It sounds good!

Both the atmosphere and we ourselves are hit by hundreds of particles every second and yet nobody has ever heard a sound coming from these processes. Like cosmic rays, particles interacting inside the detectors at the LHC do not make any noise…unless you've decided to use the ‘sonification’ technique, in which case you might even hear the Higgs boson sound like music.

A group of particle physicists, composers, software developers and artists recently got involved in the ‘LHC sound’ project to make the particles at the LHC produce music. Yes…music! The ‘sonification’ technique converts data into sound. “In this way, if you implement the right software you can get really nice music out of the particle tracks”, says Lily Asquith, a member of the ATLAS collaboration and one of the initiators of the project.

The ‘LHC sound’ project started in January 2010 and was supported by the UK Science and Technology Facilities Council. The big LHC detectors are able to reconstruct the tracks of particles and calculate how much energy they leave along their path. “In our case, some of the data coming from the ATLAS detector is collected into a file, which is then read by compositional software that transforms it into music”, explains Lily.

The sound samples currently available for listening on the ‘LHC sound’ site are made from both real and simulated data. “You can listen to the decay of a Higgs boson in the ATLAS detector, or to a proton-proton collision inside the LHC”, says Lily. “We plan to add other sounds soon such as a kind of sweet-sounding alarm system to alert people to unusual event rates and we’ve started to think about the sonification of Feynman diagrams, the drawings which describe every possible interaction that can take place at the very smallest scale. We are currently developing a new website, iPhone applications and real-data ringtones for mobile phones. Our long-term aim is to produce Graphical User Interfaces (GUIs) such that people can easily manipulate the sounds generated by the data without losing the underlying information it contains. The visual analogy to this is an event display such the one developed by the ATLAS collaboration, and the hope is that the two approaches might complement one another.”

The ‘LHC sound’ is not the only project implementing the data sonification technique. Mickey Hart, percussionist with the band Grateful Dead and a Grammy Award winner, has produced ‘Rhythms of the Universe’, a composition based on astrophysical data. “NASA is also using sonification to listen to the sun and has made sonifications of the planets in the past”, adds Lily. “Further examples include the sonification of seismic (earthquake and volcano) data developed by Domenico Vicinanza and his colleagues in Cambridge (UK)”. And she concludes: “Making particles produce music is a way to get people interested in the results of the LHC experiments in a way that is novel, exciting and accessible. This allows us to share the excitement of being part of this great enterprise with a wider audience”.

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