This morning I was sitting on the couch reading an astronomy lesson to my two girls. The general topic was “The Sun”. And one of the paragraphs was describing the movement of the planets around the sun. This movement was described as revolving or orbiting. The book went on to mention that not only was the earth revolving around the sun, but the moon was revolving around the earth; and as it revolves, it always keeps the same face towards the earth.

Then the book gave an invitation that neither I nor the girls expected: “Wouldn’t you like to try it?” it said. Immediately the girls became electrified as I continued reading how one person could be the sun, another could rotate around the sun as the earth, while at the same time a third person could revolve around the earth as the moon. Well, there was a mad scrabble for shoes, and cries of, “just a second, I’ll be right there, wait for me!”

“Oh, and by the way,” the book added, “If you are able to coordinate all the motions of these objects, then maybe you could add the rotation of the earth on its axis as it revolves around the sun.”

Out to the backyard we dashed, and the girls turned and giggled and bumped their way through their orbits and rotations; they even ended up spinning on their axes while proudly displaying a slight lean at their poles to create seasons as they revolved around the sun. The experiment quickly moved from order to disorder with the orbits becoming more and more erractic and then the objects falling out of orbit completely! I had no idea astronomy could be such fun!