When Carolin Gnebner decided to pursue research in physics, she assumed she would eventually spend her days working in a lab, alone. But during high school, she learned that, on the contrary, science is teamwork.
She wanted to make sure the other students knew. “There are so many good people with great ideas working together,” she says. “I saw all the colors of science and wanted to show young students that it is much more than just measuring something. It’s collaboration and it’s fun.”
To spread this message, Gnebner, who is now the scientific coordinator of astroparticle physics outreach and education projects at Deutsches Elektronen-Synchrotron DESY in Germany, created International Cosmic Day.
Every November, high school students, teachers and scientists gather to talk about cosmic rays. Cosmic rays are high-energy particles from space, such as muons and neutrinos, that rain down relentlessly on Earth.
At ICD, students work as astroparticle scientists, who detect cosmic rays to learn more about their celestial origins. Participating classes work together using real detectors. They then present their results to their global peers. “The main thing is to work like a scientist,” says Gnebner: “Make a measurement, let others know about your findings and discuss these results.”
Gnebner summarizes the results from each group in a booklet similar to the actual conference proceedings. It has done so since the inaugural ICD in 2012.
Under one sky
In the early years, each group would perform the same type of muon-detection experiment and post their findings on a website. Today, students can conduct any kind of cosmic ray-related experiment they want, and DESY graduate students coordinate the ICD through a series of video calls.
Lea Preece, a PhD student at the University of Hamburg, has been helping Gnebner organize the ICD for the past three years. She says she was anxious to receive her first video phone call. “But my overall experience is that students are always fascinated,” she says. “It was such a beautiful experience to see that everyone was excited to meet each other.”
Most groups collect their data the day before the ICD, but others may receive data for weeks before. One year, a group from the island of La Réunion collected data for half a year by placing a detector on a ship to measure how latitude affects the muon flow.
Classes borrow their detectors from local institutes and organizations, such as the QuarkNet Collaboration, a program that partners high school science teachers with particle physicists.
But students do not need a partner institution to participate. Students without access to detectors can still analyze real muon data using a website developed by DESY, Cosmic@Web— another one of Gnebner’s ideas.
Guest scientists from around the world join video calls to share current astroparticle physics research, and students can participate in a “cosmic selfie,” a cosmic particle drawing contest, and online quizzes.
More students are involved in ICD every year. In 2012, 500 students from eight countries participated. Last year several thousand students from 19 countries participated. “Even though the students look different and have different detectors, when they show their data, they see that they are measuring similar things,” says Gnebner. “I really like this.”
In 2022, ICD celebrated its 10th anniversary by producing a video featuring past participants, some of whom have gone on to become astroparticle physicists.
“Over the years, you see how students grow and they find their way into science or something,” says Gnebner, who stays in touch with several participants. “You can make an impact with this one day. That is why it is so important that we do the ICD every year.”
Inspiring the next generation of scientists
Although DESY provides the framework and teaching materials for ICD, it is up to participating teachers and students to decide how their International Cosmic Day will take place.
In 2023, Dylan Guilford, then a junior at Winamac Community High School in Indiana, spent a week measuring how temperature and pressure affected the flow rate of muons in a detector. He says he was surprised at how much the experience affected him. “I thought [ICD] it was just another boring thing we had to sit through in class, but it turned out to be pretty fun.
“It definitely changed my perspective on how research is done and how influential we as students can be. Showing that I could produce data really motivated me to get more involved in particle physics.”
Although Guilford says at first he thought the introduction was difficult, he soon came to appreciate ICD’s international reach. “I didn’t think I’d ever meet people from Japan or other countries, so it was a great experience to talk to them about our data.”
This year, Guilford is excited to participate in ICD for the second time.
His physics and math teacher, Jeremey Wegner, has been participating with his classes since 2012. Wegner says his favorite part is when ICD gets students excited about physics.
“I appreciate the work that Carolin and everyone at DESY does to coordinate all these schools around the world,” he says. “For a small school like ours to be able to participate is a great experience for our students to see that physics is about collaboration and community; it’s not just an old guy in a room just trying to answer questions.”
The 13th ICD will be held on November 26. Registration closes two weeks before the event. Interested teachers and students can visit the ICDs website to learn more, sign up and get ideas for experiments and other activities.
“I would definitely say just go and try it,” Guilford says. “Once you learn what cosmic rays are and how much of an impact they have on our daily lives, I think it can be life-changing. ICD was super fun and helped me decide what I want to do with my life.”