by Panos Charitos. Published: 17 October 2013

In 2004 Chris Fabjan, former ALICE Technical Coordinator, invited ALICE members to participate in the CERN 50th anniversary celebration, proposing a stand to show at the CERN 2004 Open Day.

The ACORDE group proposed a modified version of the Musée des Arts et Metiers Cosmophone, a device which produces a sound when cosmic particles activate a cosmic ray detector. At Centre Jean Monnet in St. Genis we presented a system of four scintillator paddles, light lamps and sound speakers to produce light flashes and sound beeps, together with an electronics box. To operate the scintillator paddle PMTs, we need HV and LV power supplies. The electronics box was used to manage the analog signal produced by the PMTs and select coincident events between those scintillator paddles. That was the first primitive version of a demonstration device, used to show, in a ludic way, how we detect secondary particles coming from cosmic rays interaction with the Earth atmosphere. This apparatus has been improved over the years and exposed in several Science Feria events (Barcelona, Torino, Warsaw , Geneva, Merida, Puebla, Hermisillo, etc.)

During the 2013 CERN Open Days, the ALICE Cosmic Piano was presented to the public by members of the ALICE ACORDE group from Mexico.

These are the historical roots of the Cosmic Piano presented in the CERN Open Days 2013. This system consists of eight particle detectors (inspired by the STAR-TOF detectors used to calibrate the ALICE TOF detector with cosmic rays) with LED lamps and speakers attached. The electronics has been modified to convert the APD analog signals (two APDs inside each particle detector) into digital LVDS signals, produce music tones and light the LEDs when a detector catches a cosmic particle. The Cosmic Piano has some features like producing light and sound only when n (n= 2, 3,...8) modules are hit at the same time ( coincidence events, technically named “cosmic showers”) or generate a “random musical noise” when any of the eight detectors is impacted by a charged particle. One should acknowledge here the role of Guillermo Tejeda Muñoz who has been responsible for the electronics of the Cosmic Piano.

Rehearsing with the Cosmic Piano.

A talented young piano player!

The Cosmic Piano was presented during the 2013 CERN Open Days, offering visitors the opportunity to listen to the melody of our Universe, played by the cosmic rays that travel through the Earth's atmosphere. Professor Arturo Fernandez Tellez along with Juan Grados Luyando, Hector Bello Martînez, Luis Pérez Moreno and Abraham Villatoro, all members of the Cosmic Piano Team, were present both days, showing the Cosmic Piano to visitors and discussing with them. Thanks to their efforts it sounded like a well-tempered cosmic piano.