Customer Reviews

The Fabric of Reality: The Science of Parallel Universes and Its Implications (Allen Lane Science)

5 star:		(49)
4 star:		(17)
3 star:		(14)
2 star:		(15)
1 star:		(39)

 

 

Deutsch's presentation is fascinating, mind-expanding, challenging, provocative, and--at times--riveting. It is also infuriating, perplexing, reductive, and--at times--vague. (Please note: I am not convinced that the multiverse as Deutsch describes it exists, nor am I threatened by the possibility that it might. As a result, I do not mean to quarrel with--or support--the idea itself. Instead, I am reviewing Deutsch's book from the point of view of a lay reader.)

I do recommend this book to anyone interested in reading a summary of the pursuit of a "theory of everything" and a defense of the science of parallel universes. Deutsch's theory of everything depends on four theories: quantum (as espoused by Everett), epistemology (Popper), evolution (Dawkins), and computation (Turing). Even if one does not ultimately agree with Deutsch's ideas, his book offers some interesting thought experiments (the chapter on "time travel" is especially fun) and a concise overview of several scientific trends. In addition, his book provides a decent defense of why the theory of the multiverse should be considered a reasonable explanation for the interference results obtained the infamous two-slit experiment.

That said, I do think Deutsch's book contains many shortcomings. First, although the multiverse may be a valid explanation for interference phenomenon, Deutsch fails to convince that it is THE explanation. In one short paragraph, he dismisses David Bohm's theory of wave-particle duality. "Working out what Bohm's invisible wave will do requires the same computations as working out what trillions of shadow photons will do." One could easily reverse this sentence as a criticism of Everett and Deutsch: that the trillions of unseen photons requires the same computations as working out what Bohm's single invisible wave will do. Deutsch does not explain (in this book, anyway) why trillions of photons are simpler than one wave, and he does his readers a disservice by pretending that Bohm's work does not deserve a full refutation.

Second, and similarly, Deutsch dismisses with an even shorter paragraph the charge that his "theory of everything" is anthropocentric. (He pretty much admits it is, but tries--unconvincingly, to this reader--to turn it into an argument in his favor.) Third, his discussion of evolution (one of the four "equal" strands of his theory of everything) is a mere 25 pages and, unlike the rest of the book, is at times incomprehensible and seems completely indebted to Dawkins. (Not that there is anything wrong with Dawkins's work; rather, Deutsch just seems in over his head during this part of the book.) Fourth, he rejects Kuhn's belief in the rigidity of scientific paradigms (for example, the inability of thinkers in Galileo's time to accept the full implications of the Copernican system because they were so used to thinking of the world in Ptolemaic and Judeo-Christian terms), but then he describes a modern scientific establishment that refuses to accept the multiverse implications of quantum theory because they are rooted to the concept of a single universe. (Just because modern scientific discourse is more civil does not mean that Kuhn's argument is incorrect. Deutsch's opponents are still mocking him behind his back, in book reviews, and anonymously on this Web site. Or, even more effectively, they are ignoring him altogether.) And, finally, his discussion of Tipler's omega-point theory is hurried and unfortunately nebulous: at one point, Deutsch seems to be saying that knowledge in the universe will become omniscient and omnipresent--which is practically the same as saying that the universe will become itself.

Nevertheless, regardless of what you think of its implications, Deutsch's views deserve serious consideration and, as necessary, rebuttal--not mockery and scorn. In the same way that we read Lucretius even though we know him to be wrong (or, for that matter, Einstein because we believe he is mostly right), we should read Deutsch's work because he challenges the way we look at our world.

There are a lot of books that try to explain science to the layman and forward some new and grandiose worldview at the same time. Most of them do okay at the former, but fail miserably at the latter. This book does both, perhaps better than any book I've ever read (and I read a lot of science books). Deutsch identifies and explains the most important and interesting aspects of both quantum theory (his main topic) and the intimate relationships between it and the sciences of epistemology, computability, and evolution. The explanations are intuitive and easy to follow if you have any technical background at all, and sometimes even if you don't. Better yet, he convincingly synthesizes them into a truly compelling argument for a new (well, okay, not new but not yet widely accepted) view of reality on the deepest and widest possible scale. He steps onto a bit more shaky ground when he tries to bring in a "kitchen sink" of disciplines, some of which he doesn't seem to know nearly as much about as his native discipline (physics). Still, even the less convincing extensions to his basic idea are well considered and thought-provoking. And the basic idea itself--that zillions of not-quite-identical copies of our universe exist and are just as real and tangible as our own--is more than enough to make this book a phenomenal "mind-expanding" experience

The book was published in 1997, and a lot has happened since then. Yet the foundations retain their permanence, and David Deutsch's captivating writing is as fresh as ever. Despite the availability of newer books, for the layman/woman, now almost 10 years later, I would still rank this book at the top. There is a lot in the book; and yet, the ideas are presented in a clear and engaging way. The author is a pioneer, a giant in modern physics; he was and is a driving force in new discoveries in the subject. Yet he has his personal way of explaining physical reality. His view is not shared by all scientists, one should admit. However, there is agreement about the scientific conclusions. The first chapter in the book stresses *explanation*, our understanding of the reason for things. There are other views of science, e.g., instrumentalism: predicting the outcome of experiments.

The author's view on quantum theory is based his idea about parallel universes. While fascination, the reader should be aware that there are alternative theories for explaining quantum phenomena. An important concept in quantum theory and quantum computation is "decoherence", and it is explained (ch 9) in terms of different (parallel) universes. In ch 9 about quantum computers, it might have been only fair to mention that there are such other current views on decoherence; but this is a minor complaint.

Presentation: I love that each chapter concludes with a section on terminology and a summary.

As a subject theoretical computer science started with Alan Turing and John von Neumann in the 1940ties: Classical computation follows the model of Turing,-- strings of bits, i.e., 0s and 1s; and a mathematical model which is now called the Turing machine.

Instead of bits, why not two-level quantum systems, e.g., models built from electrons or photons? Such an analogues model for computation based on two-level quantum systems, and a quantum version of Turing's machine was suggested in the 1980ties by R.P. Feynman. The form it now has owes much to the author himself, David Deutsch. But it wasn't until Peter Shor's qubit-factoring algorithm in the late 1990ties (not covered in the book) that the subject really took off, and really caught the attention of the mainstream science community, and of the general public: The 'unbreakable' codes might be breakable after all !

That there is a polynomial factoring algorithm, as Shor showed, shook up the encryption community, for obvious reasons, and created headlines in the news. Ideas in the quantum realm, and not part of classical thinking, include superposition of (quantum) states, the EPR paradox (1935), and (quantum) coherence. Although these concepts are at the foundation of quantum theory, they make a drastic change in our whole theoretical framework of computation: Now one passes from the familiar classical notion of bit-registers to that of qubit-registers, and the laws of quantum mechanics take over. Mathematical physicists and computer scientists must revisit the old masters: Bohr, Einstein, Heisenberg, Pauli, and Dirac. In passing from logic gates to quantum gates (unitary matrices), the concept of switching-networks from traditional computer science now changes drastically. The changes introduce brand new scientific challenges, and new truly exciting opportunities. I believe that this book does justice to this, and that it is still a fascinating and thought provoking invitation to some of the most intriguing trends in modern physics.

This book is full of ideas and is written with exceptional clarity and power. Some of the ideas are controversial, and the author makes no secret of that, but they are surely thought-provoking and may well turn out to be right. As a physicist, I can add that clarity in this book is not achieved at the expense of logical shortcuts and gross oversimplifications, as it often happens in popular science. The intellectual and scientific level of the discussion is very high.

David Deutch's 'Fabric of Reality' marks the triumphant return of Natural Philosophy. The central aim of this book is to present the structure of our best theories (evolution, [Quantum] computer science and epistemology) in a way that clearly relates them to our understanding of reality, and then show how these structures are inextricably intertwined. I believe he is remarkably successful and displays a thorough understanding of the subject matter outside of his 'native' QM as those subjects relate to his 'Theory of Everything'. Speaking of which, he is also the first (that I know of) to come anywhere close to understanding what this TOE really IS (and will become). That is, our TOE is now, and at any point in the future or past, the core intertwining of these theoretical strucures he so elegantly exposes.

In order to appreciate this book, it is neccessary to understand the angle Deutch takes on the undertanding of science and the growth of knowledge. And this requires a bit of historical context.

In the early 20th century, the two infant sciences of quantum mechanics and computation theory had no observed connections. In turn, the counter-intuitive results of the quantum theory (as revealed over the next 100 years) led to a loss of confidence in our ability to understand reality (as expoused by such buzzwords as 'uncertainty'). This intellectual climate led many of our best scientists to ignore the importance of taking our best theories seriously. Instrumentalism and positivism flourished. Explaination and understanding where not considered fundamentally important. Everything was arbitrary and only utility mattered (in the sense that accurate prediction was thought to be the only useful thing to do with a theory). Consequently, it was not understood how knowledge grew, as understanding itself was seen as unimportant!

If any of Deutsch's four theoretical 'strands' could be called the seed of Deutch's synthesis, it would be Popper's epistemology. For it is this explainatory structure that provides the 'structure for the structure' that Deutch then fits the remaining strands into. Essentially, Popperian epistemology says that knowledge grows only through the process of trial and error, conjecture and refutation, not by some inductive process. And the key to formulating a conjecture that will survive the refutation process is understanding the explainatory structures of our best theories as they relate to the problem's domain. The creation of new knowledge requires the human capacities of innovation and creativity, specifically the mysterious weaving process whereby similarities between seemingly disparate phenomenon are spontaneously seen. This is how Deutch weaves an accurate (though tenative) description of reality. More importantly, this is how Deutch's reality says it must be [self consistency]. If Deustch's theory itself is true, then, it constitutes a growth of knowledge. The theory itself describes how this can happen.

I would guess that Deutch had his first glimpse of the woven threads when he figured out that computation theory, once thought to be purely an abstract construct, had to have a physical basis in reality. After all, computers are physical objects, subject to the laws of physics. Alan Turing's classical computation theory had many incompatibilities with classical physics that kept it in the realm of abstractions, but we now know classical phyics is false. This physical basis for computation turned out to have its roots in our newest, most fundamental (reductively speaking) physical theory, quantum mechanics. Combine this with the role of computation in evolution (genes 'rendering' environments), along with the role of our senses in representing our environment to our brains (virtual reality), and the growth of knowledge (rendering ideas) and you can see how computational processes are fundamental to Deutch's reality.

Deutch's contribtions to science and philosophy probably won't be appreciated until we have working, practical quantum computers. Only then, when his theories are what allow us to build our working technology will he be taken seriously. 'Fabric of Reality' provides us then with a prescient glimpse of what will eventually become our world view, describing the first great unification of our best theories.

When I ordered The Fabric of Reality, I was hoping I would receive a book something like Quantum Computing for Dummies. While this book does not explain the nuts-and-bolts of programming quantum computers, it is nevertheless an eminently practical guide for problem solving in general, and is curiously comforting in the process in that it rationally confirms our deepest intuitions held from childhood. It also reveals much about the `sociological' aspects of doing science, from the egalitarian mode of the symposia, to the political elitism of much of the rest of it. This book (while yet coy) does not ultimately shy away from the dirty-little-secrets of scientific methodology. I heartily endorse The Fabric of Reality as `a must read' for anyone embarking on a career of thinking.

Having read this book, I feel I am now prepared to ace my Philosophical Implications of Science class exams (but alas, I am fifteen years too late). Deutsch takes us from realms of pedestrian problem solving up the heights of the Eiffel tower where we survey the breadth of the terrain of scientific problem solving and we learn that the two modes are the same. All of the principal players that were there in my philosophical science class are here again in the Fabric of Reality, Karl Popper, Richard Feynman, Kurt Gödel, Thomas Kuhn, Niels Bohr, to name just a few. Deutsch explores every domain of explanation I can imagine, quantum mechanics, final cosmology, morality, esthetics, reasoning, all interwoven into one continuous tapestry. Yet this is not a new orthodoxy. Indeed, this is finally a scathing reputation of all orthodoxies (including by implication, postmodernism) unless progressivism be labeled orthodoxy.

Deutsch's style is professorial (i.e. often overbearing and repetitive--although he is self-effacing when relating his own contributions). There are plenty of rhetorical questions that probe the reader's understanding and reveal wider and deeper implications. Every chapter (except the last) ends with a glossary and a summary, which reinforces the entire tapestry and affirms Deutsch's commitment to the reader, that they be given every opportunity to understand the overarching argument.

The Fabric of Reality waxes passionately about embracing always the best available explanations in science. This made the book read like a preamble to the final chapter The Ends of the Universe which is a discussion of Frank J. Tipler's Omega Point Theory. Apparently the Omega Point Theory is still off limits to `serious' science. While it lacks the mathematical precision physics has come to expect from new theories, the omega point theory is nevertheless a bona fide theory with testable predictions the first of which has been verified, the mass of the top quark, the measurement of which was eminent, hence the necessity of Tipler publishing when he did. While dutifully introducing many caveats to Tipler's assertions (many of which caveats are dubious or wrong-such as, mass and energy are limiting on the omega point trajectory), Deutsch declares that the Omega Point Theory is the best available explanation of the end of the universe and that escalating imperatives, controversies, and delights should continue to engage people (subjectively) forever.

Me again - but I feel that I should add some points to my initial review given some of the reviews that have subsequently appeared.

Like one of the readers below, what irrititates me about some of the unfavourable reviews here is that they are trying to cast David Deutsch as some kind of mystic, who espouses quasi-religious views about multiple universes and that his book is somehow akin to notorious works like "Chariots of the Gods: Unsolved Mysteries of Past". This is very unfair. As the reader below notes, Deutsch is hardly some scientific lightweight. He is one of the pioneers of quantum information theory and has been one of the leading thinkers, if not the leading thinker, in that area. OK, you can argue that there are plenty of examples in history of leading scientists holding nutcase views. However, this is not the case here. The multiple universes interpretation of quantum mechanics is a serious attempt at coming to grips with the implications of quantum mechanics. It is not some whacked-out piece of junk science. What makes it science (and also more than an "interpretation") is that in the interpretation other universes interact weakly with our universe *and are therefore detectable*.

Even if you do not believe the interpretation, it is still a useful way of thinking about quantum mechanics and this way of thinking can lead and has led to new and deeper insights into quantum mechanics (witness Deutsch's work on quantum computing). In addition, because there is at present no widely accepted interpretation of quantum mechanics, it is important that the implications of each interpretation be fully explored. To dismiss the multiverse interpretation and to make Deutsch out to be some sort of quack is, I think, both wrong and arrogant (I am put in mind of the incredulous who similarly dismissed atoms and germs)....

Since 1997, the idea of parallel universes has consistently gained adherents and is now considered thoroughly mainstream in theoretical physics. Of course, not everyone is happy with this development, since parallel universes strike many people as weird, and they cannot (by definition) be observed directly. But then neither can black holes, time dilation at high speeds, curved space, quantum wavefronts or superposition and other once controversial but now well-accepted ideas. Wherever you see a discussion of the "anthropic principle" or the "fine tuning problem," the idea of a multiverse is logically implied. Furthermore, multiple universes are predicted by chaotic inflation theory, the laws of probability, the fine-tuning of the universe, and the "unreasonable effectiveness" of mathematics, in addition to quantum mechanics.

However, despite the somewhat misleading subtitle, this is not an effort to prove, once and for all, that parallel universes "really" exist. Nor is it a book about theoretical physics per se. Rather, it is something much more ambitious and self-consciously speculative: to lay out a (draft) Theory of Everything and explore its implications. It is, in other words, an attempt to draw all of human knowledge into a comprehensive, coherent whole--a project which strikes some of his critics as an act of hubris. But, there are very good reasons why such a Theory can and should be attempted.

Over the past 25 years, nearly all branches of science have been undergoing a quiet revolution as they incorporate chaos theory, non-linear dynamics, and other holistic, dynamic systems and other "process" approaches into their disciplines. This new mathematics is drawing such diverse fields as evolutionary theory, consciousness studies, quantum mechanics, and information theory toward a kind of convergence. The advent of modern computing, for example, is transforming mathematics into a kind of natural science. Quantum mechanics, which is an entirely mathematical representation of reality, has many convinced that progress in physics no longer depends on measurement and experiment, but on probing the mathematical side of reality through things like computer simulations and thought experiments. In other words, "traditional" reductionistic science seems to have come to the end of the analytical line, insofar as it is no longer possible to "go deeper" than the quantum level. The central insight of the present scientific revolution is that when it comes to dynamic systems, the whole is almost always greater than the sum of its parts; so, look to the bigger picture.

The importance of a Theory of Everything, and hence this book, is that it points to areas where big chunks of human knowledge can be dropped into place like parts of a puzzle. Drawing our knowledge into a unified system not only makes things more comprehensible overall, it points to fruitful areas of collaboration between and among what would otherwise be insular disciplines. For example, there has recently been some headway toward a theory of quantum gravity (which promises to reconcile quantum mechanics with the theory of general relativity) using computer simulations to explore the geometry of spacetime at the quantum level. As computers become more powerful, we may be able to crack the mystery of consciousness, which seems to be fundamentally computational as well. But, how does one program a massively parallel quantum computer where all possible answers to multi-variable equations exist in superposition? Well, it turns out, that such programs will be too complicated to be written by human programmers. Fortunately, the problem is mathematically identical to evolution, which can be accomplished *in silico* by simulating a population of mutating algorithms exploring what biologists call "fitness space."

When I first read this book I found it brilliant, mind-expanding and thoroughly enjoyable. So, I was both puzzled and chagrined to see 36 one-star reviews. When I looked at them closely, I found that only about six of them were by reviewers with more than one review: one was by a recent high school graduate who was disappointed that it wasn't a physics book; another was by a prolific reviewer of fiction who found the whole thing over here head; one by an old-school scientist who didn't find parallel universes conclusively "proven"; two were by people who had nothing good to say about anyone; and one by a Christian who didn't like Deutsch's "Darwinism."

The vast bulk of the remainder looked suspiciously similar. All were anonymous reviewers rousing themselves from obscurity to write a SINGLE one-star review denouncing Deutsch's entire book over some essentially minor detail. These struck me as quite unfair, especially if they were all written by the same person. Despite superficial differences in formatting, they all seemed to share the same peevish tone, the same stilted academic style, the same basic structure and substance of their "criticism"--which, after some quibble on some point or other, was that they considered parallel universes a huge load of bunk. Hence, they felt "disappointed," "unconvinced," and terribly wronged at Deutsch's "failure" to persuade them otherwise. Fortunately, Deutsch's choice of (Everett's) "many worlds" interpretation of quantum mechanics has been vindicated by recent history, and it is now the dominant interpretation. Indeed, if anyone doubts that parallel universes or the multiverse are well-accepted in theoretical physics, they need only browse Max Tegmark's website or the hundreds of interviews with physicists at PBS's Closer to Truth website.

Once you understand that Deutsch's Fabric of Reality is about a Theory of Everything; i.e., about the biggest possible picture of reality, and not the details of any of its tributary theories, one can easily forgive Deutsch for glossing over the controversies and alternative theories that would have been covered more in-depth in a book on theoretical physics per se. Here, I think, it helps to appreciate the book Deutsch actually wrote, rather than pitching a fit because it isn't the book you wanted it to be.

It takes a great deal of intellectual self-confidence to attempt to pull off a feat such as this. Some may perceive this as a kind of arrogance, especially if he seems to give your pet theory short shrift in the scheme of things. I don't see it that way. Deutsch is very explicit that his Theory of Everything is provisional and only meant to be illustrative of what such a theory might entail, and what it might imply for interdisciplinary collaboration. One expects it to undergo substantial revision as new information comes in and things fall into place. So, even if Deutsch's theory is wrong in some respect, he still succeeds, because he gives us a both a rough draft and a way of thinking about how to formulate a future Theory of Everything. I think Deutsch is brilliant, and I feel smarter just being in contact with a mind as keen as his.

According to an anecdote, someone asked Ernest Hemingway what personal or intellectual traits he thought a good writer should have. He supposedly responded, "A built-in, shock-proof crap detector." I see David Deutsch as having such an innate mechanism, at least in the field of scientific inquiry. The impression this amazing work has left on me is that he (Deutsch) has been capable of seeing through all of the clouds of confusion and nescience in science past and present, and with genuine comprehension constructed the most satisfactory model of the physicist's holy grail-the Theory of Everything. Though it is still a minority view among other physicists, the framework that embodies his ultimate patchwork is the multiverse. (infinite number of parallel universes) The multiverse has versimilitude also in philosophy, making certain philosophical ideas compatible with physics and spacetime, e.g. freewill, with enough fruitfulness that "it would be worth adopting even if there were no physical evidence for it at all." (pp.339) It has much reason to be upheld as currently the best model of reality to fit also observed physical phenomena. Not only has he studied the observed phenomena of the natural world to conjure up this central thesis, but he has studied the whole philosophy and very definition of science itself. Especially after reading chapter 4, I had a different vision of science, namely that it is not in search of objective facts, but more so the explanations behind these facts of reality. Thus we are unlikely to reach the "End of Science" that John Hoorgan's at-most-average book mused on since we cannot rely on inductivism, thus we can only expect a further evolution to science-not a final end. (pp.64: In science the object of the exercise is not to find a theory that will, or is likely to, be deemed true for ever; it is to find the best theory available now, and if pssible to improve on al lavailable theories. Pp.142: There is indeed no logiccally necessary connection between truth and explanatory power.))And alongside rejecting omniscience and inductivism, Deutsch rejects further as his tools common sense (for we have scientific theories to find the real truth that are more reliable, even IF counter-intuitive) instrumentalism (which is refuted on pp.4. pp.7: To say that prediction is the purpose of a scientific theory is to confuse means with ends.) positivism (..as logically follows from the fallacious instrumentalism and is false by its own criterion) holism, reductionism (we need to explain higher levels of life, thought, & computation), solipsism, and even its mathematical counterpart intuitionism. To avoid the "cold reductionism" of other scientists and their respective fields who seem to some narrow, inhuman, and pessimistic, Deutsch integrates physical reality on the multiverse basis of quantum mechanics, with its emergent fields of evolution, epistemology, and computation, into an emergent picture of the fabric reality understood by the four fundamental theories (strands) that explain it. They are presented through the works of Dawkins, Popper, Turing, Everett. (He gives one of the most satistfactory introductions to quantum mechanics I have ever read, though I warn that it is presented AS the many worlds interpretation, and does not fully introduce the convential interpreting) All four of the above mentioned researchers' works have been simultaneously accepted for use in practice and ignored as explanations of reality. One reason for this odd reaction is that each of the four theories has cold explanatory gaps, yet when taken together they bring clarity and visibility through the clouds of confusion and nescience in science past and present. We can move to even better theories only if we take these best existing ones seriously in explaining our universe.

"Listen; there's a hell of a good universe next door: let's go." - E. E. Cummings (1894-1962), US poet.

"The Fabric of Reality" presents the mind-bending multiple universe (multiverse) hypothesis that arises from the "wierdness" of quantum phenomena in a style that is as clear as may be possible. The philosophical ramifications of this view are profound, and leads the author towards a fantastic overall discussion of the nature of reality itself. As a cell biologist myself, the lucid exposition of issues such as perception, knowledge, evolution and computing have opened new intellectual vistas. This is not a book for the uninitiated. At a minimum, a cultural background in quantum physics, biology, epistomology and computing are required. Indeed, the flow of logic became obscure to this reader when the discussion went deep within my scientific blind spots. In this regard, I was fortunate to have read John Gibbon's "In Search of Schrodinger's Cat", and Timothy Ferris' recent book "The Whole Shebang" prior to tackling "The Fabric of Reality". David Deutsch clearly is a man of exceptional intellect. He is passionate about his ideas. It is here where he may be faulted in that his ardent advocacy for the multiverse hypothesis tends towards the polemic. I am sure that physicists will have much to say about Deutsch's ideas, and I can imagine that the discussions will be hot. Outside of his own field, Deutsch's ideas approach the fanciful, but are always thought provoking. Although the overall style is lucid, the text can be a bit wordy and repetitive. These reservations notwithstanding, this book may emerge as a classic in the field of the philosophy of science. David Deutsch clearly possesses a remarkable intellect.