On Saturday of last week, I spent a few hours at the Exploratorium museum in the Palace of Fine Arts, near the Presidio in San Francisco. That really wasn’t enough, and I saw a bunch of cool stuff, but what really struck me was the chaos and the order.
First, the chaotic pendulum. This was a bunch of swinging arms and joints embedded into the interior of a big spinning wheel. When you spun the wheel, all the pendulums started off swinging in the same direction, but they don’t all spin with the same frequency or energy, so they start to throw each other off and get the larger wheel kicking and jerking back and forth. Fun to watch, but also a good lesson to learn about anything complex in the world.
Second, the balancing pendulum. This was one weight on a long rigid swinging arm, connected to a computer motor that could move back and forth. The computer could read the position of the arm and was programmed to get the arm balanced straight up as quickly as possible and keep it that way. It was fun to see the computer in action – choosing its moment to swing into action, going back and forth to build energy if the pendulum wasn’t swinging up all the way, and nudging carefully along if you tried to push the arm to the side by yourself.