We spent a lot of time today working on our model of circuits, especially around the difference between lightbulbs all in the same loop and lightbulbs each in their own loops. One group talked about how lightbulbs all in the same group are "longer." I like that metaphor, especially when I think now that lightbulbs, each in their own loops, allow "thicker" path for charge to flow. I wish I had taken pictures of the students' thinking.
We then went into lab and looked at how long bulbs and round bulbs act when put in the same circuit. It's weird! We tried to explain it with electric pressure, but we don't feel very comfortable with it. We'll spend a lot of time tomorrow trying to understand this new model of electric pressure. So far, our idea of electric pressure comes from the battery, where the battery makes positive end have more than the usual amount of charge so the negative end therefore has less charge than usual. This difference in charge density can allow a flow to occur if there' s a continuously conducting loop connecting the positive and negative end of a battery.