jumpingfish

QED 1

Some time ago, I went through a proof of the quadratic formula with the pre-AP kids. It was part of our notes. I put the proof in their homework. The proof was an extra credit question on their test. At the end of the proof, when we had arrived at our destination, I wrote on the board: QED.

I turned to the kids.

“Quod erat demonstrandum,” I said. I rolled the r’s. I flattened the vowel sounds. I did my best to sound exotic.

“What’s that!?” a student asked.

“That which was to be shown,” I said. “It’s latin”.

And I repeated it again.

QED 2

We did another proof a few weeks ago. Frankly these proofs are not so much proofs per se as derivations. So yeah. We derived something else. And when we got to the end, I wrote: QED.

One of the students said, “Tell us what that stands for again, Mr. Hasan.”

Of course, they knew what it stood for. What they were asking for was the latin. They wanted to hear it.

“Quod erat demonstrandum,” I said. I rolled the r’s. I flattened the vowel sounds. I did my best to sound exotic.

Professor Langebartel

When I was an undergraduate at the University of Illinois, I took a Differential Equations and Orthogonal Functions course from Dr. Langebartel. He was awesome, so awesome that when I needed a math elective to finish my minor I chose Tensor Analysis simply because he taught it.

Dr. Langebartel once stopped a lecture and asked us, “Who was the greatest mathematician in history?” He waited briefly, but this was a rhetorical question. He answered it himself.

“Eudoxus,” he said.

We were in an auditorium in Altgeld Hall (which is going to get a facelift soon). I can still hear his booming voice in that large hall drawing out his sibilants: Eudoxxxxxusssss! And he told us a story about Eudoxus.

It was a surprise to have a professor give historical context in a technical course. No other professors I had did this. He was the one from whom I first learned QED. And I still remember how exotic it sounded for him to draw out the latin pronunciation. Clearly my students feel the same way.

My students thank you for those lessons, professor.

After a full day of environmental consulting from home, the fair and industrious Trudy headed out to Costco. I did not go along — no need to double the size of our target, and anyway, my contribution was in the 60+ line at Whole Foods and hour before opening this morning. (Age has its privileges. But I am not over 60 yet, so I am not yet in that demographic. I have two days left.)

Instead of a Costco run, Izzy and I took a leisurely stroll.

We saw two girls taking a video of a caterpillar climbing the trunk of a tree. We saw yellow and red Indian Blankets blanketing a neighbors’ yard. We saw Prairie Verbena with lavender blossoms and Blue Eyed Grass colonizing the soccer fields.

We looked for Oak saplings in the grassland that the middle school kids are creating in that field. Last fall, I did some guerrilla acorn planting there, but there was nothing to show for it except the grasses waving in the wind and a fluttering bird that we startled. That the little grassland is now an avian habitat is something, I suppose, but I was hoping for evidence of Oaks.

We saw a man throwing a frisbee. He threw it hard, and his barking dog would excitedly dash off only to stop well short of halfway from where the disc landed. Not much of a frisbee dog. Izzy seemed never noticed. Not much of a frisbee dog, either.

And finally, somewhere in the distance, I heard bagpipes. At least I think I did.

Ok, stop it. there are two days before I am formally over sixty. You may snicker at the bagpipes then. 

Oh joy. A friend sent us seven rolls. 

Wait. How do I take a selfie with this thing?

Here is “Thursday’s thought” that I sent out to my students this morning.

I have always identified closely with our older dog, Charlie. He was a “senior dog” when we adopted him a few years ago. He was so laid back, unlike that hyper puppy that was hopping in my wife’s lap giving her kisses. Charlie seemed to be meditating, sitting motionless, staring into the distance with half-opened (half-closed?) eyes. When Trudy looked at me, she knew who we were adopting.
 
Charlie is our Zen Dog. He’s mostly quiet (quieter as the years pass). He walks pensively around the yard. He wakes up stiff in the morning. He stumbles around for his first few steps. I sing good morning to him to help him wake up.
 
I wonder what he thinks about “the man” singing in a lousy, scratchy, low morning voice, the man’s chin against the dog’s head. I wonder what he thinks about that.
 
For that matter, I wonder what YOU ALL think about my scratchy, off-key voice when one of us has a birthday. My brother told me once, “You shouldn’t sing so loudly.” I should probably apologize for that (and to Charlie). But then, a sung song is a good thing. … Right?
 
That’s all I got. 
 
Students: expect a call from your 3RD period teachers today if they haven’t already called. In fact, it would make things easier for them if you EMAIL THEM with a phone number that you’d prefer to be reached at. We’ve got Skyward numbers, but I know those numbers aren’t necessarily the best ones to reach you. Let your teachers know what number they should use. It’ll make it easier for them to check in with you.
 
You are awesome.

This was today’s daily note to my students and their families.

Hi folks,
 
We (CCHS) will be trying to contact students (yes – TALK TO YOU) today or tomorrow. We have a few questions that we’ll ask to help us figure out how to plan for the future.
 
In the meantime… Here’s a word for the day: “wend”.
 
This word means to “proceed toward” or “move in the direction of” or “make progress toward”. You would “wend your way to the finish line,” which is not the same thing as WINDing but rather MOVING GRADUALLY FORWARD. I’ve used it… like… twice  :-)  but it makes me think…
 
Years ago I ran marathons: Chicago six times, Austin once. I was a “mid-pack runner.” PR: just 3:42. Marathon running taught me two lessons which could be useful now…
 
1) One step at a time. You can’t think about the entire race all at once in a marathon. It’s 26.2 miles, and that’s just too far to grok (a word for a different day). Heck, 26.2 is too far even when you’re at 18 miles and the skyline of Chicago seems to be very far away! You take one step. Then you do it again. And again. – For now: Let’s not worry about when we’re going to be back at school. You shouldn’t worry about grades. We should just keep ourselves well and take it one day at a time.
 
2) Hold your head up. A long distance run is hard if you stare at your feet. Even if you’re committed to taking one step at a time, there are so many in 26.2 miles. If you dwell on each step, it seems like it’s taking forever. I found that my long runs and marathons went by faster (and more enjoyably) if I held my head up, and looked into the distance. – For now: Even though I’m taking one day at a time, I’m holding my head up. Sometimes I go and sit outside. I feel the sun and see purple spiderwort and verbena. I hear the wrens and robins. I talk to the dogs. And the days pass quickly. 
 
If you can see this picture, here’s what I’m talking about.

(If you can’t, it’s my cartoon dude running along a very long number line, head held high.)
 
Be well. You are still awesome.