Showing posts with label mythbusters. Show all posts
Showing posts with label mythbusters. Show all posts

August 01, 2013

New tag in Evernote: Show-to-students

I have a new tag in Evernote  I called it Show-to-students. I have tagged everything clipped recently from the web that I want my students in the Fall (and semesters after) to read. These are articles, essays and blog posts which highlight ideas I think are important for the learning process. I'm sure I found all of these via my twitter stream, so I want to thank you all for posting them to twitter, whoever you were.

So far, I have five items to share with my classes.

The most recent one that I found is the excellent post on ConvergeDiverge about the teaching philosophy that Maxwell had. I think Heather has a great insight that we as instructors have a struggle with some (or many) of our students between how deeply they want to think about the topics we would like them to think about. As my comment (and Heather's reply) indicate, I think it could be helpful to address this issue at the start of the class as a part of setting the tone and expectations for the class early.

Another article that I'd like to share with my class is the article from Slate on the inability of students to effectively multitask. The article includes this nugget:
During the first meeting of his courses, Rosen makes a practice of calling on a student who is busy with his phone. “I ask him, ‘What was on the slide I just showed to the class?’ The student always pulls a blank,” Rosen reports. “Young people have a wildly inflated idea of how many things they can attend to at once, and this demonstration helps drive the point home: If you’re paying attention to your phone, you’re not paying attention to what’s going on in class.” 
I don't know if I could execute that move in class unless I've told the class to read this article in advance. I'd also consider using Patrick Len's excellent approach to cell phone / social media use in class: poll the class and use the class discussion to set the cell phone / social media policy.  But really, I just want students to be thinking about how much they can actually learn while they are trying to multitask.

When I looked at my tagged articles, there was a surprising pattern I had not expected: three of the five articles were about the role of failure in learning. I must have been channeling a certain skateboarding physicist when I was tagging these articles. "Failures, Mistakes and Other Learning Tools" was a blog post that sat in one of my browser tabs for MONTHS last year. I was really inspired by how this teacher handled his student's confrontation with failure for the first time. The blog post on Scientific American which told the story of Feynman's attitude toward being wrong in science should be mandatory reading for all future scientists. Then there is this incredibly honest piece on Slate by a math teacher on what it was like for him to have been "bad at math" and how that experience ultimately made him a better teacher. I'd like to connect that idea to the growth mindset that Dweck writes about in her book.

I saw a question on Quora that also connected failure with learning.  It was good, but I'm not sure if I'm going to add it to the list. I might just leave my students with Adam Savage's catch phrase: Failure is always an option.


April 06, 2011

Mythbusters need to spin more science



I want to like this segment that the Mythbusters did on the merry-go-round spun by the bullet.  I think it's an interesting question based off of a scene from a movie: Is there enough kinetic energy in a bullet to spin a merry-go-round.

A proper analysis of the question could involve kinetic energy, rotational kinetic energy, torque, angular speed, angular acceleration, angular momentum, friction, air resistance and potentially other factors.

The Mythbusters only vaguely waved their hands at some of these ideas and presented physical parameters in weird units.

The voice over in the above video said "First, the science of spin..." then proceeded to say very little about rotational motion.

Grant talks about how the bullet has to "overcome inertia".  Okay....I mean, we tell physics students that in rotational motion it is the moment of inertia that matters, but I'm willing to let it slide. EXCEPT, he then pulls out a force gauge and measures how much force is needed to just get the merry-go-round to move. But, since we care about the rotation of the merry-go-round, it's the torque that matters.  Plus, what he really is getting at is a measure of the coefficient of static (rotational) friction on the axle.

There were a lot of other problems with the things the Mythbusters said in the segment.  Some of what they said was just using colloquial terms for physical properties which a physicists would not use.  I'm not so terribly upset by those comments.  I'm just bothered by the lack of coherent explanation of the physics of the system.  I came up with a simple analysis of the experiment, using parameters provided in the video and considering just conservation of momentum. I don't claim it to be a full treatment of the question, just more of a back of the envelope type calculation.  (And I don't take friction into account, either.)

I turned my calculation into a pencast:


Analysis of Mythbusters merry-go-round question