Like The Pontiff, I am always happy to receive an email from a publicist offering me a free book to review. In this case, the book was Quantum Enigma: Physics Encounters Consciousness by Bruce Rosenblum and Fred Kuttner, of UC Santa Cruz.
I have to admit, the title made me a little uneasy. There have been a great many very stupid things written about quantum mechanics and consciousness over the years, after all. It’s published by Oxford University Press, though, so I figured they can’t be total cranks, and hey, free book!
I’m happy to report that this book does not add to the tally of stupid things written about quantum mechanics and consciouness. Instead, it’s a very readable and accessible summary of the troubling role of conscious observers in quantum theory, from the origins of the theory in the early part of last century down to the present day. If anything, the authors are too cautious, going out of their way to avoid taking sides, and merely presenting the different issues and interpretations of quantum theory.
More detailed comments below the fold.
This is very much a popular-level treatment of the problem of observers in quantum mechanics– I don’t think there’s a single equation in the book, despite several mentions of Schroedinger’s equation and others. This is an admirable goal, and it shapes most of the book.
In order to explain the weirdness of quantum theory, you first need to establish a baseline of “normalcy,” explaining a bit of classical physics for contrast. Most popular books on quantum theory contain some discussion of classical physics, and for a physicist, these chpaters are often the hardest part about reading popular books on physics– they don’t tell you anything you don’t already know, and the umpteenth time you read about Newton’s Laws, it gets to be a bit of a slog. Happily, Rosenblum and Kuttner dispense of this quickly– Newton gets 16 pages, and “All The Rest of Classical Physics” a single 12-page chapter.
Actually, they do everything quickly– the entire book is just over 200 pages– so the traditional description of the historical development of quantum theory moves along just as briskly, to get to the key issue of measurement and observation in quantum mechanics (again, despite extensive discussion of wavefunctions and their meaning, they manage not to include any equations, which is fairly impressive). They also include a brief discussion of the importance of QM for modern technology, calling it the basis of one third of the modern economy. This is a nice touch, explicitly laying out why the theory is important, before diving headfirst into the weirdness.
Once they get to their main topic, the pace slows a bit, and they spend a full chapter outlining the Copenhagen Interpretation (which they equate with “Shut Up and Calculate”), and another on Schroedinger’s cat and superposition states. They present a nice outline of the Einstein-Podolsky-Rosen experiment, and a really excellent physical analogy to explain Bell’s Inequality, that I plan to copy the next time I lecture about those topics. They give brief discussions of no less than nine different interpretations of quantum mechanics, and how each deals with measurement and observation, and then close with chapters exploring the issues involved in the whole idea of “consciousness,” what role quantum mechanics might play in that, and consciousness in cosmology.
They resolutely avoid drawing any conclusions about any of this. They merely present the various interpretations and odd theories, as if all are on an equal footing. Their objectivity is amirable, but I can’t help thinking the book would’ve benefitted from a stronger stance in the final chapters.
Though they deal with some very strange and frequently misrepresented material, they do an admirable job of avoiding and even denouncing quackery. They have some harsh words for What the Bleep Do We Know?, and deny that quantum mechanics supports mysticism:
Quantum mechanics tell us strange things about our world, things that we do not fully comprehend. This strangeness has implications beyond what we generally consider physics. We might therefore be tolerant whennonphysicists incorporate quantum ideas into their own thinking– even if they do so with less than complete understanding, or even a bit incorrectly.
We are, however, disturbed, and sometimes embarrassed, by cavalier, perhaps intentional, misues of quantum ideas, as a basis for certain medical or psychological therapies (or investing schemes!), for examples. A touchstone test for such misuse is the presentation of these ideas with the implication that the notions promulgated are derived from quantum mechanics rather than merely suggested by it.
While they could be stronger in their condemnation of quantum abuse, it’s good to see a book on this topic that doesn’t veer off into total woo-woo mysticism.
Of course, any review is obliged to make a few negative comments, and there’s room for that. Some of the writing is a little uneven, with choppy little passages of short declarative sentences followed by other sections full of long and complex sentences with clauses galore. The overall effect is a bit jarring.
There are also three or four sections that are written in the form of imaginary dialogues. These desperately want to be Goedel, Escher, Bach, and, well, they’re not even close. The imaginary visit to “Neg Ahne Poc,” where quantum phenomena occur in the macroscopic world, is particularly clunky, at least to my ear. The authors seem to view this as the centerpiece of the book, and refer back to it frequently, which is a little unfortunate.
The oddest thing about the book, though, is that most of the figures (with the exception of some photographs of famous physicists, and a couple of cartoons) are hand-drawn. There’s a certain quirky charm to having the discussion illustrated by little stick figures and crude sketches of apparatus, but I’m not sure why they don’t have a single photograph of an interference pattern. The difference between particle and wave behavior comes up again and again, and every time, is illustrated by a little hand-drawn cartoon of dots on a screen. It’s not hard to find a good picture of real interference fringes, or even of single-particle interference data, so I’m slightly puzzled by this decision.
In fact, this brings me to what I consider the weakest part of the book, which is the sparse reference to experiment. Particualrly in the last couple of decades, there have been many beautiful and elegant experiments done to demonstrate the various phenomena discussed in the book, and they’re hardly mentioned here. Where important results have been confirmed by experiment, they usually mention the existence of experiments, but never present data or any detailed discussion of how the experiments were done.
I suspect that this is a conscious decision, in keeping with their desire to keep the book at a popular level, but to my mind, it weakens the book. Some of the experimental confirmations of quantum theory are so dramatic that they can easily impress non-experts, and I think the book would’ve beneftted from their inclusion. But then, I’m an experimentalist, and I would say that…
(Incidentally, I’ll sneak in a plug here for The Quantum Challenge by Greenstein and Zajonc, which has a strong focus on experiments. It’s not really a popular-level book, though, as it contains a fair number of equations (and, indeed, served as the textbook for my Quantum Optics class), but it’s an excellent presentation of the experimental evidence of quantum weirdness.)
On the whole, this is a very accessible and readable presentation of the issues involved in describing the role of the observer in quantum theory. The material presented is all on a sound theoretical basis, and it’s laid out in a way that should be comprehensible for the general reader. While it might’ve been a more exciting book had Rosenblum and Kuttner decided to advocate a particular position, their comprehensive and objective summary of the issues and interpretations involved should provide a valuable resource for any reader who would like to understand the real science behind the fuzzy area where quantum physics meets consciousness.