Hands-on bricklaying and construction at the International Masonry Institute facility in Bordentown, New Jersey, was the focus of a Wintersession class taught by Sigrid Adriaenssens, professor of civil and environmental engineering.
Princeton's Wintersession marks five years of curiosity-driven learning
Winter’s weather and Princeton’s Wintersession both showed their vigor this year as the campus community braved the cold to come together in warm, welcoming groups for events and classes connecting them as students, faculty and staff.
Wintersession, now in its fifth year, is a two-week program offered between the fall and spring semesters. Students, faculty and staff lead workshops, evening events and trips, and attend as learners to satisfy their intellectual curiosity.
W. Rochelle Calhoun, the University's vice president for campus life, said members of the campus community relish the opportunity to take part in Wintersession — she has led sessions in past years and during Wintersession 2025, including a “Paint Night” and “High Tea with the VP.”
The program “encourages participation and a spirit of community,” she said, noting that participants surveyed after past Wintersessions have reported a strong sense of belonging.
Wintersession 2025 ran from Jan. 13 to 26, including 384 daytime workshops, 74 off-campus trips and 51 evening events. This year’s program — organized by the Office of Campus Engagement — had the most participants thus far, with more than 6,600 undergraduate students, graduate students, postdoctoral scholars, staff and faculty registrants. Fifty-five percent of all undergraduate students and 61% of all graduate students signed up for Wintersession 2025. Nearly 500 Princetonians led one or more Wintersession offerings.
“Now that Wintersession is five years old, we’ve gotten to realize many of our goals,” said Judy Jarvis, executive director for the Office of Campus Engagement. “The permission Princeton University gives the campus to learn and engage just for the sake of learning during Wintersession is a very significant contribution to campus well-being. I’m so proud of what Wintersession is shaping up to be for this campus.”
Below are vignettes from the this year's Wintersession program.
The Princeton Blacksmithing Club led an introductory workshop where participants learned to forge metal projects.
Building Hands-on Knowledge of Masonry
On the first day of Wintersession, participants traveled off campus to the International Masonry Institute (IMI) facility in Bordentown, New Jersey, with Sigrid Adriaenssens, professor of civil and environmental engineering, for a hands-on masonry workshop where they collaborated with craftworkers to lay bricks and construct arches.
Adriaenssens, who engineers sustainable and lightweight structures, had partnered earlier with the architectural firm SOM on a masonry and augmented reality project that won IMI's JBC Masonry Innovation Award Competition last year. Compared to materials like steel and concrete, Adriaenssens said that bricks, especially upcycled ones made from post-consumer material, require significantly less energy to produce and can even be reused after cleaning.
Participants learned the basics of masonry before grabbing their trowels and stacking horizontal layers of bricks. Next, they worked in groups to erect arches over them.
While friendly competition motivated the students to try building their sections the fastest, Adriaenssens said they also had to stack to the same height before everyone could progress to the next level.
“Individually, you are challenged, but also, you're working on something collectively, and actually, that's the whole idea of a brick," Adriaenssens said. “You can put it together with other people in different ways to achieve a form that's bigger than the brick itself.”
After the craftworkers removed the wooden support structures underneath, all the arches remained standing, which Adriaenssens said was a physical testament to their teamwork.
Israel Adeboga, a first-year student from London, said that while he initially considered staying home during the break, “I'm glad that I decided to come two weeks early for Wintersession because there's so much you can do.”
“If I hadn't done this, I doubt there'd be a time where I'd come across masonry,” he said. “It's been a really rewarding experience.”
Adriaenssens said Wintersession classes “where people get to work with their hands” open new vistas for Princeton students who work mostly with their minds.
Masonry “opens the window into a world that maybe otherwise they will just walk past,” she said. “And then they will have much greater appreciation for the craftsmanship, for the skills that go into the artifacts that surround them.”
Learning Reconciliation with Rose Castle
Every fall break, a cohort of undergraduate students visits the Rose Castle Foundation in Cumbria, England, for a weeklong workshop that fosters dialogue across difference. To share those principles with the campus community, the Rev. Theresa Thames, the University's dean of religious life and of the chapel, led a two-day Wintersession in Murray-Dodge Hall with visiting facilitators from Rose Castle.
Thames said the snapshot of the “Rose Castle experience" offers participants the opportunity to incorporate reconciliation skills into their personal and professional lives. This year’s class included staff and graduate students.
“What I most appreciate about the Rose Castle model of reconciliation is that it is not about consensus,” Thames said. “It really is about how do we maintain community, how do we form community, even if we have differences of views or opinions.”
"Even if it's just one thing, one tool, or one aspect that they walk away with, they're able to — a phrase that we use — create rose-shaped spaces across campus,” Thames said. “Coming here and having a bit of it opens the eyes to possibilities around active listening, conflict management, leadership, supervision, important tools and a different way to show up in their work.”
In group conversations and outdoor “walk-and-talks” with a partner, participants came away with new perspectives.
In one exercise, participants partnered with someone they hadn’t known previously and shared a time they experienced conflict. The listener then “echoed” the story back to its teller. This emphasized the importance of active listening skills and hearing other perspectives.
Through Rose Castle, James Packman, a graduate student in psychology, said he learned that “reconciliation is not a business negotiation where you’re trying to win or lose,” but a way of finding common ground even when you disagree strongly.
Mohamed Siam, a Princeton staff member and military veteran who works with student veterans at the Emma Bloomberg Center for Access & Opportunity, said a session where participants were asked to bring photographs that gave them hope was something he might try to incorporate at the center.
“It is something that I and a lot of other Marines did when we were in Afghanistan,” he said. “They had pictures of something that they loved — most of the time, their family members, their girlfriend, their wife — that gave them a motivational boost. Doing this activity today made me think of that, and I was, like, why don't I do that with my students and see if that's something that I could have them do — put a photo in your wallet that's going to motivate you for the hard times.
“I think those little things that I'm being taught here are a complement to how I'm already trying to run the program that I'm a part of,” he said.
Growing Crystals and Minds
In “What Do Hedgehogs Have in Common with Industrial Crystallizers,” participants grew ammonium phosphate “spikes” on toy hedgehogs in an experiment simulating how crystallization works in the lab.
Jean Tom, a professor of the practice in chemical and biological engineering who earned her Ph.D. from Princeton in 1993, led the class in creating the colorful creatures.
A student simulates industrial crystallization in a Wintersession class led by Jean Tom, a professor of the practice in chemical and biological engineering.
"I wanted to do something to show the diversity of what chemical engineering is. For folks unfamiliar with the field, they immediately think the field is just about refineries and converting fossil fuels into chemicals,” Tom said. “Chemical engineering is about using the laws of nature — thermodynamics, fluid dynamics and kinetics — to make molecules to enhance our life.”
Tom joined the department in September 2024 after retiring from a 38-year career in the pharmaceutical industry, most recently at Bristol Myers Squibb, where she used crystallization processes to develop drug compounds. She adapted the Wintersession course from a module created by Gerard Capellades, an assistant professor of chemical engineering at Rowan University, who used it to teach separation processes.
On the first day of the workshop, Tom explained that crystallization is present in everything from glaciers to honey. For the hedgehog experiment, participants dissolved the crystals in hot water and insulated the container to avoid sudden drops in temperature. They then pieced together a premade hedgehog head and a “seed rock” from which the crystals would grow as its "quills," and added their hedgehog to the solution. A week later, they returned to remove them and compare results.
The workshop used crystal hedgehog kits. Participants grew their hedgehogs’ ammonium phosphate “quills” over the course of a week.
William Parson and Jonathan Liu, both prospective mathematics majors in the Class of 2028, won prizes for growing the biggest hedgehogs by weight — a win they attributed to having microwaved the solution on its second day.
"It was so cool to be able to see how even minuscule differences in how we carried out the experiment led to tangible results," Liu said.
Parson said that the experiment let students from across disciplines enjoy chemistry and engineering without taking a traditional class.
“You could get really into the chemistry if you wanted to, but it was also just a fun craft,” he added.
Brooke Shields ’87 on ‘Four Years of Safety’ at Princeton
The University's Office of Community and Regional Affairs partnered with the Princeton Public Library to feature a Wintersession book talk with Brooke Shields in Richardson Auditorium.
Shields, a Class of 1987 alumnus, discussed her third memoir, “Brooke Shields Is Not Allowed to Get Old: Thoughts on Aging as a Woman,” in conversation with Idra Novey, a lecturer in creative writing and the Lewis Center for the Arts.
Actress and model Brooke Shields (right), a Class of 1987 alumnus, talks with Idra Novey (left), a lecturer in creative writing and the Lewis Center for the Arts, during a Jan. 15 book talk in partnership with the Princeton Public Library.
In addition to her time at Princeton, Shields discussed society’s perceptions about gender and age and talked about her newfound confidence as an entrepreneur and author.
Having grown up in the public eye as a model and actress, Shields described her time at the University as "four years of safety,” where she felt protected by her fellow students and gained confidence in herself.
“This is the first place that I felt the freedom to understand my own thoughts,” she said. “My favorite memory is just that this was a place of protection and safety for me when the world was not necessarily prone to wanting to protect me.”
‘Beyond the Resume’ Goes Gold
The fifth annual "Beyond the Resume" keynote featured Olympic and Paralympic athletes Tara Davis-Woodhall and Hunter Woodhall in conversation with Jarvis, who interviewed them in Richardson Auditorium.
Athletes Tara Davis-Woodhall (far left) and Hunter Woodhall (center left), who won gold medals at the 2024 Olympics and Paralympics, respectively, speak with Judy Jarvis (right), executive director for the Office of Campus Engagement, during the “Beyond the Resume” conversation in Richardson Auditorium on Jan. 25.
Davis-Woodhall, an Olympic long jumper, and Woodhall, a Paralympic sprinter, were both gold medal winners at the 2024 Olympics and Paralympics in Paris. After their celebration of each other’s victories went viral on social media, they became known as the “golden couple” and have become sought-after motivational speakers.
When Jarvis asked if they’ve learned any lessons about dealing with setbacks, or rely on certain habits, Davis-Woodhall said she finds it helpful to have an outlet to process emotions. “I’ve learned that journaling and talking to someone and opening up about those thoughts have actually helped me,” she said. “As soon as I get it down on paper, it's out of my head, and I'm like, 'Wow, I feel free.’”
Woodhall recommended “celebrating the little wins” and remembering “that a failure is just an opportunity to learn.”
Jana TerWee, a member of the Class of 2028 and a shot put and hammer thrower on Princeton's track and field team, said she was inspired by Woodhall’s insights about bouncing back from unexpected challenges. “It's exactly what I needed to hear as a student and an athlete.”
And Much More
Wintersession’s other offerings included a Martin Luther King Jr. Day reception and artist talk with Tamara Torres in partnership with the Arts Council of Princeton; a “Get to Know the Garden State” tour of the New Jersey State House with Princeton’s Office of State Affairs; and a disability access training program, run by the AccessAbility Center.
Princeton's Office of Finance and Treasury’s Financial Literacy Program organized an alumni panel featuring University trustee Liz Myers ‘92, global chairman of investment banking at J.P. Morgan; Eric Kaplan ‘90, president of Financial Literacy for All and executive vice president of Operation HOPE; and Paget MacColl ‘99, senior managing director at Blackstone Multi-Asset Investing.
Adam Oberlin, a senior lecturer in German who has led an offering every year of Wintersession, taught his popular "Stay Cool with Icelandic" workshop again in 2025. Oberlin, whose background is in historical linguistics, said that the Wintersession course gives him a platform for sharing this passion with others. He also led "Indo-European for Practical Language Learning.”
“I'm a polyglot. I'm multilingual,” he said. “I thought, what better way to bridge those two sides of my interests with something that I could offer to the community?”
He said it's been rewarding to see students he met through Wintersession later take German with him and to see his German students attend his Icelandic Wintersession class. “I've had a lot of connections that have lasted for a while because of that,” he said.
Maddy Pryor contributed to this story.
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The Wintersession Kick-off Festival included ice sculptures, interactive activities and live performances at the Lewis Center for the Arts Forum.
