Last Saturday, 171 New Haven middle school girls took over Sloane Physics Lab to broaden their scientific horizons and discover the properties of light.

The event, titled “The World of Light,” was organized by Girls’ Science Investigations, a free program for New Haven middle school girls founded in 2007 by Yale physics professor Bonnie Fleming. The goal of the program is to empower young women by showing them that they can be successful in the realm of science. The students spent five hours Saturday experimenting with and creating projectors, periscopes, optical fiber flowers and virtual reality goggles.

Fleming — who co-directs GSI with fellow physics professor Rona Ramos — explained that she first founded a similar program as the outreach component of her Lederman Fellowship at Fermilab in Illinois.

“There’s a break in the pipeline for girls after middle school. Before middle school, girls do better in science than they do afterwards, and we don’t know why,” Fleming said.

Fleming added that when she joined the Yale faculty, she knew New Haven could benefit from a similar program.

Stefan Krastanov GRD ’19, the program’s coordinator this year, said that the program counteracts the sharp drop in girls’ interest in science after middle school.

“There are mostly cultural reasons why women’s involvement declines,” Krastanov said. “If you don’t have that type of mentoring around you … [you] develop a stereotype, which can hurt you even if you don’t believe in that stereotype because others might.”

Fleming added that in addition to the program encouraging participants to engage with scientific fields, it teaches students about physics in greater depth.

Upon arrival, the girls were split into groups of 30 students, with about seven volunteers working with the groups. After a short introduction and demonstration, the students experimented with mirrors and prisms, wrote encoded notes in invisible ink, decorated their own periscopes and built fiber optic flowers, projectors and virtual reality goggles.

“The VR goggles — that was my favorite,” Fleming said. “We’ve done ‘The World of Light’ before, but we developed it further this year by adding the construction of these goggles, to keep it current, she said. “The goggles were made of a cardboard piece with strong lenses, attached to a smartphone, so the girls could see images in 3D.”

Durga Thakral ’12 GRD ’20, who has been working with GSI since 2009, said what inspires her most about the program is how the creativity and curiosity of the participants reflect her own thought processes while in a lab.

“In my group, one girl was trying to get a picture of the puppy she had drawn to show up through her projector lens,” Thakral said. “She systematically experimented to find the optimal position of the light source. That’s what we do in the lab. You could do a thousand calculations, but sometimes you just can’t predict how an experiment will turn out until you try it.”

Thakral was one of about 50 total volunteers at “The World of Light” event. The volunteers included graduate and undergraduate students, postdoctoral researchers and assistant professors, as well as high school students who completed GSI themselves.

In 2014, the Yale Physics Department, which funded the program, was struggling to keep up with the community’s growing interest in GSI, resulting in a year-long hiatus. However, since then the Yale Office of New Haven and State Affairs has taken on a significant role in managing the program.

GSI is now part of Yale’s Pathways to Science program, an initiative that aims to increase science outreach in New Haven, and is primarily funded by the provost and the Michele Dufault Fund, which honors a Yale student who died in a 2011 lab accident.

Maria Parente GRD ’07, the YPS coordinator for community programs in science, said that by handling the logistical pieces, Pathways to Science takes some of the load off Fleming, Ramos and the rest of the team, enabling them to concentrate on the content of the program.

The GSI curricula is comprised of three full years of material, which the program repeats and modifies on a three-year cycle. It has become so popular that other institutions have requested the curricula so they can host similar events, Fleming said.

The next GSI event, “The World of Sound,” will take place on Nov. 12.