James Clerk Maxwell

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James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish theoretical physicist and mathematician. His most important achievement was classical electromagnetic theory, synthesizing all previously unrelated observations, experiments and equations of electricity, magnetism and even optics into a consistent theory. His set of equations—Maxwell's equations—demonstrated that electricity, magnetism and even light are all manifestations of the same phenomenon: the electromagnetic field. From that moment on, all other classic laws or equations of these disciplines became simplified cases of Maxwell's equations. Maxwell's work in electromagnetism has been called the "second great unification in physics", after the first one carried out by Isaac Newton.

Colour analysis

File:Tartan Ribbon.jpg

The first permanent colour photograph, taken by James Clerk Maxwell in 1861.

Amongst his many accomplishments Maxwell contributed to the area of optics and colour vision, and is credited with the discovery that colour photographs could be formed using red, green, and blue filters. In 1861 he presented the world's first colour photograph during a Royal Institution lecture. He had Thomas Sutton, inventor of the single-lens reflex camera, photograph a tartan ribbon three times, each time with a different colour filter over the lens. The three images were reversal developed to form three colour separation transparencies, and then projected onto a screen with three different projectors, each equipped with the same colour filter used to take its image. When brought into focus, the three images formed a full colour image. The three photographic plates now reside in a small museum at 14 India Street, Edinburgh, the house where Maxwell was born.

However, in the strictest sense, this demonstration did not produce a tangible photograph, but a photographic image produced by three carefully aligned projectors. It served as a "proof of concept" of the possibility of colour photography, using the additive principle, where white is produced by the presence of all three additive primaries (red, green and blue).

From 1855 to 1872, he published at intervals a series of valuable investigations connected with the "Perception of colour" and "Colour-blindness", for the earlier of which the Royal Society awarded him the Rumford Medal. The instruments which he devised for these investigations were simple and convenient in use. For example, Maxwell's discs were used to compare a variable mixture of three primary colours with a sample colour by observing the spinning "colour top."