Sunday, July 20, 2014

The phlogiston of education

 Astrology, alchemy, and education theory?

If you take a strip of magnesium, a metal, and light it on fire, you will get an incredibly bright white, searing reaction--it's used to give us the brilliant white highlights in fireworks.

When you are done, you will have a pile of ashy, powdery stuff. It's no longer metal, you just saw the metal burn up. You just saw incredible amounts of heat and light get released.

Would you expect the pile of ash to weigh more, less, or the same as the ribbon of magnesium you started with? The answer is obvious, no?

Until not so long ago, scientists were not sure what to do with heat--we've all been through the catechism of high school science, so we all know that heat is a form of energy (though nearly all of us have no handle on "energy").

Before we realized that air was a mixture of several different things and not an element, again not so long ago, scientists had a problem. (Scientists always have problems, that's the whole point of science.)

If you burn wood, you are left with ashes much lighter than the original wood. The ashes will not burn. The stuff that left the wood during it fiery transformation was thought to be phlogiston. As it left the wood, the wood became less flammable. Ashes, of course, have no phlogiston left, and therefore can no longer combust.

Wood releasing phlogiston. (Photo by Francisco Belard, PD)

Here's the problem, though--if you weigh the stuff left after you burn the strip of magnesium, it weighs more than the original stuff you started with. Something has been added! (We now know, of course, mostly through indoctrination, that the stuff is oxygen.)

We see the world differently now, though it's still the same world. Same magnesium, same charcoal, same air, same ashes. We just have a better handle on everything chemical now because we figured out through careful observations that what we believed to be true simply wasn't so.

Humans have been teaching each other things for a long, long time now. We know that learning happens, and we assume it's because of certain processes we attend to. Much of what happens in a classroom does help, and a lot doesn't, but we're still in the Phlogiston Age of Education--we attribute power to ideas that have no basis in reality.  The Learning Pyramid. Gardner's Multiple Intelligences. The 10,000 Hour Rule. Ad nauseum.....

This is not to say we need to blow up the classroom as it exists--a lot of what we do does work, but it's not (yet) clear why.

Still, our field seems to fall for every Sylvester McMonkey McBean that strolls into town, making fistfuls of dollars one way ($3 to put green stars upon our bellies), and then the other (only $10 to remove those same stars).

We can do better.
We must do better.

At least if we want this profession to last longer than alchemy did....

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