bhobba
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Bohm2 quoted E.T. Jaynes:
'Our present quantum mechanical formalism is not purely epistemological; it is a peculiar mixture describing in part realities of Nature, in part incomplete human information about Nature-all scrambled up by Heisenberg and Bohr into an omelette that nobody has seen how to unscramble. Yet we think that this unscrambling is a pre-requisite for any further advance in basic physical theory'
I most emphatically do NOT agree with that at all. As Ballentine shows it follows from 2 axioms - and to a certain extent the second axiom follows from the first via Gleasons theorem so its really wrapped up in one axiom.
And that axiom has a reasonable justification that goes something like this:
Imagine we have a system and some observational apparatus that has n possible outcomes associated with values yi. This immediately suggests a vector and to bring this out I will write it as Ʃ yi |bi>. Now we have a problem - the |bi> are freely chosen - they are simply man made things that follow from a theorem on vector spaces - fundamental physics can not depend on that. To get around it QM replaces the |bi> by |bi><bi| to give the operator Ʃ yi |bi><bi| - which is basis independent. This is the foundational axiom of QM, and heuristically why its reasonable.
IMHO it is not a mismash of ideas, it is the consequence of one key and very fundamental idea.
What it means is another issue - and that is hotly debated.
But what the theory says, and even why it says it, is IMHO VERY well understood - what it MEANS is what's discussed.
This is what I mean by you really need to read the modern texts on QM like Ballentine that develops it correctly from the modern perspective, then make up your own mind - you will not get it from the commentary of those that may have a different view than what you would form, and may not have even been exposed to the modern approach detailed in Ballentine. I find it VERY hard to believe Jaynes could have a view like that after being exposed to a modern treatment - my understanding is he died in 1998 and his views were probably formed from the early textbooks like Dirac and Von Neumann - things have moved on considerably since then.
In my early exposure to QM I learned it from those two texts - the treatment of Ballentine a WAY WAY ahead of those - but that's only to be expected - we have had many decades of research separating them.
Thanks
Bill
'Our present quantum mechanical formalism is not purely epistemological; it is a peculiar mixture describing in part realities of Nature, in part incomplete human information about Nature-all scrambled up by Heisenberg and Bohr into an omelette that nobody has seen how to unscramble. Yet we think that this unscrambling is a pre-requisite for any further advance in basic physical theory'
I most emphatically do NOT agree with that at all. As Ballentine shows it follows from 2 axioms - and to a certain extent the second axiom follows from the first via Gleasons theorem so its really wrapped up in one axiom.
And that axiom has a reasonable justification that goes something like this:
Imagine we have a system and some observational apparatus that has n possible outcomes associated with values yi. This immediately suggests a vector and to bring this out I will write it as Ʃ yi |bi>. Now we have a problem - the |bi> are freely chosen - they are simply man made things that follow from a theorem on vector spaces - fundamental physics can not depend on that. To get around it QM replaces the |bi> by |bi><bi| to give the operator Ʃ yi |bi><bi| - which is basis independent. This is the foundational axiom of QM, and heuristically why its reasonable.
IMHO it is not a mismash of ideas, it is the consequence of one key and very fundamental idea.
What it means is another issue - and that is hotly debated.
But what the theory says, and even why it says it, is IMHO VERY well understood - what it MEANS is what's discussed.
This is what I mean by you really need to read the modern texts on QM like Ballentine that develops it correctly from the modern perspective, then make up your own mind - you will not get it from the commentary of those that may have a different view than what you would form, and may not have even been exposed to the modern approach detailed in Ballentine. I find it VERY hard to believe Jaynes could have a view like that after being exposed to a modern treatment - my understanding is he died in 1998 and his views were probably formed from the early textbooks like Dirac and Von Neumann - things have moved on considerably since then.
In my early exposure to QM I learned it from those two texts - the treatment of Ballentine a WAY WAY ahead of those - but that's only to be expected - we have had many decades of research separating them.
Thanks
Bill
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