The God Equation

The God Equation: The Quest for a Theory of Everything
by Michio Kaku
Doubleday (April 6, 2021), 215 pages
Kindle edition $11.99, Amazon hardcover $13.99

I am always interested in books on physics, quantum mechanics, and cosmology, so in reading a review of this title I decided it was worth my time. The author is a working physicist who teaches graduate students, but who also had written several books for the general reader. This is his most recent.

The purpose of the book is to discuss whether a “theory of everything” is possible, something that so far has eluded scientists. Kaku starts by reviewing the history of physics, starting with Newton, and moving on to quantum mechanics. I guess I’ve read more books (or listened to more audiobooks) on the subject than I’ve given myself credit for, because I noticed at least a couple of places where Kaku glossed over things where he could easily have provided a complete explanation. For example, he somewhat simplifies the (in)famous Schrödinger’s cat thought experiment, when presenting it exactly the way Schrödinger did would have taken perhaps another half paragraph.

Kaku spends some space, appropriately, discussing the race for the atomic bomb during World War II. He describes how Werner Heisenberg was appointed to lead the German effort. Kaku says that the Germans under Heisenberg were well behind the Americans, who were pursuing their secret Manhattan Project at Los Alamos. However, other sources I have read state that Heisenberg knew the correct formula, but deliberately introduced subtle errors, too subtle for anyone but the sharpest physicist to notice, that were just sufficient to prevent the Germans from getting the bomb.

But back to the theory of everything. Kaku “has a dog in this fight,” as linguist John McWhorter likes to say, and Kaku admits it. He tells us he has been researching string theory since 1968 and believes that it offers the best candidate for a theory of everything.

Near the end of the book he also tells us that string theory continues to uncover new layers, and a final, definitive version of string theory has yet to emerge. Kaku hopes that a definitive version of string theory will provide us with a neat, mathematically complete theory of everything.

Somehow, though, as I finished the book I was left disappointed and unconvinced.