Huygens, Christiaan (krĭs`tyän hoi`gəns), 1629–95, Dutch mathematician and physicist; son of Constantijn Huygens. He improved telescopic lenses and discovered (1655) a satellite of Saturn and studied the rings of Saturn. His findings were described in his Systema Saturnium (1659). He was the first to use the pendulum in clocks. He developed a wave theory of light opposed to the corpuscular theory of Newton and formulated Huygens's principle, which holds that, concerning light waves, every point on a wave front is itself a source of new waves. In 1678 he discovered the polarization of light by double refraction in calcite. His chief work is Horologium oscillatorium (1673).

Bibliography

See his Oeuvres complètes (22 vol. in 23, 1888–1950); study by A. E. Bell (1947); A. Elzinga, On a Research Program in Early Modern Physics (1972).

Huygens, Christiaan

or Christian Huyghens

Christiaan Huygens, portrait by C. Netscher, 1671; in the Collection Haags Gemeentemuseum, The Hague

(credit: Courtesy of the Collection Haags Gemeentemuseum, The Hague)

(born April 14, 1629, The Hague—died July 8, 1695, The Hague) Dutch mathematician, astronomer, and physicist. He was the first to use a pendulum to regulate a clock (1656). He invented a method of grinding and polishing telescope lenses, and he used his telescopes to discover the true shape of Saturn's rings (1659). He developed explanations of reflection and refraction based on the principle of secondary wave fronts, now called Huygens' principle. He developed the wave theory of light (1678) and also contributed to the science of dynamics. His work on rotating bodies led to solutions of problems involving oscillation of a pendulum and uniform circular motion. He was also the first to determine acceleration due to gravity.