Young, Thomas (1773–1829)
From 1800 to 1809 Young revived the wave theory of light, which opposed Newton's particle theory. In the 17th century the Dutch physicist Huygens suggested light was due to waves pushing outwards (longitudinal waves) from a source; Young however used up-and-down (transverse) waves (A), illustrated in his Course of Lectures on Natural Philosophy and Mechanical Arts (1807). Interference patterns (B) were explained by wave theory of light.
Thomas Young was a British linguist, physician, and physicist. His most significant achievement was in demonstrating optical interference, to resurrect the wave theory of light, which was occulted by Newton's particle theory. He also suggested that the eye responded to mixtures of three primary colors, and proposed the modulus of elasticity known as Young's modulus.