Today was very teacher-centric. I don't know how I feel about this. For one, this is difficult stuff to conceptualize, and for me to be there, introducing parts of it here and there and letting them try some problems about it, works better. They have some pretty strong models on the electric force and on waves that we can build on. I also feel shakier about this unit, which I abbreviate PMAM (the particle model of all matter), than any other unit this year.
I know I could make it more modeling-friendly. I could give them results to experiments and have them come up with explanations. But what those experiments look like, and what makes the data seem real rather than just words on a sheet of paper, isn't clear to me yet.
It's okay that I'm not done with this unit. I can see the improvements I can make in previous years. It's not like this year isn't successful. The derivation of the Bohr atom went smoother this year than ever before. But there's still more to do to perfect my practice.