When.com Web Search

  1. Ads

    related to: clock with exact seconds

Search results

  1. Results From The WOW.Com Content Network
  2. International Atomic Time - Wikipedia

    en.wikipedia.org/wiki/International_Atomic_Time

    International Atomic Time. International Atomic Time (abbreviated TAI, from its French name temps atomique international[1]) is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid. [2] TAI is a weighted average of the time kept by over 450 atomic clocks in over 80 national laboratories ...

  3. Atomic clock - Wikipedia

    en.wikipedia.org/wiki/Atomic_clock

    The SI second is defined as a certain number of unperturbed ground-state hyperfine transitions of the caesium-133 atom. Caesium standards are therefore regarded as primary time and frequency standards. Caesium clocks include the NIST-F1 clock, developed in 1999, and the NIST-F2 clock, developed in 2013. [42] [43]

  4. 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. The exact modern SI definition is " [The second] is ...

  5. Second - Wikipedia

    en.wikipedia.org/wiki/Second

    The earliest clocks to display seconds appeared during the last half of the 16th century. The second became accurately measurable with the development of mechanical clocks. The earliest spring-driven timepiece with a second hand that marked seconds is an unsigned clock depicting Orpheus in the Fremersdorf collection, dated between 1560 and 1570.

  6. Doomsday Clock - Wikipedia

    en.wikipedia.org/wiki/Doomsday_Clock

    The Doomsday Clock is a symbol that represents the likelihood of a human-made global catastrophe, in the opinion of the members of the Bulletin of the Atomic Scientists. [1] Maintained since 1947, the Clock is a metaphor, not a prediction, for threats to humanity from unchecked scientific and technological advances.

  7. Unix time - Wikipedia

    en.wikipedia.org/wiki/Unix_time

    Unix time[a] is a date and time representation widely used in computing. It measures time by the number of non- leap seconds that have elapsed since 00:00:00 UTC on 1 January 1970, the Unix epoch. In modern computing, values are sometimes stored with higher granularity, such as microseconds or nanoseconds.