enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Doomsday Clock - Wikipedia

    en.wikipedia.org/wiki/Doomsday_Clock

    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.

  3. 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 ...

  4. Coordinated Universal Time - Wikipedia

    en.wikipedia.org/wiki/Coordinated_Universal_Time

    Coordinated Universal Time ( UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communication, navigation, scientific research, and commerce. UTC has been widely embraced by most countries and ...

  5. Atomic clock - Wikipedia

    en.wikipedia.org/wiki/Atomic_clock

    Coordinated Universal Time (UTC) is the result of comparing clocks in national laboratories around the world to International Atomic Time (TAI), then adding leap seconds as necessary. TAI is a weighted average of around 450 clocks in some 80 time institutions. [40]

  6. Second - Wikipedia

    en.wikipedia.org/wiki/Second

    Second. The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as 86400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400).

  7. Universal Time - Wikipedia

    en.wikipedia.org/wiki/Universal_Time

    Universal Time ( UT or UT1) is a time standard based on Earth's rotation. [1] While originally it was mean solar time at 0° longitude, precise measurements of the Sun are difficult. Therefore, UT1 is computed from a measure of the Earth's angle with respect to the International Celestial Reference Frame (ICRF), called the Earth Rotation Angle ...

  8. History of timekeeping devices - Wikipedia

    en.wikipedia.org/wiki/History_of_timekeeping_devices

    The time was determined by observing particular stars as they crossed the meridian. [24] The Jantar Mantar in Jaipur built in 1727 by Jai Singh II includes the Vrihat Samrat Yantra, 88 feet (27 m) tall sundial. [25] It can tell local time to an accuracy of about two seconds. [26]

  9. Unix time - Wikipedia

    en.wikipedia.org/wiki/Unix_time

    Definition. Unix time is currently defined as the number of non-leap seconds which have passed since 00:00:00 UTC on Thursday, 1 January 1970, which is referred to as the Unix epoch. [ 3] Unix time is typically encoded as a signed integer . The Unix time 0 is exactly midnight UTC on 1 January 1970, with Unix time incrementing by 1 for every non ...