'Planetary Runway' audiovisual installation for 8 speakers and 8 light diodes, 2009

This audiovisual installation consists of 8 loudspeakers that are placed on a straight line of at least 25 meters (longer distances are preferred). Next to each loudspeaker is an LED diode. A pulse sound is played through the 8 speakers and the LED diode next to each speaker flashes up in exact synch when the impulse is emitted through its associated speaker.

This installation focuses on the time that sound needs to travel, and uses this phenomenon musically. Because of the rather large distance from the first to the last speaker (at least 25 meters, preferably more), the time difference between sounds emitted through the closest and farthest speaker can well be perceived. The output of the impulses is delayed for each speaker in such a way that all 8 impulses will be heard exactly at the same time, when the listener/viewer is positioned at the position of the first speaker. Since the flashing light diodes of each speaker will be delayed exactly in the same way as the impulses, they will not light up at the same time. Because of the large difference in speed between the sound and the light (speed of light: ±300.000 km/s, speed of sound: ±0.343 km/s), the light flashes will be visible as running from the farthest position to the closest, while the pulses will arrive simultaneously at the position of the first speaker. A discrepancy will therefore be revealed between what is heard and what is seen.