Astronomer royal and physicist who greatly advanced understanding of cosmic rays
Sir Arnold Wolfendale, the 14th astronomer royal, who has died aged 93, did much to advance understanding of cosmic rays, the stream of charged particles from outer space that continuously bombard the Earth’s atmosphere. For this purpose he assembled a strong team at Durham University, making it one of Britain’s leading centres for research in this field. In 1956 he joined the physics department as a lecturer, and during his time as professor (1965-92) established a highly regarded astronomy division.
Secondary cosmic rays result from primary rays impacting on the Earth’s atmosphere. Among the secondary particles found at ground level are muons, one of the fundamental particles of the standard model of particle physics.