On 28 Sep 2015, at 18:21, John Clark wrote:
On Sun, Sep 27, 2015 Bruno Marchal <marc...@ulb.ac.be> wrote:
>>> If you prove the existence of something in something
else, you have that something,
>> Euclid proved 2500 years ago that there are infinitely
many primes, so if what you say above is true you must have the
423rd prime greater than 10^100^100.
> Now you equate existence with constructive existence,
What the hell? You're the one that is equating those two things
not me! I don't want you to answer the question "does the 423rd
prime number greater than 10^100^100 exist?", I want you to tell me
the answer to a completely different question, "what is the 423rd
prime number greater than 10^100^100?".
So you are asking me a constructive existence of such a number, and
even a consturctive in a not well defined physical sense.
But Computationalism, is at the start classical, not intutionist nor
constructive. Some brnch of computer science are necessarily non
constructive, and eventually we rediscover this in the epistemology of
the machine.
The question was: does computation (in the original standard sense of
Turing's or Church's definition of computability, using the
intensional Church thesis (which says that not only all universal
machines compute the same class of functions, but all universal
machines can emulate all universal machine, that is, all universal
machine can imitate exactly all digital processes starting from finite
conditions (relatively or not to some oracle).
And the answer I gave was: I can prove (in RA, or let a theorem prover
of RA prove ...) the existence of the terminating computations, and
of all the segments of the infinite computations.
This entails in particular that the computations are all emulated, or
realized, in or by the usual "standard model" or arithmetic (N, 0, +,
x) taught in high school.
So the relative computations, the sigma_1 arithmetical relations,
exist in the usual 3p sense of asserting, for example, that the prime
numbers, including those greater 100^(100^100).
Such existence should not be confuse with a stronger feasible
existence (in which case we ask for an algorithm generating the
existing object + the constraint to present it in some reasonable
delay).
Nor, should that existence be confused with some notion of physical
existence, especially in a context where we want explain the physical
by something non-physical.
And to figure out what that number is and answer my question you are
going to have perform a calculation. And to do that you are going to
have to use matter that obeys the laws of physics. And there may not
be enough matter in existence to do it. And if there isn't then the
question "what is the 423rd prime number greater than 10^100^100?"
is unanswerable.
I use computation is the mathematical sense of Alonzo Church, Emil
Post, Stephen Kleene, Alan Turing, Matiyazevic, etc.
>>> indeed a universal machine cannot distinguihs a
physical computation from a non physical one,
>> I know, and that lack of ability is yet another example
of something a non-physical machine can't do that a physical
machine can. A physical machine, such as myself, has no
difficulty whatsoever in making that distinction.
> Then you have magical abilities not shared by any Turing
machine, physical or non physical.
Bullshit.
> Please don't confuse the computation with anything we use to
represent and communicate about that computation.
Gibberish.
>> so just use immaterial computation to find the 423rd
prime greater than 10^100^100 and tell me what it is and you have
won this argument. How hard can that be?
> Just define what *you* mean by "physical computation"
It means computation using physics.
Computation in which sense? If it is the Turing sense, then that exist
in arithmetic.
If by using physics you mean that there exist something which select
one computation to make it more real, then that is using a god-of-the-
gap to prevent the searching of a solution of the mind-body problem in
the computationalist frame.
Bruno, couldn't you have figured that out by yourself? Did you
really need my help?
I figure that out since long, I mean ... that you restrict the
standard sense of computation to their possible realization in the
physical reality.
The problem is that you give the impression that you believe that
computation does not exist in, or be emulated by, arithmetic. That has
nothing to do with the question of the feasibility or of the physical
realisability, especially in the context of the computational or
digital thesis in philosophy of mind-matter.
Then I exploit the fact that sigma_1 complete provability is
equivalent with universal computability.
And I interview machines having enough introspection power (in the
standard Gödel sense) to know (in a technical sense) that they are
sigma_1 complete (they prove p -> []p for all p sigma_1).
You have agreed that consciousness is not something localized
somewhere, and indeed, there is an infinity of computations (that is
running universal machines) accessing your state in arithmetic, and we
have to justify the appearance of local histories/computations from
that.
Saying that there is a physical universe doing that is no better than
saying God made it.
Note that saying that there is a physical universe doing that *might*
be the correct theory if it is provided with an explanation of how it
makes that selection possible. But without making the mind using
special actual infinities, that explanation has to be deducible by the
self-introspecting machine betting on computationalism, if
computationalism is correct.
Indeed, using the modal tools of the logic of self-reference, we
recover diverse nuance of the physicalness with the logics []p & p,
[]p & <>t, []p & <>t & p, with p restricted to the sigma_1 sentences.
Those nuances varies on quantum logics and intuitionistic quantum
logics. They provide arithmetical quantizations in a sense coming from
the modal logical analysis of quantum logic (Golblatt, Rawling and
Selesnick, Dalla Chiara, etc.). (Not to be confuse with van Fraessen
Modal interpretation of QM).
Bruno
John K Clark
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
