xhg0998@uxa.cso.uiuc.edu (09/07/90)
This review and the follow-on comment are dedicated to those people who think independently on questions like "how human brain works" and "can computer have a mind". Please forgive me about the odd technical words in th articles. But I do think everybody should know them since they are the most important concepts in human knowledge. You`d better save your time if you only read but do not think. ============================================================================ The Emperor's New Mind Written by Roger Penrose Reviewed by Xiaoping Hu From the title, you see that Dr. Penrose isn't so friendly to the proponents of strong AI, if you ever know what the Emperor's New Clothes are. In return, Dr. Penrose has brought attacks upon himself: in a lecture at a university in New York, some strong AI guys got so angry with him that they almost split his pants! It seems a fashion, or simply it is profitable, that a renowned scientist writes a popular book for the less educated, trying to make the mass understand the complicated science, or to push his own influence to social life, or to make money, whatsoever. Following Stephen Hawking, another distinguished physics theorist, Prof. Roger Penrose at Oxford University, presented us this best seller, which surely caused a shock not only in the reader's circle, but also in the computer society. In this deliberately conceived book, Dr. Penrose first reviews the major concepts and principles underlying computer science, the past achievements of AI, the opinions of the so-called strong AI and its approaches, and the main controversies that he will discuss in the book. Then learned Penrose takes us to a journey of modern mathematics. He uses daily language to tell us what algorithm and Turing machine are and how they work. He will never forget to emphasize Goedel's incompleteness theorem and Church-Turing thesis with which he joyfully describes the failure of Hilbert in an attempt at finding a universal algorithm for determining trueness of any mathematical proposition. Prof. Penrose is not content with stopping there. He further leads us to the depth of mathematical Kingdom to show the wonderful scenario there: Mandelbrot set, Fermat Conjecture, Goldbach Conjecture, Formalism and Intuitionism, and of course, Russell Paradox and Goedel type theorems. All these serve one purpose: to show that algorithmic methods are intrinsically crippled -- there are so many beautiful things in the world which we can do nothing with but to worship! Mathematics is only Penrose's pleasure, Physics is his rice bowl. He will now convince us that not only logically the world is unperceivable, but physically the world is unmeasurable to some degree! The Nature is so construed that the uncertainty principle and quantum mechanics prevent us from precisely knowing anything smaller than a quantum. Again his position in physics society allows him to take us also to a journey of Physics Tor'Bled-Nam. He guides us so easily into the classical world as if it were his hometown. Galileo, Newton, Maxwell, Lorenz, Einstein, to name a few, Penrose knows them much better than any of us does. So, of course, he assumes the job of introducing them and their world views. Not until he gloriously (with the characteristic pride of Great Britain) brings us to the quantum maze, does he emphasize the undecidability of the world again. This is the kingdom he works, where he takes a fairly good position. Maybe he is "below the one and above the all"? (I remember someone says that Hawking is the current Emperor of quantum mechanics, is it true?) Of course the controversy around the uncertainty principle and measurability of quantum states is a hot topic. You don't need a Ph.D. degree to READ this part, since Penrose designed this book for the population at large. But I am not sure if all Doctors can UNDERSTAND what is going on there. At least I am not assuming myself a position to give detailed introduction of it for this very moment. One thing that puzzles me up till now is why Penrose puts a chapter of "Cosmology and the Arrow of Time" there. Does it have anything to do with Intelligence? I assume that he didn't try to increase the cost of the book to get more author pay. Finally Roger, with his satirical tone (Gardner would call it humorous, but I am over sensitive to enjoy the fun), returns to the central topic: can computer have a mind? Of course, all evidences, mathematical, physical, evolutionary, anthropological, and so on, negate the answer. Dr. Penrose modestly calls himself a child who happens to have honestly (or with genius?) pointed out a truth that the strong AI guys are the emperors without clothes! Wow, what a beautiful new mind, people laugh and cheer, seeming that they like to see ... .