and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference...

In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the...

the temperature of the universe was still too high to allow quarks to bind together to form hadrons. The quark epoch began approximately 10−12 seconds after...

to as Epoch time. This can be misleading since Unix time is not the only time system based on an epoch and the Unix epoch is not the only epoch used by...

The first picosecond (10−12 seconds) of cosmic time includes the Planck epoch, during which currently established laws of physics may not have applied;...

annihilated each other at the end of the hadron epoch. During the lepton epoch, the temperature of the Universe was still high enough to create neutrino and electron-positron...

theosophist authors, have called the time periods associated with these races Epochs (Steiner felt that the term "race" was not adequate anymore for modern humanity)...

-⁠stoh-; often referred to colloquially as the Ice Age) is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's...

or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern...

Holocene (/ˈhɒl.əsiːn, -oʊ-, ˈhoʊ.lə-, -loʊ-/) is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period...