For decades, proponents of artificial intelligence have argued that computers will soon be doing everything that a human mind can do. Admittedly, computers now play chess at the grandmaster level, but do they understand the game as we do? Can a computer eventually do everything a human mind can do? In this absorbing and frequently contentious book, Roger Penrose--eminent p For decades, proponents of artificial intelligence have argued that computers will soon be doing everything that a human mind can do. Admittedly, computers now play chess at the grandmaster level, but do they understand the game as we do? Can a computer eventually do everything a human mind can do? In this absorbing and frequently contentious book, Roger Penrose--eminent physicist and winner, with Stephen Hawking, of the prestigious Wolf prize--puts forward his view that there are some facets of human thinking that can never be emulated by a machine. Penrose examines what physics and mathematics can tell us about how the mind works, what they can't, and what we need to know to understand the physical processes of consciousness. He is among a growing number of physicists who think Einstein wasn't being stubborn when he said his "little finger" told him that quantum mechanics is incomplete, and he concludes that laws even deeper than quantum mechanics are essential for the operation of a mind. To support this contention, Penrose takes the reader on a dazzling tour that covers such topics as complex numbers, Turing machines, complexity theory, quantum mechanics, formal systems, Godel undecidability, phase spaces, Hilbert spaces, black holes, white holes, Hawking radiation, entropy, quasicrystals, the structure of the brain, and scores of other subjects. The Emperor's New Mind will appeal to anyone with a serious interest in modern physics and its relation to philosophical issues, as well as to physicists, mathematicians, philosophers and those on either side of the AI debate.

# The Emperor's New Mind: Concerning Computers, Minds and the Laws of Physics

For decades, proponents of artificial intelligence have argued that computers will soon be doing everything that a human mind can do. Admittedly, computers now play chess at the grandmaster level, but do they understand the game as we do? Can a computer eventually do everything a human mind can do? In this absorbing and frequently contentious book, Roger Penrose--eminent p For decades, proponents of artificial intelligence have argued that computers will soon be doing everything that a human mind can do. Admittedly, computers now play chess at the grandmaster level, but do they understand the game as we do? Can a computer eventually do everything a human mind can do? In this absorbing and frequently contentious book, Roger Penrose--eminent physicist and winner, with Stephen Hawking, of the prestigious Wolf prize--puts forward his view that there are some facets of human thinking that can never be emulated by a machine. Penrose examines what physics and mathematics can tell us about how the mind works, what they can't, and what we need to know to understand the physical processes of consciousness. He is among a growing number of physicists who think Einstein wasn't being stubborn when he said his "little finger" told him that quantum mechanics is incomplete, and he concludes that laws even deeper than quantum mechanics are essential for the operation of a mind. To support this contention, Penrose takes the reader on a dazzling tour that covers such topics as complex numbers, Turing machines, complexity theory, quantum mechanics, formal systems, Godel undecidability, phase spaces, Hilbert spaces, black holes, white holes, Hawking radiation, entropy, quasicrystals, the structure of the brain, and scores of other subjects. The Emperor's New Mind will appeal to anyone with a serious interest in modern physics and its relation to philosophical issues, as well as to physicists, mathematicians, philosophers and those on either side of the AI debate.

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## 30 review for The Emperor's New Mind: Concerning Computers, Minds and the Laws of Physics

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5out of 5Mark Lawrence–I've been reading this one since June and it's now 3 days til Christmas! Roger Penrose is a famous mathematician who worked with Stephen Hawking on black holes and who has done ground breaking work elsewhere (including on the surprisingly fundamental issue of tiling 2D spaces!). The book is about the nature of intelligence and whether it really can be an emergent property of algorithmic procedure (i.e. Turing Machines, i.e. computers as we know them). Many people believe that intelligence can aris I've been reading this one since June and it's now 3 days til Christmas! Roger Penrose is a famous mathematician who worked with Stephen Hawking on black holes and who has done ground breaking work elsewhere (including on the surprisingly fundamental issue of tiling 2D spaces!). The book is about the nature of intelligence and whether it really can be an emergent property of algorithmic procedure (i.e. Turing Machines, i.e. computers as we know them). Many people believe that intelligence can arise from sufficiently complex algorithms operating on sufficiently powerful computers. Penrose is in a minority that doesn't. In order to make his point Penrose starts with issues of non-computability. A Turing Machine represents every possible algorithmic computer (including all the ones we've made), and there are many questions (regarding whether certain processes will stop or not) that Turing Machines can be proved to be unable to answer. This relates to Godel's proof that in any formal system (like mathematics) it is possible to pose questions that can't be answered within the system. Penrose says that the human brain can answer many such unanswerable questions (in a similar way to that in which it discovers new mathematics) using inspiration. In order to consider how the brain might be capable of things that Turing Machines are not Penrose then spends 85% of his fat book on a tour through science. And I mean pretty much the whole of physics plus some more. This is of course a whistle-stop tour, through mechanics, relativity, electro-magneticism, quantum mechanics, the formation and death of the universe etc ... To someone with a physics degree it constitutes a refresher course. I'm worried that to pretty much any one else it would be dull and incomprehensible. Additionally, given that most readers will not, in the time and detail available, really grasp much of it ... it's fairly pointless. The basics/feel of his final arguments could have been delivered by a less extensive tour of the whole of physics. At the end of it Penrose needs to postulate a quantum mechanical source for the brain's proposed ability to do what a computer (of any Turing Machine sort (including quantum computers, apparently) can't. This is a hard sell as entanglement and other quantum phenomena don't seem to have macroscopic impact in a hot/noisy environment such as that brain. However, Penrose does lay out an interesting possible architecture for quantum gravity and the way in which the quantum and classical world may be unified within a theory. These suggestions also play interestingly into the business of time/the flow of time/the fact we perceive a present, past and future. And yes, at the end of it all he even manages to get his tiling into it. Most of all, for me, this a heartening book not so much for the solutions it offers but for showing/reminding me just how much we don't know and that there are plenty of dark spaces in our knowledge/theories where all manner of surprises (including ones about the nature of intelligence) may lurk. A good read wrapped around an over-long physics 101 that's too complex for pretty much anyone without a physics degree. [it should be noted that I do have a physics degree, a math-based PhD, and years of experience working on research problems in the 'AI' area.] Join my 3-emails-a-year newsletter #prizes ..

4out of 5Manuel Antão–If you're into stuff like this, you can read the full review. Physics and Computer Science for Laymen: "The Emperor's New Mind" by Roger Penrose Penrose certainly has a generous idea of his readers' mathematical ability. It's a kind of running joke among Penrose-fans: he always starts his books by saying you'll find it tough going if you haven't got a 12th Year (in Portugal)/GCSE (in the UK) in math, but that he'll explain it as he goes if you haven't. Twenty pages later you're on Gödel and confor If you're into stuff like this, you can read the full review. Physics and Computer Science for Laymen: "The Emperor's New Mind" by Roger Penrose Penrose certainly has a generous idea of his readers' mathematical ability. It's a kind of running joke among Penrose-fans: he always starts his books by saying you'll find it tough going if you haven't got a 12th Year (in Portugal)/GCSE (in the UK) in math, but that he'll explain it as he goes if you haven't. Twenty pages later you're on Gödel and conformable geometry. He doesn't do it deliberately; he really does believe his books are popular science. How can you not love him? I purchased an on-line kindle edition of this book back last year via Amazon and it was more about bringing myself up to date (I read it for the first time in 1991 when the book came out), although such things are never truly current due to Theories being debated and tested for very many years within Scientific Realms. Roger Penrose's books are as stated often inclusive of more mathematical devises than many books aimed at more laymen realms, so I often regard them as perhaps Bridging that gap between Solid Science Headaches and Laymen 'I read an article and am a common law know-all expert'.

4out of 5Manny–I suggested that one could imagine Albertine's gang in A L'Ombre Des Jeunes Filles En Fleurs as a kind of wave function of girls (see my review), and that made me think of The Emperor's New Mind. Given that it's all about quantum mechanics, I suppose it's appropriate that I have two different and completely incompatible reactions to it. On one hand, I am annoyed with Penrose. OK, he is a great genius in his own field, but why does that give him a license to come in and pronounce on the things I I suggested that one could imagine Albertine's gang in A L'Ombre Des Jeunes Filles En Fleurs as a kind of wave function of girls (see my review), and that made me think of The Emperor's New Mind. Given that it's all about quantum mechanics, I suppose it's appropriate that I have two different and completely incompatible reactions to it. On one hand, I am annoyed with Penrose. OK, he is a great genius in his own field, but why does that give him a license to come in and pronounce on the things I do, hardly even bothering to quote anyone who actually works in Artificial Intelligence? How would he feel if, say, Peter Norvig were to write a book on quantum theory, quoting only AI and computer science people, and making it sound like all the real quantum theorists were irrelevant? Many other AI people I know who have have read the book feel similarly. On the other hand, Penrose's suggestion that we should think of people's minds as quantum-mechanical systems is interesting. In fact, I'd go further than that: it's sometimes a useful thing to do in real life! At least, I find myself thinking that more often than you might suppose. Here's what I mean. Often, it makes little sense to ask whether a person "really" thinks A, or if they rather think its opposite, B. It's more useful to imagine that they are in a superposed state, which is a combination of A and B. You can perform an observation, and force them into an eigenstate: then they will indeed have to take a stand as to whether it's A or B. But doing this changes the situation; you may wish you'd been sensible enough not to carry out the observation, and just left things superposed. I think these observations are particularly relevant in serious romantic quarrels. Next time you are unfortunate enough to get into one, and if you are sufficiently interested in these issues to remember the experiment you're supposed to do, consider whether it's intuitively reasonable to model the other person's state as a superposition of "actually still loves you", "totally pissed off, had enough", and possibly other eigenstates. If you do think this is reasonable, consider whether your best strategy is to try and force them into an eigenstate, or leave it superposed. (I would LOVE data here). Personally, I think it's often best to try to leave the state superposed. Is this just a fancy way of describing a conflict-avoiding cop-out strategy, or is it some kind of insight? Again, my answer would be the one you so often get in quantum theory: both, even though they seem to contradict each other. As you can see, I am eagerly awaiting the publication of A Quantum Theory of Love. Please, won't someone hurry up and write it? But I think Penrose is the wrong guy to do this job.

5out of 5Ami Iida–The contents of quantum mechanics is the highest peak Among every physics books. Climax of this book Quantum gravity theory is not currently elucidated. Description of the structure of the brain is very weak, Currently, neuroscience is progressing rapidly Books in the system are better than this book. What is consciousness? The answer has not yet been answered. We should expect the book of the future of neuroscience. I also am going to read the recent books in this system. because fMRI and PET have been d The contents of quantum mechanics is the highest peak Among every physics books. Climax of this book Quantum gravity theory is not currently elucidated. Description of the structure of the brain is very weak, Currently, neuroscience is progressing rapidly Books in the system are better than this book. What is consciousness? The answer has not yet been answered. We should expect the book of the future of neuroscience. I also am going to read the recent books in this system. because fMRI and PET have been developed, human brain is easy to inspect and measure. Continuum hypothesis has not yet been proven. Since the beginning of the 20th century Quantum mechanics and molecular biology have been to lead the modern science. The last item quantum gravity theory and neuroscience. This is currently under investigation. The former is not yet known. The latter has been elucidated little by little by the spread of medical equipment.

5out of 5Ivan Vuković–First of all, I absolutely love Penrose. His style simply amazes me! There's this feeling that he wants to tell you SO MUCH and that he's trying hard to control himself so that he doesn't end up with a book several thousand pages long. Also, it's obvious that he enjoys science and mathematics on a really profound level. Those two things are really what kept me on the edge of my seat (when I wasn't reading while walking) while I was reading this book! As someone interested both in neuroscience and First of all, I absolutely love Penrose. His style simply amazes me! There's this feeling that he wants to tell you SO MUCH and that he's trying hard to control himself so that he doesn't end up with a book several thousand pages long. Also, it's obvious that he enjoys science and mathematics on a really profound level. Those two things are really what kept me on the edge of my seat (when I wasn't reading while walking) while I was reading this book! As someone interested both in neuroscience and mathematical physics I found this book absolutely brilliant and fascinating. If you came to this book from the purely neuroscience side and really don't like mathematics and physics, then MAYBE this book isn't for you, but personally, I like how Penrose isn't afraid at all to go into mathematically detailed stuff when he feels it is necessary to do so... and some things are not so trivial to understand! One more thing... I've seen many people (including a decent number of reviewers here) claiming that Penrose is nuts and that this book is filled with bollocks and nonsense, that he isn't logical, factual and whatnot... So, I was very careful and skeptical about this book and I have to say that people who say so are not fair to Penrose. Whenever he introduced something that wasn't widely accepted or something extremely speculative, he explicitly stated so, over and over again! Besides, it's not like he doesn't know what he's talking about... we should never appeal to authority as an argument (and I'm not doing that), but keep in mind that he isn't just some crazy old guy who doesn't know anything! Bottom line, you should form your own opinion about it, but I strongly recommend this book and I'm looking forward to reading Penrose's Road to Reality!

5out of 5Mitch–It's hard for me to rate this one: the bulk of the book was a great deal of fun, in the vein of "Goedel, Escher, Bach"; the concluding section seemed astonishingly ill-conceived. There's a big debate around this, but the connections he makes strike me as terribly wrong. Incompleteness doesn't prove the human mind does something no machine can do, and microtubules do not allow brain-wide coherence for special quantum-supercharged thinking that results in consciousness. But watching Icarus crash and burn mi It's hard for me to rate this one: the bulk of the book was a great deal of fun, in the vein of "Goedel, Escher, Bach"; the concluding section seemed astonishingly ill-conceived. There's a big debate around this, but the connections he makes strike me as terribly wrong. Incompleteness doesn't prove the human mind does something no machine can do, and microtubules do not allow brain-wide coherence for special quantum-supercharged thinking that results in consciousness. But watching Icarus crash and burn might be as much fun as watching him soar high and proud until then, so I certainly recommend this book to anyone who enjoys following a brilliant mind broadly exploring math and science.

5out of 5Peter–Here's what I think: Roger Penrose is wrong, and smart enough to convince himself he's right. I know he's smart because the journey he provides to his thesis is so rich with disparate concepts (I awarded an entire extra star just for the chapter that introduces quantum mechanics, for example). Unfortunately the logic that ties the whole thing together doesn't speak to me. The purpose of the book is to argue that strong AI is fundamentally impossible. He argues this from the last place I think is Here's what I think: Roger Penrose is wrong, and smart enough to convince himself he's right. I know he's smart because the journey he provides to his thesis is so rich with disparate concepts (I awarded an entire extra star just for the chapter that introduces quantum mechanics, for example). Unfortunately the logic that ties the whole thing together doesn't speak to me. The purpose of the book is to argue that strong AI is fundamentally impossible. He argues this from the last place I think is left for such a position. If we can simulate the action of a neuron, and if it's possible to know how neurons are connected, then in principle we can duplicate a brain and thus, it seems, a mind. Therefore, strong AI is possible, UNLESS brains depend on exotic physics not yet understood. He's very careful to distinguish between intelligence and consciousness: technical advances may make it possible for software to write symphonies, but that software, he claims, won't be conscious without taking advantage of certain quantum gravity effects which have not yet been observed and which are currently explained by no rigorously tested theory. There's a lot of suspense building to the thesis at the end, which he keeps well hidden up to then, intentionally or not. The author doesn't jump ahead to give a peek at how the chapter in question fits into the big picture; rather, he restates his thesis and promises again and again that he's about to prove it. In the end, the logic is underwhelming. Part of his argument actually rests on the impossibility of genetic programming, a technique that became popular a decade after publishing. I can easily allow the possibility that brains take advantage of exotic physics to perform computations; biology is a top down discipline, and in many respects the bottom, the basic physical reality of the phenomena in question, is nowhere in sight. But I'm less convinced that consciousness can't arise without those effects; and, anyway, it remains possible to simulate THOSE effects in a computer, and thus to build a strong AI. The whole thing smells like the scientific writings of an intelligent, scientifically read creationist, doing whatever logical gymnastics are necessary to prove the desired point, as much to oneself as to anyone else. One possibility the author allows for is that the quantum gravity effects he's postulating are deterministic, but non-computable. That is, that the state of a system, if it were known, implies how the state will evolve next with no possible randomness, yet the state in the future cannot be CALCULATED, even in principle. It's a neat idea that may or may not be sensible and I don't have any more to say about it. It's a good book. The math, physics, and computer science are all intensive, but Penrose is a good writer and pleasant to read. I don't regret the several weeks it took me to finish.

4out of 5DJ–First, the good. Penrose weaves tales of science, philosophy, and history that few others can, due to his wide-ranging and vast intellect. He touches on a wealth of interesting subjects in this book and his enthusiasm for them bleeds through the pages. In particular, this book offered the most illuminating introduction to entropy (in the "Cosmology and the arrow of time" chapter) that I have ever read. In short, before I read it, I didn't believe in the second law of thermodynamics. After I read First, the good. Penrose weaves tales of science, philosophy, and history that few others can, due to his wide-ranging and vast intellect. He touches on a wealth of interesting subjects in this book and his enthusiasm for them bleeds through the pages. In particular, this book offered the most illuminating introduction to entropy (in the "Cosmology and the arrow of time" chapter) that I have ever read. In short, before I read it, I didn't believe in the second law of thermodynamics. After I read it, I could interpret the entire world through "entropy goggles". In other books, entropy was some esoteric concept; here it is a beautiful and central feature of our universe. Now, the irritating. Penrose's stated goal in this book is to convince the reader that strong AI will not be realized. In other words, what human brains do, no computer ever could. Yet, however many fascinating ideas he introduces, his core evidence is little more than hope that what he does as a mathematician is unique; that human "aha!" moments are somehow distinguished from anything a computer ever does. Penrose fervently declares that he is no "formalist", claiming that the mere idea of a computer arriving at mathematical proofs makes the pursuit of mathematical truth "meaningless". Why? A computer may arrive at such a truth, but it is the human's role to make human meaning out of it. Meaning isn't some quality embedded into the fabric of our universe. It is a manufactured human ideal - a wonderful, enjoyable one at that. Penrose goes on to cite the vague notion of "reflection principles" (the imprecise methods by which the human mind discovers mathematical truth "upon reflection") as above and beyond algorithms. He uses these "aha!" moments as support for his argument that algorithms cannot possibly imitate what we do. Yet, how can we be so sure that these "aha!" moments do not arise from some complicated algorithm themselves? Perhaps, any human-created set of mathematical axioms will always be subject to "reflection principles" and only a more intelligent species could create a set for which there are no human-generated "reflection principles". Perhaps the notion of computability simply refers to a hierarchy of skill among complex adaptive systems. (If anyone knows of a book or research on such an idea, please let me know) Finally, on Penrose in general. Penrose's books tend to occupy a literary no-man's-land between popular science and technical writing: too technical for the average hobbyist yet not deep enough for a student in the sciences. It seems he's just too damn smart to recognize what falls into each category (for example, he might spend half a chapter explaining fractions and then breeze through Hamiltonians in half a paragraph). For me, he's best as a connector of mathematical and physical ideas after I've been formally introduced to them. As any good book should do, this one did leave me with a few questions (besides the above): Which is a deeper truth - math or physics? In reflecting on the story non-Euclidean geometry, what else are our evolutionary adaptations leading us to falsely assume? Has anyone checked whether Hamiltonians would be deterministic for computable universal constants and discrete input? Can we really separate dynamical equations from boundary conditions? Are not boundary conditions simply consequences of other not-yet-understood dynamical equations?

5out of 5Paul Kieniewicz–After scanning the host of negative reviews of this book, I feel compelled to speak my piece. I've read this book more than once, and often return to it and find a few more nuggets. Is seems to me that there are few other books that grapple as honestly with the nature of consciousness. The AI community, and materialist scientists who start with the premise that --- it's all in the brain; we don't know how or where but one day we will know, are the people that Penrose challenges. This book predic After scanning the host of negative reviews of this book, I feel compelled to speak my piece. I've read this book more than once, and often return to it and find a few more nuggets. Is seems to me that there are few other books that grapple as honestly with the nature of consciousness. The AI community, and materialist scientists who start with the premise that --- it's all in the brain; we don't know how or where but one day we will know, are the people that Penrose challenges. This book predictably annoys them. Since the book's publication in 1989, when Penrose asserted that the nature of consciousness will not be explained in materialistic terms, his prediction has proved true. We're no closer to understanding consciousness than we were then.Perhaps, as Penrose suggests, we're like scientists trying to build a perpetual motion machine, who still don't accept the second law of thermodynamics, stating that such a machine cannot be built. It's a blow to our human hubris when a scientist makes a proposition that begins with the words: "It is not possible..." Using arguments based on Godel's theorem of incompleteness, and the work of Turing, Penrose makes a credible case for why consciousness will never be explained in materialistic terms. In so doing he steps on a lot of toes. But maybe he's right. 2 plus 2 will never be 5 either.

4out of 5Samir Rawas Sarayji–I got so bored... too much formalism with having to explain all the mathematical and physical principles from the ground up before adding his own thoughts to the theme of consciousness. It all became too mucky to follow and keep track of, it felt more like a textbook for Penrose's ideas rather than an enlightening conversation that could offer me food for thought which I could digest.

4out of 5Tom–Penrose sets out to prove that strong AI (minds simulated on digital computer being equivalent to biological minds) is impossible. He argues that minds depend on a physical process which, while perhaps deterministic, is non-computable and therefore can't be simulated on a Turing machine. This was quite convincingly argued, and in the process Penrose takes you through probably the most comprehensible description of quantum theory that I've read in popular form. Not shying away from using the odd Penrose sets out to prove that strong AI (minds simulated on digital computer being equivalent to biological minds) is impossible. He argues that minds depend on a physical process which, while perhaps deterministic, is non-computable and therefore can't be simulated on a Turing machine. This was quite convincingly argued, and in the process Penrose takes you through probably the most comprehensible description of quantum theory that I've read in popular form. Not shying away from using the odd formula helps keep the ideas concrete and generally didn't freak out this reader too much. His reason for covering so much physics in order to explain his opinion on AI is that he thinks the process that turns quantum physics on the very tiny scale into classical physics on human scales is the non-computable process essential to consciousness (and is necessarily tied to quantum gravity). The discussion of the limitations of current theories seems much more insightful than the typical very speculative and fantastical projections of possible future physics found in popular cosmology. In particular, Penrose makes an interesting prediction about a future more complete theory: it will be time asymmetric (whereas current theories don't care what direction you run time in), and a low entropy start to the universe will be an essential feature of it (explaining the 2nd law of thermodynamics). He does have the (rather odd) idea that the 'platonic world' of mathematical truths can be reached from the mind (via this non-computable physical process), which is how mathematicians can 'see' the truth of mathematical propositions which would stump a purely algorithmic mind (since that algorithmic mind can't figure out the truth of its gödel sentences). I think it is more likely that these propositions are being analyzed in a more heuristic and error-prone way. But this implies cognitive closure which would be a shame. This book didn't resolve any of my philosophical problems with consciousness... Anyway, you should read this.

4out of 5G.R. Reader–I did a back-of-the-envelope calculation and told Roger that the decoherence times were at least ten orders of magnitude too low for the brain to be a quantum computer. No response. Then Max did it more carefully and said they were twenty orders of magnitude too low. Any advance on twenty? Sigh. I love Roger, but sometimes he just won't listen.

4out of 5kaśyap–This is a great mathematical book, which goes deep into many mathematical and philosophical ideas.I was 17 when i first picked it up at a library and this book was my introduction to many mathematical concepts and quantum mechanics. The basic premise of the author in this book is that human consciousness cannot be simulated computationally.his hypothesis that the human brain is a quantum-mechanical structure is very interesting. Not an easy read, but definitely worth going through.

4out of 5Douglas–I read this book when it first came out and I was still a student of science so my memory on specific details is sketchy. There is no doubt that it is interesting and lively. I recall agreeing with Penrose's skepticism about artificial intelligence through his discussion of the Chinese Room Problem and the idea that if it were possible to write down the "program" of a person's mind in a book then the book, in a very slowed down sense, would be intelligent. From this I recall that his skepticism I read this book when it first came out and I was still a student of science so my memory on specific details is sketchy. There is no doubt that it is interesting and lively. I recall agreeing with Penrose's skepticism about artificial intelligence through his discussion of the Chinese Room Problem and the idea that if it were possible to write down the "program" of a person's mind in a book then the book, in a very slowed down sense, would be intelligent. From this I recall that his skepticism is about what some call the Strong AI hypothesis, which the Chinese Room Problem and the example of the book illustrate. His argument is that the functioning of the mind is inherently a quantum phenomenon and, because of the indeterminacy of states inherent in quantum systems, the mind cannot be embodied in a machine (like a Turing machine) that progresses through definite states. In fact, Penrose (again from distant memory!) says that the human mind is uniquely and inextricably bound to the human brain. Thus all the grandiose claims of the proponents of AI are in a way like the praises the fabled naked emperor receives from his courtiers as he bestrides his throne room and thus the book's title. All of this is very good and, I think, weakens the plausibility of materialism which is the philosophical pedestal on which most scientists stand; though I realize this was probably not Penrose's intention. (It weakens it because it illustrates a reductio ad absurdum of the materialistic point of view.) Another interesting book, expressing skepticism toward AI is Hubert Dreyfus', "What Computers Can't Do". Dreyfus is a phenomenologist and tackles the problem from that point of view and not one based on modern physics.

5out of 5Arko–This is the first book of Sir Roger Penrose that I read by now and it left me mesmerized by the originality of his ideas no matter how much speculative they may be. Sir Penrose is a mathematician of first rate and it is very evident from his take on the hard problems which is beyond the mainstream approach of physicists. I am very much biased towards new ideas that can knit a multitude of problems together yet possessing a scientific ring of falsifiability, predictability and testability. This b This is the first book of Sir Roger Penrose that I read by now and it left me mesmerized by the originality of his ideas no matter how much speculative they may be. Sir Penrose is a mathematician of first rate and it is very evident from his take on the hard problems which is beyond the mainstream approach of physicists. I am very much biased towards new ideas that can knit a multitude of problems together yet possessing a scientific ring of falsifiability, predictability and testability. This book was written back in the late 80s with so rich ideas which can leave one thinking about it even today. In this book the author speculates an approach to answer the nature of consciousness which necessitates a modification of quantum and classical physics to an unification of both. Such unification is the holy grail of physics and much work is done on it and still ongoing. But the approach which Sir Penrose posits is quite a different one from the conventional line of thought of our present times. Moreover such approach ties not just classical and quantum worlds but also that of our consciousness as well. Although very speculative and much work needs to be done on this (even the author presently has somewhat moved on from his theory of one graviton criterion presented in this book) the essence of his approach remains the same and active research is being done at present. This approach being a gravitational collapse of the quantum wave function. To describe the book: Firstly the author questions the possibility of present day digital computers of having a mind or not. Such computers are run on algorithms which much of our brain functionality also does however the attribute of a conscious interpretation or judgement need to transcend this algorithmic nature and be non-algorithmic. The author describes computers that pass the Turing test and AI with complex algorithms have a good calculation power but the essence of understanding is something non-computational that remains lacking in these machines. The Author then delves into the meaning and details of algorithm, stretching to its limit of the most important insolubility of Hilbert's Halting problem of finding a mathematical procedure to ascertain the solution of all mathematical problems belonging to broad well defined class. It turns out to have no general algorithm to find such solutions in general for various mathematical problems. The famous incompleteness theorem given by Kurt Gödel does present to us the very limit of formalism of any one kind in particular which is applicable for all formal systems nevertheless. There are problems of Hamiltonian circuit and travelling salesman problem which belongs to the category of problem whose solution doesn't have an algorithm in specific determined time range. These are termed as NP complete. The more general algorithms being referred as P which possess algorithm for its solution in deterministic time. As of now P and NP are understood as different. Also the famous mathematical problem of tiling in which the author himself is a significant contributor towards aperiodic tiling structures, has no algorthimic decision procedure of its solution. Armed with all these concepts and the famous branch of non-recursive mathematics, the author posits that there should be a non-algorithmic nature of our consciousness which is much capable of judgement and insights. The best part of reading books by such high rank mathematicians and physicists as the author himself is that the reader's basic ideas in the field of mathematics and physics gets well strengthened. Sir Penrose magnificently described the world of mathematics , classical and quantum physics in each of which there are hints of non-algorithmic , deterministic but non-computational & non-local attributes respectively. Penrose is a Platonist giving the timeless realm of mathematical world a certain reality of its own. Finally the author arrives at his speculation namely one graviton criterion. Here Penrose tries to provide a possible mechanism as to how the complex weighted linear superposition of quantum wave function collapses to form a observable aspect of our classical world out of the several orthogonal alternatives which coexists in quantum world giving it a non-local feature. Locality gets imbued , according to this theory , when the difference between initial and final mass distribution as a part of the superposition achieves a gravitational field difference to that of 1/100 of Planck mass. With several interesting phenomena of quasicrystals where a 5-fold symmetry ( tiling in 5fold symmetry was worked out by Penrose ) occurs need a nonlocal quantum superposition description to attain it in a minimum energy. With such an analogy the author speculates the growth and contraction of dendrites (having synaptic connecrions) of neurons of our brain can occur in a similar fashion then such a superposition would collapse upon meeting the one graviton criterion within a certain small amount of time. Within this time several nonlocal activity may be achieved simultaneously which when collapses takes the form of a judgement or conscious decision. This collapse which slides from the deterministic Schrödinger wave function(superposed) evolution to the stochastic reduction of wave function requires a new quantum gravity theory with a non-algirithmic property. Also in this book Penrose subtely touches on an interdependency of quantum state vector reduction and a null value of tidal flow field given by the Weyl curvature tensor of the equations of the famous Einstein's general theory of relativity. This constraint of Weyl curvature tensor being zero is theorized to be present at the Big bang singularity imparting our Universe the second law of thermodynamics which states that irreversible events occur towards a higher entropic state with a lower entropic state preceding it. The nature of brilliant insights or spark of ideas which comes up in our mind altough having a non-algorithmic nature it nevertheless depend on the otherwise various algorithmic/computational activities of our brain carried out involuntarily. This book is a collection of several deep and insightful ideas. I have seldom written such a lengthy review in goodreads owing to my inability to manage time. But for this book I lost track of time and length of my review. This book is a mandatory read for those who strive for diverse ideas for various mysteries of our reality.

4out of 5keith koenigsberg–Another longtime companion of mine, this book is by turns brilliant and exasperating. It's a bulky layman's discourse on Artificial Intelligence, seeking the answer to the question "Can a computer ever possess true intelligence?" Its brilliance lies in fascinating and lucid coverage of a variety of subjects in mathematics, classical and quantum physics, relativity, and all of the philosophical underpinnings. Unfortunately in the tumble of information Penrose neglects to pull the threads together Another longtime companion of mine, this book is by turns brilliant and exasperating. It's a bulky layman's discourse on Artificial Intelligence, seeking the answer to the question "Can a computer ever possess true intelligence?" Its brilliance lies in fascinating and lucid coverage of a variety of subjects in mathematics, classical and quantum physics, relativity, and all of the philosophical underpinnings. Unfortunately in the tumble of information Penrose neglects to pull the threads together and support a thesis. I always looks back, say, at a chapter on the Mandelbrot set or Godel's Theorem, or whatever, thinking - that was great and fascinating, but what does it have to do with the nature of intelligence? Exactly what is the link between black holes and brains? Penrose's thesis - that human thought and self-awareness are non-algorithmic - is supported indirectly, if at all.

5out of 5Kevan–My reaction to this book and its follow up, Shadows of the Mind, were pretty much the same. Yes, it's true we can't reconcile gravity and quantum mechanics Yes, reconciling how intelligence arises in a purely mechanical system is not understood Yes, Godel's incompleteness stuff and Turing halting stuff are weird and not at all obvious But, no, I am very far from convinced that a mechanism that allowed us to reconcile General Relativity and Quantum Mechanics would allow us to understand how intellige My reaction to this book and its follow up, Shadows of the Mind, were pretty much the same. Yes, it's true we can't reconcile gravity and quantum mechanics Yes, reconciling how intelligence arises in a purely mechanical system is not understood Yes, Godel's incompleteness stuff and Turing halting stuff are weird and not at all obvious But, no, I am very far from convinced that a mechanism that allowed us to reconcile General Relativity and Quantum Mechanics would allow us to understand how intelligence can arise and avoid the Godel paradox That being said, Penrose is a tad smarter than I am. Maybe it's a case of the reader blaming the authors for the reader's shortcomings

4out of 5Michiel–A book about turing machines, Gödel's theorem, cosmology, quantum mechanics, neurology and consciousness? I was sold! Penrose is, IMHO, the best writer about physics. His style is friendly and relaxed but thorough. I do not follow his thesis that it is not possible to construct hard AI and brains need an quantum physical element to be understood. But this book deals with such interesting subjects and themes about the universe and our place in it, it is impossible not to be fascinated.

4out of 5Sandys Nunes–4out of 5Adeyemi Ajao–This book is fantastic for two reasons: 1. Its central idea: That the nature of human thought is ultimately non-algorithmic...a fascinating point of view in this AI dominated era 2. Being privy to the inner workings of Roger Penrose's mind. In an era in which scientific specialization is the norm, it is refreshing to read someone that jumps from chaos mathematics to computing and quantum gravity to answer questions about consciousness. If Hesse's "Glass Bead Game" was real, Roger Penrose will no This book is fantastic for two reasons: 1. Its central idea: That the nature of human thought is ultimately non-algorithmic...a fascinating point of view in this AI dominated era 2. Being privy to the inner workings of Roger Penrose's mind. In an era in which scientific specialization is the norm, it is refreshing to read someone that jumps from chaos mathematics to computing and quantum gravity to answer questions about consciousness. If Hesse's "Glass Bead Game" was real, Roger Penrose will no doubt be one of its most accomplished players

5out of 5Louisa–Computers can defeat humans in a game of chess, and perform mathematical operations much faster than humans can. A robot can be built that detects when its batteries are running low and when this happens, goes off to find a power socket to plug itself in and recharge. Computers can be programmed to answer questions as a human being would. But can a computer solve every problem that a human being can solve? Could computers ever be aware of, and actually understand what they are doing? Could the e Computers can defeat humans in a game of chess, and perform mathematical operations much faster than humans can. A robot can be built that detects when its batteries are running low and when this happens, goes off to find a power socket to plug itself in and recharge. Computers can be programmed to answer questions as a human being would. But can a computer solve every problem that a human being can solve? Could computers ever be aware of, and actually understand what they are doing? Could the entire contents of the brain be stored on a digital device? To state that a computer behaves as a human being, is it enough that it gives us answers that are indistinguishable from those of a human being? Can computers actually be intelligent; will they feel, think, and have minds? The defenders of "strong-AI" say yes, but Penrose doesn't think so. He argues that there is a lack of understanding of the laws of physics at the scale of the human brain that prevents us from penetrating the concept of "mind" in physical or logical terms. In other words, there is a piece of the puzzle missing. To explain his viewpoints, Penrose takes us on a ride through the developments in artificial intelligence (as it was in the end of the 1980s when he wrote the book), the workings of the Turing machine, the foundations of mathematics and Gödel's theorem, quantum theory and electromagnetism, and he does that really well. Penrose is a very creative thinker with an astonishing mastery of many fields of science. It is therefore disappointing that what follows in the last few chapters is no more than speculation; his suggestion that consciousness is the result of quantum gravity effects in certain areas of the human brain has since been refuted by other scientists. I am still glad to have read The Emperor’s New Mind, as it provides an interesting contrast with Hofstadter's views on artificial intelligence, and I certainly learned a lot from the science chapters. However, I doubt whether it is worth going through such an awful lot of math for a somewhat outdated theory.

4out of 5Shivnarayan–Well, I am still dizzy; It feels like emerging out of a concussion! Amazing read and I indeed loved it, the only problem is you can't read it like a novel because of its information overload - the amount of information that is littered on each page is just phew! Nevertheless, it was sort of warm up exercise for me for the things that are to be completed in the near future... Loved the whole experience: exciting, exulting, enthralling!

5out of 5Philip Cartwright–The sections of this book where Penrose outlines recent scientific and mathematical developments are excellent. Unfortunately, his philosophical reflections on those developments are rudimentary and clumsy to say the least. And his central claim that quantum mechanics holds the key to free will is just silly.

5out of 5Gibb–tldr; (well, I read a bit... zzz)

5out of 5Jonathan Chuang–Although this book brought to my attention some interesting ideas, I felt that as a whole, these ideas weren't communicated very succinctly or convincingly. I was constantly annoyed by the copious amounts of speculation. In the meanwhile, the main chunk of the book that sought to provide an adequate background was pretty okay, but Penrose has a penchant for overexplaining certain trivialties while underexplaining other more important points. Penrose also has very strange views wrt to the philoso Although this book brought to my attention some interesting ideas, I felt that as a whole, these ideas weren't communicated very succinctly or convincingly. I was constantly annoyed by the copious amounts of speculation. In the meanwhile, the main chunk of the book that sought to provide an adequate background was pretty okay, but Penrose has a penchant for overexplaining certain trivialties while underexplaining other more important points. Penrose also has very strange views wrt to the philosophy of mathematics, he seems to believe in the notion that mathematics is "out there" in a perfect Platonical sense, although som eof his arguments convinced me of a soft Platonism -- idk what label philosophers attach to it, but it's the idea that emergent mathematical properties, which have their own "beauty" or "platonic truth" are embedded within the elegant and symmetrical structure of our mathematical axioms, but are not separate from them. In other words, truth is found in the axioms, and although not necessarily provable from axioms alone, can be ascertained by an external (self-referential?) observer. Overall it left me confused but enlightened in my own way - I am more interested than ever in consciousness and brains. So for my own sake, I'm gonna revisit the book from the beginning and enumerate my thoughts. ----------------------------------------------------------- Chapter 1: Can a Computer have a mind? The book begins with an introduction to AI, listing various ways to determine if a computer possesses consciousness. So there's the turing test, which essentially says that any simulation of an output of consciousness that is indistinguishable from the output of any odd human being, under the judgement of an observer, is good enough to be called "conscious". Then there's a refutation, Searle's chinese room, which essentially plays on the necessity of 'understanding' or 'meaning' in the process of consciousness. I haven't given these enough thought, but obviously the first one is unsatisfactory because you have to specify a domain and range of "acceptable outputs", which is essentially information that can be subject to algorithmic laws. I guess you could put on trial an algorithmic/statistical programme by demanding from it certain acts of creativity and a certain flexibility that we would normally associate the imagination, a feature of the mind often thought of as the pinnacle of human evolutionary achievement, but programmes such as the jeopardy flouncer have shown just how easily (well maybe not for its programmers) a programme can simulate lateral thinking. It does so by drawing on a countless database of human culture and ingenuity. Essentially stuff like Searle's Chinese room support the argument that any attempt at AI via algorithms produces a philosophical zombie. I sort of accept this for the most part, except that there's a possibility that through a modular algorithm possessing components of complex self-referrence is all that's necessary for a digital computer to perceive itself, and perhaps the sensation of being in the front seat of awareness is nothing more than this sort of self-referrence towards one's internal states. I for one am troubled by this notion, and it is still difficult to fathom what exactly this self-referrence would be. Perhaps it is a constant comparison of perception with stored data in a space which is constantly, in turn, perceived. But it's difficult to say just at what point it is that awareness would suddenly emerge. Chapter 2, 3 & 4: Algorithms and Turing Machines | Mathematics and Reality | Truth, Proof and Insight These chapters were a little less problematic. I got an introduction to Turing machines and the binary language we use at the mechanical(mainframe???) level of computation. Got my first introduction to incompleteness and uncomputability, which was almost astoundingly trivial. It was just like that game we play with language: "this statement can't be proved" or "this statement is false". I am still in the dark about the full ramifications of this for mathematical truth, or 'insight'. Nevertheless, I was genuinely surprised by the fact that we, as external observers, can decide the provability (or truth) of a statement "If this is a statement that can decide the unprovability of all statements, then there is no statement that can prove this statement". The trick is that we are able to see that the statement is indeed unprovable, but the statement within the algorithm/formal system is not. or something like that. I had a moment of lucidity but I think it's now been lost. But the discussion of the Julia sets and the Mandelbrot set was pretty convincing for me, at least enough to adjust my position from strict formalist to one more accommodating of "external" mathematical truth. Before this I had always thought that enumerabillity of a set meant the enumerabillity of its complement, but apparently not, although I couldn’t grasp the significance of this. There was also in the book a subsegment on complexity theory and coarse-grained algorithmic models of aggregate behaviour which I later (perhaps going off on a different tangent) found out a little bit about. Chapter 5 & 6: The classical world | Quantum magic and Quantum Mystery Mostly for these chapters I got smatterings of stuff I understood only implicitly but not at all in a rigorous way. Nothing much to be said. Chapter 7: Cosmology and the Arrow of Time I finally got some clarification of what entropy means: the aggregate dissipation of ‘order’ in a system. The effects of entropy, are not, in actuality, irreversible if left on its own, just that such a scenario is highly improbable. So order here has less to do with energy than with “a state of probabillity” or something. Something to do with time and random motion. Though I didn’t really get white holes or phase space of particles… Chapter 8: In Search of Quantum Gravity I didn’t really get QM so it’s difficult to say what I gleaned from this chapter. I remember learning that the probabillities of QM don’t seem to split when moving backwards in time, but instead seem to conjoin into one state. Is this like some sort of “supraposition”. Irdk don’t trust myself on this. Chapter 9: Real Brains and Model Brains This was written at a time (I think) before the FMRI. Nevertheless, some interesting discussions about language, and multiple-regions of conscious awareness. I think it is silly to think that consciousness developed in tandem with language and is therefore privy to human beings. Language merely allowed for an explicit account to be made of one’s consciousness, forcing perhaps one’s societally aroused “self-consciousness” due to the awareness of other ‘minds’ in a very strong sense. I thought it was prety cool that in split brains, each side may only be dimly aware of the conscioius activities of the other. Also, isn’t it the case that emotions are only useful to a conscious animal. Thus it must be the case that emotions are essential to consciousness, or at least the part of it that deals with “meaning” and “importance/salience”. (actually I’m mistepping here. Emotions also have physiological effects) But it’s interesting nonetheless that a whole spectrum of information is processed in a non-conscious way, whether algorithmically or otherwise (what is otherwise? Analogue?). This part of the brain is probably no less interesting, but is definitely easier, at least, to compare with a computer fitted with an appropriate programme. QM is suggested as a possible source of free-will. Personally I’ve found it useful to think of it this way. Seemingly deterministic systems are only the aggregate behaviour of random processes. The emergent indeterminism of our brains, by contrast, somehow have arisen in an ordered fashion, not totally random, not strictly determined, and is scientifically categorised as “complex”. One thing I was struck by recently was that if we were completely animal, we would be driven by our emotions entirely, and if we were able only to reason based on non-emotional, algorithmic assessments of our environments, we would be entirely bound by reason. Somehow our freewill lies in our abillity to mediate our emotions with reason, in turn, and for emotions to colour our reasons. (reason here referring to our ability to form and work out cause and effect -- or cost and reward -- within a functioning model we have.) Chapter 10: Where lies the Physics of the Mind? It is an interesting idea that there must have been a evolutionarily viable reason for consciousness to emerge. I think one reason is that algorithmic systems simply cannot assess meaning of environmental changes as well as a conscious awareness can. If environmental awareness was coded directly into the brain, the abillity for generating new ideas not found directly in perception would be absolutely limited. Look at what consciousness has given us instead: the ability to adapt complex spatio-temporal models of the world that suit our needs. It gives us true imagination and creativity, much unlike the derivative statistical model of the Jeopardy-playing programme. It has also given us the ability to interact well with others of our species, and by extension, a better understanding of ourselves. The power of the human mind does not lie in its ability to reason (statistically) based on environmental changes, but its ability for unreasonable leaps in the imagination. Just look at culture -- an essential part of communal organisms: the massive leaps in understanding we have of the world are not at all physically encoded through genes, or algorithmically processed, but are conceptual -- we inherit habits and understanding from others, very very quickly, through our conscious "modelling". We are able to form spatio-temporal narratives about an otherwise chaotic world. I believe some scientists have recently pioneered work in "dynamic quantum modelling" or something like that. The idea is to use this unique ability of the brain to identify special structures that we would like to study, a tactic applied to big data where there is a lot of noise. I have a feeling consciousness lies precisely in this conceptual ability to model. Penrose in some sense thinks it is silly and says a video-camcorder pointed at a visual image of itself does not have self-awareness. Of course not. It does not have an internal modelling abillity. Unfortunately there's no saying what the substance of this conceptual modelling is. It seems, from introspection, that a model is simultaneously formed while being perceived, rather than being similar to a computable "algorithmic model". Therein lies its flexibility. Okay, so what then? There still remains a question whether conscious awareness can result from the appropriate algorithms. While I find the possibility disturbing, I don't find Penrose's objections very convincing. Except for the fact that turing machines have not been fed algorithms in a composite enough way to produce this elastic, highly visual and emotionally charged modelling throughout the past 60 years, there is nothing to say that it cannot resolve this impasse in the foreseeable future. Human "insight" is not at all some sort of algorithmic process, I believe, and neither is it statistical. It's associative, what ever that means. It takes disparate parts of conceptual models and combines them in the appropriate way we're searching for. Furthermore, just because an algorithm cannot prove all the statements within itself does not mean it cannot make non-logical guesses. This is essentially the basis of human reason, imo, the ability to arrive at the correct conclusion through a non-algorithmic process, even while the engine of that process may itself be algorithmic. So non-algorithmic decision making does not preclude the fact that its underlying structure is algorithmic in a certain way. Why can't pure consciousness with all its undecidability emerge from some non-static algorithmic process which constantly corrects and destabilises itself? Isn't that the function of consciousness, evolutionarily? To arrive at spontaneous and creative decision-making? Argh so many unanswered questions, and so many dim thoughts. Perhaps I should take a nap and give my conscious awareness a well-deserved break.

5out of 5Damon Taylor–This was a tough one. I appreciate in the first instance, of course, that the substance of the work is well beyond me - and having now finished the book I cannot help but feel I am marred by misapprehension. I have therefore taken that into account when giving a review. The unfamiliar but generally observant reader may have a working understanding of some of the ideas that form the core of Penrose's argument - Turing machines and computation; quantum gravity; split brain experiments, and so on. This was a tough one. I appreciate in the first instance, of course, that the substance of the work is well beyond me - and having now finished the book I cannot help but feel I am marred by misapprehension. I have therefore taken that into account when giving a review. The unfamiliar but generally observant reader may have a working understanding of some of the ideas that form the core of Penrose's argument - Turing machines and computation; quantum gravity; split brain experiments, and so on. However, the length and depth of the work makes a mockery of the impressions the casual reader may have gleaned. That was certainly my experience, in any case - madly comparing my own, gossamer thin understanding of, say, Godel to its position as employed by Penrose. For this reason, it is well to take Penrose's early advice and take the time to understand and familiarise yourself with the equations and concepts employed. They are not there for window dressing, and in the final chapters these strands are braided into Penrose's conclusion - that 'correct quantum gravity' (a homebrew putative theory which explains how and why curvature of space time carries the features that it does) will, if proven, give us the technical skill necessary to explain consciousness. To so aggressively summarise, without context, what is a complex form of argument is unfair of me, which is why my review is not about this conclusion. Rather I have decided to judge this book on its capacity to contribute to my own personal response to the mind body problem. That is: is the me that is me - the thinking feeling awareness that *feels* unconfined while very clearly hemmed in by the brain - manifest only during the specific functions of a specific assemblage of specific cells? In other words, if a carbon copy of me was to be summoned into existence, would he and I share a consciousness? Or is that a distinct, discrete consciousness to my own - another, thinking feeling thing. Penrose's book provides insight in several respects. Firstly, much of the early text is occupied with the Strong AI theory - that consciousness is a consequence of complex computational systems, and therefore consciousness is not linked to a specific assemblage of human brain cells but is rather an emergent property of any complex system, regardless of medium. Penrose disagrees - he goes to great lengths to establish that computations of this kind cannot be the cornerstone of consciousness. This therefore encourages the reader to at least accept that something non computational, but still mathematical, about the way in which the brain consciously perceived information. The second is a personal challenge - Penrose marshals evidence against the claim that consciousness is bound up with language by providing examples, such as split brain experiments, of cases in which language manipulation and conscious thought were shown to be distinct. This is a personal challenge because I find it seductive and intuitive that consciousness and language should be tightly wound. Again, without technical expertise, fidelity I cannot provide to my intuition, so I shall not mount a counterargument. However, I should say that the case is hard to ignore, and one which will inform my views on the subject going forward. So how does this book contribute to my self-searching question set out earlier? - well I cannot say. Rather it has challenged my own proto-conclusions and views on the topic. As ever, the only real answer is to continue reading and writing - to expand my library and hope, someday, to better consider the world in which I live. For that, Penrose deserves 4 stars at least.

4out of 5George Marshall–So, the last chapter felt like grasping. Putting that aside, the book is well written. The author's descriptions are vivid, graspable and powerful. I gladly look forward to reading more by Penrose, whether I am more inclined towards a strong AI bent or am eventually convinced of his speculations. I do feel the weight of his reasoning - the challenge: can an algorithm's complexity really give us intelligence, and more, consciousness? Whether quantum effects (or some deeper truth bridging the gravi So, the last chapter felt like grasping. Putting that aside, the book is well written. The author's descriptions are vivid, graspable and powerful. I gladly look forward to reading more by Penrose, whether I am more inclined towards a strong AI bent or am eventually convinced of his speculations. I do feel the weight of his reasoning - the challenge: can an algorithm's complexity really give us intelligence, and more, consciousness? Whether quantum effects (or some deeper truth bridging the gravity/wave collapse picture) are the answer remains to further study. While initially I felt astounded by the audacity of a placement test for physical laws (superb, useful and tentative), it was an effective tool throughout the book. Even if one is uninterested in consciousness or AI, but appreciates physics, there is a lot to recommend here. It covers in breathtaking fashion both classical and quantum mechanics, though necessarily at a level removed from intense study of equations. Information theory is handled in part, though I kept feeling it should intrude more heavily. The book poses good questions and repeatedly gives a feel for what we don't know. Its optimism that we can find the answers, and that the answers will be better and more wonderful than we have settled for, is contagious. Bottom line, I enjoyed it immensely and think you, my friends, will too.

4out of 5Jake–Good introduction to common theoretical physics topics. An eh introduction to neuroscience. A good introduction to the mind To compare it to Tegmark's "My mathematical universe" due to that book being a very similar text within the genre of "intro theoretical physics", penrose seems somewhat more open minded, but also much stranger. Much much stranger. He asserts the existence of plato's forms (in some iteration) , and even stranger, and goes so far as to propose the relation of quantum phenomena Good introduction to common theoretical physics topics. An eh introduction to neuroscience. A good introduction to the mind To compare it to Tegmark's "My mathematical universe" due to that book being a very similar text within the genre of "intro theoretical physics", penrose seems somewhat more open minded, but also much stranger. Much much stranger. He asserts the existence of plato's forms (in some iteration) , and even stranger, and goes so far as to propose the relation of quantum phenomena to sentience. Tegmark talks to the reader like they are a somewhat intelligent freshman in college, while penrose seems to presume the reader has a pretty solid grounding in physics. Maybe even on par with that of third year physics student. He often would state "I'm sure the reader is familiar with.." and then start talking about some esoteric topic that only physicists would know about. It makes you wonder about who he wished to read this.. Penrose has a higher stress on quantum mechanics and math, tegmark on cosmology and the multiverse.. Overall, even though I gave tegmark higher stars (due to my emotional response after first having read that), I preferred this text..

4out of 5Roberto Rigolin F Lopes–We are in 1989, Penrose starts with the hypothesis that consciousness is non-algorithmic therefore cannot emerge in computers. He is challenging AI researchers with a great deal of speculation before multi-core processors, the web and smartphones. But he did his massive homework and there is a sense of intellectual honesty throughout this book. He starts with Turing machines, passing through Gödel’s theorem, fractals, classical physics, quantum physics, the human brain and to end with the physic We are in 1989, Penrose starts with the hypothesis that consciousness is non-algorithmic therefore cannot emerge in computers. He is challenging AI researchers with a great deal of speculation before multi-core processors, the web and smartphones. But he did his massive homework and there is a sense of intellectual honesty throughout this book. He starts with Turing machines, passing through Gödel’s theorem, fractals, classical physics, quantum physics, the human brain and to end with the physics of the mind. Wow! The whole thing is edifying because he always point-out that physics in an unsatisfactory state (inconsistent) but keeps going with his speculative guesses. Perhaps his hypothesis is probably wrong for the same reason physics is currently inconsistent (classical + quantum), our machines are not so smart and we don't know how to simulate brains. That is, we are not so intelligent as we think!

4out of 5CharlieSz–This was one of my nemesis books. It's been on my shelf for about 25 years and I've made 2 or 3 attempts at it in that time. I took a slightly different approach this time and it was actually a much better read than I expected. The first parts are filled with hugely complex ways of looking at concepts that I thought I was already familiar with. It was (mostly) comprehensible as I read it, but I don't know how much I could repeat from memory now that I'm done. The author pretty much lost me at the This was one of my nemesis books. It's been on my shelf for about 25 years and I've made 2 or 3 attempts at it in that time. I took a slightly different approach this time and it was actually a much better read than I expected. The first parts are filled with hugely complex ways of looking at concepts that I thought I was already familiar with. It was (mostly) comprehensible as I read it, but I don't know how much I could repeat from memory now that I'm done. The author pretty much lost me at the end, where he's finally getting to the point of the whole book. His careful, pedantic style softens considerably as he goes off in a number of highly speculative directions. I see where he is heading with it, but I think he's taken too many liberties to get there, which leaves the conclusions somewhat muddy and, in the end, inconclusive.