I was referring to things like Nacirema, btw.
That is a really good point. Would an alternate-universe me be the same me as me?
Define "alternate universe" though.
Like a many-worlds interpretation? Why a branching universes instead of an overlapping phase space?
As it is, if you've seen those .gifs of a tesseract rotating and got the general idea that the extra dimension, in/out, ana/kata, w-/w+, whatever term, is the one where the rotation which looks like it is deforming the shape takes place, but that all sides are always the same size and shape, it's just that rotating through that extra dimension isn't a thing we're good at seeing, right?
Ok, now take a dot and inflate it into a sphere, then rotate it like those tesseracts so it kinda resembles a ball wearing a conical hat <o and realize that if you slice a 3-D sphere out of that 4-D shape you get a sphere, and if you were a piece of that shape looking at it from the inside you would observe a spherical volume around you which seemed to originate in a very small dense state and is expanding.
Your brain is a tool that slices the 4-D universe into a 3-D shape you can observe and interact with by organizing those slices into a pattern by which you can note changes from one slice to the next. One may ask why it doesn't organize them and provide a sense of awareness which proceeds into the past, and that is a good question, but there are less ways to make use of an overall tendency for entropy to decrease I expect, than the various methods by which local decreases against an overall trend of increasing entropy can lead to useful results.
It's rather silly all in all, the moment I am typing this existed just like the moment in which you were writing the post I am responding to. The difference was that we couldn't see it
from those earlier moments, but I was able to see it recently, and my slicing tool imparts a sense of continuity that tells me I saw that moment recently.
Generally there are lots of animals that possess this ability to, how would you put it...
remember things that happened recently. There are some which can anticipate things that will happen soon.
There are not many which can know that those moments in the future, just like this one, exist in the same sense as those earlier moments I was discussing before. The way basic awareness works here just isn't set up to need that information, even ours has to be reminded of the fact that time is not a process, it is not a thing that happens,
it is the direction along which events can be said to happen but even then language isn't well suited for it.
Extending that to another region of spacetime which is almost exactly like our own but doesn't overlap our own requires a rather tortured explanation for why that other region wouldn't have it's own shape, rather than being an almost-copy of ours.
Assuming we went past some Asimov point into full on tech=magic territory and could bud off universes exactly like our own at the moment of budding but which aren't constrained to unfurl beyond that point, then the you in that universe would have the same sense of continuity that you feel right now, except right now I'm going to close my eyes and type a key after hitting enter twice:
g
In the other universe I hit o or something, so there is another you which saw this same post with an o where that g is, are they still you?