Talk:The Hourglass/@comment-5782071-20150516222115/@comment-27304481-20151217223551

They could not have done this, due to the Novikov Self-Consistency Principle. The past is gonna stay the same no matter what, basically. The principle states the universe always makes the past stay the same,,as shown in this episode. The moment they walked into the sea shrine, the hourglass activated and created a small time loop, just setting itself up so the actual timeline can take place. Ultimately, the hourglass is really more effectively a way to give any gem future vision, except certain future vision, like sapphire.