The three rebels make intriguing heroes in Mr. Becker’s informative and enjoyable book. Their stories illustrate how personality, prestige and prejudice can play a role in elevating or marginalizing ideas in physics, as in any other branch of academic life. Mr. Becker takes a frankly partisan view, and while he acknowledges technical problems on all sides of the debate, his reasonable desire for a coherent narrative somewhat elevates the claims of the dissidents against the mighty Bohr. At times Copenhagen almost seems like the heart of an evil empire ... History is written by the victors, and journalism is the first draft of history. Since the quantum contest is still being fought, we should perhaps consider What Is Real? to be journalism rather than history. That is in no way meant pejoratively: Adam Becker has written an excellent, accessible account of an intricate story. Whether he has chosen to wear the right uniform will be for future readers to judge.
Becker sides with the worriers. He leads us through an impressive account of the rise of competing interpretations, grounding them in the human stories, which are naturally messy and full of contingencies. He makes a convincing case that it’s wrong to imagine the Copenhagen interpretation as a single official or even coherent statement. It is, he suggests, a 'strange assemblage of claims.'
In addressing these questions Becker takes a historical approach, leading us through responses starting with that of Bohr, the de facto leader of a group of early quantum theorists including Heisenberg (discoverer of the uncertainty principle), Max Born and Pascual Jordan, who collectively formulated the influential 'Copenhagen interpretation' — though, strictly speaking, there isn’t a single unified view ... Becker’s intent is not to sway us to any one of the newer interpretations; rather he hopes to convince us that the Copenhagen interpretation has had too great an influence on physics for historically contingent reasons, including Bohr’s outsize charisma.
And yet, reality works. And this apparent contradiction is at the heart of Becker's book, which takes readers through all of these epic discoveries and disagreements, always with the subject's deepest questions (like the book's title) foremost in view ... Books like What Is Real? live or die by the companionability of the author, and in this case Becker is a perfect choice to make sense of it all (or at least whatever sense is possible). He smoothly, easily dramatizes the great debates and the outsized personalities of quantum physics and fits it all into an enthusiastic, readable narrative, and along the way he digresses wonderfully on a wide variety of scientific phenomena. About the creation of thermite, for instance, he first warns his readers not to try this particular creation themselves (just in case the possibility of self immolation wasn't warning enough) and then describes it with a nifty brevity.
I found the writing throughout the book to be clear and engaging, although some of the examples and analogies used to convey the occasionally slightly technical details are a little bit cutesy for my taste. This is probably to some extent unavoidable in a book that is attempting to explain the twisted science, history, and sociology of quantum mechanics to a mass market audience. But these couple of glitzy and deliberately silly explanations did, for me at least, slightly undermine the serious tone – appropriate for the extremely serious topic – that Becker otherwise manages to achieve, even while keeping the narrative accessible and highly engaging. This may, however, be the kind of complaint that only readers of The Quantum Times are likely to make; the intended audience of the book may instead appreciate the occasional light-hearted explanations ... My only other complaint about the book is really a compliment: it ended too soon. I would have enjoyed (at least) one more chapter to bring the narrative all the way up to the present day.
The book has a few minor shortcomings. Becker gives too much space to recent applications building on Bell’s research, and too little to new developments in the philosophy of science. Yet he, like cosmologist Sean Carroll in his 2016 The Big Picture, does make an explicit case for the importance of philosophy. That’s a key call, with influential scientists such as Neil deGrasse Tyson dismissing the discipline as a waste of time. What Is Real? is an argument for keeping an open mind. Becker reminds us that we need humility as we investigate the myriad interpretations and narratives that explain the same data.
Readers trace decades of experiments, alternative philosophies, and surprising drama in the physics boys’ club to three intriguing possibilities: 'Either nature is nonlocal in some way, or we live in branching multiple worlds despite appearances to the contrary'—or quantum physics is incomplete. With his crisp voice, Becker lucidly relates the complicated history of quantum foundations.
The author works diligently to introduce them to a lay audience. Readers must put in the effort, but those who persist will come away with a taste of a basic scientific issue that a century of controversy has yet to resolve. A useful introduction to the history of quantum theory for scientifically inclined readers.
