The sound in the attic is made possible by the students from Ilford County High School who collaborated on the Cosmic Ray Project. Without their expertise and generous help the project could not have happened.
Collaborators: Surya Ragavan, Paul Balaji, Josh Kandola, Guy Coop, Suraj Patel and team leader Vikash Patel.
The school has three scintillator detectors housed in boxes in the grounds which were installed by the head of Physics, Dr Paul Edmundson. The detectors form part of  the UK wide project COsmic Rays in UK Schools (CORUS). The detectors used are on loan from King’s College London and the University of Alberta, Canada. The CORUS project involves the participation of schools and many of the county’s leading universities including King’s College London, Leeds, Durham, Sheffield, Manchester, Edinburgh and of course Bristol.
 
After planning strategy and assigning tasks, the team started by writing formulae to represent the value and character of the detected cosmic rays in relation to their energy. The fomulae used were based on the Bethe-Bloch formula and the Landau distribution. These formulae are in units of energy and were converted to frequency using the well known Planck equation E=hf (E= energy, h= Planck constant, f = frequency) to be used in the sonification. They wrote their own programs to handle and organise the data including designing code to represent the strength, duration and direction of the cosmic rays hitting the detectors from different parts of the sky.
Their midi data illustrates the cosmic rays that are translated to audio files and heard in the attic here in Bristol as sound.
It might surprise you, but as you read this you are being bombarded by sub-atomic particles (about 5 per second through the top of your head!). Further, you have spent your entire life with these particles streaming through you with the occasional one being absorbed by the cells in your body. They are actually produced in the Earth’s atmosphere by cosmic rays – high-energy particles which start out life in deep space. Closer to home, they have almost certainly had a role to play in human evolution and the origin of life, may cause lightning and have recently (and controversially) been implicated in climate change.
For scientists, cosmic rays are important as part of the energy balance of the Universe and in understanding the evolution of its building blocks. High energy cosmic rays like those sonified at the exhibition are thought to come from some of the most violent places in the Universe, jets of material launched from super massive black holes and the remains of supernova explosions being two of the prime candidates.
Cosmic rays are mainly protons (hydrogen nuclei or alpha particles (helium nuclei) but also contain larger particles, for example iron. When these high energy primary particles interact with atoms in the atmosphere they produce a shower of secondary particles often containing exotic matter usually only found in particle accelerators such as the Large Hadron Collider (LHC) at CERN. These secondary particles themselves either decay or interact to produce yet more particles and so an initial single primary particle produces a shower of secondary particles, spreading downwards in a cone with a width depending on the energy of the primary particle. By the time the shower reaches the surface of the Earth, most particles have decayed to produce muons – a heavier version of an electron. It is the muon flux detected at Ilford County High School which has been converted to sounds.