Sound for this installation originates from space. It has been collected/recorded as data for space research and Earth observational science and transformed into a multi channel audio composition for Trajectory. There are two main sources: Chorus & the Sun
Chorus [playing on 4-6 speakers - depending on installation space] originates from data collected by the Cluster II satellite on the 9th of July 2001 (see diagram above) using a Long Wave Radio receiver. Through a process of transposition and filtering the signals (which fall outside the range of human hearing), the data becomes audible.
Chorus consists of brief, rising-frequency tones that sound like the chorus of birds singing at sunrise, hence the name "chorus" or "dawn chorus". Chorus at Earth is generated by electrons in Earth's Van Allen radiation belts. Once generated, the chorus waves affect the motions of the electrons through a process called a wave-particle interaction. Wave-particle interactions disturb the trajectories of the radiation belt electrons and cause the electrons to hit the upper atmosphere.
Chorus has been composed by shaping, filtering (removing unwanted frequencies to reveal the detail and texture of others) and spatially placing each sound within a multi speaker diffusion system to recreate the spatial qualities of the Earth Chorus within the gallery space. Although it has been composed and therefore treated within a musical structure, Chorus remains a true record of the original data.
Sun [playing on 2 of the 6 speakers – depending on installation space] comprises a mix of low frequency pulsing drones created with recordings of bubbles forming within the Sun (see details below). Sounds have been looped and filtered to create an underlying deep texture providing contrast with the higher frequency Chorus. The audio has been synchronized with the images playing on the sun projection screen which features a audio spectrum of the sound of solar flares – where this appears recordings of the solar flares have been used to support the image, providing both audio and visual information.
Sound from the Sun
Deep within the sun, in the swirling cauldron of hot plasma called the convection zone there are bubbles rather like the ones in boiling water. These, like the ones in water, create a noise. As they reach the surface these bubbles of sound squeeze the plasma so it gets brighter in places whilst at the same time moving upwards. By measuring this upward and downward movement the instruments onboard the Soho Space Craft have been able to record this as sound. Naturally the sound creates a very low frequency as movements occur once every five minutes but by recording this and accelerating it 42,000 times 40 days of recording can be compressed to create a few seconds of audio. (Source: ESA)
|Trajectory of Cluster II|