Tuesday, September 08, 2009

Stenger vs. Quantum Gods, Part One

I read Quantum Gods: Creation, Chaos, and the Search for Cosmic Consciousness, by Victor Stenger. Stenger is a physicist who is in the popular-book writing business with a focus on the science vs. religion debate. I found the book to be thought-provoking and worth reading, although I have a couple of substantial criticisms.

The motivation behind the book is a good one. Stenger’s most recent prior book (he has written quite a few) was God: The Failed Hypothesis -- an entry in the recent mini-boom of books by materialist-atheists criticizing traditional Judeo-Christian-Islamic religion. (I didn’t read this book having read Dawkins, Dennett and Harris in the genre). Quantum Gods is intended as a sequel which moves beyond traditional religion to criticize some newer and less traditional ideas about God and spirituality.

Stenger spends the first chapter looking at surveys on belief (including this Pew study), and notes they at least suggest that a substantial number of self-identified Christians have non-traditional ideas about God (in particular indicating beliefs more reminiscent of deism than theism). Also, he suspects that a significant portion of “unaffiliated” respondents have replaced traditional religion with various spiritual and/or paranormal beliefs (someone is buying lots of books by new age-type authors with these themes.)

With this as backdrop, Stenger explains that one strand which ties together some newer theistic/deistic ideas as well as the new age spiritual ones is their efforts to incorporate or accommodate modern physics (hence “quantum gods”). He identifies, then, two targets: the first, which he labels “quantum spirituality”, is the group of new age-type ideas which invoke quantum physics to support ideas about personal spiritual powers and/or cosmic consciousness; the second target, called “quantum theology”, is a set of attempts to accommodate God’s putative role as creator or intervening agent with modern science.

Before proceeding with more detail I need to mention one annoyance I had with the book: it felt somewhat padded to get to book-length. At 263 pages, about half (roughly the middle half) consists of encyclopedia entry-style sections on topics in the history of science. The content is unobjectionable, but this wouldn’t be the book you’d choose to read to learn about classical physics, relativity, or the history of quantum mechanics (QM) and the standard model of particle physics.

I thought the best part of the book were the late chapters criticizing “quantum theology” – i.e. some modern theological ideas about accommodating religion and science. I just wish he had a lengthier survey of these. A common objection to the work of the “new atheists” is to say that they haven’t grappled with more sophisticated modern theology but only criticize traditional beliefs (which are, of course, those held by the large majority of laypeople). Stenger has a good first effort to fill this gap, I thought. I will say a bit more about this section in a follow-up post. Below I will address Stenger’s criticism of new-agers and “quantum spirituality”, which I didn’t think was as effective.

Mind over Matter?

Let me quickly say that one of the reasons the chapters criticizing “quantum spirituality” aren’t as satisfying is not Stenger’s fault. Some of the ideas in books like those of Deepak Chopra and Gary Zukav, and movies like “What the Bleep Do We Know” just aren’t serious. Inspired by an apparent link between observation and the outcome of quantum measurements, a major claim of these folks is that quantum physics shows that human beings “create their own reality”: thus one can heal illnesses and become wealthy (or perhaps do some yogic flying) through the power of one’s mind. I personally think the details of QM could be implicated in the eventual scientific explanations of life, mind and freedom. However, to the extent that extrapolations from QM are used to portray humans as capable of paranormal powers, we cross into crackpot territory, and there’s not a lot more one can say (Stenger provides a section in Ch. 12 reviewing paranormal claims).

My main problem with Stenger’s discussion, though, is that his own opinion about the interpretation of quantum mechanics is highly idiosyncratic: he tries to hew as close as humanly possible to the worldview of classical materialism. As keen as he is to refute the quackery, he is as just as critical of the idea that the interpretation of QM might have any relevance to explaining the relation of mind to nature. He also is dismissive of the common notion that the ontology of QM or quantum field theory is suggestive of a more holistic cosmos than classical materialism. Here he is on less firm ground, in my opinion.

Saying No to Holism

With regard to holism, Stenger devotes a couple of sections discussing Fritjof Capra, one of the progenitors of the quantum new-age publishing genre with his book, The Tao of Physics (1975). In the book Capra stressed connections between QM and eastern philosophies, which he said both emphasize interconnectedness and process. Stenger points out that Capra was inspired by his work on a research program which was proposed as an alternative to quantum field theory called S-matrix/bootstrap theory. He points out that this program didn’t pan out, and this undercuts Capra. Stenger also has a brief discussion of quantum luminary David Bohm, who late in his career also espoused a holistic philosophy inspired by his work on the interpretation of QM (for instance in his book The Undivided Universe, written with Basil Hiley). Stenger notes the fact that Bohm’s “hidden variable” view is not widely embraced, and implies this undermines Bohm's philosophy.

It seems to me that most interpretations of QM and QFT, not just Capra's and Bohm's, can reasonably be taken to imply a more non-locally connected and hence holistic view of reality compared to the classical picture (what, if any, implications this has for the world beyond particle physics is a separate discussion). Prior to measurement, "particles" are spread out in space-time and systems demonstrate entanglement. The wave aspect of reality has a holistic element. However, it turns out Stenger doesn’t want to concede even something this modest.

Forget About Waves!

We learn more about Stenger’s own views in Chapters 12 and 13, where he discusses the interpretation of QM. He gives some brief sketches of Copenhagen, hidden-variables, and many-worlds interpretations. His own view, surprisingly, begins with a claim that there is no wave-particle duality; there are only particles. He has a section entitled “The Fictional Wave Function”. He says the description of the quantum state is an abstract mathematical entity. He spends a paragraph downplaying the Schrödinger representation of QM, preferring Heisenberg’s and Dirac’s formulations, which lack the wave function (he does remind the reader that they all give equivalent results).

So, if only particles exist, and no ontological status is given to the quantum state, how do we interpret experimental results? Discussing a single-electron double-slit experiment, Stenger’s idea, inspired by Feynman’s diagrams, is that the single particle, traveling backward and forward in time, can produce the interference pattern. I ask: how can it do this with no guidance from a wave? (Also interesting to me is that Stenger throughout the book is quick to dismiss anything that might imply violation of special relativity, but he’s OK with time-reversal). That’s the end of the discussion, so I can only infer that Stenger thinks QM can be successfully interpreted as a particle-only ontology with time-reversal. I’d never heard this view before and it isn’t defended at any length (it may be given more discussion in a previous book).

Can QM Explain Consciousness?

What about mind? Stenger does mention in passing that Von Neumann and Wigner suspected mind was involved in the phenomenon of quantum measurement. Beyond that he mentions the Penrose/Hameroff proposal for microtubule-based quantum coherence in the brain. He dismisses this with the standard reference to Max Tegmark’s 1999 paper calculating decoherence scales. I personally think Hameroff’s speculations are unlikely to be true, but recently it has been established that quantum coherence can be maintained and exploited by biological systems (see also here). While it still seems unlikely that anything as large as neuronal assemblies can maintain coherence, the science of tracing the role of quantum effects throughout biology is only getting started. I think it is quite plausible that distinctive features of life and mind may yet have at least a partial (non-trivial) quantum-mechanically-based explanation.

So, my main question for Stenger is this: why throw out the baby with the bathwater? We don’t live in a classical world, and we should continue to probe the implications of living in a quantum world wherever it takes us. Let’s not let the fact that New-age folks are making unsupported claims close our minds to the possibilities.

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