The big bang theory started the universe. the universe was first filled with cool particles. then when the particles started to like crash to each other they started to heat up. then many explosions happened thus making the universe
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This theory is stated by scientist by saying that the universe is created by a big explosion in the space and they say that the universe is once,is a dust and nebulae in space,forming clumps and compress each other and created a big explosion that created the universe.This is not yet proven because of lack of information about the space and the universe.
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