“Young was a true polymath, with interests ranging from physics to Egyptology. He was born in 1773 in Milverton, in southwest England, into a large Quaker family. He was a prodigy as a child, learning to read by age two, and teaching himself Latin at age six.”
“His major contribution to the field of light is the double-slit experiment (1801), which has been considered not only «one of the most beautiful experiments in physics», but also «the favourite experiment with light.» With this experiment Young challenged the theories of Isaac Newton and proved that light is a wave, because light suffers the phenomenon of interference that is typical of the waves. Between 1801 and 1803, Young delivered a series of lectures to the Royal Society underlining the wave theory of light and adding to it a new fundamental concept, the so-called principle of interference. The double-slit experiment is a wonderfully simple experiment, which allowed Thomas Young to demonstrate convincingly the wave nature of light for the first time. When the waves emerging from two narrow slits are superimposed on a screen placed at some distance parallel to the line connecting these slits, a pattern of bright and dark fringes regularly spaced appears on the screen (interference pattern). This is the first clear proof that light added to light can produce darkness. Interference is accompanied by a spatial redistribution of the optical intensity without violation of power conservation. This phenomenon is known as interference and thanks to this experiment t’he intuitive ideas of Huygens regarding the wave nature of light were confirmed. “
https://www.aps.org/publications/apsnews/200805/physicshistory.cfm