On 09 Dec 2011, at 19:47, Joseph Knight wrote:
On Fri, Dec 9, 2011 at 3:55 AM, Bruno Marchal <marc...@ulb.ac.be>
On 09 Dec 2011, at 06:30, Joseph Knight wrote:
I was cruising the web when I stumbled upon a couple of PDFs by
Jean-Paul Delahaye criticizing your work. (PDF 1, PDF 2). I don't
speak French, but google translate was able to help me up to a
point. The main point of PDF 1, in relation to the UDA, seems to be
that there is not necessarily a notion of probability defined for
truly indeterministic events. (Is this accurate? Are there any
results in this area? I couldn't find much.)
Jean-Paul Delahaye was the director of my thesis, and in 2004, when
I asked him why I did not get the gift (money, publication of the
thesis, and promotion of it) of the price I got in Paris for my
thesis, he told me that he has refuted it (!). I had to wait for
more than six year to see that "refutation" which appears to be only
a pack of crap.
So you never got the money, publication, or promotion?
I get only defamation.
Most objection are either rhetorical tricks, or contains elementary
logical errors. I will, or not, answer to those fake objections. I
have no clue why Delahaye acts like that. I think that if he had a
real objection he would have told me this in private first, and not
under my back. He showed a lacking of elementary scientific
deontology. He might have some pressure from Paris, who witnessed
some pressure from Brussels to hide a belgo-french academical
scandal, but of course he denies this.
So Delahaye is that unique "scientist", that i have mentionned in
some post, who pretend to refute my thesis. My director thesis!
The translation of PDF 2, with regards to the Movie Graph argument,
was much harder for me to understand. Could you help me out with
what Delayahe is saying here, and what your response is? I am just
curious about these things :) I noticed some discussion of removing
stones from heaps, and comparing that to the removal of subparts of
the filmed graph, which to me seemed to be an illegitimate analogy,
but I would like to hear your take...
The heap argument was already done when I was working on the thesis,
and I answered it by the stroboscopic argument, which he did
understand without problem at that time. Such an argument is also
answered by Chalmers fading qualia paper, and would introduce zombie
in the mechanist picture. We can go through all of this if you are
interested, but it would be simpler to study the MGA argument first,
for example here:
There are many other errors in Delahaye's PDF, like saying that
there is no uniform measure on N (but there are just non sigma-
additive measures), and also that remark is without purpose because
the measure bears on infinite histories, like the iterated self-
duplication experience, which is part of the UD's work, already
All along its critics, he confuses truth and validity, practical and
in principle, deduction and speculation, science and continental
philosophy. He also adds assumptions, and talk like if I was
defending the truth of comp, which I never did (that mistake is not
unfrequent, and is made by people who does not take the time to read
the argument, usually).
I proposed him, in 2004, to make a public talk at Lille, so that he
can make his objection publicly, but he did not answer. I have to
insist to get those PDF. I did not expect him to make them public
before I answered them, though, and the tone used does not invite me
to answer them with serenity. He has not convinced me, nor anyone
else, that he takes himself his argument seriously.
The only remark which can perhaps be taken seriously about MGA is
the same as the one by Jacques Mallah on this list: the idea that a
physically inactive material piece of machine could have a physical
activity relevant for a particular computation, that is the idea
that comp does not entail what I call "the 323 principle". But as
Stathis Papaioannou said, this does introduce a magic (non Turing
emulable) role for matter in the computation, and that's against the
comp hypothesis. No one seems to take the idea that comp does not
entail 323 seriously in this list, but I am willing to clarify this.
Could you elaborate on the 323 principle?
With pleasure. Asap.
It sounds like a qualm that I also have had, to an extent, with the
MGA and also with Tim Maudlin's argument against supervenience --
the notion of "inertness" or "physical inactivity" seems to be
I will explain why you can deduce something precise despite the
vagueness of that notion. In fact that vagueness is more a problem fro
a materialist than an immaterialist in fine.
Indeed, it is not yet entirely clear for me if comp implies 323
*logically*, due to the ambiguity of the "qua computatio". In the
worst case, I can put 323 in the defining hypothesis of comp, but
most of my student, and the reaction on this in the everything list
suggests it is not necessary. It just shows how far some people are
taken to avoid the conclusion by making matter and mind quite magical.
I think it is better to study the UDA1-7, before MGA, and if you
want I can answer publicly the remarks by Delahaye, both on UDA and
I feel quite confident with both the UDA and the MGA (It took me a
I read sane04, and quite a few old Everything discussions, including
the link you gave for the MGA as well as the other posts for MGA 2
I might send him a mail so that he can participate. Note that the
two PDF does not address the mathematical and main part of the
So ask any question, and if Delahaye's texts suggest some one to
you, that is all good for our discussion here.
My main question here would be: when Delahaye says you can't
(necessarily) have probabilities for indeterministic events, is that
Simplifying things a little bit I do agree with that statement. There
are many ways to handle indeterminacies and uncertainty. Probability
measure are just a particular case. But UDA does not rely at all on
probability. All what matters to understand that physics become a
branch of arithmetic/computer science is that whatever means you can
use to quantify the first person indeterminacy, those quantification
will not change when you introduce the delays of reconstitution, the
shift real/virtual, etc.
Formally, the math excludes already probability in favor of
credibility measure. But for the simplicity of the explanation, I use
often probability for some precise protocol. The p = 1/2 for simple
duplication is reasonable from the numerical identity of reconstituted
observers. We have a symmetry which cannot be hoped for any coins!
How would it affect the first few steps of the UDA if there were no
defined probability for arriving in, say, Washington vs Moscow?
Well, in that case, there are probability measure. In the infinite
self-duplication, you can even use the usual gaussian. But even if
there were no such distribution, the result remains unchanged: physics
becomes a calculus of first person uncertainty with or without
probability. As I said, only the invariance of that uncertainty
calculus matter for the proof of the reversal.
Tell me if this answer your question.
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