On 30-Jun-01, Marchal wrote:
> Finney wrote:
>> Marchal writes:
>>> Here is question 6. Perhaps the first not so obvious one.
>>> Do you agree that, if I ask you at Brussels, before the
>>> Washington-Moscow duplication experiment: "Where will you *feel*
>>> to be after the experiment will be completed?" that although
>>> you can answer "you will see me at Washington and at Moscow",
>>> your first person diary will either contain "I am at Moscow" or
>>> I am at Washington" so that you cannot predict with certainty
>>> where you will feel to be?"
>> I don't think this is a meaningful question, because it is not
>> "operational", that is, it is just a matter of opinion and does not
>> require anyone to take any action.
>> Suppose you were French and, faced with this experiment, you were
>> asked, would you study English or Russian prior to engaging in this
>> experiment? That is an operational question. If you think you will be
>> in Moscow, you would study Russian; if Washington, English. If
>> neither, then I suppose you would not study either one. For me, I
>> would study both.
>> However I would refuse to answer a question like "where will you feel
>> to be", not because I can't predict the answer with certainty, but
>> because I don't think "you" is a well defined concept in the context
>> of this experiment. It's not that the answer to the question is
>> unpredictable, it's that the question is meaningless.
> If you answer "yes" to the question 5 (do you survive duplication) it
> to me that the question is meaningful. After all if "I" survive (in
> grand-mother sense), it is natural to ask myself where I will feel to
> I don't see the difference whith the experience where I ask you to
> look at a photon in the superposition state a + b, and asking you to
> go in W if you find the photon in state a, and to go at Moscow if you
> find the photon in state b. Here too there is a sense to ask you where
> you will feel to be, and with MWI both alternatives are realised.
I think I agree with Hal. The question seems particularly tricky in
English because "you" is ambigously singular and plural. If you avoid
this ambiguity the question becomes, "Where will you two feel to be
after the experiment?" But the question isn't being asked of "you two"
but only of "you".
The question is also unanswerable in the second form refering to the
superposed photon states. But not because of the ambiguity of "you"
but simply because there is no way to know the answer. It' like
asking, "I'm going to flip this coin. Will you see it come down heads
or will you see it tails?"