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  2. History of timekeeping devices - Wikipedia

    en.wikipedia.org/wiki/History_of_timekeeping_devices

    The idea of using atomic transitions to measure time was first suggested by the British scientist Lord Kelvin in 1879, [204] although it was only in the 1930s with the development of magnetic resonance that there was a practical method for measuring time in this way. [205] A prototype ammonia maser device was built in 1948 at NIST. Although ...

  3. Timeline of time measurement inventions - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_time...

    This timeline of time measurement inventions is a chronological list of particularly important or significant technological inventions relating to timekeeping devices and their inventors, where known. Note: Dates for inventions are often controversial. Sometimes inventions are invented by several inventors around the same time, or may be ...

  4. Hourglass - Wikipedia

    en.wikipedia.org/wiki/Hourglass

    Unlike most other methods of measuring time, the hourglass concretely represents the present as being between the past and the future, and this has made it an enduring symbol of time as a concept. The hourglass, sometimes with the addition of metaphorical wings, is often used as a symbol that human existence is fleeting, and that the " sands of ...

  5. Unit of time - Wikipedia

    en.wikipedia.org/wiki/Unit_of_time

    A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world , is the second , defined as about 9 billion oscillations of the caesium atom.

  6. Clock - Wikipedia

    en.wikipedia.org/wiki/Clock

    An analog pendulum clock made around 18th century. A clock or chronometer is a device that measures and displays time.The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, and the year.

  7. 50 Inventions From The Past That Were Amazingly Innovative - AOL

    www.aol.com/98-historical-inventions-were-ahead...

    When you think of a vending machine, things like snacks, sodas, or even pharmaceutical supplies may come to mind. But you might be surprised to know that the first ever vending machine actually ...

  8. Time clock - Wikipedia

    en.wikipedia.org/wiki/Time_clock

    Early time clock, made by National Time Recorder Co. Ltd. of Blackfriars, London at Wookey Hole Caves museum A Bundy clock used by Birmingham Corporation Transport. An early and influential time clock, sometimes described as the first, was invented on November 20, 1888, by Willard Le Grand Bundy, [4] a jeweler in Auburn, New York.

  9. John Harrison - Wikipedia

    en.wikipedia.org/wiki/John_Harrison

    John Harrison (3 April [O.S. 24 March] 1693 – 24 March 1776) was an English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of how to calculate longitude while at sea.