So this was not supposed to be pendulum week. This was going to be the week we explored the old borax-white glue goop concoction, but in the process of making a batch involving our last 2 full gallons of glue I guess I got overly enthusiastic with the borax, because the final product was just one big solid rubbery mass. The Pre-3 class tried playing with it on Tuesday, but since it really didn't do anything other than crumble like a giant, overcooked hard boiled egg, I had to think fast.
Good thing pendulums are such simple apparatuses to manufacture. I quickly threw together a PVC pipe pendulum machine, which involves hanging tennis balls from strings and using them to try to knock down block buildings.
We also got out my old Skittle Bowl set (the version this links too isn't nearly as cool as mine, but it's similar) one with which I logged hundreds of hours as a boy trying to perfect the technique of swinging the small wooden ball around the pivot to knock down the ten pins.
If I'd put as much time into real bowling I'd be a professional today.
But the centerpiece pendulum was a foam ball hung from the ceiling with a piece of rope. The idea, like with the "pendulum machine" is to knock down a block construction, but with the added challenge of having to swing it around the construction pylon.
This year's impromptu innovation was the introduction of a box upon which the kids could stand, and from which they could launch the pendulum when it was their turn.
Without the box, the tendency is for the kids to gradually creep closer and closer to their target until they are essentially just whacking the block buildings with a ball on a string. Yes, an adult could be stationed there to harp on them about where to stand ("Behind the line," "Go back 3 steps . . . one more," etc.), but the box is a sort of autopilot way to keep them at a distance from which they can explore the motion of a pendulum. It's always nice to find ways to avoid bossing the kids around.
For most of the children, the first attempt resulted in a direct hit on the construction pylon, but as they became familiar with the predictable motion of a ball hanging from a rope, they were all able to figure out how to hit their target. The pendulum is a more complex thing than is at first apparent to our adult perceptions.
We also learned quite a bit about construction, discovering that it is possible to build things that were too solid to be knocked down by a mere foam ball. Much more satisfying were those built with spindly bases and heavy tops.
Although those kinds of buildings are particularly difficult to build when in a hurry and in cooperation with several other little bodies jostling and clamoring to add "just one more."
More than one building fell long before the foam ball got to it because the intentional precariousness went a little too far.
This was a hard session to photograph, what with all the motion, the perspectives
and the light, but I love how this photo tells the story. The builders are being backed
off as the ball approaches, but it's too late, the building is already succumbing to
I really enjoyed how this game went under the guidance of Sylvia's mom Toby. In many ways the science of the pendulum was secondary to the practice the kids were getting in cooperative play: taking turns, building together, choosing roles, resolving minor conflicts.
And now to place that order for 2 more gallons of glue . . .