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I found a fine 1/2 hour movie with the title “Why Is Science Important?” I enjoyed it very much, and if you’ve read much of this blog I think you will, too.

http://whyscience.co.uk/the-film/

Probably half my blog entries are on this topic already, but I of course can’t post the address without saying something!

There is of course no one answer to the question. The usefulness of science can’t be denied. The importance of it for our future is obvious. The medical advances, the identification of the ozone hole, the hopeful possibility of nuclear fusion are all reasons that science is deserving of our attention. But the narrator’s final points are (surprise!) the ones that resonate with me. I love that he finishes his film in a museum. What is a museum but a place of reverence?

Now reverence can mean a lot of different things to a lot of different people. To me, hearing a group of ten-year-olds say “woah” when they feel an invisble magnetic field, or watch as an atom explodes, is reverence. That’s my drug. That’s what I’m after, every day, that feeling of awe, that wonder at this deep and surprising universe we find ourselves in. We do science, we make science the subject of our art (and what is life but art?), because science can make us say “woah”. Science is important because we are human beings, and we want to know!

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┬áis 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.

Teaching is hard.

There is a certain perception about teaching, held by many who have never taught. It is that teaching is like making a sandwich. If you want your sandwich to taste salty, you add some hard salami. If you want it to have some creamy tang, throw on a slice of sharp cheddar. A vinegary bite comes from some good brown mustard. Thinly sliced tomatoes give it a cool, wet crunch.

OK, now I have to go make a sandwich.

Now that I’m back (chew, chew, swallow, burp), I want to show why teaching isn’t like making a (bite, chew, mmmm, swallow) sandwich.

We have outcomes from teaching – goals, behaviors, walkaway messages, proficiencies, indicators – call them whatever you want. They amount to the same thing. If you teach this, they walk away with that. Mission accomplished. Pass the pastrami.

But learners aren’t cold cuts, or even really good cheese. Instead, learners wander all over the bread like some wildcard spice you’ve never heard of. Outcomes are inherently unpredictable. And that’s what makes them so amazing!

Here’s a story that shows how unpredictable outcomes are, and by the end it will (I think) explain my title. But you never know. Unpredictable.

In the early days of World War II, the British were under fierce attack by the German Luftwaffe. Radar installations along the English Channel provided some warning, but those early radar systems had a fatal flaw. The waves they produced were long waves, anywhere from a few meters to a hundred meters long.

The problem with long waves is that they wrap around their targets. Imagine trying to pick up a pea with a catcher’s mitt. Just as the catcher’s mitt can’t locate the pea very well, the long waves can’t locate incoming planes. The signal they give might be one plane, several planes, or even a flock of geese.

The British needed radar that used smaller wavelengths. But no one knew how to make those shorter wavelengths, around ten centimeters long. No one, that is, until two researchers went back to basics.

When the invention that made ten centimeter (microwave) radar possible was shown to the Brits’ American allies, I.I. Rabi took one look and said, “It’s simple. It’s just like a whistle.”

Short wave radiation (microwaves) have more energy than long wave radiation. Visible light has more energy than microwaves. Ultraviolet has more energy than visible light (that’s why it can give you a sunburn). X-rays have more energy than ultraviolet. And so on. If you think about it that way, then creating microwaves is harder than creating long waves. But Rabi and the British researchers had both looked at the problem in another way.

A whistle isn’t much of a musical instrument. Unlike a clarinet or a flute, it gives a single tone. Change the size or shape of the whistle, and you change the tone. But tone is to sound exactly what wavelength is to radio, microwave, ultraviolet, etc. And, as Rabi saw, a whistle is to music exactly as a microwave producer (called a cavity magnetron) is to microwave radar. No matter how hard or soft you blow into your whistle, the same sound comes out. No matter how much or how little energy you push into a cavity magnetron, the same microwaves come out.

With this new invention, the Allies found the German planes, found the German U-boats, and won World War II. You might have used that same cavity magnetron to heat up your chocolate chip cookies this evening. After the war the cavity magnetron became the heart of the “radar range,” what we now call the microwave oven.

Here’s the point. If you start off trying to defeat the Germans, much less warm up your cookies, if that’s your behavioral outcome, how in the world do you start with whistles? The only chance of getting there is to be curious about everything, to build a basic understanding of how the world works, of how ideas like waves (radio waves, sound waves, water waves), atoms, and energy help us organize the world. You can’t just push buttons, like adding ingredients to a sandwich.

Instead you plant seeds, like the whistle idea someone once planted in I.I. Rabi’s mind.

You never know what might grow.

My first book, called The Turtle and the Universe, was published by Prometheus Books in July 2008. You can read about it by clicking on the link above.
My second book, Atoms and Eve, is available as an e-book at Barnes and Noble. Click the link above. You can download the free nook e-reader by clicking the link below.
April 2009
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A blog by Stephen Whitt

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