Back in July, Physics Today ran an article on Reinventing physics for life-sciences majors (I couldn’t find an un-paywalled version, but this arxiv preprint seems to be close to it). As I’ve had some bad experiences with that class, I flagged it as something to read, but only got around to it last night. The main idea is that a “Physics for Life Sciences” course needs to be arranged around the way biologists think, which is fundamentally different than the way physicists think:
In general, physicists stress reasoning from a few fundamental principles—usually mathematically formulated—and seek to build understanding from the simplest possible models. They view the world quantitatively and pay much attention to constraints, such as conservation laws, that hold regardless of a system’s internal details. Biologists, on the other hand, focus on real examples and emphasize structure–function relationships; they rarely stress quantitative reasoning. The systems they deal with are almost always highly complex, with many interacting parts that lead to emergent phenomena. Biologists recognize that their discipline is subject to the historical constraint that natural selection can only act on pre-existing molecules, cells, and organisms, so their reasoning often depends more strongly on what exists than on “fundamental” abstract principles or simplified pictures.
Because of their focus on real systems, some of the biologists we spoke with considered traditional
toy-model physics examples—even such central and powerful ones as the mass on an ideal spring— to be irrelevant, uninteresting, and useless until physicists were able to show their value as starting-
point models for relevant, real-world biological examples. To do so required making it clear from the
first that a Hooke’s-law oscillator is an oversimplified model, then illustrating how the model would
be modified for realistic cases.
That sounds great, and some of the suggestions they make for curricular reform sound interesting. I have two problems with it, though. The first is just that going too far in the direction of shaping the course around how biologists think seems counter to the whole purpose of having people take courses on physics from physicists. After all, exposing students to the way physicists think is kind of the whole point– they should be exposed to methods that make (most of) them a little uncomfortable, and ways of thinking about problems that are fundamentally different.
I don’t think the authors would disagree all that much– their main goal seems to be wrapping some physics-y processes in biologist-friendly packaging, to make the unfamiliar thought processes more palatable. But this is the kind of idea that can easily be taken too far, re-shaping things to a degree where it doesn’t actually provide any benefit in terms of exposure to other modes, so I would recommend a bit of caution here.
The other objection is more practical, and may have to do with the fact that they may be seeing a different population of students than we see. Because while I think their course sounds great from the standpoint of presenting relevant physics in a package that will benefit research biologists, that’s not the problem we have. The negative experiences I’ve had with students in the life-science course are less the sort of thing that comes from biology-style thinking and more the problem Thoreau describes, namely that “Pre-meds are more helpless than a marsupial infant in the pouch.”
Our “Physics for Life Sciences” course isn’t generally populated by students who are going to go on to graduate research in biology (those students are slightly more likely to take the engineering sequence, of all things). It’s full of students who think they’re going to be doctors, and are taking the course for two reasons: 1) because medical schools require it, and 2) because there’s a physics section on the MCAT. They don’t hate the class because they don’t see the relevance to biological research, they hate it because we don’t just give them a set of simple algorithms that tell them the exact steps they need to follow to solve the problems that will be on the MCAT. It’s not an exercise in interdisciplinary exchange for them, it’s a test-prep course.
Given that, I find some of the recommendations a little hard to imagine putting into practice. The call for more realistic situations and context-rich problems, for example, seems like a recipe for disaster. Whenever I’ve attempted anything in the life-science class that involved any ambiguity or need for individual judgement, the process has been infuriating for everyone involved. “Discovery” style labs without cookbook lists of instructions have been an absolute catastrophe.
Now, it may be that this stems from the fact that we’ve always used curricula that more or less follow the engineering format with a bit less math, the approach which the authors of the Physics Today piece disparage. It’s conceivable that a more truly bio-centric approach would bring the attitude around a bit. But that sounds like a whole lot of work and a huge risk, given that what our life-science students say they want (both in comments on course evaluations and through their actions in class and in lab) is in almost exactly the opposite direction.
It seems to work for the authors of that piece, though, so maybe it’s worth thinking about. They have another preprint describing Maryland’s program in considerably more detail, if you’d like to know more. Personally, though, I’m inclined to continue to avoid that course to the greatest degree possible…