Introducing Physics and Astronomy to Kids These Days

Some thinking out loud about intro curricula

One of the many things fighting for bits of my attention these days is a nagging concern about our ability to interest students in our majors. The thing we’ve been doing for many years now hasn’t quite stopped working, but it’s definitely not working as well as it used to.

Some evocative nonsense generated from “connecting physics and astronomy”

Explaining what I mean goes way back, to the Late Twentieth Century, before I was hired. At that time, the department was having difficulty attracting majors, in part because they were just trying to peel students off from the intro engineering courses. But there’s only so interesting you can make blocks sliding on inclined planes, and those courses run in the Winter term so there was nothing in the Fall for entering students who might have a latent interest in physics and/or astronomy to spark.

One of the things they tried to boost our numbers was the creation of a Fall term “First-Year Seminar” course (PHY-100 is the current course code, so I’ll use that name), that isn’t officially part of the major sequence, but gives new students a bit of a taste of what we do. The format for this was a team-taught survey of the department, with five faculty each doing a two-week module on a topic relating to their research (I would do two weeks of lectures on laser cooling, for example, while one of my colleagues talked about dark matter). I think they ran it for the first time around 1999-2000.

One of my now-retired colleagues who was around for the launch of PHY-100 credits it with a significant increase in the number of majors. My first year on the faculty, we had only two graduating majors, but within a few years, that picked up to high single digits, where we’ve stayed pretty consistently since. There are a lot of fluctuations in that— statistics of small numbers, don’t’cha know— but we’ve averaged something like 9 majors/year for a good long while.

In the last several years, though, there’s more and more of a sense that PHY-100 isn’t working as well as it used to. While I try to keep this from being too much of a Kids These Days gripe blog, in this case I think there genuinely is a bit of a Kids These Days problem. Where in the past the “sampler pack” model for PHY-100 worked reasonably well, it feels like our last few rounds find it overwhelming. Changing topics every few weeks is a little overwhelming for them, not necessarily because the material is all that demanding (when I do it, I pitch it about to the level of a public lecture), but because they’re having more difficulty with the whole College Thing. As a result, we’re seeing some of them kind of flailing wildly in the class, and others just checking out entirely— not coming to class, not handing work in, etc. I don’t know that the conversion rate of PHY-100 students into Physics majors has actually gotten significantly worse— statistics of small numbers, again— but things feel off from the faculty standpoint, and there are more signs of student dissatisfaction than in the past.

Some of this is probably a lingering Covid effect, and some of it reflects a change in personnel over the years— when I started here, there were three of us doing research involving lasers and optics, so there was a decent chance that at least a couple of the modules could build on one another. (One colleague used his module to discuss the physics of lasers, and I’d go next to talk about using lasers to cool atoms, etc.) We don’t have that consistent natural connection any more, so the transitions are more drastic and disorienting for students who are also trying to sort out the whole “Being away from home for the first time” thing.

To some extent this could be patched up in the current model with a bit of coordination of topics, but we’ve tended not to do that— each faculty member has control over their own two-week module. Moving away from that would be a shift already, and if we’re going to do that, I wonder if we shouldn’t just look at a more comprehensive overhaul of the whole concept of the course. Which I will now proceed to think-out-loud about here.

While the above lays out some of the down sides of the modular structure, there are good points as well: the current format introduces students to five different faculty covering a range of different topics, giving a good chance that something will align with their interests. It also allows us to make sure there’s some reasonable coverage of both of our main subdisciplines— when I assign faculty to it, I try to make sure we have both physicists and astronomers represented. It would be a shame to lose that aspect of the existing course. But five very different topics is clearly too much.

So, I’ve been toying with pitching an overhaul that would cut the faculty down to two— one from physics, one from astronomy— and present something with more of a through line. That way we could get something more coherent in terms of the material that could still serve as a broader introduction to us and our activities.

To give a concrete example, one possible version could put me together with a colleague who studies the structure and motion of galaxies. These both rely very heavily on the properties of light and atoms, in a way that can tie together both atomic and optical physics and large-scale astronomy.

On the physics side, I could start with the basic question of the nature of light, going through the evidence for the wave model (diffraction and interference), then moving to the particle picture (the photoelectric effect) and finally connecting it to the structure of atoms (Bohr model, spectral lines). On the astronomy side, my colleague could do basics about observational astronomy (magnitudes and distances, standard candles, etc.) and astrophysics (Newtonian gravity and Kepler’s laws, etc.).

Then we could tie the two together by talking about galaxy rotation curves and dark matter: how spectral lines allow the determination of relative motion through the Doppler shift, and why the spectra we see suggest a huge amount of unseen mass. You need both pieces— classical and quantum optics, and astrophysics— to put the whole picture together in a satisfying way.

This model would give more of a through-line to the course, and allow for a bit more development of core college skills along the way: homework assignments that build on each other, etc. There are also some good opportunities for hands-on activities— diffraction and interference, photoelectric effect, line spectra— and potential use of real astronomy— my colleague has sometimes used our observatory to measure the motion of the moons of Jupiter as a Kepler’s Laws activity, or used small radio telescopes to measure the Doppler shift of gas clouds in the Milky Way to demonstrate the rotation.

The one potential snag here is that I wouldn’t want to lock in any particular pair of faculty for this— one of the nice features of the five-module version has been that a significant number of faculty get to make a pitch to recruit research students, and I’d like to be able to keep rotating that around. But I think there are options for tweaking this to involve other pairs of faculty. We have a new colleague who does work on gravitational waves, for example, which is another field where discussion could pair nicely with discussion of interference and diffraction and atomic physics. One of my colleagues has run a class on Astrobiology a bunch of times, and we have a computational biophysicist on staff, so there might be some connection there. Another colleague studies planetary science using our small particle accelerator to do experiments on the diffusion of metals, so there could be a version that pairs her with our accelerator manager. And so on. I think there are a bunch of ways to configure this that would make connections between core physics topics and core astronomy topics in a way that would hit the same basic beats without needing to be the exact same course every time.

Administratively, there are a couple of details that would be a little bit of a headache— moving from five faculty each doing a couple of weeks to to making a more substantial commitment would complicate the staffing of courses somewhat, and there’s the question of how to manage the rotation of topics. There’s also a bit of needle-threading involved in making a course that’s more coherent and substantial that still isn’t required for the major. But I think those are solvable problems, and there’s an opportunity to do something that could turn out to be pretty cool.

The tricky part, of course, is finding a way to fit working on this in around all the many other things I’m supposed to be working on…

---

I’m not sure how interesting this is to anyone else, but it’s sort of helpful to me to type it out. If you’d like to see more noodling about curricula, here’s a button:

And if you have suggestions of topics, or reasons why this will crash and burn with Kids These Days, the comments will be open: