On 21 Nov 2012, at 18:51, John Clark wrote:

On Tue, Nov 20, 2012  Bruno Marchal <marc...@ulb.ac.be> wrote:

> both the W-man and the M-man know perfectly well who they are,

Yes certainly they do, they know exactly who they are but they are not the ones that Bruno Marchal asks questions and demands predictions of,

Please just read what I said. If something is not clear, ask a straight question.

The prediction is asked to the H-man. The confirmation can be asled on the H-man when he becomes the W-man, and to the H-man when he becomes the M-man. That is the prediction is asked to a singular you, and the confirmation can be asked to all the obtained "you".

or at least I don't think they are but who knows.

Just read what I say. Consult the paper in case of doubt.

Bruno Marchal wants a mysterious entity called "you" to answer questions,

This is a so boring rhetorical play.

The question is asked to you when you are in Helsinki.

If you prefer, I define John Clark by the owner of your identity cart. the question is asked to John Clark when he is in Helsinki, and concerns the evaluation of the chance he found himself (with its identity cart- having the feeling to be in Moscow.

a entity who, near as I can understand, is the Helsinki man after he ceases to exist, or maybe its the Moscow man before he starts to exist.


In either case the men involved aren't going to be answering many questions, they seem to have developed a speech impediment.

The question is asked in Helsinki. Never after. You introduce unnecessary complications.

> You push on a button, and, as a comp is assumed, you know that when you will open your eyes WHOEVER you will be by the comp assumption, you will see only only once city, and you are asked to evaluate which one.

And Bruno Marchal makes the assumption, that is very obviously wrong, that there is only one "you".

Not at all. I clearly distinguish the 3-view on the 1-view (there will be two 1-view), and the 1-view from the 1-view, which are both unique as a s simple consequence of comp.

> There are no future you in Helsinki, as the body in Helsinki is destroyed.


> So you are the Helsinki man in Helsinki, and then you are the W- man AND the M-man,

OK, but you are asking the Helsinki man to predict NOW not then about what "you" will see in the future, and if in the future "you are the W-man AND the M-man" then obviously "you" will see W AND M.

In the 3-view, but the question bears on the 1-view as seen by the 1- view. by comp you know that you will survive and feel to be unique in once city, and the question bears on that? You come up again and again, with the 3-view on the 1-views, and never take the pain to listen to what each copy is saying. They say "I am in W" or "I am in M", never both.

>> "you" can mean anything

> Precisely: you are all the copies

And yet when a question is asked about what "you" will see Bruno Marchal insists that no ambiguity is involved in the question.

No, by the comp assumption. Nothing is ambiguous. There is just an non ambiguous clear indterminacy. you will feel to be one man in once city, but you cannot predict which one in particular. You can predict only that it will be either W or M, as you can be sure in advance that you will not feel to be both copies at once.

> in the 3-views on the 1-view.

I can conceive of 2 things being identical from the 1-view but not from the 3-view, the biological John Clark and the uploaded John Clark for example; but I can not conceive of 2 things being identical from the 3 view but not from the 1-view,

That simply never happens.

that's why I don't understand your constant complaint that I'm just looking at things from the 3-view.

Because you keep saying that after the duplication you will be in both places. That is correct in the 3p view, but non sensical in the 1p views.

> you are only one person, in all situation,

Who is only one person in all situations? In a world where duplicating chambers exist Bruno Marchal is certainly not just one person in all situations, but John Clark doesn't know about "you".

With QM I am multiplied in more than 10^100+ at each instant, yet there is only one first person view.

> You know that you will survive in one city.

Who knows that what will survive in one city?

You know that from assuming comp and the protocol. You know that you would have survive with probability one in M, if there were no M- reconstitution, and vice versa. But a reconstitution elsewhere cannot influence on the fact that you survive in some places, yet the experiment here shows that it can change the prpbability outcome, and that is part of the point.

>You just don't know which one.


Which city, and which first person experience (living in M, or living in W).

Are you just playing stupid or what? This has been repeated more than once.

After the exact duplication of the body and brain of Bruno Marchal, but before different environments (like seeing different cities) causes changes in them, there is no way for a third party to differentiate between them, and so obviously they themselves can't differentiate between themselves either. And so the two Bruno Marchals are fungible. It would make no sense to ask which one will see Washington, all you can say is that the one that will see Washington is the one that will change into the Washington man, and the other one will not change into the Washington man because he didn't see Washington.

No problem. the question is about which change you will live. the question is asked before the duplication.

Money is fungible too and so if you had $1000 in a online account and transferred one dollar to a online retailer to buy something it would be meaningless to ask which one of those 1000 dollars was transferred, all we can say is that the one that was transferred was the one that was transferred, it's the only thing that's different about it and the other 999, and it only happened after the transfer.

> It is amazing because I have never seen people having a problem with step 3,

Then I have found a very serious error that others overlooked.

No, because you only confuse the 1-you with the 3-you.

> Tell me if you agree with this. suppose that in the WM-duplication you are told that you will have a cup of coffee after the reconstitution is made, in W and in M. Do you agree that you can be sure that "you" will live a drinking coffee experience with certainty?

If Many Worlds is correct then everything that can happen to John Clark will happen to John Clark, but the question was about "you" and John Clark isn't sure about that, not even who "you" is.

No the question is about a result of an experience. you push a button, and you self-localize. You might consider a protocol where the person ignore if the protocol will be able or if he will be send (under anesthesia) after a coin choice between W and M. You talk like if you could distinguish the two protocols, which makes non sense, and this refutes your point, as you have to say "w and M" in the first protocol, and "w or M" in the second. But if the copies never met themselves, there is no way they can distinguish the two protocols.

> > and John Clark is getting impatient at Bruno Marchal when Bruno Marchal just pees on the question because the point of view requested is obviously the point of view of the reader of the thought experiment.

> It is assumed that the reader has the cognitive ability to put himself at the place of the copies, given that the question bears on the future 1-view.

If it's that easy then Bruno Marchal should have no difficulty restating the entire thought experiment without the use of personal pronouns, and if Bruno Marchal is worried that it will be tedious to use the proper noun let's make the name of the experimental subject be "Ed", it's actually one letter shorter than the pronoun "you".

I did it, despite it looks like you are just playing stupid.

> (technically that is what Löbian machine can already do enough to get the point).

And the phrase "Löbian machine" is even more nonstandard than "comp" with a even more obscure meaning.

I gave definition and example. You are quite unfair. The notion of Löbian machine is completely standard, even if due to different context, thay have different names in the literature (the most used one is "sufficiently complex theory/machine-prover so that the machine/ theory own Gödel's theorem can be proved by the theory/machine).

I have explained that it is equivalent with any theory capable of proving p -> Bew('p') for all arithmetical Sigma_1 sentence.

I have explained that a universal machine is Löbian when she knows that she is universal, in some weak sense of knowing.

>> re-express the thing without using pronouns and to hell if it sound choppy, this is supposed to be about philosophy not literary elegance.

> very easy to do if you insist.
> A person

The prospect of giving him a name seems to terrify you; "a person" just won't do because at the end of the day "a person" is who Bruno Marchal will ask questions to and request predictions, and "a person" could be anyone so nobody will know who is being asked. So instead of "a person" let's call him "Ed".

Ed, after the duplication will Ed see Washington?

 Ed, after the duplication will Ed see Moscow?

Ed, after the duplication will Ed see one city and one city only?

Ed, is there a 100% chance that all of that will happen?

Ed, is that a contradiction?
No it is not because ED HAS BEEN DUPLICATED.

You confuse the 3-Ed, and the 1-Ed, that is Ed's body localization, and Eds' subjective experience.

> is in Helsinki and will be WM-duplicated.


> "W" represents "the first person experience

Who's first person experience?

The experience which can be lived by the H-man after its annihilation, duplication and self-localization in the two places. precisely "W" is the one lived by the guy reconstituted in W. You have agree that this can still be called the H-man.

> of seeing W + memory

I'm not sure what W + memory is,

You can easily guess. It is the experience of the one reconstituted in W, and keeping the meory of everything which happened (including its attempt to predict, in H, its present singular experience, in W.

but I'm going to assume it just means W's memory

W is not a person. W is the experience of feeling to be in W. But I see what you want to mean. OK.

> of having been in H"

Oh, you're talking about Ed.

> and "M" represents "the first person experience of seeing M + memory of having been in H".

In other words ED.

> and no first person experience of seeing simultaneously W and M will ever occur

Simultaneously ED has a first person experience of seeing W and only W, AND Ed has a first person experience of seeing M and only M.

Correct 3p view on the 1-Ed.

> How can the person

In other words how can Ed.

> evaluate P(W) and P(M)?

100% and 100%.

You again forget that "W" is for the subjective experience of being in W. In in H you predict noth 100% for both 1-view, both copies will have to say I was wrong, as they lived only the experience of being in one city, and that was what the question was about.

> Once you take the 1/3 distinction into account the pronouns are not ambiguous at.
> You = the H-man, before the pushing.

But in addition to "you" being the Helsinki man Bruno Marchal insists that "you" is also kinda sorta the Moscow man and "you" is also sorta kinda the Washington man,

No. Not kind asort. We have already agreed that both the W-man and the M-man can be considered as both genuine survivors of the H-man. We have to accept this when assuming comp.

so at the end of the thought experiment when Bruno Marchal wants to know what "you" will feel John Clark sorta kinda doesn't know who Bruno Marchal is kinda sorta referring to. The name for that sort of thing is ambiguous.

Only because you keep forgetting the 1 and 3 prefixes.

> The question concerns a prediction of future 1p experience, from the 1p-view,

And what prediction has to do with personal identity is also a mystery to John Clark; memory is what's important not predictions.

1) personal identity is not relevant
2) We can test comp and physics only by comparing their prediction. So "prediction" is crucial.



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