《自然》杂志载文谈物理学家泡利和心理学家荣格的友谊

武夷山

2024年4月19日出版的《自然》杂志发表了英国伦敦大学学院科学史与科学哲学名誉教授Arthur I. Miller的一篇文章，How the unlikely friendship of Pauli and Jung led to the discovery of CPT symmetry（泡利和荣格之间难以置信的友谊何以导致了CPT对称的发现，博主注：CPT指电荷共轭、宇称和时间反演三种对称）。

这篇文章中我最感兴趣的是这样几句话：“人们往往认为，物理学的发展要么来自基于早期理论的推导，要么完全来自对数据的研究，或是由于灵光闪现。其实真相处于中间的某处，包含各种要素，如竞争、灵感及爱、恨、嫉妒等情感，还有梦境，如泡利的情况”。

我将这篇文章附在本文的最后。

我2019年写过一篇关于泡利与荣格的交往的文章，这里重贴一遍：

当泡利遇上荣格

武夷山

（发表于《科技日报》2019年4月26日）

    1945年，奥地利物理学家沃尔夫冈·泡利因为提出“泡利不相容原理”而获得诺贝尔物理学奖。在提出了互补性概念的丹麦物理学家尼尔斯·玻尔的影响下，泡利认为，实在既是物质性的客体，也是形而上学的（超物质性的）客体。而事实上，他的实在观的形成还同他与瑞士心理学家卡尔·荣格的交往密切相关。

    泡利与荣格不仅有着长期的交往与合作，他们之间的友谊与学术交流还催生了同时性（synchronicity）概念的问世，将科学世界与精神世界连接到了一起。

  20世纪30年代初，泡利在思考β衰变中能量不守恒的问题。他在1930年底一封写给著名物理学家莉泽·迈特纳的信件中提出，可以用一个当时尚未观测到的、电中性的、质量不大于质子质量1%的假想粒子来解释β衰变的连续光谱。1932年，意大利物理学家费米将此粒子定名为中微子。也是在这个阶段，泡利的生活经历了一些变故，他感受到了深深的痛苦与精神危机，陷入心理绝境的他向当时也住在瑞士苏黎世附近的荣格求助。

    一开始，荣格为泡利做了400多个梦的梦境分析，再后来，他俩的讨论延伸到双方都有兴趣的其他主题。两人持续交往了20年以上，直到泡利去世。两人共同致力于通过物理学和心理学的双重视角来探讨实在的性质。他们认为，原子和自我有很好的类比关系：原子由原子核和绕核旋转的电子组成，自我由处于中心地位的有意识自我和周围的无意识自我组成。

    最初将泡利吸引到荣格身边的，是荣格关于象征和原型的研究。“原型”是德国天文学家开普勒很喜欢的一个概念，他相信世界是上帝创造的，而上帝创造世界绝不会胡来，而是按照一定的“原型”来创造的。泡利也十分喜欢这个概念，他在多篇文章和演讲中谈到，开普勒的炼金术理念和原型理念对开普勒的科学体系有着重要的影响。泡利还发现，物理学中有许多东西与炼金术理念和原型理念有可类比性。他还认识到，量子力学的问世，使人们更有必要将实在的不同侧面加以调和。

    受荣格的影响，泡利也很关心意义。荣格的全部工作都基于一个基本信念：“人无法忍受无意义的生活”。不过，泡利在这方面的表述非常谨慎，他说，虽然粒子物理学允许非因果形态的（注：在荣格心理学中，“非因果的”与“同时性的”是同义词，指意义上具有关联，而不是因果关联）观察，但对于“意义”这个概念毫无用处——也就是说，意义并非实在之基本功能，而只是人类观察者所施加的解释。

    荣格长泡利25岁，泡利事实上是他最优秀的学生之一。不过，泡利与荣格交往不久，就从科学角度对荣格理论的认识论侧面提出了批评，荣格接受了批评，进一步理清了自己的思路，尤其是明晰了“同时性”的概念。他们讨论学术问题的相关信件被收入一本题为《原子与原型：泡利/荣格往来书信选，1932—1958》的书，美国普林斯顿大学出版社2014年出版了该书的更新版。荣格对泡利的梦的分析也成为一本书的部分内容，该书的题目是《心理学与炼金术》，是荣格作品集的第12卷，1968年由普林斯顿大学出版社出版。

 Arthur I. Miller，How the unlikely friendship of Pauli and Jung led to the discovery of CPT symmetry

In 1931, the psychoanalyst Carl Jung took on an unusual patient, the brilliant young physicist, Wolfgang Pauli. Arthur I. Miller tells the story of their friendship, how they impacted each other’s work, and reflects on creativity.

“It was as if the wind had blown in from the lunatic asylum,” wrote Carl

Jung, of Wolfgang Pauli’s first visit. At the age of 31, when Pauli arrived at Jung’s doorstep, he had already published his work on his eponymous exclusion principle and was Herr Professor Doctor at the prestigious ETH Zürich. But he was also a disturbed human being. He was disliked by many physicists and had considered himself a failure because he could not solve certain scientific problems such as the anomalous Zeeman effect. He spent his nights frequenting the red light district of Zurich, drinking heavily and getting into fights.

Within a few years, the relationship between Jung and Pauli had become that of colleagues more than patient and analyst. Pauli had always been fascinated by alchemy, magic and myth, all of which were central to Jung’s psychology, although he was aware that colleagues, such as Niels Bohr and Werner Heisenberg, would disapprove of such topics. Jung wrote many papers and articles about his analysis of Pauli, but Pauli insisted that Jung not mention his name. Indeed, at Pauli’s funeral, his wife, Franca, relegated Jung to a seat at the back. She felt that Pauli’s friendship with Jung had degraded his image as a serious scientist.

Pauli was careful never to discuss his therapy with most of his colleagues, but privately, he attributed his work towards CPT symmetry to discussions and creativity sparked through his conversations with Jung.

Modern theories of creativity remain an open topic of research and many of Jung’s ideas have been superseded, yet the dialogue between the two provided the foundations for a great advance in physics.

Dreams and mirrors

Dreams are central to Jung’s analysis. In Jung’s psychology, the highest level of enlightenment is individuation, when the conscious and unconscious balance each other like reflections in a mirror. Pauli made himself a serious student of dreams, methodically writing up hundreds of his own dreams in detail. In his waking life, Pauli was perpetually preoccupied with the issue of symmetry, in both physics and psychology, which unsurprisingly seeped into his dreams. Jung wrote that an unnamed dreamer, who was actually Pauli, told him that he only felt himself to be in balance when he was sure that his “left [was] the mirror image of the right”.

In 1952, Pauli began to make in-depth mathematical investigations into symmetries in quantum physics, particularly mirror symmetry, or parity. “[B]etween 1952 and 1956 there was not actually anything going on in the world of physics to justify focusing on that particular subject,” he wrote to Jung. Rather, he was inspired to look into it by a dream he had, in which he was walking in the constellation Perseus and saw two stars of Algol. The two stars mirrored each other. Musing over the mathematics of mirror symmetry led him to explore two other reflective symmetries in his work: charge conjugation and time reversal. In early 1954 he put them together and discovered CPT symmetry: if you swap the charge, parity (left and right) and direction of time, of everything in the Universe it would be indistinguishable from the current one.

At first, Pauli thought he had discovered a very interesting new symmetry, but which had little relevance outside physics. But a few months later, he had a dream so curious that it stayed in his mind for years afterwards and convinced him that there were psychological factors involved that were sparking his interest in mirror symmetry.

In the dream he is with his ‘anima’, an idea from Jung’s psychology that represents the unconscious feminine side of a man. Pauli refers to his anima as the “dark woman”, a ghostly and faceless apparition-like

being. They are in a room in which experiments are being carried out involving reflections. Others in the room think the reflections are real, so there is no mirror symmetry. But Pauli and his anima know that they are just reflections. Nevertheless, they still worry that there is no symmetry between the objects and their reflections. From time to time his anima morphs into a distinctly Chinese woman whom he has seen in earlier dreams. Jung interpreted this Chinese woman as the holistic side of Pauli’s anima, in that Chinese philosophy (that both Jung and Pauli were interested in) always tends to reconcile opposites, like yin and yang.

Shattered dreams

Two years later, in 1956, two Chinese-American physicists, Tsung-Dao Lee and Chen-Ning Yang, sent Pauli an article in which they made the stunning argument that perhaps mirror symmetry might not always be conserved. Their study of the scientific literature had convinced them that there was very little experimental evidence for it and certain puzzling phenomena in elementary particle physics could only be eliminated if parity was not conserved in the so-called weak interactions which include radioactive decay. Pauli chuckled and put the article aside. Mirror symmetry was surely common sense — and it was also critical in Jung’s psychology. But other scientists took Lee and Yang’s proposal more seriously. The following year, a group of experimentalists at the National Bureau and Standards and Columbia University headed by Chien-Shiung Wu — a Chinese woman — carried out a very beautiful high precision experiment that proved beyond doubt that parity was indeed violated in the weak interactions.

Pauli was shaken by this unexpected discovery and its implications for his own work on symmetry. He also connected the events to Jung’s theory of synchronicity. According to Jung, synchronicity is the meaningful coincidence of psychic and physical states or events that have no causal relationship, such as between dreams and reality. A Chinese woman had played an important part in Pauli’s dreams, particularly those involving mirrors and reflections; and here was a Chinese woman carrying out the critical experiment that led to the downfall of parity. Pauli discussed his shock at the “Chinese revolution” in physics with Jung.

Finding deeper symmetry

After three months of intense thought, Pauli came to terms with the breaking of mirror symmetry by examining it through the lens of psychology: namely through realizing that mirror symmetry is an archetype, a key part of Jung’s theory of the psyche that he had introduced in 1919. According to Jung, archetypes are the organizing principles that enable us to construct knowledge through analysing incoming perceptions, and they reside in the mysterious shadow realm of the collective unconscious, common to all humankind. The archetype of mirror symmetry bubbled up through Pauli’s dreams and influenced his waking work on elementary particle physics.

Although mirror symmetry had been overturned, Pauli realized  that this was only a partial symmetry. The more profound, CPT, symmetry still held true: the astonishing assertion that our Universe cannot be distinguished from one in which all matter is replaced by antimatter, all positions reflected, and time runs backward. Before the downfall of parity Pauli realized that both physicists and psychologists had considered only “partial mirror images”. Full reflections and more profound symmetries can be obtained only by probing deeper into the psyche.

Reflections on creativity

Later dreams convinced Pauli that the “relationship between physics

and psychology is that of a mirror image”. Indeed, the cross-pollination

of ideas between the disciplines was appreciated by both men who sought a unification of physics and psychology. As Pauli wrote to a friend, “Every time I have talked to Mr Jung (about the synchronistic phenomenon and such) a certain spiritual fertilization takes place”. Jung for his part was intrigued by Pauli. He wrote that with Pauli he could enter the “no-man’s land between physics and the psychology of the unconscious […] the most fascinating yet the darkest hunting ground of our times”.

Pauli played a key role in bringing synchronicity, a pillar of Jung’s psychology, to fruition. His most important contribution was to draw Jung’s attention to Niels Bohr’s complementarity principle, which states that any description of a physical process cannot combine its developments in space–time with causality. Pauli pointed out to Jung that this insight of Bohr’s allowed him to relate the Western principle of cause and effect to the non-Western causality of synchronicity. The two proposed constructing a mandala in the form of a cross, though Pauli frequently criticized Jung’s suggestions, which were often couched in incorrect physics. In the end they settled on a mandala with causality and synchronicity forming the two ends of the horizontal arm, and energy conservation and a description in space–time at the two ends of the vertical arm. In this schema, causality and synchronicity are complementary but mutually exclusive, like the yin and yang. Jung’s classic paper on synchronicity was included in their co-authored book The Interpretation of Nature and the Psyche, along with a paper by Pauli who described the book itself as “a fateful ‘synchronicity’”.

People tend to think that discoveries in physics are generated either by deduction based on earlier theories, or entirely by studying data, or in a flash of inspiration. The truth lies somewhere in between and includes such elements as competition, inspiration, emotions such as love, hate and jealousy and, in Pauli’s case, dreams. Pauli’s thoughts on archetypes, dreams and symmetry are a wonderful example of Jung’s psychology in action and reflect elements that are part of modern theories of creativity such as unconscious thought. Most of our thinking is done unconsciously. Recalling his dream of the mirror image stars in Algol, and how this dream helped to precipitate his work on mirror symmetry, Pauli concluded that this “was a kind of synchronicity, because there are unconscious factors involved when you’re doing something”.