Cold Big Bang is a designation used in cosmology to denote an

absolute zero Absolute zero is the lowest limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as zero kelvin. The fundamental particles of nature have minimum vibration ...

temperature at the beginning of the Universe, instead of a (hot)

Big Bang The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

. In an attempt to understand the origin of

atoms Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, an ...

, Georges Lemaître proposed (by 1927) that before the

expansion of the universe The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. The universe does not exp ...

started all the matter in the universe, it formed a gigantic ball of nuclear liquid at very low temperature. This low temperature was required to provide an adequate cohesion within the Lemaître's primeval atom. In 1966,

David Layzer David Raymond Layzer (December 31, 1925 – August 16, 2019) was an American astrophysicist, cosmologist, and the Donald H. Menzel Professor Emeritus of Astronomy at Harvard University. He is known for his cosmological theory of the expansion of ...

proposed a variant on Lemaître's cosmology in which the initial state of the universe was near

. Layzer argued that, rather than in an initial high entropy state, the

primordial Primordial may refer to: * Primordial era, an era after the Big Bang. See Chronology of the universe * Primordial sea (a.k.a. primordial ocean, ooze or soup). See Abiogenesis * Primordial nuclide, nuclides, a few radioactive, that formed before ...

universe was in a very low entropy state near absolute zero. The mainstream version of the Cold Big Bang model predicted an absence of acoustic peaks in the cosmic microwave background radiation and was eventually explicitly ruled out by WMAP observations.

References

External links

Universe: Cold Big Bang
- Cosmos Portal Big Bang {{physical-cosmology-stub