Electrical symbols for ground

Video taken outside L.A. Department of Water and Power Receiving Station G in Atwater Village, during a subterreanan recording session for this program.

Alternating current is transmitted at a frequency of 60 Hz. Every node on the power grid must have a direct path to ground, thus there is electricity being routed into the ground constantly. This phenomenon is known as the mains hum. Two metal rods and some copper wire act as electrodes – stick them in the ground and the electricity present completes the circuit. Hook the electrodes up to a portable speaker and the hum reveals itself.

Tonight’s show features a survey of sound from the ground recorded all around Los Angeles.