John Frederick William Herschel

Sir John Herschel, 1st Bt KH FRS
1867 photograph by Julia Margaret Cameron
Born	(1792-03-07)7 March 1792 Slough, Buckinghamshire, England
Died	11 May 1871(1871-05-11) (aged 79) Collingwood, near Hawkhurst, Kent, England
Resting place	Westminster Abbey
Residence	Slough Cape Town
Nationality	British
Education	Eton College
Alma mater	St John's College, Cambridge
Known for	The invention of photography
Influences	William Herschel (father)
Notable awards	Smith's Prize (1813) Copley Medal (1821) Lalande Medal (1825) Gold Medal of the Royal Astronomical Society (1826), (1836) Royal Medal (1836, 1840) Knight of the Royal Guelphic Order
Spouse	Margaret Brodie Stewart

Sir John Frederick William Herschel, 1st Baronet KH FRS (7 March 1792 – 11 May 1871) was an English polymath, mathematician, astronomer, chemist, inventor, and experimental photographer, who also did valuable botanical work. He was the son of Mary Baldwin and astronomer William Herschel, nephew of astronomer Caroline Herschel and the father of twelve children.

Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays; his Preliminary Discourse (1831), which advocated an inductive approach to scientific experiment and theory building, was an important contribution to the philosophy of science.

Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and William Herschel. He studied shortly at Eton College and St John's College, Cambridge, graduating as Senior Wrangler in 1813. It was during his time as an undergraduate that he became friends with Charles Babbage and George Peacock. He left Cambridge in 1816 and started working with his father. He took up astronomy in 1816, building a reflecting telescope with a mirror 18 inches (460 mm) in diameter and with a 20-foot (6.1 m) focal length. Between 1821 and 1823 he re-examined, with James South, the double stars catalogued by his father. He was one of the founders of the Royal Astronomical Society in 1820. For his work with his father, he was presented with the Gold Medal of the Royal Astronomical Society in 1826 (which he won again in 1836), and with the Lalande Medal of the French Academy of Sciences in 1825, while in 1821 the Royal Society bestowed upon him the Copley Medal for his mathematical contributions to their Transactions. Herschel was made a Knight of the Royal Guelphic Order in 1831.