What's going on in there?!?!

I spent part of one morning last week talking with one of my kids' kindergarten class about space. Now, for those of you who have not spent time with the five-to-six year old set, kindergarteners are fascinating. They are clearly emerging as people with well defined personalities and outlooks, and they give the impression that they are at last inhabiting the same rational world in which most adults live. You can reason with them, making them ripe for discussions about scientific topics. For example, while they all had learned that the Sun was a star, and that real stars were "round" like the Sun, they had never really thought about the 3-dimensional shape of the Sun. The class was evenly divided between thinking the Sun was shaped like a ball, or that it was flat like a frisbee. But, after talking with them about how we orbit the Sun, and ...