On Wednesday, April 20, 2022 at 7:53:33 PM UTC-6 meeke...@gmail.com wrote:

>
>
> On 4/20/2022 6:42 PM, Alan Grayson wrote:
>
>
>
> On Wednesday, April 20, 2022 at 6:14:31 PM UTC-6 Alan Grayson wrote:
>
>> On Wednesday, April 20, 2022 at 5:21:47 PM UTC-6 Alan Grayson wrote:
>>
>>>
>>>
>>> On Friday, April 15, 2022 at 12:41:03 PM UTC-6 meeke...@gmail.com wrote:
>>>
>>>>
>>>>
>>>> On 4/14/2022 2:00 PM, George Kahrimanis wrote:
>>>>
>>>> On Wednesday, April 13, 2022 at 8:55:48 PM UTC+3 meeke...@gmail.com 
>>>> (Brent) wrote:
>>>>
>>>> Decoherence has gone part way in solving the when/where/what basis 
>>>>> questions, but only part way.
>>>>>
>>>>
>>>> As I wrote at the end of my first reply to your message, I share your 
>>>> concern about decoherence but I see the glass as half-full; that is, with 
>>>> a 
>>>> little more subtlety I hope that the matter can be formulated in clear 
>>>> terms.
>>>>
>>>> Surely collapse is easier to handle as a general concept (except, on 
>>>> the other hand, that it requires new dynamics). I forgot to mention that 
>>>> *my 
>>>> argument for deriving the Born Rule works with collapse, too* -- so it 
>>>> is an alternative to Gleason's theorem.
>>>>
>>>> Here I define colapse as an irreversible process, violating unitarity 
>>>> of course, and I keep it separate from randomisation. The latter means 
>>>> that 
>>>> each outcome is somehow randomised -- an assumption we can do without.
>>>>
>>>> *Collapse can also be described in a many-world formulation!* It 
>>>> differs from the no-collapse MWI only in being irreversible. 
>>>>
>>>>
>>>> If you can throw away low probability branches, what's to stop you from 
>>>> throwing away all but one?  You've already broken unitary evolution.  If 
>>>> you read Hardy's axiomatization of QM you see that the difference between 
>>>> QM and classical mechanics turns on a single word in Axiom 5 Continuity: 
>>>> There exists a *continuous *reversible transformation on a system 
>>>> between any two pure states of that system.
>>>>
>>>> My argument in outline is
>>>> 1. assessment that MWI-with-collapse is workable;
>>>> 2. therefore, outcomes of small enough measure can be neglected in 
>>>> practice;
>>>>
>>>>
>>>> Yes, I've wondered if a smallest non-zero probability could be defined 
>>>> consistent with the data.
>>>>
>>>> 3. now Everett's argument can proceed, concluding that the Born Rule is 
>>>> a practically safe assumption (to put it briefly).
>>>>
>>>> So I have replaced two assumptions of Gleason's theorem, randomisation 
>>>> and non-contextuality, by the assessment of workability only.
>>>>
>>>> If you don't feel comfortable yet with formulating collapse in a 
>>>> many-world setting, let us also assume randomisation (God plays dice), for 
>>>> the sake of the argument, in a single-world formulation. That is, we 
>>>> ASSUME 
>>>> the existence of probability; then the previous argument just guarantees 
>>>> that this probability follows the Born Rule.
>>>>
>>>>
>>>> Assume?  Randomness is well motivated by evidence.  And it's more 
>>>> random than just not knowing some inherent variable, because in the EPR 
>>>> experiment a randomized hidden variable can on explain the QM result if 
>>>> it's non-local.
>>>>
>>>
>>>>
>>>>
>>>> Of course I favour the first version of the argument, using the 
>>>> many-world formulation of collapse, to avoid the "God plays dice" 
>>>> nightmare.
>>>>
>>>>
>>>> Why this fear of true randomness?  We have all kinds of classical 
>>>> randomness we just attributed to "historical accident".  Would it really 
>>>> make any difference it were due to inherent quantum randomness?  Albrect 
>>>> and Phillips have made an argument that there is quantum randomness even 
>>>> nominally classical dynamics. https://arxiv.org/abs/1212.0953v3
>>>>
>>>
>>> The authors regard quantum fluctuations as fundamental. How are they 
>>> defined? AG
>>>
>> I think I get it. Whereas before QM we could attribute single, 
>> unpredictABLE outcomes to ignorance of initial conditions, and but with QM 
>> our understanding is augmented; now we can attribute it to ... nothing? AG
>>
> Is that because, if we could attribute a single, unpredictable outccome to 
> ignorance, that would be, defacto, a hidden variable theory? AG 
>
>
> Roughtly, yes.  That's what a hidden variable is, a value that if you knew 
> it you could predict the outcome.
>
> Brent
>
 
Why the quaified "yes"? Does Bell's theorem exclude ignorance as a hidden 
variable? AG

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