John Herschel
John Frederick William Herschel (March 7, 1792 – May 11, 1871) was an English mathematician and astronomer. He was the son of astronomer William Herschel.
John Herschel originated the use of the Julian day system in astronomy and made several important contributions to the improvement of photographic processes (Cyanotype). He coined the terms "photography", "negative", and "positive", and discovered sodium thiosulphite as a fixer of silver halides.
Herschel was born at Slough, Buckinghamshire, and studied at Eton College and St John's College, Cambridge. He graduated as senior wrangler in 1813. It was during his time as an undergraduate that he became friends with Charles Babbage and George Peacock. He took up astronomy in 1816, building a reflecting telescope with a mirror 18 inches in diameter and with a 20 foot focal length. Between 1821 and 1823 he re-examined, with James South, the double stars catalogued by his father. For this work he was presented in 1826 with the Royal Astronomical Society's gold medal; and with the Lalande Medal of the French Institute in 1825; while the Royal Society had in 1821 bestowed upon him the Copley Medal for his mathematical contributions to their Transactions. He was knighted in 1831.
In 1833 Herschel travelled to South Africa in order to catalogue the stars of the southern skies. Amongst his other observations during this time was that of the return of Comet Halley. He returned to England in 1838 and published Results of Astronomical Observations made at the Cape of Good Hope in 1847. In this publication he proposed the names still used today for the seven then-known satellites of Saturn: Mimas, Enceladus, Tethys, Dione, Rhea, Titan and Iapetus.[1] In the same year Herschel received his second Copley Medal from the Royal Society for this work.
Herschel's other works included Outlines of Astronomy (1849); General Catalogue of 10,300 Multiple and Double Stars, (published posthumously); Familiar Lectures on Scientific Subjects; and General Catalogue of Nebulae and Clusters. At his death he was given a national funeral and buried in Westminster Abbey.
In 1835, the New York Sun newspaper wrote a series of satiric articles that came to be known as the Great Moon Hoax, with statements falsely attributed to John Herschel about his supposed discoveries of animals living on the Moon, including batlike winged humanoids.
He had three sons: one of whom, Alexander Stewart Herschel, was also an astronomer. He also had nine daughters.