement had been done since 2004. The final results were published on Oct. 12, 2023.

This landmark result measured the tau wobble to two decimal places. Much to our astonishment, this method tied the previous best measurement using only one month of data recorded in 2018.

After no experimental progress for nearly 20 years, this result opens an entirely new and important path toward the tenfold improvement in precision needed to test Standard Model predictions. Excitingly, more data is on the horizon.

The Large Hadron Collider just restarted lead ion data collection on Sept. 28, 2023, after routine maintenance and upgrades. Our team plans to quadruple the sample size of lead ion near-miss data by 2025. This increase in data will double the accuracy of the measurement of the tau magnetic moment, and improvements to analysis methods may go even further.

Tau particles are one of physicists’ best windows to the enigmatic quantum world, and we are excited for surprises that upcoming results may reveal about the fundamental nature of the universe.

Jesse Liu, Research Fellow in Physics, University of Cambridge and Dennis V. Perepelitsa, Associate Professor of Physics, �鶹��Ƶ

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Science-education experts recognized for ground-breaking work

Anonymous — Fri, 13 Oct 2023 16:22:07 +0000

Science-education experts recognized for ground-breaking work Anonymous (not verified) Fri, 10/13/2023 - 10:22

CU Boulder professors Noah Finkelstein of physics and Valerie Otero of education have won the 2023 Svend Pedersen Award and Lecture from Stockholm University

Two experts in science education at the �鶹��Ƶ have won the Svend Pedersen Award and Lecture of 2023 for their “major and lasting” contribution to science education, Stockholm University has announced.

Noah Finkelstein, professor of physics, and Valerie Otero, professor of science education, share the 2023 award and are planning to deliver a joint lecture in Sweden early next year.

Stockholm University bestows the Svend Pedersen Award and Lecture annually to a researcher who has made a “major and lasting contribution” within the fields of mathematics education or science education internationally.

The award, which was unsolicited, recognizes their joint contribution to “teacher education praxis.” The cross-disciplinary collaboration between physics and education “led to the development of the highly influential and successful Learning Assistant Program,” Stockholm University said.

Noah Finkelstein and Valerie Otero

“Finkelstein and Otero are both leading researchers in physics/science education, and both their individual and collaborative work has gained recognition internationally and inspired researchers at the Department of Teaching and Learning at Stockholm University,” the award citation notes.

Finkelstein’s research focuses on university students’ interests and capacities in physics and also on educational transformations. Finkelstein is one of leads of the Physics Education Research (PER) group and was founding co-director, with Otero, of CU’s Center for STEM Learning.

Otero’s research focuses on the interplay of learning environments, instructional teams and materials that make learning more accessible. Otero is the faculty director and co-founder of CU Boulder’s Learning Assistant Program and the International Learning Assistant Alliance.

Finkelstein’s research projects range from the specifics of students’ learning particular concepts to the departmental and institutional scales of sustainable educational transformation. His research has yielded more than 150 publications.

He is increasingly involved in education policy and in 2010 testified before the U.S. Congress on the state of STEM education at the undergraduate and graduate levels. He serves on many national boards, including chairing both the American Physical Society’s Committee on Education and PER Topical Group.

He is a Fellow of both the American Physical Society and the American Association for the Advancement of Science, and a Presidential Teaching Scholar and the inaugural Timmerhaus Teaching Ambassador for the University of Colorado system.

Explaining his research focus, Finkelstein says, “At root, I see higher education as a fundamental public good—advancing the lives of individuals and capacities of our societies more broadly. In the long haul, I know of no better way to enhance societies and individuals' lives than to support the core missions of our colleges and universities, and to help them realize the promises that they hold toward these ends.”

He acknowledges that there is much work still to do. “And that's where I spend my time—through teaching and educational programs, through my research and scholarly work, and through my professional service efforts. I particularly focus on higher education—colleges and universities—as these are a tremendous resource and lever for change in our broader educational system.”

Partly in response to expert warnings that the nation was falling behind its international peers in science education, U.S. educators have in the past two decades renewed their focus on science, technology, engineering and mathematics (or STEM) education. This focus is reflected in levels of funding, national discourse, programs focused in STEM, numbers of students, diversity of students and even faculty hiring trends, Finkelstein says.

I see higher education as a fundamental public good—advancing the lives of individuals and capacities of our societies more broadly. In the long haul, I know of no better way to enhance societies and individuals' lives than to support the core missions of our colleges and universities, and to help them realize the promises that they hold toward these ends.”

“Two decades ago, it was far less common to find discipline-based education researchers—folks such as myself hired into disciplinary departments to conduct research on education from within,” he observes, adding that when he was hired in 2003, CU Boulder was “extremely forward-looking” in such a hire.

“Now it is both much more common and CU has established itself as an international leader in this space, boasting researchers across a wide array of disciplinary departments focusing on education and in schools of education focusing on undergraduate science learning,” he says.

Finkelstein also notes that educators have broadened goals in their courses “to focus on the whole array of learning and educational practice, rather than the initial staples of attending to students’ conceptual understanding and algorithmic capacities.”

Now, he adds, “we are attending to how students think about our fields; what habits of mind they are developing; how we build inclusive environments and support a sense of belonging among the breadth of learners; who we are not including and why.”

Additionally, educators have also moved way from viewing their jobs as “fixing students” or addressing their "deficiencies" and now place greater emphases on the “systems that our learners are participating in to support their substantial capacities.”

Otero is internationally recognized for her foundational work with the Learning Assistant (LA) model and the International LA Alliance. The LA model was established in 2001 when Otero was hired by the �鶹��Ƶ in STEM education and as the first physics education researcher at CU Boulder.

She is a President’s Teaching Scholar and served as an advisor for NASA, on committees for the National Academy of Science and is a fellow of the American Physical Society, which awarded her team the Excellence in Physics Education Award in 2019 for their work on the LA model.

The LA model improves student success by increasing the diversity of CU Boulder’s instructional teams through the inclusion of pedagogically trained undergraduate LAs. Otero’s team provides continuing development opportunities for professors and undergraduates, supporting their growth as educational leaders, mentors and state-of-the-art educational innovators.

“Working with LAs has helped me refresh my teaching strategies and resist the temptation to just do what's worked in the past,” a participating professor commented. “I enjoy helping LAs take on responsibility and gain confidence in their leadership skills, and in turn, this experience reminds me of the greater purpose and goals of education.”

LAs rarely provide direct instruction; instead, they facilitate group interactions, answer questions that students may be embarrassed to ask instructors and give general guidance such as how to study and where to find health care resources.

They relate to students, give them voice, care about them and help them learn. LAs plan and reflect with professors, providing information about how students are experiencing the course, bringing students closer to the professor, especially in large courses.

Learning Assistants maintain both a peer and educator role, which may allow the breaking down of psychological barriers in the minds of students due to formal boundaries, possibly preventing them from seeking help for fear of bothering the professor or appearing incompetent.”

participating LA observed, “LAs maintain both a peer and educator role, which may allow the breaking down of psychological barriers in the minds of students due to formal boundaries, possibly preventing them from seeking help for fear of bothering the professor or appearing incompetent.”

Today, approximately 400 LAs are hired each year at CU Boulder, serving more than 20,000 students each year. Research shows that students who have experienced a STEM course with LAs are 60% more likely to succeed in subsequent STEM courses. The model has caught on.

Universities all over the world have realized that the LA model can transform their institutions, building lasting capacity for sustained offerings of high-quality, learner-centered instruction.

In these settings, students feel included and valued and are comfortable accessing multiple forms of support in and outside of the classroom. The thousands of CU Boulder students who have served as LAs and LA mentors have become effective leaders, teachers and team members, prepared for the increasingly diverse and interdisciplinary workforce.

On Oct. 27, professors from universities around the world will come to CU Boulder, as they do each year, to learn about and share research regarding the LA model.

Otero founded the Learning Assistant Alliance in 2009, and since then, more than 3,000 professors from more than 560 universities and 28 countries have joined. Otero has been invited to Norway, Egypt, Japan and the United Kingdom to provide guidance and support for country-level adoptions of the LA Model.

Otero is also known for her foundational work with PEER Physics, a high school physics curriculum and teacher professional learning community adopted by high schools from Seattle to New York.

“We used to be gullible before this class, but now evidence has our backs,” a PEER Physics student said, while another noted, “This course has provided a very safe and helpful learning environment for me. This class is all about working with others and has really helped me learn the material—it has also lifted my spirits about the science subject in general.”

A PEER Physics teacher said, “PEER Physics gives ownership to students who haven’t had ownership in other science classrooms before. It empowers them to take charge of their own learning rather than just being fed information. I think it challenges their analytical skills.”

Another teacher said, “I think if the PEER Physics teacher community didn’t exist, I would have left education. This has kept me in, really enhanced my life, and the life of my students.”

Otero found empowerment and joy in physics when she took her first physics course at the University of New Mexico. “I always loved learning,” she says. “My dad always taught us that learning is a great privilege, and I committed my life to making positive learning opportunities available for students like me.”

As a first-generation college student, Otero has first-hand knowledge about how a Hispanic woman can navigate physics and academia and achieve great success through a supportive community like CU Boulder. Otero says that she developed leadership skills by working at her parents’ grocery store and at the New Mexico State Fair since she was 12.

Twenty-three years after starting at CU Boulder, she continues to work with the Learning Assistant Alliance and PEER Physics to find ways to include, rather than exclude, people from physics.

Did you enjoy this article? Subcribe to our newsletter. Want to learn more? View Otero's Ed Talk at this link.

CU Boulder professors Noah Finkelstein of physics and Valerie Otero of education have won the 2023 Svend Pedersen Award and Lecture from Stockholm University.

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Three CU Boulder profs win Boettcher Foundation awards

Anonymous — Mon, 12 Jun 2023 23:12:26 +0000

Three CU Boulder profs win Boettcher Foundation awards Anonymous (not verified) Mon, 06/12/2023 - 17:12

The awards are part of $1.88 million in 2023 biomedical research grant funding for Colorado researchers

Three �鶹��Ƶ assistant professors have been named 2023 Boettcher Investigators, each earning $235,000 in grant funding to support up to three years of biomedical research. The 13-year-old program invests in leading Colorado researchers during the early stages of their careers, providing support to fund their independent scientific research.

Nuris Figueroa Morales studies the complex interactions between microorganisms and their environment.

The three CU Boulder award winners and their fields of study are:

Nuris Figueroa, assistant professor, physics; studying the mechanics of mucus organization and transport;
Halil Aydin, assistant professor, biochemistry; investigating cellular and molecular mechanisms of mitochondrial form and function in human health and disease; and
Nick Bottenus, assistant professor, biomedical, mechanics of materials, and robotics and systems design in the College of Engineering and Applied Science; studying binding kinetics of targeted microbubble agents.

Funding for the awards is made possible in part by the Webb-Waring Biomedical Research Awards program, which is administered by the Boettcher Foundation.

“It’s an honor to be acknowledged by a distinguished organization,” Aydin said of the Boettcher Foundation. “The Boettcher Foundation Webb-Waring Biomedical Research Award will grant our laboratory the opportunity to develop novel approaches and push the boundaries of high-resolution imaging and structural cell biology to advance our understanding of how cellular machines function normally, and how they are corrupted by disease. An integrative understanding of how protein machines function has implications for targeting cardiovascular diseases, metabolic disorders, cancers, aging and a wide range of neurodegenerative diseases.”

Halil Aydin is an expert in membrane biology, cell signaling, proteins and enzymology, molecular biophysics, structural biology, and electron cryo-microscopy (cryoEM).

Figueroa also expressed thanks to the Boettcher Webb-Waring Biomedical Research Program and for what the funding will mean for her research team’s work.

“With this research grant, my team and I will have the means to investigate mechanical properties of lung mucus, how it flows, and how bacteria navigate in it,” she said. “Our research will look at the biophysics of lung-obstructive diseases using new quantitative and interdisciplinary tools, to further understand causes and consequences of failed mucus clearance and hopefully device solutions.”

Bottenus said, “Being named a Boettcher Investigator is an amazing career milestone. I’m grateful to become a part of a rich community of biomedical researchers throughout Colorado. This award will allow my group to grow in new directions, applying our acoustics and signal processing techniques to more fundamental biological investigations. I hope that our work will translate to improved diagnostic imaging, personalized medicine, and accessible health care technologies as we pursue new approaches to molecular imaging.”

Assistant Professor Nick Bottenus' research is focused on developing system-level solutions to problems in diagnostic ultrasound imaging.

The awards given to the three CU Boulder assistant professors are part of a larger pot of $1.88 million grant funding awarded to eight individuals from four of Colorado’s research institutions: CU Boulder, University of Colorado Anschutz Medical Campus,Colorado State University and National Jewish Health.

“We are thrilled to support our 2023 Boettcher Investigators, and as proud investors in their work, we are confident that these exceptional researchers will continue to push the boundaries of discovery and medical breakthrough,” said Katie Kramer, president and CEO of the Boettcher Foundation. “Their innovative research holds the promise of transformational impact that will drive progress in health care and make a meaningful difference in the lives of Coloradans.”

Since its inception in 2010, the Webb-Waring Biomedical Research Awards program has advanced the work of 98 Boettcher Investigators with more than $20 million in grant funds. The researchers have attracted more than $150 million in additional independent research funding from federal, state and private sources.

“Colorado BioScience Association applauds Boettcher Foundation’s support of Colorado’s most dynamic and promising researchers,” said Elyse Blazevich, president and CEO of the Colorado BioScience Association.

“The Webb-Waring Biomedical Awards program invests in Colorado researchers at a pivotal time in their careers and encourages them to deepen their roots in Colorado as they contribute to the leading-edge health innovations coming from our state.”

The awards are part of $1.88 million in 2023 biomedical research grant funding for Colorado researchers.

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Mapping the Milky Way in a can of olive oil

Anonymous — Tue, 16 May 2023 16:20:25 +0000

Mapping the Milky Way in a can of olive oil Anonymous (not verified) Tue, 05/16/2023 - 10:20

Daniel Long

Assistant Professor Meredith MacGregor and NIST Physicist Jake Connors taught their graduate students how to build and use radio horn antennas to locate neutral hydrogen in space

Meredith MacGregor, CU Boulder assistant professor of astrophysics, and Jake Connors, a physicist at the National Institute of Standards and Technology (NIST), wanted to teach their graduate students in Astrophysics 6000 (ASTR 6000) the basics of radio astronomy. But how?

“Jake and I had been trying to brainstorm how we would teach radio astronomy in a way that would get students excited and actually learn it,” says MacGregor.

Then they had an idea—a brainwave, as it were: Why not teach their students how to build and then use pyramidal horn antennas as do-it-yourself radio telescopes?

Top of page: MacGregor and Connors’s students pointing their radio antennas to the sky outside Duane Physics. Above: One of MacGregor and Connors’s students dunking a piece of foam into liquid nitrogen. The foam and the nitrogen were used to help calibrate the radio antennas. Photo courtesy of MacGregor and Connors.

“It just seemed better to do something creative instead of sitting in a classroom and lecturing people,” says MacGregor.

Connors agrees. A hands-on approach, he says, “is a way to reach those students who aren’t keen on learning from people writing on the board.”

So, they and their students got to work.

The method

State-of-the-art radio antennas, like the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, can cost billions of dollars to construct, but perfectly serviceable ones can be built for less than $100. All it takes is a bit of ingenuity.

For the horn, which acts as a funnel for the radio signal, MacGregor and Connors’s students used metallized home insulation. “We literally drove to Home Depot, bought pieces of insulation, strapped them to the roof of a car and drove them to campus,” recalls MacGregor.

And for the waveguide, which picks up the signal at the narrow end of the horn, they used cans of olive oil from Whole Foods. “The olive oil cans turned out to be exactly the right size, conveniently enough,” says MacGregor. “Whole Foods makes really great olive oil cans.”

(They emptied the oil from the cans but wasted none of it. “My pantry is full of olive oil right now,” says MacGregor.)

They also purchased a software-defined radio, or SDR, from Amazon, which Connors says functioned a bit like a microphone, amplifying, sampling and digitizing the astronomical signals before sending them to a computer.

All in all, the students of ASTR 6000 built three antennas. And when they pointed them skyward, they searched for one thing in particular: neutral hydrogen in the arms of the Milky Way.

The element

Hydrogen has one proton and one electron, each of which has a property called spin, MacGregor explains. These spins can be in alignment, with both going up or down, or they can be opposed.

But when the spin of the electron flips, it gives off a 21-centimeter radio wavelength, otherwise known as the hydrogen line, the finding of which provides a kind of window view upon the galaxy.

MacGregor (center, in blue) speaking with her students. The radio antenna is in the foreground. Photo courtesy of MacGregor and Connors.

“Our galaxy has this spiral-arm structure,” says MacGregor, “and in those arms are a bunch of gas clouds that are mostly made up of hydrogen.”

Connors adds that these gas clouds are moving relative to the earth because of the way the galaxy rotates.

“They’re orbiting the same supermassive black hole at the center of the galaxy that we are. But because they’re moving at a different distance from the center of the galaxy than we are, they’re moving at a different velocity potentially.”

These different velocities then create different Doppler shifts, which the horn antennas detect.

“Much like if you stand on a sidewalk and hear an ambulance go by, when it’s coming toward you, the ambulance siren sounds really high pitched, and then, as it goes past you, the pitch drops,” says Connors.

“It’s that same Doppler shift, except for light. We’re actually observing the light emitted from those hydrogen clouds.”

Different gas clouds produce different Doppler shifts, and those different Doppler shifts represent different velocities.

“And then you can say, ‘I looked in this line of sight, and I saw these different arms of the galaxy.’ And then you look at another line of sight, and you’ll see some different distribution of velocities. And so you can basically map the entire galaxy,” says MacGregor.

The bigger picture

Student Jay Chittidi says building the radio antennas “was one of the most engaging hands-on labs that I have had as a grad student. This approach really solidified our understanding of the basics of radio astronomy, because we had to plan with them in mind when building and observing with our antennas.”

Left: One of the radio antennas from ASTR 6000 (photo courtesy of MacGregor and Connors). Right: The horn antenna used by Edward Purcell and Harold Ewen in the early '50s, pictured with Ewen.

But MacGregor and Connors say they believe the lessons gleaned from this exercise go beyond hydrogen gas clouds and radio antennas specifically.

“I’m hoping to ignite a passion in the students for doing instrumentation,” says Connors. “There is a dearth of people who are out there building the instruments to enable observations to take place. Seeing both sides of how astrophysics works is really valuable for students’ careers and understanding.”

“We’d really like students to have an understanding of how we do observational science on all levels,” says MacGregor.

She points out that the initial measurement of the 21-centimeter line and subsequent mapping of the galaxy were major breakthroughs in physics, and yet the scientists responsible for those breakthroughs, Harold Ewen and Edward Purcell, used a horn antenna very much like the ones built in ASTR 6000.

“And I think that’s a very powerful lesson.”

Assistant Professor Meredith MacGregor and NIST Physicist Jake Connors taught their graduate students how to build and use radio horn antennas to locate neutral hydrogen in space.

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