The Fabric of Reality: Towards a Theory of Everything

I have read innumerable books and science magazine articles on quantum theory, relativity, astrophysics, astrononmy, string theory, etc, as well as a great deal of more generally related science. I am not a trained scientist, simple a well informed non-specialist with an interest in these areas, and I would have to say that this is the best written book of its type I have come across. It deals with extremely deep concepts across an enormous range of different but related areas of study, and I found myself at times almost shocked at the superb skill with which the author is able to deliver new concepts and arguments so cleanly and simply. The chapter that deals with quantum theory and the many-worlds hypothesis alone stands out as a masterpiece of elegance and simplicity when compared with many other works that attempt to deal with this issue. Rather than delighting and wallowing in the apparent paradoxes that quantum theory implies for the macroscopic world (as so many authors do), Deutsch simply points out that irrespective of our inability to understand and resolve those paradoxes, the conclusions at least are clear and unarguable, and this is where he starts the real work of philosophical integration that is the books theme. The rate at which new ideas in this book are delivered can leave one stunned at times, and I must recommend this book without any hesitation at all.

If you're more used to theoretical science books with recommendations from Yoga magazine and popular self-help gurus then this will be the hate filled heresy of a madman.So if you still cling to the antiquated,consciousness affects external phenomena of the Copenhagen Interpretation then you should look away now,but it would be better if you didn't. The authors views of the "shadow multiverse" theory are put forth and then vigorously defended by way of epistemology,computational science and evolution.Along the way we get to resolve the Grandfather Paradox in regards of time travel,marvel at the theoretical computational creativity of Alan Turing and ponder on the thought that all we perceive maybe an artifact of an advanced future civilisations'universal virtual reality generator.Obviously with these type of subject matters it is not going to be an easy ride,but although I found the going tough in places,especially the chapters on epistemology and the nature of mathematics,I found that it was not necessary to understand all the intricacies to get the message that was being conveyed. The only negative criticism I have is that it felt like parts of it where written on the defensive and the author was concerning himself with defending the ideas philosophically in light of the fact that proof was a little too inconclusive to convince adherents of oppositional theories. To sum up this is not a light romp through contemporary theoretical physics but if you are familiar with popular science and some basic philosophy then it can expand your knowledge of the possible that may become probable.

This book was written as a popular science book to be compared with, and perhaps inspired by, well known favourites such as "The Emperor's new Mind", "The Selfish Gene" and "Godel, Escher, Bach" and, given that it was published in 1997, I was surprised I hadn't come across it before. The author, David Deutsch, is well known for his influential papers on Quantum Computation. Here, he tackles a very broad canvas which includes quantum mechanics, quantum computation, virtual reality, time travel, the foundations of mathematics, the emergence of life and the theory of evolution. Deutsch takes issue with reductionist views of science and proposes that a "Theory of Everything" must encompass all these aspects of science, as expressed in four major strands: quantum physics, epistemology (the theory of knowledge proposed by Karl popper), computation and evolution. His central tenets are the "many worlds" interpretation of quantum mechanics (in which everything that can ever happen does, in many parallel universes) and the the idea that the world is self-similar at many different scales, so that explanations that work at one scale also work at another. It's a deep and powerful book with much to like: I especially enjoyed Deutsch's demolition of the standard theory of scientific induction and of the Platonic view of mathematics (that it "just exists" in a kind of perfection which is independent of the physical world). He shows that mathematics and computation only work because they are physical processes which ultimately depend on properties of the real world. He develops this approach into the "Turing principle" (it is possible to build a virtual reality generator whose repertoire includes every possible physical environment) and a clear explanation of quantum computation as a process underpinning the evolution of the physical world. Deutsch also advances a strong argument that the mathematics of physical theories should be taken literally: even apparently "unphysical" solutions to equations often have physical interpretations and these should be taken seriously even when they are counter-intuitive. The book closes with a chapter on "The Ends of the Universe" which has a somewhat dated feel because it's based on the "Big Crunch" view of the eventual future of the universe. The current view is that expansion of the universe is actually accelerating and the Big Crunch is highly unlikely; as a consequence, the discussion in this chapter is unconvincing. Overall, the book explains and clarifies many important areas of science but readers must judge for themselves whether they accept claims based on the "many worlds" interpretation.

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.

Book will be easier to be read if you have basic understanding of physics and philosophy. it is not simple or easy to read. may have to read it many times to fully grasp and comprehend the ideas presented in the book.

Few people want to know the reality. David Deutsch helps you understand the world in which you live

Nice

The book is all based on very fictional idea of multiverse which is not coherent at all and does not have mathematical beauty of Quantum mechanics. Arguments why multiverse is not a real scientific idea has not brought which makes the book very much biased and no worthy of time.