Quantum Mechanics and Realism

Quantum mechanics is usually presented as a challenge to scientific realism, but I will argue that the details of quantum mechanics actually support realism. I will first present some basic quantum mechanical concepts and results, including the Einstein-Podolsky-Rosen (EPR) experiment and Bell's theorem, and do it in a way that everyone can understand. I will then use the physics to inform the philosophy, showing that quantum mechanics provides evidence to support epistemological realism.     

Quantum Mechanics and Computation

In quantum computation non classical features such as superposition states and entanglement are used to solve problems in new ways, impossible on classical digital computers.We illustrate by Deutsch algorithm how a quantum computer can use superposition states to outperform any classical computer. We comment on the view of a quantum computer as a massive parallel computer and recall Amdahls law for a classical parallel computer. We argue that the view on quantum computation as a massive parallel computation disregards the presence of entanglement in a general quantum computation and the non classical way in which parallel results are combined to obtain the final output.     

Fine-Tuning, Quantum Mechanics and Cosmological Artificial Selection

Jan Greben criticized fine-tuning by taking seriously the idea that “nature is quantum mechanical”. I argue that this quantum view is limited, and that fine-tuning is real, in the sense that our current physical models require fine-tuning. Second, I examine and clarify many difficult and fundamental issues raised by Rüdiger Vaas’ comments on Cosmological Artificial Selection.     

量子实在:从量子力学到量子通讯

1935年为论证量子力学的完备性提出的EPR悖论开启了量子信息思想火花。20世纪80年代,由本奈特和多依奇等人研究、倡导和推进引发了量子信息研究的爆发。作为用量子力学机制处理信息问题的一种技术手段,量子信息技术同时也是对量子力学所描述的量子实在的技术性证明。信息技术的广泛使用不仅改变了普通人的生活,同时也对学者们理解我们存在的世界提供了技术方法和深刻的思想思路。从历史上考察这一技术的发展过程,有利于我们对这一新生技术的理解。     

Quantum Mechanics and Operational Probability Theory

We discuss a generalization of the standard notion of probability space and show that the emerging framework, to be called operational probability theory, can be considered as underlying quantal theories. The proposed framework makes special reference to the convex structure of states and to a family of observables which is wider than the familiar set of random variables: it appears as an alternative to the known algebraic approach to quantum probability.     

Ungrounded Dispositions in Quantum Mechanics

General metaphysical arguments have been proposed in favour of the thesis that all dispositions have categorical bases (Armstrong; Prior, Pargetter, Jackson). These arguments have been countered by equally general arguments in support of ungrounded dispositions (Molnar, Mumford). I believe that this controversy cannot be settled purely on the level of abstract metaphysical considerations. Instead, I propose to look for ungrounded dispositions in specific physical theories, such as quantum mechanics. I explain why non-classical properties such as spin are best interpreted as irreducible dispositional properties, and I give reasons why even seemingly classical properties, for instance position or momentum, should receive a similar treatment when interpreted in the quantum realm. Contrary to the conventional wisdom, I argue that quantum dispositions should not be limited to probabilistic dispositions (propensities) by showing reasons why even possession of well-defined values of parameters should qualify as a dispositional property. I finally discuss the issue of the actuality of quantum dispositions, arguing that it may be justified to treat them as potentialities whose being has a lesser degree of reality than that of classical categorical properties, due to the incompatibility relations between non-commuting observables.     

Quantum Mechanics and other Fields of Science

In recent times, a particular attention has been devoted to thesignificance of Quantum Theory for other disciplines. The articlescollected in this issue discuss some interesting cases,characterized by an interaction between Quantum Theory andother fields. Some basic notrons of the mathematical formalismof the theory are here summarized.     

Quantum Mechanics in a New Light

Although the present paper looks upon the formal apparatus of quantum mechanics as a calculus of correlations, it goes beyond a purely operationalist interpretation. Having established the consistency of the correlations with the existence of their correlata (measurement outcomes), and having justified the distinction between a domain in which outcome-indicating events occur and a domain whose properties only exist if their existence is indicated by such events, it explains the difference between the two domains as essentially the difference between the manifested world and its manifestation. A single, intrinsically undifferentiated Being manifests the macroworld by entering into reflexive spatial relations. This atemporal process implies a new kind of causality and sheds new light on the mysterious nonlocality of quantum mechanics. Unlike other realist interpretations, which proceed from an evolving-states formulation, the present interpretation proceeds from Feynman’s formulation of the theory, and it introduces a new interpretive principle, replacing the collapse postulate and the eigenvalue–eigenstate link of evolving-states formulations. Applied to alternatives involving distinctions between regions of space, this principle implies that the spatiotemporal differentiation of the physical world is incomplete. Applied to alternatives involving distinctions between things, it warrants the claim that, intrinsically, all fundamental particles are identical in the strong sense of numerical identical. They are the aforementioned intrinsically undifferentiated Being, which manifests the macroworld by entering into reflexive spatial relations.     

量子力学解释新的发展趋势及其问题

测量问题一直都是量子力学的核心问题,更是量子力学解释得以发展的根基。文章对量子力学中围绕测量问题而产生的几种解释思路进行了分析,对三种新的主流解释进行了说明,另外还对当下最流行的量子力学解释——埃弗雷特解释及其核心问题给出了解答,并对其成为新正统解释的可能性给出分析。     

因果性、直观性、个体性与量子力学——试析保罗·福曼关于魏玛文化与量子力学发展之关系

量子力学具有许多经典力学所没有的特征——比如非因果性、非直观性、非个体性等，也由于这些特征引起人们的极大兴趣及广泛讨论。然而，这些特征在多大程度上是理论本身所具有的或是人们所希望赋予的却很少有人注意到。美国当代著名科学史家及社会学家保罗·福曼(Paul Forman)从科学社会学的角度对此作了深入的分析并提出量子力学的发祥地——德国魏玛文化对理论的表述特征产生过重要影响等独到见解。本文拟对福曼的观点进行介招和分析。     

Embedding Quantum Mechanics into a Broader Noncontextual Theory

Scholars concerned with the foundations of quantum mechanics (QM) usually think that contextuality (hence nonobjectivity of physical properties, which implies numerous problems and paradoxes) is an unavoidable feature of QM which directly follows from the mathematical apparatus of QM. Based on some previous papers on this issue, we criticize this view and supply a new informal presentation of the extended semantic realism (ESR) model which embodies the formalism of QM into a broader mathematical formalism and reinterprets quantum probabilities as conditional on detection rather than absolute. Because of this reinterpretation a hidden variables theory can be constructed which justifies the assumptions introduced in the ESR model and proves its objectivity. When applied to special cases the ESR model settles long-standing conflicts (it reconciles Bell’s inequalities with QM), provides a general framework in which previous results obtained by other authors (as local interpretations of the GHZ experiment) are recovered and explained, and supports an interpretation of quantum logic which avoids the introduction of the problematic notion of quantum truth.     

非线性系统中微观粒子的特性和非线性量子力学

经过20多年的艰苦研究,最近几年里作者与合作者完成了《非线性量子力学理论》(1994年)、《孤子物理学》(2003年)和英文专著QuantumMechanics inNonlinearSystems(2005年)。在这三本专著特别是英文专著中,作者建立了一门新的学科———非线性量子力学,详细而全面系统深入地描述了线性量子力学(LQM)的困难,建立非线性量子力学(NLQM)的必要性和重要性,它的物理理论、实验基础和数学基础,所提出的NLQM的基本原理和理论及该理论的特点,由该理论给出的微观粒子的波粒双重性和其它特性及产生这些特性的非线性相互作用的类型及产生的机理,如何…     

量子测量问题新解

量子测量问题悬而未决已近一个世纪,而目前学界日益倾向于将之归结为两个必须由量子理论回答的问题,即"明确结果问题"和"优先基矢问题"。21世纪初,John H.Conway、Simon Kochen等人提出了"自由意志定理",主张粒子具有自由意志。这意味着粒子具有自主选择与知觉的能力。粒子的知觉能力与自由意志均进一步地与能量这一基本物理量紧密相连,从而形成两条基本原理:"知觉-能量原理"和"意志-能量原理"。凭借这两条基本原理,"明确结果问题"和"优先基矢问题"便可得以解决,一条新颖的量子力学诠释进路也因此而呈现出来。     

量子力学多世界解释中的概率问题

多世界解释在量子概率问题中占有重要地位。面对对多世界宇宙图景和概率概念在不相容性、证据有效性、决定论等方面相矛盾的批判,多世界解释提出了一系列辩护。然而这些辩护并不牢靠,因为其策略回避了多世界解释最根本的问题,即概率不守恒,从而导致辩护不能彻底,只能转移、隐藏问题,并催生出多世界解释的其它困难。舍弃对多世界物理实在性的预设,回归原初的相对态解释,则能够解决这一根本问题,并更好的实现这一创造性构造的启发功能。     

Symmetry,Potentiality and Reversibility

This short comment confirms Longo’s observation about the importance of symmetries for understanding space and time, but raises the additional issue of the transition from reversible to irreversible transformations.     

量子多世界理论的范式转换

多世界理论的范式结构是在相对态解释的基础上,基于不同的理解和视角发展出的包括多世界解释、多心灵解释、多历史解释在内的多种解释范式的集合。整体来说这些解释范式都是对形式体系的一种理解,缺乏经验上和常识上的验证,完全是在理性推理和逻辑演算的基础上加入了个人的理解而做出的论证。因此,要深入理解多世界解释的内涵和本质,需要从整体上对各个解释的范式结构及其转换进行全面的理解和透视。本文将对多世界理论的诸多范式结构转换进行系统的梳理和评述。     

范·弗拉森的量子力学解释理论

范·弗拉森的量子力学解释理论既是他的量子力学哲学的核心，也是他的建构经验论的科学思想基础。本文主要从量子力学的一般解释理论、量子力学测量问题、测量的模态解释的主要思想、模态解释的意义等四个层次较深入浅出地介绍范·弗拉森的量子力学解释理论。     

Quantum Superpositions and the Representation of Physical Reality Beyond Measurement Outcomes and Mathematical Structures

In this paper we intend to discuss the importance of providing a physical representation of quantum superpositions which goes beyond the mere reference to mathematical structures and measurement outcomes. This proposal goes in the opposite direction to the project present in orthodox contemporary philosophy of physics which attempts to “bridge the gap” between the quantum formalism and common sense “classical reality”—precluding, right from the start, the possibility of interpreting quantum superpositions through non-classical notions. We will argue that in order to restate the problem of interpretation of quantum mechanics in truly ontological terms we require a radical revision of the problems and definitions addressed within the orthodox literature. On the one hand, we will discuss the need of providing a formal redefinition of superpositions which captures explicitly their contextual character. On the other hand, we will attempt to replace the focus on the measurement problem, which concentrates on the justification of measurement outcomes from “weird” superposed states, and introduce the superposition problem which focuses instead on the conceptual representation of superpositions themselves. In this respect, after presenting three necessary conditions for objective physical representation, we will provide arguments which show why the classical (actualist) representation of physics faces severe difficulties to solve the superposition problem. Finally, we will also argue that, if we are willing to abandon the (metaphysical) presupposition according to which ‘Actuality = Reality’, then there is plenty of room to construct a conceptual representation for quantum superpositions.     

因果性、魏玛文化、与量子力学--析保罗·福曼的科学社会史思想

美国当代著名科学史与科学社会学家保罗·福曼(Paul Forman)曾于20世纪60年代末就魏玛德国物理学家为何易于接受量子力学的非因果性特征做了深入的社会文化分析,指出魏玛文化中的非理性主义思想对促使物理学家思想转变起到重要推动作用等看法,在西方科学史界引起普遍关注和争议.本文分析福曼研究的时代背景及研究方法,指出福曼的工作不仅在20世纪70年代西方科学史研究从内史向外史的转向中起到重要的推动作用,而且也为70年代诞生于西欧的科学知识社会学提供了一个微观层次上的经典范例.     

量子力学的本体论解释 --戴维@玻姆观点简介

本文阐述了量子力学的实质,介绍了玻姆对量子力学的本体论解释,高度评价共科学－哲学思想的重大意义。