Some comments

From: Marchal <marchal.domain.name.hidden>
Date: Mon May 10 03:35:37 1999

Hi Nick, Gilles, Jacques and all Everythingers,


Nick Bostrom wrote:
>The Self-Sampling Assumption (SSA), the idea that you should reason
>as if you were a random sample form the set of all observers,
>underlies many of the discussions we have had on this list. About
>half a year ago I discovered some paradoxical consequences of this
>assumption. It seems to imply that weird backwards causation and
>psychokinesis(!) is feasible in our world. In this small paper I
>describe these possible counterexamples and discuss whether they
>really are as paradoxical as they appear at first blush:

I think your paper is essentially correct, but the notion of "set of all
observers" is far from clear to me. In my work (cf signature below)
I use a much weaker *necessarily conditionnal (or relative)* "Self-
Sampling Assumption".


Gilles Henry wrote:
>But a conscious being cannot exist without being
>perturbated by its environment (in fact we are conscious BECAUSE we are
>constantly interacting with our environment).

This seems to me to be in contradiction with any standart
computationnalist
account of the dream phenomenon.
I just mean you cannot believe what you say here without being
inconsistent
with computationnalism.


Jacques M Mallah quoted a letter by Don N Page (adressed to Jacques M
Mallah):
> Thanks for your message. Jerry Finkelstein had asked me how the
>evidence of one's living to 2100 would be any diferent from the
>evidence of
>getting any other low-measure result, which would occur in MWI. (I
>suppose the
>only difference I see is that one would not be alive to be aware of the
>contrary evidence in other worlds.) But this got me to realize that
>although
>the maverick worlds in which one would live to 2100 certainly exist in the
>MWI,
>they would have so low a measure that one experiencing it would be
>experiencing
>a very low typicality observation, which if one counts the typicality as
>the
>likelihood, as I argue one should do in my Sensible Quantum Mechanics
>papers,
>would be evidence agains the MWI just as strong as against the
>single-history
>version.
> So I agree with your criticism.

So, Jacques, you succeed in convincing Don Page against Quantum
Immortality !
I would not be proud of that!

It seems that you (and Don Page now) reason like that :

Maverick worlds in which I am alive in 2100 are rare, so the probability
I feel alive in 2100 is low.
But, at least with computationnalism (or "comp" if you prefer: I mean the
hypothesis that I can survive with a digital *body*), I can only compute
the probability from a distribution defined on the worlds in which I
survive.
There is no sense in counting worlds in which I do not survive.
Typicality or likelihood are relative to the observer.

Of course the fact I feel alive in 2100 would not be necessarily a
confirmation of the MWI of Quantum Mechanics, it could be *just* a
confirmation of the MWI of computationalism.

You don't believe in comp-immortality, do you ?

Tell me if you agree at least with the weaker proposition:

     COMP + HE ====> immortality

where HE is the (extravagant) hypothesis saying that a real concrete
universal dovetailer (generating and executing all programs) exists
in our "universe".
If you agree, my only task will be to show you how to eliminate HE.

Bruno














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Received on Mon May 10 1999 - 03:35:37 PDT

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