User:Toaster83/Thomas Young



Thomas Young (June 13, 1773 – May 10, 1829) was an English scientist and researcher. He is sometimes considered to be "the last person to know everything": that is, he was familiar with virtually all the Western academic knowledge at that point in history. Clearly this can never be verified, and other claimants to this title are Gottfried Leibniz, Leonardo da Vinci, and Francis Bacon, among others.

Biography
Young belonged to a Quaker family of Milverton, Somerset, where he was born in 1773, the eldest of ten children. His parents were Thomas and Sarah Young.

By 1787, when Young was fourteen years of age, he was already acquainted with Greek, Latin, French, Italian, Hebrew, Chaldean, Syriac, Samaritan, Arabic, Persian, Turkish and Amharic. During the same year, he began his education outside of Somerset with Hudson Guerney, who would become Young's lifelong friend. At fifteen, he fell ill with pulmonary tuberculosis, from which he fully recovered.

Beginning his study of medicine in London in 1792, he moved to Edinburgh in 1794 and then to Göttingen a year later. At Göttigen University he added German to his repetoire of languages. He obtained the degree of doctor of physics from there in 1796. In his dissertation, he formulated an alphabet to describe all the possible sounds that the human voice can create. In 1797 he entered Emmanuel College, Cambridge because recent changes in rules at the College of Physicians required him to study two years at the same university. In the same year the death of his grand-uncle, Richard Brocklesby, made him financially independent, and in 1799 he established himself as a physician in Welbeck Street, London. He received his M.D. in 1808, five years after earning his bachelor of medicine (M.B.). One year later, he became a Fellow of the Royal College of Physicians (F.R.C.P.).

Appointed in 1801 professor of physics at the Royal Institution, in two years he delivered 91 lectures. These lectures, printed in 1807 (Course of Lectures on Natural Philosophy), contain a remarkable number of anticipations of later theories. He resigned his professorship in 1803, fearing that its duties would interfere with his medical practice. Ultimately, his medical practice would never really take off, and he would rely on his breadth of knowledge in other fields to occupy his time.

In 1802, he was appointed foreign secretary of the Royal Society, of which he had been elected a fellow in 1794. In 1811 he became physician to St. George's Hospital, a position he would hold until his untimely death. 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 seconds 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 to be one of eight foreign associates of the French Academy of Sciences. He died a premature death in London on May 10, 1829. A post-mortem examination of Young's body revealed he died from "ossification of the aorta", known better today as atherosclerosis with calcification. How exactly he developed the condition remains unclear to this day.

Double-slit experiment
Young is perhaps best known for his work in physical optics, as the author of a remarkable series of researches 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. (See also Newton, Isaac, wave-particle duality)

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

Vision
He 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 described the defect known as astigmatism; and in his Lectures he put forward 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. In physiology he made an important contribution to haemadynamics 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).

Hieroglyphics
In another field of research, he was one of the first successful workers at the decipherment of Egyptian hieroglyphics; by 1814 he had completely translated the enchorial (demotic) text of the Rosetta Stone, and a few years later had made considerable progress towards an understanding of the hieroglyphic alphabet. In 1823 he published an Account of the Recent Discoveries in Hieroglyphic Literature and Egyptian Antiquities. Some of his conclusions appeared in the famous article "Egypt," which he wrote for the 1818 Encyclopædia Britannica.

Publications
list of his publications to be added here