what is causing the world line shifts? is this ever explained?

[hamsterofdeath]

i've reached several endings but haven't gotten an explanation yet

[..]

Not really explained, at least for this vn. If you're willing to read a reddit post---
https://www.reddit.com/r/steinsgate/comments/71b5rv/sg_0_question_about_worldline_changesworldlines/
If you remember the first steins;gate, you know about the alpha and beta worldlines. Certain events that happen causes Okabe to switch between the two, and that's partly because of the different qualities that those worldlines have which, if reached, would cause the shift. That's how I understand it.

For SG0 it seems to be more of just who ends up in control of Kurisu's memories of the time machine, either through kagari or the AI.

[Dashy]

Think of it this way: In the first Steins;Gate we learn that changes to the past cause a shift in worldlines, easy to understand and Okabe Kyouma is the one causing them.
Here, there are many groups, organizations and individuals racing one another for the secret of time travel. Some of the decisions you make, as small as they may seem, have a butterfly effect where they lead some groups to be further ahead on the race, like finding out that Okabe is KEY in all of it, and down the line it will aid them into building time machine prototypes. All of these prototypes fail but they still leave effects on the past, which retroactively affects the present creating an ever so subtle change in worldlines. The reason why it may seem so random is that the whole thing is very unstable with so many different people trying to change it so it just keeps escalating while the worldline tries to stabilize itself.
Basically, do thing in the present, leads to a future were somebody else tries to change the past with varying degrees of success, the change in the past affects your present again causing a temporary or stable shift with minor or mayor differences, Kyouma being the only one capable of understanding a shift happened due to Reading Steiner.
Same concept as D-mails just way more convoluted and not intentionally caused directly by him.

[hamsterofdeath]

but the world line change must happen at the exact moment the past is changed. this can only work of someone else already has a working time machine. if this is the case, then how do my actions matter? i don't see how answering a phone or not can make a difference, given that a world line change happens or does not happen immediately afterwards

[Dashy]

The thing to remember is that those machines are not fully functional, or the changes they produce are not permanent due to not understanding the whole convergence points thing. Much like SERN sending people to the past, but all of them dying due to jellyfication all those groups are doing experiments but they cant quite complete them. Okabe 's actions are key because he knows all that is necesary for it in theory, and the importance of Kurisu's research. Okabe and others are spied on and investigated at various points in the story for different reasons, some conversations and actions lead to changes in the relationships between many people, people finding out each other's secrets or just being unraveled and used.
And the reason so many people are suddenly working on them is due to the Nakabachi papers, that while they were publicly refuted, many scientists considered that there was some truth in that research and started their own from there. The Nakabachi papers were after all a very early draft of Kurisu's research, with some incorrect info mixed in. The failed experiments are ALREADY happening right off the start of the game.
Also, remember Okabe is the only who fully understands and realizes worldline changes, but he has no memory of the worldline he is moving to. I dont think saying the worldline shift happens at the exact time a time travel is made is correct, since if anything it should be said that the change happens in the past rather than the future. Its pretty messy honestly but thats how time travel stories should be, cause and effect all messed up all over the place. Bottomline is that with many people trying to figure out timetravel, Okabe is on the right spot, in contact with the right people, and with the right knowledge to tip the scales, and doing nothing will also lead to the war happening, some bad ends just make it happer sooner

Just my view on all of it, not sure if there are official interviews that set things in stone.

[Sirlion]

A worldline change occurs often, most are minor so not even Okabe can perceive them. BIG shifts take place every time a major world-changing (or ending) event\object\person is possessed by certain groups. The shift occurs when Amadeus and its knowledge is in the hands of a specific organization, thus making said organization ahead of the time machine race.

[hamsterofdeath]

i don't understand it. the world line shift was established to be a result of a change in the past. so how would amadeus being in the clutches of xxx instantly cause a shift?

[..]

I think i understand what you're trying to say. Basically, why does it happen that instant rather than when they actually use the machine to change the past right?
Part of it is an author's decision; there is a bit of inevitability assumed and skipping that may be for the best. Just a thought anyway.

Another is bc those are important moments that change events(change the cause, and you change the results). Because the flow of time is all screwed up, it can be hard to keep up with at times as you are working with a LOT of assumptions. For all i know there could be a sg -1 with future daru pulling the strings.

Anyway, just as how you decided whether to travel back in time or not for suzuha's ending(which ends up altering worldlines), okabe picking up his phone or ignoring it creates a different and significant set of events. In order to effectively display this, okabe shifts to a different worldline depending on what you decide for him. Hope this last part at least answers your q.

[糾う]

Originally posted by ..:

I think i understand what you're trying to say. Basically, why does it happen that instant rather than when they actually use the machine to change the past right?

Because the instant they receive the information in the now, it is already used to create a time machine in the future and affect the past, which in turn instantly changes the present.

[hamsterofdeath]

this explanation contradicts how the shifts work in steins gate (non zero)

[糾う]

Originally posted by hamsterofdeath:

this explanation contradicts how the shifts work in steins gate (non zero)

What do you mean?
It's very similar to the deletion of the first D-Mail.

[hamsterofdeath]

in the original SG, a world line shift occured at the exact moment something was done to change the past.

[糾う]

Originally posted by hamsterofdeath:

in the original SG, a world line shift occured at the exact moment something was done to change the past.

The deletion of the D-Mail didn't change the past directly either. It affected the future where Suzuha came from as to prevent paradox, because it removed the source of SERN's successful time research, thus the convergence of the established future was broken and that affected the past(because of Suzuha being already there) and the present as well, swiching to another attractor field entirely.

Past/present/future all happen together and are calculated "at the same time", the moment they get information about the time machine, their fate is already set in place as no one can prevent them from getting it and that same moment is the source. Their work in the future affects the past which affects the present. The VN doesn't give explicit reasons why some of the switches happen, but everything is tied with Amadeus. We know Okabe is being recorded, so every call and reaction also affects how the others after Amadeus perceive his actions and importance of the project and their knowledge. It is also assumed Okabe's own courage and willingness at the moment can also affect how he acts to the future events, which can explain the difference in the Kagari/Kurisu(where he gets his memories willingly sampled) end split. Each faction has different means and plans of developing their time machine, the world changes according to whoever gets the lead first. It's a mix of paradox prevention and actual changes to the past.

[gaurdianAQ]

I know this is an old thread at this point, but I just want to point out, that if you think about it, deleting the dmail should not have switched them back, I can understand why the first dmail switched them to the alpha attractor field, but at that point the past had been changed, deleting the email in the present shouldn't prevent there time travel research from progressing.

They might wonder why some of their eschelon data is missing, but that d-mail was just the catalyst, it didn't contain key data to SERNS research. It would have been more believable if they had somehow managed to prevent sern from ever catching it with eschelon (like if they could somehow travel back in time to before they received the dmail and prevented rintaro from receiving it)

[Delta]

Originally posted by hamsterofdeath:

in the original SG, a world line shift occured at the exact moment something was done to change the past.

I hope my answer gets to you after all this time and be useful to you.

The way I see it is that it has to do with perspective. In the original SG, we always followed the "present" Okabe. We don't get to see what actually happened between the moment the past was changed and when "present" Okabe arrived to the new world line.

However, we can infer some things based on the present we see.

The important facts of every alpha world line are:
- Kurisu joins the Lab after Okabe claimed she should have been dead. (Evidence in Chapter 10; Kurisu reminds Okabe what he said to her in July 28)
- Okabe and John Titor started sending messages to one another when Okabe thought he was an impostor. (Evidence in Chapter 6; Suzuha knows Okabe's @channel nickname)
- The Lab completes the Time Leap Machine in August 13.

What I am trying to get at with the above facts, is that those could only happen if Okabe remembered in every Alpha WL what occurred in the Beta WL. In other words, in every Alpha WL we see, in July 28, Okabe's memories get overwritten with those of Beta. Therefore, every world line shift will follow the same pattern.

Then, we could say this: if a world line shift leads to more world line shifts in the future, "past" Okabe would only experience Reading Steiner once at the time of the original shift and he would observe the consequences of the future shifts until he gets overwritten with the memories of "present" Okabe. Which, in fact, is what could be happening in SG0, but we don't get to see Okabe being overwritten.

I don't know if I explained it clearly enough. But here is an example of the original SG:

α 0.571015% (lottery numbers world line)
- July 23. Daru receives D-Mail.
- July 28. Okabe gets overwritten with the memories of Beta.
- July 29. Kurisu joins the Lab.
- August 1. Okabe finds the IBN 5100.
- August 3. Okabe gets overwritten with the memories of α 0.571024% (the first Alpha WL in the VN)
- August 4. Moeka sends her D-Mail; WL changes.

α 0.523299%
- July 23. Daru receives D-Mail.
- July 28. Okabe gets overwritten with the memories of Beta.
- July 29. Kurisu joins the Lab.
- July 31. Moeka receives her D-Mail and steals the IBN 5100.
- August 1. Okabe doesn't find the IBN 5100.
- August 3. Okabe gets overwritten with the memories of α 0.571024% (the first Alpha WL in the VN)
- August 4. Okabe gets overwritten with the memories of α 0.571015%

What do we see here? In WL α 0.523299%, from "past" Okabe's perspective, he would arrive from the Beta WL to a WL where Moeka stole the IBN and he doesn't get the computer, but later in that same world line, he will be overwritten with memories of other world lines the "present" Okabe experienced.

I hope this is enough to make it clear; if there's any doubt, I'll try to explain it better.