Cognitive Theoretic Model of the Universe

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rexal...@gmail.com

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May 30, 2009, 5:08:44 PM5/30/09
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Has anyone on this list ever heard of this? A theory of reality
formulated by Christopher Michael Langan?

http://www.ctmu.org/Articles/IntroCTMU.htm

It sounds a little sketchy at first, though not entirely different
than some of what Bruno Marchal says.

Obviously the main reason to pay much attention to it is that Langan
has an IQ of between 190 and 210. Which kept me going past the first
paragraph, which is when I would otherwise have stopped.

But, after further reading it sounds somewhat more plausible. I'd be
very interested in hearing Bruno's opinion.



russell standish

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May 30, 2009, 7:16:19 PM5/30/09
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I looked into him about a month or so ago, after he'd posted an
unflattering remark about my work. He might have an IQ of 200, but to
put it bluntly, what he writes is "drivel". It may well have a kernel
of truth, and there may well even be original thought in there, but it
is so voluminous and so badly organised it is impossible to tell.

Basically, my advice to him would be to get a PhD. It doesn't teach
you creativity, but does teach you how to organise and express your
ideas so that others can possibly understand it. But I suspect Chris
Langan is too proud to do this. At least Bruno has done his PhD, and
his work is so much the better off for him having gone through that
process, painful though it was.

Cheers
--

----------------------------------------------------------------------------
Prof Russell Standish Phone 0425 253119 (mobile)
Mathematics
UNSW SYDNEY 2052 hpc...@hpcoders.com.au
Australia http://www.hpcoders.com.au
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Kim Jones

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May 30, 2009, 8:03:41 PM5/30/09
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Why would someone's IQ rating be a recommendation of anything about
them?

People like Langan long ago fell into the "Intelligence Trap". They
have an exaggerated need to be "right" about everything all the time.
They are usually unable to think about anything from a perspective
other than the one they long ago decided was the "right" perspective.

They don't know how to listen to others. They are usually unable to
restructure the available information in such a way that they can draw
new perspectives from it. Please do not extoll the virtues of anything
as anachronistic and mythical as somebody's supposed "high IQ". I
could put a thinking test in front of him that would defeat him
totally, yet be easily done by a 7 year old.

Kim Jones

russell standish

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May 30, 2009, 9:01:22 PM5/30/09
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On Sun, May 31, 2009 at 10:03:41AM +1000, Kim Jones wrote:
>
> Why would someone's IQ rating be a recommendation of anything about
> them?
>
> People like Langan long ago fell into the "Intelligence Trap". They
> have an exaggerated need to be "right" about everything all the time.
> They are usually unable to think about anything from a perspective
> other than the one they long ago decided was the "right" perspective.
>
> They don't know how to listen to others. They are usually unable to
> restructure the available information in such a way that they can draw
> new perspectives from it. Please do not extoll the virtues of anything
> as anachronistic and mythical as somebody's supposed "high IQ". I
> could put a thinking test in front of him that would defeat him
> totally, yet be easily done by a 7 year old.
>
> Kim Jones
>

Exactly to all of the above. And it was kind of my point about the use
of doing PhDs. I didn't write the statement below (note the two levels
of quoting), rexallen314 did.

Cheers

>
>
> On 31/05/2009, at 9:16 AM, russell standish wrote:
>
> >> Obviously the main reason to pay much attention to it is that Langan
> >> has an IQ of between 190 and 210. Which kept me going past the first
> >> paragraph, which is when I would otherwise have stopped.
>
>
>

Rex Allen

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May 30, 2009, 9:24:46 PM5/30/09
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> Why would someone's IQ rating be a recommendation of anything about
> them?

Well, someone who's 8 feet tall is not necessarily going to be good at
basketball, or even have the other abilities needed to excel at
basketball, BUT I think it seems reasonable to think that it might be
interesting to watch them play. More interesting than watching
someone who's 6 feet tall...if for no other reason than sheer novelty.

And so, I pressed forward past the first paragraph.

Langan does seem to have some peculiar personality quirks, but he's
had a peculiar life, so it's not clear what would be the most likely
explanation for that.

But, all of that is neither here nor there. What I'm curious about is
whether there's anything to what he says.

I agree with Russell's point, many of the things I found online that
Langan has written do seem to be obscure to the point of drivel.

However, the previous link I posted was reasonably well written, and
he has another one here:

http://www.iscid.org/papers/Langan_CTMU_092902.pdf

If you ignore the stuff about the possibility of "intelligent design"
in the opening section, he makes some interesting points in the
following sections.

But, if you say it's all crap, I have no problem with that. I'm not
here to advocate for Langan. Just to see what people's opinions are.
It's all good. Peace brothers!

Bruno Marchal

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May 31, 2009, 1:02:34 PM5/31/09
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It is a physicalism in disguise. There is also a confusion between a
mathematical object as a tool to represent other object, and the other
object.
And using set theory in that setting is a curious choice, given that
set theory is known to flatten the concepts. It is the reason what
mathematician prefer category theory, or specific theories ... I mean
sets? Which sets? It is very unclear how the different notions are
related. I can appreciate its apparent open mind on religion, but I
don't see any effort to solve problems, nor any clarification of
problems. Langan seems not to be afraid of being appreciated by those
who want to be mystified instead of understanding.
But then if you have a link on a real precise theory or results, you
can let us know, but my opinion is that it is not really honest, or if
it is, then it is presented in a very awkward. To give set a
fundamental status is really like saying you should do everything in
FORTRAN. Unless you have a good original reason to use sets, but then
you should give it.
Rereading some parts I am not sure at all he even try to say
something, ... pervert the usual meaning of the terms. He makes
complex simple ideas and hides somehow its naive view of Plato, making
me a bit nervous even on points where I could imagine some sense
there ...
...
Hmm.... Pompous and Boring, if you ask my opinion.

Bruno


http://iridia.ulb.ac.be/~marchal/

Rex Allen

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Jun 1, 2009, 11:48:13 AM6/1/09
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Good information, thanks!

John Mikes

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Jun 1, 2009, 3:20:47 PM6/1/09
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Russell, I second (if it is of any worth).
 
I 'tried' to read the diatribes on the html page and my perseverence ws not sufficient to stay in he lines. Some concepts seem to be mixed (I did not say "up") e.g. to identify 'reality' one should get a hold of it and I found 'physical' sketchy (maybe I blurred-up where it was more sorrowly identified). . .
It was funny to read about ONE universe in all, spacetime etc. as universal foundations, and so on, I think this list is past such level.
About the Ph.D.: I agree, it is a harsh schooling to compose/order ideas an regulate one's thinking (if the tutor is any good). My 2nd one was a lot easier than the 1st one. I don't care too much for titles, but in terms as a mental training I appreciate your position.
 
I don't care too much for high IQs either (was measured once for a job interview and they disclosed upon my threat only that it was >200) - but I assigned it to the metric system I grew into: saved lots of time in the math problems by converting the US units into metric, play with the decimal point and reformed the US units. Which is not much of an intelligence. Other topics in those tests are cultural background related, plus a snobbish preference for certain domains in the cognitive inventory by the organizers of the particular test. People with other background may fail.
 
John M

Jason Resch

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Jun 1, 2009, 4:52:11 PM6/1/09
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I think these interviews provide a nice summary of his views:

http://www.youtube.com/watch?v=-ak5Lr3qkW0
http://www.youtube.com/watch?v=6mfbUhs2PVY

I remember seeing an interview with him on TV about a decade ago and
being very interested in his claim to be able to mathematically prove
the existence of god, souls, and life after death, but I don't know if
he's ever revealed those proofs. It seems with Bruno's testable comp
hypothesis we can do the same, depending on your definitions of god,
souls, and life after death.

Jason

Colin Hales

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Jun 1, 2009, 8:57:54 PM6/1/09
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hmmmmmmmm. Some thorts.

:-) I love the 'duncical equilibrium' that is our leadership....sounds like the 'coalition of the willing'.

He's seems to be a damaged guy, although aren't we all? The infuriating blindness of the masses (alias the wisdom of the crowd!) gnaws on his butt.

Yes....we need a cognitive Einstein, but there's a possibility he would end up the bouncer at the 'bar of the new authoritarian mess', despite the plan of reality he claims to have. Maybe we are entering an era where such an approach will save us.... but I'd prefer a 'new enlightenment' to a pile of 'anti-diseugenics' any day. Doesn't fit my idea of 'kindness'.

....his use of the word god detaches it from faith...That has to be a good move.

There's too much focus on the fact of genius and not enough being one.

His endomorphic image of the mind of god translates to what we recognise self similarity at all scales... and the tautologousness of  any recursive structure.... all of which the folks here will relate to.

He reminded me of the snorefest incremental science factory I inhabit here.

....recent explanatory paper attached.

Charlton, B. G. 'Why are modern scientists so dull? How science selects for perseverance and sociability at the expense of intelligence and creativity', Medical Hypotheses vol. 72, no. 3, 2009. 237-243.

It calls for a place to nurture these guys ... these 'strange and luminous fools' as charlton puts it. I think I might have 1 foot in this camp ... the idea of it scares me ... but when I introspect....there I am. Kept from the dungheap by the relentless seeking of truth.

cheers
col
2009.pdf

Stathis Papaioannou

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Jun 2, 2009, 7:45:20 AM6/2/09
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2009/6/2 Jason Resch <jason...@gmail.com>:

>
> I think these interviews provide a nice summary of his views:
>
> http://www.youtube.com/watch?v=-ak5Lr3qkW0
> http://www.youtube.com/watch?v=6mfbUhs2PVY

I can't say I've ever seen a more extreme example of a narcissist.


--
Stathis Papaioannou

ronaldheld

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Jun 2, 2009, 10:45:22 AM6/2/09
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Bruno:
Since I program in Fortran, I am uncertain how to interpret things.
Ronald
On May 31, 1:02 pm, Bruno Marchal <marc...@ulb.ac.be> wrote:

russell standish

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Jun 2, 2009, 6:38:28 PM6/2/09
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On Tue, Jun 02, 2009 at 07:45:22AM -0700, ronaldheld wrote:
>
> Bruno:
> Since I program in Fortran, I am uncertain how to interpret things.
> Ronald

Maybe if he said Fortran IV or Fortran 66, it might have made the
point clearer. I know guys who still program in Fortran 66. The rest
of us have moved on ... Fortran 95 is not a bad language to program in
for instance - and 2003 has some interesting features, although I don't
know of any freely available compilers.

Personally, I went C++ in the early 90s because g++ was available and
the equivalent for Fortran 90 was not (gfortran or g95 arrived by
about 2000 IIRC).

ronaldheld

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Jun 4, 2009, 7:17:19 AM6/4/09
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Russell:
Maybe you might be interested in gfortran(http://gcc.gnu.org/wiki/
GFortran)?
Ronald

On Jun 2, 6:38 pm, russell standish <li...@hpcoders.com.au> wrote:
> On Tue, Jun 02, 2009 at 07:45:22AM -0700, ronaldheld wrote:
>
> > Bruno:
> >    Since I program in Fortran, I am uncertain how to interpret things.
> >                                       Ronald
>
> Maybe if he said Fortran IV or Fortran 66, it might have made the
> point clearer. I know guys who still program in Fortran 66. The rest
> of us have moved on ... Fortran 95 is not a bad language to program in
> for instance - and 2003 has some interesting features, although I don't
> know of any freely available compilers.
>
> Personally, I went C++ in the early 90s because g++ was available and
> the equivalent for Fortran 90 was not (gfortran  or g95 arrived by
> about 2000 IIRC).
>
> --
>
> ---------------------------------------------------------------------------­-
> Prof Russell Standish                  Phone 0425 253119 (mobile)
> Mathematics                              
> UNSW SYDNEY 2052                         hpco...@hpcoders.com.au
> Australia                                http://www.hpcoders.com.au
> ---------------------------------------------------------------------------­-

Bruno Marchal

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Jun 4, 2009, 10:49:43 AM6/4/09
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Hi Ronald,


On 02 Jun 2009, at 16:45, ronaldheld wrote:

>
> Bruno:
> Since I program in Fortran, I am uncertain how to interpret things.

I was alluding to old, and less old, disputes again programmers, about
which programming language to prefer.
It is a version of Church Thesis that all algorithm can be written in
FORTRAN. But this does not mean that it is relevant to define an
algorithm by a fortran program. I thought this was obvious, and I was
using that "known" confusion to point on a similar confusion in Set
Theory, like Langan can be said to perform.

In Set Theorist, we still find often the error consisting in defining
a mathematical object by a set. I have done that error in my youth.
What you can do, indeed, is to *represent* (almost all) mathematical
objects by sets. Langan seems to make that mistake.

The point is just that we have to distinguish a mathematical object
and the representation of that object in some mathematical theory.

I will have the opportunity to give a precise example in the 7th
thread later.

In usual mathematical practice, this mistake is really not important,
yet, in logic it is more important to take into account that
distinction, and then in cognitive science it is *very* important.
Crucial, I would say. The error consisting in identifying
consciousness and brain state belongs to that family, for example. To
confuse a person and its body belongs to that family of error too.

All such error are of the form of the confusion between the Moon and
the finger which point to the moon, or the confusion between a map and
the territory.

I have nothing against the use of FORTRAN. On the contrary I have a
big respect for that old venerable high level programming language :)

Bruno

http://iridia.ulb.ac.be/~marchal/

Brian Tenneson

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Jun 4, 2009, 11:09:23 AM6/4/09
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From my understanding of logic, there is made the distinction between objects and descriptions of objects.
For example, the relation "is less than" is considered different from the relation symbol <
So what you said makes sense.

Brent Meeker

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Jun 4, 2009, 1:28:56 PM6/4/09
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Bruno Marchal wrote:
> Hi Ronald,
>
>
> On 02 Jun 2009, at 16:45, ronaldheld wrote:
>
>
>> Bruno:
>> Since I program in Fortran, I am uncertain how to interpret things.
>>
>
> I was alluding to old, and less old, disputes again programmers, about
> which programming language to prefer.
> It is a version of Church Thesis that all algorithm can be written in
> FORTRAN. But this does not mean that it is relevant to define an
> algorithm by a fortran program. I thought this was obvious, and I was
> using that "known" confusion to point on a similar confusion in Set
> Theory, like Langan can be said to perform.
>
> In Set Theorist, we still find often the error consisting in defining
> a mathematical object by a set. I have done that error in my youth.
> What you can do, indeed, is to *represent* (almost all) mathematical
> objects by sets. Langan seems to make that mistake.
>
> The point is just that we have to distinguish a mathematical object
> and the representation of that object in some mathematical theory.
>

Just so I'm sure I understand you; do you mean that, for example, the
natural numbers exist in a way that is independent of Peano's axioms and
the theorems that can be proven from them. In other words you could add
to Peano's axioms something like Goldbach's conjecture and you would
still have the same mathematical object?

Brent

Bruno Marchal

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Jun 4, 2009, 2:31:30 PM6/4/09
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On 04 Jun 2009, at 19:28, Brent Meeker wrote:


Bruno Marchal wrote:
Hi Ronald,


On 02 Jun 2009, at 16:45, ronaldheld wrote:


Bruno:
 Since I program in Fortran, I am uncertain how to interpret things.


I was alluding to old, and less old, disputes again programmers, about  
which programming language to prefer.
It is a version of Church Thesis that all algorithm can be written in  
FORTRAN. But this does not mean that it is relevant to define an  
algorithm by a fortran program. I thought this was obvious, and I was  
using that "known" confusion to point on a similar confusion in Set  
Theory, like Langan can be said to perform.

In Set Theorist, we still find often the error consisting in defining  
a mathematical object by a set. I have done that error in my youth.
What you can do, indeed, is to *represent* (almost all) mathematical  
objects by sets. Langan seems to make that mistake.

The point is just that we have to distinguish a mathematical object  
and the representation of that object in some mathematical theory.


Just so I'm sure I understand you; do you mean that, for example, the
natural numbers exist in a way that is independent of Peano's axioms


Not just the existence of the natural numbers, all the true relations are independent of the Peano Axioms, and of me, ZF, ZFC and you.



and
the theorems that can be proven from them.


A formal theory is just a machine which put a tiny light on those truth.




 In other words you could add
to Peano's axioms something like Goldbach's conjecture and you would
still have the same mathematical object?


The whole point of logic is to consider the "Peano's axioms" as a mathematical object itself, which is studied mathematically in the usual informal (yet rigorous and typically mathematica) way.

PA, and PA+GOLDBACH are different mathematical objects. They are different theories, or different machines.

Now if GOLDBACH is provable by PA, then PA and PA+GOLDBACH shed the same light on the same arithmetical truth. In that case I will identify PA and PA+GOLDBACH, in many contexts, because most of the time I identify a theory with its set of theorems. Like I identify a person with its set of (possible) beliefs.

If GOLDBACH is true, but not provable by PA, then PA and PA+GOLDBACH still talk on the same reality, but PA+GOLDBACH will shed more light on it, by proving more theorems on the numbers and numbers relations than PA. I do no more identify them, and they have different set of theorems.

If GOLDBACH is false. Well GOLBACH is PI_1, that is, its negation is SIGMA_1, that is, it has the shape "it exist a number such that it verify this decidable property". Indeed the negation of Goldbach conjecture is "it exists a number bigger than 2 which is not the sum of two primes". This, if true, is verifiable already by the much weaker RA (Robinson arithmetic). So, if GOLDBACH is false PA + GOLDBACH is inconsistent. That is a mathematical object quite different from PA!

Here, you would have taken the twin primes conjecture, and things would have been different, and more complex.

Note that a theory of set like ZF shed even much more large light on arithmetical truth, (and is still incomplete on arithmetic, by Gödel ...).
Incidentally it can be shown that ZF and ZFC, although they shed different light on the mathematical truth in general, does shed exactly the same light on arithmetical truth. They prove the same arithmetical theorems. On the numbers, the axiom of choice add nothing. This is quite unlike the ladder of infinity axioms.

I would say it is and will be particularly important to distinguish chatting beings like RA, PA, ZF, ZFC, etc... and what those beings are talking about. 

Bruno









Brent Meeker

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Jun 4, 2009, 3:23:29 PM6/4/09
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Bruno Marchal wrote:
> ...

>> Bruno Marchal wrote:
>
> The whole point of logic is to consider the "Peano's axioms" as a
> mathematical object itself, which is studied mathematically in the
> usual informal (yet rigorous and typically mathematica) way.
>
> PA, and PA+GOLDBACH are different mathematical objects. They are
> different theories, or different machines.
>
> Now if GOLDBACH is provable by PA, then PA and PA+GOLDBACH shed the
> same light on the same arithmetical truth. In that case I will
> identify PA and PA+GOLDBACH, in many contexts, because most of the
> time I identify a theory with its set of theorems. Like I identify a
> person with its set of (possible) beliefs.
>
> If GOLDBACH is *true, but not provable* by PA, then PA and PA+GOLDBACH
> still talk on the same reality, but PA+GOLDBACH will shed more light
> on it, by proving more theorems on the numbers and numbers relations
> than PA. I do no more identify them, and they have different set of
> theorems.
>
> If GOLDBACH is false. Well GOLBACH is PI_1, that is, its negation is
> SIGMA_1, that is, it has the shape "it exist a number such that it
> verify this decidable property". Indeed the negation of Goldbach
> conjecture is "it exists a number bigger than 2 which is not the sum
> of two primes". This, if true, is verifiable already by the much
> weaker RA (Robinson arithmetic). So, if GOLDBACH is false PA +
> GOLDBACH is inconsistent. That is a mathematical object quite
> different from PA!

So what then is the status of the natural numbers? Are there many
different objects in Platonia which we loosely refer to as "the natural
numbers" or is there only one such object and the Goldbach conjecture is
either true of false of this object?


>
> Here, you would have taken the twin primes conjecture, and things
> would have been different, and more complex.

Because, even if it is false, it cannot be proven false by exhibiting an
example?

>
> Note that a theory of set like ZF shed even much more large light on
> arithmetical truth, (and is still incomplete on arithmetic, by Gödel ...).
> Incidentally it can be shown that ZF and ZFC, although they shed
> different light on the mathematical truth in general, does shed
> exactly the same light on arithmetical truth. They prove the same
> arithmetical theorems. On the numbers, the axiom of choice add
> nothing. This is quite unlike the ladder of infinity axioms.
>
> I would say it is and will be particularly important to distinguish
> chatting beings like RA, PA, ZF, ZFC, etc... and what those beings are
> talking about.
>
> Bruno

Do you mean PA talks about the natural numbers but PA+theorems is a
different mathematical object than N?

Brent

ronaldheld

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Jun 5, 2009, 8:23:46 AM6/5/09
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Bruno:
I understand a little better. is there a citition for a version of
Church Thesis that all algorithm can be written in
FORTRAN?
Ronald

Quentin Anciaux

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Jun 5, 2009, 8:38:05 AM6/5/09
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Well as FORTRAN is a turing complete language, then you can.

As long as the programming language is universal/turing complete you can.

http://en.wikipedia.org/wiki/Turing_completeness

Regards,
Quentin

2009/6/5 ronaldheld <Ronal...@gmail.com>:
--
All those moments will be lost in time, like tears in rain.

Bruno Marchal

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Jun 5, 2009, 9:18:27 AM6/5/09
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Nobody can answer this question in your place.
But if you believe that the principle of excluded middle can be
applied to closed arithmetical sentences, like 99,999% of the
mathematician, then you have to believe that the Goldbach conjecture
is either true or false.
Even intuitionist will admit that Goldabch conjecture is true or
false, given its Sigma_1 character. This means that, about the (true-
or-false) nature of GOLDBACH is doubtable only for an ultrafinitist.
BTW, Goldbach conjecture asserts that all female (even) numbers can be
written as a sum of two primes, except the number two. (I forget the
word "even" in my enunciation above!).

>
>>
>> Here, you would have taken the twin primes conjecture, and things
>> would have been different, and more complex.
>
> Because, even if it is false, it cannot be proven false by
> exhibiting an
> example?

Yes. And this entails that both PA+TPC and PA + (~TPC) could be
consistent, yet one of those theory has to be unsound, or if you
prefer has to enunciate false arithmetical statements (yet consistent
with PA).
"Sound" is relative to the usual understanding of the natural numbers
which is presupposed in any work in mathematical logic or computer
science, like it is presupposed in any part of any physical theory.
That usual meaning is taught in primary school without any trouble.
In model theory, this notion of soundness can be made more precise,
through the notion of standard model of PA for example, but this
presupposes, in the meta-theory, an understanding of that usual notion
of numbers.
Nobody doubts the consistency and soundness of the theories like RA
and PA. (Even Torgny, who fakes that he doubts them for a
philosophical purpose unrelated to our discussion, like he fakes to be
a faking zombie, etc. This is clear from older post by Torgny).


>
>
>>
>> Note that a theory of set like ZF shed even much more large light on
>> arithmetical truth, (and is still incomplete on arithmetic, by
>> Gödel ...).
>> Incidentally it can be shown that ZF and ZFC, although they shed
>> different light on the mathematical truth in general, does shed
>> exactly the same light on arithmetical truth. They prove the same
>> arithmetical theorems. On the numbers, the axiom of choice add
>> nothing. This is quite unlike the ladder of infinity axioms.
>>
>> I would say it is and will be particularly important to distinguish
>> chatting beings like RA, PA, ZF, ZFC, etc... and what those beings
>> are
>> talking about.
>>
>> Bruno
>
> Do you mean PA talks about the natural numbers but PA+theorems is a
> different mathematical object than N?


I am not sure I understand what you mean. PA is an (immaterial)
machine, or a program if you want. I guess that, by PA+theorems, you
mean the set of theorems of PA. In some context we can identify PA and
PA+theorems, because the context makes things unambiguous. But
strictly speaking those are different mathematical object: PA is
finite (well, as I defined it usually), But PA+theorems is infinite.
Both talk about N, and both are different of N. Indeed PA is a finite
(or infinite in the usual first order presentation) set of axioms and
rules, PA+theorems is an infinite set of formula, and N is an infinite
set of numbers. That is very different. Of course both PA and PA
+theorems (your wording) talk really about the structure (N, +, x),
that is the set of numbers N together with its additive and
multiplicative structure, as studied in school.

It is important to distinguish a theory or a machine (usually a finite
object), with the set of statements proved by that theory or machine
(usually an infinite set).
And it is important to distinguish both of them with the semantical
content of those statements produce by that theory or machine. In
metamathematics (or mathematical logic) that "semantical content" will
itself be represented by a mathematical object (a model) in some other
theory (usually set theory, or category theory, or model theory).

With respect to the current thread on the seven step, this is of
course sort of advanced remarks. But mathematical logic is not an easy
subject. Many things which are not distinguished in the usual practice
of mathematics or physics are distinguished by logicians.

Bruno

http://iridia.ulb.ac.be/~marchal/

Bruno Marchal

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Jun 5, 2009, 11:31:27 AM6/5/09
to everyth...@googlegroups.com

On 05 Jun 2009, at 14:23, ronaldheld wrote:

>
> Bruno:
> I understand a little better. is there a citition for a version of
> Church Thesis that all algorithm can be written in
> FORTRAN?


The original Church Thesis, (also due to Post, Turing, Markov, Kleene,
and others independently)

is this:

A function is computable if and only if it is programmable in LAMDA
CALCULUS.

Then it is an easy but tedious exercise of programing to show that you
can simulate LAMDA CALCULUS with FORTRAN, and that you can simulate
FORTRAN with LAMBDA CALCULUS. So they compute the same functions.

And the same is true with LISP, or JAVA, or ALGOL, or C++, etc... in
the place of FORTRAN.

A thorough introduction to Church thesis, and I would say one far
deeper than usual, is integrally part of the seventh step of UDA. So
we will come back on this soon or later. Church thesis is really the
key and the motor of both UDA and AUDA. I have discovered that it is
rarely well understood, even by many "experts". Like Gödel's theorem,
Church's thesis is often deformed or misused.

Bruno


http://iridia.ulb.ac.be/~marchal/

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