Design Process
We decided on using the Atrium, as it had a projector and metal rig that black drapes could be hung from. Another advantage to using the atrium was the four speakers we could connect to through the house audio system. This decision allowed us to make basic layout diagrams: the first shows lose-up of the central planet and moons, the second zooms out, showing the three drapes and two projectors, and the third featuring side projectors.
Based on our research into planet types, we chose to design a gas giant, a metal orb and a molten lava planet. Each planet would sit on top of a light fastened to a set of 3D printed wheels. Caitlin and Yannis also built need tracks to keep each planet still when it was not being moved by and audience member.
Technology: Data Flow
We want the representation of these celestial movements to go beyond just a soundscape. It should also reflect the natural gravitational pull between the Sun and the Moon. Through our interactive music system, we aim to let the audience intuitively feel the tension and fluctuations of gravitational forces, translating these cosmic interactions into an immersive auditory experience.
Our final solution was to connect the ultrasonic sensor using M5StickC Plus. VCC, GND, and SIG pins of the Grove ultrasonic sensor, which transmit the data to 5V, GND, and GPIO 26 of the M5StickC Plus, respectively. The computer connects to each stick via UDP protocol, and a Python script written by Lulu turns the data into OSC compliant data, and then transmits it to the Max/MSP patch.
Within MAX we calculate the tidal forces generated by the audience’s adjustments to the positions of the Sun and Moon. The tidal force is determined using the following formula:
Ft = 2GMR / d3
Where Ft is the tidal force, G is the gravitational constant, M is the mass of the orb, R is the radius of the Earth, and d is the distance of the orb to the Earth. We map these tidal forces to various dimensions: the volume of the atmosphere for each orb increases as distance decreases, wave sounds are triggered based on the rate of change of the distance of any orb, and the resultant gravitational force and vector are calculated for the musical generation side of the MAX patch.
Summary notes by Fraser David Macdonald.

