Search results
Results From The WOW.Com Content Network
The categorisation of the past into discrete, quantified named blocks of time is called periodization. [1] This is a list of such named time periods as defined in various fields of study. These can be divided broadly into prehistorical periods and historical periods (when written records began to be kept).
Tertiary (/ ˈ t ɜːr. ʃ ə. r i, ˈ t ɜː r. ʃ i ˌ ɛr. i / TUR-shə-ree, TUR-shee-err-ee) [1] is an obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the extinction of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to the beginning of the Quaternary glaciation at ...
See history, history by period, and periodization for different organizations of historical events. For earlier time periods, see Timeline of the Big Bang, Geologic time scale, Timeline of evolution, and Logarithmic timeline
7 d: Historically sometimes also called "sennight". decaday 10 d (1 Dd) 10 days. A period of time analogous to the concept of "week", used by different societies around the world: the ancient Egyptian calendar, the ancient Chinese calendar, and also the French Republican calendar (in which it was called a décade). megasecond: 10 6 s: About 11. ...
His 100-year life (311.04 trillion years) is called a mahā-kalpa, which is followed by a mahā-pralaya (full dissolution) of equal length, where the bases of the universe, prakriti, is manifest at the start and unmanifest at the end of a maha-kalpa. His 100-year life is divided into two 50-year periods, each called a parārdha.
In geochronology, time is generally measured in mya (million years ago), each unit representing the period of approximately 1,000,000 years in the past. The history of Earth is divided into four great eons, starting 4,540 mya with the formation of the planet. Each eon saw the most significant changes in Earth's composition, climate and life.
This category's scope is limited to human-related history since the end of Earth's most recent glacial period ("the Ice Age") around 10,000 to 15,000 years ago. See also. List of time periods, which includes periods used in fields such as palaeogeography, palaeoecology, archaeology and cosmology.
Terrestrial Time (TT) is a modern astronomical time standard defined by the International Astronomical Union, primarily for time-measurements of astronomical observations made from the surface of Earth. [1] For example, the Astronomical Almanac uses TT for its tables of positions (ephemerides) of the Sun, Moon and planets as seen from Earth.