Pendulum light, 2004, work in progress

“ Pendulum light” is an interactive installation conceptualized by Takehito Etani for an exhibition at a vacant space in Liberty Avenue, downtown Pittsburgh. The project is a part of Fabian Winkler’s Responsive Urban Space Class at Carnegie Mellon University, 2004.

As the visitors walk in the space, they find there is a light bulb hanging close to the floor. As the visitors approach to the light bulb, the dim light become slowly brighter and starts shacking. The oscillation of the shacking gradually becomes larger and larger and the light bulb swings back and forth in the empty space.

The light bulb also flickers in response to the footsteps and the other sound created by the visitors such as their voices. As the visitors walk away from the light, the motion of the light gradually diminishes and eventually goes back to still.

The swinging light bulb is proposed as one of the most simplistic way to energize the empty space. The movement of the light moves the shadows of the space itself and the whole space comes back into life. The viwers’ shadows casted on the walls and ceiling also moves back and forth and viewers becomes more aware of their presence and their act of viewing itself.

How it works

The swinging motion of the light bulb is controlled by the drive system installed under the ceiling from where the light bulb hangs. The drive system consists of a simple cam system that is driven by a RC servomotor. The servomotor is controlled by an OOPic microcontroller.

Finding the right speed in relevant to the length of the cable that the light bulb hangs from is the key to obtain the maximum oscillation of the pendulum. The speed of the motor is consistent. Simply rocking the top part of the cable in the adequate speed will enable the pendulum to reach the momentum after about 5 minutes. There is also light weight is attached to the bulb to counter the friction from the air.

The drive system is already realized. The interaction with the viwers’ presence and the footsteps will be achieved by a combination of a proximity sensor nd a simple vibration sensor connected to another Oopic micro controller.