
#37
Dec712, 06:09 PM

Sci Advisor
PF Gold
P: 2,066

I believe decoherence solves the measurement problem for all practical purposes, meaning no experiment can ever show that you can't assume the pure state has been transformed into a mixed state and that the combined system and measurement apparatus is in the state it is observed to be prior to observation. You may not like that particular view because it doesn't explain how the state is selected or exactly where the collapse occurred, or even why there is any measurement outcome at all, but logically it is unassailable. It is purely a matter of philosophical debate rather than any kind of objective 'truth' if it has a flaw. Most certainly it whispers in your ear something more is going on and we like would a way of explaining the 'gaps' but whispering in your ear and actually being a flaw are not the same thing. Thanks Bill 



#38
Dec712, 06:46 PM

Mentor
P: 6,044

Steven Weinberg has written graduatelevel quantum mechanics book that has just been published,
http://www.amazon.com/LecturesQuant...4926966&sr=12 and in it, Weinberg says ""My own conclusion (not universally shared) is that today there is no interpretation of quantum mechanics that does not have serious flaws, and that we ought to take seriously the possibility of finding some more satisfactory other theory, to which quantum mechanics is merely a good approximation."" 



#39
Dec712, 06:54 PM

Sci Advisor
PF Gold
P: 2,066

Of course Weinberg is worthy of respect  but he does not speak for all physicists. If QM is flawed is purely a matter of opinion  not actual fact. My view is QM whispers in your ear there is something more going on  but that is far from it being a fact. Thanks Bill 



#40
Dec712, 07:26 PM

P: 887

what I find interesting is that the Schrodinger Equation does not look like a wave equation; it has a 1st order derivative to time, but 2nd order to position. That to me looks like a diffusion equation. Does that have any significance?




#41
Dec712, 07:46 PM

PF Gold
P: 670

The Quantum as an Emergent System http://www.nonlinearstudies.at/files/ggEmerQuM.pdf http://arxiv.org/ftp/arxiv/papers/1004/1004.4596.pdf A lot of this group's work and most of their publications can be found here: http://www.nonlinearstudies.at/ 



#42
Dec812, 05:16 AM

P: 584

As for Many Worlds … (I know about quantum information theory even less than about Many Worlds:) ) On the one hand, I am no fan of this interpretation, on the other hand, it is my understanding that it puts more emphasis on unitary evolution, whereas the status of the theory of measurements is somewhat lower there than in Copenhagen. And that may be a strong point of Many Worlds, in my book, as I think the contradiction between unitary evolution and the theory of measurements should be resolved in favor of unitary evolution. 



#43
Dec812, 09:08 PM

P: 584





#44
Dec812, 10:18 PM

P: 584





#45
Dec912, 12:32 PM

P: 640





#46
Dec912, 12:35 PM

P: 640





#47
Dec912, 07:47 PM

P: 584





#48
Dec1012, 06:12 AM

P: 640





#49
Dec1012, 06:48 AM

P: 584





#50
Dec1012, 08:21 AM

P: 640

By the way, I've seen several threads on PF about the mystery of the big bang, e.g., how do we have conservation of energy!? But, again, one has to understand GR is a 4D solution, so not all points on the spacetime manifold need possess a "history," and the big bang is just such a point  there is no (3+1)D timeevolved story to tell about the "cause" of the big bang. Thus, this "mystery" results from an inappropriate desire to tell dynamical stories where they're just not applicable. 



#51
Dec1312, 12:45 AM

P: 158

http://www.cambridge.org/us/knowledg...US&code=L2TIQM Also see my website, transactionalinterpretation.org, for introductory and preview material. 



#52
Dec1612, 10:14 AM

P: 584




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