“I wonder if I can buy 7/16” balls?”
I put a finger in my book and rolled over to look at my husband, who had a dreamy, far-off look on his face. “What’s wrong with the ones you’ve got?”
Our conversation has been filled with these sorts of jokes, and worse, in the past week because John has found a new hobby: kinetic sculpture.
On basic principle, kinetic sculpture tends to take the form of Rube Goldberg-esque constructions that move various bits and pieces about in interesting ways. The idea is to move these bits by putting as little energy into the system as possible. The simplest and most common form is rolling ball sculpture—more sophisticated iterations of the plastic tubes and ramps that we would stick together to roll marbles through as kids.
If you look for kinetic sculpture on youtube, you’ll find a wide range of fascinating videos on different types of art in motion. My favorite is the work of Theo Jansen, who creates strangely lifelike sculpture that use simple counters and sensors to make “intelligent” decisions. Here’s a video of some of his stuff—I’ve only watched it silently, so I make no promises about what the audio says: http://www.youtube.com/watch?v=WcR7U2tuNoY.
John has been fascinated by the sculpture of movement for a long time, from what I can gather, but in the past week, his fascination has taken wings. Using AutoCad and parts specs from McMaster-Carr (his “one-stop kinetic sculpture shop”), he is happily planning out fantastical ways to move small steel balls. He frequently pauses in the middle of a thought to say things like: “Wait…I wonder if I could? Hmm…Now how would that work?”
When I manage to get the idea in question out of him and into the conversation, I have to admit that I get interested too. One of my classes involves a teaching technique called “critical exploration.” This is the technique the mirror exploration stemmed from, and that one exploration has me looking at everything around me as potential experimental evidence of the way the physical world works. Kinetic sculpture, as I listen to John talk about his ideas, is becoming a fascinating mode of exploration for me–in no small part because the problems that need to be solved to create cool kinetic sculpture are the fundamental questions of Newtonian physics.
As simply as Newton’s laws are presented in high school and earlier, I have had in my head for a very long time the idea that “for every action, there is an equal and opposite reaction.” I thought I knew what this meant, until the mirror question came along. Playing with this puzzle, I discovered that light leaves the mirror at the equal and opposite angle of the angle by which it enters the mirror. I thought this was a light thing, or perhaps a mirror thing, but as John and I were discussing one kink of his sculpture, I had an epiphany: equal and opposite angles? That’s not a light thing or a mirror thing—it’s a Newtonian physics thing! The rule governing why we can see what we see in mirrors is Newton’s old familiar law.
I had a moment of feeling ripped off—I had gone through all that work to figure out a rule I already knew. Then I realized that if I had really known and understood the law, the mirror question would have posed no challenge to me. And then I realized that I had rediscovered what Newton had discovered, which left me feeling both a bit cocky and a bit humbled to realize the law probably has a thousand other implications I will never recognize in my lifetime.
The bottom line is that between John’s planning and my confused fascination with physics, kinetic sculpture is likely to become a very serious obsession in the Walshe household. Just as soon as we can afford a few square feet for a workshop…