John Carroll (astronomer)

British astronomer and physicist

Sir John Anthony Carroll (8 January 1899 – 2 May 1974) was a British astronomer and physicist. In the 1920s he worked at the Solar Physics Observatory, Cambridge, UK with F. J. M. Stratton and Richard van der Riet Woolley. He made major technological advances, inventing a high resolution spectrometer, and (with C G Fraser) a coronal camera.

He was born near Manchester and educated at King's School in Chester, before winning a scholarship to study at Sidney Sussex College, Cambridge, in 1916. However, he decided to postpone Cambridge, and instead enlisted for service in the First World War, finding an interesting role in the Royal Aircraft Establishment in Farnborough, to serve doing applied aeronautical science alongside George Paget Thomson. He suffered a heart attack in 1972 and spent the final two years of his life in ill health. He died on 2 May 1974.

He married twice, firstly in 1930 and secondly in 1951, the latter being to Jean Leslie Pole. He had one child by his first wife and two by the second.

Whilst Professor of Natural Philosophy at Aberdeen University, Carroll had been interested in acquiring desk computing machines for his students. These greatly reduced the labour in producing the mathematical tables needed in astronomy and other fields, including gunnery. In 1942 he became assistant director of research at the Scientific Research and Experiment Department, an Admiralty body which coordinated naval research departments. With Donald Sadler and John Todd, he formed the Admiralty Computing Service in 1943, which itself formed the basis for the NPL Mathematics Division when the Second World War ended in 1945. The NPL Maths Division offered a practical computing service and was also a centre of research into electronic computing and numerical analysis.