If you had a machine that created a window through which you could see the future, and in the future you wrote down the winning lottery numbers and relayed that information to your present self before that lottery number was drawn.
However, in your present selfs excitement, you turn off the machine before your future self wrote the winning lottery numbers into it for your past self.
What would happen?
Apologies, I copied and pasted the answer below from another reply I made elsewhere in this thread
==
I’m not talking about about the possibility of real infinite dimensions. I’m talking about sci fi, and stories, which is the context of the OPs question.
In a “real” scenario, the experience that matters is the one I’m having, not the one other versions of me might be having.
But in a story, there is no “true” timeline, or a more “real” timeline. They’re all being retold to us indirectly, and the choice of the version of the person retelling those experiences is arbitrary by the author. It doesn’t matter what perspective the author chooses, because every other outcome also happened, the author just didn’t tell us those stories.
I think the disconnect here is between objective and subjective meaning. In an infinite multiverse, ‘reality’ isn’t a singular objective truth—it’s a collection of subjective experiences. But that doesn’t erase meaning; it just means meaning is something we assign, not something inherent.
You’re right that if every possible outcome exists, no single timeline is ‘objectively’ special. But in fiction (and arguably in reality), what matters is the perspective we focus on. A story isn’t weakened by the existence of other timelines—it’s strengthened by the fact that, out of infinite possibilities, this particular one is being told. The act of choosing a narrative is what gives it weight.
It’s the difference between nihilism (‘nothing matters, so why care?’) and absurdism (‘nothing matters* inherently, so we get to decide what does’). A multiverse doesn’t have to make things meaningless—it can highlight how rare and significant certain choices are, precisely because most versions of a person might not make them (e.g., Invincible).
I get the sense you’re resistant to this because it feels like it undermines objective meaning. But what if meaning was never objective to begin with?
Think of it this way.
“I went back in time to save my family” in an infinite timelines story means that going back in time spawns in infinite number of worlds that didn’t exist before, in which the family doesn’t make it, and an infinite number in which they do. And not a single one of those families is the “real” family of the person who went back in time.
The fact that the author choose to focus on one perspective in which it seems like the time travel has made a difference, doesn’t change the fact that it didn’t make a difference, and the family they were trying to save is gone. The infinite copies weren’t “saved” from anything, because there are infinite versions that weren’t.
The only way to tell a meaningful story in that situation is to create situation where the actions of jumping back in time alter the future of the person jumping back in time. And that means you either suck up the paradoxes, or you write a clever story in which the paradoxes are neatly accounted for before they ever occur (or you write a closed loop story)
Edit - Or you could tell a non infinite loop story, where a single universe is spawned by the act of jumping back in time. That still won’t save the “real” versions of the family you jumped back to save, they’re still gone, but at least it creates only a single version of them that the character can save.