Big Bang

Epic card · No. 7541

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. Detailed measurements of the expansion rate of the universe place the cosmic inflation at an estimated 13.787±0.02 billion years ago, which is considered the age of the universe. A wide range of empirical evidence strongly favors the Big Bang model, which is now widely accepted. Extrapolating this cosmic expansion backward in time using the known laws of physics, the models describe an extraordinarily hot and dense primordial...

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