on 10 April 2006
I agree with other reviewers that this book is not appropriate for anyone without a degree in the physical sciences. However, people who have done a degree, even in physics at a prestigious university often come out not really knowing what's going on. Courses almost exclusively focus on examineable material and so the beauty of the whole thing is lost in routine calculations and derivations. If this sounds unhappily familiar, this book is probably for you.
For me, it was probably the most engrossing book I have ever read. Penrose explains how all the various theories and theorems interact to form a beautiful and coherent whole, but does so by building on the maths rather than the broken analogies pop-science usually uses.
It is probably worth bearing in mind that he does have a rather unusual interpretation of even the most basic physical theories. The interpretations come directly from the maths, so there is certainly no crackpottery going on, though it can be a bit of work to connect back to what you already know from university. But when you do, it is the most fantastic feeling in the world, and the reason this is the only book I have ever bothered to review on amazon.
on 6 September 2009
Unless your IQ is commensurate with the number of pages in the book (1100), do not read cover to cover. The "meat" is in chapters 17 to 34, so omit the exercises and chapters 2 to 16 for a first reading, accept that many terms will be unfamiliar but that everything which is presented can be verified. When you have three months to spare, re-read the book fully. Chapters 2 to 16 gradually introduce the mathematical concepts used, and you can verify everything presented in the rest of the book.
The book is similar to a mystery story with the last chapter removed, and you desperately seek that final chapter i.e. the book is well-titled "The Road (emphasised) to Reality": it describes the journey towards an understanding of the Universe, but it fails to provide a Theory of Everything.
Penrose gives more hints about what cannot constitute a Theory of Everything than what can. String theory, of ten or eleven dimensions, is a definite non-starter (Penrose is irritating in the number of times he tells us this.), and current quantum field theory must give way to something more like twistor theory in order to account for non-local interactions (and there is a tantalising suggestion that, by explaining wave-function collapse, it could partly demystify consciousness). Einstein's gravitational theory, however, is acceptable, and - good news for those of us who had difficulty comprehending 26 dimensions - four dimensions are the flavour of the month.
This is a heavy book, in both senses of the word, but if your heroes are Einstein, Dirac, Richard Feynman, and Stephen Hawking then buy it. If they aren't, buy it anyway - they will be.
on 22 May 2007
When choosing the rating for this book I doubted between 5 and 1 stars. Why?
Well even for someone with some mathematical background (although it's been quite some time ago) this book is tough. If you're not mathematically minded you're better of with a book with less formula's and numerical examples. Although Penrose states many times one can just read "over" the more difficult parts and still get the gist of the story, I tend to disagree. His is a beautiful treaty on the most important mathematical theories that we have at the moment and that are used in physics or more specifically cosmology. He builds a well thought out "story" that should give the reader a thorough insight in the building blocks of physical theories. If you skip over the mathematical explanations you miss the basis upon which the rest of the book is leaning. I think some understanding (more then just basic) is necessary to appreciate the wonders of cosmology, at least as presented in this book.
If on the other hand you have a firm grip on maths and are not afraid to extend this knowledge, then Penrose will keep you busy for many weeks and lets you peek at the wonders of cosmology.
So depending on your scientific background and appetite for maths, this is a great adventure or frustrating Herculean task.
on 18 August 2004
Bravo to Penrose and his publishers for daring to lay this before the general reader! This review is really for those like me who have had no formal mathematical training beyond the age of 15, yet wish to understand as best they can how the universe exists and unfolds. Penrose doesn't give up on us before he's started and just give us the gloss, he treats us as real willing students. I'm only up to chapter 11 so far, and many parts of it are certainly hard work - an evening may be spent on 3 or 4 pages. But he is a good teacher, and works hard at taking the reader deeper in successive steps. Those without a mathematical background will still need to consult other books, or skip bits, but it is a valiant effort. With a long way to go yet I feel sure the thought and concentration required will be amply rewarded. Why should these things be understood only by the cognoscenti? Penrose and his publisher's have been brave in producing this fine work. Be brave and read it!
on 8 December 2007
Eventually History remembers the great books - "The Road to Reality" is a true work of art, destined to be a classic - It is the first genuine attempt to cover in one book the state of theoretical physics today. Where other popular science books attempt to simplify the theory and omit equations, thereby reducing themselves to talking about the theory ... "The Road to Reality" PRESENTS the theory. It is a subtle, but important difference that I will try to illuminate in the rest of this review.
"The Road to Reality" makes the modern theories of physics easily accessible to mathematicians and layman alike, in a self-contained text. It achieves this by virtue of being the first popular science book on theoretical physics to devote its first 16 chapters to introducing the reader to the pre-requisite Mathematics and `Philosophy of Science' necessary to understand the theoretical physics presented in chapters 17 to 34. The book is littered with necessary equations, but all are introduced in a logical, intuitive manner and provided with some of the best explanations in words and pictures that I have seen to date.
As such the equations can be viewed merely as markers in the text if reading as a popular science book. Conversely they can be used to guide the serious theoretical physicist in attempting the minimal but carefully chosen and difficult exercises, and any mathematical investigations the reader may be inspired to conduct themselves upon reading the beautiful exposition of physical theories of our universe.
As justified above, the best thing about the book is its 1094 pages can be read at various levels .... from a cursory glance (genuinely constituting popular science, albeit a difficult read) or as serious academic study (taking you well into a post-graduate level appreciation of mathematics and theoretical physics). For the academic, it will accelerate your path to becoming a rounded theoretical physicist. Every school should own this book and every potential student of maths or theoretical physics should attempt to read it pre-university.
There is no room for dubious analogies in "The Road to Reality", which removes the scope for confusion. Apologies to those readers who like analogy, but there is no place for it in theoretical physics - Communicating an understanding of what the theory is really about, to a level that it seems intuitive to the reader, is the goal of this book.
It's my favorite book of all time. I can't recommend it more highly than that!!
on 11 July 2007
Ohter reviews focus on whether the book is easy to understand or not, or wheter it is too big or not. And it would seem that
the only purpose of the book is to put all togheter the physical laws mankind knows.
But this is a book with a message. A message that takes very long to transmit and Penrose chose to start from the very begining.
A significant part of the physics as it is known today is exposed in a long (900 pages) preamble, but Penrose wants to tell
us that he believes that the road to the Theory of Everything that is standard in today's physics leads nowhere.
If you have read "The Emperor's new mind" you know that Penrose's ideas are not mainstream in today's physics. But if you are
interested in cutting edge physics you'll also know that there is a growing number of physicists that believe that the field is on crisis. Let me sumarize Penrose views:
- The standard interpretations of quantum mechanics are wrong. Even the decoherence approach.
- Infactionary cosmology cannot be right.
- Superstring theory is just a beautiful mathematical construction with no connection to the physical world. His point of view is similar to Smolin's ("The trouble with physics").
I'm not at all an expert on the field, although I studied quantum mechanics in the University, and I'd say that at least Penrose has a very strong point. He is not able to provide but hints of alternative theories but this does not lower the merit of the book.
He also explains standard areas of mathematics and physics such as complex number calculus, Maxwell fields or group theory in a non-conventional but brilliant way. For example, it includes a beautiful demonstration of Pythagoream theorem. The chapter about the standard model of particle physics is particularly helpful; nowhere else can be found a concise and understable explanation of it.
And yes, the book is difficult, but if you don't understand the mathematics, just keep reading.
on 16 December 2006
This is an extraordiarily long book written from an unusual perspective.
I think the author is absolutely correct in describing himself as "incurably optimistic" in assuming that lay readers will be able to follow the arguments in the book. It takes many years to learn the calculational techniques of complex analysis, differential geometry and topology, and to assume a reasonably gifted, but untrained reader can follow the details is asking a bit too much. That said, I think the book would be extremely useful for someone working in the field as an overview of diverse areas of Mathematical Physics. Unfortunately, this restricts the target audience significently.
The author tries hard to be honest and open about the times when he is presenting his own opinions which are not generally accepted by the scientific community, which is much appreciated. An alternative perspective to the followers of the String Theory bandwagon is always welcome !
If the potential reader is looking for a layman's level introduction to Theoretical Physics, I would recommend t'Hooft's "In Search of the Ultimate Building Blocks", or for General Relativity, Hawkings "Brief History of Time".
on 12 December 2004
Having finally finished this book, i am still undecided whether this is the best book on general physiscs i ever read or if it is just too plain complicated to be ever fully understood by non-(thoretical) physicists.
The book starts with lots of mathematcis (ch. 1-16) to give the reader the background for the following chapters. The math is presented in an unusual way. Penrose tried to fit in all the math needed but he tried to avoid the proofs and technicalities of most of the statements. The reader, if not already familiar with advanced math, is overwhelmed by the mass of definitions and new concepts.
Sadly, most of the rest of the book depends exactly on the math of the first few chapters, so if you got lost there you probably won't recover and stay confused for the rest of the book.
However, the physics Penrose presents covers almost all the modern developments in almost all fields of physics and merely by reading (though not understanding) about all those topics i felt the fascination and beauty that lies behind them, and was encouraged to have a look at topics like general relativity in a more spelled out way in other books.
I feel that the main reason Penrose wrote this book is to accomplish exactly that:
Encourage readers all over the world to get into these topics, read more about them, and maybe finally take a step further on the road to reality. (see Epilogue)
If you are looking for an illustrative and popular read on modern physics, get Greene or Hawkins.
If you want a signpost to decide what to read next, Penrose will help you find the right way.
If the maths hurt you...don't give up, do persevere as this book is amazing. Read it carefully and slowly even if it's just a page a day. If you find that you are really stuck and need an alternative method of concieving complex concepts then use wikipedia or mathworld.com as a reference back-up or second narrative. Although you can skip the math-heavy bits and just read the text and get a vaguely decent understanding of physical laws, but to do so would be to deny yourself the extraordinary beauty and elegance of mathematical reasoning as applied to universal phenomena.
This book is unique - Proffesor Penrose is among the best mathematical physicists of the modern era and yet he has sufficient empathy with the lay-man to take you by the hand and guide from the very basics of pythagoras up to the giddy-heights of quantum mechanics.
on 31 January 2016
This is the book I've always wanted, everytime I read a "pop sci" book on physics (usually string theory related in fairness) I've thought, gee, I wish they went over the mathematics of it just to be sure it isn't an empty analogy.
Boy was I wrong! Chapters 1-17 at terse, dense and lifeless mathematics dotted with convoluted analogies. I've had 3 cracks at reading it and never made it beyond chapter 4 (unless I simply skim over it). Now, I'm not entirely "non-mathematical" and do have a Bachelors in "imaging sciences" which covered the physics and mathematics of medical imagers -- I am au fait with the particle physics and some of the mathematical tools employed in it( well I was about 5 years ago!). But still very quickly this book escapes me.
Chapters 18-34 concentrate on the physics and Penrose assures you, you can skip the maths and equations. Yes you can but what you get is a bullet point list of ideas and no explanation. I'd rather a well throughout analogy found in other books than one where I simply don't understand the maths.
This book fails to provide you with what it advertises. It does not provide you with an understandable background in mathematics.
It's like someone provided you the intro and examples for a undergraduate course in Physics... without any teaching. I am sure that some people out there would be able to make use of this book, but I feel if you understood the maths in this book you probably don't need it as you most likely are a physicist.