The conversation between human and AI assistant.
Did the universe really start with the Big Bang? What if another universe existed before it?
That's fascinating. What evidence do we have for the Big Bang theory?
There is a lot of evidence to support the Big Bang theory, including the cosmic microwave background radiation, the abundance of light elements in the universe, and the observed redshift of light from other galaxies. All of these pieces of evidence point to a hot, dense, and rapidly expanding universe at the beginning of time.