We know about Alduin and the kalpa. First, what is Alduin supposed to do? Devour souls right? But then, who is going to clean up the matter and energy left in mundus? Alduin? I find that hard to believe. So what is going to happen with matter and energy?
P.S. : (Sorry if I make any mistakes! I'm on new territory so there are chances that I'll walk into a few rocks while wandering around. If I do, please correct me.)