When you picture a mathematician, whom do you see?
Maybe it is Albert Einstein or Pythagoras (of the famed triangle). Or Euclid, the ancient Greek known as the father of geometry. Or Isaac Newton, the Enlightenment-era British scientist known for laws of motion and observations about falling apples.
The names Yitang Zhang, Chelsea Walton and Eugenia Cheng are likely left out. But they shouldn’t be.
Zhang, Walton and other modern-day mathematicians are the subject of Tracy Gillespie’s block print poster exhibit “Mathematicians Made Visible,” which is on display at Long River Gallery in downtown White River Junction. A reception will be held April 1 during First Friday.
Gillespie, who teaches middle school math at The Sharon Academy, came up with the idea when she was researching ideas for creating a Pi Day poster for her students.
“I noticed all I was finding were stories about essentially white men and it hit me, ‘Really I’m going to make another poster for a math classroom with these men who have white hair and are dead,’ ” Gillespie said. “I started getting frustrated.”
Mathematicians are a diverse group, but that diversity isn’t always represented in educational materials. Gillespie decided to create a portrait series of contemporary mathematicians who come from a variety of backgrounds, including those who are women, people of color or LGBTQ.
She’s created nine portraits so far and her goal is to make three more.
“That might help a more diverse group of students imagine themselves as mathematicians if they can see themselves reflected in a group of people we call mathematicians,” Gillespie said. “They might think, ‘Oh that might be possible for me.’ ”
Zhang was a calculus professor at the University of New Hampshire when he made an important discovery about a decade ago regarding prime pairs — what are two prime numbers that are near each other.
“He proved that there are an infinite number of prime pairs whose difference is less than 70 million,” Gillespie said. “It’s like a start. It’s a start toward proving there are an infinite number of prime pairs with smaller differences.”
Another mathematician is Walton, a professor at Rice University who in 2018 became the first woman awarded the André Lichnerowicz Prize in Poisson geometry. There’s also Cheng, a British mathematician who is also a classical pianist, which appeals to Gillespie.
“There’s not just one way to be a mathematician,” Gillespie said. “Also there’s not just one way to look if you’re a mathematician. There’s a lot of diversity there that we don’t typically see.”
Another source of inspiration was Desmos, a graphing calculator computer program that Gillespie uses with her students. If she wants to show a student’s answer, but not their identity, to the class, she can turn on a feature that replaces their names with those of mathematicians.
“They’ve made a deliberate effort to come up with a list of mathematicians from a culturally diverse population that isn’t usually talked about in math classrooms,” Gillespie said. “The fact that I couldn’t really imagine what these people look like because I didn’t really know who they were ... really inspired me to do some research and start making some portraits.”
Gillespie has taught math for around 25 years. When she entered college, she had her mind set on being an English teacher, but a college counselor told her to reconsider because of her talents in math.
“He actually used the words ‘because we need more women math teachers and I said, ‘That’s right we do,’ ” Gillespie recalled, adding that all through middle school, high school and college she had only one female math teacher. When she joined her college’s math program she was one of two women and she ended up switching to study art education. After college, she started teaching in a GED program where she realized how much she enjoyed teaching math.
“I feel like I can do something to make this make sense to people,” Gillespie said. “When I thought about how hard it was for me, I think it must be much harder for Black women, or transgender women.”
Gillespie hopes the exhibit will encourage people to think more about mathematicians and the contributions people from all backgrounds have made to the field.
“I want people to come away thinking ‘That could be me.’ I could be a mathematician,” Gillespie said.
Editor’s note: Long River Gallery, located at 49 S. Main St. in White River Junction, is open from 11 a.m. to 5 p.m. Wednesday-Saturday.
Liz Sauchelli can be reached at esauchelli@vnews.com or 603-727-3221.