Teaching Earth Science

Last week was a bit of a surprise for me. The previous week I had met and spoken with the Earth Science teacher here at lunch. She seemed to be quite underwhelmed with the resources available in her classroom as far as available rocks and that sort of thing go. So I told her I would bring her some rocks from our lab since we had been cleaning out our rock collection. So I showed up in her class and she asked if I would teach a section on plate tectonics, particularly one on how paleomagnetics work. So I was suddenly teaching an earth science class with no practice or prep. Luckily I had some rocks with me. And I took some iron shavings and a magnet from the chemistry classroom to show students how crystals will align themselves with a magnet. So the lesson was pretty thrown together, but the students seemed into it. However, she had an activity for the students to do that she explained very little about before giving it to them, so the students didn't seem to really "get" what they were doing. I wanted to try to explain it better, so I went around to each group of students to try and get them to understand what they were doing. I don't think it worked very well that way. So for the next period I asked her to do it as a demo first, so the students would get what they were doing a bit better. That seemed to help, but her explanation wasn't very good. They just thought they were drawing stripes on a paper. I have since thought of a better way of doing this activity (more like Simon says, where we call out normal and reversed, one student draws on the paper every time it's reversed, and the other student just slowly pulls the papers apart the whole time). For a last-second lesson, I think it went pretty well, but it's hard to leap in without knowing what her ultimate goal was. So the second class went better because I knew where she wanted the students to end up, so I tried to guide them that way.