【作者】 姜小慧；

【导师】 万小龙；

【作者基本信息】 华中科技大学 ， 科学技术哲学， 2010， 博士

【摘要】 1935年的EPR论战,引出了定域实在论与量子力学完备性之间的矛盾。1935年,薛定谔就把这一矛盾称为“EPR悖论”,随后这一说法分别被玻姆、贝尔等人采用。贝尔不等式提出至今已经有了许多相应的检验实验,这些实验被称为是对矛盾双方进行抉择的“判决性实验”。许多物理学家们希望借助这些判决性实验在定域实在论与量子力学完备性之间作出非此即彼的选择,希望实验结果能对一方是决定性地支持,对另一方是决定性地反驳。但是经过这么多年的努力,至今仍没有找到这种能够做出“最后判决”的实验。不过,在这探寻的过程中,却引出了非定域性,量子纠缠等问题,而这些问题正是量子技术发展的关键。EPR这一篇仅仅4页的论文,就像一把打开神秘宝藏的钥匙,引领着人们找到无数的智慧珍宝。总起来说,过去70多年对EPR悖论的研究,主要可以分为两种进路。一种是哲学的,一种是科学的。在1935玻尔发表同名论文回应EPR论文以后的十几年里,对EPR悖论的讨论逐渐上升到哲学争论的层面。这一方面是由于当时物理学实验技术的限制以及社会环境的变化,另一方面也是因为爱因斯坦等人对于因果性,客观实在等哲学论题的关注,尤其是玻尔充满哲学意味的互补原理,使EPR悖论披上了厚厚的哲学外衣。按照这一线索发展下去就是延续到今天的关注量子力学对因果性与实在观所造成的重大影响的哲学研究进路；另一进路是科学的,1951年玻姆将ERP原文中的思想实验简化以后,就为用真实实验检验EPR悖论提供了可能性。随后贝尔不等式以及实验技术的发展,逐渐恢复了EPR悖论科学论题的身份。在这两种思路的影响下,EPR悖论问题俨然成了一种“实验的形而上学”’。经过这么长时间,ERP悖论问题不管是在哲学形而上学方面的研究,还是科学实验方面的进展,都已经取得了大量的成绩。所以,如果我们再从上述两方面任一方面去研究EPR问题,都极有可能演变成对他人工作成果的简单重复,不仅是事倍功半,而且也无太多意义。不过,经过细致的分析考察,我们发现,关于EPR悖论,还有值得深入发掘之处,还有另外一条道路_科学哲学之路_可以选择。这个进路应该是前面两种进路的整合,它比形而上学的研究更具有实证性,比单纯的科学研究更具有思辨色彩,更能体现方法论在科学发展中的作用,更符合“实验的形而上学”精神。本文中我们将关注以下几个问题：关于科学理性与科学信仰。科学家的理性建立在实验数据之上,他们尊重实验,尊重数据,所以才有了能量子,才有了光量子。科学家的信仰是建立在其科学信念之上的,爱因斯坦相信经典力学的严格因果性,所以爱因斯坦信仰的是“斯宾诺莎的上帝”。而玻尔的信念是不迷信任何既定体系,时刻欢迎新的问题,新的观点,所以才有了哥本哈根诠释。关于判决性实验。在以往科学哲学界关于判决性实验的各种观点中,我们倾向于以下观点：判决性实验具有相对的判决效力。并且我们认为,判决效力相对性的根本原因在于作为基础的背景知识是相对可靠的、历史性的,在一定时代背景下被认为是可靠的背景知识,随着认识的逐步发展,很有可能就暴露出隐藏在其中的缺陷,虽然背景知识总是在历史过程中不断被修订,但永远不会达到绝对可靠性。那么建立在这样的背景知识之上的判决性实验也不能是绝对可靠的,所以一直以来被视为判决性实验的贝尔类型实验以及新型EPR悖论类型实验均不能作为EPR悖论问题的终极审判官。关于悖论。悖论从字面上讲,它意指某种与通常接受的观点相反的东西。“悖论可以定义为从明显可接受的前提凭借明显可接受的推理而导出的不可接受的结论”。悖论的根源在于其看上去合理的前提(背景知识)实际上是有缺陷的,那么要想解决EPR悖论,就必须找出前提中有缺陷的地方。又由于背景知识的相对可靠性,悖论的解决也是相对的。霍华德所提出的“定域非分离性”就是从背景知识中去寻找解决悖论的突破口的成功案例。关于思想实验与科学悖论在科学发展中的作用。思想实验在物理学史上尤其是近代物理学史上有着很重要的地位,许多伟大的思想都是通过思想实验而发现的,因而说思想实验是促进科学理论发现的重要方式,我们称之为“思想的铲子”；而科学悖论,则可以分为由具体理论或实际实验揭示出来的悖论,以及通过思想实验而得出的悖论,科学悖论的任务是对科学理论进行检验,揭示理论中所潜伏的深层矛盾,常常是元理论层面上的矛盾,所以我们把科学悖论称为“思想的显微镜”。有了这两种得力的工具,我们就可以在科学的进程中,既可以勇敢地进取又可以随时发现问题以便修正前进的方向。关于微观粒子的个体性。个体性问题在量子力学诞生以后变得更加复杂了。个体性问题从“宏观物体的个体性如何具有的?”发展成“微观粒子是否具有个体性?”。微观粒子(全同粒子)的不可识别性以及量子系统的不可分离性(自我同一性丧失)使得部分科学家与哲学家得出结论说,微观粒子是没有个体性的。我们的观点则有所不同,首先“不可识别”并不等于“不可区分”,前者只是认识论意义上的概念,而后者才是本体论意义上的,所以“不可识别”的微观粒子仍旧可以是“可区分的”。而“可区分性”是个体性的一个充分条件,我们将通过粒子的“基数可区分性”来论证其仍然是具有个体性的,起码是部分的个体性；然后我们将引申“相对可分离的整体性”到“相对可分离的个体性”,指出量子系统的不可分离性并不等同于绝对不可分离的那种整体性,微观粒子仍然保留着自我同一性,也就是说个体性并没有完全丧失,而只是弱化到一定程度,显示出与宏观物体不同的个体性。从而也就说明量子系统具有弱化了的爱因斯坦意义上的“定域实在性”,EPR悖论也就得以消解。关于狭义相对论与量子力学之间的协调。定域实在论与量子力学之间的对立,在更深层次上就意味着狭义相对论与量子力学这当代最伟大的两个研究纲领之间的对立,因为定域性实在论是狭义相对论的核心假说之一。对任何一方的放弃,即使是在情感上都是难以接受的,因此人们为了将二者协调起来消除EPR悖论付出了许多的努力,霍华德所提出的“定域的非分离性”就是最好的表率,而我们则从量子的“弱个体性”的新视角进行协调。一方面,量子纠缠与远程关联已经成为确凿的事实；另一方面,量子粒子的“实在性”并不因之丧失,相互作用仍然是定域的、非超距的。前者是量子力学家所断言的,后者则是爱因斯坦所希望的。因此,将量子力学与相对论二者协调起来,使它们“和平共存”是大有希望的。更多还原

【Abstract】 The EPR argument in 1935 elicited the contradiction between local realism and the completeness of quantum mechanics. Schrodinger considered this contradiction as "EPR paradox" which was later accepted by David Bohm and John Bell. Since Bell Inequality was proposed, there have been many corresponding experiments and tests, which were regarded as "crucial experiments" to the decision between two sides of the contradiction. Many physicists expected that a clear-cut decision could be made between local realism and the completeness of quantum mechanics in virtue of these experimental results, that is to say, the experimental results could decisively support one while reject the other. However, the attempts to make such "last crucial" experiments still failed with so many years’ efforts, Nevertheless, some problems like non-locality and quantum entanglement were produced in the process of pursuing for the critical experiments, and these problems were the key of developing quantum technology. The paper of EPR with just 4 pages, like a key to a mysterious treasure, had been leading people to find out innumerable wisdom treasures.Generally speaking, the studies to the EPR paradox in the last seventies years mainly have two approaches:one is philosophical and the other is scientific. In more than ten years after Niels Bohr published the same-name paper to respond the EPR paradox in 1935, the argument for the EPR paradox gradually ascended to the philosophical level from the scientific level. That is partly because of the restrictions of physical experimental technology and the change of social environment, and on the other hand, the attention paid to some philosophical thesis such as causality and objective reality by Albert Einstein, and particularly Bohr’s Complementary Principle with philosophical meaning gave EPR paradox much more philosophical impression. What followed from this route was the philosophical research approach which had continued to this day and focused on the important effects made on causality and reality by quantum mechanics. The other approach was scientific, and after Bohm simplified the thought experiment in EPR original paper in 1951, there was a possibility for employing true experiment to test EPR paradox. With the development of Bell Inequality and experimental technology, the identity of the scientific thesis about EPR paradox recovered. EPR paradox had become a kind of "experimental metaphysics" under the influence of these two approaches.Many accomplishments have been made about the study of EPR paradox both metaphysically and scientifically for such a long time. Therefore, if we keep on studying EPR paradox either metaphysically or scientifically, it will be probably just a simple repetition of others’works, which may be not only cost too much time but also of little significance. Nonetheless, with careful investigation, we found that there will be many things to do about EPR paradox, and we can have another approach to choose, namely, the approach of philosophy of science. This kind of approach should be the integration of the previous two approaches, and it is more positive than the metaphysical approach, and more philosophical than the pure scientific approach. As a result, it will indicate the role of methodology played in scientific development more apparently, and will be more according with the spirit of "experimental metaphysics". This thesis will be concerned with the following problems.The first problem is about scientific rationality and scientific belief. The rationality of scientists is based on experimental data. Because they respected experiments and data, they discovered energy quanta and light quantum. The belief of scientists is based on their scientific faith, for example, Einstein believes the strict causality of classical mechanics, so his belief is "Spinoza’s God", while Bohr’s belief is not enslaved to any given systems and welcoming new problems and new viewpoints in any time, so there is Copenhagen Interpretation.The second problem is about critical experiment. Among various viewpoints about crucial experiments in philosophy of science, we are inclined to support the following point of view:crucial experiment has relative crucial effect. Moreover, we think that the relativity of crucial effect lies in the relative reliability and historicality of background knowledge as foundation. The reliable background knowledge in some historic time will probably expose its hidden defects with the development of our knowledge. The background knowledge will never obtain absolute reliability, even though it is endlessly revised in the historical course. Consequently, the crucial experiments based on such background knowledge are not absolute reliable as well, and for that reason Bell typed experiments which have been taken as crucial experiments and new EPR paradox typed experiments are not referred to as the ultimate judge for EPR paradox.The third problem is about paradox. Literally, paradox means something contrary to the usual well-accepted point of view. "Paradox can be defined as unaccepted conclusion reliably deduced from the well-accepted premise." The root of paradox consists in that the seeming reasonable premise or background is flawed, so if we want to resolve the EPR paradox, we must find out something wrong with the premise. However, because of the relative reliability of background knowledge, the resolution of paradox is also relative." Local non-separability" proposed by Howard is a successful case of trying to solute paradox from background knowledge.The fourth problem is about the role played by thought experiments and scientific paradox in scientific development. Thought experiments have played an important role in history of physics, especially in the contemporary history of physics. Many great thoughts were discovered through thought experiments, which are important way of promoting the discovery of scientific theories and can be viewed as "the shovel of thoughts". Scientific paradox can be divided into ones revealed by specific theories or actual experiment and ones derived from thought experiments. It aims to examine scientific theories and reveal the deep paradoxes concealed in theories which are usually the contradiction in meta-theory level, so we look on scientific paradox as " the microscope of thought". With these two powerful instruments, we can fearlessly proceed and discover problems at any time in order to revise the direction in the course of science.The fifth problem is about the individuality of microscopic particles. The problem of individuality which evolved from "how macroscopic objects have individuality" to "whether microscopic particles have individuality or not", became more complicated after the naissance of quantum mechanics. The indiscernibility of microscopic particles (identical particles) and non-separability of quantum systems (the lost of self-identity) make some scientists and philosophers conclude that microscopic particles didn’t have individuality. But we have different points of view. First of all, "indiscernibility "which is a concept epistemologically is not identical with "indistinguishability" which is a concept ontologically, so "indiscernible" microscopic particles might be still "distinguishable". "Distinguishablity" is a sufficient condition of individuality, and we will argue that distinguishablity has individuality (at least partial individuality) by means of "cardinal distinguishablity". Then we extend "the relative separable holism" to "the relative separable individuality", and point out that non-separablity of quantum systems is not identical with the absolute non-separable holism, because microscopic particles still keep their self-identity. That is to say, individuality doesn’t totally lost and just weaken to some extent so that it indicates a kind of individuality different from macroscopic objects. Therefore, it could explain that quantum systems have weak "local realism" in Einstein’s sense, in which sense EPR paradox can be resolved.The last problem is about the coordination between special relativity and quantum mechanics. The contradiction between local realism and quantum mechanics in deep sense means the contradiction between special relativity and quantum mechanics which are contemporarily both the greatest research programs, because local realism is one of the core hypotheses of special relativity. Abandoning either one of them is unacceptable even emotionally, so people have done much efforts of coordinating them to eliminate EPR paradox. The’local non-separablity" proposed by Howard is a good example, which motivates us to coordinate them from the perspective of quantum’s " weak individuality". On one hand, quantum entanglement and long-range correlation have become real facts, and on the other hand, "locality" of quantum particles doesn’t lost, and interaction is still local and non=act-at-a-distance. The former is asserted by quantum physicists, while the latter is expected by Einstein. Therefore, coordinating quantum mechanics and relativity to make them "peacefully coexist" is of great possibility.更多还原