I write this one day before the Astronomy class final, two days after the last class session. It’s the fourteenth time I’ve been in a similar place on a December weekend. Every year is the same. Every year is different. This year 38 students completed the journey with me. We still have that final to take care of tomorrow but I miss them already. For the most part, it was a breathless run for them, I suppose. Certainly if anybody thought we were going to learn constellations and star patterns all semester they were likely surprised, no more than anyone who expected things to be mostly about how cool black holes are.
It was a struggle. It was meant to be. In part we struggle with difficult ideas because that’s how real growth occurs, an idea that gets lost in the shuffle sometimes. Occasionally students wonder why I ask them to work so hard on something that has nothing to do with their majors. “Exactly,” I respond, “You have four years to figure things out in your major. We only have one semester to do the heavy lifting.” More to the point, the struggle we undertake is meant to mimic humanity’s struggle to comprehend the universe. We start by trying to deduce what we can learn by simple observations of the night sky. For example, the flattened nature of the solar system becomes apparent when we plot planetary positions over time on a constellation chart and the difference between the sidereal and solar days shows itself when we measure stellar positions relative to the horizon over the course of a few weeks. After the sidereal day project students complete two more: (1) measuring the position of the moon relative to the ecliptic in an effort to determine the tilt of the lunar orbit relative to the ecliptic; (2) measuring the reddening of stars in different directions in order to understand if dust and gas are distributed uniformly in the Milky Way. We calculate maximum wavelengths of emission and luminosity variations with temperature and radius. We move on to discuss galaxy formation and the history and future of the universe, just a few of the things we do.
Even with all the graphing and calculating the course is still a liberal arts course. My aim is for the most important point that students take away is how very human this effort has been and continues to be. People make mistakes. People fight. People make beautiful, breathtaking leaps. What emerges is a staggeringly broad and deep self-consistent model of our universe. How can we know all this? It seems impossible; I hope we have taken the steps carefully enough that just maybe it seems like it might be possible. It’s a beautiful story but importantly it is our story. It is possible to interpret much of the story as diminution of humanity. We grow ever smaller, relatively, and less central as the story unfolds. But the story we have developed! It speaks volumes about what it means to strive and learn and be human. For any diminution there is surely equal part elevation.
And so this is where we ended two days ago, cleaning up a few dark matter concepts, doing 9 practice clicker questions as a refresher for tomorrow’s final and me somehow not sure how to encapsulate the remarkable nature of what we just encountered together in a way that didn’t seem fake or cheesy. After all, it was just one more course they needed to take to graduate. And now I feel the oh-so familiar post-semester malaise, not quite a funk. It seems like a scam that while people suffer the world over I am able to make a living talking with students about the universe and our interaction with it. In some ways it feels like the movie Groundhog Day telling essentially the same story every fall to a new group of students but when it ends I am never quite ready for it to be over. This year the students were great. Really, I can’t recall ever having a better group. I asked them to dig in and truly engage hard concepts. They responded with their very best, growing all along the way. I am sure that on this night they are anxious about the final and not thinking about all we have done but I hope that in some way, even if not right at this stressful moment, they can step back and take it all in.