Leon Trimble

Audiovisual Artist

Leon Trimble is a digital artist who works in audio-visual performance. He specialises in immersive video and synth design. Leon is working with Professor Andreas Freise at the University of Birmingham to develop his “Gravity Synth”, which is based on the Michelson Interferometer used to detect gravitational waves (ripples in space-time) and creates musical performances. This has been, not only in terms of research, signal flow or simply even of construction, a parallel journey for both in terms of how science takes a subject and turns it into data and then relates it to a wider public, and how art does a similar thing for an audience, with a concept and a medium.

Gravitational waves are ancient messengers from the cosmos, they travel across the universe as echoes of violent events in the distant past. These waves are neither sound nor light but something completely different. Gravitational waves are described as ripples in the fabric of space and time itself, and until recently humans had no means of sensing these. After decades of development several km-scale scientific instruments can record a passing gravitational wave, and the first such measurement was awarded the Nobel Prize in Physics in 2017. However, this is just the beginning! The new instruments are becoming observatories that produce completely new information for astronomy and astrophysics. Observatories are now regularly finding and recording gravitational waves, most often from colliding black holes. The type of the black holes and their location in the sky is recognized by the strength and the exact shape of the signal recorded.

The new observatories such as LIGO and Virgo use km-long laser beams, so called Michelson interferometers, to measure gravitational disturbances. Gravitational waves are not sound and we cannot hear them. However, once recorded into an electrical signal they look very similar to an audio recording. They are signal with frequencies between 10 Hz and 10 kHz, and our ears are very sensitivity to signals of such kind. Therefore audio amplifiers and headphones are often used to fine tune and debug systems. The “Gravity Synth” plays with a similar concept, using a small Michelson interferometer that turns nearby vibrations into sound.

The Gravity Synth is a musical instrument coupling a modular synthesiser with a Michelson laser interferometer. Modular synthesisers let the user add and remove elements of the sound making process and connect them together using patch cords then send control control voltages, allowing for immediate redesign of signal flow and sound design. A Michelson interferometer is a scientific instrument to measure vibrations, by splitting a laser into two beams at right angles to each other, which are then reflected and recombined by mirrors, into an optical sensor where they cancel each other (destructive interference). When one of the mirrors, under the tension of a spring, vibrates (with local forces, i.e. the whole device, or the table it is on), there is constructive interference and the sensor receives a reading and outputs a signal. The modular synthesiser both gives the vibrations, via a solenoid that receives rhythmic pulses from a sequencer and also receives the signal from the interferometer, where it is resonated and pitch is added from a control voltage keyboard or sequence, and music is made. Further sounds, rhythms, sequences and effects are added to make a musical performance.

The Gravity Synth was recently played on the Digital Planet BBC Radio show to 4m listeners!

An album of music is available on Bandcamp - The Gravity Synth EP featuring the sound of the ifo, and MoonBounce Band recordings from inside the KTH ReaktorHallen: