Density and memory

Today's lesson topic was density. In keeping with Montessorian principles, the same materials can be presented to different age groups, with different levels of discussion. Thus, the K group simply holds and feels the three objects (see picture) and learns the word "density", where the EE group also weighs them. As soon as they get to long division in math class, we could bring the same objects back, measure their volumes by the Archimedean method, and compute the density.

Here are the three objects of different densities (and the scale).

Also in EE we can refer to other objects of higher density. I figure when they jump up and madly run for their astronomy books, desperately eager to show all the pictures, this is a good sign.

Last week's Science Magazine news-of-the-week gave us a discussion on Bacillus Thuringensis. For the K group, we go for the key concept: "These germs kill bugs that eat crops" (good timing, as the Gardening class has been suffering from an aphid attack on one of their cabbages). In EE, we point out the disturbing evolution of Bt-resistant pest insects (and alert students ask how severe is the threat to beneficial insects). Left for next year is the actual content of the article, which had to do with remediation strategies for Bt resistance in the context of genetic recombinants. And several years away are lessons on Monsanto politics… too complicated for now.

This week we did a memory experiment, which was so much fun I think I will add it to the standard weekly protocol.

Start by asking "who remembers last week's News Of The Week", and notice the unanimous response (sudden surprise: omigosh, I just realized I have absolutely no idea!). Then, drop little hints, ("does anybody remember trying to learn a long name. . . something about germs. . . the initials Bt…") and watch as the lights go on one by one around the room. I should probably videotape the whole sequence as there is a ton of good neuroscience in it. Like after about 9.2 seconds people start remembering the News from two or three weeks ago instead, and so on. Or, next class, how much faster will they remember Bt? (average time until the mouth bursts open in an "aha" response: might have been 30 seconds this cycle, will it drop? Linearly or logarithmically? etc)

Of course we also had stinky stuff and blew things up … goes without saying…