The origin of cosmic rays

The subject of 'cosmic rays' is one that embraces a vast range of particle and photon energies and is an ideal one for examining 'Physics and the Cosmos'. In the present work we examine the problem of the origin of cosmic rays of all energies. We find that low cosmic ray particles and gamma rays are related by studies of the Magellanic Clouds. At higher energies it is proposed that supernova remnants are giving a characteristic cosmic ray signal. At the highest energies it is proposed that colliding galaxies are important. Also examined is the flux of extragalactic gamma rays and its relevance to the question of the asymmetry between matter and anti-matter in the Universe. (author)