Re: Rép : Thought Experiment #269-G (Duplicates)

From: Bruno Marchal <marchal.domain.name.hidden>
Date: Mon, 11 Jul 2005 12:52:51 +0200

Le 10-juil.-05, à 04:11, Lee Corbin a écrit :

> Bruno writes
>
>>>>> You are asked to bet on your immediate and less immediate
>>>>> future feeling. Precisely: we ask you to choose among the
>>>>> following bets:
>>>>>
>>>>> Immediate:
>>>>> A. I will see 0 on the wall.
>>>>> B. I will see 1 on the wall.
>>>>> C. I will see 0 on the wall and I will see 1 on the wall.
>>>>> D. I will see 0 on the wall or I will see 1 on the wall.
>
>> As I said I have no problem with accepting Lee = Lee' = Lee''
>> (although
>> I think this will entail Lee = Bruno at some point, but I have no
>> problem with that and we can come back to this notion later). But I
>> was
>> not argumentating on personal identity, only on the problem you face
>> when predicting your immediate future (or less future) experience. It
>> is a different matter.
>
> You asked me to *predict*. I did.


I asked you to predict your immediate first person experience, not a
bird's view of the situation. This explain why if I'm in good move you
just win nothing, and if I'm in bad mood you and all the Lees own me
five dollars!



>
>> I duplicate you iteratively, by annihilating (painlessly!) you and
>> reconstituting you in the 0-room and the 1-room which differs from
>> having a 0 (resp. 1) painted on a wall. And I let you choose between
>> the bets A, B, C, D described above.
>>
>> You choose C, that is: "I will see 0 on the wall and I will see 1 on
>> the wall".
>> Now, as I said this is ambiguous. So if I am in a bad mood, asking the
>> first 0-Lee' about its immediate apprehension if he answers me "I am
>> seeing 0 and I am seeing 1" I consider it as false (0-Lee' sees only
>> 0!), and the same for the other Lee, so all the 2^n Lee must give 5$.
>
> Now you are asking an instance a question (since there are
> two of me), and it seems that you are playing on the ambiguity
> of the term "you". When you ask an instance---now, *after*
> the copying has been done---whether he is seeing a 1 or seeing
> a 0 or seeing both, he has to stop you (I mean I have to stop
> you) and ask exactly what kind of information you are after.
>
> Clearly, if you are talking to one instance (so far as that
> instance knows) he'll say that he is seeing a "1" or he will
> say that he is seeing a "0". This is because he'll take the
> usual meaning of terms.

OK.

>
> When you then inform him that he has actually been copied and
> that there is another instance of him in the other room, then
> naturally he should say "Okay, here I am seeing a "0" and in
> the other room the opposite."

Precisely: here I see without much doubt a 0, and I believe
intellectually, by trusting you, that another Lee see the opposite in
the other room. Do you agree it is very different sort of knowledge?
The question was concerning the first notion of knowledge.


>
> We know all the facts. What we want are two things: (1) we want
> to speak clearly. (2) we want to know whether or not to regard
> our duplicates as selves.

(2) is another thread. It is an interesting question, but it has
nothing to do with the question of betting "experiences".



> I think that you've heard all my
> arguments.
>
>> Why not choose D, that is "I will see 0 on the wall OR I will see 1
>> on the wall."
>
> Okay, now you have switched back to the prior (prediction)
> level.

I have not switch back. I always ask you the question before the
duplication. And then, I ask for confirmation of the bet after the
duplication. It is really like, in the MWI, to ask someone what he
predict when he send trillions of electrons in a state like up+down in
a up/down measuring Stern-Gerlach apparatus. Apparently you answer is
"I will see only up electron + I will see one down electron and all
others up + etc. (all possibilities)."

>
> Here is the reason not to say that. As the person who is about
> to be duplicated knows all the facts, he is aware (from a 3rd
> person point of view) that scientifically there will be *two*
> processes both of which are very, very similar.


Right.


> It will be
> false that one of them will be more "him" than the other.

Right.


> Therefore he must identify equally with them. Therefore,
> it is wrong to imply that he "I" will be one of them but not
> the other of them.

This is a matter of choice and personal opinion. It does not address
the question I asked. The question is not who you will be, but what
will be your immediate feeling. Given that we assume comp it is easy to
predict that you will either see 0 or see 1. You will not see a zero
blurred with a one. You can in advance bet you will see only a zero
(resp. one), and just intellectually know some "other you" will see a
one (resp. zero).


>
> But if you answer "I will see 0 on the wall OR I will see 1 on the
> wall"
> then it makes it sound as though one of those cases will obtain but
> not the other.

Actually I was using the non-exclusive OR! But I do think that the
first person experiences of seeing 1 and 0 *are* indeed alternative
experience. After one duplication, those experience will be exclusive
of each other. You are not able to know the experience of the
doppelganger in the same sense that you will be able to see directly
the output on the wall.



> (This is usually how we talk when Bruno admits, for
> example, that tonight he either will watch TV *or* he will not watch
> TV. But the case of duplicates is not like that. In the case of
> duplicates, it is a scientific fact that Bruno will watch TV (in one
> room) and will not watch TV (in the other room). In short, it will
> be true that Bruno will watch TV and will not watch TV---simply because
> there will be two instances of Bruno.)

Yes but Bruno knows in advance that as far as we talk about its future
experience, he will be directly aware only of watching TV, or of not
watching TV (and knowing just intellectually that the other Bruno watch
TV).
I recall: the bet concerns the first person experiences.


>
>> I recall you that "p or q" is true if p is true or q is true.
>> So with D all the Lee will win. D consists into admitting that
>> you are ignorant about your immediate apprehension after the
>> duplication. It has nothing to do with the fact that you are
>> the two Lee.
>>
>> OK?
>
> Nope. :-) With D, I am pretending that it is like you watching
> television---either 0 or 1. But with duplicates it is not like
> that: instead it is like 0 AND 1.

You shift from 1-person to 3-person, when the question is a bet, before
the duplication, of the immediate first person experience.

But you know, before the duplication that all the Lee will have
alternate experiences. So I really don't understand you bet.
Mathematically your bets make you win 0 dollars. By betting on your
ignorance (1 OR 0), you will always be confirmed and you win 5 dollars
at each duplication. You and all the Lee. It seems to me you are hard
with your (first person) selves.


Bruno

http://iridia.ulb.ac.be/~marchal/
Received on Mon Jul 11 2005 - 07:06:14 PDT

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