Young's interference experiment

In the second half of the 17th century two hypotheses for the nature of light were discussed. Robert Hooke, Christiaan Huygens advocated a wave theory, while Isaac Newton, who did many experimental investigations of light, developed his corpuscular theory of light according to which light is emitted from a luminous body in the form of tiny particles. By the end of the 18th century Newton's reputation as the preeminent physicist gave the emission theory a wide lead. Even the famous Leonhard Euler who supported the wave theory was unable to encourage its discussion. ==Young's work on wave theory==

While studying medicine at Göttingen in the 1790s, Young wrote a thesis on the human voice. To practice medicine in England Young was required to spend three years at an English university. Young presented the Royal Society Bakerian prize lecture in 1800, 1801, and 1803. The 1801 lecture, "On the Theory of Light and Colours" described various interference phenomena and was published in 1802.The first of Young's Bakerian lectures was published in the spring of 1802. Relation to the double-slit experiment In 1803, Young described an experiment with two slits. In modern times this experiment is considered an important classic proof of the wave theory of light. However it is not clear which experiments Young performed and which ones he described as thought experiments. He also mentions the possibility of passing light through two slits in his description of the experiment: Criticism In the years 1803–1804, a series of unsigned attacks on Young's theories appeared in the Edinburgh Review. The anonymous author (later revealed to be Henry Brougham, a founder of the Edinburgh Review) succeeded in undermining Young's credibility among the reading public sufficiently that a publisher who had committed to publishing Young's Royal Institution lectures backed out of the deal. This incident prompted Young to focus more on his medical practice and less on physics. ==Acceptance of the wave theory of light==

In 1817, the corpuscular theorists at the French Academy of Sciences which included Siméon Denis Poisson were so confident that they set the subject for the next year's prize as diffraction, being certain that a particle theorist would win it. Augustin-Jean Fresnel submitted a thesis based on wave theory and whose substance consisted of a synthesis of the Huygens' principle and Young's principle of interference. and observed the predicted spot. This convinced most scientists of the wave-nature of light. In the end, Fresnel won the competition. Arago later noted that the phenomenon (which is sometimes called the Arago spot) had already been observed by Joseph-Nicolas Delisle == See also ==