346. Science, just for fun

rat-hereTeaching should be fun for teacher and student alike. That’s my perspective, but I have to admit that I had it easy on that front because I taught science. Science is full of falling things, and flying things, and squishy things, and stinky things. If I had to teach English, or social studies, or math, I would certainly have a different view of how much fun teaching is.

Here is an example. CH4 is the formula for methane gas. Teaching chemical formulas could get a little obscure and uninteresting if you let it, but there are always “interesting facts” that you can throw in to help keep things rolling. For instance, methane is what comes out of the gas pipes that you cook with if you live in a city. It’s also what comes out of cows and ends up in the news as a bovine generated greenhouse gas. If you leave a stove on without lighting it, you smell it, but methane is odorless. How does this happen? The gas company puts a chemical in with the methane that stinks when fresh, but burns up without stinking if a fire is lit.

This is the point when some wiseacre will say, “If methane is odorless, why do farts stink?”

And you can answer with a straight face, “Well, if you consider where they come from, and what the gasses have to push their way through, and the little particles they are carrying with them . . .”

If you can’t make science fun, you probably shouldn’t be teaching it.

One of the things that come up in middle school science is the conservation of matter. Matter is neither created nor destroyed, except in nuclear reactions; it just changes form. Methane gas combines with oxygen to create carbon dioxide and water. You know the equation, and you’ve probably had to balance it. My students had to do it, too. You have to do the work if you are going to learn.

But there is nothing wrong with spicing things up occasionally with an illustrative story. Even Jesus used parables.

Consider the story of Billy, who never believed what he was told.

I would begin this story with a drawing on the board like the one at the top of this post, except that there would be a cartoon of a dead rat, on its back, where the word “rat” is.

The story begins — When Billy came into science class one day, his teacher had put a dead rat on a scale and covered it with a bell jar. The scale read 7262.5 grams, the weight of the bell jar plus the rat. Billy’s teacher said, “This is part of a two week long experiment. Don’t touch the setup.” Then he taught something else.

The next day, things didn’t change. After the third day, the rat had started to swell up. (I didn’t take two weeks for this. The whole story took about fifteen minutes. At this point I erased and redrew the rat with a distended belly.)

By Friday, the rat was huge, and it was all Billy could do to keep from lifting the bell jar and poking it. But he didn’t. Even though the rat was huge, the scale still said 7262.5 grams.

Over the weekend, the rat blew up. When Billy came in on Monday, there was nothing left but a skeleton wrapped in a busted skin, with a few oozing guts. The air around the rat was kind of brown and the scale still said 7262.5 grams

(At this point I had redrawn the rat to match the description. This was also the point when I elicited from my students just what was happening and why the scale still read the same.)

Billy just didn’t get it. He couldn’t understand why the scale stayed the same when the rat was reduced to almost nothing. His teacher had explained that the rat’s mass had been converted to gasses which were trapped in the bell jar. Since the gasses could not escape, the scale had no reason to change.

Billy didn’t believe it. It had to be a trick. While his teacher was across the room, helping one of his fellow students, Billy slipped up to the teacher’s desk, took hold of the bell jar, tipped it back . . .

There was a pop and a hiss as the bell jar came unstuck. The scale dropped to 6571.3 grams. The students in the room screamed, leaped up holding their noses and yelling at Billy, and ran for the back of the room . . .

You get the point. They got the point. And we had a lot of fun besides.

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