Newton, (Sir) Isaac
1642/1643–1726/1727 (The difference is due to the use and report of the date in two calendars: Julian and Gregorian. According to the Gregorian calendar, the date of Newton’s birth was 4 Jan, 1643 and that of his death 31 March 1727) (Portrait of Isaac Newton in 1689 (age 46) by Godfrey Kneller, Wikimedia)
Isaac Newton was an English physicist and mathematician, who made seminal contributions to several domains of science, and was considered a leading scientist of his era and one of the most influential scientists of all time. He was born prematurely on 25 December 1642 in Lincolnshire, England, of Hannah Ayscough and Isaac Newton (father) . His father passed away before he was born. His mother remarried when he was 3 years old and he was left in the care of his grandmother, a situation he resented.
He attended the King’s School in Grantham where he learned Latin among other things until the age of 17. In 1661, he was admitted to Trinity College, Cambridge, and was educated in Aristotelian philosophy. However, Newton also read the works of Descartes, Galileo, and Kepler. In 1665/1666 he spent most of the time at his ancestral place in Lincolnshire because of the dangerous spread of plague in Cambridge. During that time he did most of his experimental work with glass prisms and much of his mental work that resulted in the publication of Principia in 1687.
In 1667 he returned to Cambridge and became a fellow of the College of the Holy and Undivided Trinity [2, 3]. In 1669, and at the age of 26, Newton became the Lucasian professor of mathematics. According to his secretary Humphrey Newton (no relation), his lectures were often poorly attended and few understood him and that sometimes he read to the walls . Newton occasionally traveled to London to attend the Royal Society lectures and was named a fellow in 1672. He became its president from 1703 to 1727. Newton was given various levels of support by the Royal Society. His interpretation of the optical experiments was strongly disputed by Robert Hooke, an employee of the society since 1664, as a result of which he published his book Opticks only in 1704, after Hooke’s death. He was supported by the society in his bitter and controversial dispute with the German polymath and philosopher Gottfried Wilhelm Leibniz over who had developed calculus first [Leibniz’s notations are used today].
Newton also dwelt in politics and was a member of the House of Commons between 1689 and 1690 and then again from 1701 to 1702. In 1705 he was knighted by Queen Anne during her visit to Trinity College. He held two government offices: first he was the Warden of the Mint from 1696 to 1700 and then Master of the Mint from 1700 until his death in 1727. At the time of Newton’s funeral, the French philosopher Voltaire who was in England compared Newton to Descartes and said of Newton that “he was never sensible to any passion, [and] was not subject to the common frailties of mankind, nor had any commerce with women” . Newton had strong opinions on religion and wrote a number of works, not published during his lifetime, that would have then been considered heretic in that period. Newton never married and died intestate in Kensington, London, when his relatives quarreled over the division of his considerable estate. He is buried in Westminster Abbey in London, England.
Newton’s Theory of Color
Arguably our modern understanding of light and color begins with Newton’s discovery of light dispersion which he published in 1672. In the late 1660s, Newton started experimenting with the phenomenon of colors and lectured on optics . At the time, it was generally thought that colors were mixtures of light and darkness. It was also believed that prisms imparted colors to light. Through observation of light refraction, Newton realized that this theory was incorrect. He demonstrated that a prism decomposes “white” light into a spectrum of colors. Newton obtained a triangular prism and began “to try therewith the celebrated Phaenomena of Colours.” In his notes he states, “having darkened my chamber, and made a small hole in my window-shuts, to let in a convenient quantity of the Sun's light, I placed my Prisme at this entrance, that it might be thereby refracted to the opposite wall. It was at first a very pleasing divertisement, to view the vivid and intense colours produced thereby; but after a while applying myself to consider them more circumspectly, I became surprised to see them in an oblong form, which, according to the received laws of Refraction, I expected should have been circular” . The original sketch demonstrates the dark room environment where this experiment was conducted (Fig. 1). He was the first to use the word spectrum (Latin for “appearance” or “apparition”) in this sense. He also used additional prisms to recombine the split components and showed that a spectral colored light does not change its properties by separating out a colored beam and shining it on various objects regardless of whether it was reflected or scattered or transmitted. With respect to colors Newton said “For the rays, to speak properly, are not coloured. In them there is nothing else than a certain power and disposition to stir up a sensation of this or that Colour” . During this period he also investigated the refraction of light and demonstrated that a multicolored spectrum produced by a prism could be recomposed into “white” light by a lens and a second prism . In the same period Newton observed that the angle of refraction of different colors by a prism is different . He noted that even when light rays in the form of a circular beam enter a prism, the spectrum of colors that exit in the position of minimum deviation is oblong. The length of the colored spectrum was in fact about five times as great as its breadth. He stated that it is the interaction of the object with light that creates the color of the object and not the object itself. This is known as Newton’s theory of color.
In 1704, Newton also discussed the corpuscular theory of light whereby light is considered to be made up of extremely small particles (which we now call photons). Newton argued that light is composed of particles or corpuscles, which were refracted by accelerating into a denser medium. To transmit forces between particles, Newton posited the existence of the ether. However, he replaced ether with occult forces based on Hermetic ideas of attraction and repulsion between particles and Newton’s considerable writings on alchemy. It has been said that “Newton was not the first of the age of reason: He was the last of the magicians.” Indeed, Newton’s interest in alchemy cannot be isolated from his contributions to science  since during his time there was no clear distinction between alchemy and science.
Later physicists favored a purely wavelike explanation of light to account for the interference patterns and the general phenomenon of diffraction. Later on, Young and Fresnel combined Newton’s particle theory with the wave theory and indicated that color is the visible manifestation of light’s wavelength.
The Color Circle
Newton proposed a method to determine the “fullness or intenseness” of combined colors on the circle based on the distance of the center of the combined gravity of the circles for each of the rays of light from whiteness (the distance from O to Z in the figure shown for Color Y, which arises from the composition of all the colors in the given mixture). The color circle was, if lacking the nonspectral colors, an early representation of what became centuries later, in a modified form, the chromaticity diagram. In his system, Newton had connected violet to red in the circle, and thus, a large gamut of purples was not shown. Newton described the complementary colors and their mixture and stated “If only two of the primary colours which in the circle are opposite to one another be mixed in an equal proportion,…, the colour compounded of these two shall not be perfectly white, but some faint anonymous colour.” . Newton’s concept of complementary colors was demonstrated more thoroughly in the nineteenth century by color theorists. Helmholtz established the complementary stimulus pairs, and Ogden Rood (1831–1902) emphasized that to reveal applied colors in their natural brilliance, a knowledge of the complementary hues was required .
A version of Newton’s color circle without the indigo blue was adopted by painters to describe complementary colors. Nonetheless, this circular diagram became the model for many color systems of the eighteenth and nineteenth centuries. The conceptual arrangement of colors in this form also allowed the painters’ primaries (red, yellow, blue) to be arranged opposite their complementary colors (e.g., red opposite green), as a way of denoting that each complementary color would enhance the other’s effect through optical contrast.
- 2.Westfall, R.S.: Never at Rest. Cambridge University Press (1980, 1998). ISBN 0-521-27435-4Google Scholar
- 3.Westfall, R.S.: Isaac Newton. Cambridge University Press (2007). ISBN 978-0-19-921355-9Google Scholar
- 4.More, L.T.: Isaac Newton A Biography 1642-1727. pp. 246, 381, and 389. Scribners, New York (1934)Google Scholar
- 5.Voltaire, F.M.A: Cassell & Co. In: Price, D., (ed.) Letters on England. p. 100. (1894). Also available in pdf form http://livros.universia.com.br/?dl_name=Letters-on-England-de-Voltaire.pdf
- 6.Newton, I.: Hydrostatics, Optics, Sound and Heat. Cambridge University Digital Library (c. 1670–c. 1710)Google Scholar
- 8.Newton, I.: Opticks, or A Treatise of the Reflections, Refractions, Inflections & Colours of Light. Dover Publications, New York (1952). Online version available on https://archive.org/details/opticksoratreat00newtgoog
- 9.Ball, W.W.R.: A Short Account of the History of Mathematics. Dover, New York (1908). ISBN 0-486-20630-0Google Scholar
- 10.Darrigol, O.: A History of Optics from Greek Antiquity to the Nineteenth Century (2012). ISBN-13: 978-0199644377Google Scholar
- 11.White, M.: Isaac Newton: The Last Sorcerer. Fourth Estate Limited (1997). ISBN 1-85702-416-8Google Scholar
- 12.Newton, I.: Of Colours. The Newton Project. http://www.newtonproject.sussex.ac.uk/view/texts/normalized/NATP00004. Retrieved 4 Apr 2015
- 13.Rood, O.N.: Modern Chromatics, with Application to Art and Industry. New York (1879). Also available on line: http://lcweb2.loc.gov/service/gdc/scd0001/2010/20100701001mo//20100701001mo.pdf
- 16.http://th.physik.uni-frankfurt.de/~jr/gif/stamps/stamp_newton.jpg. Visited 9 Apr 2015