The conversation between human and AI assistant.
How should we treat the question what caused the big bang if time started only after the big bang?
How can these theories be tested or proven?
Many of these theories involve concepts that are difficult to test or even observe such as extra dimensions or singularities. However, some theories such as the cyclic model may leave imprints on cosmic microwave background radiation or gravitational waves. So, scientists are constantly searching for evidence to support or disprove these theories.