Physics undergraduates named 2022 Hilldale Fellows

Three UW–Madison undergraduate physics majors have been named 2022 Hilldale Fellows, in addition to one engineering physics major who is conducting their research in the Physics Department.

The Hilldale Undergraduate/Faculty Research Fellowship provides research training and support to undergraduates at UW–Madison. Students have the opportunity to undertake their own research project in collaboration with UW–Madison faculty or research/instructional academic staff. Approximately 97 – 100 Hilldale awards are available each year.

The students are:

  • Astronomy-Physics and Physics major Elyse Incha, in Susanna Widicus Weaver’s group (Chemistry)
  • Mathematics and Physics major Haoyi Jia, in Sridhara Dasu’s group (Physics)
  • Music and Physics major Daniel Laws, in Mary Halloran’s group (Integrative Biology)
  • Engineering physics major Nico Ranabhat, in Shimon Kolkowitz’s group (Physics)

Lucy Steffes awarded 2022 Goldwater Scholarship

This story was adapted from one first published by University Communications

Four University of Wisconsin–Madison students have been named winners of 2022 Barry Goldwater Scholarships, one of the most prestigious awards in the U.S. for undergraduates studying the sciences.

The UW–Madison winners are sophomore Lucy Steffes and juniors Sarah Fahlberg, Elias Kemna and Samuel Neuman.

Each university in the country may nominate up to four undergraduates for the annual award. To have all four candidates win is remarkable, says Julie Stubbs, director of UW’s Office of Undergraduate Academic Awards.

Lucy Steffes is a sophomore from Milwaukee, double-majoring in astronomy-physics and physics with a certificate in German. Her freshman year, Steffes began working with astronomy professor Snezana Stanimirovic on the ALMA-SPONGE project, for which she co-authored two papers recently published in the Astrophysical Journal. The project looks at molecular formation in the interstellar medium to describe potentially star-forming regions. At the end of her freshman year, Steffes earned a Hilldale Undergraduate Research Fellowship to calculate the upper limits of molecular detections in the Magellanic Stream. She spent last summer working at the Green Bank Observatory in West Virginia examining the chemical composition and evolution of two globules in the Helix Nebula. This summer, she will be returning to the observatory to examine neutral atomic carbon across the Helix Nebula. She plans to pursue a Ph.D. in astrophysics.

Physics & math senior Gage Siebert awarded NSF GRFP

profile photo of gage siebert
Gage Siebert

Congratulations to Gage Siebert for being awarded a National Science Foundation Graduate Research Fellowship! Gage is a senior math and physics major who has been conducting research in radio astronomy and cosmology. He is working on the optics of NASA’s EXCLAIM mission and constructing a periodicity search using the Tianlai Radio Array. Gage is also a 2021 Hilldale Fellow and Goldwater Scholar, and has won the department’s Hagengruber Scholarship, Liebenberg Family Scholarship, and Henry & Eleanor Firminhac Scholarship. He plans to attend graduate school but has not decided where yet.

Peter Timbie, Gage’s research advisor, says:

Congratulations Gage on winning one of these exceedingly rare awards! We’re really proud of you,Best of luck with you proposal to search for periodic signals in cosmological survey data and your plans for graduate school.

21 UW–Madison students in total received the fellowship, a highly sought and competitive award. The Graduate Research Fellowship Program supports high-potential scientists and engineers in the early stages of their careers. Each year, more than 12,000 applicants compete for 2,000 fellowship awards.

Awardees from UW–Madison, including both undergraduate and graduate students, represent a variety of specializations across science, engineering, and technology. Another 23 UW–Madison students were recognized with honorable mentions.

The program provides awardees with three years of financial support consisting of a $34,000 annual stipend and a $12,000 education allowance. UW–Madison contributes toward fringe benefits.

Coral skeleton formation rate determines resilience to acidifying oceans

A new University of Wisconsin–Madison study has implications for predicting coral reef survival and developing mitigation strategies against having their bony skeletons weakened by ocean acidification.

Though coral reefs make up less than one percent of the ocean floor, these ecosystems are among the most biodiverse on the planet — with over a million species estimated to be associated with reefs.

The coral species that make up these reefs are known to be differently sensitive or resilient to ocean acidification — the result of increasing atmospheric carbon dioxide levels. But scientists are not sure why.

In the study, researchers show that the crystallization rate of coral skeletons differs across species and is correlated with their resilience to acidification.

A woman holding two coral species stands in front of a body of water
“Finding solutions that are science-based is a priority,” says physics professor Pupa Gilbert, shown here with samples of scleractinian coral along the Lake Monona shoreline in Madison. | Photo: Jeff Miller

“Many agencies keep putting out reports in which they say, ‘Yes, coral reefs are threatened,’ with no idea what to do,” says Pupa Gilbert, a physics professor at UW–Madison and senior author of the study that was published Jan. 17 in the Journal of the American Chemical Society. “Finding solutions that are science-based is a priority, and having a quantitative idea of exactly what’s happening with climate change to coral reefs and skeletons is really important.”

Reef-forming corals are marine animals that produce a hard skeleton made up of the mostly insoluble crystalline material aragonite. Aragonite forms when precursors made up of a more soluble form, amorphous calcium carbonate, are deposited onto the growing skeleton and then crystallize.

The team studied three genera of coral and took an in-depth look at the components of their growing skeletons. They used a technique that Gilbert pioneered called PEEM spectromicroscopy, which detects the different forms of calcium carbonate with the greatest sensitivity to date.

When they used these spectromicroscopy images to compare the thickness of amorphous precursors to the crystalline form, they found that Acropora, which is more sensitive to acidification, had a much thicker band of amorphous calcium carbonate than Stylophora, which is less sensitive.

A third genus of unknown sensitivity, Turbinaria, had an even thinner amorphous precursor layer than Stylophora, suggesting it should be the most resilient of the three to ocean acidification.

two bright colored images assign a color to the form of calcium present in coral skeletons. On the left there is a thicker band of non-blue (blue is crystalline aragonite) compared to the image on the right where there is almost all blue, indicating the skeleton on the right crystallizes to aragonite more quickly
Coral skeletons were studied with PEEM spectromicroscopy, which identifies the calcium spectrum associated with each imaging pixel, then renders it in false color depending on the form of calcium. Blue is aragonite, the insoluble, crystalline form of calcium carbonate; the other colors represent one of the two amorphous precursor forms, a mix of the two, or a mix of aragonite and precursor form. Acropora spp. (left), has more non-blue pixels compared to Turbinaria spp. (right), indicating that Acropora has more of the soluble, non-crystalline form in its growing skeleton. | Pupa Gilbert and team in JACS

The thicker the band of uncrystallized minerals, the slower the crystallization process.

“If the surface of the coral skeleton, where all this amorphous calcium carbonate is being deposited by the living animal, crystallizes quickly, then that particular species is resilient to ocean acidification; if it crystallizes slowly, then it’s vulnerable,” Gilbert says. “For once, it’s a really simple mechanism.”

The mechanism may have worked out to be simple, but the data analysis required to process and interpret the PEEM images is anything but. Each pixel of imaging data acquired has a calcium spectrum that needs to be analyzed, which results in millions of data points. Processing the data includes many decision-making points, plus massive computing power.

The team has tried to automate the analysis or use machine-learning techniques, but those methods have not worked out. Instead, Gilbert has found that humans making decisions are the best data processors.

Gilbert did not want to base conclusions off the decision-making of just one or two people. So she hired a group of UW–Madison undergraduates, most of whom came from the Mercile J. Lee Scholars Program, which works to attract and retain talented students from underrepresented groups. This team provided a large and diverse group of decision makers.

a zoom screen showing several of the people who conducted the study
Gilbert and her research team met several times a week via Zoom, where students were assigned the same dataset to process in parallel and discuss at their next meeting. The Cnidarians — named after the phylum to which corals belong — include current and former UW–Madison undergraduates: Celeo Matute Diaz, Jorge Rivera Colon, Asiya Ahmed, Virginia Quach, Gabi Barreiro Pujol, Isabelle LeCloux, Sydney Davison, Connor Klaus, Jaden Sengkhamee, Evan Walch and Benjamin Fordyce; and graduate students Cayla Stifler, and Connor Schmidt. Schmidt was also the lead author of the study. | Provided by Pupa Gilbert

Dubbed the Cnidarians — from the phylum to which corals, anemones and jellyfish belong — this group of students became integral members of the team. They met several times a week via Zoom, when Gilbert would assign multiple students the same dataset to process in parallel and discuss at their next meeting.

“If multiple people come up with precisely the same solution even though they make different decisions, that means our analysis is robust and reliable,” Gilbert says. “The Cnidarians’ contributions were so useful that 13 of them are co-authors on this study.”


Several physics majors awarded Hilldale Fellowships

Six UW–Madison undergraduate physics or AMEP majors have been named 2021 Hilldale Fellows, in addition to one computer science major who is conducting their research in the Physics Department.

The Hilldale Undergraduate/Faculty Research Fellowship provides research training and support to undergraduates at UW–Madison. Students have the opportunity to undertake their own research project in collaboration with UW–Madison faculty or research/instructional academic staff. Approximately 97 – 100 Hilldale awards are available each year.

Three students are conducting research in the Department of Physics, including:

  • Mathematics and Physics major Gage Siebert, in Prof. Peter Timbie’s group
  • Physics major Haley Stueber, in Prof. Dan McCammon’s group
  • Computer Sciences major Nikhilesh Venkatasubramanian, in Prof. Tulika Bose’s group

The physics or AMEP majors who have been named Hilldale Fellows and are conducting research outside the department are:

  • Mathematics and Physics major Sam Christianson, with Saverio Spagnolie (Mathematics)
  • Astronomy – Physics, Biochemistry, Chemistry, Mathematics, Molecular & Cell Biology, Neurobiology, Physics, Psychology, and Zoology major Renxi Li, with Catherine Gallagher (Neurology)
  • AMEP major Shenwei Yin, with Joseph Andrews (Mechanical Engineering)
  • Computer Sciences and Physics major Heqiao (Wonder) Zhu, with Kevin Eliceiri (LOCI)

Gage Siebert named 2021 Goldwater Scholar

profile photo of gage siebert
Gage Siebert 

Three University of Wisconsin–Madison students, including junior Physics and Math major Gage Siebert, have been named 2021 winners of the Barry Goldwater Scholarship, considered the country’s preeminent undergraduate scholarship in the natural sciences, mathematics and engineering.

As a freshman, Siebert studied the origins of life in Professor David Baum’s lab at the Wisconsin Institute for Discovery. Siebert then interned at the Arecibo Observatory in Puerto Rico, studying the radio emission from several of the millisecond pulsars used in the search for gravitational waves. He later presented this work at a meeting of the American Astronomical Society. For the past two years, Siebert has worked in Professor Peter Timbie’s observational cosmology lab on the Tianlai Array, a radio astronomy experiment built to map hydrogen. He plans to pursue a Ph.D. in physics.

More than 1,250 students were nominated this year from 438 academic institutions; 410 were named Goldwater Scholars. The scholarship program honors the late Sen. Barry Goldwater and was designed to develop highly qualified scientists, engineers and mathematicians. The scholarships were first awarded in 1989. Each scholar will receive up to $7,500 for their senior year of undergraduate study.

This post was adapted from this post originally published by University Communications


Three undergraduate students awarded Hilldale Fellowships

Congratulations to the three physics undergraduate research students who earned Hilldale fellowships for 2020-21! They are:

  • Owen Rafferty, in Robert McDermott’s group
  • Yanlin Wu, in Peter Timbie’s group
  • Yan Qian, in Sau Lan Wu’s group

The Hilldale Undergraduate/Faculty Research Fellowship provides research training and support to undergraduates at UW–Madison. Students have the opportunity to undertake their own research project in collaboration with UW–Madison faculty or research/instructional academic staff. Approximately 97 – 100 Hilldale awards are available each year.