Book Review: “What is Real?” by Adam Becker
Reviewed by Travis Norsen
Adam Becker’s “What is Real?” [Basic Books, New York, 2018, 370 pages] provides a carefully-researched but non-technical and popularly-accessible overview of “the unfinished quest for the meaning of quantum physics.” The book’s early chapters sketch the historical development of quantum mechanics, explain the challenge of understanding the iconic double-slit experiment, discuss Schroedinger’s infamous cat, recount the legendary debates between Einstein and Bohr, and explore the dramatic interactions between physics and politics, culture, and world history during the second World War.
But there is something that sets Becker’s book apart from the dozens of other books that fit the above description: the author has not drunk the Copenhagen Kool-Aid. This is not, therefore, the kind of book the revels, gee-whiz style, in the impossibility of making rational sense of the micro-world. It does not serve up yet another stale retelling of Bohr’s supposed triumph over the doddering Einstein. And it does not imply that the point of Schroedinger’s cat is that, according to quantum mechanics, the cat is (whoa dude) both alive and dead. This is simply not that kind of pop quantum book.
Instead we are treated (in “Part I: A Tranquilizing Philosophy”) to an extremely serious and clear-headed explanation of the quantum measurement problem – which it was, of course, Schroedinger’s goal to articulate and dramatize with the cat. Regarding Einstein and Bohr, Becker has taken the time to actually understand what Bohr never quite managed, namely that Einstein’s fundamental concern with the orthodox interpretation was not about indeterminism or uncertainty, but rather the fact that the orthodox interpretation implied a kind of non-locality that seemed to make it incompatible with (Einstein’s own) relativity theory. Reversing the narrative structure of the standard account, then, Einstein and Schroedinger play here the heroes’ role, while Bohr and Heisenberg are depicted … less sympathetically.
Another thing that sets “What is Real?” apart from most pop quantum books is that it neither stops in the 1930s nor jumps ahead to the latest generation of (11-dimensional, multiverse) gee-whiz speculation. Instead, the heart of the book (“Part II: Quantum Dissidents”) tells the stories of several physicists who kept “the quest for the meaning of quantum physics” alive in the 1950s and 60s, when a combination of the Copenhagen tranquilizing philosophy and post-war pragmatism had made the broader physics community simply abandon the quest. The sketches here of the lives of David Bohm, Hugh Everett III, and John Stewart Bell are very beautifully crafted. Becker does a nice job of explaining the pilot-wave and many-worlds theories (of Bohm and Everett respectively) as candidate solutions to the measurement problem. And unlike so many commentators, Becker actually gets Bell’s theorem right: “Einstein had proven that quantum physics must choose between locality and completeness, but Bell’s … proof showed that the choice is actually between locality and correctness.”
The book’s third major section (“Part III: The Great Enterprise”) gives a somewhat more fast-paced account of progress in “the quest” during the last 30 or 40 years. Characters here include John Clauser, Dieter Zeh, Abner Shimony, David Albert, Alain Aspect, Nicolas Gisin, David Deutsch, Chris Dewdney, Bryce DeWitt, GianCarlo Ghirardi, and Philip Pearle. We learn about the various activities of this new generation of quantum dissidents as they work on developing novel theoretical concepts, honing and exploring the ideas of Bohm and Everett, developing a third candidate solution to the measurement problem, pushing forward on both theoretical and experimental fronts to connect Bell’s proof with empirical data, and generally continuing to fight bravely against the orthodox quantum philosophy’s “claim that it is somehow inappropriate or unscientific to ask what is going on in the quantum realm.”
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.
A second minor complaint is that, at a few points, Becker makes it sound as if the thing that’s really weird and difficult to comprehend about quantum mechanics is that it describes particles as not really particles at all, but instead as waves. But if it were the case that quantum mechanics (for example) described electrons as localized wave-like disturbances in a field, what valid objection could there be to this? None that I can think of. The truth, of course, is that (contrary to what many people, even many physicists, seem to believe) quantum mechanics does not describe electrons in this way. Instead of N wave-like disturbances in a field, the theory describes a system of N electrons as a single wave-like disturbance in an abstract, 3N-dimensional space whose connection to ordinary three-dimensional physical reality is, at best, completely obscure. Maybe one is simply not permitted to mention things like “configuration space” in a book searching for a wide popular audience, but I fear that sharp non-expert readers may get the impression that the quantum dissidents were worrying about a non-problem because Becker doesn’t convey the full depth of the orthodox theory’s failure to provide even a comprehensible candidate account of “What is real”.
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 nominal focus of Becker’s book is the quest to understand “What is real?” in the micro-physical realm described by quantum mechanics. It is worth noting here that, despite clearly taking the side of the quantum dissidents against the Copenhagen orthodoxy, Becker does not push any particular interpretational agenda. Instead, he (appropriately and refreshingly) maintains an even-handed and non-dogmatic attitude. This is well-captured by his closing summary of “the great enterprise”:
“…we physicists should learn the different interpretations available and keep them all in mind while working. Hold on to them loosely, not dogmatically, and keep a fresh perspective on the work we do. I’m not saying that interpretations of quantum physics are something that every physicist should work on, any more than every physicist should be working on any other specific open problem in physics, like quantum gravity…. But all physicists should be aware of the problem and passingly familiar with the field…. Pluralism about interpretations might be the right answer, pragmatically, while we face that challenge. Or if not pluralism, at least humility. Quantum physics is at least approximately correct. There is something real, out in the world, that somehow resembles the quantum. We just don’t know what that means yet. And it’s the job of physics to find out.”
This is a book that can help remind even the most passionately sectarian participants in debates about the interpretation of quantum mechanics that we are allies in the same basic quest.
The book’s core value, though, lies in the much-needed light it sheds on the question of “What is real?” – not in the micro-physics sense I mentioned above, but regarding the history and sociology of the last century’s most successful and important physics theory. Becker, in short, sets the record straight – exposing the myths and distorted narratives told by Bohr’s followers, and identifying the true heroes as the dissidents who sacrificed so much to maintain fealty to what physics was, is, and should be all about. Most of the history and perspective that Becker lays out can be found elsewhere – in Bell’s papers, in biographies of Bohm and Everett and Bell, in the books of Jim Cushing and Mara Beller, etc. But Becker has done a great service in putting this fascinating story together into a single easily-digestible volume that is gripping, authoritative … and true.
As I mentioned above, I think experts in quantum foundations will find value in this book. It should also be of considerable interest to physicists from other, “regular” sub-fields, and non-physicist scientists more generally. Maybe this will be the book that triggers the desperately-needed phase transition in which regular scientists realize that most of what they’ve been told about quantum physics is naked, unscientific nonsense? And finally, regular people – who are not professional scientists but who are intelligent, skeptical, and perhaps somewhat concerned about the corruption of science – will find, in Becker’s book, an inspiring story of how the scientific spirit can be kept alive (even in the face of deep corruption and even, when necessary, by a very small handful of individuals) by staying focused on that most scientific of all questions: “What is Real?” The book is, in that sense, quite timely in a way the author could not have anticipated during its writing.
I sincerely hope it gains an extremely wide readership and manages to have a powerful influence.