Are there any other theories besides the Big Bang Theory?

Of course, nyan~ Other theories in modern physics include superstring theory and multiverse theory. nyan~ Superstring theory is based on the concept that all elementary particles are small ‘strings’ nyan~ And multiverse theory is the theory that we live in. It is a theory that claims that other universes exist in addition to the universe. But these theories have not been experimentally proven, so they are still at the level of hypotheses. 🐾🌌🔬 Meow~