Since childhood, I’ve known that heat rises. They taught me about that in elementary school, and then they did some “experiment” to show us that they weren’t kidding – that it really does rise. I got the impression that science was a method used to prove that what you already knew was true, was true. I got the same impression of geometry; it was a bunch of proofs that were basically unnecessary.
It wasn’t until yesterday that it occurred to me that there’s a reason hot air rises – that molecules move around faster, bump into each other, and bounce off each other, leaving extra space between them so that hot air is lighter than cold air, which doesn’t rise. There’s still plenty of mythology and faith involved in that explanation, but at least “hot air rises” now has some company in mind; it’s not a totally isolated myth.
When I call these ideas myths, I don’t mean they’re not true; I’m commenting on the way they’re often taught and learned.Teachers “cover” the concepts, and children have to show that they “know” them. After the dust has settled, the concepts may have been “covered,” and children may “know” them to varying degrees, but many children end up thinking the way I thought for forty years: hot air just plain rises. Why? Because it does.
Yesterday, I observed a good science lesson. Children saw a teacher hold a plastic bag about twelve inches above a flame. As she held it there, she asdked the children what they thought would happen if she let go. Those children who had answers seemed to agree that the bag would rise to the ceiling. When the teacher let go, the bag did rise, and then it fell back down.
The children wanted her to do it again, and she did. Then she asked them why the bag had risen. They talked about hot air balloons, explaining that the heat made the bag act like a hot air balloon. That answer was good enough for some of the children but others wanted to know why a hot air balloon works. The discussion made me think of the children as hot little molecules, all bouncing off each other. It was pretty exciting.
The teacher may have had a deeper understanding of what was going on than the children had. And perhaps what I was finally realizing, after forty years of not thinking about it, was worth voicing. But I kept quiet, and the teacher did not offer an explanation, either. There are plenty of times in school when explanations from adults are very appropriate. But there are also times when children ought to be free to speculate – to search for their own explanations. Allowing that freedom can be difficult for adults who think they “know” the “right” answers; are children really learning if they’re playing with “wrong” explanations? Yes, they are.