Author: Richard Jones

Meet the Researcher: Carlos Trallero

 – Anna Zarra Aldrich ’20 (CLAS), Office of the Vice President for Research

When Carlos Trallero started his academic career in physics, he had no idea he would become a pioneer in a field of research that uses high-power lasers to investigate atomic and molecular physical phenomena.

Originally from Cuba, where there isn’t much funding for experimental research, Trallero began his academic career by studying theoretical physics. But as a senior graduate student at Stony Brook University, he got the chance to work in a lab doing experimental work and quickly recognized it was his true passion.

“I talked to a professor doing experimentation with ultra-fast lasers and I fell in love with it. And at first, I sucked at it — I was horrible,” says the professor of physics who is now working with four research grants funding separate investigations.

Trallero works with very short laser beams, with an emphasis on very short. The lasers he uses can pulse with attosecond precision. As a comparison, there are as many attoseconds in one second as there have been seconds in the entire history of the universe since the Big Bang.

It takes light half an attosecond to cross the orbit of hydrogen, the smallest atom. When trying to study something that fast, scientists need the kind of precision the lasers Trallero can offer. The goal of this research is to gain a better understanding of how electrons, one of the fundamental atomic building blocks in the universe, move and react to light. By understanding the physics of electron movement, scientists could improve the design of technologies like superconductors.

“The dream is to be able to perform logistical operations like a computer at the attosecond level,” Trallero says. “It would really advance computational speeds. If you could make as many calculations in a second as there have been seconds in the history of the universe – that’s an astounding number.”

His lab is now working to break the attosecond barrier into the zeptosecond barrier which is 1,000 times faster than the attosecond.

While some of the potential applications of this research remain unknown since the field is still in its infancy, Trallero views the premise of his research as creating basic knowledge. He is investigating the atomic and molecular phenomena which determine so many things in our universe but about which we still know relatively little.

From left to right, Edward McManus Michael Davino Carlos Trallero Brandin Davis Zhanna Rodnova Tobias Saule Rich Sadlon (Submitted Photo)
Members of Trallero’s lab from left to right, Edward McManus, Michael Davino, Carlos Trallero, Brandin Davis, Zhanna Rodnova, Tobias Saule, Rich Sadlon. (Carson Stifel (’21 CLAS)/UConn Photo)

One project funded by the Department of Energy has Trallero looking at the properties of atoms and molecules in the quantum world by harnessing light waveforms at the attosecond time scale through interferometry. Interferometers provide precise measurements of molecules using two beams of light which interfere with each other. The images produced by this technology will allow Trallero to find out information about the rotational dynamics of molecules.

“In the quantum world, properties of atoms and molecules are not as simple as in the real world,” says Trallero.

Another of Trallero’s grants, from the U.S. Air Force Office of Scientific Research, involves creating an incredibly bright beam. Trallero’s lab is working on taking electrons out of nanoparticles and then sending them back in, which will produce a bright, energetic light. “The process to study these dynamics has never been executed in this manner,” Trallero says.

Trallero is also working on two grants from the U.S. Navy,  including one that aims to develop infrared “body heat lasers.”

Through these grants, Trallero is developing a new class of laser which is only comparable to those found at large, multinational laser facilities like the European Light Infrastructure. Compared to the technology currently available to Trallero at UConn, this new class of laser will have almost 20 times more average power than the current laser.

Developing a laser of this caliber will be incredibly useful for studying phenomena that only occur a few times per shot of the laser in real time. The laser will enable researchers to probe the molecules with X-rays and ultraviolet rays to look at their structure and is being developed through a partnership with a Canadian company, Few-cycle, and a German company, Amphos. Researchers like Trallero are able to get advanced technology for a fraction of their retail value by doing research of interest for these companies, which are constantly trying to innovate in step with the science.

“We’re only paying a fraction of the price because the company is interested in showing they can develop this kind of technology,” Trallero says. “Showing they have the capacity and showcasing what we do with, and for, them helps them gain a customer base and it helps us make major advances in basic science at the same time.”

Trallero is also considering creating spin-off tech companies based on his university inventions with graduate students and postdocs. He has developed nanoparticle technology which can help transform molecules from a liquid to a gaseous state which could be beneficial for producing aerosols.

Trallero views physics as “the broadest science” since it has unique applications to math, engineering, chemistry and, even, biology. “I try to think about particular scientific questions in a different way than perhaps other people who have been working in this field for a long time do,” Trallero says. “Often we suffer from too much in-depth specialization.”

He wants to make use of the tools from every specialty he can, and he instills this same inclination in the students working in his lab.

“They don’t know what they’re going to face in the future and by having a broad skill set and a broad mindset they’ll be prepared for anything,” Trallero says. “You’re opening your mind to more possibilities.”

This article first appeared on UConn Today, August 19, 2019

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.

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.

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.

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 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

Workshop ‘Dynamic Quantum Matter’ organized by UConn faculty

Dynamic Quantum Matter, Entangled orders and Quantum Criticality Workshop
Dates: June 18- June 19, 2018

Sponsors

UConn, NSF, Nordita, Villum Center for Dirac Materials, Institute for Materials Science – Los Alamos, Wiley Publishers
           

Scope

The conference will focus on entangled and non-equilibrium orders in quantum materials. The 21st century marked the revolution of probing matter at the nano- to mesoscale and these developments continue to be the focus of active research. We now witness equally powerful developments occurring in our understanding, ability to probe, and manipulate quantum matter, in entangled orders and novel states, in the time domain. Recent progress in experimental techniques including x-ray optics, optical pumping, time resolved spectroscopies (ARPES optics), and in cold-atom systems has led to a resurgence of interest in the non-equilibrium aspect of quantum dynamics. The novel entangled orders that have nonzero “overlap” with more than one order parameter also have emerged as an exciting new direction for research in quantum matter. Entangled orders go beyond the conventional orders such as density and spin, and significantly expand the possible condensates we can observe. It is only because of the lack of experimental control, resolution, theoretical framework, and computational power, that the realm of entangled and quantum non-equilibrium remained largely unexplored until now. The time has come for us to turn full attention to these phenomena. Specific topics include: superconductivity and dynamics near quantum criticality, composite orders in correlated materials, effects of strain on quantum critical points, and superconductivity in STO. This conference will have a format of topical lectures, while leaving ample time for discussions.

Venue

Gurney’s Resorts | Newport, RI

Department, alumni celebrate career of Prof. Doug Hamilton

Friday afternoon on April 20, 2018 the UConn Physics Department held a colloquium in honor of Professor Douglas Hamilton on the occasion of his retirement from active service on the faculty. The colloquium was MC’ed by Prof. Jason Hancock, who surveyed the highlights of a career spanning four decades marked by notable accomplishments in research, teaching, and service. Several of Doug’s former students also presented tributes to their mentor, some in person, and some by video or written message, expressing their gratitude for what they learned from him, both by instruction and example. At the end of the hour, Doug presented some final comments, which were followed by a standing ovation in recognition of Doug’s many contributions to our field, our department, and the University. Doug, you will be missed!

-Richard Jones

Hands-on teaching of introductory physics gains momentum

Students in PHYS 1601Q, taught by Professor Jason Hancock, work during a lab that observes how an external mass can affect oscillation by producing torque. They use a device called an ioLab to record data, and use the data in a program called Mathematica for analysis. The lab was in the Edward V. Gant science complex on April 20, 2018. (Garrett Spahn/UConn Photo)

 

A recently renovated physics classroom in the Edward V. Gant Science Complex was built to pilot a new approach to physics education, integrating lecture with lab rather than the classical approach of separating these components.

Students and instructors apply concepts with hands-on activities throughout the lecture, practice new tools, and problem solve as a group. The space is equipped with whiteboards on every wall, and computers and projectors for each station. Though built for entry-level courses such as Physics 1601 and 1602, the end goal is to convert larger classes into this format as well, including entry-level engineering and biology classes, for a more interactive learning experience.

– Garrett Spahn ’18 (CLAS) & Elaina Hancock

In memoriam, George H. Rawitscher (1928-2018)

It is with great sorrow that we report the passing of our long-time colleague and friend, George Rawitscher on March 10, 2018, after a brief illness and just having passed his 90th birthday, which was celebrated with a cake at a meeting of the UConn Physics Department. George was born in 1928 in Germany, where his fa-ther was a distinguished Professor of Botany at The University of Freiburg. In 1934 his father, Felix Rawitscher who was Jewish, brought his family which in-cluded George’s mother, Charlotte Oberlander, his sister Erika, and George from Germany to Brazil to escape the Nazis. In Brazil, Felix established and chaired the Botany Department, which still bears his name, at the University of Sao Paulo.

George grew up in Sao Paulo, where he learned fluent Portuguese. From an early age he knew he wanted to be a physicist, and taught himself quantum mechanics from a book during high school. He graduated in physics and mathematics from the University of Sao Paulo in 1949, and he served as an Instructor at the Brazilian Center for Physical Research in Rio de Janiero for two years, receiving a Brazilian National Research Council Fellowship. While he was in the Center for Physical Research at Rio, he worked under Richard Feynman who was a visiting professor at the same institute. He told his grandson Nicholas that Feynman had made a big mark on his life, inspiring his approach to physics, and observing that he had the potential to become a “real” physicist, which he remained until the end of his life.

Following his time in Rio, George went to Stanford University as a graduate student in theoretical nuclear physics and mathematics. He received his Ph.D. in 1956, for a study of Fierz-Pauli spin 3/2 particles and the anomalous magnetic moment of the muon under Profs. Leonard Schiff and D.R. Yennie. His first paper had to do with the effect of the finite size of the nucleus on muon pair production by gamma rays.

While at Stanford, George met and later married Mary Adams, a fellow Stanford student, and they proudly raised two sons, Peter and Henry. Mary, a biochemist, died in 1980. In his later years, George was again happily married to Joyce Rawitscher in 2009, who passed away in 2016. Following his graduate work, George became an Instructor at the Physics Nuclear Structure Center (University of Rochester) for two years and then joined the Physics Department at Yale as Instructor, doing research in collaboration with Prof. Gregory Breit. He remained at Yale as Assistant Prof. of Physics until 1964. He joined the Physics Department at the University of Connecticut in Storrs as an Associate Professor and then became Professor of Physics from 1972. He retired in 2009 but remained at UConn as an emeritus Research Professor until days before his death, continuing to do active research in nuclear physics, computational physics and ultracold atomic collision physics until his final days.

Prof. Rawitscher received several prestigious academic honors including one of the early Research Fellowship awards from the Alexander von Humboldt Foundation (Germany) in 1964 and became a Fellow of the American Physical Society, nomi-nated by the Division of Nuclear Physics in 2016. During his tenure at the University of Connecticut, he took academic leaves at the Max Planck Institut fur Kernphysik in Heidelberg (1964-1966), the Laboratory for Nuclear Science at MIT (1972), as guest professor at the University of Surrey, England 1973, the University of Maryland (1987-1988) and served on the Board of Directors of Bates Users Theory Group at MIT (1982-1985) and the Executive Committee of the American Physical Society topical group on Few Body Systems and Multi-Particle Dynamics (1993-1995). He gave a number of invited presentations in nuclear theory at conferences, published approximately 88 refereed papers and numerous conference proceedings. His principal research interests involved scattering problems using non-local opti-cal models of nuclear processes, coupled-channel reaction mechanisms for nuclear break-up such as the (e,e’p) reaction, and virtual nuclear excitations. Recently he emphasized development of numerical methods such as Galerkin and spectral expansions for solving integral equations. He has applied some of these techniques to studies of ultracold atomic collisions as well as nuclear reactions. His most recent refereed papers (2015-2017) concerned “Revival of the Phase-Amplitude description of a Quantum-Mechanical wave function.”

Professor Rawitscher was an engaged and untiring participant both in his Department and in the general community up to the last moments of his life. He promoted public awareness and activism on ameliorating the effects of global climate change and he and his wife Joyce have been active in the peace movement. He was a member of the Storrs, CT Quaker Meeting. He was also active in community service in the Storrs area, for example serving on the Town of Mansfield Sustainability Committee. Recently he has been working on a nearly-finished book summarizing his lifelong expertise in numerical computational physics, under contract with Springer, with two younger colleagues from Brazil. George was a dedicated and effective undergraduate teacher and empathetic mentor to a large number of graduate students, colleagues and collaborators. George was a central member of the department for more than 50 years, and has earned a special place in our hearts forever. His inspiring presence and example will be very much missed at the University, amongst his family, friends and the community, and it was a great loss to see him go.