Search results
Results From The WOW.Com Content Network
The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. [1] The notion of an expanding universe was first scientifically originated by physicist Alexander Friedmann in 1922 with the mathematical derivation of the Friedmann equations.
This timeline of the Big Bang shows a sequence of events as currently theorized. It is a logarithmic scale that shows 10 ⋅ log 10 {\displaystyle 10\cdot \log _{10}} second instead of second . For example, one microsecond is 10 ⋅ log 10 0.000001 = 10 ⋅ ( − 6 ) = − 60 {\displaystyle 10\cdot \log _{10}0.000001=10\cdot (-6)=-60} .
Diagram of evolution of the (observable part) of the universe from the Big Bang (left), the CMB-reference afterglow, to the present. For the purposes of this summary, it is convenient to divide the chronology of the universe since it originated, into five parts.
The theory he devised to explain what he found is called the Big Bang theory. [citation needed] In 1931, Lemaître proposed in his "hypothèse de l'atome primitif" (hypothesis of the primeval atom) that the universe began with the "explosion" of the "primeval atom" – what was later called the Big Bang.
The timeline of the universe begins with the Big Bang, 13.799 ± 0.021 billion years ago, [1] and follows the formation and subsequent evolution of the Universe up to the present day. Each era or age of the universe begins with an "epoch", a time of significant change. Times on this list are relative to the moment of the Big Bang.
The "Big Bang" scenario, with cosmic inflation and standard particle physics, is the only cosmological model consistent with the observed continuing expansion of space, the observed distribution of lighter elements in the universe (hydrogen, helium, and lithium), and the spatial texture of minute irregularities (anisotropies) in the CMB radiation.
Big Bang and Hartle–Hawking State diagram. The Hartle–Hawking state, also known as the no-boundary wave function is a proposal in theoretical physics concerning the state of the universe prior to the Planck epoch. [1] [2] [3] It is named after James Hartle and Stephen Hawking.
The time-line in this schematic diagram extends from the Big Bang/inflation era 13.7 Byr ago to the present cosmological time. Observations announced in 1998 of distance–redshift relation for Type Ia supernovae [ 5 ] indicated that the expansion of the universe is accelerating, if one assumes the cosmological principle .