News

Postings created for publication in the Physics Department web page news feed.

The passing of Dr. David Katzenstein, a friend and benefactor of the UConn Department of Physics

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Dr. David Katzenstein, a friend, and benefactor of the UConn Department of Physics, passed away on January 25, 2021 due to Covid-19. David was the son of Henry Katzenstein, the first Physics Ph.D. from UConn and a major benefactor of our Department. Currently, both the annual Katzenstein Distinguished Lecture and the Katzenstein Prize for a senior, undergraduate paper were endowed by the Katzenstein family.

David himself was an Emeritus Professor of Medicine at the Stanford University Medical School, specializing in Infectious Diseases and Geographic Medicine. He focused on the treatment and prevention of HIV-AIDS, particularly in sub-Saharan Africa. He died in Harare, Zimbabwe where he had moved in 2016 to continue his important work after his retirement from Stanford.

Obituary in NYTimes: David Katzenstein, AIDS Researcher With Focus on Africa, Dies at 69

A Signal from Beyond

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Looking for ripples in the fabric of spacetime.

UConn astrophysicist Chiara Mingarelli is part of a team of researchers who recently published data on a hint of a signal that sent ripples of excitement through the physics community. These monumental findings are the culmination of twelve and a half years of data gathered from NANOGrav — a network of pulsars across the galaxy — all in the hopes of detecting gravitational waves.

Gravitational waves are generated when galaxies merge and supermassive black holes at their centers collide and send low-frequency gravitational waves out into the universe. The team thinks the source of the signal could be gravitational waves, but it will take about 2 more years of data to be sure.

The findings sparked the interest of other physicists with their own speculations about the signal, such as cosmic strings or primordial black holes. Though still a couple of years away, Mingarelli says the final results could also help test General Relativity or even open the door to entirely new physics.

This article first appeared on UConn Today, February 15, 2021

UConn Physics alumnus Dr. Michael Wininger

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UConn Physics alumnus Dr. Michael Wininger (BS, 2003) was recently featured in the professional journal O&P Almanac (Orthotics and Prosthetics). The article describes how his eclectic background, beginning with degrees from UConn, has enabled him to lead innovations in several areas of health research. Mike is currently an Assistant Clinical Professor in the Biostatistics Department at the Yale School of Public Health while also holding a co-appointment with the Department of Veterans Affairs Cooperative Studies Program. Michael says that former Professor Ed Pollack was particularly instrumental in mentoring towards a successful career, and in gratitude has been a frequent contributor to the Edward Pollack Endowment Fund, which supports our annual Pollack Lecture in Atomic Physics. Some of the old-timers around the department remember Mike for his always energetic presence around the department and help with our bicycles.

UConn Researcher an Architect for Astronomical Survey Making Observations Toward a New Understanding of the Cosmos

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November 2, 2020 – Elaina Hancock – UConn Communications

The Sloan Digital Sky Survey’s fifth generation – a groundbreaking project to bolster our understanding of the formation and evolution of galaxies, including the Milky Way – collected its very first observations on the evening of October 23.

Image: The Sloan Digital Sky Survey’s fifth generation made its first observations earlier this month. This image shows a sampling of data from those first SDSS-V data. The central sky image is a single field of SDSS-V observations. The purple circle indicates the telescope’s field-of-view on the sky, with the full Moon shown as a size comparison. SDSS-V simultaneously observes 500 targets at a time within a circle of this size. The left panel shows the optical-light spectrum of a quasar–a supermassive black hole at the center of a distant galaxy, which is surrounded by a disk of hot, glowing gas. The purple blob is an SDSS image of the light from this disk, which in this dataset spans about 1 arcsecond on the sky, or the width of a human hair as seen from about 21 meters (63 feet) away. The right panel shows the image and spectrum of a white dwarf — the left-behind core of a low-mass star (like the Sun) after the end of its life.Image Credit: Hector Ibarra Medel, Jon Trump, Yue Shen, Gail Zasowski, and the SDSS-V Collaboration. Central background image: unWISE / NASA/JPL-Caltech / D.Lang (Perimeter Institute).

“In a year when humanity has been challenged across the globe, I am so proud of the worldwide SDSS team for demonstrating — every day — the very best of human creativity, ingenuity, improvisation, and resilience. It has been a wild ride, but I’m happy to say that the pandemic may have slowed us, but it has not stopped us,” says Juna Kollmeier, director of the project known as SDSS-V.

The project is funded primarily by an international consortium of member institutions, along with grants from the Alfred P. Sloan Foundation, U.S. National Science Foundation, and the Heising-Simons Foundation.

Jonathan Trump, UConn assistant professor of physics, has a long history with SDSS, and is one of the architects for the fifth installment of the program. He is also serving as the cadence coordinator for the project’s black hole science goals.

“My very first undergrad research project was an SDSS project. I have worked on SDSS as a post-doc, and I am working on it now as faculty,” Trump says. “I’ve been part of it from the first SDSS iteration, and as it has taken off, so has my career.”

Trump and his colleagues will focus on three primary areas of investigation with SDSS-V, each exploring different aspects of the cosmos using different spectroscopic tools. Together, these three project pillars—called “Mappers”—will observe more than six million objects in the sky, and monitor changes in more than a million of those objects over time.

The survey’s Local Volume Mapper will enhance our understanding of galaxy formation and evolution by probing the interactions between the stars that make up galaxies and the interstellar gas and dust that is dispersed between them. The Milky Way Mapper will reveal the physics of stars in our Milky Way, the diverse architectures of its star and planetary systems, and the chemical enrichment of our galaxy since the early universe. The Black Hole Mapper will measure masses and growth over cosmic time of the supermassive black holes that reside in the hearts of galaxies, as well as the smaller black holes left behind when stars die.

Trump says another novel aspect of SDSS-V is repeat observation, which he will be scheduling over the duration of the project as cadence coordinator, to help gather more data about the evolution of different features of matter near black holes.

“SDSS-V has more repeat observations as part of the plan. I would say that broadly in astronomy there is an emphasis on repeat observations,” he says. “For instance, black holes are fascinating – they are rips in space-time, and they are extremely exotic. Even one snapshot reveals how exotic they are, but they are also dramatically variable, and when we observe them day-to-day, week-to-week, year-to-year, we see dramatic changes in their emission, which we think correspond to dramatic changes just beyond the event horizon of the black hole. We are learning that you can reveal a lot about the physics of what is going on around black holes by watching them as a function of time.”

SDSS-V will operate out of both Apache Point Observatory in New Mexico, home of the survey’s original 2.5-meter telescope, and Carnegie’s Las Campanas Observatory in Chile, where it uses the 2.5-meter du Pont telescope. SDSS-V’s first observations were gathered in New Mexico with existing SDSS instruments, as a necessary change of plans due to the pandemic. As laboratories and workshops around the world navigate safe reopening, SDSS-V’s own suite of new innovative hardware is on the horizon—in particular, systems of automated robots to aim the fiber optic cables used to collect the light from the night sky. These will be installed at both observatories over the next year. New spectrographs and telescopes are also being constructed to enable the Local Volume Mapper observations.

Trump points out that another important aspect of SDSS, especially in a time of remote learning and researching, is the fact that data are made public and accessible.

“It is easy to access and mine the SDSS databases and make interesting studies,” he says. “They have wonderful tutorials for schools and for researchers to get started. They make it so easy for people to dive in. It is a very rich opportunity; it’s well organized and publicly shared.”

To learn more about the program, explore the data, or keep up with the research, visit https://www.sdss5.org/

This article first appeared online on UConn Today, November 2, 2020.

The passing of UConn Physics Professor Emeritus, Arnold Russek

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Arnold Russek, a theoretical atomic physicist, born July 13, 1926, in New York, passed away on October 13th, 2020, in Colorado. As a young man of 18, he served honorably as a radio engineer in the Pacific during WWII. He earned his Ph.D. at the Courant Institute at New York University in 1953, and taught physics for 40 years at the University of Connecticut, having Professor Emeritus status when he retired in 1992. Prof. Russek published notable works on processes on hydrogen beams and atomic collisions. He is remembered by many of his students as not only an excellent teacher but also a kind and supportive mentor.

 

 

AAS Author Interview with Gloria Fonseca Alvarez

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October 14, 2020 – AAS Author Interview Series

UConn graduate student Gloria Fonseca Alvarez was featured with a video in the Author Interview series produced by the American Astronomical Society (AAS):

 

In this video, Gloria talks about her work to understand the inner environments of black holes. The paper highlighted in the video shows that the orbits of emission-line gas around supermassive black holes are often smaller than expected from previous observations. We’re very proud to see Gloria’s exciting work recognized in the AAS Author Series!

Stretching Makes Superconductor

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October 12, 2020 – Kim Krieger – UConn Communications

When people imagine new materials, they typically think of chemistry. But UConn physicist Ilya Sochnikov has another suggestion: mechanics.

Sochnikov works with superconductors. Superconductors are materials that let electricity flow without losing energy. In a normal conductor — say, a power line — electric current is gradually whittled down by friction and loss. We lose as much as 90% of the electricity we generate this way. But an electric current could flow through a superconducting circuit forever, unchanging. Practical superconductors would make power grids and many devices, including new computers, much more energy efficient.

Chemists and metallurgists have experimented with different combinations of elements for years, trying to get superconductors that work at temperatures close to room temperature (most superconductors only work when they are super cold.) The idea is to come up with the perfect combination of elements that will have exactly the right density of electrons, at the right energies. When that happens, electrons pair up and move through the material in a synchronized way, even at temperatures above 77 degrees Kelvin, which is the temperature of liquid nitrogen. That is considered a high-temperature superconductor, because liquid nitrogen is cheap to produce and can be used as a refrigerant. But finding the right chemistry to make new and better high-temperature superconductors has been elusive.

Sochnikov and his students are thinking about it differently. What if mechanical changes such as squeezing or stretching could make a material a superconductor? Changing the chemistry is ultimately about changing the arrangement of atoms and electrons in a material. Mechanical stresses can do the same thing, in a different way.

Along with Physics Department students Chloe Herrera, Jonah Cerbin, Donny Davino, and Jacob Franklin, Sochnikov designed a machine to stretch a small piece of superconductor to see what would happen. They picked strontium titanate, a well-known material used in high-tech electronics applications as big and almost perfect crystals, which becomes a superconductor around 0.5 degrees Kelvin. That is ridiculously cold, colder even than liquid helium. But strontium titanate behaves in a very weird way when it is that cold. Its atoms polarize; that means they all oscillate in synchrony. You can imagine them bouncing gently up and down, all together. These oscillations have a tendency to link electrons together, helping them move as a pair–this is probably what makes it superconduct.

Sochnikov and the students in the group knew that stretching strontium titanate would change how its atoms oscillated. That, in turn, might change how the electrons moved. The machine that stretches the crystal is made from copper to conduct heat away from the crystal. Most of the rest of the workings are coated in gold to reflect heat from the outside. It uses three cylinders to cool the material; first to the temperature of liquid nitrogen (70K), then liquid helium (4K), then to a boiling mixture of helium-3 and helium-4 (due to weird quantum effects, it is even colder than regular liquid helium–just a few thousandths of Kelvin! Really close to absolute zero!)

The whole setup is suspended in a steel frame that floats on shock absorbers, to prevent any vibrations in the floor from disturbing the experiment.

When Sochnikov, Herrera, Cerbin, Davino, and Franklin did the experiment and looked at the results, they found that stretched strontium titanate becomes superconducting at temperatures 40% higher than normal. That is a huge increase, percentage-wise. They believe it is because stretching the material makes it easier for the atoms to oscillate, gluing the electrons together more firmly. Now, they are working to calculate what made the difference, and plan on testing it in other materials in the near future.

“Usually we control materials chemically. Here, we do it mechanically. This gives us another tool to bring superconductors closer to everyday life, and to discover new functionalities,” Sochnikov says.

This article first appeared online on UConn Today, October 12, 2020.

My Long-time Friend and Colleague, Prof. Cynthia W. Peterson

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When I arrived in Storrs from New York City in 1969 to teach physics at the University of Connecticut, one of the first colleagues I met was Dr. Cynthia Peterson. She had an infectious enthusiasm that appealed to me and my wife Anne. It turned out that Anne and Cynthia had both been students at Bryn Mawr College at the same time, another thing that bound us together. We remained colleagues and friends for decades until she finally retired in 2016, after nearly fifty years on the faculty. I felt she deserved a special retirement party on campus after all that time, and helped to facilitate it.

There are many memories: one is that she was the regular instructor in a large astronomy class year after year. This course continued from the time I came to Storrs into the present decade. Having an interest in astrophysics, I filled in for her to teach elementary astronomy for a year while she was on leave and I was mentored by her in preparation. This gave me an appreciation for the quality of her teaching and the effort she put into it.

Teaching for her was more than imparting facts: it included an introduction to research, how facts in science were discovered. An important part of the course was the hands-on observing sessions where students would use a telescope on the roof of the physics building to look at the moon, planets like Saturn, Mars and Jupiter, plus a number of distant galaxies. I had little experience in practical astronomy and Cynthia got me started on that. It is noteworthy that Cynthia and Jerry’s two children are named Celeste and Tycho.

I found out that outreach to the public and community was an important part of the astronomy course because of local interest. Cynthia conducted an extensive outreach program to the community, appearing on radio shows and sometimes on television. Working with her gave me an opportunity to devise some undergraduate research projects using the UConn roof-top telescopes. One project involved a survey of sunspots and observing the sunspot pattern moving which indicated that the sun is rotating slowly on its axis like the earth. Over the years, Cynthia helped many students; particularly female students, with similar research experiences.

One year, when Cynthia was up for promotion, we served together as co-advisors for a graduate student on a spectroscopy project involving experiments using an ultraviolet spectrometer the she had in her lab and a small ion accelerator in my laboratory. This project combined our expertise to provide a richer experience for the student. When our daughter Sarah reached high school, she worked one or two summers as an assistant to Cynthia on some research on dating pre-Columbian pottery samples through a study of the light they emit when heated to high temperature (thermoluminescent dating). The emitted light was due to damage to the material from cosmic rays over the years since the pottery was first fired. This mentoring gave Sarah an appreciation for science as well as a role-model for how to do it, that a father could not replace. Sarah later followed her mother and Cynthia to Bryn Mawr, graduating with honors; though not in science.

Not all our interactions were work related: we shared memberships in the Mansfield Family Recreation Association, which provided an affordable cooperative winter lodge in Northfield, Vermont (once the governor’s residence) in the heart of the ski country. Several families in Eastern Connecticut with teenage children were members that combined outdoor activity, winter and summer, with socializing in the evening. Cynthia and Jerry Peterson were particularly active in this: Cynthia served as Treasurer of the Association for many years.

The Physics Department at UConn had an annual hike up Mt. Monadnock (near Jaffrey, NH) during the height of the fall colors. We joined the Petersons for this event for several years, which featured a picnic on top and dinner on the way home.

In the last few years, with Cynthia and me both retired, UConn’s Physics Department has moved into more advanced astronomy, starting a graduate research program in that field and hiring several new faculty, initially including two women. Women in physics and astronomy faculty are still underrepresented. The program seems very popular with students, both undergraduate and graduate; its success has led to new funding and substantial research. At Cynthia’s retirement, I remarked in jest, but not entirely so, that it has taken three people to replace her.

She set the stage and provided a demonstration of student interest that helped justify the new program. She will be very much missed as a colleague and friend. She has left a strong legacy not only in the field of astronomy, but has been a particular inspiration for women in science more generally.

 

Winthrop Smith
Research Professor and Prof. Emeritus, Physics
University of Connecticut,
Storrs, CT. 06269-3046
Tel: (860)377-0941. Email: winthrop.smith@uconn.edu

New Physics Faculty: Erin Scanlon

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Erin Scanlon joins our Department in fall 2020 as Assistant Professor in Residence at the Avery Point Campus. Erin comes to UConn with an impressive track record of university teaching experience and scholarship in physics education research (PER).

After earning a master’s degree in physics from Georgia Institute of Technology, Erin joined the faculty at Texas Lutheran University from 2012-2017 where she developed and taught introductory physics courses and the associated labs. In parallel to that, Erin pursued PhD in the developmental education doctoral program at the Texas State University, the only program of its kind in the nation, where she earned her PhD in 2017 receiving the 2018 Texas State University Outstanding Dissertation Award. Subsequently Erin accepted a position as a preeminent postdoctoral scholar at University of Central Florida in the group of Dr. Jackie Chini. Erin is a renowned expert in the field of physics education research. Her research, supported by intra- and extra-mural grants, was published in the top PER and STEM education journals. Recently Erin’s research focused on two main streams: investigating how studio physics is implemented across multiple institutions in the nation, and investigating how to support people with disabilities in STEM fields.

Erin is one of the founding steering committee members of the APS Inclusion, Diversity, and Equity Alliance (APS-IDEA) launched by APS in summer 2020. This new APS initiative is a world-wide alliance to support departments, national labs and other institutions to identify and enact strategies for improving equity, diversity and inclusion which is much needed in physics. APS-IDEA is a great success with currently more than 90 admitted teams including UConn, see the article on APS-IDEA (to avoid conflict of interest our application was not reviewed by Erin). Erin is also the vice chair of the Physics Education Research Leadership and Organizing Council (PERLOC) which is the leadership body for the physics education research community and founded the Conference Accessibility Working Group.

Erin is committed to outreach and initiated at the Texas Lutheran University highly successful outreach events, called Family Physics Night, which brought together members from the university and local community members. Once settled in, Erin is looking forward to start similar outreach and research activities. Erin moved to Connecticut with her husband Matt who is also a scholar in PER and teaches physics at post-secondary level. We are excited to welcome Erin as a physics faculty in our department, and look forward to working with her.