First-Year Students Explore a Deep Mystery in Innovative Physics Class
The syllabus for James Battat’s first-year seminar Physics 100 Einstein and the Dark Universe (cross-listed as Astronomy 110), which he debuted last fall, sounds as enticing as a movie trailer—yet the intrigue and the drama are real.
“Astronomers have uncovered a deep mystery,” the course description begins. “Measurements of galaxies, galaxy clusters, and radiation from the early universe show that only ∼4% of the mass-energy budget of the universe is understood. The rest is ‘dark’: dark matter and dark energy. The unknown nature of the dark universe is one of deepest questions in physics today, and has caught the attention of thousands of physicists across the world (not to mention the general public).”
After that effective preview, Battat, assistant professor of physics, explains that students are in the center of the action. For 13 weeks, they apply Einstein’s theory of general relativity to model the evolution of the universe across cosmic time and to quantitatively explore the astrophysical evidence that reveals the presence of dark matter and dark energy (which exerts gravitational effects on visible matter and the large-scale structure of the universe).
Think that sounds specialized? Think again, because Battat designed the hands-on course for a wide range of first-year students: astrophysics aficionados, the curious but undecided, the “I’m definitely not majoring in STEM” crowd, and those nervous about their scientific ability. His only requirement is that students be willing to take risks and to expand their understanding of the invisible components of the universe, about which we know so little.
“Dark matter is all around us, literally streaming through our bodies at astounding rates. Millions of particles fly through your fingernail every second,” says Battat. “All the light collected by all the telescopes ever used has revealed a tiny portion of what’s out there. In effect, we’re only seeing shiny sequins, but are blind to the underlying fabric of the universe.”
The 12 women in his inaugural class, most of whom did not plan to major in physics, studied and examined that fabric each week through problem sets and archival data sets analyzed with the widely used Python programming language. Quantitative analysis with Python enabled students to find evidence of dark matter in other astrophysical systems (e.g. galaxy clusters) and of the expanding (and accelerating) universe through galaxy and supernovae observations.
Students also uncovered firsthand evidence of dark matter in our galaxy through telescope observations of hydrogen gas clouds orbiting the galactic center. While recording radio-frequency data at the Haystack Radio Observatory in Westford, Mass., one student smiled widely and said, “I can’t believe we’re actually measuring our galaxy!”
As fall turned to winter, the first-years designed and carried out a six-week independent research project that required hardware design, computational modeling, and/or numerical analysis. That project was the most challenging part of the course, Battat says, as each student encountered dead-ends, had to redefine her research questions, and experienced frustration before finally enjoying success.
“A common misconception about physics is that all the rules are known. But really there are huge open questions, and plenty of room/need for creativity,” he says.
The students’ creativity led to impressive results, with one woman weighing the black hole at the center of our galaxy, and another investigating the habitability of extrasolar planets through dark matter capture rates. There was even a group of three that built a radio telescope. “How incredible is that?” a classmate said. “No matter where they go or what they do, those students will be able to look back on that experience and the perspective it gave them.”
The desire to help students expand their perceptions of the universe and their own abilities motivates Battat every time he steps into a classroom. “I want them to experience firsthand what research tastes like, and how it feels to hover on the edge of ability and comfort,” he says. Discovering new aspects of oneself is crucial, he believes, no matter what field of study one ultimately pursues.
Every student in his inaugural Einstein and the Dark Universe class agreed with that assessment by the end of the semester. As one woman wrote in her course evaluation, “Learning about physics or the universe isn’t just helpful for those intending on becoming astrophysicists. There were a lot of times I looked at a problem in the homework and said to myself, ‘How in the world am I going to be able to do this?’ Building that confidence and perseverance in the face of a seemingly insolvable dilemma extends itself to every aspect of life.”