On 22 Nov 2012, at 15:55, John Clark wrote:

Bruno Marchal <marc...@ulb.ac.be> wrote:

> ?


> by comp you know that you will survive and feel to be unique in once city,

By comp who knows that what will survive and feel to be unique in one city?

Any human (and Löbian machine) can understand that if comp is true, it means that they will survive and feel unique in one city. That is confirmed by the interview of the resulting copies.

> you cannot predict which one in particular.

What cannot predict which what in particular?

Nobody can predict in which city anyone can feel to be in a WM- duplication, even God.
If God predicts W, the M-guy will understand that God failed.
If God predicts M, the W-guy will understand that God failed.
If God predicts M & W, both guys will understand that God failed.
Only choice: W or M. In that case, both copies can confirm that God was correct.

>> 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.

It violates no laws of physics and happens all the time in the world that you created, the world where duplicating chambers are ubiquitous. If 2 bodies and brains are identical from the 3-view their subjectivity is identical from their own view. If you dispute this give me a counterexample.

I have never dispute this. The question concerns the result of the differentiation brought by the self-localization done after the duplication.

> you keep saying that after the duplication you will be in both places.

John Clark keeps saying that after the duplication John Clark will be in both places.

Not from its personal subjective view (1p). The question bear on this.

> That is correct in the 3p view, but non sensical in the 1p views.

Where subjectivity is concerned if things are identical from a third person perspective they are certainly identical from any first party one. If you think I'm wrong give me a counterexample.

They are not identical. One body is reconstituted in W, and the other in M.

> With QM I am multiplied in more than 10^100+ at each instant,

John Clark is and Bruno Marchal is, but as for "I" that depends on who "I" is.

So you agree now that the situation is equivalent, with respect to probability, for QM and comp?

> you are only one person, in all situation

Who is only one person in all situations.

All person when they refer to their subjective 1p.

> there is only one first person view.

There are over 7 billion first person views on this planet, and growing.

Yes, but they are all unique from their first person point of view.

> You know that you will survive in one city.

Who knows that what will survive in one city?

See above.


> Which city, and which first person experience

Which first person experience?? Until one duplicate sees Moscow and the other duplicate does not the two brains produce first person experiences that neither a third party nor the first party itself can distinguish between; and if there is only one thing it's nonsensical to ask "which one?" about anything.

Again, what you say is obvious, and non relevant. the question is asked to the H-man, about which city he will see after pushing the button, *and* opening the door (localizing himself).

> the question is about which change you will live.

Which change who will live?

Who? Anyone doing the experience fully described in step 3.

> you only confuse the 1-you with the 3-you.

John Clark believes it is Bruno Marchal that is confused because Bruno Marchal seems to believe that it is easier to produce things that are identical from the 3 view than from the 1 view, when in fact the opposite is true.

> you self-localize.

"You" don't do anything, the location does something to "you", the city causes a change in "you" that is not made in your no longer exact twin so now a third party could distinguish between the two, and now it's possible to do what could not be done before "you" can tell that its twin is not "you".

And so a selection has occured, let us say in Moscow, and the H-guy knew this in advance, so the question asked in Helsinki made sense, and he understand that he could have guess in advance that he would have been the M-guy. Nor can anybody predict a WM-sequences in the iterated case, as most of them are random-incompressible.

> 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,

I don't even understand what you're saying, read the above and see if you do.

OK, I was unclear.

Consider the following two protocols:

1) In Helsinki you are put under anesthesia, then sent to W or to M, according to a random coin choice. You wake up in a room, open the door and see that you are in a city.

2) same protocol as in step 3, except that the annihilation is done when you are under anesthesia.

And now consider the following third protocol. You are in Helsinki, and you are told that we will repeat ten times, either the protocol 1, or the protocol 2, but without telling you which one.

The question is, can anybody coming back from such an experience decide if the protocol 1 has been used, or if the protocol 2 has been used. We suppose that in case the protocol 2 has been chosen, the copies have no means to see each other.

> The notion of Löbian machine is completely standard,

About all Google knows about "Löbian machines" is what's said about them on this very list, mostly by you.

I use that name in place of "sufficiently strong theory" which is often used in the literature. The very fact that you are doing remark like that show that you agenda is just being negative about me, and that you are not interested neither in the mind-body problem, and still less in the comp mind-body problem and its reduction to a body problem in arithmetic.

I call them Löbian because it can be proven that their probability predicate obey to Löb's formula ([]([]p->p)->[]p). It means that theor beliefs are close for the Löb's rule: if ever they prove []p->p, for some p, they will believe p. That formula is counter-intuitive, but by replacing p with f, or with "0= 1" you can easily see (if you know propositional calculus) that it entails Gödel's second incompleteness theorem. More importantly, Solovay's theorem shows that the Löb formula is the main axiom of the modal logic characterizing the provability predicate of all theories or machine whose theorems or beliefs extends effectively the theorem of Peano Arithmetic (say). I model "believability" by "provability", which makes sense in the case of ideally correct machines.

>> 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,

If I've got the 3-Ed right the 1-Ed is too, and the 3-Ed looks right to me.

If you got the 3-Ed right, you might have got the 3-view on the 1-Ed right, but not their personal 1-view on those 1-view, as they are unique.

> "W" represents "the first person experience

Who's first person experience?

Of the guy opening the door and seeing W. That is one of the Helsinki guy, after he pushed on the button and did the self-localization.

>> 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.

Please give John Clark an example of a correct 3p view of the 1-Ed but the incorrect 1-Ed from Ed's own point of view.

"John Clark feels to be only in M". This is not correct for the 1-Ed feeling to be only in W.

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

>> 100% and 100%.

> You again forget that "W" is for the subjective experience of being in W.

I've forgotten nothing and the probability the ED will have the subjective experience of being in Washington is indeed 100%.

This is refuted by the 1-Ed in M.

he can decide to ascribe consciousness, and even Ed-identity to the doppelganger, but that is not the same as his current personal feeling, and the question was about that person self-localization feeling.

I see only hand waving to deny the obvious.

> both copies will have to say I was wrong

Ed will say that he (Ed) is experiencing Washington just as Ed predicted and Ed will say that the fellow in Moscow has as much a right to call himself "Ed" as I (Ed) do and he (Ed) is experiencing Moscow exactly as Ed predicted.

But the question was not about the felling of all Ed, but on all personal account to it. You confuse, like in the first post: -"I feel to be in M and I know intellectually that my doppelganger feels to be in W" with -"I feel to be in W and I know intellectually that my doppelganger feels to be in M"

The guy in Helsinki knows in advance that such feeling are incompatible, exclusive.

> We have already agreed that both the W-man and the M-man can be considered as both genuine survivors of the H-man.

And yet Bruno Marchal insists the H-man will not see W and M.

I say that from the first person perspective the H-man will see W, or will see M. He will not see both W and M, from the first person perspective.

It looks like you just don't hear the simple question asked.


Two different things are happening to two different things and because that can't be described as one thing happening to one thing Bruno Marchal is claiming a new and profound type of indeterminacy.

John K Clark

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