Lawnmowing, Studying, and Testing

A couple of years ago, I bought a push mower. I mean an old-fashioned reel mower that has no power other than that which you give it.  I love that thing even though it doesn't really do a good job (or is it me that is not doing a good job?).  Recently I had to consult the owner's manual to fix something and I wound up re-reading the "suggestions for best results" section.  Now I KNOW I read that section carefully when I first bought it (I had never even used a reel mower before then), and I even REMEMBER reading it.  However, rereading after actually using and struggling with the mower for a couple of seasons, the suggestions had a different meaning and deeper significance to me.  I was in a position to appreciate and understand what they were getting at!

As it is final exam season at school, my mind first went to studying and the undervalued experience of rereading stuff you think you already know.  As a student, I used to focus on the stuff I felt like I didn't understand at all when studying for a test.  However, it is now clear to me that reviewing and rereading (at least the chapter summaries) the stuff you think you do understand can take your understanding to the next level.  It is a different cognitive experience to read something with a pre-existing understanding than it is to read about something for the first time!

Finally, my thoughts turn to the utility of final exams themselves.  Recently I have been asked why do I give final exams at all?  Trumping all the other reasons I have, I'm thinking the forced revisiting of topics you think you understand can be the potentially most enlightening moment of the course...

Graduation Day

CL takes a selfie with me on WHS graduation day:

Climate of Fear or Sketchy Dad?

I'm lucky enough to live within walking distance of the high school where I teach and the elementary school where my kids are students.

Usually my wife meets them after school and walks them home, but sometimes it's my turn.  One day, as I was walking from the high school to the elementary school, a friend slowed down in his car and offered me a lift. I hopped in and he dropped me off across the street from the elementary school.  Since I had my school issued laptop and the wifi signal is the same district-wide, I took my laptop out in front of the school in order to do some work.  I'm now 10 minutes early and progress reports need to be sent out, so I perch my laptop on the corner of the building and start working.

After a few minutes, the school secretary appears next to me and says, "Excuse me, can I help you?".  I look up, totally confused, as there are at least a dozen parents now standing around waiting for the dismissal in order to get their kid.  So, I say, somewhat uncertainly, "Uhh, I'm here to pick up my daughter?"
"And what's her name?"
"Isabelle.." (for the record, I know for a fact there are at least a dozen Isabelles of some flavor in that building)
At this point the secretary is close enough to see my district-issued laptop and ID badge.  She gets a bit embarrassed and stops asking questions.  I lean in close and whisper, conspiratorially:
"Do I look suspicious?:
Super-flustered, she goes back inside.
A minute later she pops out a side door and talks to me from the side of the building where the gaggle of moms hanging out near the front door can't see her.
"Um, I'm so sorry about that - it was the fact that you were dropped off by a car that then drove away.  Usually parents either drive or walk and are not dropped off..."
We laugh and I go back to work.

But...
....why didn't one of the parents come up and talk to me directly?
Why were they so worried anyway?
Why didn't they mind their own business?

Climate of fear.

Parents worry about their kids all the time.  Worry about what we feed them, about the air they breath, the fabrics they wear, the words they hear.  Everything in life is a potential mis-step that could ruin their lives.  Every random element in the world is probably going to kill them or mess them up.  People call the cops when they see kids playing in a park unsupervised.  We're scared to let our kids walk home by themselves at ages we did the trek by ourselves back in the day not because we're worried about what will happen to them -  we're worried that other adults might turn us in for being "negligent parents" or seeing "abandoned kids.

Or, maybe, I just look sketchy and should dress nicer...

Fathers, Sons, and Mending Fences

This past week I replaced a couple of broken posts in my fence.  Sebastien popped out and started to help out.  He dug a bit, he helped with a couple of screws, and he helped me move some stuff around and line it up.  I mean, he actually helped move the project along rather than simply slow me down!  As I enjoyed this moment, my thoughts turned back to similar moments in my youth helping my own father out with some kind of fix-it project in the mid 1970's.

Now I think, does every father live in two places at once every time this happens?  My son helping me connected to my own (albeit distant past) helping my dad?  Did my dad think about helping his own father some 60 years ago and did my grandfather in turn have that metacognitive moment back in 1950's?

As every small boy feels the pride of the first time "helping Dad", does it reverberate through the generations like dominoes?

Dumb Questions

"There are no such thing as dumb questions!" is something my students have been telling me for years.  One of the many things I love about teaching older students (usually they are 16 or 17 when they take physics with me) is that I joke back "Really?  C'mon, we all know some questions are kind of dumb, right?"  They laugh and I laugh and we move on.

This year, however, my classes and I have been exploring this idea a bit more.  Sometimes we share a metacognitive moment: "Was that a dumb question?" or "Did I just say something dumb?" (I ask it of myself out loud as well as of my students). What has started to crystalize in my mind is that they are all dumb questions.  Aren't novice learners of physics filled with dumb questions?  And aren't they suppose to ask them and have me answer them?  If what we mean by saying something dumb like "there are no dumb questions" is really 'ask every question you have!' wouldn't it be equally effective to say "they are all dumb questions, but go ahead and ask them!"?

I'm thinking that the mantra "there is no such thing as a dumb question" may actual stifle questioning since most students are somewhat aware that there is a good chance that someone is going to think their question is dumb. So, I'm thinking, let's go ahead and acknowledge that they are all dumb up front!  In the past I have identified a question as especially dumb if I just answered it or the answer is on the board or the student could have answered it themselves with a millisecond of reflection.  But now I think that is not the classroom I want to have: fire away with your dumb question and simply forgive me if I get a bit exasperated or silently point to the answer to your question on the board.  Your job is to ask the questions and my job is to help answer them!  Also, reflecting on equity, almost all of my own questions to the class are dumb "What page is the problem set on?" "What number [problem] are we working on?"  "When does the bell ring?"  Pretty dumb stuff, right?

This year I have been especially helped in my thinking by eavesdropping on a trio of girls in the front row of one of my classes as they engage in group work.  They have a nice stream-of-consciousness style about them and I have gained many an insight listening in.  Beginning physics students are fumbling around with new vocab, new equations, new skills, etc. and it's a messy process getting to the right answers!

"There are no dumb questions" = "All questions are dumb"

"...the opposite of one Profound Truth may very well be another Profound Truth."  - Niels Bohr

Best Seller?

My respect for "Best Sellers" is gone.  Apparently the secret is to have a category so narrowly defined, your book winds up being #1.  Check out this screen shot from amazon.com:

Backstory: I did some editing/reviewing for Barron's in the past and when the author of their current AP Physics B book declined to reorganize and realign it with the new AP Physics 1 and 2 exams, they asked me if I would take on that piece and become a co-author. An interesting experience and a lot more work that I ever anticipated, but now I, too, am a "best seller"...

TV star

The year is 1990 ( +/- 1 year).  I am working in a lab at Purdue, making mirrors for astrophysicists.  They are looking for faint blue light released when cosmic rays hit the Earth's atmosphere.  A very (now) dated show called "Beyond 2000" comes to do a profile of the scientists I work for.  They needed some action shots and so a star was born (I appear briefly in 3 scenes: don't blink!)

Father, Son, and Haircuts

Historically, we had a lot of trouble convincing Sebastien (now 6) to get his hair cut.  About a year ago, I got us synchronized so we are both due for haircuts at the same time and this seems to work as he sits still for me (sort of) in order to give him a buzz cut.

This weekend, we partook of the ritual and this morning, over breakfast, we were talking about our matching haircuts and Irene says to Sebastien "You're so cute with your new haircut".  So I chime in with "Almost as cute as me!"

Sebastien laughs and says "No, you're almost as cute as me!" (points to himself dramatically with his thumb).

Slight pause and then he adds, "I mean, not even close, because you are so old..."

Excellent Sheep and What makes a Good Shepherd?

The other day, when we were going over some homework in class, I sort of pretended to not know how to solve one of the problems.  I was pretty believable because earlier that day I had gotten a bit stuck and, before I could even start brainstorming, a student bailed me out with a great suggestion.  I enjoyed that moment so much - I was looking to recreate it.

However, at least one student (and where's there's one expressing, there are at least a dozen thinking the same thing) expressed incredulousness that I would assign a problem I was not one hundred percent ready to lead them through.  Something really bothered me about that reaction but I couldn't quite put my finger on it.

Yesterday, I was skimming (seems to be all most nonfiction books merit these days for me) through a book I picked up at the library: "Excellent Sheep: The Miseducation of the American Elite..." by William Deresiewicz.  The premise of the book is old hat to me: our best and brightest seem to just be gaming the system and going through the motions of education in order to move onto the next stage in life (see my old post on educational mercenaries).  The author seems to be laying the blame primarily on those institutes of higher learning that the elite go to (fits the bill for many of my students so am I part of the problem?).  Although I reject his premise - I think the problem is cultural and not institutional (what messaging did your parents give you about education?)- I did find a gem of a reminder in there:  Good teaching is about leading and modeling a search for understanding rather than relaying information.

So, even if I do know how to do the problem - I think I'm going to feign ignorance up there on the board more often and hope someone steps up and tries to help me out!

Shedding light on Blackbody Radiation

Was there ever such a terrible name given to a phenomenon?

The art teacher tells them that if they mix all the colors, it winds up black.  But I tell them white is all the colors mixed together.  What gives?
White is the equal stimulation of all three cones in your eye.  So firing all the colors at once into your eye is indeed what white is. Black is the absence of stimulation - so no color.
When you say something has a color, you probably don't mean it.  Unless it glows in the dark, what you mean is that that the object reflects that color.  A red shirt in the dark does not look red - it looks black, it only looks red if there is some some red in the light striking it so it can reflect red.  So, when you mix all the "colors' in a painting or drawing, everything gets absorbed and nothing gets reflected and it looks black.

Blackbody radiation is what physicists call looking at something's actual color.  Rather than looking at the reflected colors, we look at the emitted colors.  Your blackbody radiation peaks out in the infrared because of your body temperature.  The fire in the fireplaces peaks out in red. Anything hotter than a few 100 degrees does not have a blackbody radiation spectrum that is black!

So a red shirt is not red, white light does have red in it, and the blackbody radiation of a fire is actually red.