Re: Why is Church's thesis a Miracle?

[Bruce Kellett]

From: *Bruno Marchal* mailto:marc...@ulb.ac.be>>
On 26 Sep 2018, at 02:36, Bruce Kellett > wrote:


I agree that the quote does not make sense. But it is what you said.


It does not make sense out of hits context. It is the the “…” which 
does not make sense.


The real question is “have you grasped now?”

I say that in the context of Mechanism. Then in the math part, I 
have (semi-) exiomatize consciousness as
True, unjustifiable, undefinable, immediately knowable, indubitable, 
and show how the modes of self-reference makes any universal machine 
verifying the existence of this.


This is an attempt at proof by definition. All it amounts to is your 
usual "cat-dog" logic -- the argument that similarity implies identity.


The question is “do you accept that your daughter marry a man who get 
a digital heart, and later, a digital brain”?


My daughter can marry whomsoever she pleases.

No-one says that similarity implies identity, but only that we make 
the hypothesis that there is a level of description where digital 
similarity entails practical survival.


Nobody defends the idea that this is true (except Clark).

I just deduce from that that the materialist argument invoking a 
physical universe to get a brain-mind identity thesis is no more 
valid, and that the computationalist has to derive physics from 
self-reference.


Your deduction fails.


You must study before criticising.


Only some level of study is necessary. Enough to know that you do not 
make your case.



A proof conveys truth only in so far as the axioms/assumptions that 
were assumed at the start are true.


Proof in general does not entails truth.


I did not say that it did. Read what I say, and do not misquote me
I said that proof conveys truth only in so far as the axioms are true.


That is what is not provable by any machine about a truth enough large 
to encompass itself.


The machine does not have to prove this -- it is manifest that a valid 
proof is "truth conserving", it does not entail truth.






Your proof assumes arithmetical realism (platonism).


Yes, that means it assumes that classical logic can be applied in 
elementary arithmetic. That is presupposed in *all* papers in the 
physics literature, and elsewhere.


Now you are getting ridiculous. Elementary arithmetic, such as 2+2=4, 
is tautologically true.


It is true, but it needs a non purely logical theory to be proved. You 
cannot drive the numbers from logic alone.


Who claims that you can?  Whitehead and Russell tried, but failed.



So arithmetic is used in physics, but that does not mean that anyone 
necessarily assumes arithmetic


Anyone capable to take a bus to go to an exam of math, like already in 
primary school, assumes arithmetic.


I would suggest that you follow your own advice and not quote out of 
context! Or jump into the middle of a sentence and treat it as though 
that were the whole sentence. You might show me the courtesy of 
responding to what I actually say, not some straw man.


I said that no one necessarily assumes arithmetical realism, or platonism.


We are blase. And we learn by examples, so we forget that we build on 
assumption, but everyone capable of adding and multiplying, and 
believing in notion like “anniversary” assumes arithmetic. Quantum 
physics, the theory, assumes arithmetic. The definition of a digital 
machine assumes arithmetic.


These thing use arithmetic -- that does not entail assuming arithmetical 
realism.




You don’t seem to be aware that we can be skeptical about an 
ontological physical reality.


But if you want matter, no problem. Given that you seem to disbelieve 
Mechanism. You are pertly coherent, but I doubt you are interested in 
mind, souls, and the origin of the physical realm.


I am interested enough. But that does not mean that I have to accept 
your account. I assume a mind-brain connection, so that mind and 
consciousness are purely physical things. They do not depend on some 
independently existing magical arithmetical realm. As Brent says, there 
is no "hard problem of consciousness". It is purely an engineering 
problem. Once we have built conscious robots we will wonder what all the 
fuss was about.




If you are prepared to say yes to the doctor, then you must believe 
that the body and brain are Turing emulable,


At some relevant level. Some might ask for the atomic level, other for 
the string level, etc.



and /ipso facto/, that consciousness is Turing emulable.


That is a subtle point. It is correct from the third person view, but 
consciousness is not emulate by the physical things,


I suggest that you try and prove that. And while you are at it, prove 
that you are fully conscious under anaesthetic.




I might not say yes to the doctor for other reasons, but I certainly 
believe in strong AI, i.e., that consciousness is recoverable in a 
Turing machine.


Nice. That is enough to listen to those machines, and they will 
explain to 

Re: The codical-material universe

[John Clark]

On Tue, Sep 25, 2018 at 1:24 PM Bruno Marchal  wrote:

*>If someone else can explain the problem that John Clark see, let him or
> her helps him.*
>

So even the originator of the theory can't make sense out of it and asks
third parties to figure out exactly what the question asked of the guy in
Helsinki on Monday is that is supposed to be refuted on Tuesday. You keep
telling us what the question is not but you never said what the question
IS. And yes you say the question is about various sorts of peepee but I
don't want to know what the question is about either, I want to know THE
EXACT WORDING of the question asked of the guy on Monday and the exact
wording of the answer, and I want all of this done without personal
pronouns that do nothing but hide major blunders in your logic.

I want that but I won't get that because you can't do that because your
theory is so bad it's not even wrong.

> *All points below have been answered,*
>

Except for who the referent is for all those personal pronouns you love to
throw around so loberally and  what the question asked in Helsinki is, not
what it isn't, not what it's about, but exactly what IS it.

> *I think John Clark do just very bad philosophy, asking impossible but
> irrelevant precision,*
>

And so we have the sorry spectacle of a logician who likes to sprinkle
formal equations in his posts complaining that I'm being too precise when
all I ask is the meaning of a few pronoun and the wording of the question
you keep talking about.

John K Clark
>
>
>

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Re: Why is Church's thesis a Miracle?

[Bruno Marchal]

> On 26 Sep 2018, at 02:36, Bruce Kellett  wrote:
> 
> From: Bruno Marchal mailto:marc...@ulb.ac.be>>
>>> On 24 Sep 2018, at 02:25, Bruce Kellett >> > wrote:
>>> 
>>> From: Bruno Marchal mailto:marc...@ulb.ac.be>>
 
> On 23 Sep 2018, at 13:10, Bruce Kellett  > wrote:
> 
> From: Bruno Marchal mailto:marc...@ulb.ac.be>>
>>> On 23 Sep 2018, at 08:53, Bruce Kellett >> > wrote:
>>> 
>>> From: Bruno Marchal mailto:marc...@ulb.ac.be>>
 
 I would say that mechanism explains rather well consciousness, through 
 computer science and the logic of self-reference ((which basically 
 predict consciousness (indubitable, non provable and non definable 
 sort of knowledge),
>>> 
>>> With that sort of logic
>> 
>> Only standard classical logic is used in the derivation. + some 
>> hypothesis.
>> 
>>> I can prove that my cat is a dog:
>>> My cat has four legs and a tail; dogs have four legs and a tail; so my 
>>> cat is a dog.
>> 
>> That is invalid in all logic. I was not arguing, just remind the work 
>> already done. The proof is longer, OBVIOUSLY. It shows that you have not 
>> read the papers.
> 
> No, you use exactly this logic all the time. You find some superficial 
> similarity between things and then conclude that they are identical.
 
 Could you be specific? Did you read my papers?
>>> 
>>> Quoting from above: "...the logic of self-reference basically predict 
>>> consciousness…."
>> 
>> That quote is too short to make sense.
> 
> I agree that the quote does not make sense. But it is what you said.

It does not make sense out of hits context. It is the the “…” which does not 
make sense. 

The real question is “have you grasped now?”



> 
>> I say that in the context of Mechanism. Then in the math part, I have 
>> (semi-) exiomatize consciousness as
>> True, unjustifiable, undefinable, immediately knowable, indubitable, and 
>> show how the modes of self-reference makes any universal machine verifying 
>> the existence of this.
> 
> This is an attempt at proof by definition. All it amounts to is your usual 
> "cat-dog" logic -- the argument that similarity implies identity.

The question is “do you accept that your daughter marry a man who get a digital 
heart, and later, a digital brain”?

No-one says that similarity implies identity, but only that we make the 
hypothesis that there is a level of description where digital similarity 
entails practical survival. 

Nobody defends the idea that this is true (except Clark). 

I just deduce from that that the materialist argument invoking a physical 
universe to get a brain-mind identity thesis is no more valid, and that the 
computationalist has to derive physics from self-reference.

You must study before criticising. 





> 
> 
> Showing that the logic of self reference has some similarities with 
> consciousness is not sufficient.
 
 Sufficient for what? I think you attribute me things I do not say.
>>> 
>>> Sufficient to explain consciousness. I quote what you say…
>> 
>> Qouting is not enough. You must study and understand the theory before. If 
>> you don’t understand, ask a question.
> 
> If you do not accept quotes of your own words as evidence, then we are in a 
> sorry position……

I don’t accept quote out of the context. I reminded you of the context. You 
seem to be the one talking like he knew some truth. In metaphysics, that makes 
you invalid at the start.






> 
 I start from a precise hypothesis, then all what I say is first derive 
 informally, and then formally, using rather standard definition.
 
> You have to show me a logic that has a coherent internal narrative and 
> shows the signs of consciousness that I use to conclude that other people 
> (and cats and dogs) are conscious.
 
 ?
 
 I will only give you a proof that any machine claiming such a proof is 
 inconsistent.
 
 I assume mechanism (the invariant of consciousness fr some 
 transformation), and derive from that, constructively, the appearances, 
 including the physical appearances, so that we can test.
>>> 
>>> Proof is a formal concept.
>> 
>> Both the notion of informal proof and formal proof are axiomatised in my 
>> work. Indeed they correspond to the modes axiomatised by []p 
>> & p, and []p. The first one is defined in term of arithmetical relations 
>> that the subject concerned cannot formalised (like truth, if you have heard 
>> of Tarski theorem). 
>> 
>>> A proof conveys truth only in so far as the axioms/assumptions that were 
>>> assumed at the start are true. 
>> 
>> Proof in general does not entails truth.
> 
> I did not say that it did. Read what I say, and do not misquote me
> I said that proof conveys truth only in so far 

Re: Why is Church's thesis a Miracle?

[Philip Thrift]

On Wednesday, September 26, 2018 at 11:46:51 AM UTC-5, Bruno Marchal wrote:
>
>
> On 25 Sep 2018, at 21:20, Philip Thrift > 
> wrote:
>
>
>
> On Tuesday, September 25, 2018 at 12:01:22 PM UTC-5, Bruno Marchal wrote:
>>
>>
>> On 25 Sep 2018, at 15:35, Philip Thrift  wrote:
>>
>>
>>
>> On Tuesday, September 25, 2018 at 7:12:13 AM UTC-5, Bruno Marchal wrote:
>>>
>>>
>>> On 24 Sep 2018, at 07:28, Philip Thrift  wrote:
>>>
>>>
>>>
>>> On Sunday, September 23, 2018 at 10:55:52 AM UTC-5, Bruno Marchal wrote:


 On 23 Sep 2018, at 13:37, Philip Thrift  wrote:



 On Sunday, September 23, 2018 at 4:41:56 AM UTC-5, Bruno Marchal wrote:
>
>
> On 23 Sep 2018, at 09:00, Philip Thrift  wrote:
>
>
>
> On Sunday, September 23, 2018 at 1:28:02 AM UTC-5, Bruno Marchal wrote:
>>
>>
>> On 22 Sep 2018, at 11:40, Philip Thrift  wrote:
>>
>>
>>
>> On Saturday, September 22, 2018 at 2:48:15 AM UTC-5, Bruno Marchal 
>> wrote:
>>>
>>>
>>> On 21 Sep 2018, at 19:55, John Clark  wrote:
>>>
>>>
>>>
>>>
>>> On Wed, Sep 19, 2018 at 7:20 PM Philip Thrift  
>>> wrote:
>>>
>>> >> Mind is what a brain does

  

>>> >*And walking and running is what the legs do. *
 *There is no "walking" like some Platonic immaterial universal 
 except for some pair of legs to be doing it.*

>>>
>>> Right, there is no thinking without a brain (biological or 
>>> electronic) to do it.
>>>
>>>
>>> Assuming your ontological commitment, but that is pseudo-religion. 
>>>
>>> Or equivalently: you confuse matter and primitive matter. Nobody 
>>> doubt that to have human or biological consciousness, we need a human 
>>> brain 
>>> or some electronic device, but that is irrelevant. 
>>>
>>> What has been proved, (see Kleene’s 1952 book) is that the 
>>> arithmetical reality emulates all computations. No need of any more 
>>> assumption than Church thesis and the very elementary arithmetic.
>>>
>>> But an ontological physical reality is only metaphysical speculation 
>>> or hypothesis, and in our setting it is invalid to use it as a 
>>> counter-argument. The most you can do, if you really want to take your 
>>> ontology for granted, is to reject Digital Mechanism or to find a 
>>> mistake 
>>> in my argument, without using your ontological commitment (which would 
>>> beg 
>>> the question).
>>>
>>> Up to now, you have failed to that.
>>>
>>> Bruno
>>>
>>>
>>>
>> It still seems to me that consciousness itself could be an argument 
>> against a purely information-based ontology. ("Information" meaning 
>> based 
>> purely on numbers, combinators, etc.)
>>
>> Philip Goff and Michael Shermer discussed basically this:
>>
>>
>> https://scottbarrykaufman.com/podcast/solving-the-mysteries-of-consciousness-free-will-and-god-with-michael-shermer-and-philip-goff/
>>  
>>
>> via  https://twitter.com/Philip_Goff/status/1043053992916467714
>>
>> (In there there is an about 1 hour podcast.)
>>
>>
>>
>> My summary (fits in a tweet) of Goff:
>>
>> "Physicalism, based on pure informationality (quantitative states and 
>> language} is not sufficient to explain consciousness,  but a materialism 
>> (one greater than physicalism) that is based on experientiality 
>> (qualitative states and language) in addition to informationality, may 
>> be.”
>>
>>
>>
>>
>> That is short. You might elaborate. I can refer you to my papers 
>> which shows that you cannot have both materialism/physicalism and 
>> Mechanism. Many believe that materialism and mechanism go well together, 
>> but they are logically incompatible. With mechanism, physics is reduced 
>> to 
>> arithmetic “seen from inside”.
>>
>> I would say that mechanism explains rather well consciousness, 
>> through computer science and the logic of self-reference ((which 
>> basically 
>> predict consciousness (indubitable, non provable and non definable sort 
>> of 
>> knowledge), but with the price of forcing to drive the physical 
>> appearance 
>> from that theory of consciousness.
>>
>> Bruno
>>
>>
> That was my reply in a tweet to Goff's [ 
> https://twitter.com/Philip_Goff/status/1043053992916467714 ] to 
> summarize in my own words the Goff view.
>
> I elaborate further in my previous post here on *Realistic 
> Computationalism*:
>
>
>  
> https://groups.google.com/d/msg/everything-list/ZDKbxJuQYt4/Z7C1ePCzAwAJ
>  
>
>
> By Pure Computationalism [ 
> https://plato.stanford.edu/entries/computation-physicalsystems ] I 
> mean that everything
>
>
> Which everything? 

Re: Gene Drive and morality

[John Clark]

On Wed, Sep 26, 2018 at 3:04 AM Russell Standish 
wrote:

> *It's not morality, but the precautionary principle in action.*


Every single year you delay doing this you will be condemning 725,000
people to die from malaria and other diseases and incapacitate hundreds of
millions more for weeks at a time. This is caution?


>
>
> *I> t's one thing to show this works within a lab. But causing the
> extinction of a species in an ecosystem can cause an avalanche of knockon
> effects, which generally speaking, cannot be tested for in the lab.*


I can't claim there is zero risk if we do this, there is just no way we can
live in a zero risk world. So we must use judgement. I know of two facts
that you can use to make your judgement:

1) If you decide to do this there is a possibility some species of birds
that eat mosquitoes might be harmed.

2) If you decide not to do this there is a certainty you will be sentencing
725,000 people to die each and every year.

I believe the rational judgement that needs to be made in this case is
obvious.


> >
> *I would be in favour of a moratorium until such time as the ecosystem is
> studied in detail, and detailed simulation models of the ecosystem run.*


That day will never ever come! There will never come a time when self
proclaimed protectors of the environment will say "OK enough simulations
have been done and you've convinced me, lets do it" just as the will never
be a day when the ESP fans will say " I'm seen enough well conducted
studies with negative results to convince me that ESP is not worth pursuing
further and we should move on to studying something new with more potential
to find something interesting". Environmentalists and ESP fans will ALWAYS
demand just one more study before moving on.

>
> *Let's not go into this blind as so often we've done before - eg the story
> of the release of the rabbit calixi virus in Australia.*
>

If that virus saved 725,000 people from death every year I'd call it an
enormous triumph regardless of the harm it caused to pet rabbits in
Australia.

John K Clark

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Re: Why is Church's thesis a Miracle?

[Bruno Marchal]

> On 25 Sep 2018, at 21:20, Philip Thrift  wrote:
> 
> 
> 
> On Tuesday, September 25, 2018 at 12:01:22 PM UTC-5, Bruno Marchal wrote:
> 
>> On 25 Sep 2018, at 15:35, Philip Thrift > 
>> wrote:
>> 
>> 
>> 
>> On Tuesday, September 25, 2018 at 7:12:13 AM UTC-5, Bruno Marchal wrote:
>> 
>>> On 24 Sep 2018, at 07:28, Philip Thrift > wrote:
>>> 
>>> 
>>> 
>>> On Sunday, September 23, 2018 at 10:55:52 AM UTC-5, Bruno Marchal wrote:
>>> 
 On 23 Sep 2018, at 13:37, Philip Thrift > wrote:
 
 
 
 On Sunday, September 23, 2018 at 4:41:56 AM UTC-5, Bruno Marchal wrote:
 
> On 23 Sep 2018, at 09:00, Philip Thrift > wrote:
> 
> 
> 
> On Sunday, September 23, 2018 at 1:28:02 AM UTC-5, Bruno Marchal wrote:
> 
>> On 22 Sep 2018, at 11:40, Philip Thrift > wrote:
>> 
>> 
>> 
>> On Saturday, September 22, 2018 at 2:48:15 AM UTC-5, Bruno Marchal wrote:
>> 
>>> On 21 Sep 2018, at 19:55, John Clark > wrote:
>>> 
>>> 
>>> 
>>> 
>>> On Wed, Sep 19, 2018 at 7:20 PM Philip Thrift > 
>>> wrote:
>>> 
>>> >> Mind is what a brain does
>>>  
>>> >And walking and running is what the legs do. 
>>> There is no "walking" like some Platonic immaterial universal except 
>>> for some pair of legs to be doing it.
>>> 
>>> Right, there is no thinking without a brain (biological or electronic) 
>>> to do it.
>> 
>> Assuming your ontological commitment, but that is pseudo-religion. 
>> 
>> Or equivalently: you confuse matter and primitive matter. Nobody doubt 
>> that to have human or biological consciousness, we need a human brain or 
>> some electronic device, but that is irrelevant. 
>> 
>> What has been proved, (see Kleene’s 1952 book) is that the arithmetical 
>> reality emulates all computations. No need of any more assumption than 
>> Church thesis and the very elementary arithmetic.
>> 
>> But an ontological physical reality is only metaphysical speculation or 
>> hypothesis, and in our setting it is invalid to use it as a 
>> counter-argument. The most you can do, if you really want to take your 
>> ontology for granted, is to reject Digital Mechanism or to find a 
>> mistake in my argument, without using your ontological commitment (which 
>> would beg the question).
>> 
>> Up to now, you have failed to that.
>> 
>> Bruno
>> 
>> 
>> 
>> It still seems to me that consciousness itself could be an argument 
>> against a purely information-based ontology. ("Information" meaning 
>> based purely on numbers, combinators, etc.)
>> 
>> Philip Goff and Michael Shermer discussed basically this:
>> 
>> https://scottbarrykaufman.com/podcast/solving-the-mysteries-of-consciousness-free-will-and-god-with-michael-shermer-and-philip-goff/
>>  
>> 
>>  
>> 
>> via  https://twitter.com/Philip_Goff/status/1043053992916467714 
>> 
>> 
>> (In there there is an about 1 hour podcast.)
>> 
>> 
>> 
>> My summary (fits in a tweet) of Goff:
>> 
>> "Physicalism, based on pure informationality (quantitative states and 
>> language} is not sufficient to explain consciousness,  but a materialism 
>> (one greater than physicalism) that is based on experientiality 
>> (qualitative states and language) in addition to informationality, may 
>> be.”
> 
> 
> 
> That is short. You might elaborate. I can refer you to my papers which 
> shows that you cannot have both materialism/physicalism and Mechanism. 
> Many believe that materialism and mechanism go well together, but they 
> are logically incompatible. With mechanism, physics is reduced to 
> arithmetic “seen from inside”.
> 
> I would say that mechanism explains rather well consciousness, through 
> computer science and the logic of self-reference ((which basically 
> predict consciousness (indubitable, non provable and non definable sort 
> of knowledge), but with the price of forcing to drive the physical 
> appearance from that theory of consciousness.
> 
> Bruno
> 
> 
> That was my reply in a tweet to Goff's [ 
> https://twitter.com/Philip_Goff/status/1043053992916467714 
>  ] to 
> summarize in my own words the Goff view.
> 
> I elaborate further in my previous post here on Realistic 
> Computationalism:
> 
> 
>  
> https://groups.google.com/d/msg/everything-list/ZDKbxJuQYt4/Z7C1ePCzAwAJ 
> 
>  
> 
> 
> By Pure Computationalism 

Re: Probability in MWI as self-locating uncertainty

[Brent Meeker]

On 9/21/2018 9:38 PM, Bruce Kellett wrote:

From: *Brent Meeker* mailto:meeke...@verizon.net>>


On Friday, September 21, 2018 at 12:11:01 AM UTC-5, Bruce Kellett 
wrote:


Adrian Kent (arXiv:1408.1944) makes some interesting comments
about the recent argument by Sebens and Carroll
(arXiv:1405.7577) that probability in MWI can be understood in
terms of self-locating uncertainty -- when all outcomes of a
measurement are realized in unitary quantum mechanics,
probabilities might arise because one is does not know in which
branch of the universal wave function one is located. Kent
points out that this raises questions about how branches are
formed in unitary quantum mechanics.

The usual Everettian argument is that when one measures a state
with two possible outcomes, say a spin-1/2 particle, unitary
evolution takes the states representing the apparatus, observer,
and environment to a FAPP orthogonal set of states branched
according to each of the possible measurement results.
Schematically, one writes the interaction with

   |psi> = (|+> + |->)/sqrt(2)

as |psi>|O>, where O is the "ready" state of the observer
(including apparatus and environment). Thus:

  (|+> + |->)|O>

At this point there is just one observer who has not become
entangled with the apparatus or the rest of the environment. To
take this to the next stage, Kent points out that we use the
distribution law of algebra to eliminate the above brackets, and
write



It seems that you are treating this mathematical rewriting as a 
physical process.  Why insert it between
(|+> + |->)|O>  and |+>|O+> + |->|O->   and create the appearance of 
a problem?


There is a lacuna in the physical narrative at this point. Each 
component of the superposition acts on the apparatus/observer in the 
same 'ready' state in order to get |O+> as different from |O->. This 
differentiation must take place before decoherence acts to diagonalize 
the density matrix. Otherwise all terms in the density matrix would be 
the same and there would be no distinction between outcomes. You can't 
just paper over this explanatory gap by calling it a mathematical 
rewriting.


I think the problem arises from the use of the term "observer" which 
implies a kind of sharp "now it's observed".  The way I look at is it 
explained by this diagram for an EPR type experiment.  There is a source 
of entangled particles, the red blob, they propagate out to detectors, 
diamonds, and at the detectors decoherence starts and essentially is 
propagated futureward in the blue and yellow light-cones.  The 
observers, Alice and Bob, enter those forward light cones at the stars.  
They are then within the lightcone of one of the detectors and so they 
could observe the result, but whether they look or not they are 
decohered because they are interacting with the branch of decohered 
worlds corresponding to what that detector detected.  The split is 
illustrated as the cone rising above and below the original spacetime 
plane.  On the top side the detectors are A-up, B-up and below the plane 
A-dwn, B-dwn.




So showing the observer and being duplicated before interaction is 
wrong.  They are duplicated when the decohere, whether they "observe" 
anything or not.


Brent



Bruce





Brent



   |+>|O> + |->|O>  (O is uncertain which result he will see)

which, by unitary evolution, becomes entangled with the rest of
the wave function:

  |+>|O+> + |->|O->  ( O has a definite result>

representing observers who record '+' or '-' results,
respectively. Before the last step, the observer does not know
which branch he is on, hence the self-locating uncertainty that
is presumed to be the origin of quantum probabilities.

But Kent points out that there is a problem with this -- in the
line in which O is uncertain, the observer has already split:
there is a copy on each branch of the wave function, even though
the observer has not yet interacted with the apparatus or the
environment, so what caused the observer to split and appear on
both branches in this way? We have used the distribution law of
algebra to expand the brackets in such as way as to naively
indicate that such a split has taken place. But how does this
actually happen, physically? Above we are just talking about
equations -- these have to be related to the physics in some
unambiguous way.

Kent comments on the problem that this causes for the Sebens and
Carroll idea of probability as self-locating uncertainty. But it
would seem that the problem is deeper than this. We commonly
divide the Hilbert space into the tensor product of subspaces
representing the apparatus and the environment, as well as the
observer. Then unitary evolution is supposed to act on each
component of this product space so that, ultimately, decoherence
renders the 

Re: Why is Church's thesis a Miracle?

[Philip Thrift]

On Tuesday, September 25, 2018 at 7:36:48 PM UTC-5, Bruce wrote:
>
> Elementary arithmetic, such as 2+2=4, is tautologically true. In other 
> words, if is true by virtue of the meaning of the terms involved. It has no 
> ontological content outside itself. So arithmetic is used in physics, but 
> that does not mean that anyone necessarily assumes arithmetic realism, or 
> platonism. Mathematics is used because it is useful, not because it is true 
> in any sense other than tautologically.
>
> Arithmetic (and, indeed, all of mathematics) can be regarded as a formal 
> system, with a number of defined symbols and rules of inference. Any 
> sequence of the allowed symbols can be written down. Any such sequence is a 
> theorem if it can be derived from the basic axioms using the allowed rules 
> of inference. If it cannot be so derived, it is not a theorem. The status 
> of some sequences of symbols may be undecidable; and some sequences may be 
> true for other reasons, even though they are not theorems. There is little 
> else to mathematics than this.
>
> Bruce
>

When the subject of 'what is mathematics' comes up, I say now "It's a genre 
of fiction, maybe the most useful one." In the context of what's true, like 
the recent Michael Atiyah proof (or many say not-proof) of the Riemann 
Hypothesis, and in another case of the abc conjecture [ 
https://www.quantamagazine.org/titans-of-mathematics-clash-over-epic-proof-of-abc-conjecture-20180920/
 
], I say "If it isn't formalized in and proven in Coq yet, it's not true."

Take 2+2=4. A proof in Coq: [ 
https://brilliant.org/discussions/thread/2-2-4-in-coq/ ].

This is  "What's true in mathematics is just what some computer outputs."

And that's that. :)

- pt



 

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Re: Gene Drive and morality

[Russell Standish]

On Tue, Sep 25, 2018 at 12:08:10PM -0400, John Clark wrote:
> 
> Mosquitoes carry many diseases, malaria alone killed 450,000 people last year
> and made many millions more very sick, nevertheless self styled guardians of
> morality are already calling for a moratorium on the use of this technology in
> the field and say we should wait decades before letting one of these insects 
> go
> free if we ever do.
> 
> If that's morality then I'm proud to be immoral.
>  

It's not morality, but the precautionary principle in action. It's one
thing to show this works within a lab. But causing the extinction of a
species in an ecosystem can cause an avalanche of knockon effects,
which generally speaking, cannot be tested for in the lab. I would be
in favour of a moratorium until such time as the ecosystem is studied
in detail, and detailed simulation models of the ecosystem run. Let's
not go into this blind as so often we've done before - eg the story of
the release of the rabbit calixi virus in Australia.


-- 


Dr Russell StandishPhone 0425 253119 (mobile)
Principal, High Performance Coders
Visiting Senior Research Fellowhpco...@hpcoders.com.au
Economics, Kingston University http://www.hpcoders.com.au


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