The magical "Born Rule" & quantum "measurement": Implications for Physics (original) (raw)

The Magical "Born Rule" and Quantum "Measurement": Implications for Physics

Foundations, 2023

I. The arena of quantum mechanics and quantum field theory is the abstract, unobserved and unobservable, M-dimensional formal Hilbert space ≠ spacetime. II. The arena of observations—and, more generally, of all events (i.e., everything) in the real physical world—is the classical four-dimensional physical spacetime. III. The “Born rule” is the random process “magically” transforming I into II. Wavefunctions are superposed and entangled only in the abstract space I, never in spacetime II. Attempted formulations of quantum theory directly in real physical spacetime actually constitute examples of “locally real” theories, as defined by Clauser and Horne, and are therefore already empirically refuted by the numerous tests of Bell’s theorem in real, controlled experiments in laboratories here on Earth. Observed quantum entities (i.e., events) are never superposed or entangled as they: (1) exclusively “live” (manifest) in real physical spacetime and (2) are not described by entangled wavefunctions after “measurement” effectuated by III. When separated and treated correctly in this way, a number of fundamental problems and “paradoxes” of quantum theory vs. relativity (i.e., spacetime) simply vanish, such as the black hole information paradox, the infinite zero-point energy of quantum field theory and the quantization of general relativity.

Quantum probabilities from quantum entanglement: experimentally unpacking the Born rule

New Journal of Physics, 2016

The Born rule, a foundational axiom used to deduce probabilities of events from wavefunctions, is indispensable in the everyday practice of quantum physics. It is also key in the quest to reconcile the ostensibly inconsistent laws of the quantum and classical realms, as it confers physical significance to reduced density matrices, the essential tools of decoherence theory. Following Bohr's Copenhagen interpretation, textbooks postulate the Born rule outright. However, recent attempts to derive it from other quantum principles have been successful, holding promise for simplifying and clarifying the quantum foundational bedrock. A major family of derivations is based on envariance, a recently discovered symmetry of entangled quantum states. Here, we identify and experimentally test three premises central to these envariance-based derivations, thus demonstrating, in the microworld, the symmetries from which the Born rule is derived. Further, we demonstrate envariance in a purely local quantum system, showing its independence from relativistic causality.

Can we escape from Bell's conclusion that quantum mechanics describes a non-local reality

Studies in History and Philosophy of Modern Physics, 1996

It is argued that for a proper understanding of the question of nonlocality in quantum mechanics and hidden variables theories purporting to reproduce the quantum mechanical measurement results, it is essential to consider stochastic hidden variables theories. conclusion that in derivations of the Bell inequality an implicit assumption of locality is made, is shown to be a consequence of his restriction to deterministic hidden variables theories. It is also demonstrated how it is possible to draw a clear distinction between contextualism and non-objectivism, nonobjectivism amounting to the impossibility of reducing an individual quantum mechanical measurement result, either in a deterministic or in a stochastic way, to the hidden variables state the individual object is in independently of the measurement. The analogy with thermodynamics is exploited to clarify the issue.

Interpretations of quantum mechanics, and interpretations of violation of Bell's inequality

2001

The discussion of the foundations of quantum mechanics is complicated by the fact that a number of different issues are closely entangled. Three of these issues are i) the interpretation of probability, ii) the choice between realist and empiricist interpretations of the mathematical formalism of quantum mechanics, iii) the distinction between measurement and preparation. It will be demonstrated that an interpretation of violation of Bell's inequality by quantum mechanics as evidence of non-locality of the quantum world is a consequence of a particular choice between these alternatives. Also a distinction must be drawn between two forms of realism, viz. a) realist interpretations of quantum mechanics, b) the possibility of hidden-variables (sub-quantum) theories.

Quantum mechanics and the manifestation of the world

Quantum Studies: Mathematics and Foundations, 2014

Quantum theory's irreducible empirical core is a probability calculus. While it presupposes the events to which (and on the basis of which) it serves to assign probabilities, and therefore cannot account for their occurrence, it has to be consistent with it. It must make it possible to identify a system of observables that have measurementindependent values.What makes this possible is the incompleteness of the spatiotemporal differentiation of the physical world. This is shown by applying a novel interpretive principle to interfering alternatives involving distinctions between regions of space. Applying the same interpretive principle to alternatives involving distinctions between things makes it safe to claim that the macroworld comes into being through a progressive differentiation of a single, intrinsically undifferentiated entity. By entering into reflexive spatial relations, this entity gives rise to (1) what looks like a multiplicity of relata if the reflexive quality of the relations is not taken into account, and (2) what looks like a substantial expanse if the spatial quality of the relations is reified. The necessary distinction between two domains (classical and quantum, or macro and micro) and their mutual dependence is best understood as a distinction between the manifested world and its manifestation. Keywords Localizable particles • Macroscopic objects • Manifestation • Measurement problem • Spacetime Paper presented at Berge Fest, a conference celebrating the 60th birthday of Berge Englert (Centre for Quantum Technologies,

Quantum Mechanics on a Space and Time Foundation

The possibility of explaining quantum phenomena on a spatial-temporal foundation is developed further. Motivation for this alternative investigation has its origins in the EPR paradox. Analysis of Bell inequalities identified the assumption of metric variable-type for physical quantities, additional to that of local causality. Similar analysis is extended to EPR-steering, Hardy non-locality and the more recently introduced Cabello quantum contextuality inequalities. The same algebraic assumption is present in these later configurations. Because of the nexus between variable-type and underlying geometry, and by implication space structure, violation of EPR experiments can be attributed to space being non-metric. Analysis of Heisenberg gedanken experiments leads to the same conclusion. Quantum mechanics, including also QFT, is then foundationally explainable in terms of space, time and geometry consistent with relativity.

A Local Interpretation of Quantum Mechanics

Foundations of Physics, 2015

It is shown that Quantum Mechanics is ambiguous when predicting relative frequencies for an entangled system if the measurements of both subsystems are performed in spatially separated events. This ambiguity gives way to unphysical consequences: the projection rule could be applied in one or the other temporal(?) order of measurements (being non local in any case), but symmetry of the roles of both subsystems would be broken. An alternative theory is presented in which this ambiguity does not exist. Observable relative frequencies differ from those of orthodox Quantum Mechanics, and a gendaken experiment is proposed to falsify one or the other theory. In the alternative theory, each subsystem has an individual state in its own Hilbert space, and the total system state is direct product (rank one) of both, so there is no entanglement. Correlation between subsystems appears through a hidden label that prescribes the output of arbitrary hypothetical measurements. Measurement is treated as a usual reversible interaction, and this postulate allows to determine relative frequencies when the value of a magnitude is known without in any way perturbing the system, by measurement of the correlated companion. It is predicted the existence of an accompanying system, the de Broglie wave, introduced in order to preserve the action reaction principle in indirect measurements, when there is no interaction of detector and particle. Some action on the detector, different from the one cause by a particle, should be observable.

A Realist Analysis of Six Controversial Quantum Issues

Mario Bunge: A Centenary Festschrift, 2019

This paper presents a philosophically realistic analysis of quantization, field-particle duality, superposition, entanglement, nonlocality, and measurement. These are logically related: Realistically understanding measurement depends on realistically understanding superposition, entanglement, and nonlocality; understanding these three depends on understanding field-particle duality and quantization. This paper resolves all six, based on a realistic view of standard quantum physics. It concludes that, for these issues, standard quantum physics is consistent with scientific practice since Copernicus: Nature exists on its own and science's goal is to understand its operating principles, which are independent of humans. Quantum theory need not be regarded as merely the study of what humans can know about the microscopic world, but can instead view it as the study of real quanta such as electrons, photons, and atoms. This position has long been argued by Mario Bunge.