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  2. List of time periods - Wikipedia

    en.wikipedia.org/wiki/List_of_time_periods

    Early modern period – The chronological limits of this period are open to debate. It emerges from the Late Middle Ages (c. 1500), demarcated by historians as beginning with the fall of Constantinople in 1453, in forms such as the Italian Renaissance in the West, the Ming dynasty in the East, and the rise of the Aztecs in the New World.

  3. Unit of time - Wikipedia

    en.wikipedia.org/wiki/Unit_of_time

    1.44 minutes, or 86.4 seconds. Also marketed as a ".beat" by the Swatch corporation. moment: 1/40 solar hour (90 s on average) Medieval unit of time used by astronomers to compute astronomical movements, length varies with the season. [4] Also colloquially refers to a brief period of time. centiday 0.01 d (1 % of a day) 14.4 minutes, or 864 ...

  4. Orders of magnitude (time) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(time)

    1 fs: The cycle time for ultraviolet light with a wavelength of 300 nanometres; The time it takes light to travel a distance of 0.3 micrometres (μm). 7.58fs: The period of vibration of a hydrogen molecule. 140 fs: The time needed for electrons to have localized onto individual bromine atoms 6 Ångstrom apart after laser dissociation of Br 2. [11]

  5. List of the most distant astronomical objects - Wikipedia

    en.wikipedia.org/wiki/List_of_the_most_distant...

    This article documents the most distant astronomical objects discovered and verified so far, and the time periods in which they were so classified. For comparisons with the light travel distance of the astronomical objects listed below, the age of the universe since the Big Bang is currently estimated as 13.787±0.020 Gyr.

  6. Chronology of the universe - Wikipedia

    en.wikipedia.org/wiki/Chronology_of_the_universe

    The earliest "modern" Population I stars are formed in this period. Present time: 13.8 Ga 0 2.7 K Farthest observable photons at this moment are CMB photons. They arrive from a sphere with a radius of 46 billion light-years. The spherical volume inside it is commonly referred to as the observable universe.

  7. Doomsday Clock - Wikipedia

    en.wikipedia.org/wiki/Doomsday_Clock

    The farthest time from midnight was 17 minutes in 1991, and the nearest is 89 seconds, set in January 2025. [ 5 ] The Clock was moved to 150 seconds (2 minutes, 30 seconds) in 2017, then forward to 2 minutes to midnight in 2018, and left unchanged in 2019. [ 6 ]

  8. List of decades, centuries, and millennia - Wikipedia

    en.wikipedia.org/wiki/List_of_decades,_centuries...

    List of years; Timelines of world history; List of timelines; Chronology; See calendar and list of calendars for other groupings of years.; See history, history by period, and periodization for different organizations of historical events.

  9. Rotation period (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Rotation_period_(astronomy)

    In astronomy, the rotation period or spin period [1] of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the sidereal rotation period (or sidereal day ), i.e., the time that the object takes to complete a full rotation around its axis relative to the background stars ( inertial space ).