Photon Voice creates a 94 million mile long transmission line between the sun and the Mojave Desert.
Photon Voice
Photon Voice is a site-specific environmental art installation funded by the National Endowment for the Arts. Part of the large scale collaborative Inter-Arts project Desert Sun | Desert Moon, with artists Otto Piene, Elizabeth Goldring, and Lowry Burgess, Photon Voice was installed and performed in a remote section of California's Mojave Desert.
Filmed by Smithsonian World Television as a part of their long running PBS series on history, creativity and innovation in the United States, the project was included in an episode dedicated to the emerging intersection of art, science and technology. First aired in June, 1987 the program also included arts pioneer Laurie Anderson and scientific luminaries Jospeh Weizenbaum and Marvin MInsky. The program was subsequently translated into numerous languages and broadcast in the U.S, Europe and South America regularly through the 1990's.
Photon Voice, was created by Shawn Brixey in collaboration with the Laura Knott Dance Company, Boston, MA. The installation was designed around a light encoding and transmission installation integrated with choreography and dance performance. The project was designed to encode sound, images, and motion into sunlight, then decode the performance transmission by a novel receiving device sensitive to radiation pressure (the kinetic momentum of photon's). The project's primary installation system used sun tracking heliostat arrays (dynamic sun-tracking mirrors) to collect and reflect intense sunlight to a receiving station 50 yards away.
Built with a ruggedness and modularity common in space exploration, the project's receiving station combined a massive Fresnel lens, a series of condensing lenses and a 250ml evacuated sphere at its focal point filled with a minute quantity of graphite particles. Nearby photonic and electronic systems were designed to listen to the scatter light from the graphite particles and decode sound created by modulated sunlight during the performance.
Photon's have no mass but can impart their kinetic momentum to objects they strike. They can impart twice the force if the object is highly reflective (like a graphite particle). One square mile of sunlight in a cloudless desert sky exerts about 2500 to 3000 grams (or around six pounds) of pressure on the surface of the Earth. If that portion of the Earth were highly reflective like a mirror, that number would double making the sun exert approximately 10 to 12 pounds of radiation pressure.
Photon Voice's heliostats transmitted around 4/1,000,000th of a pound of radiation pressure (or 0.002 of a gram) to the receiving station. With the weight of the graphite particles being so small and the force of the radiation pressure in a vacuum (with no radiometric forces applied) so intense, the sunlight is stronger than the local effect of gravity and creates a artificial-gravitational like field for the particles to move in.
During the performance, the sun-tracking mirrors would transmit sunlight to the receiving station where the graphite particles freed from their Van der Waals forces by a powerful ultrasonic shock would begin to levitate. Once in the freedom of the sunlight they would form a flat oblate disk, much the way one imagines a galaxy or solar system forming. Once trapped in the light, the "radiation pressure" cause each particles to spin like a planet on a unique axis.
Like threading a needle 94 million miles from the sun to the earth, and then farther down into a tiny sphere, the modulated sunlight created by the dancer moving through multiple beams of variable intensity radiation pressure constructs at a distance a full 3-dimensional force field in real time, carving microscopic sculptural forms in a vacuum at the scale of just the interaction of photon's with electrons in matter