The rubber met the road today for four of our groups. This was the first opportunity for groups to try out material they had developed on the rest of us (in student mode) and solicit feedback about it. It was an incredibly insightful day for me and our group didn’t even get to present yet!
The groups that presented today included an underpinnings unit that ran us through a measurement activity, a physics group who had us develop Ohm’s Law and two chemistry groups. Now, I’m unfamiliar with chemistry modeling but I was immediately struck by the notion that we were no longer dealing with things but instead with the idea of things. There were no hydroxide ions in front of us, only a blue liquid, a clear liquid and a sensor that gave us some number. And when learning about reversible reaction rates and equilibrium, the activity actually required us to represent concentration of reactants and products with volume of water in straws. Both activities were well constructed and interesting to me, but the level of abstraction required as a student was significant. According to the teachers, not every activity is as abstract as those today, but when you’re driving principle is that the entire material world is made up of tiny particles, you can’t really avoid it. As a chemistry teacher, it falls on you to construct opportunities for the students to develop this model, and if that fails, you need some means of convincing them. The only reason they have considered this particle model as a possibile explanation of reality is because you suggested it. Contrast this with physics, where students already have a pretty developed set of models to explain the world based on their own observations.
As a physics teacher, I want to bring more of modern physics into my classroom but to do that I have to confront the same challenges that my chemistry colleagues do. How does one tease Placnk’s constant from the light of LEDs? Or the idea of dark matter from galaxy rotation curves? Are high school students cognitively capable of making these connections? I think back to how excited these ideas made me when I discovered them in high school (Yes, I was a geek even then.) and I want to share that excitement with my students. No one thinks physics is cool because of boxes on inclines. It’s cool because it predicts weird things beyond our imagining and then proclaims that they are real. No other high school class can do that. I don’t know how to bridge this gap yet, but I need to figure out how.