He meant because the present Chen traveled to the future, so if Yukari of the future didn't return her to the past (present), then there will be no present Chen to make it to the future. So Ran and Yukari right now will lose Chen until the present Chen travel to their time in the future, thus making only 1 Chen at the time.
However, by being one in the future, Yukari knows exactly that the past Chen must be returned, since she has now 2 Chen and remembers the event when she in the future jumped out of a gap to give her past self Chen back.
ForteGVN said: He meant because the present Chen traveled to the future, so if Yukari of the future didn't return her to the past (present), then there will be no present Chen to make it to the future. So Ran and Yukari right now will lose Chen until the present Chen travel to their time in the future, thus making only 1 Chen at the time.
However, by being one in the future, Yukari knows exactly that the past Chen must be returned, since she has now 2 Chen and remembers the event when she in the future jumped out of a gap to give her past self Chen back.
This assumes a deterministic single timeline, with a single, "fated" outcome, however.
It is alternately hypothetically possible for a parallel/divergent dimension/timeline to be spawned at the point in time to which Yukari traveled back through time, which would more neatly wrap up the problems of how that foreknowledge of the future would not change the future and create time paradoxes - by simply making an entirely different timeline at the instant that you travel back in time. (This, incidentally, also clears up the "Grandfather Paradox" by making the time you travel back to not the timeline you came out of, so you're free to kill your own grandfather.)
Ah, thank you, so if present Chen was not returned, then there wouldn't be present Chen to turn into future Chen? Does that mean (if she wasn't returned) Chen disappeared from the world in time between time travel?
NWSiaCB said: This assumes a deterministic single timeline, with a single, "fated" outcome, however.
It is alternately hypothetically possible for a parallel/divergent dimension/timeline to be spawned at the point in time to which Yukari traveled back through time, which would more neatly wrap up the problems of how that foreknowledge of the future would not change the future and create time paradoxes - by simply making an entirely different timeline at the instant that you travel back in time. (This, incidentally, also clears up the "Grandfather Paradox" by making the time you travel back to not the timeline you came out of, so you're free to kill your own grandfather.)
That is possible, yes.
However by making a parallel timeline, the future Yukari had cut off the connection of the present's timeline from its original path. She, knowing this or not, is now the reason why everyone in her past has gone into somewhere they never meant to. It is like the railroad, one train is going from London to Bristol, but someone infiltrates in Birmingham and threatens the officials, so the train will now travel to Manchester instead. The train is there, there is nothing wrong with the train, it's just going to Manchester with a new, unexpected passenger.
This new timeline will not be applied by the rule that "never the selves shall meet", since the future and the present didn't and won't have the memory conflict whereas they meet themselves or they do something they precisely didn't. Those memory got destroyed before they were born, because of future Yukari made a paralel timeline, not using the original one.
This, again, affects directly to their future, which is her present. By being in the changed past, she may avoid the sudden crash of her time, but that would make her an individual that has no origin whatsoever. She can't go back to her time, since it never existed. She can only be with present Yukari and thus making a new future where Gensokyo will have 2 Yukari (and 2 Reimu) existing together. Unless she chooses to go to a new dimension again.
ForteGVN said: However by making a parallel timeline...
Well, that's part of the point of divergent timelines - there are now two futures, the one that the time-traveler departed from, and the one created by the divergence in the timeline.
Hypothetically, there could be a choice involved, you could either go to the future/present you came from, in which case, the changes you made to the past would have had little to no point, but your history would be preserved. It would be essentially nothing more than a temporary visit to a parallel dimension, and nothing more. Even more hypothetically, if we go into Stargate territory, this would enable our time travelers to go back in time to create an alternate dimension where they do something to screw over that dimension and loot it for their own dimension.
Alternately, the time traveler could abandon their own history and past, and go into the new future they created, but it would be one where, when they got there, there would be either a different version of themselves waiting for them, or they were never born, and they would be a person out of place (and to their own world, they will have just disappeared one day and never returned).
Aside from the potential problems of an exponentially exploding number of alternate dimensions, whatever they may be, on the fabric of reality, the concept cleanly removes all time paradoxes from occurring. (And then we get into the Bokurano territory of BS sci-fi ways in which we sweep up all the excess dimensions...)
NWSiaCB said: Well, that's part of the point of divergent timelines
I think your theory is similar to mine. However, in this comic, it's the original past of Yukari to be changed. Thus there is only one future possible and not two. Unless you mean the "present" that future Yukari traveled back was actually the parallel dimension from the first place and not her original one.
If that is the case, then we're simply having Yukari from a different future which shared the same path with this one. So what she made is a change of fate of the present Yukari's timeline and not hers. So she can travel back to where she belongs.
Because if she makes no difference in the past so the future remains intact, then it once again goes back to the single timeline dimension.
Yukari: "I recall meeting myself from the future in the past and she did this and that and that other thing. So to make sure I won't screw anything up I'll have to do that shit."
ForteGVN said: Those memory got destroyed before they were born, because of future Yukari made a paralel timeline, not using the original one.
This, again, affects directly to their future, which is her present. By being in the changed past, she may avoid the sudden crash of her time, but that would make her an individual that has no origin whatsoever. She can't go back to her time, since it never existed.
Hm, but yukari can open a gap and just pop her head or something, without fully crossing.
In the previous page, second koma, she only sticks her hand out. What if she just did that, and then pull her hand back and closed the gap? doesn't that means she would have returned to her own time?
I personally see a Highlander joke. Occam's Razor, yo. :P
Ran-shama!Who is this beauty?Yukari-sama of the futureNot at all.
This will be better than before.
I mean it.Yukari-sama of the futureI'm giving her back. Having an extra Chen around was a real pain for us...Chen!Ran-shama!Try and visualize. When there are two Chens...More importantly, here, something you lost.Yukari-sama of the futureYukari-sama of the futureYukari-sama of the presentAh! It's me!Never mind doubled, our troubles are squared.RAN ON VERGE OF DEATH COME HOME NOWStock gag of typical emergency telegram message from back in the day.How so? Ran should be able to take care of two Chens, right?Meow!Yukari-sama of the presentHeaven State!!Yukari-sama of the presentEw, gross. That would be bad news.
