Monday, December 19, 2011

Astronomy Unit: Refraction, Vacuum, Saturn's Rings

The kids have been begging for some hands-on science experiments. I have a bigger unit planned, but since December and January will be a bit broken up as far as our schooling goes, I decided to delve into a short unit with lots of experiments based on one of Janice VanCleave's books (202 Oozing, Bubbling, Dripping, Bouncing, Experiments) and lots of notebook/lapbook pages from Homeschool Bits. Here's some of what we've been up to so far:

1. Bent Light - Refraction
We placed a penny in two cups and poured water in one cup.  Then we put a pencil on the ground when we couldn't see the penny any more.  For all three of us we could see the penny that was in water longer than the one with air.  We talked about "refraction" and LD made a great connection to Brian in Hatchet who tried and tried to spear a fish unsuccessfully. Finally, he realized the water made the fish appear in a different spot and he was able to spear them.
We measured the distance between the pencils for the three of us.  For me it was 6 1/4 inches, for LD it was 5 1/4 inches and for DD it was 4 1/4 inches. We talked about why that was the case (the differences in our heights and the angle of our eyes to the penny).

The kids all wrote down a few key words for each science experiment to put in their science notebook.  I thought it was lovely that ED demanded a paper and wanted to write letters on her sheet as well. She was so diligent!
2. Vacuum as a Heat Shield
This experiment also led to some fascinating discussion.  We boiled some water and checked the temperature. Then we poured some of the water in a thermos and some in a cup.
Next we talked about the vacuum in space and the fact that it is very cold.
I explained to the kids that the thermos had a partial vacuum.  Then I asked the kids to predict which water would cool down more quickly.
LD predicted the thermos would cool quickly because space (the vacuum of space) is so cold.  DD predicted the water in the cup would cool more quickly.
We went on to our last experiment and came back 15 minutes later to check the temperature.  The water in the thermos was nearly the same as it was originally while the water in the cup had cooled significantly. We talked about the fact that space is a poor conductor and thus acts as a heat shield whereas metal (we felt the end of the thermometer is a good conductor, transferring heat easily).
 3. Saturn's Rings
We have gone over the planets numbers of times in our homeschooling adventures here.  Today we reviewed the planets, their locations and sizes.

We got a piece of paper with two circles on it (the inner one for the planet, the outer one for the field of debris icy particles and rocks, that encircles Saturn). They sprinkled sand evenly on the paper. Then the kids placed the end of a Popsicle stick down which represented one of Saturn's moon. I turned the tray around and we watched as the sand was pushed away. Scientists believe the moons push the icy particles around into separate bands which make the separate rings of Saturn.

Last year we did a hands-on unit on Earth Science if you want to see some of the activities we did related to that.

1 comment:

  1. We used janice van cleave's astronomy experiment book a little with our astronomy unit. We really had a lot of fun with that unit. We didn't do any of these experiments though. There's so much to learn!

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