What Goes Around

3/18/07 – 3/24/07
by C. Zaitz

I’ve been giving a series of planetarium shows for fourth graders. I’ve heard a lot of interesting things come out of ten year olds, but today they stumped me. I was pointing out the planets that are visible in the early evening. Venus hovers above the sunset, driving light daggers into your eyes as you watch the glow of the sun fade. Saturn, however, lags behind and is only just rising to a nice height at sunset. It is in the southeast, whereas Venus is definitely following the sun into the west.

I told the fourth graders that it was 8:30 at night and I showed them the two planets. Then I asked them where Venus would be by 10pm. They were a verbal group with stretch marks in their armpits from raising their hands so much. I assumed they would say that Venus would go down in the west, like the sun, moon and all the stars. It seemed like a safe question.

Not so. Among the answers I got were, “it will go to the north,” “it will go back to the east” and “it will go south.” I could not BRIBE them to say it went down in the west. So I asked them what was really moving when the sun went down.

We talked through the rotation of the earth and I told them that we are spinning at 800 mph in Michigan. I asked them why they thought we couldn’t feel that motion and we talked about the reasons, such as the fact that we’ve always been spinning on the big earth and as long as it doesn’t speed up or stop, we will never notice its motion. Then to top it all off, I basically pirouetted until I got dizzy to illustrate the motion of the earth. That was my big wind-up. Then I threw it back to them. With excited, baited breath I asked, “So where will Venus be in an hour, my young friends?” I was sure that my antics and explanations had done the trick. But it hadn’t. Not even close. Somehow those young minds had heard or read something that had confused them about the motion of sky objects. And I didn’t know how to undo it.

So I laughed it off and we moved on. Later on the time came to actually move the stars toward the west. I took the opportunity to try once more, so I pointed to Venus and had them watch it as it sank down into the western horizon. I think they saw it. They looked surprised, but I think they finally believed that Venus would follow the sun down in the west. Sometimes seeing is believing. I know that the concept of the earth spinning is pretty abstract, and ten year olds aren’t quite abstract thinkers yet, but I thought that they might have noticed things setting in the west. When I realized they may never have actually seen Venus in the sky, I got a little sad. So to all of you with kids, take them out this month and show them Venus. Just point yourself toward the west at sunset and you’ll see it, clouds willing. And if you have a few moments later on, spy on it again and see where it went. I’m pretty sure that it will have followed the sun down in the west. But it’s always good to see it for yourself.

Until next week, my friends, enjoy the view.