Quantum Enigma : Physics Encounters Consciousness , by Bruce Rosenblum and Fred Kuttner -- Book Review

Book Review

Quantum Enigma : Physics Encounters Consciousness by Bruce Rosenblum and Fred Kuttner "takes the implications of the quantum theory to their almost impossible-to-believe logical conclusion." [Page 7]

It's a a fascinating presentation of the early 20th century discovery that forced scientists to become philosophers. The paradoxical character of what we consider real and material continues to challenge each generation that studies it.

Some readers may be drawn to what appear to be the exciting topics that television documentaries tend to mention, such as the cosmological topics -- black holes, dark energy, and the big bang [194-197]. Readers searching for life's meaning may be interested in the physicists' look at free will versus determinism [169-170] or the anthropic principle [199]. However, a reader who hasn't previously learned the basics will derive the most benefit by following the discussion of classical physics in chapters 4 and 5, and continuing to the point where the double-slit experiment is explained [41, 61]. There are more than one enigmatic question in the field, and the authors do say a few words about the others, including what Einstein dubbed "spooky action at a distance"; however, the authors concentrate mainly on the paradox that arose from pondering the double-slit experiment. It was this experiment that disclosed the ability of matter to be, in the words of some physicists, in two places at the same time, or, in the words of others, in neither of those two places.

About the Authors

Bruce Rosenblum is Professor of Physics and former Chairperson of the Physics Department at the University of California, Santa Cruz. He has also consulted extensively for government and industry on technical and policy issues. His research has moved from molecular physics to condensed matter physics and, after a foray into biophysics, has focused on fundamental issues in quantum mechanics.

After a career in industry that included two technology startups, and following a second career in academic administration, Fred Kuttner now devotes most of his time to teaching physics at the University of California, Santa Cruz. His research interests have centered on the low-temperature properties of solids and the thermal properties of magnets. For the last several years, Kuttner has worked on the foundations of quantum mechanics and the implications of the quantum theory.

- From the Publisher

To make things really interesting, this field says that you're not even permitted to doubt the conclusions:

"Quantum theory has been subject to challenging tests for eight decades. No prediction by the theory has ever been shown wrong. It is the most battle-tested theory in all of science -- it has no competitors. Nevertheless, if you take the implications of the theory seriously, you confront an enigma. The theory seems to tell us that the reality of the physical world depends on our observation of it. This is surely almost impossible to believe." [51-52]

In case the reader is unfamiliar with the enigma that torments the authors, it goes something like this:

The first fact: If you shoot something very small, say, an atom, at a region of a barrier which has two narrow and closely-spaced openings, the double-slit apparatus, then a certain pattern appears on a screen on the other side of the barrier. It's the kind of pattern that's produced when two waves are combined additively, indicating that the one particle-wave must have passed through both openings, not just one or the other.

The second fact: If, instead of two openings, you use two boxes capable of trapping an incoming particle, and later you look inside them, you always find that one box or the other, randomly, contains that particle, and the other is empty.

I will phrase this more generally. If you don't do anything to monitor the location of something, evidence later shows that it must have passed through two places at the same time. If you look to find out where it is, then it is always found in exactly one place and not the other.

There is no doubt that observation of the process finally established the result. But what is an observation? To some physicists, as soon as the particle interacts with anything else, say, the screen that it hits, then the second object has fulfilled the role of the observer. However, other physicists believe that it is relevant that, exercising "free will", you could have chosen to do one experiment, or you could have chosen to do the other. They conclude that only a "conscious" observer makes the location of the particle become definite. The authors write, "No matter which side of this argument you favor, there are physicists who'd agree with you." [122]

Here is the philosophical disaster. A large object is a collection of small particles, so whatever is true of the small must also be true of the large. Are we to believe that a stone, a mountain, or a whole planet, wasn't there at all until the moment when a conscious being observed it being there? That seems to be an assertion that mind creates matter.

Erwin Schrödinger tried to expose a fault in the latter interpretation by telling a parable about a cat in a box. Suppose the apparatus were set up so that an incoming atom would trigger it to kill the cat. Those who claim that the presence of the atom in one box or the other doesn't become a reality until the experimenter looks inside must also be saying that the cat is neither alive nor dead, or perhaps both, until the experimenter looks inside. It seems that the objectivity of reality is being doubted. Schrödinger cited this reductio as absurdum to demonstrate what he considered a fault in the Copenhagen interpretation.

In 1926 physicist Erwin Schrödinger developed an equation that was subsequently interpreted by Max Born as the probability distribution for "finding" a particle somewhere. This wave function is said to be collapsed when the particle finally has a definite location. Later, the Copenhagen interpretation of quantum mechanics started with the efforts of Niels Bohr [100], who is best known for developing the first model of an atom in which the electrons jump up and down among discrete energy levels. While some interpretations of QM refer to the probability distribution of the position of an object, the Copenhagen interpretation doesn't even refer to an object having existence until it is observed to be a some position. [103] This school of thought holds a pragmatic concept of truth [110] according to which, the authors sum up, "the role of science is to predict the results of observations, rather than to explore what's really going on." [122]

I felt that Rosenblum and Kuttner disposed of the more philosophically idealist interpretation, and provided a very good defense of objective reality, when they wrote [page 121]:

"For all practical purposes, any macroscopic object is constantly "observed." It can't be isolated; it's always in contact with, entangled with, the rest of the world. And that entanglement is observation!

"It is ridiculous to imagine that a cat could be isolated. Every macroscopic object anywhere near the cat observes the cat. The photons emitted by the warm walls of the box, for example. Take an extreme example: the moon! The moon's gravity, which pulls on the oceans to raise the tides, also pulls on the cat. That pull would be slightly different for a standing, alive cat than for a lying, dead cat. Since the cat pulls back on the moon, the path of the moon is slightly altered depending on the position of the cat. It is easy to calculate that in a tiny fraction of a millionth of a second the cat's wavefunction would be completely entangled with the moon's, and thus with the tides and thus with the rest of the world. This entanglement is an observation. It collapses the superposition state of the cat in essentially no time at all.

"Even looking back at the earliest stage of Schrödinger's story, you can see how absolutely meaningless it is. When an atom is sent into Schrödinger's boxes, its wavefunction becomes entangled with the enormously complex wavefunction of the macroscopic Geiger counter. The atom is therefore "observed" by the Geiger counter. Since something as big as a Geiger counter can't, for all practical purposes, be isolated from the rest of the world, the rest of the world observes the atom. Entanglement with the world constitutes observation, and the atom collapses into one box or the other as soon as its wavefunction enters the box pair and encounters the Geiger counter. And the cat is either dead or alive. Period!"

With this, the authors easily discredited the suggestion that macroscopics objects can be in the superposition state, and the suggestion that the human mind has anything to do with the subject. In their own words, the have shown us why "Schrödinger's cat story and the discussion of conscious observation are irrelevant and misleading." [121]

And yet the authors seem to bend over backwards to give the opposing view the opportunity to testify, occasionally allowing the other side to control the vocabulary. They write: "But keep in mind that whenever we refer to 'observation,' the question of consciousness lurks." [100] I wanted to yell at the authors for being so close to abdicating on the meaning of "observation", when they can so easily demonstrate why that the "question of consciousness" does not at all "lurk." On one page [115], the authors say more than once that an object is created by "our" observation. I feel like screaming at their use of "our", since it doesn't matter whether the detector of the particle is a human sense organ or an intervening speck of dust.

There have been scientists who have argued that, if an atom is in the superposition state, neither here nor there -- and if a Geiger counter is set to click only if it is here -- then the entire Geiger counter must be in the superposition state ... until a consciusness human being looks at it. John von Neumann took this position in 1932. [180]. Wigner argued that, if you put a person into the box with the Geiger counter, and that person has instructions to write a check mark on the pad if the Geiger counter clicks, then that check mark is neither written nor not written until a second person opens the box to look at the pad. [120] In the disposition of such claims, the authors are, IMHO, a bit too polite and too diplomatic. I should like to take such claimants aside and remind them of the meaning of the logical fallacy known as argumentum ad ignorantium, e.g., the assertion that ghosts must exist because you cannot prove that they don't exist. Rosenblum and Kuttner should get tougher in the disposition of that line of thought.

It's necessary to handle the species chauvinism of some followers of the Copenhagen interpretation, who assert that the "observer" capable of collaping the wave function must be a human being -- not the sacrificial cat nor any other species of animal. That absurd claim, which is the opposite of everything that is science, has been given plenty of undeserved press coverage for the past three-quarters of a century. The authors challenge the assertion in just one easy-to-overlook location [119-120].

"Wait a minute! Can't the cat observe whether or not the cyanide cork has been pulled, and therefore whether the atom has entered the box? Don't cats quality as observers and collapse wavefunctions? Well, if cats, what about mosquitos? Viruses? Geiger counters? How far down can we go?" [119-120]

In this reviewer's opinion, an experiment will eventually answer "How far down can we go?". Maybe we'll learn that a large molecule can undergo diffraction but a pea cannot. Not only will we find out how far, but also why. We're just waiting for science to answer that question. We don't know how many decades we will have to wait for the answer. This isn't some kind of signal for us to run around saying that objective reality doesn't exist.

If while praising the book it's only fair that I find one bad thing to say about it, then it would be this issue of emphasis. When large numbers of pages are allocated to explaining each point of view that is subsequently seen to be fallacious, and then the disposal of the fallacy occupies just a few sentences, I'm not sure that these relative weights are quite right.

Another compelling part of the book is Chapter 15, The Mystery of Consciousness [167-192]. We hear from numerous investigators, who disagree among themselves on basic principles.

David Chalmers investigated the "hard problem" of consicousness. He studies neural responses to stimuli, and suspects that quantum mechanics is related to consciousness [172] Chalmers wrote his book The Conciousness Mind in 1996.

Francis Crick, one of the discoverers of DNA, wrote the book The Astonishing Hypothesis : The Scientific Search for the Soul in 1994 [173-174]. Crick hopes to find an "awareness neuron". David Chalmers disagrees, asserting that consicousness cannot be entirely an emergent property of large numbers of neurons [174b]. According to chalmers, "... no mere account of physical process will tell us why experience arises." [175]

Daniel Dennett, among whose books is the 1991 Consciousness Explained , denies that there is a "hard problem" of consciousness, and attributes the effect to the brain's editing of information. [175]

Some of the workers named there are biologists. It disturbs some to see physics join in.

"We've entered emotional territory. Most physicists squirm when their discipline is associated with "soft" subjects such as consciousness. Some are even infuriated when Schrödinger's cat story is told. Stephen Hawking claims to "reach for my gun." [121]

I wonder whether there will be any practical consequences at all. Perhaps a new recipe for dessert has more utility. All we can discuss here is what reality and existence mean, what the mind and thought are. Is that all? If the philosophy bug has bitten you, you already know why you must read this book.

Book review by Mike Lepore for crimsonbird.com