The Road To Reality: A Complete Guide to the Laws of the Universe [Paperback]

This book certainly seems to polarise opinions. I have yet to read a neutral review of it. It is either praised to the skies or condemned as useless. It doesn't take a Penrose (or an Aristotle) to point out that these two views are logically incompatible!.
I have a good deal of sympathy with the reviewer who got as far as chapter 6 before giving up in disgust. I have got just a little bit further at the cost of considerable effort. However I do not think the book is useless and I'm sure some readers will genuinely enjoy it.
There are a few problems. Firstly the blurb is plain dishonest. Secondly Penrose's preface in which he states that it is possible to read the book and gain something from it whilst skipping most of the maths is hopelessly naive and optimistic.
Make no mistake about it, if you do not enjoy Maths for its own sake you are not going to get very far with this book.
Like several of your other reviewers I studied Maths at school and enjoyed it .
I then went on to study Medicine at university and have always nursed a vague sense of inferiority about my "school boy" Maths.
I believe anyone who tackles the book with this kind of background is going to struggle pretty badly and more specifically they are going to get stuck on chapter 7 ("Complex number calculus").
Personally I read the first 6 chapters with enjoyment and even managed to do some of the examples. It started me thinking again about the Maths I had learned long ago and I found that I enjoyed doing so. Further Maths books were purchased and most outside observers are of the opinion that I have wasted a good deal of time (I have however enjoyed myself in a strange sort of way.)
I now understand (to my own satisfaction at least) most of the first 6 chapters. It has to be said that I learned very little of this from actually reading Penrose's book on its own. I found further reading essential. Penrose presents only the barest bones of the subject and expects a great deal from the reader in terms of thinking for him or herself. There is absolutely no "spoon feeding". The prose is dense and takes some getting used to, however I think he does manage to communicate a sense of excitement in the subject.
The approach is unconventional but I have found that if something is already well understood ( by learning it at a more leisurely pace elsewhere) then Penrose's take on the subject can be quite illuminating. For example his approach to the exponential form of a complex number via an informal but convincing definition of a complex logarithm is far easier to grasp intuitively than the usual power series proof.
So far so good. No more school Maths after chapter 6!
Before reading this book I had never heard of complex calculus. Perhaps I flatter myself but I don't honestly believe anyone unfamiliar with this subject will gain anything more than a headache by reading chapter 7. I read and re read this chapter several times before giving up and skipping to chapter 10 ("Surfaces") which seemed to be related. I got on better with chapter 10 and realised I had completely missed the point of chapter 7. Why the hell didn't he put chapter 10 first? Having said this chapter 10 is still very difficult and I got so frustrated with it that I went out and bought an introductory text on vector calculus.
After reading this (and this stuff is pretty challenging in spaces that are flat. No one is going to glide through this) and then doing a bit more research on the web I think I have got as far as seeing what Penrose is trying to explain in chapters 10 and 12 ("n-dimensional manifolds") .This of course is not the same thing as actually understanding it.
If I ever do understand it (unlikely) then chapter 19 ("The classical fields of Maxwell and Einstein", 29 pages in all) should be a walk in the park ,I will have finished with classical physics for good and can start the difficult stuff!
Penrose clearly hopes that by explaining the essential concepts behind a subject and leaving out what (to him) are unnecessary computational details the reader will gain enough insight to grasp the essentials.
As I have said before the man is an optimist. Intelligent people can sometimes take intuitive short cuts with subjects they understand well. Beginners don't stand a chance.
If you enjoy Maths but don't have a degree in it ,are very well motivated to understand some of modern physics and have grown inpatient with the usual popularisations by all means buy this book.
I don't honestly think most people will finish it. If however your curiosity is aroused and in defiance of common sense you become infected with Penrose's incurable optimism you will buy a lot more books, blunt a few pencils and severely test the patience of your family and friends. You might even learn something.
Alternatively you could always stain it with coffee, make spurious notes in the margin and display it prominently on your shelf where everyone will see it. I suspect this last motivation will sell a lot of copies!

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.

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!