Physicists and cosmologists are uncertain about the ultimate fate of the universe, particularly regarding concepts like Dark Energy and potential scenarios such as a new Big Bang after heat death. The discussion highlights the limitations of current understanding, emphasizing that the question of what existed before the Big Bang remains unanswered. Participants express frustration over repeated inquiries into this topic, reiterating that the concept of "before" the Big Bang is fundamentally flawed since time itself did not exist. The consensus is that definitive knowledge about the universe's end is elusive, leading to the conclusion that the question may not even be properly posed. The thread concludes with a reiteration of the uncertainty surrounding these cosmic questions.