Because Sharon's regular classroom was having some work done, her class was in a different room, and did not have access to the materials Sharon had gathered for students to conduct the experiments they discussed the previous day. Instead, picking up on a comment that a student wrote in his science book about gravity, Sharon focused the day on talking about what causes gravity.

At the beginning of the video clip below, Sharon describes two ideas that students have mentioned about gravity. One is that that there is a magnet in the center of the earth, and the second is that there is metal in the center of the earth, and that we are a magnet. Sharon then reminds students that someone had said that gravity pushes on you, and therefore that gravity must be above you in order to push down. Students then bring up a third idea about gravity, that it is associated with the air in the atmosphere. Ray talks about two types of air: one that we breathe, and the other that's never ending. He associates the latter with gravity. Gustavo then raises the question: if gravity pushes you down, then how can you jump? Jose responds that it does push you down, but not that much, so you can jump, but not that high.

Some things to notice: (click to hide)

It is quite common for learners of all ages to associate gravity with either a magnet inside the earth pulling or the pressure from the air pushing down. These were the same ideas suggested by the students.
It's interesting that Ray distinguished between two kinds of air in the atmosphere: the air you breathe (and presumably is confined to being close to the earth's surface) and the air responsible for gravity, which extends into space.

The students continue to talk about the relationship between air and gravity. Jamir points out an analogy between trees making air for people to breathe and the atmosphere making gravity for the space. Sharon asks the class to raise their hands if they agree that gravity is above us (in the atmosphere) and pushes us down. Only a few students raise their hand. Osmary (mislabeled as Brittany in the captions), referring to what Kyleigh had read in a book, said that gravity was caused by a magnet in the middle of the earth pulling us down. Sharon then focuses on the distinction between gravity being outside the earth and pushing you down versus gravity being inside the earth and pulling you down. Jamir then provides an answer to the question Gustavo had raised a bit earlier about gravity not allowing you to jump. Jamir said that we are so far from the magnet at the center of the earth that it doesn't stick to us that well (doesn't pull on us that strongly), and therefore we can jump.

Some things to notice: (click to hide)

Both Jose and Jamir provide an answer to Gustavo's question about how we are able to jump if gravity is present (either pushing or pulling us down). However, whereas Jose just states that gravity doesn't push on you that much, Jamir provides a causal explanation in terms of the strength of a magnetic pull getting weaker with distance: we are so far away from the magnet that it doesn't pull on us that strongly, and we can easily jump.
Jamir's idea that trees make air for people, while the atmosphere makes gravity for the space, is supportive of the idea that Ray mentioned in the previous video clip.

Day 12