“Hi Dad.”
“Ben!”
“Are you busy?”
“No. I’m at a conference, but we just took a break.”
“Should I call back later?”
“No, no. Now is fine. What’s up?”
“Well,” he said, “I have some calculus questions.”
I thought to myself, well it this really is a call I needed to take! He explained how they’re doing optimization problems, and he proceeded to explain some problems he was working on.
The first problem: find the size of a cylinder inscribed in a sphere that has maximum volume. We talked the problem definition thru and I had him draw a diagram illustrating the relevant quantities, and within a few minutes, he was telling me how to solve it.
Then he described his second problem: finding a maximal volume cone. We talked again about the problem definition and discussed another diagram, and again he was telling me how to solve it in a few minutes.
Finally he described his last problem. This one, I confess, I didn’t master. I needed a pencil and paper and a few minutes to look at the problem and think. In the meantime, we discussed the problem definition, and I had him draw a picture. And as I talked my way in circles, he began to solve it.
And that was it.
“Thanks Dad. Are you having a good time at your conference?”
“Yeah,” I said in a fairly noncommittal tone, omitting that I really wanted to see that paper that was going on then.
“That’s good.”
“What have you been doing?” I asked.
“Studying in the library.”
Music to my ears.
And so that was the end of our conversation. We said goodbyes and I-love-yous, and I went back into Salon-1. As I closed the door behind me, the speaker said said, “And in conclusion…” I chuckled to myself.
That’s ok. I would catch his paper when he gave it again the next day.