Friday, August 19, 2011

Moving to WordPress

As of this post, I'm still trying to boss around the code there, but from here on out, please find this blog at:

I have been hasty about it, and have not been careful about preserving connections.  I apologize for that inconvenience to...


Wednesday, August 17, 2011

Understanding Confusion

Illustration by Jonathon Rosen
More and more, I not only try to teach Physics, but I try to teach my students something about learning as well.  I want them to know that when they struggle, their experiences are normal.  They're in the 9th grade.  They are just learning to think.

Learning to think necessarily drags one through...

And you know what?  This is a good thing.

All of the sudden, their brains are in conflict with their guts. Hooray! Believe me, some folks never get there. Recent studies by Eric Mazur (an elder statesperson in Physics Education research) and also by Derek Muller (a recent Phd sparking a lot of conversations) have shown that clear, precise explanations without introducing a conflict can actually make students perform worse; we humans tend to view the world through our own personal lenses, and seek reinforcement of our views. We see a news-story, and we become more firmly entrenched in our previously held beliefs. We see a carefully explained physics demonstration, and our preconceptions, our misconceptions, take further hold. Dan MacIssac writes in The Physics Teacher:

Muller’s Veritasium videos are powerful reminders of the need for genuine student struggle, engagement, and discourse to achieve growth in conceptual understanding of physics, of the remarkable lack of effectiveness of clear exposition and memorization (a.k.a. pseudoteaching) in promoting sophisticated conceptual change, whether in person or via multimedia, and the inability of most people to critically monitor and assess their own learning.  

And so, it is the end of summer, and I am welcoming a new group of students to the struggle this year. Some will lean in. Some will muck around and find footing. Some will get frustrated and hurt, and I'll be working furiously to try and maintain their trust so that they can find their way to understanding. Which they can do.  I hope we all have an inspiring and fulfilling year together.

As I was writing this, I remembered a poem by Robert Graves.

In Broken Images

He is quick, thinking in clear images;
I am slow, thinking in broken images.
He becomes dull, trusting to his clear images;
I become sharp, mistrusting my broken images.
Trusting his images, he assumes their relevance;
Mistrusting my images, I question their relevance.
Assuming their relevance, he assumes the fact;
Questioning their relevance, I question their fact.
When the fact fails him, he questions his senses;
when the fact fails me, I approve my senses.
He continues quick and dull in his clear images;
I continue slow and sharp in my broken images.
He in a new confusion of his understanding;
I in a new understanding of my confusion.



Tuesday, August 9, 2011

Happy Birds!

On using flipbooks in Physics


I love the idea of students making flipbooks to demonstrate physics concepts.  Last year, one end-of-the-year-project option was to make a flipbook that showed projectile motion.  Students were to incorporate 20 frames of hang-time in their books, and they worked out the position of the object in each frame (most all did this with a spreadsheet).  It was a useful exercise in scaling, as well.  For the animation itself, many used Flipbook! with a grid-printed transparency taped over the computer screen.  Some drew traditional analog books; a beautiful objects to hold in your hand and then keep in a shoebox under the bed.  Some cut out multiple pictures to glue on each frame.  

I still have some thinking to do about how best to have students demonstrate that they understand the underlying concepts.  Hmm...  Maybe next year, there will be a track with the director's commentary or an interview.  A good number of students drew a lot of satisfaction in the work, and yet a few never quite dug in.


Do you make flipbooks in your classroom?  What tools do you use?  What have your student made?

Flipbook! online maker
FlipBook Lite app for iProducts
Graph paper
Google Images for clip art

Thus far, I've avoided commercial software, but I'm interested if others have used any.

Monday, August 8, 2011

Greatest Hits: Simple Circuits, The Foutan Board

I thought I would post a few labs or activities that have been big winners with my students in engagement and learning, whether or not I designed them. This one comes via Cornell's Center for Nanoscale Systems Institute for Physics Teachers (CIPT). (Do a find for "foutan"* on the page.) There are parts lists, lab handouts, and teacher notes available there. Hot tip from the author, Jim Overhiser: short dowels on the corners (as pictured) make for good stacking.

Update: Here's a nice redesign they've made at Cornell.


What came before:
  • Students lit a bulb with a battery and a wire
  • Students dissected a bulb to trace the loop
  • Students set up series and parallel circuits to observe brightness of bulbs and generalize rules

What they learn with this activity:
  • Utility of circuit diagrams
  • Gain comfort with diagrams
  • Gain comfort with series and parallel
  • Trouble-shooting, such as finding that two bulbs are equally bright -- are they in series or in parallel?  Unscrew to test.

Why I love it:
  • Lighting the bulbs is an engaging puzzle that motivates the need for circuit diagrams.
  • Students are tracing paths on the diagrams, reinforcing a good model for current.
  • Instant feedback and revision  (The bulb didn't light! Try again...) 
  • Students come out with good feel for series and parallel.
  • Boards can be used in other settings for quick set-up of many simple circuits; students like the quick usability.
  • Students loved this and were wildly productive for a solid 90 minutes.

Some notes:
  • Some students will want to approach this somewhat randomly -- flick several switches, then look up what's lit.  Watch for and cheerfully disarm this practice; they won't learn much that way.
  • The leads from the 9V are usually the least hardy components.  I change the batteries.
  • Not everyone has to finish the first page.  
  • There are plenty of sophisticated puzzles in the mix.  They are not in order of difficulty.
  • I projected the diagram on the white board, and students would come up with markers to work through together, sometimes across groupings, on the challenging ones.

How will you know if students are applying a viable conceptual model for current?
  • Have them rank these circuits according to the brightness of bulb A.  (Note that we do all this before introducing any formulae; they come later.)

*Foutan: The person (a former grad student at Cornell?) who designed this ingenious circuit.  Pronounced like the bed, futon.

Friday, August 5, 2011

How I became a Physics Teacher

I'll likely be keeping this blog pretty straight Physics & Education with this exception, as the tweet pictured was my entrĂ©e into Twitter society.

For several years after high-school, I was working minimum-wage, hardscrabble jobs. Self-serve gas station, fence-painting, farm hand, embroidery machine operator, alterations. I eventually fell into sewing for a living, and wound up sewing out of my home, then outside of Nashville. Wedding gowns and country music recording artists. The drummer I'd married split (I bought him tires for the truck; I know there's a song in there), and one night, I was sitting in a bar at a showcase, where unsigned artists perform for music industry people, and I was hating the Whole Scene.  I was such an outsider.  This was not my dream. I turned my head away to hide the tears. Surely I have something more to give than making clothes to fuel industrial idolatry.  Then a warm glow filled the room. Wait a minute! I don't have a husband to support, I don't have kids or a house payment… I could go to school! 

July 1992
My mother (who had passed much too early) told me I could be anything I wanted when I grew up, and now was the time to make it happen. I pored over course catalogs. (Anthropology! That sounds fun… Archeology! Cool!)  I was thinking some flavor of Environmental Engineering would marry my passions and skills, when a friend passed along to me this issue of Scientific American.  He thought the COBE data were pretty cool, in his Scientology sort of way.  I confess: it didn't hook me.  (Please bear in mind that I hadn't taken Physics in high school.  I'm not even entirely sure that girls could!)  However... there was this little article in the back that somehow caught my attention: "Quantum Philosophy" by John Horgan (@SciAm).  I read it and reread it.  And again.  I'd never heard of wave-particle duality.  Wait.  You twiddle the beam over here, and it affects what happens over there?  Wait, how was that set up?  I've probably never worked so hard to understand a magazine article; I surely hadn't before.  (Physics journal articles I've read since don't count!  ;)  

So this is Physics, I said to myself, and was delighted that it appealed to me in such a poetic way.  We don't know everything!  This was my first exposure to Physics, and I loved it.

Meanwhile, I'd enrolled in the local community college to try and remember math (and learned that it was sooo much easier if you did your homework).  I took a Chemistry course at Tennessee State University.  I applied to "elite" colleges thinking it would be an honor to get in, but I would instead have to spend 10 or 15 years taking classes at a state college while working full time to get by.  I'd already received a few acceptances, but when I opened the envelope from Dartmouth, I couldn't breathe.  I could barely breathe for three days, because of the Really Big Numbers in the financial aid package.  (Teachers!  Tell your students that it can cost needy students less out of pocket to go to a private college than it does to go to the local state university!)  At age 32, I packed up my belongings and headed to the dorm.

College was wonderful.  Truly life-changing.

I ended up sticking with Physics over Engineering, largely because of my physics Professor, Dee Mook.  Thank you, Professor Mook, for all of your encouragement in all aspects of life.  Come sophomore year, I was sure I wanted to teach.  High school.  The subject almost didn't matter.  Come senior year, John Horgan (@Stevens), the author of the above article, gave a talk at Dartmouth.  I got to tell him that his article was the reason I fell in love with Physics, and now I've told you.

MotoGP: lean machine, part 2 — the Dani data

I rather like the idea of putting Dani Pedrosa's clip from the last post in front of students and letting things be very open -- open to estimation, as well.  But if one would like to hone the quantification, here are some resources.

What does he ride?  
Honda RC212V

How big is he?

How sharp is that turn?
Type "Sachsenring Germany" into Google Earth, and it will take you right there.  Here's a fun puzzle -- which turn on the circuit is he making in this screenshot?  [Spoiler alert]

Note that the shape of the riders' turns is not the shape of the road; they're quite skilled at that whole Principle of Least Action thing.  I love how you can see the blackening of the road from the tire-wear from space.  I approximated the turn with the red circle below; if anything, it's a little small.  The ruler-feature on Google Earth is mighty handy here.  I love how you can see the blackening of the road from the tire-wear from space.

Alternately, the circuit specs are here, and here's a map that could also be used to approximate the curvature.

I'll be doing this for sure when I get back to Physics with 11th & 12th graders!

Monday, August 1, 2011

MotoGP: lean machine!

Nicky Hayden (Owensboro, KY)
leads Jorge Lorenzo in Spain 2011
My husband turned me on to Moto GP this summer.  As a rider myself, I find what these riders do just so viscerally exhilarating, I can hardly bear to watch.  If you have not yet seen a motorcycle race, please know that these guys are dragging their knees on the turns, often with the rear end of the bike (or the whole thing!) sashaying in the limbo between static and kinetic friction.  (Here's Casey Stoner drifting; watch as he comes out of the turn.)  The angles are so insane that anyone (not just physics geeks like me) wonders how in the world they are able to do that.  So naturally, I start looking for the perfect clip to lay on my students, and I give you Dani Pedrosa, under the radar gun.


After about 20s, Pedrosa's speed is displayed.  Student questions will drive the analysis.  Have fun!

I've added this one to the collection of clips for Video Analysis that I started in last spring.  The picture is sharper in the original than above.