Big Bang

Physical theory of the cosmos

The Big Bang is a physical theory that describes how the universe expanded from an early state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, the redshift of galaxies and the large-scale structure of the universe. The observed uniformity of the universe, which leads to the horizon and flatness problems, is explained through cosmic inflation: a phase of accelerated expansion during the earliest stages.

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