One century of cosmic rays – A particle physicist's view

Experiments on cosmic rays and the elementary particles share a common history that dates back to the 19^th century. Following the discovery of radioactivity in the 1890s, the paths of the two fields intertwined, especially during the decades after the discovery of cosmic rays. Experiments demonstrated that the primary cosmic rays are positively charged particles, while other studies of cosmic rays revealed various new sub-atomic particles, including the first antiparticle. Techniques developed in common led to the birth of neutrino astronomy in 1987 and the first observation of a cosmic gamma-ray source by a ground-based cosmic-ray telescope in 1989.