[PAR] [TLE] Big Bang [SEP] The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution.  The model describes how the universe expanded from a very high density and high temperature state, and offers a comprehensive explanation for a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB), large scale structure and Hubble's law.  If the known laws of physics are extrapolated to the highest density regime, the result is a singularity which is typically associated with the Big Bang.  Physicists are undecided whether this means the universe began from a singularity, or that current knowledge is insufficient to describe the universe at that time.  Detailed measurements of the expansion rate of the universe place the Big Bang at around 13.8 billion years ago, which is thus considered the age of the universe.  After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later simple atoms. Giant clouds of these primordial elements later coalesced through gravity in halos of dark matter, eventually forming the stars and galaxies visible today. [PAR] [TLE] Primordial nuclide [SEP] In geochemistry, geophysics and geonuclear physics, primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed.  Primordial nuclides were present in the interstellar medium from which the solar system was formed, and were formed in the Big Bang, by nucleosynthesis in stars and supernovae followed by mass ejection, by cosmic ray spallation, and potentially from other processes.  They are the stable nuclides plus the long-lived fraction of radionuclides surviving in the primordial solar nebula through planet accretion until the present.  Only 286 such nuclides are known.
[PAR] [TLE] Big Bang [ SEP ] The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large - scale evolution . The model describes how the universe expanded from a very high density and high temperature state , and offers a comprehensive explanation for a broad range of phenomena , including the abundance of light elements , the cosmic microwave background ( CMB ) , large scale structure and Hubble 's law . If the known laws of physics are extrapolated to the highest density regime , the result is a singularity which is typically associated with the Big Bang . Physicists are undecided whether this means the universe began from a singularity , or that current knowledge is insufficient to describe the universe at that time . Detailed measurements of the expansion rate of the universe place the Big Bang at around 13.8 billion years ago , which is thus considered the age of the universe . After the initial expansion , the universe cooled sufficiently to allow the formation of subatomic particles , and later simple atoms . Giant clouds of these primordial elements later coalesced through gravity in halos of dark matter , eventually forming the stars and galaxies visible today . [PAR] [TLE] Primordial nuclide [ SEP ] In geochemistry , geophysics and geonuclear physics , primordial nuclides , also known as primordial isotopes , are nuclides found on Earth that have existed in their current form since before Earth was formed . Primordial nuclides were present in the interstellar medium from which the solar system was formed , and were formed in the Big Bang , by nucleosynthesis in stars and supernovae followed by mass ejection , by cosmic ray spallation , and potentially from other processes . They are the stable nuclides plus the long - lived fraction of radionuclides surviving in the primordial solar nebula through planet accretion until the present . Only 286 such nuclides are known .
What cosmological model for the universe took place approximately 13.8 Billion years ago and is generally understood to be nucleosynthesis in stars followed by mass ejection?
What cosmological model for the universe took place approximately 13.8 Billion years ago and is generally understood to be nucleosynthesis in stars followed by mass ejection ?
Big Bang
Big Bang