A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece. In general usage today a "clock" refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one's person are often distinguished from clocks.

The clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day; the lunar month; and the year. Devices operating on several different physical processes have been used over the millennia, culminating in the clocks of today.

The study of timekeeping is known as horology.

Read more about Clock:  Sundials and Other Devices, Water Clocks, Early Mechanical Clocks, How Clocks Work, Types, Purposes, Seismology, Specific Types of Clocks

Other articles related to "clock, clocks":

Specific Types of Clocks
... By mechanism By function By style Astronomical clock Atomic clock Candle clock Congreve clock Digital clock Electric clock Flip clock Hourglass Incense clock Mechanical watch Oil-lamp clock ...
Floral Clock
... A floral clock or flower clock is a large decorative clock with the clock face formed by carpet bedding, usually found in a park or other public recreation area ... The first floral clock was invented by John McHattie of Edinburgh Parks and was first planted up in the spring of 1903 in West Princes Street Gardens ... In Edinburgh the clock mechanism is set inside the plinth of the statue to Allan Ramsay adjacent and lasted until 1936 ...
Christian Marclay - Selected Exhibitions
... The Clock - 14 September to 25 November 2012 - The Power Plant Gallery Toronto, Canada The Clock – March to June 2012 – Museum of Contemporary ...
Simon Willard Clocks - Legacy
... Nowadays, Simon Willard's clocks are recognized as American masterpieces ... In perfect condition, a Simon Willard's clock is usually sold from $50,000 up to $250,000 ... The Willard brothers revolutionized clock manufacturing by both division of labor and by using multiple previously molded parts ...
Modified Frequency Modulation - MMFM
... M²FM, or M2FM, is similar to MFM, but suppresses additional clock bits, producing a longer maximum run length (a (1,4) RLL code) ... In particular, a clock pulse is only inserted between a pair of adjacent 0 bits if the first bit of the pair did not have a clock pulse inserted before it ... In the example below, clock bits that would have been present in MFM are noted in bold Data 1 ... Clock 0. 0 ...

Famous quotes containing the word clock:

    The source of poetry that
    seeing the clock stopped, says,
    The clock has stopped

    that ticked yesterday so well?
    William Carlos Williams (1883–1963)

    What brought them there so far from their home,
    Cuchulain that fought night long with the foam,
    What says the Clock in the Great Clock Tower?
    Niamh that rode on it; lad and lass
    That sat so still and played at the chess?
    What but heroic wantonness?
    William Butler Yeats (1865–1939)