In 1932, a brilliant young physicist at the Swiss Federal Institute of Technology Zurich was in trouble. Wolfgang Pauli, who seven years earlier had advanced quantum physics by formulating the Pauli exclusion principle, was recently divorced and suffered from depression. He drank excessively and was no stranger to red-light districts. When ­his father suggested a visit to the famous Zurich psychologist Carl Jung, Pauli acquiesced.

And so began a long relationship that is the subject of Arthur I. Miller’s Deciphering the Cosmic Number: The Strange Friendship of Wolfgang Pauli and Carl Jung. “Pauli was in a disastrous psychological situation,” says Miller, PhD ‘65, who studied physics at MIT and is professor emeritus at University College London. As Jung put it, “When [Pauli] came to consult me for the first time, he was in such a state of panic that not only he but I myself felt the wind blowing over from the lunatic asylum!”

More than 20 years ago, Miller came across a book the two men had coauthored. He knew Jung to be a great explorer of mysticism and alchemy–subjects that the hard-nosed, rationalist physicists of the early 20th century shied away from. But here was a giant of physics joining in. “In the book, Pauli discusses the 17th-century astronomer and mystic Johannes Kepler, and he delves into alchemy and mysticism with great passion,” says Miller. “Who was the real Pauli?”

In truth, it’s hard to say. Pauli stopped his analysis with Jung in 1934, and he kept the friendship that grew out of it under wraps. But the two men often dined in Jung’s mansion on Lake Zurich, talking long into the night about Pauli’s dreams; physics, psychology, and how they might be related; even ESP and UFOs. “Quantum mechanics does pretty well in establishing that we’re all made up of atoms and molecules, which are dead matter, so how is it that we are greater than the sum of our parts? This is what interested Pauli and Jung,” says Miller. “They never really answered the questions they raised, but they discussed things that scientists don’t usually discuss.”

For Jung, quantum physics became important in his consideration of synchronicity, or meaningful coincidences, which he came to believe formed a link between physics and psychology. Both men were intensely interested in whether there is a “cosmic number” that explains everything in the universe, and they devoted many discussions to candidates such as 3, 4, and 137. In their examination of what Miller says Pauli called “the shadow realm between mysticism and physics,” each took the other’s field as seriously as his own.

In 1945, Pauli received the Nobel Prize in physics for his discovery of the exclusion principle. He died in 1958, of pancreatic cancer, at 58–in room 137 at the Red Cross Hospital in Zurich.

“I never thought I’d be reading alchemy and mysticism and Eastern religion,” says Miller. “I’m still a rationalist concerning science. But there’s so much out there in the cosmos that we don’t understand. So maybe we should widen our minds.”