Responses to this tweet were the following:
- [Ask] ,"What keeps the moon going around the earth?"
- [Show] Bell jar or some sort of vacuum chamber I'd say.
- [Show] Videos of things falling in a vacuum. Or in your own bell jar?
- Show vids of astronauts walking on the Moon.
I'm wondering how the responses would have been different if the tweet had been this:
"In my class, several of my students were debating whether or not air is needed for gravity to work. As the conversation went on, more and more students were beginning to be persuaded that air is definitely necessary. What should I do to help keep the debate alive?"Then I'm wondering how the responses would have different if the tweet had been this:
"In my class, several of my students were debating whether or not air is needed for gravity to work. As the conversation went on, more and more students were beginning to be persuaded that air is definitely not necessary. What should I do to help keep the debate alive? I'm not convinced they have compelling arguments on either side?"
This is a good article about this exact problem, and one inquiry-based response to it: http://www.nap.edu/openbook.php?record_id=10126&page=475
ReplyDeleteThanks for the link Emily! I have read that, but I totally forgot about it.
ReplyDeleteInteresting about the correlation between airlessness and weightlessness, I'd never thought of that before.
ReplyDeleteIt still leaves me wondering about your questions, especially the second one. Any suggestions? My attempts to provide counter-theories that explain the available evidence seem to work only haphazardly. "What can you measure that would support your claim" sometimes helps but sometimes leads to more begging the question...
I think my biggest suggestion is to fuel students thinking by engaging with their ideas, even if in this case, those ideas are inconsistent with other things we know. I'm just not convinced that thinking that air causes gravity is a "bad" starting place. It certainly isn't where you want them to end up, but that doesn't mean it's not a generative place to begin, and the place to meet students and spend time there.
ReplyDeleteAlso, gravity is a puzzle, for all of us. For students, how and in what ways air provide forces like buoyancy and drag is also a puzzle. For students, it seems those puzzles are intertwined; and, if that's the case, we shouldn't pretend there not.
Lastly, "Gravity can exist without air" is only an observation, not an explanation or solution to any of those interesting puzzles; but somehow we get into thinking that showing them this observation (in and of itself) is worthwhile. Students certainly need data and observations, but they also need to feel like they have some autonomy over what counts as data and they need to feel some confidence in their ability to access those phenonema.
I agree about engaging with students' thinking. I'm not so worried about the times when their thinking is inconsistent with what we know (that tends to come out in the wash). I'm more worried about times when their thinking *is* consistent with what we know -- but it's based on invalid inferences, or it's tautological. I like the way you posed the question -- "how do I keep the debate alive" even though they've got the "right" answer, and they know it.
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