I can’t take credit for the title of this entry. Richard Dawkins used it in The Extended Phenotype, a book I’ve not yet managed to get through. It’s a lot more complex than The Blind Watchmaker, River Out of Eden, and, of course, The Selfish Gene. Maybe someday. But I love the quote.

“Reductionism is a dirty word, and a kind of ‘holistier than thou’ self-righteousness has become fashionable.”

The whole point of the whistle story is that the path to complex ideas and discoveries is paved with simple ideas and discoveries. This is of course a completely reductionist approach to education and, if you haven’t figured it out by now, it’s time for me to come out of the closet. Yes, I am a reductionist.

I don’t really think there’s a true difference between reductionists like myself and those who call themselves holists or systematists or the like. I think we really do believe the same things. For instance, I believe that “wet” is an emergent property. I don’t believe it’s magical, and I don’t believe “wet” has anything to do with anything other than the application of hydrogen bonding to things immersed in water. When I put my hand in the tub, billions upon billions of hydrogen atoms, with their partial positive charge, cling the atoms in my skin cells, and I feel “wet.” There’s nothing inherently wet about the H2O molecule – water vapor doesn’t feel wet until it condenses on your skin, and solid water doesn’t feel wet until it starts to melt. Yet “wet” emerges – a property of hydrogen bonds and water molecules with just enough, but not too much, kinetic energy.

I doubt that many who call themselves non-reductionists or holists or systamatists would disagree with this analysis. Some might disagree if I applied the same analysis to “consciousness,” but that’s another discussion.

So to get back to the whistle (and yes, this still has to do with reductionism). There’s another sense in which I am a reductionist. Not only do I believe that the road to complex ideas is paved with simpler ideas. I also believe that only a certain subset of those simple ideas are worth demonstrating.

Now demonstrating and teaching are not always the same thing. I also try to teach just with my words. But even here, I often (not always, but often) fall back on elegant demonstrations to describe simple ideas. The reason is that simple but elegant demonstrations are those most likely to be remembered.

For instance, suppose I wanted to demonstrate the cavity magnetron idea. A whistle is a wonderful allusion to the cavity magnetron, because everyone has blown a whistle. We know what it sounds like, what it feels like. We have a good idea that bigger whistles have a lower pitch than smaller whistles, and that no matter how hard you blow, you always get the same sound out of a whistle. When writing about the cavity magnetron, a whistle works well.

For a demonstration, though, it falls short. There’s nothing dramatic, interesting, or elegant about blowing a whistle. There’s nothing particularly surprising. It’s a bit like demonstrating gravity by dropping a ball to the floor. Sure it demonstrates the concept, but it’s not memorable.

Instead, I might use wine glasses with differing amounts of water. Like the differently sized whistles, the wine glasses, when rubbed, will sing with different frequencies. This demonstrates that the amount of water in the glass helps determine how fast the glass can vibrate, just as the size of the whistle helps determine how the whistle vibrates, just as the size of the cavity in the cavity magnetron helps determine how the cavity magnetron “vibrates” in tune with microwaves.

The wine glasses have the added advantage of being somewhat surprising, puzzling, and elegant. A beautiful tone emerges from a thing that is clearly not a musical instrument. How does it do that? Now I’ve got ’em!

In teaching with demonstrations, it’s not enough to find a demonstration that relates to a concept. You must also find one that is just plain fun to do.

Teaching is hard.

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