Thomas Young



Thomas Young (*June 14, 1773 – †May 10, 1829) was an English researcher, physician and polymath. He is sometimes considered to be "the last person to know everything": that is, he was familiar with virtually all the contemporary Western academic knowledge at that point in history. . Young also wrote about various subjects to contemporary editions of the Encyclopedia Britannica. His learning was so prodigious in scope and breadth that he was popularly known as "Phenomenon Young."

Biography
Young belonged to a Quaker family of Milverton, Somerset, where he was born in 1773, the youngest of ten children. At the age of fourteen Young had learned Greek, Latin, French, Italian, Hebrew, Chaldean, Syriac, Samaritan, Arabic, Persian, Turkish and Amharic. .

Young began to study medicine in London in 1792, moved to Edinburgh in 1794, and a year later went to Göttingen, where he obtained the degree of doctor of physics in 1796. In 1797 he entered Emmanuel College, Cambridge. In the same year he inherited the estate of his grand-uncle, Richard Brocklesby, which made him financially independent, and in 1799 he established himself as a physician at 48 Welbeck Street, London (now recorded with a blue plaque). Young published many of his first academic articles anonymously to protect his reputation as a physician.

In 1801 Young was appointed professor of "natural philosophy" (mainly physics) at the Royal Institution. In two years he delivered 91 lectures. In 1802, he was appointed foreign secretary of the Royal Society, of which he had been elected a fellow in 1794. He resigned his professorship in 1803, fearing that its duties would interfere with his medical practice. His lectures were published in 1807 in the Course of Lectures on Natural Philosophy and contain a number of anticipations of later theories.

In 1811 Young became physician to St. George's Hospital, and in 1814 he served on a committee appointed to consider the dangers involved by the general introduction of gas into London. In 1816 he was secretary of a commission charged with ascertaining the length of the second's pendulum, and in 1818 he became secretary to the Board of Longitude and superintendent of the HM Nautical Almanac Office.

A few years before his death he became interested in life assurance, and in 1827 he was chosen one of the eight foreign associates of the French Academy of Sciences.

Thomas Young died in London on May 10, 1829.

Later scholars and scientists have praised Young's work although they may know him only through achievements he made in their fields. His contemporary Sir John Herschel called him a "truly original genius". Albert Einstein praised him in 1931 foreword to an edition of Newton's Opticks. Other admirers include physicist Lord Rayleigh and Nobel laureate Philip Anderson.

Double-slit experiment
In physics, Young is perhaps best known for his work in physical optics, as the author of series of research which did much to establish the wave theory of light, and as the discoverer of the interference of light. In Young's double-slit experiment, c. 1801, he passed a beam of light through two parallel slits in an opaque screen, forming a pattern of alternating light and dark bands on a white surface beyond. This led Young to reason that light was composed of waves or so thought—see Everything's Relative and Other Fables from Science and Technology by Tony Rothman, for a different caveat. (See also Newton wave-particle duality)

Young's modulus
Young also devised Young's modulus, a measure of the stiffness of a material.

Vision and colour theory
Young has also been called the founder of physiological optics. In 1793 he explained the mode in which the eye accommodates itself to vision at different distances as depending on change of the curvature of the crystalline lens; in 1801 he was the first to describe astigmatism; and in his Lectures he presented the hypothesis, afterwards developed by Hermann von Helmholtz, that colour perception depends on the presence in the retina of three kinds of nerve fibres which respond respectively to red, green and violet light. This theory was experimentally proven in 1959.

See also Young-Helmholtz theory

Medicine
In physiology Young made an important contribution to haemodynamics in the Croonian lecture for 1808 on the "Functions of the Heart and Arteries," and his medical writings included An Introduction to Medical Literature, including a System of Practical Nosology (1813) and A Practical and Historical Treatise on Consumptive Diseases (1815).

Languages
Young compared grammar and vocabulary of 400 languages (citation needed). In 1813 he introduced the term Indo-European languages, 165 years after the Dutch linguist and scholar Marcus Zuerius van Boxhorn made such a proposal in 1647.

Egyptian hieroglyphs
Young was also one of the first who tried to decipher Egyptian hieroglyphs, with Silvestre de Sacy and Akerblad who built up a demotic alphabet of 29 letters which was largely used by Young. But Akerblad believed that demotic was entirely phonetic or alphabetic and was wrong. By 1814 he had completely translated the "enchorial" (demotic, in modern terms) text of the Rosetta Stone (he had a list with 86 demotic words), and then studied the hieroglyphic alphabet but failed to recognise that demotic and hieroglyphic texts were paraphrases and not simple translations. In 1823 he published an Account of the Recent Discoveries in Hieroglyphic Literature and Egyptian Antiquities. Some of Young's conclusions appeared in the famous article "Egypt" he wrote for the 1818 edition of the Encyclopædia Britannica.

When the French linguist Jean-François Champollion published his translation of the hieroglyphs, Young praised his work but also stated that Champollion had based his system on Young's articles and tried to have his part recognized. Champollion, however, was unwilling to share the credit. In the forthcoming schism, strongly motivated by the political tensions of that time, the British supported Young and the French Champollion. Champollion, whose complete understanding of the hieroglyphic grammar showed the mistakes made by Young, maintained that he had deciphered alone the hieroglyphs. However, after 1826, he did offer Young access to demotic manuscripts in the Louvre, when he was a curator there.

Selected writings of Thomas Young

 * A Course of Lectures on Natural Philosophy and the Mechanical Arts (1807, republished 2002 by Thoemmes Press).
 * Miscellaneous Works of the Late Thomas Young, M.D., F.R.S. (1855, 3 volumes, editor John Murray, republished 2003 by Thoemmes Press).

Books

 * Robinson, Andrew. The Last Man Who Knew Everything: Thomas Young, the Anonymous Polymath Who Proved Newton Wrong, Explained How We See, Cured the Sick and Deciphered the Rosetta Stone. New York: Pi Press, 2005 (hardcover, ISBN 0-13-134304-1); Oxford: Oneworld Publications, 2006 (hardcover, ISBN 1-85168-494-8).