Is quantum mechanics an understood theory?

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Discussion Overview

The discussion revolves around the understanding of quantum mechanics (QM) as a theory. Participants explore whether leading physicists comprehend the nature of QM and the implications of statements made by Richard Feynman regarding the understanding of QM.

Discussion Character

  • Philosophical inquiry
  • Debate/contested

Main Points Raised

  • Some participants suggest that understanding QM is subjective and that while its postulates lead to accurate predictions, the deeper meaning behind these postulates remains elusive.
  • One participant argues that QM is not a complete theory, implying that understanding it does not equate to understanding the quantum universe as a whole.
  • Another participant posits that a better theory is needed to explain why QM makes accurate predictions, noting that no such theory currently exists.
  • Some participants reference Feynman's assertion that no one truly understands what happens between state preparation and measurement in QM.
  • There is a reiteration of the need for clarity in what is meant by "understand," indicating that definitions may vary among participants.

Areas of Agreement / Disagreement

Participants express differing views on the nature of understanding in relation to QM, with no consensus reached on whether QM is fully understood or what constitutes understanding in this context.

Contextual Notes

The discussion highlights the philosophical nature of understanding scientific theories and the complexities involved in defining what it means to "understand" a theory like QM.

scope
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hi,

i wonder if QM is a theory that is understood?. For example do leading physicists understand why QM is like it is?
I remember that Feynman said that nobody understands QM, is that statement true?
 
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Note first that this is a philosophical question, not a scientific one per se; and further that 'understood' is entirely subjective. QM is well understood in terms of accepting its postulates and knowing how they lead to the accepted results... I don't think anyone can really 'understand' postulates in the first place however. Does anyone even understand why classical physics "is like it is?" Does anyone understand 'why' F = ma (besides tautologically)? Or 'why' F_c = q\vec{v} \times \vec{B} ?

Also keep in mind that QM isn't a complete theory, so understanding 'it' isn't the same as understanding the quantum universe.

For anyone to answer more accurately, I think you would have to be more specific about what you're asking, or what you're looking for.
 
The only thing that can tell us why QM makes such accurate predictions about the results of experiments...is a better theory. (There are only two kinds of answers to questions about reality: theories and garbage). No better theory is known to exist.

There are examples in physics of how one theory "explains" why another is accurate. The best one is probably general relativity and its explanation of why Newton's theory of gravity is so accurate.

QM is very well understood. What Feynman meant was almost certainly that no one understands what "actually happens" to a system between state preparation and measurement.
 
scope said:
hi,

i wonder if QM is a theory that is understood?. For example do leading physicists understand why QM is like it is?
I remember that Feynman said that nobody understands QM, is that statement true?

Understood:
fully apprehended as to purport or meaning or explanation.

i don't think so...
 
scope said:
hi,

i wonder if QM is a theory that is understood?. For example do leading physicists understand why QM is like it is?
I remember that Feynman said that nobody understands QM, is that statement true?
This might help:
http://xxx.lanl.gov/abs/quant-ph/0609163 [Found.Phys.37:1563-1611,2007]
 
scope said:
hi,

i wonder if QM is a theory that is understood?. For example do leading physicists understand why QM is like it is?
I remember that Feynman said that nobody understands QM, is that statement true?


“...I think I can safely say that nobody understands quantum mechanics. ...Do
not keep saying to yourself, if you can possibly avoid it, ‘But how can it be like
that?’ because you will get ‘down the drain’, into a blind alley from which
nobody has yet escaped. Nobody knows how it can be like that...”
 
It depends on what you mean by "understand".
 
Dr Lots-o'watts said:
It depends on what you mean by "understand".


read man, read...


yoda jedi said:
Understood:
fully apprehended as to purport or meaning or explanation.
 

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