Sunday, October 01, 2006

Detour, Week 2

We had our second night of Detour this week. Overall, things went a little smoother, but even the first week wasn't very chaotic. We had a few more kids for homework help and tutoring, which is great. I think that will really continue to grow. I had to fill in again for science and since I had a boy the first week that really wanted to learn about light bulbs, we did light bulbs and electricity this week.

I started with some different batteries and measuring the voltages on them. Then I took a 6 volt bulb and applied the different voltages to it so they could see how bright it was. Then we applied more and more voltage to the bulb until it finally died. It took almost 20 volts from some some pretty high-current sources (a big AGM lead-acid battery and a pack of NiMH rechargeables), but it finally burned out. Then we talked a little about what's inside the light bulb that burned out. One of the kids even beat me to it and told everyone else that there's no air inside the bulb. Then I did the demo that I was worried about. My big lead-acid battery, jumper cables, and some steel wire. I knew I should have put down some foil or something to catch the hot wire, but I didn't. The wire burned to a crisp immediately and fell right on the table-top, melting a nice line into the new table. Did you know that light-colored Formica table-tops have only a thin layer of light material over a dark base? I do now.

Then I went on to talk about different conductors and resistance. The big demo there was dropping some clip leads into a cup of water and adding salt until the light bulb lit. It started sort of cool for the kids, especially since they'd played with chemistry the week before. But then they got a bonus electro-chemistry demonstration as the tin plating dissolved from the anode alligator clip and the water turned an "awesome!" brown color accompanied by a steady stream of bubbles. I knew I'd get a little of that, but I didn't think it would be that much. They thought it was cool.

Then my big finale was passing out little LED keychain lights (RadioShack clearance). We had a little talk about being responsible with lights and electricity, then it was time to go.

We had a somewhat disappointing attendance this week and might have even had a few less kids than the week before. But looking around the room, I could tell that we had a lot of different kids this week than we had last week. Something I've learned is that there's no good way to predict or even understand attendance fluctuations like that. Sometimes we just have a "down" night where even a lot of the regulars miss, and we usually can't explain it.

I'm pretty excited about the future of Detour. We keep hearing great comments from kids and parents and people keep coming up with good ideas for 4-week workshop topics for kids. We've got some really great ones lined up for later in the year, especially in the spring when more teachers can make the commitment.
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