On Tuesday, December 5, 2017 at 7:57:57 AM UTC, agrays...@gmail.com wrote:
>
>
>
> On Tuesday, December 5, 2017 at 5:32:22 AM UTC, agrays...@gmail.com wrote:
>>
>>
>>
>> On Tuesday, December 5, 2017 at 3:59:19 AM UTC, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Tuesday, December 5, 2017 at 12:50:54 AM UTC, Bruce wrote:
>>>>
>>>> On 5/12/2017 11:38 am, agrays...@gmail.com wrote:
>>>>
>>>> On Tuesday, December 5, 2017 at 12:26:58 AM UTC, Bruce wrote: 
>>>>>
>>>>> On 5/12/2017 3:15 am, Bruno Marchal wrote: 
>>>>> > On 01 Dec 2017, at 01:49, Bruce Kellett wrote: 
>>>>> >> On 1/12/2017 8:57 am, Bruce Kellett wrote: 
>>>>> >>> On 1/12/2017 4:21 am, Bruno Marchal wrote: 
>>>>> >>>> On 29 Nov 2017, at 23:16, Bruce Kellett wrote: 
>>>>> >>>> On 30/11/2017 2:24 am, Bruno Marchal wrote: 
>>>>> >>>>>> On 29 Nov 2017, at 04:59, Bruce Kellett wrote: 
>>>>> >>>>>> 
>>>>> >>>>>>> I would suggest that there is no such world. Whether a coin 
>>>>> >>>>>>> comes up head or tails on a simple toss is not a quantum 
>>>>> event; 
>>>>> >>>>>>> it is determined by quite classical laws of physics governing 
>>>>> >>>>>>> initial conditions, air currents and the like. 
>>>>> >>>>>> 
>>>>> >>>>>> It depends. If you shake the coin long enough, the quantum 
>>>>> >>>>>> uncertainties can add up to the point that the toss is a 
>>>>> quantum 
>>>>> >>>>>> event. With some student we have evaluate this quantitavely (a 
>>>>> >>>>>> long time ago) and get that if was enough to shake the coin 
>>>>> less 
>>>>> >>>>>> than a minute, but more than few seconds ... (Nothing 
>>>>> rigorous). 
>>>>> >>>>> 
>>>>> >>>>> That is a misunderstanding of quantum randomness. For the 
>>>>> outcome 
>>>>> >>>>> of a coin toss to be determined by quantum randomness, we would 
>>>>> >>>>> have to have a single quantum event where the outcome was 
>>>>> >>>>> amplified by decoherence so that it was directly entangled with 
>>>>> >>>>> the way the coin landed. Schematically: 
>>>>> >>>>> 
>>>>> >>>>>  |quantum event>|coin> = (|outcome A> + |outcome B>)|coin> 
>>>>> >>>>>  = (|outcome A>|coin heads> + |outcome B>|coin tails>) 
>>>>> >>>> 
>>>>> >>>> The coin is quantum. 
>>>>> >>> 
>>>>> >>> The coin is classical, consisting of something of the order of 
>>>>> 10^22 
>>>>> >>> atoms. Indeterminacy in position as given by the Heisenberg 
>>>>> >>> Uncertainty Principle, is undetectably small. 
>>>>> >> 
>>>>> >> I think it is worth while to put some (approximate) numbers around 
>>>>> >> this. The reduced Planck constant, h-bar, is approximately 10^{-27} 
>>>>> >> g.cm^2/s. The Uncertainty Principle is 
>>>>> >> 
>>>>> >>    delta(x)*delta(p) >= h-bar/2. 
>>>>> >> 
>>>>> >> For a coin weighing approximately 10 g and moving at 1 cm/s, the 
>>>>> >> momentum is mv = 10 g.cm/s. Taking the momentum uncertainty to be 
>>>>> of 
>>>>> >> this order, the uncertainty in position, delta(x) is of the order 
>>>>> of 
>>>>> >> 10^{-28} cm. A typical atom has a diameter of about 10^{-8} cm, so 
>>>>> >> the uncertainty in position is approximately 20 orders of magnitude 
>>>>> >> less than the atomic diameter. 
>>>>> > 
>>>>> > I think that is enough to get the macroscopic superposition, as, 
>>>>> like 
>>>>> > I explained, you have to take into account not just the quantum 
>>>>> > indeterminacy, + the classical chaos. You might need to shake for 
>>>>> some 
>>>>> > minutes. 
>>>>>
>>>>> You could shake for longer than the age of the universe and you will 
>>>>> still not convert quantum uncertainties and classical thermal motions 
>>>>> into a macroscopic superposition. Do you know nothing about coherence? 
>>>>> And the fact that coherent phases between the components are what 
>>>>> separates a superposition from a mixture?
>>>>
>>>>
>>>> Are the phase angles of components of a superposition identical? If so, 
>>>> is this the definition of coherence? TIA, AG
>>>>
>>>>
>>>> No, why should they be equal. You really do have to learn some basic 
>>>> quantum mechanics, Alan, and stop bothering the list with such questions.
>>>>
>>>> Bruce
>>>>
>>>
>>> Was I bothering the list when I started this thread, and others? I 
>>> recall from class the answer is NO, because the probabilities are 
>>> unaffected when taking complex conjugates (ignoring interference), but 
>>> other comments on Avoid2 for example, when I was a member, indicated 
>>> otherwise. Also, the poster here you're replying to seemed not to 
>>> understand as well. Next time take THAT into account. AG 
>>>
>>
>> I took a few graduate courses in QM at major US universities and do not 
>> recall any discussion about coherent states of superposition when solving 
>> the SWE or Dirac's equation. Maybe the universities in Australia do a 
>> better job. I suggest you be more tolerant in the future, notwithstanding 
>> the burden that your knowledge of these subjects places on your karma. And 
>> keep in mind that I am responsible the interactions you are now enjoying. 
>> That should count for something. Don't ya think? FWIW, I initially left 
>> Avoid2 because of the abuse. AG 
>>
>
> All I can recall about the phase factor in QM is that it's arbitrary, 
> insofar as whatever value is chosen doesn't effect the result of Born's 
> rule. I suppose that makes me a moron from the pov of an expert. The 
> implication was, for me, that it can't be explicitly calculated. Hence, my 
> question. AG
>

To wrap it up, if the phase factor is arbitrary, which is what my professor 
indicated, it's puzzling how a sum of solutions as a superposition could 
have fixed relations among those factors to yield a coherent wf.  I may not 
be the brightest bulb in the room when it comes to QM, but a dumb question 
it is NOT. AG

>
>
>>>> Random quantum uncertainties 
>>>>> and thermal motions are not coherent, so cannot form superpositions. 
>>>>>
>>>>

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