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  2. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    [2] [3] Estimates on the number of Earth's current species range from 10 million to 14 million, [4] with about 1.2 million or 14% documented, the rest not yet described. [5] However, a 2016 report estimates an additional 1 trillion microbial species, with only 0.001% described.

  3. List of radioactive nuclides by half-life - Wikipedia

    en.wikipedia.org/wiki/List_of_radioactive...

    This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.

  4. Orders of magnitude (time) - Wikipedia

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

    6 × 10 43 Qs (2 × 10 66 years): The approximate lifespan of a black hole with the mass of the Sun [21] 4 × 10 63 Qs (1.3 × 10 86 years): The approximate lifespan of Sagittarius A*, if uncharged and non-rotating [21] 5.4 × 10 83 Qs (1.7 × 10 106 years): The approximate lifespan of a supermassive black hole with a mass of 20 trillion solar ...

  5. Timeline of human evolution - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_human_evolution

    Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago [32] during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago [33] (late Miocene). A. ramidus had a small brain, measuring between 300 and 350 cm 3.

  6. Pleistocene - Wikipedia

    en.wikipedia.org/wiki/Pleistocene

    The Pleistocene has been dated from 2.580 million (±0.005) to 11,700 years BP [10] with the end date expressed in radiocarbon years as 10,000 carbon-14 years BP. [11] It covers most of the latest period of repeated glaciation , up to and including the Younger Dryas cold spell.

  7. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    The numeric values on the International Chronostratigrahpic Chart are represented by the unit Ma (megaannum, for 'million years'). For example, 201.4 ± 0.2 Ma, the lower boundary of the Jurassic Period, is defined as 201,400,000 years old with an uncertainty of 200,000 years.

  8. Reuters 3 hours ago ... If you’d invested $1,000 in Bitcoin 10 years ago, here’s how much you’d have now. ... Benzinga 14 minutes ago

  9. Timeline of glaciation - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_glaciation

    The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago. Within ice ages, there exist periods of more severe glacial conditions and more temperate conditions, referred to as glacial periods and interglacial periods , respectively.