My seven year old commented at breakfast, that he thought he would be be able to hear his brother chewing, clear from the moon.
My answer, of course, was, "No dear, there's no atmosphere on the moon for sound waves to travel through, so you wouldn't be able to hear anything at all there."
When he gave me a blank stare in return, I knew we were in need of an experiment. This is another one (slightly modified) from Robert W. Wood's what? experiments for the young scientist, which has definitely moved to the top ten of my favorite science books list.
First, I showed him how a drop of water causes waves to move through a bowl of water.
Then, I cut a dime size hole in the lid of an empty coffee can (Woods suggest using an empty salt container, or oatmeal box).
I lit a candle in the middle of the table. After, the children had observed the candle flame for a while, so they could see it was still, and not being moved by any breezes, I had them point the hole in the coffee can at the flame, and tap the bottom of the can.
Each tap, caused the flame to move and dance, in time with the noise.
We tried tapping the can farther away from the flame, and closer to it, to get an idea of the range of the sound waves.
Finally, we watched The Magic School Bus In The Haunted House (you can watch it for free, here, on gamequarium.org) for a child friendly explanation of sound waves, and how they work.
For more fun with science, check out the Science Sunday blog hop, hosted by Adventures in Mommydom.
It's great to be a homeschooler.