Experiments, quizzes and Pimsleur, and bubbles

The nematode experiment was a resounding failure. Remember we had these beneficial nematodes which are supposed to help gardeners by preying on grubs. So, I got two beakers, and dug up a couple grubs, and put one grub in each beaker (along with some vegetation and dirt), and then added nematodes to only one of the two beakers.

Both grubs died.

Learning opportunity: failed experiments are a constant in the scientific process. For every ingenious experiment that advances The Cause, there are hundreds that just fizzle out and fail to teach us anything at all. All this trying and failing is the creative process that leads you to devise a real winner of an experiment.
In response to this, we spent part of the class trying to think of better beneficial-nematode experiments. We didn't come up with anything so compelling that I want to rush ahead and try it, but the kids threw in some pretty good beginnings of ideas. We'll return to the subject next session.

Onward to the quizzes. Last year, when I wanted to learn some Arabic, I purchased the Pimsleur Method instructional CDs. One thing I noticed was that after they taught you a new word, they'd go off onto other content for about 90 seconds, and then ask you out of the blue to repeat the new word. You could just feel the darn thing trickling down the memory hole "dang it, they taught me how to say The Store Is Closed and I nearly forgot!" , and I'm sure the point of it was to catch that moment and cue your brain to transfer the word from short term to middle term to long term storage. (After the 90-second interval, they leave it for 180 seconds and then ask you again . . . etc)
With this in mind, we tried our first Science Test. Naturally this was nothing like those paper things with 100 multiple-choice and 50 short-answer questions, and all your prestige riding on the results. Think of Test as a synonym for Experiment. "Hey, let's do a brain experiment. I wonder how much is left in your brain from what we learned last week! Do you remember the part about the black holes or the sugar crystals or the intestinal cells? Was it trickling out the memory hole?"
Preliminary results:
1. We remember some very detailed information while at the same time totally losing other details. And I mean totally. Big, blank, empty space.
2. We remember some core concepts while at the same time totally losing other core concepts.
3. If student #1 remembers "A" but forgot "B", then student #2 might remember "B" but forget "A".
Interesting things, brains. You know that the ability to forget is essential to true intelligence, right? Collecting mountains of data is all very nice in its own way, but the real value is in organizing and structuring the data. Think of the last time you did a big garage organization project. Your most powerful ally? The trash can. The same is true of data in memory. Structuring requires weeding. And learning requires mistakes – such as overaggressive weeding of the data.

Of course we also had a fun demo. One of our Primavera parents led me to this one. (hint, hint: do you know a neat thing to do in a science class? Don't keep it secret) . This one is easy to do at home. Just throw some yeast into a bit of hydrogen peroxide. The yeast sets about destroying the (poisonous) peroxide, reducing it to oxygen and water. The sudden production of oxygen means . . . . BUBBLES ! . . . which means . .. WHOOPS OF JOY! For more spectacular bubbles, add a bit of soap before you add the yeast.