Thomas Young

By Skim944

Born June 13, 1773 in the town of Milverton, Somerset, England, Thomas Young was an English physician who made large contributions to the studies of light, vision, energy, language, and Egyptology, among many others. Although his name does not hold the status of Einstein’s or Newton’s, his work in developing Young’s Modulus, deciphering the Rosetta Stone, discovery of light’s wave nature, and coining the scientific definition of the word energy have spurred scientific understanding in key areas that still impact life today.

Personal Life

Early Life

Born as the eldest of 10 children to a Quaker family in 1773, Thomas Young demonstrated his profound intelligence early on; he began to read at the age of two, and by six, he had read the Bible twice and started his study of Latin. After attending boarding school form 1780 to 1786, Young initiated independent study of 8 other languages to add to his fluency in Latin, Greek, French, and Italian. He then went on to study medicine at London, Edinburgh, and Göttingen as well as Emmanuel College, Cambridge, earning two doctorate degrees in 1796 and in 1808.

Adulthood

In 1800, Young moved to London to begin his medical practice, which was not very successful. A year later, he became the professor of natural philosophy at the Royal Institution, where he lectured about mechanical arts as well as natural philosophy for the members of the Institution. His intelligence became his undoing here, as his lectures were too technical and detailed for his general audience, so he resigned and resumed his medical practice in London. On June 4, 1804, he married Eliza Maxwell, a member of the Scottish aristocracy. Throughout the rest of his lifetime, Thomas Young held many other positions, including: physician at St. George’s Hospital (January 1811), inspector of calculations and physician of the Palladium Insurance Company (March 1824), anonymous author of numerous articles, foreign secretary of the Royal Society, secretary of the Royal Commission on Weights and Measurements, and Superintendent of the Nautical Almanac, among many others. He maintained a high social status due to his marriage and had a large sum of money with which to continue his scholarly pursuits, allowing him to make numerous discoveries that advanced the fields of light and energy.

Death

On May 10, 1829, Thomas Young died in London and was buried at St. Giles Church in Kent, England. Many later scientists have praised him and his work, including Sir John Herschel and Albert Einstein.

Scientific Work

Wave Theory of Light

Thomas Young received much criticism for proposing his theory that light propagates through mediums in the form of waves because the scientific community clung to the century-old Newtonian belief that light is comprised of particles. He discovered this wave nature of light through a simple experiment, where he allowed light to pass through two small holes onto a screen. The light formed bands of light and darkness, demonstrating the idea of wave interference. In the bands of light, the crests and troughs of the two sources of light waves aligned and reflected off the screen. However, in the bands of darkness, the crests of one source of light lined up with the troughs of another, resulting in interference. The waves essentially “cancel” each other out, causing the bands of darkness. Newton proposed that there are seven basic colors of light; with his wave theory, Young calculated the relative wavelengths of all seven colors as they appeared on thin films, like soap bubbles. In 1817, Young proposed that when light propagates through a medium, it travels at right angles to its direction of travel as opposed to in the same direction, explaining the concept of polarization.

Young’s Modulus

Young proposed that the elasticity of matter can be described as a ratio between the stress on a body to the strain (the change in length compared to the total length of the body). Previously, engineers were required to use Hooke’s Law and physical experiments for any new component, as different combinations of materials and geometry affect the constant k, and thus the predicted load that the component is able to bear. However, Young’s Modulus only depends on the type of the material, making the shape of that material irrelevant in calculating the load-bearing capacity of the material, revolutionizing engineering methods as a whole.

Young-Helmholtz Trichromatic Theory and Vision

Previously, scientists theorized that the human eye contained an individual receptor for every individual color that passes through the lens. However, Young along with Hermann von Helmholtz introduced the idea that the eye only requires three separate nerve endings, one each sensitive to red, blue, and green, to interpret color. Modern understanding of the anatomy of the eye has proved their theory correct; the eye contains three color receptors that combine information to form human interpretation of the entire visible color spectrum. Young also discovered that the eye accommodates itself to different stimuli by changing the shape and size of the lens, which led him to be the first to describe astigmatism.

Rosetta Stone

Along with his other scientific pursuits, Young was an avid linguist specifically interested in Egyptian culture. He began his work in deciphering ancient Egyptian hieroglyphics in 1813, when work was already in progress. By 1814, he had completely translated the demotic Egyptian script (the written language of scripts that didn’t require the ideographs of hieroglyphics) from the ancient Greek written on the tablet, greatly contributing to the decipherment of the Ancient Egyptian language.

Awards

Thomas Young himself did not receive any awards, but instead has an award named after him. The Young Medal and Prize is awarded for research done in the field of optics, and the prize money is 1000 pounds.