MWI experience of created worlds

[entropy1]

Would this be correct: in MWI, if a binary measurement is made, the world splits, say in world A and B. Is it then correct to say that you experience both A and B, but that the experiences of A and B become separated?

 

[PeterDonis]

Is it then correct to say that you experience both A and B, but that the experiences of A and B become separated?

There is no good way to describe what the MWI says happens to your experience using ordinary language. The problem is that words like "you" and "experience" can't possibly mean in the MWI what they mean in ordinary conversation. In the case you describe, there will be a "you" that experiences A and a "you" that experiences B, and both of these "yous" will be "descended", physically, from "you" before the measurement. But are they "the same" you, having both experiences? There is no good answer, because the underlying assumptions behind our ordinary concept of "the same" are not valid for this case.

 

[entropy1]

There is no good way to describe what the MWI says happens to your experience using ordinary language. The problem is that words like "you" and "experience" can't possibly mean in the MWI what they mean in ordinary conversation. In the case you describe, there will be a "you" that experiences A and a "you" that experiences B, and both of these "yous" will be "descended", physically, from "you" before the measurement. But are they "the same" you, having both experiences? There is no good answer, because the underlying assumptions behind our ordinary concept of "the same" are not valid for this case.

If there is a "me" in the ordinary sense, and there is, there must be a "me" in any world, right? Perhaps just not "the same" ones. So indeed the question arises if it is still "me" when brached off; is that what you mean?

The alternative is that "me" is an illusion altogether, perhaps generated by the brain.

If I adopt MWI, I would be happy to adopt that the "me" I know already branched many times in my life. Still I am "me" and I see no reason to believe my branched-off versions are not too.

I wonder if I am still abiding by the forum rules with this post .

 

[Grinkle]

I wonder if I am still abiding by the forum rules with this post .

IMO your question is interesting and also more philosophy than physics.

Here is tongue-in-cheek reference for your perusal. ;-)

S7:E11

https://en.wikipedia.org/wiki/Parallels_(Star_Trek:_The_Next_Generation)

 

[PeterDonis]

the question arises if it is still "me" when brached off; is that what you mean?

That's part of it, yes. Each "copy" of you in different branches has a different set of experiences and memories. So if "you" are defined by a particular set of experiences and memories, then the copies can't possibly all be "you". Different people have different opinions on this, and there is no way to resolve the question by experiment because it's not a question of physics, it's a question of definitions.

The alternative is that "me" is an illusion altogether, perhaps generated by the brain.

This isn't an alternative; it's a different way of describing the same physics. As far as the physics is concerned, the brain is the physical system involved.

 

[Demystifier]

Would this be correct: in MWI, if a binary measurement is made, the world splits, say in world A and B. Is it then correct to say that you experience both A and B, but that the experiences of A and B become separated?

I like to think of it as being analog to biological twins. The other copy is not you.

 

[entropy1]

I like to think of it as being analog to biological twins. The other copy is not you.

The problem I see with that is, to be consistent, the copy you are now is not you too.

 

[Demystifier]

The problem I see with that is, to be consistent, the copy you are now is not you too.

Why not?

 

[entropy1]

Why not?

Because the math handles all copies equivalently, I suspect.

 

[Demystifier]

Because the math handles all copies equivalently, I suspect.

So? How that differs from biological twins?

 

[entropy1]

So? How that differs from biological twins?

Good point.

So I now think of this, given a "biological" world-twin: they are both "me" (from their own vantage point) and they are both 'biological' twin of the other one(s) (from the other one's viewpoint). This seems satisfying to me, for this seems to hold for all copies.

 

[PeterDonis]

to be consistent, the copy you are now is not you too

Yes, it is, because the word "you" (or "me" when you are speaking of yourself) refers to whichever copy is engaging in this discussion, and only one copy is doing that. That's one of the things about ordinary language that makes it unsuitable for describing these kinds of situations: pronouns like "me" and "you" are indexical--which entity they refer to depends on who is using them and in what context.