Question

what is big bang theary​

Answer 1

The Big Bang theory is the cosmological model for the observable universe from the earliest known periods through its subsequent large-scale evolution. ... 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.

Answer 2

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The Big Bang is the name that scientists use for the most common theory of the universe, from the very early stages to the present day. The universe began as a very hot, small, and dense superforce (the mix of the four fundamental forces), with no stars, atoms, form, or structure (called a "singularity").