Elected F.R.S. 1955
David Robert Bates was an inspirational figure in the histories of atmospheric science and of atomic, molecular and optical physics. In his researches, each discipline was informed and enriched by his insights into the other. He drew deep connections between them in a creative interplay of innovative ideas. Together with Sir Harrie Massey, F.R.S., building on the work of Sydney Chapman, F.R.S., David Bates provided the first realistic description of the physics of the terrestrial ionosphere in which the ion and electron production and loss mechanisms were identified and their efficiencies calculated. His early papers with Massey transformed the study of the terrestrial ionosphere into a quantitative discipline of enquiry.