Event Decoherence – Soundinstallation


10.03.2016, 19.30 Uhr
@ Trezor

Backlab Artist: Irradiation

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Irradiation – “Decoherence 1.0”
in cooperation with
Phd. Gabriela Barreto-Lemos & Phd. Mehul Malik
(IQOQI – Institute for Quantum Optics and Quantum Information, Vienna)

The System

The interference pattern (circular fringes) of a Michelson Interferometer is detected with light-to-voltage diodes. The measured voltage values control several sound-parameters of granular synthesis.
The soundwaves create changes in the fringe pattern, that in turn modulate the sound, thus creating a double-feedback mechanism between sound and light. Additionally the physical motions of people through the room create vibrations on the floor and also slight temperature fluctuations, which again influence the interference pattern and therefore the sound-parameters.

The Michelson Interferometer

A Michelson Interferometer is a common configuration for optical interferometry. A light source is directed to a semi-reflective mirror. This so-called “beamsplitter” separates the light beam into two different paths. Each of those beams is then reflected back towards the beamsplitter. When the two beams are recombined they form a typical interference pattern due to phase differences. It’s analogous to what one sees if two stones are thrown into water near each other: two sets of circular ripples that interfere when they cross each other.

The Michelson Interferometer is quite well known for two important scientific discoveries:

1. It is known for it’s use by Albert Michelson and Edward Morley in one of the most famous experiments of all time: the scientists wanted to detect the luminiferous aether, the static medium in respect to which any motion would supposedly occur. The null result of that experiment essentially disproved the existence of such an aether and at the same time obtained the speed of light in vacuum. The non existence of an absolute space was essential for the development of Einstein’s Special Theory of Relativity and the revolution in physics at the beginning of the twentieth century.

2. Recently, a huge Michelson Interferometer has gone viral, due to the first direct detection of Gravitational Waves (2016, LIGO), which were predicted by Einstein in his General Theory of Relativity (1915).


In Classical Mechanics, particles and waves are two separate things: waves can interfere, particles can’t. When such sinchronized waves are combined, they add to each other, creating a larger wave. If the waves are oscillating perfectly out of sync, they cancel each other out. This phenomenon is called interference, where coherence refers to the ability to produce an interference pattern.

In Quantum Mechanics, every particle is also a wave and all the astounding phenomena associated with Quantum Mechanics are the interference of these particles/waves. In a classical world, particles do not interfere and by definition cannot be coherent. Thus the quantum to classical boundary is also the boundary between coherence and lack of coherence for particles.

Decoherence is the crossing of this border, the loss of quantum properties and the return to a world where Schrödinger’s cat isn’t dead and alive at the same time. Decoherence provides an explanation for the observation of wave function collapse, as the quantum state of the system “dissipates” into the environment. A total superposition of the global or universal wavefunction still exists and remains coherent at the global level, but its ultimate fate remains an issue of interpretation.

In this installation, the interferometer, the music and the people in it constitute the decohering environment. It invites us to think about the nature of reality and shows how we are not just independent observers of the universe, but quantum objects that fleetingly interact with the quantum world around us.

(Irradiation, Gabriela Barreto Lemos, Mehul Malik)

is a composer, sound artist, DJ and club host as well as the co-initiator and manager of the viennese label TEMP~, founded in 2003. With it, she has published several EP’s and an album. Irradiation’s artistic output is best described as a permanent exploration of the space between repetitive and abstract, electronic music. Her latest solo releases constitute a cartography of links between electronic music and quantum theory which join the loose ends between electronic dance music and acousmatic improvisation. She has been working in several cooperations with sound- and video artists, e.g. with Chra as “Pasajera Oscura” she explores even darker spheres. One of her greatest interests lies in artistic work with science, especially (quantum)physics.

Gabriela Barreto Lemos
Is currently a senior post-doctoral fellow at the Institute for Quantum Optics and Quantum Information in Vienna, Austria. She obtained her PhD at the Federal University of Rio de Janeiro, Brazil, on decoherence caused by chaotic environments. Her undergraduate studies at the Federal University of Minas Gerais (Brazil) were in physics (major), music and philosophy (minors). Her greatest interests are in finding a dialogue between art and science and bringing the questions discussed in quantum physics to a general audience (e.g. “What if we were the size of an atom?“ – TEDxVienna 2015).

Mehul Malik
is a Marie Curie post-doctoral fellow in the group of Professor Anton Zeilinger at the Institute for Quantum Optics and Quantum Information in Vienna, Austria. Originally from New Delhi, India, Mehul received his PhD in Optics in 2013 from the University of Rochester. Before that, he studied Physics and Art at Colgate University, NY. He is currently working on creating the first multi-photon entangled states in high dimensions using twisted light. His broader interests lie in the fields of fundamental quantum optics and information, as well as in starting a conversation between science and art.