Professor Takematsu researches the science of sunlight
May 14, 2021
Assistant Professor of Chemistry and Biochemistry Kana Takematsu follows the sunlight and wants Bowdoin students to do the same.
“I’ve always been interested in light,” Takematsu said.
Back in her grad school days at the California Institute of Technology, a guest lecturer in geology took Takematsu’s inorganic chemistry seminar on a field trip to a natural science museum. The purple hues of the amethysts, the muted pink of the rose quartz and the luxurious olive green of the peridot, the professor explained, were the results of the d-orbitals and transitions the graduate chemistry students had spent so many years memorizing and understanding.
“It changes the chemistry when you put it in the sun!” Takematsu explained. “Light-initiated chemistry can actually change the coloring over time of some of these jewelry or ornament pieces that people purchase.”
Due to the effect of UV light, an amethyst left in the sunlight will slowly fade from a startling violet to the color of regular quartz. As a result, an amethyst crystal can tell you some of its history from its color alone, if you know how to look.
Takematsu’s current research is also about sunlight, in a way. Along with a team of other scientists, she studies a class of molecules called photoacids, which become more acidic when they absorb light. And more broadly, sunshine illuminates Takematsu’s world of chemistry in other ways, too. As she points out, the physical structure of tiny molecules can be revealed with the help of wavelengths of light up and down the spectrum of electromagnetic radiation.
“Most crystal structures, in the old days, used to be made with x-ray crystallography,” she said. “Now, people are trying to shoot [molecules] with electrons.”
Takematsu is adamant that people of all personalities can thrive in the sciences, and that science has something to offer to each and every student in return. In her “Chemistry for the Common Good” course, she has encouraged students of all majors, with interests in everything from government and economics to art history, to discover how getting down to the molecular level can contribute depth to their perspectives. In independent projects for the course, some students have explored the human rights crises behind the mining of rare earth metals for iPhones and solar panels. Other students have investigated the use of petroleum products in the fashion industry.
“We don’t really think of fossil fuels as creating clothes and plastics, but it’s the same chemical source,” Takematsu said.
Similar chemistry courses designed primarily for non-majors have created opportunities for students to address issues they are passionate about from a scientific perspective, transforming a sometimes intimidating discipline into a source of fun.
Jigyasa Subedi ’22, a computer science major, decided to enroll in a course called “The Science of Food and Wine” this semester in order to fulfill a distribution requirement.
“I’d been procrastinating on fulfilling that requirement, and every semester I would look at the class offerings,” she said. “I wanted to take something fun.”
After a rigorous curriculum of advanced science courses in high school, including advanced chemistry, Subedi was frankly burnt out from the discipline. Her elective this semester, however, has been a source of joy for her.
“I love cooking anyway,” she said. “Now I know and I’m like ‘Oh, wow, cool! This is why meat gets brown, and this is why wine tastes like that.’”
The hidden mysteries of the simple microwave, too, were a source of fascination to Subedi, and to the author of this article as well, who didn’t know how microwaves work. Subedi explained that microwaving leftovers won’t impart any flavor unto last night’s chicken, because the microwaves themselves—electromagnetic radiation of a certain wavelength—only cause the molecules of the food to heat up, without altering the structure of the molecules.
In a normal year, students in “The Science of Food and Wine” would get to play with ingredients in class, baking bread, making sauces and even attending wine tastings (for students of legal age). This year, however, students were given raw ingredients and left to test recipes in their apartments.
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