On Friday, April 27, 2018 at 6:02:33 AM UTC-5, Bruce wrote: > > From: 'scerir' via Everything List <everyth...@googlegroups.com > <javascript:>> > > > K. Camilleri wrote a very long paper about 'Constructing the Myth of the > Copenhagen Interpretation'. But there are many **different** versions > on-line. > > https://philpapers.org/rec/CAMCTM > > https://tinyurl.com/y9a9odek > > He points out that the subjectivist view of the role of the observer > (consciousness) is a 'misconception' of the Copenhagen Interpretation. > > 'Although Heisenberg did sometimes speak of a subjective element in > quantum physics, this should not be taken to mean that the consciousness of > the ‘observer’ plays a crucial roe lint eh measurement interaction. In > Physics and Philosophy in 1958, Heisenberg argued that “the transition from > the ‘possible’ to the ‘actual’ takes place during the act of observation” > but this transition occurs “applies to the physical, not the psychical act > of observation”. Only once the “interaction of the object with the > measuring device” has taken place can we speak of the actualization, but > here he was careful to point out that “it is not connected with the act of > registration of the result, by the mind of observer” (Heisenberg, 1958, p. > 54).' > > 'So where did this view come from? And how did this view come to be > associated with the likes of Bohr and Heisenberg? Scholars have often > traced this view to von Neumann’s analysis of measurement in his > Mathematische Grundlagen der Quantenmechanik published in 1932 (von > Neumann, 1955). Whereas in Bohr’s complementarity, the measurement device > is described using the concepts of classical physics, and not according to > the laws of quantum mechanics, in von Neumann’s presentation, the > measurement device is given a quantum-mechanical treatment (Bub, 1995). > According to von Neumann’s formal treatment of the problem, when we observe > a quantum system, there is an instantaneous change of the wave function in > Hilbert space – it collapses – a process which is not described by the > Schrödinger equation. Precisely what von Neumann’s philosophical views on > this matter were is more difficult to judge, though as Becker and Gavroglou > have observed there is no evidence of him endorsing a realist view of the > wave function, nor does he make any explicit reference to the need to > introduce the consciousness of the observer in the measuring chain (Becker, > 2004; Gavroglou, 1995, p. 171).Rather it was the 1939 monograph La Théorie > de l’Observation en Méchanique Quantique by London and Bauer which we find > the first explicit mention of the claim that the reduction of the wave > function was the result of the conscious activity of the human mind > (French, 2002).' > > etc etc > > > Interesting..... I have often thought that Bohr and Heisenberg were not > quite the monsters of positivism that they are often painted as these days. > In fact, I would suggest that the prevalence of decoherence means that a > case can be made that everything is, in practice, classical, and that the > quantum only shows itself reluctantly in the small and the isolated. > Whether that means that the classical is prior -- essential for > understanding the quantum -- is something that can be argued about. But I > do not think that such an idea is entirely silly, and nor can it just be > dismissed out-of-hand. > > The world we know and experience is classical, after all. Else we, as > classical beings, could not experience it! > > Bruce >
It is maybe wrong to say that either the classical or quantum are somehow prior. We are used to thinking of the classical world as being in part built up from the quantum world. We often think of the classical world as a large action or many Planck units of action limit on quantum physics. Yet the relationship between the quantum and classical worlds is a bit strange. Often we quantize a classical field theory. This is certainly the case with QED. though intrinsic spin and Fermi-Dirac fields are not so derived. The question of quantum gravity may well have to do with a question over this; is quantum gravitation a quantization of classical general relativity, or is classical GR some limit of some systems that is entirely different. This connects in many ways the nature of gauge symmetries and entanglement. Gauge symmetries are redundancies, a set of moduli in a space or moduli space are all redundant with respect to field configurations on the base manifold. Entanglements by analogy are a redundancy with respect to the quantum information in states; the change or unitary processing of one state is copied with another. The Copenhagen interpretation is no more insane than many world interpretation. The difference is how one might want to think of the role of entanglement phase. In decoherence we think of entanglement phase, this sort of state redundancy, as diffused into the rest of the world. With black holes we may think of it being surrendered to a black hole, and in many ways black holes involve entanglement as a nonlocal symmetry that can only be controlled (or steered) locally. The locality is a form of gauge-like transformation of entanglement through spacetime. We may in such instances where it is impossible to track the entanglement phase just FAPP say it it lost and go with the CI of Bohr. If one in such circumstances works with MWI there is a far larger amount of "state entanglement accounting" that must be done that can be intractable. LC -- 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.
