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.