In fairness, Michael Mazza, a first-year Caltech graduate student, did warn the fourth-grade class at Cleveland Elementary School that science "can be messy."
Conducting an experiment to extract DNA from plant cells, the kids enthusiastically squished strawberries in plastic baggies filled with a detergent-alcohol solution—creating a sticky red mixture that many children soon dribbled on themselves and their tables. But by the end of the lesson, each student was able to show off a vial of distilled DNA they had created and, in spite of the mess—or maybe a little bit because of it—they were thrilled to be able to do real science themselves.
"I love their enthusiasm," says Mazza, who studies chemistry and chemical engineering. "I love that so many of the students are excited for science every Wednesday."
Mazza is one of several Caltech grad students and postdocs who volunteer at Cleveland Elementary as part of a program called Science Wednesdays, which provides weekly hands-on science lessons for all the grades at the K-5 Pasadena school.
The program began in January when the school—a science, technology, engineering, arts, and math (STEAM) magnet campus—was unable to fill a position for a half-time STEAM coach. School principal Debra Lucas reached out to Caltech for help. The Institute's Center for Teaching, Learning, & Outreach (CTLO) was able to partner with the school and its teachers to provide specialized instruction and demonstrations.
Lucas says the program has been a success not only because it allows the children to learn science from actual scientists, but also because the scientists "talk about their personal journey and what makes them curious and want to learn more. That brings relevance to our students' lives."
Fourth-grade teacher Beth Burleson Mortilla, whose class conducted the DNA extraction experiment, says she agrees and lauds the Caltech instructors as great role models who are "contagiously enthusiastic about science."
She adds, "They are so patient with my students. If an experiment doesn't work the way they'd planned, they take time to explain to the kids that this happens in science and discuss what they might do differently next time. The program is extremely useful on many levels. It's great science—often science that I don't know, so I'm learning right along with the kids."
Mitch Aiken, CTLO's associate director for educational outreach, says that the Cleveland students are not the sole beneficiaries of the program. "Our students are getting deep experience with preparing and teaching lessons, developing classroom management techniques, and gaining confidence in their own skills."
Aiken says that outreach initiatives like Science Wednesdays "are critical to providing opportunities for our scholars to share their work with teachers and younger students, helping Caltech contribute to a more diverse STEM pipeline. This benefits Caltech, our future students, and the larger community of K-12 learners. By helping our students and researchers share their passion for science with these young people, we are supporting the next two generations of scientists."
A less messy experiment was conducted by Cecelia Sanders, a first-year graduate student in geological and planetary sciences. She coached a Cleveland second-grade class through a different genetics exercise, using envelopes filled with colored snippets of paper that represented dog genes coding for ear shape, tail shape, eye color, coat color, and kind of hair. Choosing one gene from each envelope, students created a paper chain of "DNA" to represent their dog's characteristics and then drew a picture of their canine.
Sanders appreciates the opportunity to teach in the program for several reasons. "I think it actually makes me a better scientist and thinker," she says. "You don't really understand something until you can explain it to a 6-year-old and get them to retain it."
She adds, "Working with kids—any kind of educational outreach—connects science to humanity. Everybody is born with a sense of wonder and curiosity, and I don't think there's anything more important in the world than nurturing that."