John Mather Looks to the Past and Keeps Moving Forward

Details

Published: Friday, September 03 2021 00:11

John Mather Credit: NASA/Chris GunnThe past contains lessons that cannot be learned in the present. And although the past is often like a hazy crystal ball that is challenging to interpret, it is still instructive if we want to understand ourselves and our position in the universe.

To understand the origins of our universe, cosmologists piece together the subtle, lingering clues of a past that predates humanity as well as Earth. To do so, they must look past our local galactic neighborhood and study distant parts of the universe that might be forever beyond humanity’s reach.

John Mather, a College Park Professor of Physics at the University of Maryland and a senior scientist at NASA, has pursued his curiosity about the origins of the universe and succeeded at peering into the furthest reaches of the past, earning a Nobel Prize along the way.

“We can't see the Earth's history,” Mather said. “But we can see examples way out there. So what happened to make it possible to go from the Big Bang to Earth? We have a story of how that would happen. But most of it’s made up—most of it’s imaginary. So we have to check it by actually looking.”

Later this year, Mather will add a new chapter to his storied career. After decades of work, NASA is launching a revolutionary instrument into space, the James Webb Space Telescope—and Mather is the senior project scientist. The Webb telescope is bigger than the Hubble Space Telescope or any other telescope ever launched. It has about 6.25 times more area dedicated to collecting light than the Hubble, and it is designed to reveal for the first time sights of the primordial formation of some of the earliest stars and planets in the universe. Mather has spent the last quarter of a century helping make this ambitious project a reality.

The Dazzling Past

Mather shared the 2006 Nobel Prize in physics for uncovering secrets in the ancient, invisible remains of some of the universe’s first light, captured using the NASA Cosmic Background Explorer (COBE) satellite. This primordial light is called cosmic microwave background radiation and is constantly bombarding Earth (and every other part of the universe) from every direction. The ancient light is a dim but persistent messenger from that long-gone age, and it provides a unique window into the universe’s earliest moments.

COBE revealed that this radiation was a cosmic fingerprint with subtle variations. And that fingerprint proved to be the vital clue needed to establish the Big Bang theory as the accepted explanation for the birth of our universe (although Mather isn’t fond of the firework imagery summoned by that name for the beginning of an expanding, infinite universe).

Scientists think that the uneven pattern observed in the radiation resulted from the early universe being hotter and denser in some areas than others. This revelation is researchers’ main lead as to why matter ended up clumping together into stars, planets, galaxies and all the other objects that fill our universe. Those initial hot and cold pockets were the first dominoes that led to Earth and the rest of the dynamic universe we see today.

Reflecting on his fruitful career, Mather said that he thinks successful science, like the COBE mission, is the result of teamwork, a little bit of luck and pursuing your curiosity despite adversity.

For instance, COBE grew directly out of some of Mather’s graduate work that delivered disappointing results. He and his colleagues first tried measuring the cosmic background radiation from White Mountain in California. They learned a little bit about the radiation, but the tumultuous atmosphere prevented them from seeing details that could tell them about the early universe.

So they tried even greater heights—literally—by sending the measurement equipment up 25 miles using a balloon. The first flight failed to produce any results, and the next attempt didn’t happen until after Mather graduated. When the balloon-borne equipment finally managed to successfully collect data, it still lacked the desired precision.

Despite these troubles, the idea stuck in Mather’s head, and the project unexpectedly got a new life when NASA called for proposals for satellite experiments in 1974, just five years after the Apollo landing.

“I said, ‘Boss, my thesis project failed, we should try it in outer space,’” Mather said. “So he said, ‘We'll write a proposal.’ And that kept on not losing. At every possible place where you could be stopped, we found a way to keep on going. So 15 years later, it was launched.”

The data collected by COBE finally revealed the subtle details needed to interpret the radiation and left Mather and the rest of the scientific community with plenty of work to do. Those early hot and cold spots are just part of the story of the origin of everything.

Mather continued to investigate the origins of the universe and, in 2011, became an adjunct professor at UMD in addition to working at NASA. His current work is still unraveling the mystery of what the formative years of the universe looked like, and this time, with the help of a massive team, he hopes to get a look at the formation of some of the earliest galaxies.

An Unfolding Story

Mather recalled getting started on the Webb telescope with a call in 1995 asking if he wanted to work on a new telescope project that NASA was considering.

“Of course, I said, ‘Yes, that would be the coolest thing.’” Mather said. “And so that's what I've been doing ever since.”

Mather and his colleagues developed a plan for a telescope to observe things that are invisible to COBE, Hubble and every other satellite ever launched. The goal is to see more than 13.5 billion years into the past (when the universe was only about a couple of hundred million years old) and to take baby pictures of our universe that show the formation of the earliest galaxies and how they birth stars.

“One of the great mysteries is what was it like back then,” Mather said. “And we've never been able to see. The telescopes that we have are not powerful enough and do not observe at the right wavelength. So you just can't tell.”

The Webb telescope will gaze into that distant past by collecting light that is mostly invisible to the human eye. Light travels as waves of electric and magnetic fields, and the color of the light is determined by the distance between the wave peaks. The Webb telescope will look at the longest light waves humans can see—red—and the invisible light that is even more stretched out—infrared. (Infrared light is given off by human bodies and many other objects and is what night vision goggles detect.)

These long waves interest cosmologists because the universe is expanding, and as it expands, it also stretches out light. Light that starts out as blue (the shortest light we see well) gradually becomes yellow and then red and eventually infrared (and continues getting stretched into even longer, harder-to-detect wavelengths). Any light that has been traveling for billions of years since the birth of early galaxies has had plenty of time to stretch out.

We can’t see the past of our own corner of the universe, but by collecting and interpreting this stretched light, we can see the past of the far-distant part of the universe that the light came from.

The Webb telescope will be a revolutionary tool in observing the ancient and distant universe to check if our theories about that primordial time are correct. It is a big project that goes beyond the efforts of just NASA. The mission is a collaboration with the Canadian Space Agency and the European Space Agency and involves scientists from 14 countries, 29 U.S. states and the District of Columbia.A full-scale model of the James Webb Space Telescope being constructed at Battery Park in NYC for the 2010 World Science Fair. (Credit: NASA)

As the Webb telescope’s senior project scientist, Mather works with other scientists to identify what the telescope needs to do to make new discoveries and then works with engineers and managers to turn those grand visions into reality.

“I am at the interface between two worlds, and it's a very interesting place to be,” Mather said. “Of course, the work is really done by the participants saying, ‘Well, this is what my idea is,’ and somebody else says, ‘Well, I have a different idea.’ And then we have another idea. And then we have discussion, and maybe a little bit of hand-to-hand combat. Sometimes actually, instead of hand-to-hand combat, we have a vote, but that's not usually done, because usually it's pretty clear what is needed.”

This back-and-forth has been a lengthy process. By 2009, 14 years after Mather got involved in the project and five years after construction started, NASA targeted a launch date in 2013. But the project has suffered repeated delays. Technical difficulties with the telescope and complications from the COVID-19 pandemic contributed to recent delays. Now, the long-awaited launch is looking promising for the end of 2021.

“There's an awful lot of translation from the wish into a plan,” Mather said. “The Webb has taken about 25 years since that first phone call that I got. And most of that wasn't building; most of that was deciding what to build. When you're reaching so far beyond where anybody has ever been, you can't just draw a sketch and say, we'll build that. You have to say, ‘This is the set of inventions that we require, please go make those inventions, and then we'll decide something.’ So that took a good, long time just to even get started on the inventions.”

The team’s work includes making the telescope capable of maintaining a difference of 600 degrees Fahrenheit between the parts most heated by the sun and the coldest instruments with cooling systems and a tennis court-sized parasol. The giant parasol (or as NASA calls it, a “sunshield”) and a gold-covered mirror that is more than 21 feet across are made to fold up like origami for the rocket launch and then to unfold in space.

The team’s inventions and clever solutions combine into a telescope expected to be good enough to detect the amount of heat given off by a bumble bee from as far away as the moon is from Earth. All of the technology is designed to be deployed about a million miles from Earth (about 4 times farther from Earth than the moon). If everything goes according to plan, it will take about six months from launch to get the telescope into location, set up, tested and ready to perform science.

A Promising Future

The Webb telescope will let scientists do more than peer into the early history of the universe, though. Infrared light should let them peek into cosmic dust clouds that block visible light and study the formation of stars and planets that are not too far from our solar system (which formed more recently). It might even reveal new details of neighboring celestial objects like the moons of Saturn or the dwarf planet Pluto. It will also be able to detect water vapor and other chemicals in the atmospheres of planets outside our solar system.

Researchers from all over the world have the chance to suggest how to best use this technological marvel. Of the proposals selected for the first year of the telescope’s observation, about 10% came from students. Just as Mather’s proposal for the COBE satellite launched his success, other stellar careers might take off with this new telescope.

Mather said he is proud that the Webb telescope mission is providing opportunities to early-career scientists. And despite the Webb telescope keeping him busy at NASA’s Goddard Space Flight Center in nearby Greenbelt, Maryland, he still values his connection to the university.

“We have a pretty strong connection between NASA Goddard and the University of Maryland,” Mather said. “Especially, we cooperate in high-energy physics, astronomy, cosmic rays, X-rays, gamma rays and things that people at the university have a lot of expertise in. I'm glad to be a member of the department. And I look forward to talking with people that I have shared interests with. I invite people to contact me about the Webb telescope and about any other ideas that they have, especially for space astronomy.”

The best advice Mather says he can offer students is just telling them what worked for him. He credits his success to finding people he liked to work with and persistently tackling interesting questions with them despite setbacks.

“I can't say that setbacks are fun,” Mather said. “But in our business of science, they're all the time. Treat failures as setbacks and learning opportunities and think about what else you would do next. While I was working on the balloon payload, I had in the back of my mind, ‘Well, the problem with this balloon is that it's not in outer space.’ And when NASA asked for proposals, I said ‘Well, I've got an idea.’ So when a good idea comes to you and you can't do it now, keep it. And maybe you'll get a chance later. The future is long. Probably infinite.”

Written by Bailey Bedford

Elevating the Humble Neutrino

Details

Published: Friday, September 03 2021 00:11

Rabi Mohapatra at the 2016 campus convocation

Rabindra Mohapatra wants “neutrino” to be a household word.

“This is a very fascinating particle,” he said. “Neutrinos are so tiny, there are billions of them passing through us every second, and they interact so weakly, we even can’t tell. But the neutrino is pretty much responsible for creating the whole universe, everything we see has an imprint of the neutrino.”

Mohapatra, a Distinguished University Professor of Physics at the University of Maryland, has been theorizing the origins and mass of neutrinos for 40 years. Last fall, he published a book targeted toward non-scientists called “The Neutrino Story: One Tiny Particle’s Grand Role in the Cosmos.”

As a theoretical physicist, Mohapatra proposes mathematical explanations for how the universe works, specifically how the tiny particles that make up the universe and the forces that control them interact to create all the matter we can see—and even the dark matter we can’t see. It may seem like heady stuff for a village boy from India, but Mohapatra’s path followed a logical trajectory for someone in his shoes.

“I was always interested in science, from the very beginning,” he recalled. “But we didn’t have too many instruments to work with in my school, so experimental physics was not the way I could go to explore my interests. Mostly then, my interests became theory based, and I studied math and science books.”

Mohapatra was especially inspired by popular science books like “One Two Three . . . Infinity,” which was written by Russian theoretical physicist and cosmologist George Gamow, who helped develop the Big Bang theory.

“One of the things that inspired me quite a bit from Gamow’s books and other popular science books was learning that something so abstract as mathematical formula could be connected to the simple things we observe,” Mohapatra said. “And my father sort of pushed me in that direction, too, because he was very interested in math. In fact, my father had gone to college, which was quite an amazing thing in the 1930s.”

The younger Mohapatra earned his bachelor's degree in physics in 1964 from Utkal University in Bhubaneswar, India, and his master's degree in physics at the University of Delhi in 1966. The same year, he traveled around the globe to New York where he earned his Ph.D. in physics at the University of Rochester in 1969.

After completing postdoctoral fellowships at Stony Brook University and UMD, Mohapatra joined the physics faculty at City University of New York. In 1983, he returned to the Department of Physics at UMD as a professor, and he has been here ever since.

Over his career, Mohapatra has traveled the world for conferences and talks. He accepted multiple visiting professorships at institutions like the Max Planck Institute for Physics and the Technical University of Munich in Germany, CERN in Switzerland, and Los Alamos National Laboratory and Brookhaven National Laboratory in the U.S.

Mohapatra is known throughout the world for his seminal theories on neutrino masses, which include support for new particles and a unifying theory that governs the behavior of all matter in the universe. Along the way, he has published 450 peer-reviewed research papers and received numerous awards such as the Distinguished Scientist Award from the American chapter of the Indian Physics Association in 2000 and the prestigious Humboldt Prize in 2005.

At UMD, Mohapatra was awarded a Distinguished Faculty Research Fellowship in 1995-96 and was named a Distinguished Scholar-Teacher in 2000. In 2016, he was honored with the title Distinguished University Professor, the highest academic honor bestowed by the university.

And yet, Mohapatra says some of his proudest accomplishments are those in which he passed on his passion and expertise to young scientists.

“I feel fortunate to have worked with them,” he said of the 25 Ph.D. students he mentored at the City University of New York and UMD. “They have been really inspiring. Many of them are now faculty members at universities all around the world, and that’s one of the most satisfying things about my career.”

Although Ph.D. students invigorate Mohapatra’s scientific mind, he also finds joy in sharing his enthusiasm with students who come to him with no knowledge of his field. This joy drives him to teach large introductory physics lecture courses.

“They’re usually a lot of work because they’re such large classes,” he said. “I like to teach them because it’s a way to communicate with younger people who have some of the most interesting ideas. I try to sneak in some of these higher concepts and get them thinking about these things, and hopefully some of them grab on to it.”

That same desire to reach a broader audience is what motivated him to write his latest book as well. Mohapatra had already written a textbook on supersymmetry and co-authored another on neutrino masses, which have both gone on to third edition printing. But he was encouraged by his wife to write a book that would inspire science enthusiasts in high school or college to appreciate the beauty and significance of neutrinos.

But it was a challenge. The seminal theories Mohapatra is most known for and spends much of his time working on can be a little mind-bending to the average person.

In his theories of left-right symmetry, for instance, Mohapatra tackles a long-standing question about why certain particles only appear to have one of two known presentations in certain circumstances. The presentation in question is known as right- or left-handedness and refers to the direction in which a particle spins relative to the direction it is moving.

For example, if you make a “thumbs up” gesture, in which your hand is a particle, your thumb indicates the direction the particle travels, and the curl of your fingers indicates the direction the particle spins. A right-handed “thumbs-up” is the mirror image of a left-handed one. And for some unknown reason, physicists only see left-handed neutrinos.

Where it gets complicated is in the search for the left-handed neutrino’s anti-matter particle. Every elementary particle has an anti-particle that has the same mass and spin but opposite charge (or in the case of neutrinos, which are electromagnetically neutral, the anti-particle has an opposing lepton number.)

Scientists have yet to observe a left-handed anti-neutrino, the counter particle to the left-handed neutrinos they’ve seen. However, they observed anti-neutrinos, but they’re all right-handed. This breaks the mirror symmetry of nature, but Mohapatra believes the problem is a matter of scale. He hypothesizes that all particles, including right-handed neutrinos and left-handed anti-neutrinos, do exist in nature. We just can’t see the right-handed neutrinos now because they are very heavy and show up at a higher energy scale.

“Meaning, at some higher energy scale, everything has symmetry between left and right, but when we come to the scale we can observe and we do an experiment involving the neutrino, things look only one-sided, where we only see the left side and not the right,” he said.

Experimentalists have been working on testing these theories, and their observation of neutrino mass provides some indications that Mohapatra could be correct.

Another one of Mohapatra’s ideas that experimental physicists are working hard to understand is called the seesaw mechanism for explaining neutrino mass.

Physicists have long pondered how neutrinos can have so little mass. (They are a billion times lighter than protons.) Mohapatra proposed that the right-handed neutrino that has yet to be observed acts as the right-handed neutrino’s heavy, unseen partner.

“It’s a bit like a seesaw on the playground,” he said. “When one child goes up, it is because another heavier child is sitting on the other side. So, the idea is that if there is the heavy right-handed neutrino sitting on the other side of the world in some sense, then this particle, the neutrino we see, becomes light. It’s not a very clear explanation but that’s probably the best one can do.”

Of course, that may be all one can do in a sentence. Mohapatra draws a clearer picture of the seesaw mechanism in his new book, which hit the shelves in November 2020. By September 2021, it was already selling well as Amazon reported just 10 left in stock, with more in print. That’s not a bad start for someone on a quest to make “neutrino” a household word.

Written by Kimbra Cutlip

Research Projects Open Doors for High School Students

Details

Published: Friday, September 03 2021 00:11

Before this summer, going to college seemed impossible to Casey Claveria, a rising senior at Quince Orchard High School in Gaithersburg, Maryland. A problem-solver at heart, Claveria was set on a career in STEM but did not know how to get there. A University of Maryland program called PROPEL—Physics Research Opportunity for Promoting Equity in Learning—changed that.

PROPEL aims to increase the number of underrepresented minorities in physics by exposing high school students to cutting-edge university research. When UMD’s Department of Physics established its Climate Committee in 2020 to ensure a welcoming and supportive environment, graduate student commit PROPEL participants visited campus toward the end of their summer program to tour physics labs. From left to right: Casey Claveria, Kalkidan Michael, Peter Elgee, Landry Horimbere, Ananya Sitaram.tee members Landry Horimbere (B.S. ’16, physics; B.S. ’16, physical sciences) and Ananya Sitaram decided to set the program into motion.

“PROPEL is a really important step toward addressing the transition between high school and undergrad and getting more students interested in doing physics in college by showing them what you can do with physics,” Sitaram said.

In fall 2020, 17% of undergraduate physics majors at UMD were underrepresented minorities and 20% were female. The Climate Committee quickly acknowledged the importance of investing time and resources in the high school-to-college pipeline.

“There’s direct value in recruiting underrepresented students and giving them a research experience. It demystifies physics, engineering, mathematics for students early on,” Horimbere said. “If you go into physics and take the classes, you’ll learn a lot of formal material, but it’s not as involved or interesting as thinking about unsolved problems and conducting research.”

Horimbere and Sitaram presented PROPEL to high school students at the Conference for Undergraduate Underrepresented Minorities in Physics (CU²MIP) in January 2021 and encouraged them to apply. During the spring semester, they planned a daily itinerary for the summer program and enlisted physics faculty members—including Gretchen Campbell, Alicia Kollár and Dan Lathrop—to give lectures and lead workshops.

Three high school students were accepted into this summer’s pilot program and paired with mentors based on their research interests. For two months, the students worked daily on their research projects while also attending professional development workshops and lectures and participating in community-building activities. Horimbere, Sitaram and physics graduate students Peter Elgee and Naren Manjunath served as mentors.

Claveria worked with Sitaram and Elgee on atomic physics research, using lasers to cool strontium atoms down to close to 0 K (“absolute zero” temperature), where quantum physics takes over. After flashing the atoms with sequences of laser pulses and taking images of the atom clouds throughout, Sitaram and Elgee measure how the state of the atoms changes. Claveria worked on a coding project to measure those changes.

“Her project is essential to our lab running, because the code that she has written calculates the number of atoms, the temperature and width of the cloud, parameters like that,” Sitaram explained. “This type of analysis is necessary in any experiment in atomic physics.”

The other high school students in the program, Abriana Medina and Kalkidan Michael, studied random walks and saltwater conductivity, respectively.

Medina worked with Manjunath to use Python to compare types of random walks, the process by which randomly moving objects wander away from where they started. The flight path of a cicada or the path traced by a molecule as it travels in a liquid are both examples of random walks that scientists use to model various patterns.

With mentorship from Horimbere, Michael designed and built an experiment to run varying voltages through different levels of turbulence in saltwater to see how much the resistance changed. The goal of this experiment was to provide insight into the potential inefficiencies of a magnetohydrodynamic power plant.

Now that the summer and PROPEL have come to a close, Claveria plans to pursue research opportunities in college and use the information she learned about how to apply for scholarships and other resources to help make college a reality.

“Since I aim to be in a STEM field in the future, I plan to use combinations of what I learned throughout the program in my college career,” Claveria said. “Though I learned basic Python in high school, this program taught me how to utilize it to make graphs and do more complex calculations involving statistics and calculus.”

Teaching high school students and bringing them into research projects required the mentors to take a step back and find ways to make complex physics concepts easier for the students to understand.

“One of my favorite things to do in research is help someone get a result on a project,” Horimbere said. “Together, we get to see exactly how known results come about instead of just plugging variables into an equation that you could find in a reference. Simply doing the calculation yourself is actually quite enlightening. We also get to be surprised by unexpected results that we try to reconcile with existing knowledge.”

PROPEL’s eight-week program culminated in the students presenting their research to the mentors, program coordinators and Donna Hammer, director of education for the Department of Physics.

“What’s great about this pilot for PROPEL is that it’s something these graduate students conceived and put together,” said Peter Shawhan, a physics professor and the chair of the department’s Climate Committee. “It’s a sign of the energy our students have to be proactive about improving diversity and better serving students and the community as a whole by incorporating more people into the scientific effort.”

Looking ahead, Horimbere wants to expand recruiting efforts for this program and enlist faculty members to serve in advisory roles.

“I am convinced that with modest financial support and careful planning, PROPEL would scale very well and have a significant impact on the readiness and diversity of incoming physics and, more generally, STEM students,” Horimbere said.

For Claveria, the PROPEL experience made her less nervous to attend college. From giving her a UMD campus tour to answering her questions about the physics profession to offering tips for scholarships, Sitaram’s mentorship meant everything.

“The best part of this program are the mentors—Ananya felt like a big sister to me. She really inspires me,” Claveria said. “PROPEL gave me more experience with research and made me feel more comfortable with harder concepts in Python, calculus and more.”

Written by Katie Bemb

UMD Leads New $25M NSF Quantum Leap Challenge Institute for Robust Quantum Simulation

Details

Published: Thursday, September 02 2021 13:01

The University of Maryland has been tapped to lead a multi-institutional effort supported by the National Science Foundation (NSF) that is focused on developing quantum simulation devices that can understand, and thereby exploit, the rich behavior of complex quantum systems.

John S. Toll Endowed Lecture in Physics Honors a Culture of Excellence, Curiosity and Collaboration

Details

Published: Wednesday, September 01 2021 00:11

John Toll (1923-2011) knew how to bring talented people together to build something bigger than themselves. 

As chair of the University of Maryland’s Department of Physics and Astronomy from 1953 to 1965, Toll recruited dozens of top-tier scientists to catapult the department onto an international stage. As president of UMD from 1978 to 1988 and founding chancellor of the University System of Maryland from 1988 to 1989, Toll helped grow the system and elevate its reputation. 

In 1990, faculty, staff and administrators of the department established an endowed professorship in his name, and in 2002, the physics building was named after Toll in recognition of his contributions to the university. 

Now, Chuan-Sheng Liu and Jingyi Liu are generously honoring Toll’s enormous legacy by endowing a lecture series in his name. The couple donated $50,000 to establish the John S. Toll Endowed Lecture in Physics, which will bring some of the brightest physicists to UMD’s campus to share their talent and enthusiasm with the community.

Chuan Liu is a professor emeritus of physics who joined UMD in 1974 and served as department chair from 1985 to 1990 and 1993 to 1994. His wife, Jingyi Liu (M.S. ’83, communications; Ph.D. ’91, radio/tv/film), was a cross-cultural communication consultant, educator and TV producer for educational programs, and she served as a contract interpreter for the U.S. Department of State.

The Lius’ gift to the university was followed by a $20,000 contribution from John Toll’s widow, Deborah Toll, who was thrilled to see her husband being honored in this way.

“I’m delighted that the Lius have established this lecture series, and it’s wonderful of them to do it in John’s name,” Toll said. “We now realize how sorely this country needs to improve scientific literacy, and I’m sure if John were alive, he would be doing something about it. If this lecture series can help bring some of the brightest minds to Maryland and get people excited about physics and science, all the better.”

The first John S. Toll Endowed Lecture in Physics was presented by S. James Gates Jr., then-president of the American Physical Society. He was the John S. Toll Professor of Physics from 1998 to 2017. Awarded the President’s National Medal of Science in 2011, Gates served on former President Barack Obama's Council of Advisors on Science and Technology. He is known among scJim Gates and John Toll in 2001.ientists for his work in supersymmetry, supergravity and superstring theory, and is more widely known by the public for his frequent appearances on scientific documentaries. Gates was the Ford Foundation Professor of Physics at Brown University and director of the Brown Theoretical Physics Center before returning to UMD in 2022.

“Gates is a great representative for this first lecture,” Chuan Liu said. “He is a brilliant physicist as well as a very accomplished leader and public speaker. In addition to bringing brilliant people to speak to the community, we want to embody the spirit of collaboration and curiosity that John brought, and I think Gates is a great example of this.”

The Lius stressed that John Toll was dedicated to bringing people together under the umbrella of science and knowledge. It was a core part of John Toll’s personality that they both experienced firsthand throughout the years they knew him.

“We got to know John Toll very well and consider him a good friend,” Chuan Liu said. “I first met him when he came back to Maryland as president of the university, but he was also a physicist, so we had a lot in common and we talked about physics often.”

The Lius were also involved in Toll’s efforts to build relationships with scientists in China. In 1979, soon after the normalization of U.S.-China relations, Chuan Liu and three physicists from Princeton were invited by the Chinese Academy of Sciences to visit the Institute of Plasma Physics in Anhui, China. It would be Chuan Liu’s first return trip to China since his family left the country for Taiwan in 1949, and he was very excited. 

When John Toll learned of the trip, he entrusted Chuan Liu to deliver a letter of invitation on behalf of Maryland Governor Harry Hughes to Wan Li, the governor of China’s Anhui province. Later that year, Wan led a delegation to visit Maryland, and Jingyi Liu served as interpreter for him and his delegation. While in Maryland, she got to know JChuan Sheng Liu and Jingyi Liu ohn Toll and Hughes and they encouraged her to come to UMD for her graduate studies.

The following year, Hughes visited Anhui province. Both John Toll and Chuan Liu were members of Hughes’ delegation. The exchange led to Maryland and Anhui becoming sister-states, which enabled numerous interactions and collaborations.

The Lius agree that part of John Toll’s ability to recruit talent and bring people together was his warmth and enthusiasm, qualities that seemed to come naturally to him. Deborah Toll echoed that sentiment, recalling stories her husband told about his early days as department chair.

“He used to bring some of the best scientists from all over the world to Maryland, and then he would take them to his mother’s house in Chevy Chase,” Toll explained. “She would host them and make meals for them. They had a grand time.”Deborah Toll

It was that kind of personal touch that the Lius remember so fondly. Although their gift reflects a deep appreciation and respect for John Toll as a leader and a scientist, it was his warmth and generosity as a friend that they often refer to when speaking about him. 

“We want to continue the culture of inclusion, excellence and curiosity that John established here,” Chuan Liu said. “He wanted to share the excitement of discovery and to really help spread the spirit of collaboration in science.”  

Perhaps no better example of that spirit is the Department of Physics’ traditional afternoon tea where students, faculty and staff came together daily to discuss science and socialize. John Toll started that tradition when he joined UMD in 1953, and it continued for many decades. 

“He was a person who respected people and tried to bring out their best with his inspirational leadership,” Chuan Liu said. “And he had a truly unselfish spirit that was dedicated to truth and to bigger things than himself. We want this wonderful culture that John Toll started to continue, and in naming this lecture series for John, we want the next generations to remember the older generations and know the history and traditions that were the foundation of the department.” 

Written by Kimbra Cutlip

Follow this link  to a 1989 profile of John S. Toll in the department's newsletter.