No me lo terminé ni tiene pinta de que lo vaya a hacer. Aprecio al autor y los libros de divulgación científica; y la primera mitad, aun siendo complicadilla de pillar se hace bastante interesante, ayudando a pillar los conceptos básicos de la mecánica cuántica y la teoría de la relatividad. Sin embargo, la parte que trata propiamente acerca de la teoría de cuerdas empieza bien pero acaba siendo excesivamente enrevesada y poco atractiva. Los últimos capítulos que leí eran infumables y no tenían pinta de mejorar.

Aún así, oye, si te mola la física no está mal.

Do I understand general relativity now? Yes. More than before anyway.
Do I understand string theory? Uh… nope.
Do I understand M theory? Nope. Not even a little bit.
Can I describe a Calabi-Yau? Nope. Not a chance.
Do I have any opinions on the validity of this theory? Nope. I just don’t understand it nor the conflicting theories enough to even begin to opine on any of them.
Did I enjoy the book? Yes. Attempting it made me feel smart. Until, I realized just how much of this book flew lightyears over my head, as it became painfully obvious that I was in desperate need of all of those wonderful illustrations. So dutifully chastened, I settled in for an informative enjoyable read. The early chapters were by far the best, or at least the easiest to understand.
Do physics and math explain the formation of the universe or its existence? No. And they certainly won’t explain the existence of sentient beings either. So that part of the author’s goal was a failure as far as I am concerned. But then the author himself only holds out hope that they someday will answer all those questions. I did appreciate that about this book. Greene is quite open about the extremely speculative nature of the vast majority of this book.
Do I recommend it? I guess… I don’t know. I liked it, but with anything so speculative, that I don’t understand, I can’t begin to fully vouch for it.

The Elegant Universe explains the famous string-theory, and also touches on general relativity and quantum mechanics.

I'm not a particularly smart person, but I'd heard that this book was very readable even for people without knowledge on the subject. And parts of the book definitely was. There was a lot of very nice analogies and explanations - but the opposite is also true. I also don't really feel like I gained all that much from reading this. Like, I still don't know very much about string theory. Overall, I do not think this is a very good book, but the easily readable parts of the book, with their analogies and what not, prevent it from getting bottom score from me. So two stars from here.

String theory is undoubtedly one of the most beautiful theoretical frameworks in the scientific realm. It is however quite daunty with all the extra curled up hidden dimensions and a whole bunch of supersymmetric partner particles, none of which have been discovered. Regardless of whether it's true or not, this theory shows how far the human mind has come. Brian Greene is able to dumb down on the complexities of this theory while not omitting them so as to give readers a basic understanding of what is going on.

Not enough science and too much wildly imaginative suppositions. Every other topic was followed with, “unfortunately, we don’t have the knowledge or technology to substantiate this yet.” After a while, it felt like the author would have been a perfect stand-in for that guy with the crazy hair on Ancient Aliens. It was hard not to switch “string theorists believe” with “alien astronaut theorists believe.” I definitely came out of this having more questions than when I started, but not in a good way.

I love this book! Now I admit, I’m a maths guy, but I found dipping in and out of this to be so much fun. Complex stuff presented simply, if you like maths, you’ll most likely love this too.

Even though string theory is perhaps a little unsteady or doesn’t quite have a strong hold in the current age, this book still has a lot to contribute.

Admittedly, this book is not for the beginner and anyone reading this will benefit from some previous foundation or experience in physics, quantum mechanics as well as the subject matter. I’ve read a fair bit around this topic and did found myself lost a few times however the author does have a great way of explaining certain scenarios and fundamentals in easier to understand ways which did really help.

Also it was interesting to see the hurdles and difficulties faced for string theorists and those on the sides of this corner of physics and I loved reading about the history and the evolution that string theory has gone through as well as the research that has been done and hopeful directions for the future.

The book also explained and laid down the foundations to further help you understand the topic such as special and general relativity as well as E=MC2 and classical, quantum and Newtonian mechanics. There is a lot of information in this book and I particularly enjoyed the chapter on the Big Bang Theory and the possibility of M-theory.

This book certain does paint the picture of The Elegant Universe and I’m glad I read it which has somewhat expanded my horizons on learning about the universe. I’ve enjoyed other Brian Greene books as well as this one and he has a very logical smooth flow of writing which can also be found within this book. A very elegant universe indeed!

Read it twice now - I love it even though I don't understand it all, the snippets I do 'get' are wowsicles.

It's been quite some time since I've read a popular physics book, so I enjoyed the first part of The Elegant Universe, which is a good introduction to the core concepts of physics including Relativity and Quantum Mechanics. This was a good refresher and helped to solidify these concepts in my mind, as well as reminding me of a few things I'd forgotten over the years.

I enjoyed the rest of the book less, for a number of reasons. Firstly, the science around String and M theories is much less settled, and is more speculative. As a lay person with only very light exposure to developments in the field, it is impossible for me to determine what is accepted science and what is hopeful conjecture. Greene obviously has a dog in this fight, and so I'm not entirely comfortable with taking his opinion as fact. Also, this book was written in 1999, and surely the field has developed significantly since then. So I took the the whole section around String and M theory with a massive grain of salt. And honestly the approach to explanation in this section is not as good as early in the book - he focuses more on his personal involvement and the work of his colleagues, rather than on exploring the underlying concepts in detail.

On an aesthetic level, there is something about these theories - actually much of the standard model, especially supersymmetry - that I find unconvincing, and although I accept that the scientific nature of reality does not hinge on aesthetics, it's difficult for me to ignore this personal bias. The theoretical components seem so piecemeal and inelegant, like the model has been squeezed and distorted in order to fit the experimental data, and the result is just a mess, with good predictive but little real explanatory power. It may work mathematically, but it seems strange for such a generally elegant and orderly universe to be based on such arbitrary principles. A good comparison would be with orbital epicycles, which were adequate predictive models, but are messy and inelegant and were eventually replaced by Newton's simpler and far more elegant solution to the problem - Newton's paradigmatic innovation being to consider elliptical orbits rather than circular ones. It seems as though we are at a similar stage with the current state of the Standard Model - inventing patches and workarounds to fit with the experimental data, and waiting for a paradigm shift for the pieces to fall into place. String and M theory go some way toward trying to address this, but even if they were experimentally validated, the model is still not satisfying and it's difficult not to imagine that there is still some deeper understanding that is eluding us.

De vez en cuando surge un maestro de la divulgación científica. Brian Greene saltó a la fama de la divulgación científica con este libro. Se trata de una introducción a la teoría de cuerdas, una de las estructuras intelectuales más complejas paridas por la mente humana. El estilo es muy claro y ameno -se ve que el autor se divierte escribiendo- y resulta una lectura apasionante y muy enriquecedora incluso para lectores con formación física, pues las ideas de las que habla no están en la carrera. El libro tuvo tanto éxito que hasta hicieron un documental, con el propio Greene como presentador. Y es un documental muy bueno. Los lectores pueden descargárselo gratuitamente (en inglés) de aquí. Ahora Greene ha sacado un nuevo libro, The fabric of Cosmos, que he empezado a leer. En él se habla de la estructura del espaciotiempo, nada menos, pero el estilo sigue siendo ameno. Y el libro es muy interesante, desde luego. Mi nota para éste es Muy, muy bueno.

For me, "The Elegant Universe" is the book that started it all. Greene has such a smooth way of easing the novice into the complexities of string theory, the reader feels almost acquainted by the time the science is introduced. Never boring or tedious, Greene deftly guides us through the basics of relativity, explains the importance of frames of reference, and eases us into the almost magical world of gravity and timespace.
Like Einstein, Greene presents the science through simple visuals - balls and bicycles, funny cars and cartoon spaceships. The reader will never feel as though he sits in a classroom with a boring professor droning away the afternoon. Instead, Greene describes the physics in a real world way and in doing so, prepares even the most casual student for the truly strange world of strings.
String theory appears to be the road to a unified theory, the long sought Theory of Everything that will unite relativity and quantum mechanics. Along the way is a wonderous world of possibilities, with extra dimensions, parallel worlds, and all the while, tiny strings vibrating the symphony of the universe.
I read this book with a zeal normally reserved for action novels. Each night was a new lesson and a new glimpse at a different part of the universe. Greene's gift is a clear and friendly writing style that makes this heavy science accessible to those of us without a string of initials at the end of our name.
Many physicists came before Greene and others have followed suit. But for me, "The Elegant Universe" is the book that opened my eyes to the mind blowing world of strings and the possibilities they present. And I've been hooked on string theory since. I recommend this book to anyone who has ever looked at a sky full of stars and wondered what it's all about.
Mark LaFlamme, author of "The Pink Room"

Greene can explain complicated theories better than anyone. I read the best explanation of Einstein’s general and special relativity theories. Especially when when we see an object travelling at high speed, they appear the age more slowly. But the same applies to the other side looking at us, making us age more slowly from their standpoint! This is perfectly fine unless they want to meet up, and one side accelerates to meet the other one. In this case the accelerating side will find they indeed had aged much more than the side being caught up. Had gravity bends space time itself, and we always travel at light speed; any other movement slows down time itself.

Nobody really understands quantum physics, like a photon behaves like a particle when passing through one slit but when faced with double slit it interferes with itself and show wave interference patterns. Particles can appear and disappear spontaneously. Shrodinger’s cat is both dead and alive until one looks and collapses its wave function.

Gravity stumps quantum physics because when quantum equations are applied to gravitons, infinite solutions appear. So string theory comes to the rescue.

So strings are fundamental stuff of everything, the real Greek Atoms. They coil up in 3 big dimensions and many tiny dimensions. Unfortunately this is untestable and thus lots of maths and imagination are required. In the end, the M theory which is a master theories of all string sub-theories is proposed. 10 physical and 1 time dimension.

I must say I am a but lost from that point onwards, because of lack of experimental support. To identify strings. we would need an impossibly large amount of energy so we may Never be able to prove its existence. It is tough to actual acknowledge that we may never be able to go much further in particle physics, but such is life.

The best physics book I have ever read.