"Let the challenge begin!" announces Science teacher Melissa Courtemanche to the students in Environmental Studies, a new interdisciplinary course she co-teaches with History and Social Sciences teacher Matt Turnbull. Eagerly taking up the gauntlet, three-person groups huddle at lab tables, discussing the ideas they had been brainstorming online the night before.
"I don't think we should do any of the balloon ideas," says Ben Morris '18.
"Do we have access to a tape measure?" asks Isabella Kennedy '18.
Having studied fossil fuels and nonrenewable energy, the students are now shifting their focus with this lab project to renewable energy, building on their earlier study of food and agriculture.
In a pre-lab class, Courtemanche explained the chemistry behind biofuel production, in which living organisms react with sugar and produce fuel. In this case, the students will combine glucose with a yeast-and-water solution; the resulting fermentation will produce liquid ethanol, a biofuel, and some carbon dioxide. Armed with those assumptions and a limited array of materials, they are out to design a fermentation chamber, an apparatus that will contain the reaction and allow them to measure the amount of gas produced. Then, they can calculate a rate of reaction, which, along with the cost and number of materials, will help the class consider the strengths and weaknesses of each design.
"How's it going over here?" Courtemanche asks a group that has come up with two design ideas. "Ooh, I like it. You have a variety of materials here."
"For the first one, we're going to put the yeast solution and sugar into a calibrated syringe and cap it, so that's a closed system," explains Jossy Wang '18. "Then the gas produced should, theoretically, push the plunger out, and then we can measure the change in volume in there."
"For the next one, we'll put this plastic bag with the yeast and sugar in it into a centrifuge tube filled with water," says Ben.
"Then we can tell how much water is displaced by how much the bag extends," adds Olivia Maduro '18. "The change in volume is the amount of carbon dioxide released."
"We'll need to seal the bag," says Ben. "Hmm... I don't know how we're going to seal it off."
"We could use string," suggests Jossy.
"Be sure to think more about how to seal the bag," says Courtemanche, "but I love it!"
"Science! Yeah!" Jossy exclaims.
By staging a fermentation process, students can "actually see how biofuels are made," says Courtemanche. "It makes the science come alive for them, and they can insert this knowledge into the larger conversation of alternative and renewable energy sources."
The collaborative nature of the work also excites Jossy. "It's a lot of fun, and you get a wide range of ideas from everybody," she says. "It's a really good way to learn."
Ben appreciates the problem-solving skills they have to employ. "I like having to figure out how to design the apparatus and figure the rate of reaction by ourselves because it leads to valuable discussions," he says. "My dad and I make a lot of bread, so it's also interesting to use yeast in a scientific way, other than to raise my bread."
Another group has been debating how much of the allotted two packets of sugar they should add to their yeast solution in a centrifuge tube. Thinking aloud, Maggie Foot '18 offers, "If you have a set amount of yeast, will the yeast be able to break down all the sugar?"
"I think that if you have enough sugar," says Owen Hakim '18, "then you'll cap out the rate of the reaction."
"Exactly," says Maggie.
"So, after some point, it doesn't matter, but I'm not sure what that point is," says Owen.
"Then we should put all the sugar in," says Isaac Glotzer Martin '18. "It wouldn't hurt."
Owen counters, "I mean, it might."
"I think the reaction would just stop once the yeast uses the maximum amount of sugar," says Maggie.
Once the two packets of sugar go into the test tube, the students cover it with a red balloon, which should expand with the production of CO2. They plan to measure the circumference of the balloon at one-minute intervals to figure the rate of reaction. "It's sort of mass by volume," says Owen.
A few tables away, Courtemanche, a bright-eyed dynamo, lets out a whoop. "We've got action! What do you see there? Tons, tons, tons! What is it?"
Isabella leans in for a look. "Bubbles!"
"What does that mean?"
Isabella grins. "There's gas!"
"Yeah!" says Courtemanche, returning the smile.
Courtemanche's infectious energy does not go unappreciated. Jossy notes, "She's really, really passionate about environmental studies. She makes it engaging, and the way she interacts with us gets everyone really excited."
For her part, Courtemanche would like students to see that she's "someone who's willing to learn alongside them in a lot of ways, someone who wants to know how they're thinking and feeling about the material." Especially given the interdisciplinary nature of the course, Courtemanche hopes students perceive its relevance to their lives. "They are engaging with the world around them," she says, "by getting their hands dirty in the soil at BB&N or putting their hands in the Charles River—and also by interacting with the news and contemporary issues, set against a historical perspective."
That's where Matt Turnbull comes in. "I've enjoyed expanding the students' understanding of what's come before them," he says, "giving them a much broader repertoire of knowledge about how ideas have changed over time, how past events have influenced where we are today."
In developing this interdisciplinary course—using as a foundation the Environmental Science course Courtemanche taught here for seven years—she and Turnbull have adopted a systems thinking approach, which eschews narrow classification of subjects for interconnectedness. As Jossy explains it, "We get a lot of different perspectives on all the subjects we've covered. Especially with the water and food units—we've tied in a lot of history, politics, and social justice. Before this, I wouldn't necessarily have thought about how toxic waste can affect certain people just because of their income or race," she says. "I would recommend this class to everyone because they need to know this type of thinking, this knowledge. This class gives a really good global understanding of issues."
Jenna Selden '18, who labels herself as more of a "humanities person," says that within the first three weeks, she knew that she wanted to pursue an Environmental Studies major in college. "I'm fascinated by it," she says. "Ethics, philosophy, history—if separated, there's no way to think of a comprehensive solution to anything. Learning the science and history together is the only way to make effective change. You have to understand the whole picture."
Well aware that her students might find dispiriting the many environmental problems the world faces today, Courtemanche aims to counter the "gloom and doom," as she puts it, by "trying to spark their thinking about solutions, their optimism, their innovation."
Meanwhile, Liv has managed to seal her group's small plastic bag holding the yeast and sugar by tying a sailor's knot. Courtemanche applauds and says, laughing, "Sailor's knot! Who knew that was going to be a skill set for the team!" She goes on to commend Zach Cyr '19 for his creative thinking; he placed his group's centrifuge tube-and-balloon design in the heat of both the radiator and the sun to speed up the reaction.
Having decided that no harm could come from allowing the reactions to continue beyond class time, Courtemanche and the students pick up the process the next day, when students can run another trial, based on what their first experiments taught them, and work on calculating their rates of reaction.
"Because you all have different apparatuses, how are we going to compare their effectiveness?" Courtemanche asks. "Not how we actually do so—but what do we need?"
Several voices respond, "A common unit."
"Right. What do we have to report? Volume of yeast. What else?"
"Amount of sugar."
"Yes," Courtemanche continues, "and then rate of reaction, which we're indirectly measuring by the amount of CO2 produced. We can relay all that information and then as a group decide what we think the best design is, but we need the language to have the conversation."
Assessing their two designs, Ben notes, "Our syringe's plunger shot out because there was so much pressure."
"I think that's the one limitation," Jossy says, "because they're rigid containers. They're not like the balloons—they can run for only a certain amount of time." She points to the plastic bag submerged in the centrifuge tube. "If that one had worked better...."
"It would have overflowed," says Ben.
"But if we had bigger vessels," Jossy reasons, "then it could run longer, but we were limited in supplies."
The students realize that their fixed containers made measurements much easier to take than a balloon's.
"Plus, the plastic tubing one cost only 52 cents," says Ben.
Part of the lab assignment asks students to consider how they would "upscale" to mass biofuel production. Jossy reflects realistically, "It would be really hard to do this on a large scale. Trying to control this reaction and make sure it's safe and efficient with sustainable materials in big power plants—it'd be difficult."
Jenna approaches Courtemanche with her "upscaling" calculations. "Do you want to look at our math and tell us that it's wrong?"
"Nice work," says Courtemanche. "You did it! See? Now, you master-teach your group."
"I feel so cool!"
"You should! You've got to lead with confidence. How about, 'Can you look at this and tell me that I'm right?'"
Jenna laughs and nods.
Extrapolating from their small lab-sized example, the students wrangle with the pros and cons of biofuels. "One of the biggest complaints about biofuels in general is the land-mass use," Courtemanche explains, referring to land needed for growing the requisite corn or sugar cane, for example. "They're even thinking about using the ocean surface to make biofuels out of algae."
Drawing on her knowledge from their unit on fossil fuels, Maggie says, "I know it's not exactly the same, but the land that's used for coal mines and oil fields, that's a pretty significant amount of space, too, right?"
"That's a good point," says Courtemanche.
"I know it's harder with biofuels because you need the right kind of growing conditions and soil," Maggie continues.
"We talked about how mining companies are required by law to remediate the land, right?—that is, to put back the topsoil and clean up after themselves," Courtemanche says. "Could you turn that, then, into fertile ground? Somebody working on soil science would find that an interesting question."
As Courtemanche thinks about the students engaging with the course material, she says, "They're really impressive. Pretty much on a daily basis, I'm like, wow—these students are smart, informed; they're eating this up, grappling with it."
She hopes that her students feel "curious, emboldened, safe to make opinions and to change their minds." She would like them to see, she says, "that we care about these issues. We want to impart our sense of responsibility and stewardship onto the students. What they do with that is totally up to them, but I want to deliver the message that these issues affect us every day."
Armando Hazaveh '18 says, "The class's discussions are lively and urgent. We all enjoy picking our way through these issues, and we are all inspired not only to speak but to act."
"It's been really fun," Turnbull says, "to see them come to class excited to keep talking about those things—and not just because it was their homework but because they're really staking out their positions on important issues."
"This course has definitely shaped my path," Jossy says. "I've gotten so much from it." She became interested in taking the course after Turnbull, her junior-year U.S. History teacher, suggested she might augment her penchant for science by writing her research paper about environmental justice. "I found it really interesting," Jossy notes, "to look at how some environmental issues disproportionately impact people of color and minorities. I'd like to study further the social justice aspects of these issues."
Courtemanche says, "They're thinking about who they want to become; figuring out what's important to them is part of their identity building. I think they're ready in their education to really fuse what they're learning in their classes and what they're seeing in the world." She looks across the lab room at the next generation of problem-solvers and innovators in the making. "It's kind of cool to be along for that ride and to offer them a course that models that in an intentional and structured way."
Written by Sharon Krauss, Upper School English Department