## Global choreography

Another fascinating aspect of this global network of antennas is that they will move together in groups. Several antennas will rotate to point simultaneously towards the same quasar, they will measure for a brief period (maybe one minute or so) and move on to measure another quasar. For some antennas the quasar might be below the horizon and they will be unable to participate in that particular measurement.

Several such groups of antennas will be simultaneously active, and they will continuously be regrouped into different subnets according to quasar visibility. Also, some older or bigger antennas may only be able to move very slowly, so the small and quick antennas will perhaps dart off in another direction to make another quick measurement while the big ones trudge on to their next collective measurement. All this together makes for a global choreography of the antennas, with simultaneous movement and/or counterpoint movement in different subgroups of variable sizes.

To take this choreography and make sound from it, I’ve projected the quasar positions on the surface of the earth (by drawing a normal) and registered which subnet of antennas are observing this quasar at any given time. I’ve simply mapped latitude to pitch and longitude to pan position (12-channel in the physical installation and 2-channel in the online stream). The reason for this simple mapping is that I think it may make it possible to intuitively relate the positions on a map to the sound of each point (up on the map is a brighter pitch, down on the map is a lower pitch, east on the map makes a sound to the right, and west on the map a sound to the left). I’ve made two different versions of the global choreography sound, one which simply traces the positions and includes all positions of a quasar. These positions will “drag” along the surface of the earth as earth rotates in relation to the quasar position and this will create an iterative vibrating sound which slowly changes its properties. I think the resulting sound has something in common with a mouth harp (for some reason ….
I did not actually plan this, but I do like it):

In another version of the sound, I’ve removed the repeated measurements of the same quasar, so that each observation only get a single sound event. Here, I’ve given each subnet of antennas a different timbre, so that it should be possible to differentiate them in the resulting sound, although the relationship is not as simple and intuitive as that of lat/long and pitch/pan. This creates a more open sound that perhaps more clearly represents the movements of the choreography: