Paul Halpern is the author of the new book Synchronicity: The Epic Quest to Understand the Quantum Nature of Cause and Effect. His other books include The Quantum Labyrinth and Einstein's Dice and Schrödinger's Cat. He is professor of physics at the University of the Sciences in Philadelphia.
Q: How did you come up with the idea for your new book, Synchronicity?
A: In the course of my studies I have grown aware of two contradictory trends in the history of science.
One such movement, a development that began with the Enlightenment, has been to characterize the physical world through mechanisms involving direct chains of cause and effect that are eminently measurable.
For example, a strong wind might break off a tree branch enabling Earth’s gravity to draw it to the ground and crush a flower. Every step in that series might be observed in all its aspects and analyzed. Nothing happens remotely, except for the action of gravitation—which, as Einstein explained, also has intermediate stages.
But if one were to imagine a flower suddenly dying when the gardener that takes care of it has a bad dream, scientific thinkers would deem such a scenario as pure coincidence. Those who believed in such a connection—in the absence of direct physical proof—would be seen as unscientific and perhaps superstitious.
On the other hand, there has been a second trend in the world of physics itself, starting in the 1920s, to allow for the idea of remote, acausal linkage.
For example, in the phenomenon of quantum entanglement, two electrons might be prepared in a common state and widely separated. Then, measuring certain properties of one of the electrons immediately tells you about particular properties of the other electron—for instance, if the spin axis of one is pointed up, the other must be pointed down.
The history and prospects of the quest for theories that account for the delayed chains of causal connections and the instant synchronization of quantum entanglement seemed an interesting topic for a book.
Q: How was the book's title chosen, and what does it signify for you?
A: The esteemed Swiss psychoanalyst Carl G. Jung, a former disciple of Freud who broke with him and set out on his own path, coined the term “synchronicity” as a way of representing the concept of connections without a cause.
In doing so, he was influenced by Richard Wilhelm, who translated the I Ching from Chinese into German, as well as by Albert Einstein, who revolutionized the way physics addresses space and time.
I borrowed Jung’s term as the title of my book because I was interested in the way physics has addressed the concept of acausal connections, both real and purported, throughout the ages.
One focus of the book is the work of quantum physicist Wolfgang Pauli who was treated by Jung during a dark period of his life, revealing hundreds of his dreams during the therapeutic process, before collaborating with him. Pauli helped recast physics in a way that symmetry principles guide how particles behave, along with traditional causality.
Q: What would you say are some of the most common perceptions and misperceptions about quantum mechanics?
A: Quantum mechanics has inspired much debate. One general perception of it, that is absolutely correct, is that is it hard to visualize. Indeed, Newtonian physics is far more tangible, but, to our amazement, doesn’t operate directly in the realm of the subatomic world. Rather, indirect processes, involving intangible objects called “wave functions,” come into play.
A common misperception about quantum mechanics is that “anything can happen.” On the contrary, quantum mechanics has very rigid rules for certain transitions. Only within that context are there chance occurrences. Yet, over time, because of statistics, such chance happenings can lead to reliable outcomes.
For example, the fusion of protons in the Sun that helps heat up its core relies on a chance process called quantum tunnelling. Though that depends on chance crossings of an energy barrier, it is dependable enough that we expect to be able to bask in sunlight for billions more years, assuming our civilization is still around.
Q: What do you see looking ahead when it comes to the study of quantum mechanics?
A: These are exciting days for quantum measurement theories.
As I explain in my book, new experiments are being done to track quantum processes and try to unravel their inner workings for the first time. Meanwhile, signals conveying quantum information, through a process called quantum teleportation, are being sent out over farther and farther distances, for example to satellites.
Finally, quantum computers are being perfected to make use of the strange properties of entanglement in a way that lends far greater computational power to difficult calculations and cryptography than ordinary devices can muster.
Q: What are you working on now?
A: I have been working on several new blogposts for Medium to highlight and elucidate some of the aspects of my book.
My most recent piece was an interview with musician Max Born, one of the grandsons of quantum physicist Max Born. Einstein was good friends with the elder Born, and counseled him about the “dice-rolling God” in quantum mechanics. The younger Born has turned that idea into song lyrics in his tune “Quantum Blues.”
I’m also working on a piece about Wolfgang Pauli’s acerbic sense of humor.
Q: Anything else we should know?
A: During the course of my writing my standard poodle Kepler has been a steady companion and distraction. He likes to stick his head in front of my laptop and inform me when it is time to take breaks.
He is named after the scientist Johannes Kepler who plays an important role in my book in channeling his numerological interests into some of the first extensive scientific analyses: predicting how the planets move in their orbits. Pauli was very interested in Kepler’s work.
One time, when I took my dog on a walk, I passed by the same person twice, with about a 30-minute interval in between. The first time, I told him the name of my dog, which he recognized as belonging to the astronomer. The second time I saw him, he remarked, “I guess Kepler is taking you on a complete orbit!” I though that was a very clever thing to say.
--Interview with Deborah Kalb. Here's a previous Q&A with Paul Halpern.