Tuesday, September 23, 2008

Second Science Class for Elementary

I just finished up the second science class.

First, we reviewed what we went over last week about what science is and where it started and why it started there.

Then I introduced our topic for this week: Thales (thay-leez). We discussed Thales as the first scientific thinker. We discussed that the Ancient Greeks before Thales would explain earthquakes as caused by gods. Thales thought the Earth might be over top of water and the motion of the water would cause earthquakes. Another of Thales thoughts that was that all things were water (to be picky it's hard to tell if he thought all things started with water if all things were made with water).

Both of those ideas are wrong, but it the ideas were important for a number of reasons. Thales was working with what he noticed around him. He was trying to explain what he observed. But he wasn't just explaining the particular instances he observed, he was generalizing his ideas to include all such events (every earthquake, not just the one in Greece last year). The ideas are also important because they were natural explanations--not relying on gods.

Here's what I wrote on the board:
  • Thales ~600 BC
  • First Natural Explanations
  • Observations
  • General
I then spoke about some of the other things attributed to Thales. Another accomplishment was that Thales could measure tall buildings and also tell how far away ships were. It was written that Thales predicted a solar eclipse. I told the story about the shepherd boy in Magnesia whose staff was sticking to a stone, but the stone wasn't sticky. It was only the metal tip of his staff that seemed to stick, nothing else. Thales was supposed to have examined the stone's behavior.

I brought out my loadstone sample (my $3 specimen that isn't actually magnetic) and the kids could observe that it had rust on it. We then switched to real magnets and filled out a chart like the following:

Attracted Not Attracted

We tested a number of materials like steel, brass, paper, plastic, wood, cork, paper clips (or we would have if I had found them), and aluminum. I let the kids keep their magnets so they could do more testing at home.

Afterward, we talked about how Thales noticed that rubbing amber allowed it to attract little bits of stuff. We tried rubbing plastic rulers with our hair, but that didn't work as well as the balloons. The kids ripped up paper into little squares and then were able to use the balloons to pick it up after rubbing the balloons on their hair. They also got the balloons to stick to the walls (who hasn't done that?), attract the cloth of the tablecloth, stick their skin, and pick up bits of yucky stuff from the floor near the baseboard (where your vacuum will miss). I pointed out that magnets attract only specific things but that the balloons seemed to attract everything.

At the end, I decided to review 45 degree right angle triangles (I may decide to talk about how Thales may have measured buildings' heights by measuring its shadow at the time of day when the shadow and the object make a 45 degree right triangle). I also reviewed circles, ellipses (how a circle at an angle would be foreshortened), cylinders (if the Earth only curved in one direction), spheres, hemispheres (hmm--not sure I really had a reason to introduce this--perhaps I'll remember later), and squares and cubes (if a square were stretched in height) to prepare for area and volume discussions.

In order to get the kids to understand the importance of angle (let's not forget that I'm spanning 1st grade to 4th grade in this class), I held up a square and asked them what the shape was. After they all said square, I asked how they knew. The answer was, of course, four equal sides. I drew a rhombus on the board (a parallelogram with four equal sides, a diamond) and asked them if that was a square. They all answered no and I asked why not? Why was one shape with four equal sides a square and the other wasn't? One of the kids (who's advanced in math) knew that squares have perpendicular sides that make a right angle. I also showed three different size 45 degree right triangles and pointed out that as one side got longer, the other side got longer by the same amount and because a 45 degree right triangle is half a square, the kids know the two straight sides have to be equal in length.

At this point, I'm not going into the explanations, just doing the same type of exploration that Thales may have done. I didn't bother giving the kids the other explanations the Greeks came up with to explain the behavior. I may choose to go into that when I switch from a purely historical presentation to a presentation for each discipline (after the ancients). Most of what I tell the kids is generalized and I am not trying to present the entire picture--just enough to get us going. I know some of the details are being questioned at this point (like the solar eclipse prediction), but the kids can worry about that if they ever become historians.

Our next class (or two) will discuss some of the cosmologies of the Ancient Greeks. I'll be presenting evidence that the world curves and the ideas of the heavens moving around us. I'll also quickly present Empedocles idea of the four elements and their forces. Then I need to present Aristotle's reliance on observation over another's conclusion (if I can find it). Once those thing are out of the way, I'm all about Archimedes.


LB said...

That sounds really, really good, Kim. You're helping them make connections that most science programs skip over resulting in a bunch of floating, unrelated ideas.

The tough part is almost over and then it's fun with Archimedes! Have you read the Archimedes and the Door of Science book for kids? Did you like it?

Thanks again for sharing and keeping us updated. Maybe you can put it all together and give a mini-workshop on it in the summer. I'd pay to go.

Kim said...

I did read Archimedes and the Door of Science (in fact, I lost it after checking it out of the library and STILL can't use my library card because I have to pay for it). I liked it OK. I think it was interesting, but I was close to being done with historical stuff and needed more about the science. So this was a month ago now, so I think I liked the book but that there was something that bugged me about it--but I can't remember if it was me wanting more science or being disappointed that I could only find a book on Archimedes, not anyone else. Hmm...wish I could remember. It may have been that I had already done enough research that the book didn't add a lot.

I am hoping to put enough information on the blog for me to refer to again and also so that anyone else could use it too.

So far, I think it seems simplistic for the kid who has already done a lot of scientific exploration and reading. I hope that we'll get to something that is simultaneously more formal and more in-depth and with more understanding than other things that child has done. The other kids are enjoying it (even the littlest). I try to include some rowdy behavior to keep up the fun level and interest. It's nice that the kids stayed to play afterward as well.

I was thinking about doing a high school level course (way more fun because you can go fast and not worry about a lot of the math) but wouldn't most people just go to a community college for that?