Quantum Reality by Jim Baggott

Author:Jim Baggott [Baggott, Jim]
Language: eng
Format: epub
ISBN: 9780192565839
Publisher: OUP Oxford
Published: 2020-03-04T00:00:00+00:00

7

Quantum Mechanics is Incomplete

So We Need to Add Some Things

Statistical Interpretations Based on Local and Crypto Non-local Hidden Variables

Chapters 5 and 6 summarize interpretations of quantum mechanics that follow from the legacy of Copenhagen. They are based on a set of metaphysical preconceptions that tend to side with the anti-realism of Bohr and (especially) Heisenberg, based on the premise that quantum mechanics is complete. In the inaccessible quantum world we’ve finally run up against the boundary between things-in-themselves and things-as-they-appear that philosophers have been warning us about for centuries. We have to come to terms with the fact that there’s nothing to see here, and we’ve reached the end of the road.

But this anti-realist perspective is not to everybody’s taste, as theorist John Bell made all too clear in 1981:1

Making a virtue of necessity, and influenced by positivistic and instrumentalist philosophies, many came to hold not only that it is difficult to find a coherent picture but that it is wrong to look for one—if not actually immoral then certainly unprofessional.

If we make the philosophical choice to side with Einstein, Schrödinger, and Popper and adopt a more realist position, this means we can’t help but indulge our inner metaphysician. We can’t help speculating about a reality beyond the empirical data, a reality lying beneath the things-as-they-appear. We must admit that quantum mechanics is incomplete, and be ready to make frequent visits to the shores of Metaphysical Reality in the hope of finding something—anything—that might help us to complete it.

In doing this we might be led astray, but I honestly think that it goes against the grain of human nature not to try.

Opening the door to realism immediately puts us right back in a fine mess. Any realist interpretation, reformulation, or extension of quantum mechanics necessarily drags along with it all the associated metaphysical preconceptions about how reality ought to be. It must address all the bizarre things that quantum physics appears to allow, such as superpositions now involving real physical states (rather than coded information), the instantaneous collapse of the wavefunction, and the spooky action at a distance this would seem to imply. It has to explain away or eliminate the randomness and discontinuity inherent in quantum mechanics and restore some sense of continuity and cause-and-effect, presided over by a God free of a gambling addiction. It has to find a way to make the quantum world compatible with the classical world, explaining or avoiding an arbitrary ‘shifty split’ between the two.

Where do we start?

In his debate with Bohr and his correspondence with Schrödinger, Einstein had hinted at a statistical interpretation. In his opinion, quantum probabilities, derived as the squares of the wavefunctions,* actually represent statistical probabilities, averaged over large numbers of physically real particles. We resort to probabilities because we’re ignorant of the properties and behaviours of the physically real quantum things. This is very different from anti-realist interpretations which resort to probabilities based on previous experience because we can say nothing meaningful about any of the underlying physics.

Einstein toyed with just such an approach in May 1927.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.