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Summary: A short review for laymen
Review: Brain Greene does a wonderful job of explaining the worlds of Relativity and Quantum physics. In layman language (understandable!) he not only explains these two theoretical pillars of physics but also shows that these two theories are in conflict with each other. Very simply, Relativity is a continuum theory whereas Quantum physics treats matter, energy, distance, and possibly time, as being small discrete units. Someday, something will have to give; the theories may merge, one may be discarded, or both discarded. A classic example of the merging is provided by Newton's Laws of Motion being modified by Einstein's Relativity. Newton's laws are an approximation-albeit a damn good one-to Einstein's equations. Perhaps Einstein's equations are also an approximation. Enter String Theory, a.k.a. Superstring.
Brian Greene's explanation of String Theory can best be summed up as lots of promise but nothing tangible which can be proven experimentally. Greene is a String Theorist par excellence, but lurking in the background of his explanations is the possibility that String Theory may be nothing more than an intellectual pursuit which has no connection with physical reality. Only time will tell. But in the meantime I recommend this book for the interested layman with the only caveat being that the String Theory portion of the book requires several readings; even then one may not completely comprehend. But theoretical physics at any level (physicist to layman) is an uncharted course into the unknown, not a leisurely and lazy summer vacation with the known!
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Summary: Distorted history, irrational physics, Barnum claims ...
Review: As a professional in theoretical physics and its history I am sorry to say -- this is not a fair popularizing book.First, be warned that Dr. Greene provides rather distorted and misleading view of some important historical issues of modern physics. His narrative is strongly twisted to support his claims that strings are here as a "natural" answer and the only game in town. E.g., Planck's struggle with the black-body radiation, as depicted by Greene, is closer to a fairytail than historical and scientific truth. The places where Greene touches statistical physics and thermodynamics are full of principally wrong statements which indicate that he has just a very superficial knowledge of these matters. His exposition of Quantum Mechanics (QM) pushes favourable but false statements about quantum "weirdness", showing that he is evidently unaware about many classical and modern works showing QM from a rational and unparadoxical perspective (starting yet from von Neumann in 1927). Greene's statements about a "fundamental" gap between QM and General Relativity (GR) are just other common mantras of the string army, indicating their superficial insight into these underlying theories. BTW, he is not indicating properly how the string concept offers a synthetizing cure. His "review" of the 20-th century physics is not only biased but also tedious, repeating notoriously well-known (but too often one-sided and misleading) statements and fairytails about physics' celebrities. As for the strings grandeur: I do not believe that there is too much hope that a rational Theory-of-Everything might be elaborated by people who exhibit so irrational views of quantum, relativistic and statistical physics, confuse distinctions between mathematics and physics, evidently do not understand probability theory and thermodynamics, etc. And of course, it is just funny to read on the same page that the M-theory is just IT, whilst still being unable to generate even basic equations, state its own principles, or even to demonstrate how standard physical equations or parameter values follow from IT. Actually, there is still NO string theory at all: it is rather a big gulash of mathematical exotic adhockeries, of formalistic ambiguous escapes, everything scrambled with grand supporting statements of Muhammad Ali. But most fundamentally: Greene, Witten, and the whole string army are pushing their philosophy that all kind of "weirdness" is just an intrinsic feature of our physical image. However, many rational physicists think that they are rather building a babel tower on sands, on the underlying theories they do not interpret rationally. I do not believe that the aim of the Theory of Everything ever was/is something of this kind. I am just sorry about so many laymen that are evidently so easily fooled by this new type of mysticism, combined with some lack of scientific modesty and honesty. In summary, Greene's "Elegant Universe" is neither an elegant image of the universe, nor an adequate narrative of modern physics and its history.
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Summary: If you ever wondered. . .and who hasn't!
Review: This book lets you recapture some of the wonder about the big questions. String theory is, quite literally the future science of everything. It is attempting to understand the nature of, well, nature. The book really highlights alot of the facinating physics of the last 100+ years. It also leads you into the murky frontiers of string theory. The author does an admirable job of making the issues easy to grasp with fine examples. But, and I find this to be a positive, he does not overly simplify the issues. I found some of the material incredibly difficult to understand (at times impossible). But I'm glad I have something to grow into. If it was too easy to grasp I would have felt a bit cheated. You don't feel like the author is talking down to you. Anyway, if you want a challenging book on the theory of "everything". I highly recommend it.
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Summary: Superstring theory as hopeful TOE.
Review: Greene, a leading string theorist, lucidly explains the central aspects of Einstein's relativity and of quantum theory -- both strong theories -- and how they conflict with each other. The implication: nature requires a deeper explanation. Philosophical reductionists and idealists (so-called Platonists, if you prefer) agree on this much, but disagree on the fundamental question of how "ultimate" any theory of physics can actually be. Early in this volume, Greene states an affinity for the reductionist's view that an ultimate theory of everything should "not require or even allow for a deeper explanatory base." Regarding the idea that an ultimate and final explanation lies within the access of scientific endeavor, he concedes that "some agree... some don't." As the book progresses into superstring theory, topology, Calabi-Yau spaces, eleven (or more) dimensions, space-time tearing, and cosmological considerations, the approach is one of generally cautious methodological reductionism, the sound scientific approach with which philosophical idealists will have little if any disagreement. In the two concluding chapters, Greene assumes a reflective and circumspect sobriety with an increasingly Platonic tone. The literary quality of the book is strong, the science as rigorous as most readers would want. "Ultimate" or not, a deeper explanation of nature is required. In Greene's words, "string theory is the only way we know of to merge general relativity and quantum mechanics." The book is an excellent presentation of the history and current state of string theories, including M-theory. But a truly "ultimate" theory? The case for that claim is clearly unconvincing, as it must be. Greene recognizes this and, in the end, the ardent philosophical reductionist, i.e. one who believes that ultimate explanations must be mechanistic and accessible to science, may be disappointed. Admitting that the reductionist's faith in a mechanistic TOE may prove to be naive, "brash posturing," he reflects, "the history of science teaches us that each time we think that we have it all figured out, nature has a radical surprise in store for us that requires significant... changes in how we think the world works." As Leibniz' cutting logic yet illustrates, the question of "how" the world works may be the ultimate question which can be addressed by science, but it is not the ultimate question. The idea that a physical theory of everything might be understood as the fully 'ultimate answer' is not a logically defensible claim, but rather a problematic article of faith. Again to his credit, Greene explains this.
The mysterious and complex world of string theory is not easily translated from its native language, that of mathematics. But with its mathematical model of the elusive graviton, string theory presents physics with an opportunity to reconcile relativity and quantum theory. Greene writes wonderfully and does an admirable job of bringing strings to the non-physicist.
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Summary: Why can't others write about science this way?
Review: Never have I seen such complex topics explained so clearly in a book. Brian Greene finds just the right analogies to make everything clearer, from Einstein's relativity theories to string theory. Perhaps the reason other science writers limit themselves to writing about the history of a scientific topic, with only vague "explanations" of the topic itself, is that they do not really understand the topic they are writing about. Greene, as a physicist deeply involved in cutting edge research on string theory, definitely understands his topic. What is amazing is that he realizes the average person will have difficulty comprehending string theory. Greene manages to explain it without dumbing it down too much.
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Summary: Down To Earth, Yet, Outta This World!
Review: I will have to say, although only those who are interested and well educated in the theories of the universe, it doesn't take a rockey scientist to understand what Brian Greene has to say. He starts the book out with a review on what the world already knows about the world. Then he gets into the nitty gritty of the 'strings' and what the world is about to discover. He touches not only on the wide realms of relativity, but involves you with quantum mechanics of which is needed to understand some of the physics of the String Theory. Greene has made this a successful book by explaining complex theories with real down to earth analogies. Most would think that this book is not for teenagers like me, but I made it through with the ability that I could even explain it to others (except 6-dimensional spheres, of which I think no one will ever understand). This book is very challenging, but yet, understandable for an entry level discovering scientist ready to learn
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Summary: Clear introduction to string theory...
Review: and a well-written primer on relativity and quantum physics. I recommend it highly.
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Summary: Physics today is stringy.
Review: Physics today is a very abstract enterprise. But do not blame the physicists. The standar model has been pretty much set from the 70's, and real experimental progress will have to wain until bigger accelerators are built. Physics is Kuhn's paradise, the science of paradigm shifting. Einstein made the universe (almost) consistent with his general and special theories of relativity. Quantum physics explained everything in probabilities, from the smallest (or not?) to the largest. These two theories, relativity and quantum mechanics, are, well, the cornerstone of modern physics (not for long!). They both have enormous support, and in fact, are (at least quantum theory) the mos succesful theory in the history of science. It has been experimentaly proved to an incredible presision. An relativity is probably the most well known theory in physics. The problem is that you cannot have your quantum cake and eat the relativity too. They are, well, incompatible. (Why? well, at small enough levels, quantum interdeminacies wreak havoc in spacetime, and thus, gravity). Enter superstring theory. The savior of physics. Or at least it seems so, and Greene, in his book, acts as he who is going to let the public know why. Greene is a brilliant physicists, a great writer, and his explanations of such strange things as supersymetry and hidden dimensions are clear enough for anyone with an open mind to understand. I mean, before reading this book, you would not even have a clue of how to even imagine a 10 or 11 dimensional universe. But I am getting ahead of myself. Because superstring theory is well, weirder than anything that has come before. But it also has the greatest potential as a theory of everything. Superstring, it turns out, can explain everything (arguably). But it is no small price to pay, to give up on everything that you believed of the universe before. And remember you had to do this also with Einstein and the quantum. It turn out the universe is made up of strings, little vibrating loops, and they are aproximately the Planck lenght. The assumption is that there is nothing in a smaller scale than the string -strings are the fundamental fabric of the universe. Every particle arises from the vibrating patterns of these strings, and thus, mathemathically, the equations unify the four forces (weak, strong, electromagnetic, gravitational) at last. The super, in supersting, is supersymetry, and it all rises clearly from the equations. The theory also requires the universe to be 10 or 11 dimensional. This book is the best expositor to date of all these strange theories. The style is lucid, at times funny, quick paced, and it is very interesting to take a peek into modern physics. And everyone should read this because it is the last stretch in understanding the universe. What Einstein did in the 1900's, supersting theorists will do for this century, and hopefully, for ever more. (Ultimate theory, remember?). The practical people will have a hard time digesting supersting theory. It turns out that the theory is almost imposible to test in principle, given that it all happens at such miniscule scales. But circustancial evidence abounds, as well as aesthetic evidence (yes, it is pretty, so it must be right) and internal consistency. This without mentioning the greatest explanatory power in physical theories. Edward Witten (the Pope of supersting theory) once said that superstring theory is a piece of 21'st century physics that by chance fell on 20'th century physicists. Well, is is now the 21'st century, so let's see what we can do with it.
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Summary: From Calabi-Yau spaces to garden hoses, Greene does it all
Review: Greene gets a slam dunk with this 'lay' book on string theory, one of the theories most cutting-edge in physics today. Starting out with some basics (special relativity, the idea of the world in spacial dimensions less than three, etc) to ease the reader into more strangely woven topics, Greene sets the stage for introducing the gems of string theory: the marriage of general relativity and quantum mechanics; the postulation that there is such thing as a 'smallest size'; using geometrical perspectives to explain particle creation, and much, much more. This book is accessible to high school students, but not below even the scientific reader. Greene will pull you in with his colorful and variegated metaphors, opening doors to complex topics, making them seem simple and 'obvious.'
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Summary: Brian Greene brings joy ... to the uninitiated.
Review: Brian Greene should be feted for his extraordinary ability to elucidate complex and abstract thoughts about string physics and make them cogent for the masses. His flair in gently leading the readers to the subtleties and insights involved to profound truths about this remarkable theory is praiseworthy. This indeed is cutting-edge physics at its best. People who have missed out on new strides modern physics has taken in the recent past should definitely give this book a read. The string theorists have tried to explain nature in the most basics of building blocks, i.e. strings - which resides in the ultra-microscopic plank-scale world - vibrating not in the 4-dimensional space-time we are familiar with but in a 10-dimensional space-time world (11 dimensional in the case of M-Theory). The extra dimensions which hasn't manifested itself experimentally or otherwise is said to be curled up in plank-scale sizes, explained by exotic mathematical models of Calabi-Yau shapes. The mere vibrations (clockwise or anticlockwise) of strings would generate the different fundamental particles(fermions) and the different force/messenger particles(bosons). One of the vibration patterns with mass=0 and a spin=2 exactly describes the elusive graviton, the messenger particle of gravitation and thus becomes the only theory to have gravitation built-in in a quantum mechanical way. SO this could be a theory of gravity - the holy grail for the physicists - and possibly the theory of everything, as it has tried to smoothen out the conflicts between quantum mechanics and general relativity - the two pillars of modern physics. This is a journey which everyone should take for the sheer joy and excitement it creates and brings you closer to the inner workings of nature.
(At times, high school physics becomes necessary to understand the finer points Mr. Greene makes.) This journey which begins with concepts about special and general relativity and then to the standard model of particle physics, gathers pace and takes you on a ride of your lifetime through hidden dimensions, calabi-yau spaces, supersymmetry, gauge symmetry, space-tearing flop and conifold transitions, M-theory, p-branes, 3-branes wrapped black holes becoming massless and then transmutating into massless photons ... and finally when the ride ends you are left thrilled, amazed, overjoyed and gasping for air !!!
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