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":

Modified Frequency Modulation - MMFM
... 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 ... Encoded ...
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, Edinburgh ... 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 Art, Sydney, Australia The Clock – 10 ...
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 ...
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 ...

Famous quotes containing the word clock:

    The clock runs down
    timeless and still.
    The days and nights turn hours to years
    and water in a gutter marks the circle of another world
    hating, resentful, and afraid
    stagnant, and green, and full of slimy things.
    Margaret Abigail Walker (b. 1915)

    A junky runs on junk time. When his junk is cut off, the clock runs down and stops. All he can do is hang on and wait for non-junk time to start.
    William Burroughs (b. 1914)