Re: Craziness of a quantum suicidal

From: Marchal <>
Date: Thu Jun 24 11:08:53 1999

Jacques M Mallah wrote:

> I'm not going to elaborate on this now because I have a ton of
>work. Instead of doing a rush job, I will lay out the case against QS in
>a form suitable for a FAQ, which this list sorely needs, when I get the

Nice !

>No doubt someone will write up a case in favor of it and people can
>be referred to the FAQ. This will have to serve when I unsubscribe.
> Suffice it to say, though, that whether the number of branches is
>finite or infinite makes little difference. The point is you lose measure
>with a QS.
>Some people in the multiverse have more measure than others,
>and measure is proportional to effective probability. If you deny this I
>don't see how you can even explain why people descended from apes have
>higher effective probability than those that form spontaneously.

I do agree with the relation between measure and effective probability.
The solution is linked to Wei Dai's *little program*. Although that is
not enough. But OK, let us not try to resolve this issue now.

>> [BM] The problem is that Jacques M Mallah is computationnalist. I am afraid
>> that this entails he has no other choice than to choose the relative SSA.
>> Only by choosing a strong physicalist ontological principle AND by
>> choosing a strong (and rather mysterious) link between consciousness and
>> physical activity, will it be possible for him to get a "limited MW" in
>> which branching is absolute. Such a link between consciousness and
>> physical activity has been showed incompatible with mechanism (by myself
>> in 1988, and independently by Tim Maudlin in 1989, precise reference in
> [JM] Yeah right. I wanted to see this crackpot proof only because
>(unlike QS) it does directly touch on my interests, but unfortunately it
>was unreadable. So what's the idea of the "proof"? In English.

1) I like very much your sense of humor, Jacques. Do you really believe
I will be clearer in English ? ... and without drawings, and without
hands waving ?

2) Is is not premature ? I'm still amazed you don't see the point in
the PE-omega thought experiment (the Universal Dovetailer (DU) argument).
After all, the main goal of the *crackpot proof* is the elimination of
the extravagant hypothesis HE, i.e. the need for a CONCRETE execution of a
universal dovetailer (Schmidhuber's great programmer, Wei Dai's
counting algorithm, etc.).

2) Is it necessary ? This very discussion list, as we can realize by
looking at the beginning in the archive, is founded on the idea
(see also Tegmark and Schmidhuber, and (of course) Everett !) that
allowing more [every] things to exist makes possible the isolation of
more [the most] simpler [simplest] explanation possible. This, I think,
means that almost every one in the list accept some kind of
conceptually strong form of Occam Razor (as explicitely,
exemplified by James Higgo). With such an idea, there is no need for
eliminating HE. Any arithmetical (abstract) DU is enough.

3) Is it possible ? When I explain the UD argument (the PE-omega
thought experiment in the list) to people, they usually understand it
And because most of them dislike the conclusion (the ontological
reduction of physics to computer science or number theory,
the disappearence of the universe, the many-worlds phenomenology)
they drop out computationnalism, and go back to their activities.
... or they begin to believe that our universe (beside being unique)
is very little so that HE is false, ... but here enter the crackpot proof.

Unlike the UD argument, when I explain the movie graph argument
(the *crackpot proof* in your so poetical manner to name things),
most people remain silent, looking at me as if I am crazy, or
begin to try to argue upon every things !
I met Tim Maudlin in the early 90thies and ask him about the reaction
to his (equivalent) paper. He told me "none".
I am not to much astonished you find the movie graph argument
(my *crackpot proof*) unreadable.
If I try to explain it, it could be a very long thread ...

4) ... and you tell us you will unsubscribe (snif!). May be you
deserve that I try, at least, to give you the idea, before you go, of
"the proof",
in a nutshell, in "English".

The argument "prove" the incompatibility between computationnalism (comp)
and the physical supervenience thesis (sup-phys) i.e. the
idea that consciousness is linked (causaly, epiphenomenaly,
whatever...) with the physical activity of the brain.

The problem here is that the "physics" cannot distinguish a
counterfactually correct firing of a neuron (for exemple) and an
accidentally correct firing of a neuron.

For exemple, think that
the neuron is broken and that, by pure chance, a cosmic ray supplies
it in real time.
 Then, if consciousness supervenes on the physical activity
of a digital computer (emulating a brain), it will be not difficult
to show that consciousness will supervene
on a physically equivalent device, at some level below our substitution
where the device is build in such a way -by filming the computer- that
all "computationnal activity" will be purely
accidentally correct (like in a cartoon where the dropping of a stone in
a window is NOT the cause of the breakdown of the window).

That mean that consciousness could supervene on something equivalent to a
filmed brain, in which there is no form of "physical" computation at all.
This is basically the idea of the reductio ad absurdum.

5) ... enough for today. I'm tired and my english looks more
and more like french.
I would still like to mention that Hal Finney (if I remember correctly)
has pointed toward a similar form of argument in the discussion.
I don't remember where. I will look for it in the archive.

A+ Bruno

Received on Thu Jun 24 1999 - 11:08:53 PDT

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