Christiaan Huygens (pronounced in English (IPA): [ˈhaɪg
ənz]; in Dutch: [ˈhœy γəns]) (April 14, 1629–July 8, 1695), was a Dutch mathematician and physicist;
born in The Hague as the son of Constantijn Huygens. He studied law at the University of Leiden and the College of Orange
in Breda before turning to science. Historians commonly associate Huygens with the scientific revolution.
Huygens generally receives minor credit for his role in the development
of modern calculus. He also achieved note for his arguments that light consisted of waves; see: wave-particle duality. In
1655, he discovered Saturn's moon Titan. He also examined Saturn's planetary rings, and in 1656 he discovered that those rings
consisted of rocks. In the same year he observed the Orion Nebula. Using his modern telescope he succeeded in subdividing
the nebula into different stars. (The brighter interior of the Orion Nebula bears the name of the Huygens Region in his honour.)
He also discovered several interstellar nebulae and some double stars.
After Blaise Pascal encouraged him to do so, Huygens wrote the first
book on probability theory, which he had published in 1657.
He also worked on the construction of accurate clocks, suitable for
naval navigation. In 1658 he published a book on this topic called Horologium. In fact his invention, the pendulum clock (patented
1656), was a breakthrough in timekeeping. Devices known as escapements regulate the rate of a watch or clock, and the anchor
escapement represented a major step in the development of accurate watches. Huygens observed that two pendulums mounted on
the same beam will come to swing in perfectly opposite directions, an observation he referred to as odd sympathy.
Huygens also developed a balance-spring clock more or less contemporaneously
with, though separately from, Robert Hooke, and controversy over whose invention was the earlier persisted for centuries.
In February 2006, a long-lost copy of Hooke's handwritten notes from several decades' Royal Society meetings was discovered
in a cupboard in Hampshire, and the balance-spring controversy appears by evidence contained in those notes to be settled
in favor of Hooke's claim.
The Royal Society elected Huygens a member in 1663. In the year 1666
Huygens moved to Paris where he held a chair at the French Royal Society. Using the Paris Observatory (completed in 1672)
he made further astronomical observations.
Huygens speculated in detail about life on other planets (although
we do not know to what extent ancient writers exercised such speculation, since most of their work has not survived). In his
book Cosmotheoros, further entitled The celestial worlds discover'd: or, conjectures concerning the inhabitants, plants and
productions of the worlds in the planets (see online edition) he imagined a universe brimming with life, much of it very similar
to life on 17th century Earth. The liberal climate in the Netherlands of that time not only allowed but encouraged such speculation.
In sharp contrast, philosopher Giordano Bruno, who also believed in many inhabited worlds, was burned at the stake by the
Italian authorities for his beliefs in 1600.
In 1675, Christian Huygens patented a pocket watch. He also invented
numerous other devices, including a 31 tone to the octave keyboard instrument which made use of his discovery of 31 equal
Huygens moved back to The Hague in 1681 after suffering serious illness
and died there 14 years later on July 8, 1695.