On Wednesday, November 22, 2017 at 2:51:56 PM UTC-7, [email protected] 
wrote:
>
>
> On Wednesday, November 22, 2017 at 5:24:48 PM UTC, Bruno Marchal wrote:
>>
>>
>> On 22 Nov 2017, at 09:55, [email protected] wrote:
>>
>> On Tuesday, November 21, 2017 at 12:43:05 PM UTC-7, Bruno Marchal wrote:
>>>
>>>
>>> On 20 Nov 2017, at 20:40, [email protected] wrote:
>>>
>>> On Monday, November 20, 2017 at 6:56:52 AM UTC-7, Bruno Marchal wrote:
>>>>
>>>>
>>>> On 18 Nov 2017, at 21:32, [email protected] wrote:
>>>>
>>>> On Saturday, November 18, 2017 at 1:17:25 PM UTC-7, Brent wrote:
>>>>>
>>>>>
>>>>>
>>>>> On 11/18/2017 8:58 AM, John Clark wrote:
>>>>>
>>>>> * ​> ​ I think "must" is unwarranted, certainly in the case of the 
>>>>>> MWI. Rather, it ASSUMES all possible measurements must be realized in 
>>>>>> some 
>>>>>> world. ​ ​ **I see no reason for this assumption other than an 
>>>>>> insistence to fully reify the wf in order to avoid "collapse".*
>>>>>>
>>>>>
>>>>> The MWI people don't have to assume anything because 
>>>>> ​there is absolutely nothing in ​t
>>>>> he Schrodinger 
>>>>> ​Wave ​E
>>>>> quation 
>>>>> ​ about collapsing, its the Copenhagen people who have to assume that 
>>>>> somehow it does. ​
>>>>>
>>>>>
>>>>> It's not just an assumption.  It's an observation.  The SE alone 
>>>>> didn't explain the observation, hence the additional ideas.
>>>>>
>>>>> Brent
>>>>>
>>>>
>>>> *Moreover, MWI DOES make additional assumptions, as its name indicates, 
>>>> based on the assumption that all possible measurements MUST be measured, 
>>>> in 
>>>> this case in other worlds. *
>>>>
>>>>
>>>> That is not an assumption. It is the quasi-literal reading of the 
>>>> waves. It is Copenhagen who added an assumption, basically the assumption 
>>>> that the wave does not apply to the observer: they assumed QM was wrong 
>>>> for 
>>>> the macroscopic world (Bohr) or for the conscious mind (Wigner, von 
>>>> Neumann) depending where you put the cut.
>>>>
>>>
>>> *CMIIAW, but I see it, the postulates tell us the possible results of 
>>> measurements. They don't assert that every possible measurement will be 
>>> realized.*
>>>
>>> What do you mean by realize? 
>>>
>>
>>  *Realized = Measured. AG*
>>
>> Measured by who?
>>
>  
Doesn't this identical question come up in MWI, but with Many Worlds the 
problem seems to metastasize. AG

>  
>
>> More precisely, if Alice look at a particle is state up+down: the wave is 
>> A(up + down) = A up + A down. Then A looks at the particles. The waves 
>> evolves into A-saw-up up + A-saw-down down. Are you OK to say that a 
>> measurement has occurred? Copenhagen says that the measurement gives 
>> either A-saw-up up or A-saw-up down, but that NEVER occurs once we abandon 
>> the collapse. So without collapse, a measurement is a first person 
>> experience. In this case, it is arguably the same as the experience of 
>> being duplicated.
>>
>  
If you could revise your reply using the wf of the singlet state (without 
the normalizing factor) in the following form, I might be able to evaluate 
your analysis; namely, ( |UP>|DN> - |DN>|UP> ). *I believe you have 
misapplied tensor linearity.* TIA, AG

> Without collapse, the measurement are described by the quantum laws. 
>>>
>>
>> *That's precisely what QM doesn't describe, which constitutes part of the 
>> measurement problem. AG*
>>
>>
>> Just see above. QM describes precisely why the observers believe 
>> correctly (with respect to their first person notion) having done 
>> measurement, and got precise outcomes, but from the 3p waves perspectives, 
>> all we have is a structured collection of relative states (which all exists 
>> and are structured in arithmetic, BTW).
>>
>> An observer along a superposition up + down, *is* the same state as the 
>>> observer along up superposed with the observer down, if he look in the {up 
>>> + down, up - down} basis, "he" will see he is in up+down, but if he looks 
>>> in the {up down} basis; the observer consciousness differentiate, in his 
>>> first person perspective, but the solution of the wave describes the two 
>>> outcomes realized from the point of view of each observer. You can't decide 
>>> to make one of them into a zombie. 
>>>
>>
>>  *I have no idea what you mean. Please try again. AG*
>>
>> The tensor product is linear, so A(up + down) = (A up) + (A down). OK?
>>
>
But this doesn't appear in singlet state, and I don't see why it is 
relevant. How can an observer can be in a superposed state? It's the system 
which is in a superposed state, which is never observed AFAIK. AG
 

>
>> the evolution is linear and when A looks at the particle: she is 
>> described by (A-up up) + (A-down down).   (with of course 1/sqrt(2) 
>> everywhere).
>>
>> the consciousness of A has differentiated into (A-up) and (A-down). With 
>> Bohr, one among A-up and A-down mysteriously disappears. With Bohm (one 
>> world + a potential simulating the entire Many-world, but "without 
>> particles") one among A-up and A-down becomes a zombie, even one lacking a 
>> body made of particles, yet, the waves describes them as being alive like 
>> you and me, and we can test it (in principle) by making quantum computation 
>> with oneself.
>>
>> *So I see an additional assumption in the MWI.  AG*
>>>
>>> I disagree, and Everett would disagree. I am aware most people claims 
>>> Everett and Copenhagen are differet intepretations, but from a 
>>> metamathematical obvious view: Everett and Copenhagen are different 
>>> theories.
>>>
>>
>> *They have identical postulates but Everett adds another non-trivial one 
>> as I indicated above; namely, that every possible measurement is realized, 
>> that is measured, in another world. I don't see why you insist on denying 
>> something so obvious. AG*
>>
>> ?
>>
>> I think you should read Everett. he propose a new formulation of QM, and 
>> it is copenhagen with the withdrawal of the collapse postulate. 
>>
>
OK, Everett removes collapse, but adds the postulate that every possible 
outcome is measured in some other world. Breathtaking, and as I stated 
above non-trivial. See my remarks in last post to Clark. AG 

>
>> All measurement are realized in the sense that no superposition ever 
>> collapse, but that it looks in that way from the first person perspective 
>> of the observer. he reduces the quantum indeterminacy to the classical 
>> self-indetermination based on amoeba-like duplication. The only problem is 
>> that his task is not finished: by using mechanism (as he recognizes 
>> explicitly in his long text) he must take into account all computations, 
>> not just the quantum one. in other word, the wave itself must be recovered, 
>> and indeed the math indicates that is possible, as quantum logics appears 
>> at the place where such task must be handled. 
>>
>> Everett is the SWE, and Copenhagen is SWE + collapse. We might accept 
>>> that Everett theory has not yet justify all aspects of what could be the 
>>> physical reality (and provably so if we assume digital mechanism in 
>>> cognitive science), but, to be short, it is less crazy than any theory 
>>> making the collapse into a physical phenomenon.
>>>
>>
>>  *Why crazy? What we seem to observe IS collapse;*
>>
>>
>> yes. but that is the whole difference between a platonist and an 
>> aristotelian. The aristotelian define reality by what they see. The 
>> platonist define reality by whatever makes us to believe that we see 
>> something.
>>
>
So by your lights "arithmetic" or "computation" leads us to reality, 
whereas the physical world is an illusion? -- a bold thesis but IMO 
unlikely. AG 

>
>> And we do not observe a collapse/ We observe a cat, or something. Exactly 
>> like the wave without collapse, + a mechanist theory of mind, predicts. 
>>
>> Everett just soleved the mind-body problem, at the conceptual level. And 
>> partially, because my contribution here is that this *has to be* 
>> prolongated in arithmetic, and the wave must be justified itself by a 
>> statistic on all computations. It works at the proposition level: it gives 
>> quantum logic at the place of propositional physics. 
>>
>> * that is, all probabilities evolving to zero except the measured 
>> probability evolving to 1, by an as-yet unknown physical process. AG  *
>>
>> A unknown physical phenomenon that Einstein criticized already in 1927, 
>> by showing that the collapse would need to be non covariant. 
>>
>
Proof? Reference? TY, AG
 

> The wave has to vanish instantaneously. 
>>
>
 If a probability wave is non physical, it could do so without 
contradiction. AG

With the many-worlds, there is no problem at all for the easy 1927 thought 
>> experience: the wave never vanishes, but you localize yourself on which 
>> branch you are in the superposition. 
>>
>> The measurement problem exists only when we associate a unique outcome 
>> for the experiment. With Everett, measurement are explained by 
>> interaction+entanglement. decoherence then explains why we can't see the 
>> "other branches".
>>
>
Unless you can reasonably describe the content of these other worlds, as 
implied by my last post to Clark, you seem to be in a world of hurt (in 
this world btw). AG 

>
>> I know that Bruce and Clark disagree, but in my opinion, Everett 
>> (non-collapse) solves all the conceptual problems that Einstein disliked so 
>> much in QM. We get a reversible deterministic local physical "big picture". 
>>
>> Now, with mechanism, this leads to no universe at all, in the 
>> aristotelian sense of the words, as the "physical universe", the wavy 
>> multiverse of Everett-Deutsch, has to be itself the winner in a deeper game 
>> played by all computations (which exists in elementary arithmetic). "All 
>> computations" is a very solid notions, thanks to Gödel's theorem which 
>> protects Church's thesis and Mechanism from a vast collection of 
>> reductionist philosophy.
>>
>> Bruno
>>
>> *I reject this hypothesis. What I do concede is that in the case of the 
>>>> Multiverse of String Theory, if time is infinite and the possible 
>>>> universes 
>>>> finite -- 10^500 -- all possible universes will be, or have been, 
>>>> realized. 
>>>> AG*
>>>>
>>>>
>>>> OK, but that is not Everett-Deustch "multiverse" (relative state, 
>>>> many-worlds, etc.).
>>>>
>>>
>>> *Too much parsing! I was trying to explain that the Multiverse of String 
>>> Theory is manifestly *different* from the Many Worlds of the MWI. AG *
>>>
>>>
>>> Yes. you are right on this. In string theory with collapse (if this 
>>> could even make sense), you have 10^500 physical realities. In string 
>>> theory without collapse, you have (10^500 * Infinity) physical realities, 
>>> at first sight (with mechanism they are just "coherent dreams" (sigma_1 
>>> true sentences seen in the Bp & ~Bf mode) by Numbers).
>>>
>>> Bruno
>>>
>>

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