Cosmic Ray Extremely Distributed Observatory

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is an ongoing international project aiming at searching for large scale correlations of cosmic rays. The CREDO strategy is based on operating a global network of cosmic-ray detectors of various sizes and diverse technologies in order to reach sensitivity to cosmic-ray ensembles (CRE): groups of correlated cosmic particles (inlcuding photons) that might have energies the whole energy spectrum of cosmic rays. This approach has a potential to reveal even the most fundamental properties of the Universe, including e.g. the structure of space-time or nature of dark matter. Until recently, cosmic-ray research has been focused on detecting single air showers, while the search for ensembles of cosmic-rays, which may spread over a significant fraction of the Earth surface, is a scientific terra incognita. The key idea of CREDO is to combine existing cosmic-ray detectors (large professional arrays, educational instruments, local networks, individual detectors, such as smartphones, etc.) into a worldwide network, thus enabling a global analysis.