Lux Aeterna


Size: outside h: 4 m - inside h: 52 cm  - ø: 13.8 m


Technique: 397 stainless steel poles 397 poly-carbonate diffusers custom tailored electronics generative software



Lux Aeterna is the official memorial for the explosion of the AZF factory in Toulouse, France. The disaster took place on 21 September 2001, and is one of the most significant industrial accidents of its time, due to the magnitude of damage and the number of victims.

The basic shape of the integration is a cylinder of fourteen meter diameter materialized by 397 fine steel poles, each with a maximum height of 4 meters. The distribution of the poles establishes the rule of 60 cm outdistance between each. The implementation was subject to a parametric program to calculate the optimal distribution of the poles, where 60cm corresponds to the minimum distance to allow accessibility, in conjunction with optical effects (moiré) derived from the superposition of 397 poles.


The memorial is located on the backside of the former industrial area, at the precise location of the exploded AZF plant. From the entrance, the cylindrical volume appears closed due to the perspective effect of the offset poles. While approaching the memorial, moiré effects occur, and the volume gradually opens to the visitor’s vision. The poles are cut to different heights and angles, becoming shorter and more horizontal as they progress towards the center of the volume. As a result, a visitor who enters the memorial has a feeling of increasing openness, as if he would be at the center of a crater.


During daytime, each pole emits a sound, a note that is part of a predetermined harmony. These harmonies change over time, randomly selected from a set of forty. The three to five notes constituting one of these harmonies are randomly distributed over the field of poles and the quantum of each is random too. Their rapid change in position and quantity results in spatial sound effects and notes taking dominance above others, causing interference and beat tones, in between the other sounds. The transition from one sound to another is done by glissando, adding further disturbance to the sound field. The very low sounds are amplified by the resonance of the poles, depending on their length, and the sum of the 397 speakers, creating a space with blurred boundaries, offering ’isolation‘ in a noisy environment.


At night, the poles light up white or red. Geometric and random illumination patterns succeed each other. The device’s capacity for the dimming of lights, allows light to change in a very soft or very rough manner, creating afterglow effects and disturbances in the spectator’s vision. Sound and light create an immaterial space while offering a physical and immersive experience. This relation between the immaterial and physical is further formalised by the poles which give the impression of a solid, but is paradoxically penetrable. Rather than being a literal representation of symbolic interpretation, the memorial is a ‘particular’ spatial experience shaped by visual and sound perception, an open field of interpretations. 


Lux Aeterna is a collaboration with the French artist Gilles Conan.