Wolfgang Pauli was a brilliant, forthright physicist, who made his mark in many different fields. He was known from an early age as a wunderkind whose insights into general relativity, quantum physics, and other fields were phenomenal. His treatise on relativity, written at the age of 20, was a brilliant summary of Einstein’s masterwork.
By the time he was in his 20s, he was one of the most respected physicists in the world, offering advice to Bohr, Einstein, and others. Impressed with his independence of thinking, Einstein often sent him unified field theories and other proposals, bracing in return for Pauli’s inevitable criticism. Pauli’s development of the exclusion principle — no two electrons (or related particles called “fermions”) might occupy the same quantum state, proved instrumental to advances in quantum physics, and led to the concept of spin.
Similarly, his suggestion of a new, extremely light, neutral particle called the neutrino turned out right on the mark. His Nobel Prize in 1945 was expected and well-deserved. Discussing that achievement, Einstein acknowledged Pauli as a worthy successor. Hence, one of Pauli’s nicknames was ‘Zweistein,’ or ‘Einstein 2.0.’
There was a dark side of Pauli, however. In the famous Copenhagen comic production of Faust, Pauli was depicted as Mephistopheles, or the devil. Other physicists nicknamed him “The Scourge of God,” an epithet he embraced. His critiques of other physicists were often cutting and discouraging. Yet, as Einstein often admitted, Pauli would usually turn out to be right. Pauli was resolutely a theorist, not an experimentalist, as demonstrated by the legendary “Pauli effect” in which he would seem to disrupt labs by his mere presence.
During a particularly bleak time in Pauli’s life (a divorce around the same time as his mother’s suicide), he turned to psychotherapy. On the advice of his father, he sought out the esteemed Swiss psychotherapist Carl Jung, who lived and worked in Kusnacht, a suburb of Zürich.
Jung was extraordinarily original in his approach. Originally designated by Freud to be a successor in the psychoanalytic movement, he broke with his mentor in advocating the controversial notion of a collective unconscious, among other innovations. Through Einstein (with whom he had dinner when Einstein worked in Zürich), he came to be familiar with the marvels of modern physics, including the flexible nature of spacetime in relativity. By placing space and time in the same malleable framework, general relativity conceivably allows for connections that defy the forward direction of causality, such as hypothetical “closed timelike curves” that loop backward in time.
Quantum mechanics, another revolutionary branch of modern physics, posits acausal connections between particles in a shared quantum state — a situation dubbed by Erwin Schrödinger as “entanglement.” Jung’s own term for an “acausally connecting principle” was “synchronicity,” which he hoped would describe connections of the psyche as well as the material world.
Jung’s deep interest in trying to find a fusion of modern physics and psychology, blossomed further after he met Pauli. Pauli embraced Jung’s form of psychoanalysis — particularly dream interpretation — and became of his most significant patients. It was decades later, when Pauli returned to Zürich upon the end of World War II, that they had their most significant discussions about physics. By then, Pauli had become convinced that nature had underlying numerical patterns that called for interpretation. His obsessions meshed well with Jung’s concept of archetype — fundamental commonalities in a collective unconscious.
Although Pauli was acerbic and skeptical toward the theories of other physicists, including Einstein’s attempts at unification, he channeled considerable energy into offering advice to Jung about shaping a hybrid between the quantum and the mind. He made suggestions to enhance Jung’s theory of synchronicity. As he conveyed to Pauli in a famous diagram, Jung placed synchronicity on par with causality, and asserted that the former could explain coincidental phenomena that the latter could not.
While the physics community has remained skeptical of such a concept, which for Jung was grounded in parapsychology and pseudoscientific assertions of extrasensory perception, the notion of entanglement, remains a mysterious aspect of quantum physics. Indeed, entanglement is a well-established scientific phenomenon. Perhaps it is time to take a fresh look at the Pauli-Jung dialogue, focusing on only what is scientifically proven, and examine the implications of long-distance coordination of particle characteristics in, for example, quantum teleportation experiments.
Today Pauli is not as well-known as Einstein, and Jung is not as well-known as Freud. Yet each in their day commanded tremendous influence over the physics and psychology communities, respectively. While Einstein and Freud each adhered to their own kinds of rigid determinism, Pauli and Jung each realized that the flexibility of modern physics, and its inclusion of symmetry principles, called for new descriptions of nature beyond mechanistic causality. Synchronicity offers a means of characterizing such acausal connections and advancing toward a fuller accounting of the natural world.
Paul Halpern is a University of the Sciences physics professor and the author of sixteen popular science books, including Synchronicity: The Epic Quest to Understand the Quantum Nature of Cause and Effect.