1773-1829

English physician and physicist who established the wave theory of light with his experiments on interference patterns. Young's interest in sense perception led to the discovery of the cause of astigmatism. He explained the colors of thin films and the phenomenon of polarization, calculated the approximate wavelengths of different colors, investigated color perception, and developed methods for measuring surface tension and the size of molecules. His ideas about color perception are acknowledged in the Young-Helmholtz three-color theory. "Young's modulus," a constant in the mathematical equation describing elasticity, was named for him. Young was also a distinguished Egyptologist and helped decipher the Rosetta Stone.