News

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

International Summer School “Strong interactions beyond simple factorization”

May 27-June 5 UConn Physics Department hosted an international summer school Strong interactions beyond simple factorization: collectivity at high energy from initial to final state. The school was supported by an NSF grant to Prof. Kovner and was devoted to modern approaches to the physics of high energy hadronic and heavy ion collisions.

Amelia Henkel, Graduating President of the Undergraduate Women in Physics Club, speaks about her time at UConn

 

Amelia Henkel, graduating Double Major in Physics and Human Rights, and President of the Undergraduate Women in Physics Club, speaks on the CLAS website about her passion for physics and human rights, and how she mastered challenges in her remarkably interdisciplinary curriculum. “We really need to interact with other disciplines,” says Amelia, “because that’s when physics has the opportunity to make a real impact on the rest of the world.” Her broad research interests range from A to W: from Astronomy to Women’s, Gender, and Sexuality Studies. “Respecting and promoting human rights is a prerequisite to realizing our full potential as human beings,” says Amelia. Physics as a discipline has made progress to become more inclusive, but many groups remain minorities including women. In daily college life in physics departments female students still face “microaggressions and discriminatory practices” which are often unintended and unconscious but nonetheless damaging and frustrating.  As the President of the Undergraduate Women in Physics Club, Amelia helped to organize “events that promote community cohesion and inform the students about the nature of some of the barriers that exist in physics and in STEM, while talking about how we can overcome them.” The recent department-wide event Women in Physics Colloquium organized by Amelia was thought provoking and well-received. The percentage of women earning a Bacheleor’s Degree in Physics from UConn, though slowly increasing and compatible with the national average of about 20% published by APS, is far away from where we wish to be. But the efforts of students like Amelia contribute to improving the situation.  Many thanks to Amelia whose commitment helps to make our department better.

Read more about Amelia on the CLAS website. A short summary of her story is in UConn Today.

Astronomers Assemble View of Evolving Universe

 – Donna Weaver & Ray Villard, Space Telescope Science Institute

The University of Connecticut’s Katherine Whitaker is part of a team of astronomers who have put together the largest and most comprehensive “history book” of the universe from 16 years’ worth of observations from NASA’s Hubble Space Telescope.

This image, a mosaic of nearly 7,500 separate Hubble exposures, presents a wide portrait of the distant universe and contains roughly 265,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the universe’s birth in the Big Bang. (Space Telescope Science Institute Image)

The deep-sky mosaic provides a wide portrait of the distant universe, containing 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. The tiny, faint, most distant galaxies in the image are similar to the seedling villages from which today’s great galaxy star-cities grew. The faintest and farthest galaxies are just one ten billionth the brightness of what the human eye can see.

The image yields a huge catalog of distant galaxies. “Such exquisite high-resolution measurements of the legacy field catalog of galaxies enable a wide swath of extragalactic study,” says Whitaker, the catalog lead researcher. “Often, these kinds of surveys have yielded unanticipated discoveries that have had the greatest impact on our understanding of galaxy evolution.”

The ambitious endeavor, called the Hubble Legacy Field, also combines observations taken by several Hubble deep-field surveys, including the eXtreme Deep Field (XDF), the deepest view of the universe. The wavelength range stretches from ultraviolet to near-infrared light, capturing all the features of galaxy ‘assembly over time.

“Now that we have gone wider than in previous surveys, we are harvesting many more distant galaxies in the largest such dataset ever produced,” says Garth Illingworth of the University of California, Santa Cruz, and leader of the team. “This one image contains the full history of the growth of galaxies in the universe, from their times as infants to when they grew into fully-fledged ‘adults.’”

Illingworth says he anticipates that the survey will lead to an even more coherent and in-depth understanding of the universe’s evolution in the coming years.

The deep-sky mosaic provides a wide portrait of the distant universe, containing 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang.

Galaxies trace the expansion of the universe, offering clues to the underlying physics of the cosmos, showing when the chemical elements originated and enabled the conditions that eventually led to the appearance of our solar system and life.

This new wider view contains 100 times as many galaxies as in the previous deep fields. The new portrait, a mosaic of multiple snapshots, covers almost the width of the full Moon, and chronicles the universe’s evolutionary history in one sweeping view. The portrait shows how galaxies change over time, building themselves up to become the giant galaxies seen in the nearby universe. The broad wavelength range covered in the legacy image also shows how galaxy stellar populations look different depending on the color of light.

The legacy field also uncovers a zoo of unusual objects. Many of them are the remnants of galactic “train wrecks,” a time in the early universe when small, young galaxies collided and merged with other galaxies.

Assembling all of the observations was an immense task. The image comprises the collective work of 31 Hubble programs by different teams of astronomers. Hubble has spent more time on this tiny area than on any other region of the sky, totaling more than 250 days.

The image, along with the individual exposures that make up the new view, is available to the worldwide astronomical community through the Mikulski Archive for Space Telescopes (MAST), an online database of astronomical data from Hubble and other NASA missions.

The new set of Hubble images, created from nearly 7,500 individual exposures, is the first in a series of Hubble Legacy Field images. The team is working on a second set of images, totaling more than 5,200 Hubble exposures, in another area of the sky.

In addition, NASA’s upcoming James Webb Space Telescope will allow astronomers to push much deeper into the legacy field to reveal how the infant galaxies actually grew. Webb’s infrared coverage will go beyond the limits of Hubble and Spitzer to help astronomers identify the first galaxies in the universe.

The Hubble Legacy Fields program, supported through AR-13252 and AR-15027, is based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy Inc., under NASA contract NAS 5-26555.

This article first appeared in UConn Today on May 2, 2019.

UConn Physics Professor elected to AAAS

UConn physics professor Nora Berrah has been elected to the historic and prestigious American Academy of Arts and Sciences. This year, more than 200 individuals were elected to the academy with compelling achievements in academia, business, government, and public affairs. Berrah, who was head of the physics department from 2014 to 2018, has been recognized for her distinguished contributions to the field of molecular dynamics, particularly for pioneering non-linear science using X-ray lasers, and spectroscopy using synchrotron light sources.

Using big lasers – like the Linac Coherent Light Source at SLAC National Laboratory on the campus of Stanford University, the most powerful X-ray laser in the world – Berrah’s research explores transformational changes occurring inside molecules when exposed to ultra-intense beams of light. In particular, she investigates physical molecular processes that occur at the femtosecond time scale: one quadrillionth, or one millionth of one billionth, of a second.

“The American Academy for Arts and Science honors excellence and convenes leaders to examine new ideas, and that it is a high honor bestowed on me,” Berrah said.

The 2019 class includes poet and Andrew W. Mellon Foundation president Elizabeth Alexander; chemical and biological engineer Kristi S. Anseth; artist Mark Bradford; gender theorist Judith Butler; economist Xiaohong Chen; academic leader and former Governor Mitchell E. Daniels Jr.; neuro-oncologist Robert B. Darnell; The Atlantic journalist James M. Fallows; author Jonathan Franzen; cell biologist Jennifer Lippincott-Schwartz; data science and McKinsey & Company technology expert James Manyika; former First Lady Michelle Obama; Cisco Systems business leader Charles H. Robbins; mathematician Sylvia Serfaty; philosopher Tommie Shelby; actress and playwright Anna Deavere Smith; and paleoclimatologist Lonnie G. Thompson.

This post has been transcribed from the announcement on UConn Today.

UConn Astronomers React to First Photo of a Black Hole

credit: Event Horizon Telescope collaboration

This image is the first ever taken of a black hole, captured by the Event Horizon Telescope (EHT) project. The black center is a direct view of the event horizon of a supermassive black hole with a mass of 6.5 billion times the Sun, lying at the center of the Virgo cluster of galaxies. The bright ring is emission from hot gas just above the event horizon, with an asymmetric shape caused by gravitational lensing of light in the strong gravity of the black hole. The EHT collaboration captured the image using a network of 8 radio telescopes that spanned the Earth, effectively creating a planet-sized interferometer.

For more information, see the full NSF press release:

This result directly impacts research in galaxy evolution and cosmology that is being carried out at UConn. The following comments from UConn Astrophysics researchers indicate the level of interest that this result has generated within the international Astrophysics community.

This is a stunning technical achievement. Supermassive black holes are the most extreme objects in the Universe, bizarre rips in spacetime that lie in the center of every massive galaxy. But despite their extreme properties, black holes have a remarkably simple mathematical description, with just a few numbers describing all of their vital properties: mass, size, and spin. Until now, the only way to measure black holes was through indirect methods, like my own research program that uses the timing of light echoes in the surrounding gas. The Event Horizon Telescope black hole image is a tremendous first step in a new understanding of extreme gravity and the detailed astrophysics of black holes. – Jonathan Trump, Assistant Professor
I am fascinated by this result and how we can actually see a direct image of a black hole that is a trillion times our distance to the Sun. This is truly an amazing result for human beings achieved within the limitation of our observational instruments. As an observational astronomer who works with black holes, this result also opens up new possibilities to learn about their unknown features such as black hole spin that could revolutionize our understanding of black hole physics. – Yasaman Homayouni, Graduate Student
This result is a beautiful demonstration of what is possible when the global community works in concert towards a scientific goal. Sometimes the greatest discoveries are not found by the biggest new telescopes in space, but through creative thinking, years of dedicated effort, and big data techniques, building upon what we have here on Earth. – Cara Battersby, Assistant Professor
It is truly extraordinary to be able to provide this new evidence for Einstein’s ideas on space and time through observations made no less than one hundred years since he first proposed them. As to the discovery itself, there are two aspects to black holes, one is that they pull everything in, and the other is that they do not let anything out. With nothing being able to get out, they thus look black to an observer on the outside, to thereby give them their black hole name. Now for many years we have had evidence of things falling into black holes, but had never previously had any evidence that things cannot get out. These new data show a fireball ring of things falling in, with the ring surrounding a black space in the center where nothing can get out. We thus confirm that indeed nothing can escape a black hole. – Philip Mannheim, Professor

For more about this topic, see this recent article in the Daily Campus, UConn Astronomy Community Responds Joyously to M87 Black Hole Image.

2 for the price of 1: UConn researcher finds new mechanism making double ionization an efficient process

Schematic of dICD

An international research team headed by Dr. Aaron LaForge from the research group of Prof. Nora Berrah in the Physics department at UConn has recently discovered a new type of decay mechanism leading to highly efficient double ionization in weakly-bound systems. The team has published its results in the science journal “Nature Physics”.

Ionization is a fundamental process where energetic photons or particles strip an electron from an atom or molecule. Normally, a much weaker process is double ionization, where two electrons are simultaneously emitted, since it requires higher-order interactions such as electron correlation. However, these new results show that double ionization doesn’t necessarily need to be a minor effect and can even be the primary ionization mechanism thereby getting two electrons for the price of one.

The enhancement is likely due to double ionization proceeding through a new type of energy transfer process termed double intermolecular Coulombic decay, or dICD, for short. The experiments were performed at the synchrotron, Elettra, in Trieste, Italy. There, electrons are accelerated to near the speed of light and then rapidly undulated through an alternating magnet field. In this way, the electrons emit short wavelength light which is needed to trigger dICD. The researchers produced superfluid helium droplets, which are cryogenic, nanometer-sized matrices capable of attaching various atomic and molecular species in order to perform precise spectroscopic measurements. In this case, dimers consisting of two alkali metal atoms were attached to the surface of helium droplets. The dICD process, schematically shown in Fig. 1, occurs through an electronically excited helium atom (red), produced by the synchrotron radiation, interacting with the neighboring alkali dimer (blue and white) resulting in energy transfer and double ionization. Although an alkali dimer attached to a helium nanodroplet is a model case, dICD is potentially relevant for any system where it is energetically allowed.

dICD belongs to a special class of decay mechanisms where energy is exchanged between neighboring atoms or molecules leading to enhanced ionization rates. Seemingly ubiquitous in weakly-bound, condensed phase systems such as van der Waals clusters or hydrogen-bonded networks like water, these processes can contribute to radiation damage of biological systems by producing particularly harmful low-energy electrons. dICD could strongly enhance such effects through the production of two low-energy electrons for each intermolecular decay.

Original publication:

A. C. LaForge, M. Shcherbinin, F. Stienkemeier, R. Richter, R. Moshammer, T. Pfeifer & M. Mudrich, “Highly efficient double ionization of mixed alkali dimers by intermolecular Coulombic decay”, Nature Physics (2019) DOI: 10.1038/s41567-018-0376-5

Kate Whitaker wins the Sloan Fellowship!

Original UConn Today article here

Rising Star in Astrophysics Receives Sloan Foundation Fellowship

Kate Whitaker, assistant professor of physics, stands next to a telescope inside the observatory on top of the Gant Complex on Feb. 14, 2019. (Peter Morenus/UConn Photo)
Kate Whitaker, assistant professor of physics, stands next to a telescope inside the observatory on top of the Gant Complex on Feb. 14, 2019. (Peter Morenus/UConn Photo)

As an assistant professor of astrophysics, Kate Whitaker spends a lot of her time thinking about stars. Hundreds of billions of stars that comprise galaxies, to be more precise. But with a recent fellowship from the Alfred P. Sloan Foundation, it is Whitaker’s star that is shining brightly.

Whitaker is one of 126 outstanding U.S. and Canadian researchers selected by the Alfred P. Sloan Foundation to receive 2019 Sloan Research Fellowships. The fellowships, awarded yearly since 1955, honor early-career scholars whose achievements mark them as among the most promising researchers in their fields.

Valued not only for their prestige, Sloan Research Fellowships are a highly flexible source of research support. Funds may be spent in any way a Fellow deems will best advance his or her work.

“Sloan Research Fellows are the best young scientists working today,” says Adam F. Falk, president of the Alfred P. Sloan Foundation. “Sloan Fellows stand out for their creativity, for their hard work, for the importance of the issues they tackle, and the energy and innovation with which they tackle them. To be a Sloan Fellow is to be in the vanguard of twenty-first century science.”

According to colleagues, Whitaker certainly fits the bill as one of the brightest young minds at UConn and beyond.

“Kate’s record so far is truly impressive and speaks to her potential as a leader in her field,” explains Barry Wells, head of UConn’s Department of Physics. “It was my great pleasure to nominate her for a Sloan Foundation Research Fellowship, and I am thrilled they felt she was worthy of the prize.”

An observational extragalactic astronomer, Whitaker’s research tries to reveal how galaxies are evolving from the earliest times to the present day.

In addition to her position at UConn, Whitaker is also an associate faculty at the new Cosmic Dawn Center in Copenhagen, Denmark. Whitaker and her students actively collaborate with DAWN, working towards pushing our detection of quiescent “red and dead” galaxies even earlier in time.

She will be among the world’s first scientists to explore the universe using the new James Webb Space Telescope when it is launched in 2019, which she says will allow her to push into new frontiers of research.

Apart from that exciting work, Whitaker and colleagues Cara Battersby and Jonathan Trump were tasked with building a full-fledged astronomy program from scratch at UConn. Not only has their work exceeded expectations, the fruits of their labor are already beginning to emerge. Whitaker and colleagues have so far created five new astrophysics courses with two more slated for next year, established an official astronomy minor, and are operating a thriving research program that involves doctoral students, undergrads, and even local high school students.

“I am both thrilled at this opportunity and humbled to be named amongst such a prestigious cohort of scientists,” says Whitaker. “With the Sloan Foundation’s generous support, I aspire to continue to lead ground-breaking studies of the distant universe, the mystery of which will no doubt captivate our imaginations.”

The Alfred P. Sloan Foundation is a philanthropic, not-for-profit grant making institution based in New York City. Established in 1934 by Alfred Pritchard Sloan Jr., then-President and Chief Executive Officer of the General Motors Corporation, the Foundation makes grants in support of original research and education in science, technology, engineering, mathematics, and economics. A full list of the 2019 Fellows is available at the Sloan Foundation website at https://sloan.org/fellowships/2019-Fellows.

Goodwin School 3rd grade visits the Physics Learning Labs

About one mile from the Gant plaza, Goodwin Elementary School teaches some really bright kids. On January 15, 2019, science teacher Nancy Titchen and Goodwin teachers brought the entire 3rd grade class on a field trip to the Physics Learning Labs mock-up studio for some science fun. Students enjoyed a liquid nitrogen show, witnessed quantum effects in superconducting magnetic levitation, experienced mechanics concepts such as angular momentum, and learned about vibrations and the phenomenon mechanical of resonance. The expert hands of a star team of PhD students (Erin Curry and Donal Sheets) and new laboratory technicians (James Jaconetta and Zac Transport) ensured students had a great time and learned some interesting science. Big thanks to the staff and the Goodwin School!

Nora Berrah Named 2018 AAAS Fellow

Physics professor Nora Berrah has been named a 2018 Fellow of the American Association for the Advancement of Science (AAAS). Prof. Berrah has been recognized for her distinguished contributions to the field of molecular dynamics, particularly for pioneering non-linear science using x-ray lasers and spectroscopy using synchrotron light sources.

Prof. Berrah

View full story on CLAS website.

Hands-On Approach to Physics

Step into a fall 2018 class section of PHYS 1602: Fundamentals of Physics II, and you’ll find a scene that’s far from the large introductory science lectures common on most college campuses.

Students in PHYS 1602: Fundamentals of Physics II in a new Studio Learning Lab located in the Gant Science Complex on November 5, 2018. (Bri Diaz/UConn Photo)
Anna Regan ’21 (CLAS) utilizes a whiteboard to try out
solutions during her group’s problem-solving tutorial.
(Bri Diaz/UConn Photo)

To start, the class of 30 students sits at several triangular workspaces, which today are covered with wires, coils, magnets, and power supplies that the students are using to demonstrate electromagnetic induction. At the start of class, the instructors provided a short lecture before the students set off on their own problem-solving tutorials.

Now, the instructors move from group to group, stopping to answer questions, as students shuttle back and forth to the whiteboards that line the classroom walls.

It’s a scene that’s about to become common in UConn physics courses, thanks to renovations to the Edward V. Gant Science Complex, according to Barrett Wells, professor and head of the Department of Physics.

“We’re rebuilding our classes from the ground up,” he says. “It’s the basis for what we’re going to spread across most of our introductory courses.”

The curricular redesign, says Wells, will replace the typical large-lecture format with smaller classes, utilizing five new studio-style physics learning laboratories to be added to the Gant Science Complex in 2019. These changes will promote active learning, collaborative problem solving, and faculty-student interaction, he says.

“This is a trend we’re seeing in our discipline,” Wells says. “Restricting class size to promote students actively participating during class has been documented to help them achieve and learn more across the board.”

Lecture Meets Lab

Traditional science courses, including those in physics, typically consist of three weekly lectures that hold 100 to 200 students, with once-per-week lab sections where students practice the concepts they learn in lecture.

But this setup poses challenges for professors and teaching assistants to cover the material at the same rate, often causing lecture and lab sections to fall out of synchrony, says Diego Valente, assistant professor in residence of physics and instructor of Fundamentals of Physics II.

In addition, many physics concepts are difficult to teach within the logistical setup of a lecture, and the instructors may have a difficult time knowing whether students comprehend the material, says Valente.

To combat these issues, the Department of Physics piloted redesigned versions of Fundamentals of Physics I and II, the introductory sequence for physics majors, in the spring and fall of 2018, respectively.

Graduate teaching assistant Lukasz Kuna instructs PHYS 1602: Fundamentals of Physics II in a new Studio Learning Lab located in the Gant Science Complex on November 5, 2018. (Bri Diaz/UConn Photo)
Course instructor and Ph.D. student Lukasz Kuna ’14
(CLAS), ’17 MS assists a group that includes Ian Segal-
Gould ’21 (CLAS), far right. (Bri Diaz/UConn Photo)

The new courses, which will use the physics learning laboratories, merge the lecture and lab sections into three 2-hour class periods per week that hold up to 54 students. Classes are led by the same professor and graduate students.

“[The studio classrooms] allow instructors to interact with students more frequently and discuss concepts with them in depth,” says Valente. “Previously, hands-on group work was limited to lab courses. Now, every single day in class there’s some kind of group activity where students solve problems.”

Lukasz Kuna ’14 (CLAS), ’17 MS, a physics Ph.D. student and teaching assistant for Fundamentals of Physics II, agrees.

“We can present a topic that’s somewhat difficult to understand, and then attack it from all angles,” he says. “It certainly should be the way physics is taught, because it prepares you for more difficult problem solving.”

A Learning Community

The studio learning model also increases the amount of time students spend working collaboratively, says Valente.

Ian Segal-Gould ’21 (CLAS), a physics and mathematics major enrolled in Fundamentals of Physics II, says that the class fosters the collaborative problem-solving that is expected of professional physicists.

“In lecture-based courses, people look at the professor,” he says. “They’re not talking to each other, they’re not solving the problem—they’re looking at somebody else solve the problem. In the real world, physicists work together, so I think the interactive component to this course is on the right track.”

Physics major Megan Sturm ’21 (CLAS) says that working in small groups helps build camaraderie and exposes her to new ideas.

“I know at least half of the class, and it’s way easier to learn that way,” she says. “Someone else will ask a question or say something during the lab that I wouldn’t have even thought about.”

Sturm also says that she enjoys the frequency of interaction with the instructors, noting that Valente circulates through the class, asks students specific questions, and engages in hands-on work with them.

Physics major Megan Strum, far left, in PHYS 1602: Fundamentals of Physics II in a new Studio Learning Lab located in the Gant Science Complex on November 5, 2018. (Bri Diaz/UConn Photo)
Physics major Megan Sturm ’21 (CLAS) says that working
in small groups helps build camaraderie and exposes her to
new ideas. (Bri Diaz/UConn Photo)

“He’s way more approachable, so when I’m having trouble with things, I don’t have a problem going to office hours,” she says.

Kuna, who has taught for three years in the Department, says that the faculty-student interaction helps him better gauge how students are learning the material.

“Traditionally, if you’re teaching in a large lecture, you somewhat lose the students when they go to lab,” he says. “Here, you get to see where your class stands.”

New Opportunities

With a target completion date for phase one renovations set for fall of 2019, the Department is gearing up to redesign other introductory courses, including Physics for Engineers and Physics with Calculus, a general education sequence taken by many pre-med students.

“This is important because we offer courses to majors across the University, and we’re teaching more students each year,” Wells says.

“Our goal is to develop not just comprehension of physical concepts, but also transferable skills–things like communication through group work and computer programming, which students can use in their professional lives,” adds Valente.

He says that these investments in teaching and infrastructure give UConn an advantage in addressing instructional issues common at institutions across the United States.

“This is a really large-scale venture we are doing, something a lot of comparable institutions aren’t able to do,” Valente says. “It shows that UConn is making a big commitment to physics education.”

By: Bri Diaz, College of Liberal Arts and Sciences
This article was originally published in the UConn CLAS Newswletter, November 28 issue