The Big Bang theory is an effort to explain what happened at
the very beginning of our universe.The Big Bang theory is the prevailing
cosmological model for the universe from the earliest known periods through its
subsequent large-scale evolution According to the standard theory, our universe
sprang into existence as singularity around 13.7 billion years ago.After the
initial expansion, the universe cooled sufficiently to allow the formation of
subatomic particles, and later simple atoms. Giant clouds of these primordial
elements later coalesced through gravity to form stars and galaxies.
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