Cosmic Rain

Mala Gallery (Bank of Slovenia)
24 May 2020 – 19 June 2021

Muons are high-energy elementary particles forming in the atmosphere’s upper layers during collisions of cosmic rays from space. They pass through our bodies, large natural masses, and human infrastructure at any given time, disintegrating mostly in the Earth’s depths.

These imperceptible particles are addressed and materialised by the light-sound installation Cosmic Rain by the artist Tilen Sepič. The installation consists of seven detector-signal units that are spread across the gallery and simultaneously powered by an electrified steel mesh.

Each individual element is comprised of a scintillation detector designed in accordance with the Cosmic Watch* open-access and open-source muon detector. As the muon passes through the scintillator, a weak light pulse is generated which is amplified by a silicon photomultiplier and then converted into an electrical signal. The built-in microcontroller detects the said signal, triggering a bright flash and a blow of the electromagnetic actuator against the mesh, emulating the sound of strings.

The distinctly material representation of cosmic particles in the form of light and sound stimuli grants the spectator a sensual experience of physical and cosmic events that are otherwise unfolding everywhere around us yet remain inaccessible to our senses. The functionalist and engineeringly-precise artistic gesture is spreading out the detector and signal network in the space, which exposes the mass of muons’ continuous collisions that are actually already present in every gallery as a kind of invisible cosmic constant of “from world separated” white and black cubes.

*The technology for these kinds of measurements has long been unavailable outside the laboratory and research-institutional context. In 2017, MIT published the plans for the Cosmic Watch Muon Detector as the first ever open-access free hardware, developed by professors and doctoral students at the MIT, WiPAC (USA) and NCBJ (PL) institutes as an upgrade of IceCube neutrino observatory in Antarctica.

-Lightning Guerilla Festival – 24 May–19 June 2021
-Tilen Sepič: Cosmic Rain | solo exhibition | 19 December 2020 – 8 January 2021 |osmo/za
-konS modul @ MFRU | 24. 11. 2020 | talk & presentation
-Is it working? International festival of art, science and technology | 24 – 28 August 2020 | Ljubljana, SI


Artist: Tilen Sepič
Circuits development and programming: Luka Frelih, Staš Vrenko, Brane Ždralo
Artistic direction and text: Maja Burja
Technical support: Luka Bernetič, Valter Udovičić
Acknowledgment: Jožef Stefan Institute (Prof. Dr. Peter Križan, Dr. Andrej Gorišek), Dadamachines (Johannes Lohbihler), Miro Križman
Text translation: Žan Korošec


Project production: Ljudmila Art and Science Laboratory and Projekt Atol

Project development within konS – Platform for Contemporary Investigative Art.

Partners #konS: Kersnikova, Aksioma, Projekt Atol, Cona Zavod, @ LJUDMILA, MKC Maribor, LokalPatriot, Univerza v Novi Gorici / University of Nova Gorica / University of Nova Gorica, Mc Velenje.

Project konS – Platform for Contemporary Investigative Art is a project chosen on the public call for the selection of the operations “Network of Investigative Art and Culture Centres”. The investment is co-financed by the Republic of Slovenia and by the European Regional Development Fund of the European Union.


Tilen Sepič (1984)  is a multidisciplinary artist and designer working in the fields of new media, light art, design of lighting objects, and audio-visual light installations. In his work he supports the open-source and DIY culture. With light-sound kinetic installations and light-based products he regularly participates in light festivals and exhibitions, both home and abroad: Vinterljus Festival of Lights (Linkoping, SE, 2019), IZIS (Portorož, 2019), Ventura Future (Italy, 2019), Responsive 2019 (Canada, 2019), Interference Tunis Light Art Project (Tunis, 2018), Design without borders (Budapest, 2018), Centre for Creativity (Maribor, 2018), Collumina Light Art Project and EVI Lichtungen Light Festival (Köln and Hildesheim, Germany, 2018), Visualia (Pulj, HR, 2017), Bella Skyway (Poland, 2015, 2016), Lumina Festival (Portugal, 2013, 2015, 2016), Lighting Guerrilla (2013, 2014, 2019, 2o21).

Tilen Sepič