SYNCHRONICITY by Paul Halpern is a fascinating look at physics and quatum mechanics; specifically, about the connections between cause and effect in the physical and quantum realms of the universe. Written for a general audience, this book provides a sort of history of astronomy and physics from the ancient Greeks all the way up to Einstein and other modern physicists and cosmologists.

One of the interesting aspects of this run through the history of the physical sciences is how popular theories would hold the status of "true" science for sometimes centuries until someone was brave enough and thorough enough in their new theory to cause the scientific community to take their radical new ideas seriously. Because the speed of light is one of the most important physical constants known, a lot of information is shared on how the differing ideas on the properties of light and its ultimte speed are focused on. Only when instrumentation becmae specific and advanced enough were physicists able to truly establish the correct speed for the speed of light.

This book also surveys other important physical constants such as gravity as other ways of exploring how the cause/effect cyly works in nature. And them science led to the discovery of the possible existence of particles and energies that might be connected without any particular causes --- leading to the coining of the term "synchronicity" for physical connections with no apparent causes between them. A fascinating inquiry into how the cosmos and world works and what science may reveal to humanity in the not-too-distant future.

I... don't know what this book is about.

Well, okay, that's not entirely true. The blurb purports, "From Aristotle's Physics to quantum teleportation, learn about the scientific pursuit of instantaneous connections in this insightful examination of our world."

And I guess that's true?

But a lot of it seems like a meandering digression into the lives and times of all the characters involved. In fact, what it reads very much like is Just Another Pop-Sci Book Purporting to Get the Reader Up to Speed on All Things Quantum, but Never Actually Getting There.

I'm pretty sure I made it to 71% before the word "synchronicity" was used at all, and that was in the context of Carl Jung. And that would be fine, if the next six percent of this book weren't then a literal retelling and interpretation of Wolfgang Pauli's dreams. I shit you not.

This book is the opposite of "presented without context." This book is all context and no premise. This would have been a really awesome pamphlet. I understand that the history of physics is important to any discussion that touches on the quantum, but I genuinely feel that I would be better educated on the subject matter at hand if an editor had reached down from on high and stripped away 60% of this book. There is a loose thread linking the myriad vignettes presented within, one that purports to be about quantum cause and effect, but what it reads like is someone who very much wants to tell you their thesis, but forgetting to tell you what their thesis is, but being really excited about it regardless.

Every now and again, I have an itch to read a science book to learn more about the scientific concepts that I only touched on in school (I majored in finance and English, so I only ever scraped the surface of science classes). Having had one of those itches recently, I decided to give Synchronicity a try.

Synchronicity provides a fairly in-depth look into the evolution of physics across the ages, starting all the way back with the ancient Greek philosophers. The book discusses the gradual development of human understanding of the major forces at play in the universe—such as gravity and electromagnetism—and their relationship to the complex concept we call “light.”

The book touches on many of the contributions of the “big names” in physics throughout the generations, as well as some of the lesser-known people who contributed important discoveries and theories that were gradually folded into our modern understanding of physics. Galileo, Kepler, Pauli, Einstein, and many more are mentioned thorough the text, and the author takes the time to examine how some of their complicated personal lives influenced the outcomes of their professional work.

Overall, I thought the author thoroughly explored the main topic in a sufficiently organized manner and constructed a solid timeline that clearly shows exactly how drastically human understanding of physics has evolved and how that understanding has impacted the development of society. While I did find the text a little dense in places—for my taste, of course—I can’t deny that it’s a very well researched and well structured reference text that anyone with a serious interest in the history of physics should add to their bookshelf.

Rating: 3.5/5

I was pleasantly by this book. Although my background is in biology, I have always enjoyed the mysteries and intricacies of physics. This was a great read for everyone, including people like me who do not have such a deep understanding of the subject but are still interested in it. I will definitely recommend this book.

I always love to read a good science book! It was so good that at some point I though is going to be high tech and I was watching a film instead of reading something!

Like Carl Jung (apparently), I was fascinated by the basic concepts of quantum mechanics the first time they were introduced to me and, like Jung, I have dabbled in misinterpreting what the theory has to say about how I, and all of human consciousness, fit into this illusory world. Although I haven't read any of Jung's works (despite being intrigued by his concepts of universal archetypes, the shadow, and the collective unconscious whenever I come across them), I have also long been fascinated by (what I understand of) Jung's theory of synchronicity – in the sense that I don't really believe in it as an immutable force of nature, but can't shake the feeling that it operates in my own life. To be sure: I'm a dabbler, a magpie of ideas, and as Synchronicity appeared to relate scientifically to some of my more esoteric interests, I suspected it would be right in my wheelhouse. And it was. But it wasn't exactly what I was expecting.

Starting at the very dawn of recorded scientific theory, author Paul Halpern traces the history of thought on cause and effect; and in particular, how that concept relates to light and the evolution of thought as to whether its speed has a definite, and unbreakable, upper limit. I loved everything about this historical journey – and especially loved learning how, throughout the ages, rational scientists have been unwilling to give up their more irrational beliefs in the face of indisputably contradictory evidence – and even when the narrative arrives at relativity, collapsing wave functions, and quantum entanglement, Halpern's writing is clear and explanatory enough to have not gone over my head. Ending with modern quantum theory (and seemingly acausal connections that have nothing to do with the universe sending me messages), Synchronicity is a fascinating read, beginning to end; not what I expected from the publisher's blurb but right up my alley nonetheless.

Synchronicity is a non-fiction hard science book, by Professor Paul Halpern.


« Any sufficiently advanced technology is indistinguishable from magic. », Arthur C. Clarke

« Reality is non local », Bell’s theorem correlate.


When I picked Synchronicity, I thought I was going to read a treaty leaning toward proving the actual existence of this phenomenon. I am a firm believer in synchronicity, having experienced too much of it in my life to ignore it. I’m even under the feeling that I’m constantly riding a synchronicity wave.

I was mistaken. This book wasn’t what I expected at all. However, it turned out to be the best book on the history and principles of physics I’ve ever read during my 45 years on our Earth.

Synchronicity is, at its core, a densely packed book presenting the history of physics (but also of other related fields such as biology and astronomy) through the history of well known, and less known figures of import to the advances of science. The author presents them, articulate their discoveries, their relationships, and even gives us a window in their personal lives and history.

Paul Halpern covers everything, from the antique philosophers (our first scientists), to the wonders of current advances in quantum mechanics, with classical mechanics and relativity (of course) in between.

He does it in a precise way, going over advanced notions of each theory, but in such a manner that the book is accessible to anyone. And, this is no small feat.


Carl Jung is the first to have coined the term synchronicity. The search for meaningful patterns in coincidences. It’s no secret that Jung had a fondness for the supernatural, which ultimately led to his break with Freud. Both psychologists had met Einstein, but they didn’t agree on its teachings applied to their field.

In this book, the advent of quantum mechanics is clearly presented as an inflexion point. Albert Einstein, at first rebutted by those inferrings of « Spooky action at a distance » slowly changed his mind and participated in some great advances to quantum science.

« The balancing act between pure empiricism and mathematical abstraction [proves] tricky ». Some renegade scientists turn away from realism as they make « encounters with the pliable nature of reality ». « The firewall that science had carefully constructed in the late nineteenth century between the tangible and the mystical […] no longer seemed so solid », and, for some, the supernatural might no be so super after all.

That’s also when philosophy circles back and makes a crashing return into the field of science. And, everything got turned upside down. For some years, and still today, experimentalist have taken delight in observing events not explainable by currents theorists, such as entangled macro objects, or the reversal of the arrow of time.

It is interesting, then, to realize that some of the quantum physics principles, such as the duality nature of light (both a particle and a wave), were observed centuries or millennia before the term quantum had even been uttered. Never underestimate antique philosophers.

David Hume, a 18th century philosopher, wrote « Pure belief in causal connections stems from our impressions ». Was he already questioning the nature, or even the very existence of objective reality ?

To return to the experiment I alluded to above, backward causality seems to imply a non-linearity of time, or even question the existence of time itself other than someone we, as observers, would need to experience causality. If there is no time, if reality is non local and, as such, objective reality doesn’t exist... Those are questions we better not ponder too much.

As for synchronicity, it’s the glue guiding the story of the book. « Jung began to ponder the notion of non local influences » long before we truly observed them in experimental settings. But, « How to separate the real from the illusory, true patterns from meaningless coincidences ? »

Is synchronicity the natural tendency of our mind to find connections where there are none, or are there really patterns in which would then not really be coincidences anymore ?

The author doesn’t give us an answer in his conclusion, but he gives us all we need to form our own opinion. Including, cherry on the cake, an extensive bibliography that can make for weeks of fascinating reading.


* Paul Halpern, PhD, is a professor of physics at the University of Sciences of Philadelphia, and author of numerous popular science books. He also appeared on The Simpsons.

** All parts quoted in this review come from the actual book, except for the two initial ones.


Thanks to Perseus Books, Basic Books, and Netgalley for the ARC provided in exchange for this unbiased review.