Some ideas are:
- You branch off into another timeline and your actions make no difference to the previous timeline
- You’ve already taken said actions but just didn’t know about it so nothing changes
- Actions taken can have an effect (so you could suddenly erase yourself if you killed your parents)
- Only “nexus” or fixed events really matter, the timeline will sort itself out for minor changes
- something else entirely
Like in Black Science, I think time travel would fuck with the fabric of reality. Make it shreddy.
I do not believe in nexus events; there is a personal reason (experience ) I don’t expect anyone else to believe based on something I experienced but I don’t. ETA: Unfortunately, everything has happened already, and I was very angry about it.
Just watched Arrival again yesterday and that’s my other guess. More like your choice of “you have already done it, you can’t alter the timeline” but can’t go outside your lifetime, time doesn’t work the way we think and we can perceive other “times” because they aren’t really linear, just some quirk of our perception makes it seem that way, you really exist concurrently all along your existence.
But if some machine was designed to take you before or after your lifetime, it would tear at the fabric of reality (lifetime not exactly the correct word but your existence that has a beginning and end of some sort).