On Wednesday, January 9, 2019 at 8:49:41 PM UTC-6, Bruce wrote:
>
> On Thu, Jan 10, 2019 at 1:36 PM John Clark <johnk...@gmail.com 
> <javascript:>> wrote:
>
>> On Wed, Jan 9, 2019 at 7:49 PM Bruce Kellett <bhkel...@gmail.com 
>> <javascript:>> wrote:
>>
>> >>The following 2012 article in Physical Review letters describes a QED 
>>>> calculation involving 12,672 tenth order Feynman diagrams used to 
>>>> calculate both the magnetic moment of the electron and the inverse of the 
>>>> Fine Structure Constant and obtaining a value of 137.035999173 which 
>>>> is almost exactly the same as the experimentally derived value:
>>>>
>>>
>>> >That is an experimentally derived value!!!!!
>>>
>>
>> No,  the experimentally derived value is 137.035999139
>>
>> *>Your original claim was that the fine structure constant was 
>>> computable. *
>>
>>
>> I said that was my intuition, I don't have a proof.   
>>
>> > *it is a physical constant that must be measured.*
>>
>>
>> I know, that's why I said the Fine Structure Constant was defined 
>> physically not mathematically,  and that's why any physical theory that is 
>> in conflict with that measured value for the FSC can not be a good theory. 
>> Feynman's QED is not in conflict with it, in fact it produced the closest 
>> agreement between experiment and theory in the entire history of science.
>>
>> > *But it is not computable from first principles,*  
>>
>>
>> That depends on what the first principle is, if its charged particles 
>> behave the way Feynman said they do then you can compute a value for the 
>> FSC that is very very close to the best measured one. Maybe when 
>> measurement becomes more precise a statistically significant discrepancy 
>> will show up between the experimental value and the theoretical value,
>>
>
> There is no theoretical value". All the values that we have are measured 
> -- often in different ways, or from the results of different experiments to 
> measure the same things, such as g-2, so there can be a range of measured 
> results. The CODATA value is their best-fit value to the whole range of 
> different experimental measurements. But in the final analysis, the fine 
> structure constant is an arbitrary physical constant that must be measured 
> -- there is no "theoretical value".
>
> Bruce
>

Yes and no. The speed of light and Planck's constant for instance are 
measured input. The charge is both measured and estimated with charge 
renormalization. 

LC
 

>
> if so we'll have to fine something better than Feynman Diagrams because in 
>> science when experiment and theory fight experiment always wins.      
>>  
>>
>>> *>You have to define what you mean by "computable". *
>>
>>
>> The Fine Structure Constant is computable if and only if there exists a 
>> finite algorithm that can work on a finite amount of data and produce a 
>> number in a finite amount of time that is arbitrarily close to it.  I don't 
>> claim to have such a algorithm I'm just saying my hunch is it exists and 
>> Feynman gives us reason for optimism. But I could be wrong.    
>>
>

-- 
You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.

Reply via email to