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Doing Real Science

March 28, 2014

We were talking about special relativity tonight in Physics 3 and we had a good discussion about relativistic mass. I wrote the expression m = m_0/Sqrt(1-v^2/c^2) and gave a hand waving argument for why we say that mass changes with velocity. A student then asked if mass *really* changes or if it’s just something we say to make the math work. Is there an experiment that if conducted aboard a spaceship and viewed from a different inertial frame would lead the viewer to conclude that mass had increased?

Relativity isn’t my strongest area and I didn’t know the answer so I started thinking aloud ruling out the first few potential experiments that came to my mind. A student looked like he had an idea so I passed the question to him and from there we had a great discussion with multiple people building on and refining each others’ ideas to try to come up with an answer. It was great and I enjoyed being a discussion participant on equal footing with the students.

On the drive home, I happily thought about how this was a good interaction where we were legitimately doing real science – proposing and refining ideas, trying to understand each others’ ideas, using analogies and counterarguments, etc. We’ve had a couple moments like this in Physics 3 and reflecting on them I realized that they all sprung from students asking a question to which I did not know the answer.

This leads me to ponder two possibilities:

1. Are there lots of other instances of real science occurring, but I don’t notice them as easily because they don’t involve *me* using the tools of science to answer a question that is brand new *to me*? Are there instances in which student-to-student discussions represent real science interactions but they don’t jump out at me as much because they are questions and interactions that I’ve seen before?

or

2. Do I inadvertently suppress moments of real science when I do know the answer? Do I answer too many questions or somehow indicate to the class that I know the answer and thus remove some of their motivation to contribute to constructing an answer?

It would be interesting to gather a collection of real science moments from the following categories: 1) student-to-student w/o instructor contributing, 2) student-to-student-to-instructor with instructor contributing when I do know the answer, 3) student-to-student-to-instructor with instructor contributing when I do not know the answer. Would there be differences in the genesis of the moments? In how students perceive the moments?  In how/when students contribute to the moments?

 

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4 Comments
  1. Andy "SuperFly" Rundquist permalink

    I’m always afraid that I’m doing (2) (answering questions too quickly). I’m also afraid that if I try to join in, they’re suspicious of me holding back on “the answer.” I’m curious, how long would you let them go with something like this? One class period? several? Until they get it? I know my experience is that I’m usually proud of myself if I come back the next class period with an “answer,” but I think I should just leave it on them longer.

    • It’s always difficult to decide how long to let them go. The examples I’m thinking about at the moment came about in whole class discussions. In these cases I’ve noticed after about 15 minutes that some students are checking out from the conversation (it doesn’t help that it’s a night class so it’s going on 10 pm). Once I notice multiple students checking out I tend to say ‘let’s continue this discussion on the online discussion board.’

      If it’s a topic that’s part of curriculum then I usually come back with an answer the next class. If it’s a tangential question then I’m more likely to let it sit over multiple periods and return to our questions/ideas as they relate to other topics we’re covering.

  2. Sounds like you want to give your students more opportunities to practice thinking like a physicist. Perfect tool for that: peer instruction with clickers. *Every* students participates (not just enthusiastic ones) and, with good choices to the multiple-choice question, you can direct the convo: each choice is a discussion prompt that helps each student sound like a physicist. Happy to suggest recourses if you’re interested. Peter

    • Peer instruction is a good tool and it’s one that I do use; although probably not as successfully as I could be using it. I do think there is a difference between me offering students four choices and them knowing that one of them is correct and students constructing and articulating their own hypotheses that may or may not include a correct answer.

      This is helpful thinking about the interactions I’m shooting for and their relationship to peer instruction. I agree that peer instruction can provide good scaffolding for these interactions. Maybe I could collect student hypotheses in these instances to be the choices for a “clicker question” which would give a little more structure to the discussion and help encourage students to articulate their ideas and decide whether or not two ideas really are different. This might also help students (and myself) see our interactions as lying along a continuum from instructor generated questions to student generated questions and from questions to which most of us know the answer to questions to which none of us know the answer, rather than as a dichotomy between “school questions” and “real science”.

      I have some resources related to clicker questions, but I’m always happy to collect more if you have resources you like. Thanks.

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