Many Worlds? an Introduction
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Divine Action and the World of Science: What Cosmology and Quantum Physics Teach Us About the Role of Providence in Nature 247 Bruce L
Journal of Biblical and Theological Studies JBTSVOLUME 2 | ISSUE 2 Christianity and the Philosophy of Science Divine Action and the World of Science: What Cosmology and Quantum Physics Teach Us about the Role of Providence in Nature 247 Bruce L. Gordon [JBTS 2.2 (2017): 247-298] Divine Action and the World of Science: What Cosmology and Quantum Physics Teach Us about the Role of Providence in Nature1 BRUCE L. GORDON Bruce L. Gordon is Associate Professor of the History and Philosophy of Science at Houston Baptist University and a Senior Fellow of Discovery Institute’s Center for Science and Culture Abstract: Modern science has revealed a world far more exotic and wonder- provoking than our wildest imaginings could have anticipated. It is the purpose of this essay to introduce the reader to the empirical discoveries and scientific concepts that limn our understanding of how reality is structured and interconnected—from the incomprehensibly large to the inconceivably small—and to draw out the metaphysical implications of this picture. What is unveiled is a universe in which Mind plays an indispensable role: from the uncanny life-giving precision inscribed in its initial conditions, mathematical regularities, and natural constants in the distant past, to its material insubstantiality and absolute dependence on transcendent causation for causal closure and phenomenological coherence in the present, the reality we inhabit is one in which divine action is before all things, in all things, and constitutes the very basis on which all things hold together (Colossians 1:17). §1. Introduction: The Intelligible Cosmos For science to be possible there has to be order present in nature and it has to be discoverable by the human mind. -
Quantum Theory Cannot Consistently Describe the Use of Itself
ARTICLE DOI: 10.1038/s41467-018-05739-8 OPEN Quantum theory cannot consistently describe the use of itself Daniela Frauchiger1 & Renato Renner1 Quantum theory provides an extremely accurate description of fundamental processes in physics. It thus seems likely that the theory is applicable beyond the, mostly microscopic, domain in which it has been tested experimentally. Here, we propose a Gedankenexperiment 1234567890():,; to investigate the question whether quantum theory can, in principle, have universal validity. The idea is that, if the answer was yes, it must be possible to employ quantum theory to model complex systems that include agents who are themselves using quantum theory. Analysing the experiment under this presumption, we find that one agent, upon observing a particular measurement outcome, must conclude that another agent has predicted the opposite outcome with certainty. The agents’ conclusions, although all derived within quantum theory, are thus inconsistent. This indicates that quantum theory cannot be extrapolated to complex systems, at least not in a straightforward manner. 1 Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland. Correspondence and requests for materials should be addressed to R.R. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:3711 | DOI: 10.1038/s41467-018-05739-8 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-018-05739-8 “ 1”〉 “ 1”〉 irect experimental tests of quantum theory are mostly Here, | z ¼À2 D and | z ¼þ2 D denote states of D depending restricted to microscopic domains. Nevertheless, quantum on the measurement outcome z shown by the devices within the D “ψ ”〉 “ψ ”〉 theory is commonly regarded as being (almost) uni- lab. -
Dynamical Relaxation to Quantum Equilibrium
Dynamical relaxation to quantum equilibrium Or, an account of Mike's attempt to write an entirely new computer code that doesn't do quantum Monte Carlo for the first time in years. ESDG, 10th February 2010 Mike Towler TCM Group, Cavendish Laboratory, University of Cambridge www.tcm.phy.cam.ac.uk/∼mdt26 and www.vallico.net/tti/tti.html [email protected] { Typeset by FoilTEX { 1 What I talked about a month ago (`Exchange, antisymmetry and Pauli repulsion', ESDG Jan 13th 2010) I showed that (1) the assumption that fermions are point particles with a continuous objective existence, and (2) the equations of non-relativistic QM, allow us to deduce: • ..that a mathematically well-defined ‘fifth force', non-local in character, appears to act on the particles and causes their trajectories to differ from the classical ones. • ..that this force appears to have its origin in an objectively-existing `wave field’ mathematically represented by the usual QM wave function. • ..that indistinguishability arguments are invalid under these assumptions; rather antisymmetrization implies the introduction of forces between particles. • ..the nature of spin. • ..that the action of the force prevents two fermions from coming into close proximity when `their spins are the same', and that in general, this mechanism prevents fermions from occupying the same quantum state. This is a readily understandable causal explanation for the Exclusion principle and for its otherwise inexplicable consequences such as `degeneracy pressure' in a white dwarf star. Furthermore, if assume antisymmetry of wave field not fundamental but develops naturally over the course of time, then can see character of reason for fermionic wave functions having symmetry behaviour they do. -
The Consistent Histories Approach to the Stern-Gerlach Experiment
The Consistent Histories Approach to the Stern-Gerlach Experiment Ian Wilson An undergraduate thesis advised by Dr. David Craig submitted to the Department of Physics, Oregon State University in partial fulfillment of the requirements for the degree BSc in Physics Submitted on May 8, 2020 Acknowledgments I would like to thank Dr. David Craig, for guiding me through an engaging line of research, as well as Dr. David McIntyre, Dr. Elizabeth Gire, Dr. Corinne Manogue and Dr. Janet Tate for developing the quantum curriculum from which this thesis is rooted. I would also like to thank all of those who gave me the time, space, and support I needed while writing this. This includes (but is certainly not limited to) my partner Brooke, my parents Joy and Kevin, my housemate Cheyanne, the staff of Interzone, and my friends Saskia, Rachel and Justin. Abstract Standard quantum mechanics makes foundational assumptions to describe the measurement process. Upon interaction with a “classical measurement apparatus”, a quantum system is subjected to postulated “state collapse” dynamics. We show that framing measurement around state collapse and ill-defined classical observers leads to interpretational issues, and artificially limits the scope of quantum theory. This motivates describing measurement as a unitary process instead. In the context of the Stern-Gerlach experiment, the measurement of an electron’s spin angular momentum is explained as the entanglement of its spin and position degrees of freedom. Furthermore, the electron-environment interaction is also detailed as part of the measurement process. The environment plays the role of a record keeper, establishing the “facts of the universe” to make the measurement’s occurrence objective. -
Theoretical Physics Group Decoherent Histories Approach: a Quantum Description of Closed Systems
Theoretical Physics Group Department of Physics Decoherent Histories Approach: A Quantum Description of Closed Systems Author: Supervisor: Pak To Cheung Prof. Jonathan J. Halliwell CID: 01830314 A thesis submitted for the degree of MSc Quantum Fields and Fundamental Forces Contents 1 Introduction2 2 Mathematical Formalism9 2.1 General Idea...................................9 2.2 Operator Formulation............................. 10 2.3 Path Integral Formulation........................... 18 3 Interpretation 20 3.1 Decoherent Family............................... 20 3.1a. Logical Conclusions........................... 20 3.1b. Probabilities of Histories........................ 21 3.1c. Causality Paradox........................... 22 3.1d. Approximate Decoherence....................... 24 3.2 Incompatible Sets................................ 25 3.2a. Contradictory Conclusions....................... 25 3.2b. Logic................................... 28 3.2c. Single-Family Rule........................... 30 3.3 Quasiclassical Domains............................. 32 3.4 Many History Interpretation.......................... 34 3.5 Unknown Set Interpretation.......................... 36 4 Applications 36 4.1 EPR Paradox.................................. 36 4.2 Hydrodynamic Variables............................ 41 4.3 Arrival Time Problem............................. 43 4.4 Quantum Fields and Quantum Cosmology.................. 45 5 Summary 48 6 References 51 Appendices 56 A Boolean Algebra 56 B Derivation of Path Integral Method From Operator -
Discerning “Indistinguishable” Quantum Systems
Discerning \indistinguishable" quantum systems Adam Caulton∗ Abstract In a series of recent papers, Simon Saunders, Fred Muller and Michael Seevinck have collectively argued, against the folklore, that some non-trivial version of Leibniz's principle of the identity of indiscernibles is upheld in quantum mechanics. They argue that all particles|fermions, paraparti- cles, anyons, even bosons|may be weakly discerned by some physical re- lation. Here I show that their arguments make illegitimate appeal to non- symmetric, i.e. permutation-non-invariant, quantities, and that therefore their conclusions do not go through. However, I show that alternative, sym- metric quantities may be found to do the required work. I conclude that the Saunders-Muller-Seevinck heterodoxy can be saved after all. Contents 1 Introduction 2 1.1 Getting clear on Leibniz's Principle . 2 1.2 The folklore . 4 1.3 A new folklore? . 5 2 Muller and Saunders on discernment 6 2.1 The Muller-Saunders result . 6 2.2 Commentary on the Muller-Saunders proof . 8 ∗c/o The Faculty of Philosophy, University of Cambridge, Sidgwick Avenue, Cambridge, UK, CB3 9DA. Email: [email protected] 1 3 Muller and Seevinck on discernment 10 3.1 The Muller-Seevinck result . 10 3.2 Commentary on the Muller-Seevinck result . 12 4 A better way to discern particles 14 4.1 The basic idea . 14 4.2 The variance operator . 14 4.3 Variance provides a discerning relation . 16 4.4 Discernment for all two-particle states . 18 4.5 Discernment for all many-particle states . 22 5 Conclusion 24 1 Introduction 1.1 Getting clear on Leibniz's Principle What is the fate of Leibniz's Principle of the Identity of Indiscernibles for quantum mechanics? It depends, of course, on how the Principle is translated into modern (enough) parlance for the evaluation to be made. -
Reformulating Bell's Theorem: the Search for a Truly Local Quantum
Reformulating Bell's Theorem: The Search for a Truly Local Quantum Theory∗ Mordecai Waegelly and Kelvin J. McQueenz March 2, 2020 Abstract The apparent nonlocality of quantum theory has been a persistent concern. Einstein et. al. (1935) and Bell (1964) emphasized the apparent nonlocality arising from entanglement correlations. While some interpretations embrace this nonlocality, modern variations of the Everett-inspired many worlds interpretation try to circumvent it. In this paper, we review Bell's \no-go" theorem and explain how it rests on three axioms, local causality, no superdeterminism, and one world. Although Bell is often taken to have shown that local causality is ruled out by the experimentally confirmed entanglement correlations, we make clear that it is the conjunction of the three axioms that is ruled out by these correlations. We then show that by assuming local causality and no superdeterminism, we can give a direct proof of many worlds. The remainder of the paper searches for a consistent, local, formulation of many worlds. We show that prominent formulations whose ontology is given by the wave function violate local causality, and we critically evaluate claims in the literature to the contrary. We ultimately identify a local many worlds interpretation that replaces the wave function with a separable Lorentz-invariant wave-field. We conclude with discussions of the Born rule, and other interpretations of quantum mechanics. Contents 1 Introduction 2 2 Local causality 3 3 Reformulating Bell's theorem 5 4 Proving Bell's theorem with many worlds 6 5 Global worlds 8 5.1 Global branching . .8 5.2 Global divergence . -
Consistent Histories
Chapter 12 Local Weak Property Realism: Consistent Histories Earlier, we surmised that weak property realism can escape the strictures of Bell’s theorem and KS. In this chapter, we look at an interpretation of quantum mechanics that does just that, namely, the Consistent Histories Interpretation (CH). 12.1 Consistent Histories The basic idea behind CH is that quantum mechanics is a stochastic theory operating on quantum histories. A history a is a temporal sequence of properties held by a system. For example, if we just consider spin, for an electron a history could be as follows: at t0, Sz =1; at t1, Sx =1; at t2, Sy = -1, where spin components are measured in units of h /2. The crucial point is that in this interpretation the electron is taken to exist independently of us and to have such spin components at such times, while in the standard view 1, 1, and -1 are just experimental return values. In other words, while the standard interpretation tries to provide the probability that such returns would be obtained upon measurement, CH provides the probability Pr(a) that the system will have history a, that is, such and such properties at different times. Hence, CH adopts non-contextual property realism (albeit of the weak sort) and dethrones measurement from the pivotal position it occupies in the orthodox interpretation. To see how CH works, we need first to look at some of the formal features of probability. 12.2 Probability Probability is defined on a sample space S, the set of all the mutually exclusive outcomes of a state of affairs; each element e of S is a sample point to which one assigns a number Pr(e) satisfying the axioms of probability (of which more later). -
High Energy Physics Quantum Information Science Awards Abstracts
High Energy Physics Quantum Information Science Awards Abstracts Towards Directional Detection of WIMP Dark Matter using Spectroscopy of Quantum Defects in Diamond Ronald Walsworth, David Phillips, and Alexander Sushkov Challenges and Opportunities in Noise‐Aware Implementations of Quantum Field Theories on Near‐Term Quantum Computing Hardware Raphael Pooser, Patrick Dreher, and Lex Kemper Quantum Sensors for Wide Band Axion Dark Matter Detection Peter S Barry, Andrew Sonnenschein, Clarence Chang, Jiansong Gao, Steve Kuhlmann, Noah Kurinsky, and Joel Ullom The Dark Matter Radio‐: A Quantum‐Enhanced Dark Matter Search Kent Irwin and Peter Graham Quantum Sensors for Light-field Dark Matter Searches Kent Irwin, Peter Graham, Alexander Sushkov, Dmitry Budke, and Derek Kimball The Geometry and Flow of Quantum Information: From Quantum Gravity to Quantum Technology Raphael Bousso1, Ehud Altman1, Ning Bao1, Patrick Hayden, Christopher Monroe, Yasunori Nomura1, Xiao‐Liang Qi, Monika Schleier‐Smith, Brian Swingle3, Norman Yao1, and Michael Zaletel Algebraic Approach Towards Quantum Information in Quantum Field Theory and Holography Daniel Harlow, Aram Harrow and Hong Liu Interplay of Quantum Information, Thermodynamics, and Gravity in the Early Universe Nishant Agarwal, Adolfo del Campo, Archana Kamal, and Sarah Shandera Quantum Computing for Neutrino‐nucleus Dynamics Joseph Carlson, Rajan Gupta, Andy C.N. Li, Gabriel Perdue, and Alessandro Roggero Quantum‐Enhanced Metrology with Trapped Ions for Fundamental Physics Salman Habib, Kaifeng Cui1, -
Quantum Trajectories for Measurement of Entangled States
Quantum Trajectories for Measurement of Entangled States Apoorva Patel Centre for High Energy Physics, Indian Institute of Science, Bangalore 1 Feb 2018, ISNFQC18, SNBNCBS, Kolkata 1 Feb 2018, ISNFQC18, SNBNCBS, Kolkata A. Patel (CHEP, IISc) Quantum Trajectories for Entangled States / 22 Density Matrix The density matrix encodes complete information of a quantum system. It describes a ray in the Hilbert space. It is Hermitian and positive, with Tr(ρ)=1. It generalises the concept of probability distribution to quantum theory. 1 Feb 2018, ISNFQC18, SNBNCBS, Kolkata A. Patel (CHEP, IISc) Quantum Trajectories for Entangled States / 22 Density Matrix The density matrix encodes complete information of a quantum system. It describes a ray in the Hilbert space. It is Hermitian and positive, with Tr(ρ)=1. It generalises the concept of probability distribution to quantum theory. The real diagonal elements are the classical probabilities of observing various orthogonal eigenstates. The complex off-diagonal elements (coherences) describe quantum correlations among the orthogonal eigenstates. 1 Feb 2018, ISNFQC18, SNBNCBS, Kolkata A. Patel (CHEP, IISc) Quantum Trajectories for Entangled States / 22 Density Matrix The density matrix encodes complete information of a quantum system. It describes a ray in the Hilbert space. It is Hermitian and positive, with Tr(ρ)=1. It generalises the concept of probability distribution to quantum theory. The real diagonal elements are the classical probabilities of observing various orthogonal eigenstates. The complex off-diagonal elements (coherences) describe quantum correlations among the orthogonal eigenstates. For pure states, ρ2 = ρ and det(ρ)=0. Any power-series expandable function f (ρ) becomes a linear combination of ρ and I . -
Historical Parallels Between, and Modal Realism Underlying Einstein and Everett Relativities
Historical Parallels between, and Modal Realism underlying Einstein and Everett Relativities Sascha Vongehr National Laboratory of Solid-State Microstructures, Nanjing University, Nanjing 210093, P. R. China A century ago, “ past ” and “ future ”, previously strictly apart, mixed up and merged. Temporal terminology improved. Today, not actualized quantum states, that is merely “ possible ” alternatives, objectively “exist ” (are real) when they interfere. Again, two previously strictly immiscible realms mix. Now, modal terminology is insufficient. Both times, extreme reactions reach from rejection of the empirical science to mystic holism. This paper shows how progress started with the relativization of previously absolute terms, first through Einstein’s relativity and now through Everett’s relative state description, which is a modal realism. The historical parallels suggest mere relativization is insufficient. A deformation of domains occurs: The determined past and the dependent future were restricted to smaller regions of space-time. This ‘light cone description’ is superior to hyperspace foliations and already entails the modal realism of quantum mechanics. Moreover, an entirely new region, namely the ‘absolute elsewhere’ was identified. The historical precedent suggests that modal terminology may need a similar extension. Discussing the modal realistic connection underlying both relativities, Popper’s proof of future indeterminism is turned to shatter the past already into many worlds/minds, thus Everett relativity is merely the -
DECOHERENCE AS a FUNDAMENTAL PHENOMENON in QUANTUM DYNAMICS Contents 1 Introduction 152 2 Decoherence by Entanglement with an En
DECOHERENCE AS A FUNDAMENTAL PHENOMENON IN QUANTUM DYNAMICS MICHAEL B. MENSKY P.N. Lebedev Physical Institute, 117924 Moscow, Russia The phenomenon of decoherence of a quantum system caused by the entangle- ment of the system with its environment is discussed from di®erent points of view, particularly in the framework of quantum theory of measurements. The selective presentation of decoherence (taking into account the state of the environment) by restricted path integrals or by e®ective SchrÄodinger equation is shown to follow from the ¯rst principles or from models. Fundamental character of this phenomenon is demonstrated, particularly the role played in it by information is underlined. It is argued that quantum mechanics becomes logically closed and contains no para- doxes if it is formulated as a theory of open systems with decoherence taken into account. If one insist on considering a completely closed system (the whole Uni- verse), the observer's consciousness has to be included in the theory explicitly. Such a theory is not motivated by physics, but may be interesting as a metaphys- ical theory clarifying the concept of consciousness. Contents 1 Introduction 152 2 Decoherence by entanglement with an environment 153 3 Restricted path integrals 155 4 Monitoring of an observable 158 5 Quantum monitoring and quantum Central Limiting Theorem161 6 Fundamental character of decoherence 163 7 The role of consciousness in quantum mechanics 166 8 Conclusion 170 151 152 Michael B. Mensky 1 Introduction It is honor for me to contribute to the volume in memory of my friend Michael Marinov, particularly because this gives a good opportunity to recall one of his early innovatory works which was not properly understood at the moment of its publication.