Illustration of the US-Canadian astrophysicist James Peebles (born 1935). Peebles, along with Robert Dicke and others, independently predicted the existence of the cosmic background radiation and planned to seek it just before it was found by Arno Penzias and Robert Wilson. He has investigated characteristics of the radiation, clustering and superclustering of galaxies and has calculated the universal abundances of helium and other light elements, demonstrating agreement between big bang theory and observation. He has also worked on dark matter, providing evidence of the existence of large quantities in the halos of galaxies. Peebles was awarded a share of the Nobel Prize in Physics in 2019 for his wide-ranging work in cosmology along with Michel Mayor and Didier Queloz.