Caveat: The Karma Professor Explains the Mpemba Effect

I had a class last night with my highest-level students, the TOEFL 8th graders, that was close to an ideal type of class, in my opinion.

Nominally, we were working on the TOEFL speaking questions. But before class, one of the students, Sumin, had asked me if I knew anything about the "Mpemba Effect" (see wikipedia – I'll not try to replicate the explanation found there). She had to make a speech about it, in Korean, for her Korean-language class. In researching it online, she'd found more materials in English than Korean, and, being an ambitious and motivated English student, she decided these were legitimate sources for putting together her speech. She was checking with me mostly to make sure she understood some of the technical aspects and the fairly specialized vocabulary of chemistry and physics involved. 

So we carried on our conversation about it into the start of class. The other students overheard and were curious, and so I started explaining. And then I said, "Actually, this is exactly the kind of topic that they put into a Type 6 TOEFL speaking question." You listen to some complicated lecture on a difficult topic, and then you have to summarize.

Somewhat jokingly, I asked them if they wanted to do a speaking question practice on the Mpemba Effect. To my surprise, they were enthusiastic about this idea. So I pulled up the wikipedia article, scanned through it to make sure I understood it, and then proceeded to give a 10 minute lecture, more or less, on the Mpemba Effect. This included digressions to explain concepts such as convection, insulation, dissolved gases, crystallization and "seeding" crystals (i.e. catalysts), and several other things that occurred to me. Then their job was to give a one minute summary, in the TOEFL style, of my lecture.

In his summary, David even included the expression, "The Karma professor explains…," a joking reference to my sometimes being identified by both students and coworkers as a "professor." It's a moniker that seems to follow me regardless of career. 

The class was ideal. We covered what we needed to cover – which is to say, we did TOEFL speaking practice on a particular instance of what are always essentially random topics. Yet the students themselves selected the topic, out of interest, and they more or less led the class in terms of what was expected of them. I was just a kind of resource, an on-call "professor" that they could hit "play" on for various aspects of the topic in question.

[daily log: walking, 7km]

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