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Sometimes it's just fun to look at stuff.

Sometimes it's just fun to look at stuff. Like, say, paints that your local artist is using. Of course it's even better if you record your observations.

Here's a paint that is enhanced by the addition of tiny glass beads. When you paint with this stuff, your art work will be shiny like a roadside safety reflector.

So, what's it look like at low magnification under the stereomicroscope?

And what if we wash off the goopy paint part and isolate just a few of those beads in a drop of water under a compound microscope at about 100x?

How did the manufacturer manage to make those beads so smooth?

And

Colored mica flakes, blue and pink, give the remarkable shifting iridescence characteristic of "interference paints" made by Golden Acrylics Corp. Here you see the mica flakes in a paint sample, highly diluted and magnified 400x.

Science news this week was the story of a remarkable type of caterpillar which is a parasite on ant nests. You might know that ants communicate by smell, but did you know that ants communicate by sound too? The caterpillar makes a particular sound which the ants recognize as "I am your Queen Ant. Feed me now!" - - and lives a happy life of ease in the anthill, growing fat on the labors of enslaved worker ants.

If my migraine doesn't recur, I'll try to get back to the Miss Stone story later today. Now that I think of it, Miss Stone might have been a migraineur too.

Miss Stone's biology -- part 1 of ?

My high school biology teacher, Miss Stone, taught a high-intensity high-speed course for the aspiring science major. She taught it like a freshman course in a good university: fast lectures, a lot of reading, and high expectations for retention and comprehension. She even added extra after-school sessions in spring for those who were interested. Students who did well in the course and took the extra sessions would reliably pass the AP exam.

And then there was … the Microbiology Challenge. In the middle of the year, an extended lab project required us to grow yeast cultures in test tubes full of nutrient broth. She told us the goal of the project (which I don't remember now), and gave us practically no instructions. Week after week, puzzled and frustrated students (myself included) would find their test tubes, once again, contaminated. Where there should have been a healthy yeast population, there was a cloudy stinky mass of other single-celled invaders. I remember her peeking into the microscope and gleefully asking somebody, "Is that your yeast or your pond water?"

After a few weeks of this, 85% of the class that was still stuck; but we began to notice that 15% of the class seemed to know something we didn't know. They used a number of techniques such as passing a flame over the opening of the test tube every time they opened it for any reason. And their cultures did not get contaminated. Other students began to ask those 15% what they were doing, and word got around bit by bit.

Eventually, after the end of the project, the class as a whole was given the half a dozen standard microbiology methods – flame and so forth—that would allow anybody to do this culture growth successfully (and would have reduced the six-week project to a one-week project).

I still don't know where those 15% got the advance information. Did they corner the teacher after hours and demand extra help? Were they the children of professional scientists? Did they take the bus to Harvard and dig in the science library there?

The real agenda of this project was never stated. I can guess at two things Miss Stone might have had in mind.

1. Preventing contamination is really hard. Until you've failed twenty times in a row you won't appreciate this.
2. In real life, the "answers" are not given to you in advance. You have to use any and all means (teacher, parents, Harvard library) to solve problems that nobody even told you would exist in the first place.

These are both laudable purposes, but I left with a feeling of frustration around (2). In terminology I learned later in life, I would have said we were "set up to fail". Or perhaps it was a "sink or swim" type of test. Students who – somehow – had already at age 15 grasped lesson (2) were able to demonstrate it and appreciate the success it brought.

Next instalment soon. . . running out of time here . . .

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…

Local business helps again.

This time it's the Feather 'n' Fur Animal Hospital of 9125 Manchaca Rd. I got into a conversation with them last December when I realized how much microscopy they do - - counting white cells, examining tissue samples, etc. One of these weeks I'm going to get around to buying a good batch of stains so we can prepare really vivid slides for class, but in the meantime they volunteered to give me some nicely stained genuine veterinary slides for the class. So I brought in a blood smear and a little ear cytology slide.

Look how nicely those cells show up when you stain them. Anyway, for neither the first nor the last time, a local business earns a shout-out of gratitude.

One of the K students brought in a splendid gastropod fossil, but somehow immediately segued to arthropods, and so we learned a little bit of greek (arthros, pod, gastros) and somehow ended up talking about scorpions. They do love to tell personal stories in these classes, and last time I checked my Official Theory Of Learning, I think it said that when the lesson becomes personal then the learning becomes permanent. Not only were we regaled with everyone's tales of Scorpion Encounters, but one of us claimed to have a house and yard practically chock full of the little critters. Now if that is you, please do send one in for class (feel free to kill it first if you like), because I have a UV light and it is really quite neat seeing how scorpions fluoresce in UV light.

So there you have it - - once again the K ran out of time without even getting to the Question Box. We'll have to start the class next week with the Q B.

The EE class is divided into two sections - - half the class has Science Guy while the other half has Gardening Gal, then they swap - - and it's funny sometimes how the two sections will take off in different directions from the same starting point. After sharing today's news (Possible Breakthrough Malaria Vaccine), and the first couple questions, one group got onto Black Holes and - - that was it - - you get somebody excited about Black Holes (and light and perception and gravity and density) and they don't want to talk about anything else for the rest of the day.

The second group marched cheerfully through their questions and moved on to the microscopy instead. Of course they all want More Power in the microscope, so if you find an opportunity on a nice 1000x oil-immersion scope (stereo, with the nice wheel-driven platform), or a cheap used electron microscope, don't let it get away. (While you're at it, we could really use a particle accelerator around here).

By the way, I heard a glimmer of interest last fall about First Robotics competition. At the time things were too hurried and maybe most of our group too young. But I wonder if now is the time to start thinking about it for next fall?