Board Thread:Off Topic/@comment-29646689-20180430203301/@comment-26877467-20180502003325

tl;dr Order 117 means interplanetary pandemic and everyone has to die

So let's say that you accidentially broke the urn of your great-great-great-grandfather's ashes. Oh no! Now the ghost of your great-great-great-grandfather is going to haunt you! Luckily, you have a time machine! So you hop in that before the ghost of your great-great-great-grandfather can start scolding you, and you travel back to before you broke the urn of your great-great-great-grandfather. You tell your past self to be more careful around the urn of your great-great-great-grandfather. So when you are warned, the urn doesn't break, but if you are not warned, then you break the urn. You're going about your day ↓                 ↓       You are warned by  ←  → You keep going about a future self! \/        your day ↓           /\            ↓       You do not break   /  \   Whoops! You broke the the urn      /    \         urn! ↓        /      \          ↓       You don't warn  /        Time travel to warn your past self               past self Since you didn't break the urn, you have no problem to fix anymore, and no reason to time travel to fix the problem. Which means that you would have not warned your past self, and you wouldn't have been careful around the urn, meaning that you break it, and a loop is generated. There are multiple theories onto how time travel would work in this scenario. One of which is where you time travel back, change something, and time treats the loop as a function. If the loop is different each iteration, then time will evaluate the loop an infinite amount of times, and if the loop ever approaches some stable, repeating instance, then that's what the timeline gets set as. This is called the Limit Theory, named after the Limit operator where the true timeline chosen is the limit as the iteration approaches infinity. For instance, if you send your past self a note saying "Send your past self a note with this number +1" and a number written on it, then in the first loop you'll recieve a note with the number 1 on it, and in the second loop a 2, and in the third a 3. A shmillion loops in, however, the result stays the same as you can't be bothered to fit the next number on the note, and you either send the same number back, or send a note saying "number too large", or don't send anything at all, the point is that all loops after that will be the same. Time inserts the infinitieth loop as the true timeline and continues moving into the future. Another theory is called the Parallel Universe Theory, where each instance of time traveling to the past creates a parallel universe from the point of traveling back to. So if you were to travel back a day, then at the point you traveled back you would have split the universe in two. E            Tertiary timeline, effect of the second / --o-Secondary timeline, effect of the original, \                                cause of the third Original timeline, cause of the Second E Any action performed in a parallel universe has no effect on the original, and therefore sustains causality, and is safe. If you time travel again in a second timeline, then from the same point as before the universe gets split again. If, in all timelines, you time travel, then there will just be an infinite amount of universes coming from that one point, all being the cause of the next and the effect of the previous (except for the original, which is the cause of the timeline before it). In this theory, however, it is impossible to return to another timeline. So in order to deal with the guilt of causing everyone you know much distress in the original timeline, since you disappeared to time travel into another timeline, you can just create an infinite amount of timelines where you do exist by sending your non-time-travelled self to the next timeline and keeping your time-travelled self in the timeline they time travelled to. Then almost all of the timelines will have had you still in them.

Now what would each of these theories do in the scenario shown above? For the Limit Theory, there is no limit for the timelines to approach, the timeline is alternating between two possibilities an infinite amount of times. So what happens if there is no limit? We don't know. Time would probably run into an error and the universe would either be destroyed or would just lose its time dimension. In the Parallel Universe Theory, no bad effects would happen. In fact, there would only be two timelines: The one where you time traveled away and left all your friends and family to wonder what happened to you, and the other where you got stranded and warned your other self. There won't be an infinite amount of universes since you don't time travel in the version where you were warned (unless you want to make an infinite amount of universes where your friends and family are not freaking out over your disappearance and by ease your guilt with the statistical shred of wobbly reassurement that you didn't abandon them in ~100% of the parallel universes)

If, in the Parallel Universe Theory, there is something that prompts you to time travel each time but still have instances alternate, such as passing a note to your other self saying "If this note says "1," write "0," and vice versa," then there will be an infinite amount of parallel universes that just alternate between the 1 and the 0 between each instance, but the universe will be safe.