Thursday, October 7, 2010

Smooth Sailing

A couple weeks ago, we found two swallowtail caterpillars in our patch of dill. We put them in jars and fed them until they made their cocoons. We were sure, due to the lateness of the season, that they would over-winter in their cocoons. Yesterday we were surprised to see a butterfly in our jar! Apparently, it had other plans. We quickly moved the stick with the butterfly to our flower bed to allow it to prepare for its first flight. Later in the day, he (we are fairly certain this one was a male, based on coloration of wings) was gone.

In other news...we made a discovery. Not all experiment books are created equally. We have been working our way through a unit on weather and atmosphere. We generally plan to 'do' science three days a week. I also try to include at least one demonstration or experiment every week. Last week we were discussing cloud formation. I found a demonstration in one of our science books for a 'cloud in a jar' and thought, "Perfect!". was anything but perfect. This particular book recommended putting an inch of water in a jar, putting a lid on, placing it in a saucepan of water on the stove. When the water in the pot starts boiling, place a plastic bag of ice cubes on the lid of the jar and wait for a cloud to form. NO cloud. Sad kids. Grumpy mom.

So, over the weekend I searched for a better version of this demo. I knew I had one some book...(not that I have a lot of books lying around here...perish the thought!) Then I found it, Janice VanCleave's Spectacular Science Projects: Weather. Have I ever told you about my love for Janice VanCleave? My husband laughs at me when I start talking about her books because I get so caught up in my joy over the elegance of her experiments and her ability to teach science, that I literally tear up. Some women cry for sappy commercials...I cry for good science.

When I read her version of this demonstration I knew right away it would work. Put a small amount of water in a glass jar, swish it around a bit, dump most of the water out. Have an adult (important!) light a match, blow it out and hold it inside the jar for a few seconds. Immediately have a helper stretch a square piece of latex, cut from a rubber glove, over the top of the jar and seal it with a rubber band. Push down in the center of the latex. Then pull the center of the latex back up. The change in pressure, plus the presence of the smoke in the air, allows the water to condense and form a cloud in a jar! Happy kids. Happy mom. Concept grasped. Education acquired.

1 comment:

Annie said...

Re: the butterflies, I love it when learning opportunities spontaneously occur!

As for the experiments, you aren't the only one to have them fail. We had two experiments fail this weekend, although we followed the instructions. We researched them on the net, corrected the issues and got predicted results. It bothers me when they fail, but I think seeing the failures is also educational. (Or at least I'm telling myself this! :) )